CN101465598B - AC/DC converter - Google Patents
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Abstract
Translated fromChinese
Description
Translated fromChinese技术领域technical field
本发明涉及交流/直流(AC/DC，Alternating Current/Direct Current)电压变换技术，特别涉及一种AC/DC变换器。 The invention relates to alternating current/direct current (AC/DC, Alternating Current/Direct Current) voltage conversion technology, in particular to an AC/DC converter. the
背景技术Background technique
AC/DC电压变换电路是将交流电压变换为直流电压的电路，广泛应用于直流稳压电源、直流电动机、工业焊接以及通信等领域。通过对交流电压进行滤波整流、稳压、电压变换、输出滤波整流以及稳压，输出稳定的直流电压，满足生产、生活中对各种直流稳压电压的需求。 The AC/DC voltage conversion circuit is a circuit that converts AC voltage into DC voltage, and is widely used in DC regulated power supplies, DC motors, industrial welding, and communications. Through filter rectification, voltage stabilization, voltage conversion, output filter rectification and voltage stabilization of AC voltage, stable DC voltage is output to meet the needs of various DC stabilized voltages in production and life. the
图1为现有AC/DC变换器的结构示意图，参见图1，该AC/DC变换器包括：输入电压电磁干扰(EMI，Electro Magnetic Interference)滤波电路、功率因数校正(PFC，Power Factor Correct)电路、DC/DC变换电路以及输出电压滤波电路，其中，输入电压EMI滤波电路、PFC电路和DC/DC变换电路为输入电压初级侧电路，输出电压滤波电路为次级侧电路， Figure 1 is a schematic structural diagram of the existing AC/DC converter, see Figure 1, the AC/DC converter includes: input voltage electromagnetic interference (EMI, Electro Magnetic Interference) filter circuit, power factor correction (PFC, Power Factor Correct) circuit, DC/DC conversion circuit and output voltage filter circuit, wherein, the input voltage EMI filter circuit, PFC circuit and DC/DC conversion circuit are the input voltage primary side circuit, and the output voltage filter circuit is the secondary side circuit,
输入电压EMI滤波电路，用于对输入的交流电压进行整流滤波，例如，进行全桥、π型等整流滤波，以滤除交流电压包含的谐波和通过电网传输的谐波后输出至PFC电路； The input voltage EMI filter circuit is used to rectify and filter the input AC voltage, for example, perform full-bridge, π-type rectification and filtering, to filter out the harmonics contained in the AC voltage and the harmonics transmitted through the power grid, and then output to the PFC circuit ;
PFC电路，用于对输入电压EMI滤波电路输出的电压进行功率因数校正并稳压到预设值，用以提高变换器的功率因数，满足国际有关技术标准关于谐波的技术要求，减小对电网的谐波污染，从而也提高变换器的工作效率； The PFC circuit is used to correct the power factor of the voltage output by the input voltage EMI filter circuit and stabilize the voltage to a preset value, so as to improve the power factor of the converter, meet the technical requirements of relevant international technical standards on harmonics, and reduce the impact on Harmonic pollution of the power grid, thereby also improving the working efficiency of the converter;
DC/DC变换电路，用于对PFC电路输出的稳压电压进行直流电压变换，将PFC电路稳压到预设值的电压变换为相应负载所需要的直流稳压电压； The DC/DC conversion circuit is used to perform DC voltage conversion on the regulated voltage output by the PFC circuit, and convert the voltage regulated by the PFC circuit to a preset value into the DC regulated voltage required by the corresponding load;
输出电压滤波电路，用于对DC/DC变换电路输出的电压进行滤波，以 进一步提高输出的负载所需要的直流稳压电压的稳定性。 The output voltage filter circuit is used to filter the voltage output by the DC/DC conversion circuit to further improve the stability of the DC stabilized voltage required by the output load. the
现有的PFC电路，由于PFC技术的迅速发展以及推广应用，其电路拓扑结构形式多种多样，都具有很好的输入和输出特性，以下以实际应用中较常见的一种电路为例进行具体说明。 The existing PFC circuit, due to the rapid development and application of PFC technology, has a variety of circuit topologies, all of which have good input and output characteristics. The following is a more common circuit in practical applications as an example. illustrate. the
图2为现有一种常见的PFC电路结构示意图，参见图2，该PFC电路包括：二极管D1～D7、电感L1、电阻R0、电容C1以及开关管Q，其中， Figure 2 is a schematic diagram of an existing common PFC circuit structure, see Figure 2, the PFC circuit includes: diodes D1~D7, inductor L1, resistor R0, capacitor C1 and switch tube Q, wherein,
二极管D1～D4用于组成整流电路，对输入的交流电压ACin进行整流，D5～D7、电感L1、电阻R0、电容C1以及开关管Q1用于对整流后的ACin进行功率因数调节，以提高输出的直流电压DCout的功率因数，这样，可以提高变换器的效率，同时，对整流后的ACin进行稳压以及滤除谐波，使输出的直流电压DCout满足有关技术标准。下面描述中，将PFC电路输出的直流电压DCout称为PFC母线电压。 Diodes D1~D4 are used to form a rectification circuit to rectify the input AC voltage ACin , D5~D7, inductor L1, resistor R0, capacitor C1 and switch tube Q1 are used to adjust the power factor of the rectified ACin to Improve the power factor of the output DC voltage DCout , so that the efficiency of the converter can be improved. At the same time, the rectified ACin is stabilized and harmonics are filtered, so that the output DC voltage DCout meets the relevant technical standards. In the following description, the DC voltage DCout output by the PFC circuit is referred to as the PFC bus voltage.
图2所示PFC电路的工作原理为：交流电经整流桥整流后，经过一个储能电感和隔离二极管输出稳定的直流电压，储能电感与隔离二极管的连接点通过一个互补金属氧化物半导体(MOS，Metal Oxide Semiconductor)开关管接地，MOS开关管栅极上的控制电压为恒定电压，这样，使得MOS管按照预定的时间点不断地进行开通与关断的切换，从而调节通过储能电感的电流，使电容通过充放电维持输出直流电压的稳定，同时也消除了由于整流滤波产生的谐波电流，补偿、提高功率因数。 The working principle of the PFC circuit shown in Figure 2 is: after the alternating current is rectified by the rectifier bridge, a stable DC voltage is output through an energy storage inductor and an isolation diode, and the connection point between the energy storage inductor and the isolation diode is passed through a complementary metal oxide semiconductor (MOS , Metal Oxide Semiconductor) switch tube is grounded, and the control voltage on the gate of the MOS switch tube is a constant voltage, so that the MOS tube is continuously switched on and off according to the predetermined time point, thereby adjusting the current passing through the energy storage inductor , so that the capacitor maintains the stability of the output DC voltage through charging and discharging, and at the same time eliminates the harmonic current generated by rectification and filtering, and compensates and improves the power factor. the
PFC电路的输出与DC/DC变换电路相连接，DC/DC变换电路需要根据各种负载对直流工作电压的要求以输出相应的直流电压，因而，DC/DC变换电路需要针对各种不同的负载，对电路的一些参数进行调整，以保证稳定且符合技术规范要求的输出电压。 The output of the PFC circuit is connected to the DC/DC conversion circuit. The DC/DC conversion circuit needs to output the corresponding DC voltage according to the requirements of various loads for the DC operating voltage. Therefore, the DC/DC conversion circuit needs to be aimed at various loads. , adjust some parameters of the circuit to ensure a stable output voltage that meets the requirements of technical specifications. the
现有DC/DC变换电路包括：移相全桥零电压开关变换器、脉宽调制(PWM，Pulse Width Modulation)控制全桥变换器、对称半桥变换器、半桥三电平DC/DC变换器、级联全桥三电平DC/DC变换器、全桥三电平DC/DC变换器、移相全桥变换器以及各种降压/升压(BUCK/BOOST)类变 换器等。下面以移相全桥变换器为例，详细说明DC/DC变换电路的DC/DC直流变换工作原理。 Existing DC/DC conversion circuits include: phase-shifted full-bridge zero-voltage switching converter, pulse width modulation (PWM, Pulse Width Modulation) controlled full-bridge converter, symmetrical half-bridge converter, half-bridge three-level DC/DC conversion converters, cascaded full-bridge three-level DC/DC converters, full-bridge three-level DC/DC converters, phase-shifted full-bridge converters, and various buck/boost (BUCK/BOOST) converters, etc. . Taking the phase-shifted full-bridge converter as an example, the working principle of the DC/DC conversion of the DC/DC conversion circuit will be described in detail below. the
图3为现有移相全桥变换器电路结构示意图，参见图3，该移相全桥变换器电路包括：初级侧直流电压调节电路以及次级侧直流电压输出电路，其中， Fig. 3 is a schematic structural diagram of an existing phase-shifted full-bridge converter circuit. Referring to Fig. 3, the phase-shifted full-bridge converter circuit includes: a primary-side DC voltage regulation circuit and a secondary-side DC voltage output circuit, wherein,
初级侧直流电压调节电路，包括超前桥臂、滞后桥臂以及原边线圈，用于根据负载工作电压的要求调节超前桥臂、滞后桥臂通断的时间，从而保持通过原边线圈变换的直流电压的稳定以及输出相应的负载工作电压， The primary side DC voltage regulation circuit, including the leading bridge arm, the lagging bridge arm and the primary side coil, is used to adjust the on-off time of the leading bridge arm and the lagging bridge arm according to the requirements of the load operating voltage, so as to maintain the DC transformed by the primary side coil The stability of the voltage and the output of the corresponding load working voltage,
超前桥臂，第一端分别与PFC电路输出的直流电压DCout(PFC母线电压，在图3中，以Uin表示)的正极以及滞后桥臂的第一端相连，第二端分别与Uin的负极以及滞后桥臂的第二端相连，第三端与原边线圈一端相连，第四端接收超前桥臂控制信号， The first end of the leading bridge arm is respectively connected to the positive pole of the direct current voltage DCout output by the PFC circuit (PFC bus voltage, represented by Uin in Figure 3) and the first end of the lagging bridge arm, and the second end is respectively connected to U The negative pole ofin is connected to the second end of the lagging bridge arm, the third end is connected to one end of the primary side coil, and the fourth end receives the control signal of the leading bridge arm.
滞后桥臂，第三端与原边线圈另一端相连，第四端接收滞后桥臂控制信号， The lagging bridge arm, the third end is connected to the other end of the primary side coil, and the fourth end receives the lagging bridge arm control signal,
超前桥臂控制信号超前滞后桥臂控制信号预先设定的相位，该预先设定的相位与Uin、原副边线圈匝数比以及负载所需的直流电压大小有关，在Uin、原副边线圈匝数比以及负载的直流电压确定后，该相位可通过预先设置的程序自动计算获取，调节控制信号相位的方法，具体可参见相关的技术文献，在此不再赘述。 The pre-set phase of the leading bridge arm control signal leads the lagging bridge arm control signal. The pre-set phase is related to Uin , the turns ratio of the primary and secondary coils, and the DC voltage required by the load. After the turns ratio of the side coil and the DC voltage of the load are determined, the phase can be automatically calculated and obtained through a preset program. For the method of adjusting the phase of the control signal, please refer to relevant technical documents for details, and will not repeat them here.
超前桥臂包括：MOS开关管Q11和Q21， The advanced bridge arm includes: MOS switch tubes Q11 and Q21,
Q11，包括第一极、第二极以及控制极，在第一极和第二极之间，并联有二极管D11和电容C11， Q11, including the first pole, the second pole and the control pole, between the first pole and the second pole, a diode D11 and a capacitor C11 are connected in parallel,
Q21，包括第一极、第二极以及控制极，在第一极和第二极之间，并联有二极管D21和电容C21， Q21, including the first pole, the second pole and the control pole, between the first pole and the second pole, a diode D21 and a capacitor C21 are connected in parallel,
Q11的第一极分别与Uin的正极以及滞后桥臂的第一端相连，第二极分别与Q21的第一极以及原边线圈一端相连，控制极接收Q11控制信号， The first pole of Q11 is respectively connected to the positive pole of Uin and the first end of the lagging bridge arm, the second pole is respectively connected to the first pole of Q21 and one end of the primary side coil, and the control pole receives the control signal of Q11,
Q21的第二极分别与Uin的负极以及滞后桥臂的第二端相连，控制极接 收Q21控制信号， The second pole of Q21 is respectively connected with the negative pole of Uin and the second end of the lagging bridge arm, and the control pole receives the Q21 control signal,
Q11控制信号与Q21控制信号互补。 The Q11 control signal is complementary to the Q21 control signal. the
滞后桥臂包括：MOS开关管Q31和Q41， The lagging bridge arm includes: MOS switch tubes Q31 and Q41,
Q31，包括第一极、第二极以及控制极，在第一极和第二极之间，并联有二极管D31和电容C31， Q31, including the first pole, the second pole and the control pole, between the first pole and the second pole, a diode D31 and a capacitor C31 are connected in parallel,
Q41，包括第一极、第二极以及控制极，在第一极和第二极之间，并联有二极管D41和电容C41， Q41, including the first pole, the second pole and the control pole, between the first pole and the second pole, a diode D41 and a capacitor C41 are connected in parallel,
Q31的第一极分别与Uin的正极以及Q11第一极相连，第二极分别与Q41的第一极以及原边线圈另一端相连，控制极接收Q31控制信号， The first pole of Q31 is respectively connected to the positive pole of Uin and the first pole of Q11, the second pole is connected to the first pole of Q41 and the other end of the primary side coil respectively, and the control pole receives the control signal of Q31,
Q41的第二极分别与Uin的负极以及Q21第二极相连，控制极接收Q41控制信号， The second pole of Q41 is respectively connected with the negative pole of Uin and the second pole of Q21, and the control pole receives the control signal of Q41,
Q31控制信号与Q41控制信号互补。 The Q31 control signal is complementary to the Q41 control signal. the
Q11、Q21、Q31以及Q41控制信号由PWM控制器(图中未示出)输出，PWM控制器根据输出负载的直流电压要求，通过控制回路(图中未示出)按照预先设定的策略输出控制信号，控制加在MOS开关管Q11～Q41上控制极上的电压，从而控制Q11～Q41的通断时间(占空比)，调节输出至原边线圈N1两端的电压，使得输出至负载的电压稳定在该负载所需的工作电压上。 The control signals of Q11, Q21, Q31 and Q41 are output by the PWM controller (not shown in the figure), and the PWM controller outputs according to the preset strategy through the control loop (not shown in the figure) according to the DC voltage requirement of the output load The control signal controls the voltage applied to the control electrodes of the MOS switch tubes Q11~Q41, thereby controlling the on-off time (duty ratio) of Q11~Q41, and adjusting the voltage output to both ends of the primary coil N1, so that the output to the load The voltage is stabilized at the operating voltage required by the load. the
次级侧直流电压输出电路，用于将原边线圈变换的直流电压输出，包括副边线圈N21和N22，二极管Dr1和Dr2，二极管Dr1和Dr2构成中心抽头的整流电路，通过输出滤波电感L0连接到输出滤波电容C0，其中， The secondary side DC voltage output circuit is used to output the DC voltage transformed by the primary side coil, including secondary side coils N21 and N22, diodes Dr1 and Dr2, and diodes Dr1 and Dr2 form a center-tapped rectification circuit, which is connected through the output filter inductor L0 to the output filter capacitor C0, where,
N21和N22串联，N21一端接Dr1，作为输出直流电压的一极，另一端与N22一端相连，作为输出直流电压的另一极； N21 and N22 are connected in series, one end of N21 is connected to Dr1 as one pole of the output DC voltage, and the other end is connected to one end of N22 as the other pole of the output DC voltage;
N22另一端接Dr2，作为输出直流电压的一极，Dr2的输出与Dr1的输出相连。 The other end of N22 is connected to Dr2 as one pole of the output DC voltage, and the output of Dr2 is connected with the output of Dr1. the
在图3所示的电路结构中，还绘出了输出滤波电路，包括输出滤波电感L0和输出滤波电容C0，二极管Dr1和Dr2的输出通过L0连接到C0一端， C0与负载并联，另一端与副边线圈N21和N22的连接处相连。 In the circuit structure shown in Figure 3, the output filter circuit is also drawn, including the output filter inductor L0 and the output filter capacitor C0, the outputs of diodes Dr1 and Dr2 are connected to one end of C0 through L0, C0 is connected in parallel with the load, and the other end is connected to The junctions of the secondary coils N21 and N22 are connected. the
图3所示的移相全桥变换器工作原理如下： The working principle of the phase-shifted full-bridge converter shown in Figure 3 is as follows:
Q11～Q41控制信号分别控制Q11～Q41的导通和关断时间，Q11、Q41导通时，Q11、N1和Q41形成回路；Q21、Q31导通时，Q31、N1和Q21形成回路，在MOS开关管导通时，输入的PFC母线电压通过原边线圈N1变换至副边线圈，并经输出滤波电路整流滤波后输出负载所需的稳定电压，并使电感储能；在MOS开关管关断时，储存在电感中的能量通过输出二极管释放给负载，从而使负载得到连续而稳定的输出电压，MOS开关管的导通和关断时间通过PWM控制器输出的控制信号控制。当负载改变时，例如，需要将该移相全桥变换器应用于另一工作电压较低的负载时，通过调节PWM控制器输出的控制信号的移相角，即使得控制信号的占空比减小，控制Q11～Q41的导通时间减少，从而使得输出至原边线圈的电压降低，调节副边的输出电压到该负载所需的工作电压。 The control signals of Q11~Q41 respectively control the turn-on and turn-off time of Q11~Q41. When Q11 and Q41 are turned on, Q11, N1 and Q41 form a loop; when Q21 and Q31 are turned on, Q31, N1 and Q21 form a loop. In the MOS When the switch tube is turned on, the input PFC bus voltage is converted to the secondary coil through the primary coil N1, and after being rectified and filtered by the output filter circuit, the stable voltage required by the load is output, and the inductor stores energy; when the MOS switch tube is turned off At this time, the energy stored in the inductor is released to the load through the output diode, so that the load can obtain a continuous and stable output voltage. The turn-on and turn-off time of the MOS switch is controlled by the control signal output by the PWM controller. When the load changes, for example, when the phase-shifted full-bridge converter needs to be applied to another load with a lower operating voltage, by adjusting the phase-shift angle of the control signal output by the PWM controller, that is, the duty cycle of the control signal Decrease, control the conduction time of Q11~Q41 to decrease, so that the voltage output to the primary coil is reduced, and the output voltage of the secondary side is adjusted to the working voltage required by the load. the
移相全桥变换器中，在MOS开关管通断的过程中，需要一定的能量，为了减少变换器的功率损耗，一般采用零电压开关，即MOS开关管工作在零电压点，以降低MOS开关管通断的功率损耗，MOS开关管通断所需的能量主要为变压器原边的漏感以及副边折算到原边的漏感的储能，在超前桥臂工作期间，输出滤波电感折算到原边与原边的漏感串联，由于一般输出滤波电感较大，因而有足够的储能来实现超前桥臂的零电压开关；但在滞后桥臂工作期间，变换器处于整流二极管换流期间，两个整流二极管同时导通将变压器副边钳位在零电位，输出滤波电感就不能折算到原边，这样，给滞后桥臂两端电容充放电的能量只有原边等效电感的储能，由于该电感为变压器漏感，漏感很小，因而，没有足够能量实现滞后桥臂的零电压开关。 In the phase-shifted full-bridge converter, a certain amount of energy is required during the on-off process of the MOS switch tube. In order to reduce the power loss of the converter, zero-voltage switching is generally used, that is, the MOS switch tube works at the zero-voltage point to reduce the MOS switch. The power loss of the switching tube on and off, the energy required for the switching of the MOS switching tube is mainly the leakage inductance of the primary side of the transformer and the energy storage converted from the leakage inductance of the secondary side to the primary side. During the operation of the leading bridge arm, the output filter inductance is converted The leakage inductance to the primary side is connected in series with the primary side. Since the output filter inductance is generally large, there is enough energy storage to realize the zero-voltage switching of the leading bridge arm; but during the operation of the lagging bridge arm, the converter is in the rectifier diode commutation During this period, the two rectifier diodes are turned on at the same time to clamp the secondary side of the transformer at zero potential, and the output filter inductance cannot be converted to the primary side. In this way, the energy for charging and discharging the capacitors at both ends of the lagging bridge arm is only the storage of the equivalent inductance of the primary side. Because the inductance is the leakage inductance of the transformer, the leakage inductance is very small, so there is not enough energy to realize the zero voltage switching of the lagging bridge arm. the
为了实现滞后桥臂的零电压开关，现有技术通过在变换器原边串联一个谐振电感Lr来提高滞后桥臂实现零电压开关时所需的能量。 In order to realize the zero-voltage switching of the lagging bridge arm, in the prior art, a resonant inductor Lr is connected in series on the primary side of the converter to increase the energy required for the lagging bridge arm to realize the zero-voltage switching. the
由上述可见，针对不同负载所需的直流工作电压，输出直流电压调整以及负载响应主要通过DC/DC变换电路来实现，即通过调节DC/DC变换电路中MOS开关管控制信号的移相角(占空比)，改变MOS开关管的通断时间，从而调节输出电压。如果负载所需的直流工作电压较低，则MOS开关管控制信号的占空比也将相应降低，由于变换器的损耗以及效率与MOS开关管的工作频率、占空比、磁芯的材料、设计的技术参数以及原副边线圈绕制工艺等相关，在变换器确定后，磁芯的材料、设计的技术参数以及原副边线圈绕制工艺也就确定了，因而，MOS开关管的工作频率和占空比是影响变换器的损耗以及效率的重要因素，当MOS开关管的工作频率越高，MOS开关管的损耗功率越大；占空比越小，导致原边电流有效值增大，损耗相应增大、效率降低。也就是说，通过改变DC/DC变换电路的占空比来调节输出电压，如果占空比范围较大，在占空比较小时，变换器效率明显下降。 It can be seen from the above that for the DC operating voltage required by different loads, the adjustment of the output DC voltage and the load response are mainly realized by the DC/DC conversion circuit, that is, by adjusting the phase shift angle of the MOS switch control signal in the DC/DC conversion circuit ( Duty cycle), change the on-off time of the MOS switch tube, thereby adjusting the output voltage. If the DC operating voltage required by the load is low, the duty cycle of the MOS switch control signal will also be reduced accordingly, due to the loss and efficiency of the converter and the operating frequency, duty cycle, core material, and The technical parameters of the design and the winding process of the primary and secondary coils are related. After the converter is determined, the material of the magnetic core, the technical parameters of the design, and the winding process of the primary and secondary coils are also determined. Therefore, the work of the MOS switch tube Frequency and duty cycle are important factors affecting the loss and efficiency of the converter. When the operating frequency of the MOS switch is higher, the power loss of the MOS switch is greater; the smaller the duty cycle, the greater the effective value of the primary current. , the loss correspondingly increases and the efficiency decreases. That is to say, the output voltage is adjusted by changing the duty ratio of the DC/DC conversion circuit. If the duty ratio range is large, the converter efficiency will drop significantly when the duty ratio is small. the
对于在原边串联了谐振电感的变换电路来说，由于串联的谐振电感将使得电流反向的时间加长，在电流反向的过程中，变换器次级的两个整流二极管都处于导通状态，导致副边电压为零，使得变换电路的占空比范围缩小，这样，使得变换电路输出的直流电压不能满足不同负载的需要，同时，在占空比较小时，变换器效率下降。 For the conversion circuit with a resonant inductance connected in series on the primary side, the time for the current reversal will be prolonged due to the series resonant inductance. As a result, the secondary side voltage is zero, which reduces the duty cycle range of the conversion circuit, so that the DC voltage output by the conversion circuit cannot meet the needs of different loads. At the same time, when the duty cycle is small, the efficiency of the converter decreases. the
发明内容Contents of the invention
有鉴于此，本发明的一个主要目的在于提供一种AC/DC变换器，在保证负载所需的直流工作电压的同时，提高AC/DC变换器效率、降低损耗。 In view of this, a main purpose of the present invention is to provide an AC/DC converter, which improves the efficiency of the AC/DC converter and reduces losses while ensuring the DC operating voltage required by the load. the
为达到上述目的，本发明提供了一种AC/DC变换器，包括输入电压电磁干扰EMI滤波电路、输出电压滤波电路，该AC/DC变换器还包括：功率因数校正PFC电路、DC/DC变换电路及脉宽调制PWM控制电路，其中， To achieve the above object, the present invention provides an AC/DC converter, including an input voltage electromagnetic interference EMI filter circuit, an output voltage filter circuit, the AC/DC converter also includes: a power factor correction PFC circuit, a DC/DC conversion circuit and pulse width modulation PWM control circuit, wherein,
PFC电路，用于对输入电压EMI滤波电路输出的电压进行功率因数校正，输出PFC母线电压，根据PWM控制电路输出的控制信号，实时调节PFC母线电压； The PFC circuit is used to correct the power factor of the voltage output by the input voltage EMI filter circuit, output the PFC bus voltage, and adjust the PFC bus voltage in real time according to the control signal output by the PWM control circuit;
DC/DC变换电路，用于根据PWM控制电路输出的控制信号，调节电路中互补金属氧化物半导体开关管的占空比，再次对PFC电路输出的实时调节的 PFC母线电压进行调节，并进行直流电压变换，将输入的实时调节的PFC母线电压变换为相应负载所需要的直流稳压电压； The DC/DC conversion circuit is used to adjust the duty cycle of the complementary metal oxide semiconductor switching tube in the circuit according to the control signal output by the PWM control circuit, and then adjust the real-time adjusted PFC bus voltage output by the PFC circuit again, and perform DC Voltage conversion, which converts the input real-time regulated PFC bus voltage into the DC regulated voltage required by the corresponding load;
PWM控制电路，用于根据输出电压滤波电路输出的电压以及负载所需的工作电压，生成同时调节PFC电路和DC/DC变换电路的控制信号，分别控制PFC电路和DC/DC变换电路对输入的电压进行调节。 The PWM control circuit is used to generate control signals for simultaneously adjusting the PFC circuit and the DC/DC conversion circuit according to the output voltage of the output voltage filter circuit and the operating voltage required by the load, and respectively control the input of the PFC circuit and the DC/DC conversion circuit. voltage is regulated. the
所述PFC电路包括：第一二极管～第七二极管、第一电感、第一电阻、第一电容以及第一MOS开关管，其中， The PFC circuit includes: a first diode to a seventh diode, a first inductor, a first resistor, a first capacitor, and a first MOS switch tube, wherein,
第一二极管～第四二极管组成整流电路，用于对输入的交流电压进行整流； The first diode to the fourth diode form a rectification circuit, which is used to rectify the input AC voltage;
第五二极管～第七二极管、第一电感、第一电阻、第一电容以及第一MOS开关管，用于对整流后的交流电压进行功率因数调节；同时，第一MOS开关管的栅极接收PWM控制电路输出的控制信号，调节自身的占空比，对整流后的交流电压进行调整，输出预设值的PFC母线电压。 The fifth diode to the seventh diode, the first inductor, the first resistor, the first capacitor and the first MOS switch tube are used to adjust the power factor of the rectified AC voltage; meanwhile, the first MOS switch tube The gate of the gate receives the control signal output by the PWM control circuit, adjusts its own duty cycle, adjusts the rectified AC voltage, and outputs the PFC bus voltage of the preset value. the
所述DC/DC变换电路包括：移相全桥变换器、PWM控制全桥变换器、对称半桥变换器、半桥三电平DC/DC变换器、级联全桥三电平DC/DC变换器、全桥三电平DC/DC变换器或降压/升压变换器。 The DC/DC conversion circuit includes: a phase-shifted full-bridge converter, a PWM-controlled full-bridge converter, a symmetrical half-bridge converter, a half-bridge three-level DC/DC converter, and a cascaded full-bridge three-level DC/DC converter, full-bridge three-level DC/DC converter or buck/boost converter. the
所述移相全桥变换器包括：超前桥臂、滞后桥臂、原边线圈以及次级侧直流电压输出电路，其中， The phase-shifted full-bridge converter includes: a leading bridge arm, a lagging bridge arm, a primary side coil, and a secondary side DC voltage output circuit, wherein,
超前桥臂，第一端分别与所述PFC电路输出的PFC母线电压的正极以及滞后桥臂的第一端相连，第二端分别与所述PFC母线电压的负极以及滞后桥臂的第二端相连，第三端与原边线圈一端相连，第四端接收来自PWM控制电路的超前桥臂控制信号； The first end of the leading bridge arm is respectively connected to the positive pole of the PFC bus voltage output by the PFC circuit and the first end of the lagging bridge arm, and the second end is respectively connected to the negative pole of the PFC bus voltage and the second end of the lagging bridge arm Connected, the third end is connected to one end of the primary coil, and the fourth end receives the leading bridge arm control signal from the PWM control circuit;
滞后桥臂，第三端与原边线圈另一端相连，第四端接收来自PWM控制电路的滞后桥臂控制信号； The lagging bridge arm, the third end is connected to the other end of the primary coil, and the fourth end receives the lagging bridge arm control signal from the PWM control circuit;
所述超前桥臂控制信号超前所述滞后桥臂控制信号预先设定的相位； The leading bridge arm control signal leads the preset phase of the lagging bridge arm control signal;
次级侧直流电压输出电路，用于将原边线圈变换的直流电压输出至输出电压滤波电路。 The secondary side DC voltage output circuit is used to output the DC voltage transformed by the primary side coil to the output voltage filter circuit. the
所述超前桥臂包括：第二MOS开关管和第三MOS开关管， The advanced bridge arm includes: a second MOS switch tube and a third MOS switch tube,
所述第二MOS开关管的第一极和第二极之间，并联有第八二极管和第二电容，第一极分别与所述PFC母线电压的正极以及滞后桥臂的第一端相连，第二极分别与所述第三MOS开关管的第一极以及原边线圈一端相连，控制极接收来自PWM控制电路的第二MOS开关管控制信号； An eighth diode and a second capacitor are connected in parallel between the first pole and the second pole of the second MOS switch tube, and the first pole is respectively connected to the positive pole of the PFC bus voltage and the first end of the lagging bridge arm connected, the second pole is respectively connected to the first pole of the third MOS switch tube and one end of the primary side coil, and the control pole receives the second MOS switch tube control signal from the PWM control circuit;
所述第三MOS开关管的第一极和第二极之间，并联有第十二极管和第三电容，第二极分别与所述PFC母线电压的负极以及滞后桥臂的第二端相连，控制极接收来自PWM控制电路的第三MOS开关管控制信号； A tenth diode and a third capacitor are connected in parallel between the first pole and the second pole of the third MOS switch tube, and the second pole is respectively connected to the negative pole of the PFC bus voltage and the second end of the lagging bridge arm Connected, the control pole receives the third MOS switch tube control signal from the PWM control circuit;
所述第二MOS开关管控制信号与所述第三MOS开关管控制信号互补。 The second MOS switch control signal is complementary to the third MOS switch control signal. the
所述滞后桥臂包括：第四MOS开关管和第五MOS开关管， The lagging bridge arm includes: a fourth MOS switch tube and a fifth MOS switch tube,
所述第四MOS开关管的第一极和第二极之间，并联有第十一二极管和第四电容，第一极分别与所述PFC母线电压的正极以及第二MOS开关管第一极相连，第二极分别与第五MOS开关管的第一极以及原边线圈另一端相连，控制极接收来自PWM控制电路的第四MOS开关管控制信号， An eleventh diode and a fourth capacitor are connected in parallel between the first pole and the second pole of the fourth MOS switch tube, and the first pole is respectively connected to the positive pole of the PFC bus voltage and the second pole of the second MOS switch tube. One pole is connected, the second pole is respectively connected with the first pole of the fifth MOS switch tube and the other end of the primary side coil, and the control pole receives the control signal of the fourth MOS switch tube from the PWM control circuit,
所述第五MOS开关管的第一极和第二极之间，并联有第十二二极管和第五电容，第二极分别与所述PFC母线电压的负极以及第三MOS开关管第二极相连，控制极接收来自PWM控制电路的第五MOS开关管控制信号， A twelfth diode and a fifth capacitor are connected in parallel between the first pole and the second pole of the fifth MOS switch tube, and the second pole is respectively connected to the negative pole of the PFC bus voltage and the third pole of the third MOS switch tube. The two poles are connected, and the control pole receives the fifth MOS switch control signal from the PWM control circuit,
所述第四MOS开关管控制信号与所述第五MOS开关管控制信号互补。 The fourth MOS switch control signal is complementary to the fifth MOS switch control signal. the
所述PWM控制电路包括PFC控制电路和DC/DC控制电路，其中，所述PFC控制电路为专用芯片，接收输出电压滤波电路的输出，对PFC电路进行控制； The PWM control circuit includes a PFC control circuit and a DC/DC control circuit, wherein the PFC control circuit is a dedicated chip, receives the output of the output voltage filter circuit, and controls the PFC circuit;
所述DC/DC控制电路为数字化控制电路，接收输出电压滤波电路的输出，一路输出控制DC/DC变换电路，另一路输出作为PFC控制电路的给定信号。 The DC/DC control circuit is a digital control circuit, which receives the output of the output voltage filter circuit, one output controls the DC/DC conversion circuit, and the other output serves as a given signal for the PFC control circuit. the
进一步包括PFC控制电路和DC/DC控制电路，其中，所述PFC控制电路为专用芯片，接收PWM控制电路的一路输出，对PFC电路进行控制； It further includes a PFC control circuit and a DC/DC control circuit, wherein the PFC control circuit is a dedicated chip that receives one output of the PWM control circuit to control the PFC circuit;
所述DC/DC控制电路为数字化控制电路，接收PWM控制电路的另一路输出，控制DC/DC变换电路。 The DC/DC control circuit is a digital control circuit, which receives another output of the PWM control circuit and controls the DC/DC conversion circuit. the
进一步包括谐振电感，所述超前桥臂第三端通过所述谐振电感与原边线圈一端相连。 It further includes a resonant inductance, the third end of the leading bridge arm is connected to one end of the primary coil through the resonant inductance. the
由上述的技术方案可见，本发明提供的AC/DC变换器，通过确定负载所需的工作电压低于预先设定的值，对输入的交流电压进行整流滤波，校正整流滤波后的交流电压功率因数，形成功率因数校正PFC母线电压，同时调节PFC母线电压、以及DC/DC变换电路中，对PFC母线电压进行DC/DC变换的互补金属氧化物半导体MOS开关管的占空比进行调节，对DC/DC变换电路输出的电压进行整流滤波，向负载输出。使得输出直流电压调整通过PFC电路以及DC/DC变换电路两级来实现，首先适当降低PFC电路输出的PFC母线电压，从而使得负载工作电压较低时，DC/DC变换电路中的MOS开关管可以工作在效率较高的占空比上，在保证负载所需的直流工作电压的同时，提高了AC/DC变换器在输出低电压时的效率、降低了损耗。 It can be seen from the above technical solution that the AC/DC converter provided by the present invention rectifies and filters the input AC voltage by determining that the operating voltage required by the load is lower than the preset value, and corrects the rectified and filtered AC voltage power Factor, forming a power factor correction PFC bus voltage, while adjusting the PFC bus voltage, and in the DC/DC conversion circuit, the duty cycle of the complementary metal oxide semiconductor MOS switch tube that performs DC/DC conversion on the PFC bus voltage is adjusted. The voltage output by the DC/DC conversion circuit is rectified and filtered, and output to the load. The adjustment of the output DC voltage is realized through two stages of the PFC circuit and the DC/DC conversion circuit. First, the PFC bus voltage output by the PFC circuit is appropriately reduced, so that when the load operating voltage is low, the MOS switch tube in the DC/DC conversion circuit can be Working at a duty cycle with high efficiency, while ensuring the DC operating voltage required by the load, it improves the efficiency of the AC/DC converter when outputting low voltage and reduces the loss. the
附图说明Description of drawings
图1为现有AC/DC变换器的结构示意图； Fig. 1 is the structural representation of existing AC/DC converter;
图2为现有一种常见的PFC电路结构示意图； Fig. 2 is a schematic diagram of an existing common PFC circuit structure;
图3为现有移相全桥变换器电路结构示意图； Fig. 3 is the circuit structural diagram of existing phase-shifting full-bridge converter;
图4为本发明控制AC/DC变换的方法流程示意图； Fig. 4 is the schematic flow chart of the method for controlling AC/DC conversion of the present invention;
图5为本发明AC/DC变换器结构示意图； Fig. 5 is the structure diagram of AC/DC converter of the present invention;
图6为本发明AC/DC变换器另一结构示意图； Fig. 6 is another structural schematic diagram of AC/DC converter of the present invention;
图7为本发明AC/DC变换器第三结构示意图； 7 is a schematic diagram of the third structure of the AC/DC converter of the present invention;
图8为本发明AC/DC变换器具体电路结构示意图。 Fig. 8 is a schematic diagram of the specific circuit structure of the AC/DC converter of the present invention. the
具体实施方式Detailed ways
为使本发明的目的、技术方案和优点更加清楚，下面将结合附图及具体实施例对本发明作进一步地详细描述。 In order to make the purpose, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. the
本发明提供的AC/DC变换器，通过对输入的PFC母线电压以及MOS开关管占空比调节相结合的方法，在负载所需直流电压较低时，使输入的PFC母线电压降低，从而可以使MOS开关管的占空比适当提高，这样，既 保证了负载所需的直流工作电压，也提高了AC/DC变换器效率、降低了损耗。 The AC/DC converter provided by the present invention reduces the input PFC bus voltage when the DC voltage required by the load is low by adjusting the input PFC bus voltage and the duty cycle of the MOS switch tube, thereby enabling Properly increase the duty cycle of the MOS switch tube, thus not only ensuring the DC operating voltage required by the load, but also improving the efficiency of the AC/DC converter and reducing losses. the
理论上来说，通过调节控制信号的移相角(占空比)来调节MOS开关管通断时间，当占空比达到理论上的0.5时，变换器的功率损耗以及效率达到最佳值，实际应用中，由于在满足变换器设计的变压器匝数比选择上等方面存在一些误差，实际的占空比都在0.5以下。本发明实施例中，通过对输入的PFC母线电压进行调节，提高MOS开关管工作的占空比，从而提高变换器效率、降低变换器损耗。 Theoretically speaking, the on-off time of the MOS switch is adjusted by adjusting the phase shift angle (duty cycle) of the control signal. When the duty cycle reaches the theoretical value of 0.5, the power loss and efficiency of the converter reach the optimum value. In the application, due to some errors in the selection of the transformer turns ratio that meets the converter design, the actual duty cycle is below 0.5. In the embodiment of the present invention, by adjusting the input PFC bus voltage, the duty cycle of the MOS switch tube is increased, thereby improving the efficiency of the converter and reducing the loss of the converter. the
图4为本发明控制AC/DC变换的方法流程示意图，参见图4，该流程包括： Fig. 4 is a schematic flow diagram of the method for controlling AC/DC conversion in the present invention, referring to Fig. 4, the flow includes:
步骤401，对输入的交流电压进行整流滤波；
本步骤中，对输入的交流电压进行整流滤波，例如，全桥、π型等整流滤波，以滤除交流电压包含的谐波和通过电网传输的谐波。 In this step, the input AC voltage is rectified and filtered, for example, full-bridge, π-type rectified and filtered, to filter out harmonics included in the AC voltage and harmonics transmitted through the power grid. the
步骤402，校正整流滤波后的交流电压功率因数，形成PFC母线电压，根据负载所需的工作电压同时调节PFC母线电压、以及调节对PFC母线电压进行DC/DC变换的MOS开关管的占空比；
本步骤中，对整流滤波后的交流电压进行PFC处理，用以提高变换器的功率因数，满足国际有关技术标准关于谐波的技术要求，减小对电网的谐波污染，从而也提高变换器效率，然后，对形成的PFC母线电压进行两级降压变换，即当负载所需的工作电压低于预先设定的值时，首先根据负载所需的工作电压降低PFC母线电压，接下来再在DC/DC变换中，调节MOS开关管的占空比，将经过DC/DC变换输出的电压调节到负载的工作电压。 In this step, PFC processing is performed on the rectified and filtered AC voltage to improve the power factor of the converter, meet the technical requirements of relevant international technical standards on harmonics, reduce the harmonic pollution to the power grid, and thereby improve the converter. Efficiency, then, perform two-stage step-down conversion on the formed PFC bus voltage, that is, when the operating voltage required by the load is lower than the preset value, first reduce the PFC bus voltage according to the operating voltage required by the load, and then In the DC/DC conversion, the duty ratio of the MOS switch tube is adjusted, and the output voltage after the DC/DC conversion is adjusted to the working voltage of the load. the
实际应用中，降低PFC母线电压可以采用改变电路中MOS开关管的占空比来实现，PWM控制器根据输入的负载工作电压，如果确定需要进行两级电压调节时，例如，如果负载工作电压降低到预先设定值以下，表明通过单独调节DC/DC变换电路中MOS开关管的占空比(该占空比值小)将引起较大的功率损耗以及较低的效率，则根据负载工作电压，按照预先设定的策 略确定两级电压调节中MOS开关管的占空比，通过两级调节，使得电路综合的占空比增大，避免进行一级电压调节时占空比过小引起的功耗增大以及效率降低。 In practical applications, reducing the PFC bus voltage can be achieved by changing the duty cycle of the MOS switch in the circuit. The PWM controller is based on the input load operating voltage. If it is determined that two-stage voltage regulation is required, for example, if the load operating voltage is reduced Below the preset value, it means that by separately adjusting the duty cycle of the MOS switch tube in the DC/DC conversion circuit (the duty cycle value is small) will cause greater power loss and lower efficiency, then according to the load operating voltage, Determine the duty cycle of the MOS switch tube in the two-stage voltage regulation according to the preset strategy. Through the two-stage regulation, the duty cycle of the integrated circuit is increased to avoid the problem caused by the too small duty cycle of the first-stage voltage regulation. Increased power consumption and reduced efficiency. the
举例来说，对于通信电源，由于对EMC和功率因数指标的要求越来越高，而AC/DC变换器单相输出电压范围一般为90VDC～264VDC，DC/DC变换器用于在全输入电压范围内实现全范围输出电压的要求。本实施例中，依据工程经验，可以将PFC母线电压稳定在420VDC，在要求输出电压为低电压，例如，48VDC，以及通信电源模块最低输出电压为42VDC的情况下，根据输入电压范围、输出电压范围、变压器匝数比、变换电路的功率曲线等因素的考虑，可以在第一级变换中，将PFC母线电压降为380VDC。这样，避免了单纯依靠增大DC/DC变换器中MOS开关管控制信号之间的移相角导致的占空比减小，使得变换器原边电流有效值增大，从而导致损耗增加，变换器效率降低，通过将输入DC/DC变换器的PFC母线电压进行微降，从而可以减小控制信号之间的移相角，提高变换器的占空比，使得原边电流有效值减小，在输出低电压时仍能保持较高的效率以及较低的损耗。 For example, for communication power supplies, due to the increasingly high requirements for EMC and power factor indicators, the single-phase output voltage range of AC/DC converters is generally 90VDC ~ 264VDC, and DC/DC converters are used in the full input voltage range within the full range of output voltage requirements. In this embodiment, based on engineering experience, the PFC bus voltage can be stabilized at 420VDC. When the output voltage is required to be low, for example, 48VDC, and the minimum output voltage of the communication power supply module is 42VDC, according to the input voltage range, output voltage Considering factors such as the scope, the turns ratio of the transformer, and the power curve of the conversion circuit, the PFC bus voltage can be reduced to 380VDC in the first-stage conversion. In this way, it avoids the reduction of the duty cycle caused by simply increasing the phase shift angle between the control signals of the MOS switch tubes in the DC/DC converter, which increases the RMS value of the primary side current of the converter, which leads to an increase in loss. The efficiency of the inverter is reduced. By slightly reducing the PFC bus voltage input to the DC/DC converter, the phase shift angle between the control signals can be reduced, the duty cycle of the converter can be increased, and the effective value of the primary current is reduced. It can still maintain high efficiency and low loss when outputting low voltage. the
实际应用中，可以通过输出电压或输出电流来同时调节PFC母线电压以及MOS开关管的占空比，使得变换器MOS开关管占空比尽可能工作在最大占空比附近来提高变换器效率。调节PFC母线电压包括调节PFC母线基准电压、以及调节PFC母线电压的反馈值，可以通过数字、模拟以及数字模拟同时对PFC母线电压进行调节。关于对PFC母线电压进行调节的较佳效率点的范围，与实际技术指标要求相关，需要多次测试后确定。例如，如果较佳效率点的范围较宽，将会导致PFC母线电压范围宽，这样，如果PFC母线电压过低，可能导致在输入电压高到一定值时整流二极管整流后的电压高于PFC母线电压值，使得整流桥整流后的电压直接给PFC母线电容充电，导致变换电路的功率因数恶化。 In practical applications, the PFC bus voltage and the duty cycle of the MOS switch can be adjusted at the same time through the output voltage or output current, so that the duty cycle of the converter MOS switch can be as close as possible to the maximum duty cycle to improve the efficiency of the converter. Regulating the PFC bus voltage includes adjusting the PFC bus reference voltage and adjusting the feedback value of the PFC bus voltage, and the PFC bus voltage can be adjusted simultaneously through digital, analog and digital simulation. The range of the optimal efficiency point for regulating the PFC bus voltage is related to the actual technical index requirements and needs to be determined after multiple tests. For example, if the range of the best efficiency point is wide, it will lead to a wide range of PFC bus voltage. In this way, if the PFC bus voltage is too low, it may cause the rectified voltage of the rectifier diode to be higher than the PFC bus voltage when the input voltage is high to a certain value. The voltage value makes the voltage rectified by the rectifier bridge directly charge the PFC bus capacitor, which leads to the deterioration of the power factor of the conversion circuit. the
本实施例中，为了进一步减少MOS开关管的损耗功率，还可以对MOS开关管的工作频率进行调节，例如，通过输出电压或输出电流同时调节MOS 开关管工作频率、MOS开关管占空比和PFC母线电压，使得MOS开关管工作频率工作在效率最高的频段内，使MOS开关管工作频率稳定在变换器效率最高点附近，以此来拓宽变换器效率最高点的范围，同时使得变换器MOS开关管占空比尽可能工作在最大占空比附近，以提高变换器效率，减少变换器损耗，优化变换器的热设计。 In this embodiment, in order to further reduce the power loss of the MOS switch tube, the operating frequency of the MOS switch tube can also be adjusted, for example, the operating frequency of the MOS switch tube, the duty cycle of the MOS switch tube and the The PFC bus voltage makes the operating frequency of the MOS switching tube work in the frequency band with the highest efficiency, and stabilizes the operating frequency of the MOS switching tube near the highest efficiency point of the converter, so as to broaden the range of the highest efficiency point of the converter and at the same time make the converter MOS The duty ratio of the switching tube should be as close to the maximum duty ratio as possible to improve the efficiency of the converter, reduce the loss of the converter, and optimize the thermal design of the converter. the
步骤403，对DC/DC变换输出的电压进行整流滤波，向负载输出。
至此，该流程结束。 So far, the process ends. the
图5为本发明AC/DC变换器结构示意图，参见图5，该AC/DC变换器包括：输入电压EMI滤波电路、PFC电路、DC/DC变换电路、PWM控制电路以及输出电压滤波电路，其中， Fig. 5 is a structural schematic diagram of the AC/DC converter of the present invention, referring to Fig. 5, the AC/DC converter includes: an input voltage EMI filter circuit, a PFC circuit, a DC/DC conversion circuit, a PWM control circuit and an output voltage filter circuit, wherein ,
输入电压EMI滤波电路，用于对输入的交流电压进行整流滤波，以滤除交流电压包含的谐波和通过电网传输的谐波，并输出至PFC电路； The input voltage EMI filter circuit is used to rectify and filter the input AC voltage to filter out the harmonics contained in the AC voltage and the harmonics transmitted through the power grid, and output to the PFC circuit;
PFC电路，用于对输入电压EMI滤波电路输出的电压进行功率因数校正，形成PFC母线电压，根据PWM控制电路输出的控制信号，将PFC母线电压调节到预设值； The PFC circuit is used to correct the power factor of the voltage output by the input voltage EMI filter circuit to form the PFC bus voltage, and adjust the PFC bus voltage to a preset value according to the control signal output by the PWM control circuit;
预设值可以根据工程经验以及AC/DC变换器的效率、功耗要求等确定。例如，对于较高负载要求的高工作电压，预设值可以为420VDC，对于较轻负载要求的低工作电压，预设值可以为380VDC。 The preset value may be determined according to engineering experience, efficiency and power consumption requirements of the AC/DC converter, and the like. For example, for a high working voltage required by a higher load, the preset value can be 420VDC, and for a low working voltage required by a lighter load, the preset value can be 380VDC. the
DC/DC变换电路，用于对PFC电路输出的PFC母线电压，根据PWM控制电路输出的控制信号，通过电路中MOS开关管的通断再次进行调节，并进行直流电压变换，将输入的PFC母线电压变换为相应负载所需要的直流稳压电压； The DC/DC conversion circuit is used to adjust the PFC bus voltage output by the PFC circuit, according to the control signal output by the PWM control circuit, through the on-off of the MOS switch in the circuit to adjust again, and perform DC voltage conversion to convert the input PFC bus The voltage is transformed into the DC regulated voltage required by the corresponding load;
输出电压滤波电路，用于对DC/DC变换电路输出的电压进行滤波，以进一步提高输出的负载所需要的直流稳压电压的稳定性； The output voltage filter circuit is used to filter the voltage output by the DC/DC conversion circuit to further improve the stability of the DC stabilized voltage required by the output load;
PWM控制电路，用于根据输出电压滤波电路输出的电压，生成控制信号，分别控制PFC电路和DC/DC变换电路对输入的电压进行调节。 The PWM control circuit is used to generate a control signal according to the voltage output by the output voltage filter circuit, and respectively control the PFC circuit and the DC/DC conversion circuit to adjust the input voltage. the
图6为本发明AC/DC变换器另一结构示意图，参见图6，与图5不同 的是，图5中的PWM控制电路在图6中为PFC控制电路和DC/DC控制电路，其中，PFC控制电路采用专用芯片，接收输出电压滤波电路的输出，对FPC电路进行控制，DC/DC控制电路采用数字化控制电路，接收输出电压滤波电路的输出，控制DC/DC变换电路以及PFC控制电路，利用双环控制技术，一路输出直接控制DC/DC变换电路，另一路作为PFC控制电路的给定信号。 Fig. 6 is another schematic structural diagram of the AC/DC converter of the present invention, referring to Fig. 6, different from Fig. 5, the PWM control circuit in Fig. 5 is a PFC control circuit and a DC/DC control circuit in Fig. 6, wherein, The PFC control circuit adopts a dedicated chip, receives the output of the output voltage filter circuit, and controls the FPC circuit. The DC/DC control circuit adopts a digital control circuit, receives the output of the output voltage filter circuit, and controls the DC/DC conversion circuit and the PFC control circuit. Using double-loop control technology, one output directly controls the DC/DC conversion circuit, and the other is used as a given signal for the PFC control circuit. the
图7为本发明AC/DC变换器第三结构示意图，参见图7，与图5不同的是，还包括PFC控制电路和DC/DC控制电路，其中，PFC控制电路分别与PFC电路和PWM控制电路相连，采用专用芯片，接收PWM控制电路输出，对FPC电路进行控制；DC/DC控制电路分别与DC/DC变换电路和PWM控制电路相连，采用数字化控制电路控制DC/DC变换电路；PWM控制电路利用双环控制技术，一路输出作为DC/DC控制电路的给定信号，另一路输出作为PFC控制电路的给定信号。 Fig. 7 is a schematic diagram of the third structure of the AC/DC converter of the present invention. Referring to Fig. 7, the difference from Fig. 5 is that it also includes a PFC control circuit and a DC/DC control circuit, wherein the PFC control circuit is connected with the PFC circuit and the PWM control circuit respectively. The circuit is connected, and a dedicated chip is used to receive the output of the PWM control circuit to control the FPC circuit; the DC/DC control circuit is connected to the DC/DC conversion circuit and the PWM control circuit respectively, and the digital control circuit is used to control the DC/DC conversion circuit; PWM control The circuit uses double-loop control technology, one output is used as a given signal for the DC/DC control circuit, and the other output is used as a given signal for the PFC control circuit. the
图8为本发明AC/DC变换器具体电路结构示意图，参见图8，该AC/DC变换器包括：PFC电路、DC/DC变换电路超前桥臂、滞后桥臂、原边线圈、次级侧直流电压输出电路以及输出电压滤波电路，其中，PFC电路与图2所示的PFC电路结构相类似，DC/DC变换电路超前桥臂、滞后桥臂、原边线圈、次级侧直流电压输出电路以及输出电压滤波电路与图3所示的移相全桥变换器电路结构相类似，在此不再赘述，不同的是，图8所示AC/DC变换器具体电路结构中，MOS开关管控制极的控制信号，分别来自PWM控制电路根据输出电压滤波电路输出电压生成的控制信号，用以调节PFC母线电压以及MOS开关管占空比，以提高变换器效率、降低功耗。 Figure 8 is a schematic diagram of the specific circuit structure of the AC/DC converter of the present invention, referring to Figure 8, the AC/DC converter includes: a PFC circuit, a DC/DC conversion circuit leading bridge arm, a lagging bridge arm, a primary side coil, and a secondary side DC voltage output circuit and output voltage filter circuit, among them, the PFC circuit is similar to the PFC circuit structure shown in Figure 2, and the DC/DC conversion circuit leads the bridge arm, lags the bridge arm, the primary side coil, and the secondary side DC voltage output circuit And the output voltage filter circuit is similar to the circuit structure of the phase-shifted full-bridge converter shown in Figure 3, and will not be repeated here. The difference is that in the specific circuit structure of the AC/DC converter shown in Figure 8, the MOS switch control The control signals of the poles come from the control signals generated by the PWM control circuit according to the output voltage of the output voltage filter circuit to adjust the PFC bus voltage and the duty cycle of the MOS switch to improve the efficiency of the converter and reduce power consumption. the
由上述实施例可见，本发明实施例的AC/DC变换器，通过对输入的交流电压进行整流滤波，校正整流滤波后的交流电压功率因数，形成PFC母线电压，根据负载所需的工作电压同时调节PFC母线电压、以及调节对PFC母线电压进行DC/DC变换的MOS开关管的占空比，然后对DC/DC变换输出的电压进行整流滤波，向负载输出。输出直流电压调整以及负载响应通过 PFC电路以及DC/DC变换电路来实现，调节PFC电路中MOS开关管的占空比，适当降低PFC电路输出的PFC母线电压，从而使得负载工作电压较低时，DC/DC变换电路中的MOS开关管可以工作在效率较高的占空比上，在保证负载所需的直流工作电压的同时，提高了AC/DC变换器在输出低电压时的效率、又能满足输入功率因数指标的要求，降低损耗，有利于变换电路功耗和效率设计的优化，具有较强的工程实用价值。 It can be seen from the above embodiments that the AC/DC converter of the embodiment of the present invention rectifies and filters the input AC voltage, corrects the power factor of the rectified and filtered AC voltage, forms the PFC bus voltage, and simultaneously Adjust the PFC bus voltage and adjust the duty ratio of the MOS switching tube that performs DC/DC conversion on the PFC bus voltage, and then rectify and filter the voltage output by the DC/DC conversion, and output it to the load. The output DC voltage adjustment and load response are realized through the PFC circuit and the DC/DC conversion circuit. The duty ratio of the MOS switch in the PFC circuit is adjusted, and the PFC bus voltage output by the PFC circuit is appropriately reduced, so that when the load operating voltage is low, The MOS switch tube in the DC/DC conversion circuit can work at a higher efficiency duty cycle, while ensuring the DC operating voltage required by the load, it improves the efficiency of the AC/DC converter when outputting low voltage, and It can meet the requirements of the input power factor index, reduce the loss, and is beneficial to the optimization of the power consumption and efficiency design of the conversion circuit, and has strong engineering practical value. the
以上举较佳实施例，对本发明的目的、技术方案和优点进行了进一步详细说明，所应理解的是，以上所述仅为本发明的较佳实施例而已，并不用以限制本发明，凡在本发明的精神和原则之内，所作的任何修改、等同替换、改进等，均应包含在本发明的保护范围之内。 The preferred embodiments above are used to further describe the purpose, technical solutions and advantages of the present invention in detail. It should be understood that the above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Within the spirit and principles of the present invention, any modifications, equivalent replacements, improvements, etc., shall be included within the protection scope of the present invention. the
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| CN101702581A (en)* | 2009-12-09 | 2010-05-05 | 杨戴核 | Home-use 2000w constant voltage and constant frequency regulator |
| JP5644125B2 (en)* | 2010-02-03 | 2014-12-24 | 富士電機株式会社 | Starting method of DC-DC conversion circuit |
| CN102218583B (en)* | 2010-04-16 | 2013-10-16 | 深圳市佳士科技股份有限公司 | Inverter welding machine major loop with PFC (Power Factor Correction) function |
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| CN102457174A (en)* | 2010-10-26 | 2012-05-16 | 中兴通讯股份有限公司 | Power factor correction (PFC) circuit and control method |
| US8441810B2 (en)* | 2010-11-09 | 2013-05-14 | Flextronics Ap, Llc | Cascade power system architecture |
| CN102033188B (en)* | 2010-11-25 | 2013-01-02 | 中国电器科学研究院 | Real-time diagnostic method for open circuit fault of phase-shifted full bridge converter |
| CN102710157B (en) | 2011-03-28 | 2015-04-01 | 光宝电子(广州)有限公司 | Power factor correction boost converter |
| CN102820003B (en)* | 2011-06-09 | 2015-06-03 | 四川柏狮光电技术有限公司 | Intelligent power supply system of high power light emitting diode (LED) display screen module |
| CN102324778A (en)* | 2011-09-30 | 2012-01-18 | 云南电力试验研究院(集团)有限公司 | High-efficiency energy-saving charger |
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| CN102801329B (en)* | 2012-08-09 | 2015-05-13 | 矽力杰半导体技术(杭州)有限公司 | High-efficiency and low-loss AC/DC (Alternating Current/Direct Current) power supply circuit and control method thereof |
| TWI474593B (en)* | 2012-09-06 | 2015-02-21 | Fsp Technology Inc | Power supply apparatus with power factor correction and pulse width modulation mechanism and method thereof |
| US9124194B2 (en)* | 2013-06-03 | 2015-09-01 | Infineon Technologies Austria Ag | Methods and systems for a full-bridge voltage converting device |
| CN103746560B (en)* | 2013-12-16 | 2017-03-22 | 联合汽车电子有限公司 | Control circuit of phase-shifted full-bridge DC/DC converter |
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- 2009
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