Summary of the invention
Embodiments of the invention provide a kind of high-voltage direct-current power-supply circuit, carry out direct current power taking, improve the stability of circuit simultaneously to realize current transformer in high-pressure system.
For achieving the above object, The embodiment provides a kind of high-voltage direct-current power-supply circuit, comprising:
High-frequency isolation transformer, current supply circuit, output rectifier diode, fly-wheel diode and the magnetic reset loop of connecting successively, the first MOS transistor and the second MOS transistor;
Described magnetic reset loop is connected in parallel on the primary side of described high-frequency isolation transformer; The high-pressure side of the primary side of described high-frequency isolation transformer is the high-pressure side of described high-voltage direct-current power-supply circuit input; The source electrode of described second MOS transistor is the low-pressure end of described high-voltage direct-current power-supply circuit input;
Described current supply circuit is connected with described first MOS transistor and the second MOS transistor, for providing driving pulse to described first MOS transistor and the second MOS transistor;
The secondary side of described high-frequency isolation transformer connects described output rectifier diode and fly-wheel diode, and described fly-wheel diode two ends are the voltage output end of described high-voltage direct-current power-supply circuit.
High-voltage direct-current power-supply circuit as above, described current supply circuit specifically comprises: start power supply unit, self-powered unit, Pulse Width Control loop;
The output of described startup power supply unit, described self-powered unit is connected with the input in described Pulse Width Control loop respectively; And be also connected with the grid of described first MOS transistor respectively.
High-voltage direct-current power-supply circuit as above, also comprises: the first conducting diode and the first voltage stabilizing didoe;
The output of described startup power supply unit, described self-powered unit is connected with the positive pole of described first conducting diode respectively, and the negative pole of described first conducting diode is connected with the grid of described first MOS transistor;
The positive pole of described first voltage stabilizing didoe is connected with the source electrode of described first MOS transistor; The negative pole of described first voltage stabilizing didoe is connected with the grid of described first MOS transistor.
High-voltage direct-current power-supply circuit as above, described startup power supply unit comprises: power supply transistor, the current-limiting resistance be connected with described power supply transistor, the second voltage stabilizing didoe and charging capacitor;
The positive pole of described second voltage stabilizing didoe is connected with the low-pressure end of described high-voltage direct-current power-supply circuit input; The negative pole of described second voltage stabilizing didoe is connected with the base stage of described power supply transistor; The positive pole of described second voltage stabilizing didoe and the emitter two ends of described power supply transistor form the output of described startup power supply unit, and in parallel with described charging capacitor; The collector electrode of described power supply transistor is connected with the high-pressure side of described high-voltage direct-current power-supply circuit input.
High-voltage direct-current power-supply circuit as above, described self-powered unit comprises: self-powered transformer, the second conducting diode;
On high-pressure side branch road between the high-pressure side that the primary side of described self-powered transformer is arranged on described output rectifier diode and described high-voltage direct-current power-supply circuit output;
The high-pressure side of the secondary side of described self-powered transformer is connected with the positive pole of described second conducting diode, and the negative pole of described second conducting diode and the low-pressure end of described high-voltage direct-current power-supply circuit output form the output of described self-powered unit.
High-voltage direct-current power-supply circuit as above, described Pulse Width Control loop comprises: Pulse Width Control chip and sampling resistor;
The input of described Pulse Width Control chip is the voltage input end in described Pulse Width Control loop; The output of described Pulse Width Control chip is connected with the grid of described second MOS transistor; The sampling input of described Pulse Width Control chip is connected by the source electrode of described sampling resistor with described second MOS transistor.
High-voltage direct-current power-supply circuit as above, described magnetic reset loop comprises: reset capacitance, reset resistor and reset diode;
Described reset capacitance and described reset resistor are connected in parallel rear one end and are connected with the negative pole of described reset diode, and the other end is connected with the high-pressure side of the primary side of described high-frequency isolation transformer; The positive pole of described reset diode is connected with the low-pressure end of the primary side of described high-frequency isolation transformer.
High-voltage direct-current power-supply circuit as above, also comprises: input filter capacitor and output filter capacitor;
Described input filter capacitor is connected in parallel on the input both sides of described high-voltage direct-current power-supply circuit;
Described output filter capacitor is connected in parallel on the output both sides of described high-voltage direct-current power-supply circuit.
The high-voltage direct-current power-supply circuit that the embodiment of the present invention provides, utilize two MOS transistor series connection as the switch driving high-frequency isolation transformer, and these two MOS transistor combine the effect playing series connection dividing potential drop, whole circuit is made to be more suitable for the circuit environment of high-voltage direct-current power taking.
Accompanying drawing explanation
Fig. 1 is the circuit structure schematic diagram of single ended forward circuit of the prior art;
Fig. 2 is an electrical block diagram of high-voltage direct-current power-supply circuit provided by the invention;
Fig. 3 is another electrical block diagram of high-voltage direct-current power-supply circuit provided by the invention;
Fig. 4 is the circuit structure schematic diagram starting power supply unit in current supply circuit provided by the invention;
Fig. 5 is the circuit structure schematic diagram of self-powered unit in current supply circuit provided by the invention;
Fig. 6 is the circuit structure schematic diagram in Pulse Width Control loop in current supply circuit provided by the invention;
Fig. 7 is the circuit structure schematic diagram in magnetic reset loop provided by the invention;
Fig. 8 is the circuit structure schematic diagram of high-voltage direct-current power-supply circuit provided by the invention.
Drawing reference numeral explanation
W-transformer, W1-former limit winding, W2-vice-side winding, W3 reset winding, Q-switching tube, Lf-output inductor, Cf output filter capacitor, Vin-input voltage, Vo output voltage, ilfthe induced current of-Lf, D1-exports rectifier diode, D2-fly-wheel diode, D3-series diode, D4-first conducting diode, D5-first voltage stabilizing didoe, D6-second voltage stabilizing didoe, D7-second conducting diode, D8-reset diode, T1-high-frequency isolation transformer, T2-self-powered transformer, 21-magnetic reset loop, 22-current supply circuit, 221-starts power supply unit, 222-self-powered unit, 223-Pulse Width Control loop, Q1-first MOS transistor, Q2-second MOS transistor, Q3-power supply transistor, R1, R2, R3-current-limiting resistance, R4-sampling resistor, R5-reset resistor, R6, R7-resistance, C1-charging capacitor, C2-reset capacitance, C3-input filter capacitor, C4-output filter capacitor, U1-Pulse Width Control chip.
Embodiment
Fig. 1 is the circuit structure schematic diagram of single ended forward circuit of the prior art.As shown in Figure 1, transformer W has three windings: former limit winding W1, vice-side winding W2 and reset winding W3; Corresponding voltage is respectively Vw1, Vw2and Vw3; The Same Name of Ends of figure orbicular spot indication transformer.D3 is the series diode of reset winding W3, and switching tube Q works by pulse-width modulation (Pulse-Width Modulation, PWM) mode, and D1 exports rectifier diode, and D2 is fly-wheel diode, and terminal voltage is Vrect, Lf is output inductor, ilfbe the induced current of output inductor, Cf is output filter capacitor, Vininput voltage, Voit is output voltage.
As shown in Figure 1, single ended forward circuit of the prior art adopts unlatching and the shutoff of single switching tube Q control transformer W, and the switching tube Q be usually made up of MOS transistor or triode transistor it is withstand voltage usually at below 1000V, cause existing single ended forward circuit and be not suitable in the high pressure electricity getting system of wind electric converter.The high-voltage direct-current power-supply circuit that the embodiment of the present invention provides is on the basis of existing single ended forward circuit, synchronously opened by the MOS transistor of two series connection and realize dividing potential drop of connecting with turning off, make to drop on each MOS transistor pressure drop to diminish, thus be applicable to the high pressure electricity getting system of wind electric converter.And corresponding, the structure of whole high-voltage direct-current power-supply circuit also will make corresponding adjustment.
Embodiment one
Fig. 2 is the electrical block diagram of high-voltage direct-current power-supply circuit provided by the invention, and this circuit can realize in the enterprising horizontal high voltage power taking of the DC bus of wind turbine generator and the voltage be converted into needed for generator set controller.As shown in Figure 2, this high-voltage direct-current power-supply circuit specifically comprises:
High-frequency isolation transformer T1, current supply circuit 22, output rectifier diode D1, sustained diode 2 and magnetic reset loop 21, the first MOS transistor Q1 connected successively and the second MOS transistor Q2;
Magnetic reset loop 21 is connected in parallel on the primary side of high-frequency isolation transformer T1; The high-pressure side that the high-pressure side of the primary side of high-frequency isolation transformer T1 is the power-supply circuit of high-voltage direct-current shown in Fig. 2 input; The source electrode of the second MOS transistor Q2 is the low-pressure end of high-voltage direct-current power-supply circuit input;
Current supply circuit 22 is connected with the first MOS transistor Q1 and the second MOS transistor Q2, for providing driving pulse to the first MOS transistor Q1 and the second MOS transistor Q2;
The secondary side of high-frequency isolation transformer T1 connects output rectifier diode D1 and sustained diode 2, and sustained diode 2 two ends are the voltage output end of high-voltage direct-current power-supply circuit.
As shown in Figure 2, above-mentioned high-voltage direct-current power-supply circuit input terminal voltage is designated as Vin, and output end voltage is designated as Vo.Wherein, above-mentioned magnetic reset loop 21 is identical with the reset winding W3 effect in embodiment illustrated in fig. 1, be mainly used in high-frequency isolation transformer T1 when the first MOS transistor Q1 and the second MOS transistor Q2 synchronously ends, its magnetic energy is eliminated, thus avoid the first MOS transistor Q1 and the second MOS transistor Q2 again synchronous conducting time occur that magnetic energy is saturated.In the present embodiment, the particular circuit configurations for magnetic reset loop 21 is not construed as limiting.
As shown in Figure 2, current supply circuit 22 is for providing driving pulse for the first MOS transistor Q1 and the second MOS transistor Q2.Understandable, if enable high-frequency isolation transformer T1 work, need ensure that the first MOS transistor Q1 and the second MOS transistor Q2 is synchronous conducting and cut-off.In the present embodiment, the particular circuit configurations for current supply circuit 22 is not construed as limiting.
As shown in Figure 2, rectifier diode D1 and sustained diode 2 and its position in FIG with act on identical, do not repeat at this.
Further, as shown in Figure 3, current supply circuit 22 specifically comprises: start power supply unit 221, self-powered unit 222, Pulse Width Control loop 223; Wherein:
The output of startup power supply unit 221, self-powered unit 222 is connected with the input in Pulse Width Control loop 223 respectively; And be also connected with the grid of the first MOS transistor Q1 respectively.
Further, also comprise in embodiment illustrated in fig. 3: the first conducting diode D4 and the first voltage stabilizing didoe D5;
The output of startup power supply unit 221, self-powered unit 222 is connected with the positive pole of the first conducting diode D4 respectively, and the negative pole of the first conducting diode D4 is connected with the grid of the first MOS transistor Q1;
The positive pole of the first voltage stabilizing didoe D5 is connected with the source electrode of the first MOS transistor Q1; The negative pole of the first voltage stabilizing didoe D5 is connected with the grid of the first MOS transistor Q1.
Wherein, start power supply unit 221 in above-mentioned high-voltage direct-current power-supply circuit start-up course for the first MOS transistor Q1 and the second MOS transistor Q2 provides driving pulse; Self-powered unit 222 in the course of work after above-mentioned high-voltage direct-current power-supply circuit starts for the first MOS transistor Q1 and the second MOS transistor Q2 provides driving pulse.As can be seen from Figure 3 service time of the first MOS transistor Q1 and the second MOS transistor Q2 Complete Synchronization, when the second MOS transistor Q2 turns off, the first MOS transistor Q1 is in suspension closed condition.
Further, as shown in Figure 4, for the particular circuit configurations of above-mentioned startup power supply unit 221, comprising: power supply transistor Q3, the current-limiting resistance (comprising R1, R2, R3) be connected with described power supply transistor, the second voltage stabilizing didoe D6 and charging capacitor C1;
The positive pole of the second voltage stabilizing didoe D6 is connected with the low-pressure end of high-voltage direct-current power-supply circuit input; The negative pole of the second voltage stabilizing didoe D6 is connected with the base stage of power supply transistor Q3; The positive pole of the second voltage stabilizing didoe D6 and the emitter two ends of power supply transistor Q3 form the output end vo starting power supply unit 221, and in parallel with charging capacitor C1; The collector electrode of power supply transistor Q3 is connected with the high-pressure side of high-voltage direct-current power-supply circuit input.
Particularly, this startup power supply unit 221 is in high-voltage direct-current power-supply circuit start-up course, utilize plus high-pressure Vin (DC bus-bar voltage as in unit) by current-limiting resistance R1, R2, R3, and as the second voltage stabilizing didoe D6 of 12V, charge to charging capacitor C1 in the loop that power supply transistor Q3 forms, thus provide driving-energy for the Pulse Width Control loop 223 in the first MOS transistor Q1 and Fig. 3, in Fig. 4, output end voltage Vo is clamped at fixed voltage as on 12V by the second voltage-stabiliser tube D6, thus meet the driving demand of the first MOS transistor Q1 and the second MOS transistor Q2 when high-voltage direct-current power-supply circuit starts.
Further, as shown in Figure 5, be the particular circuit configurations of above-mentioned self-powered unit 222, comprise: self-powered transformer T2, the second conducting diode D7.
Shown in composition graphs 8, the primary side of self-powered transformer T2 is arranged on the high-pressure side branch road between output rectifier diode D1 and the high-pressure side of described high-voltage direct-current power-supply circuit output;
The high-pressure side of the secondary side of self-powered transformer T2 is connected with the positive pole of the second conducting diode D7, and the negative pole of the second conducting diode D7 and the low-pressure end of high-voltage direct-current power-supply circuit output form the output of described self-powered unit.
Particularly, this self-powered unit 222, after high-voltage direct-current power-supply circuit starts, utilizes the self-powered transformer T2 added in the output loop of high-voltage direct-current power-supply circuit, constitutes self-powered loop.After high-voltage direct-current power-supply circuit starts, export as 24V direct voltage, self-powered transformer T2 is made to be operated in high frequency flyback state, when the first MOS transistor Q1 and the second MOS transistor Q2 turns off, charged to charging capacitor C1 by self-powered transformer T2, thus provide the energy of next Periodic signal drive first MOS transistor Q1 and the second MOS transistor Q2 for Pulse Width Control loop 223.
Further, as shown in Figure 6, be the particular circuit configurations in above-mentioned Pulse Width Control loop 223, comprise: Pulse Width Control chip U1 and sampling resistor R4;
Pulse Width Control chip U1 can be specifically pulse width modulating chip, as chip UC3823.The voltage input end that the input (high voltage input) of Pulse Width Control chip U1 is Pulse Width Control loop 223; The output of Pulse Width Control chip U1 is connected with the grid of the second MOS transistor Q2; The sampling input of Pulse Width Control chip U1 is connected with the source electrode of the second MOS transistor Q2, for the series current of acquisition stream through the first MOS transistor Q1 and the second MOS transistor Q2 by sampling resistor R4.
Further, as shown in Figure 7, be the particular circuit configurations in above-mentioned magnetic reset loop, comprise: reset capacitance C2, reset resistor R5 and reset diode D8;
Reset capacitance C2 and reset resistor R5 are connected in parallel rear one end and are connected with the negative pole of reset diode D8, and the other end is connected with the high-pressure side of the primary side of high-frequency isolation transformer T1; The positive pole of reset diode D8 is connected with the low-pressure end of the primary side of high-frequency isolation transformer T1.
Fig. 8 is the circuit structure schematic diagram of high-voltage direct-current power-supply circuit provided by the invention, comprises the circuit structure that as above Fig. 2 is extremely embodiment illustrated in fig. 7.
In Fig. 8, the power supply process starting power supply unit 221 and self-powered unit 222 is: when high-voltage direct-current power-supply circuit starts, starting power supply unit 221 is that charging capacitor C1 charges by power supply transistor Q3, thus provides driving-energy for the first MOS transistor Q1 and the second MOS transistor Q2; After high-voltage direct-current power-supply circuit normally starts, self-powered unit 222 starts work, now starts Q3 cut-off in power supply unit 221, no longer charges to charging capacitor C1, but by self-powered unit for Q1 and Q2 continues to provide driving-energy.
Further; as shown in Figure 8; between Pulse Width Control chip U1 and the second MOS transistor Q2, be also in series with a resistance R6, between the first conducting diode D4 and the first MOS transistor Q1 grid, be also in series with a resistance R7, these resistance play the effect of current-limiting protection in circuit.
Further, as shown in Figure 8, input filter capacitor C3 and input filter capacitor C4 is also parallel with respectively, for carrying out filtering to input voltage and output voltage at the input of high-voltage direct-current power-supply circuit and output.
Further, in Fig. 8, the primary side of high-frequency isolation transformer T1 and the coil ratio of secondary side are 20:1, and the primary side of self-powered transformer T2 and the coil ratio of secondary side are 2:1.First MOS transistor Q1 and the second MOS transistor Q2 all can adopt model to be the transistor of 2SK3748.
In concrete practice, test the high-voltage direct-current power-supply circuit that the present embodiment provides, test result is as follows:
Output voltage laod stability: ± 1% (nominal input voltage, output loading changes 10% ~ 100%, the ratio of scope range of the fluctuation of voltage and rated output voltage);
Output ripple: 200mV (gamut input voltage, amount of exports fixed load, the ripple peak-to-peak value of output voltage)
Dynamic response: ± 4.0%/400uS (load, at 50% to 75% Spline smoothing, exports overshoot amplitude and recovery time);
Fully loaded temperature rise: 30 DEG C (system full-load run 10 minutes rear casing temperature and ambient temperature difference).
Above parameters all meets design requirement, can be applied to wind electric converter high voltage dc bus automatic electricity getting and power to control system.
The high-voltage direct-current power-supply circuit that the embodiment of the present invention provides, comprising: high-frequency isolation transformer, current supply circuit, output rectifier diode, fly-wheel diode and the magnetic reset loop of connecting successively, the first MOS transistor and the second MOS transistor; Described magnetic reset loop is connected in parallel on the primary side of described high-frequency isolation transformer; The high-pressure side of the primary side of described high-frequency isolation transformer is the high-pressure side of described high-voltage direct-current power-supply circuit input; The source electrode of described second MOS transistor is the low-pressure end of described high-voltage direct-current power-supply circuit input; Described current supply circuit is connected with described first MOS transistor and the second MOS transistor, for providing driving pulse to described first MOS transistor and the second MOS transistor; The secondary side of described high-frequency isolation transformer connects described output rectifier diode and fly-wheel diode, and described fly-wheel diode two ends are the voltage output end of described high-voltage direct-current power-supply circuit.Scheme described in the present embodiment is by the switching tube of series connection two MOS transistor as driving high-frequency isolation transformer, the reverse voltage of high-frequency isolation transformer when shared applying high voltage (current transformer DC bus-bar voltage) and switching tube turn off, makes Circuits System stablize.Meanwhile, in order to be better that two switching tubes are powered, the present embodiment also sets forth powers and self-powered power supply unit circuit in running, for the normal work of switching tube provides safeguard in circuit start process.
Last it is noted that above each embodiment is only in order to illustrate technical scheme of the present invention, be not intended to limit; Although with reference to foregoing embodiments to invention has been detailed description, those of ordinary skill in the art is to be understood that: it still can be modified to the technical scheme described in foregoing embodiments, or carries out equivalent replacement to wherein some or all of technical characteristic; And these amendments or replacement, do not make the essence of appropriate technical solution depart from the scope of various embodiments of the present invention technical scheme.