CN103444064A - Device and method for DC/DC conversion in the onboard network of a vehicle - Google Patents

Abstract

The invention relates to a conversion device in the onboard network of a vehicle linked on the one hand to a stop-start module (11) comprising a starter-alternator and to a set of super-capacitors (12) and on the other hand to the 14 volt onboard network of the vehicle (13) and to a battery (14). This device comprises at least two differentiated DC/DC converters (20, 21), identical from a hardware and software point of view and disposed in parallel and linked to a supervisor by a communication system, with symmetric wiring at input and output, and means for learning the imbalance in wiring impedance over a predetermined period. The invention also relates to a method for conversion implementing this device.

Description

The apparatus and method of DC/DC conversion in the vehicle onboard power system

Technical field

The present invention relates to the apparatus and method of for example, changing in the onboard power system of vehicle (, automobile).

Background technology

The known a series of solutions of people, they are easy to realize, and can put goods on the market rapidly on the different stage of vehicle hybrid.Allow to reduce significantly in such solution and consume and CO₂discharge.

There is " stop-start " (stop-moving) scheme of two kinds of complementations, or the starter from strengthening, or from alternator-starter.When vehicle stop, the stop-start function kills engine, and then restarts it to noiseless immediately.The starter strengthened allows to realize the stop-start function, in the European NEDC cycle (" New European Driving Cycle (new European driving pattern) "), consumes and reduces by 4 to 6%.Due to the Noninvasive of this system on the vehicle body architecture, can in the very short time, install.Realize that from alternator-starter the stop-start function provides different hybrid power levels, and thereby, provide and gain and reduce discharge on consuming.This alternating current generator_-the starter permission obtains the improvement of efficiency, because the vehicle travelled under some speed cuts off engine, consumes in European NEDC circulation and can reduce 6 to 8%, under busy urban transportation, goes directly 25%, and this one or more vehicle stop time surpasses 35%.This alternator-starter is installed, is replaced traditional alternating current generator, need a small amount of change on the vehicle body architecture.

In addition, there is a kind of embodiment that comprises ultracapacitor, allow to reclaim kinetic energy auxiliary heat force engine when needed when braking.So, as shown in Figure 1, in an embodiment of prior art, DC/DC transducer 10 is connected to stop-start module 11 and theenergy storage module 12 based on ultracapacitor at input, and be connected to 14 volts ofonboard power systems 13 at output, and be connected tobattery 14 by switch 15.A solution doubles power by its high voltage managerial ability like this.At vehicle deceleration, on the stage, it plays electric brake to Thermal Motor, and to change the energy be recovered be electric energy, is stored in theultracapacitor 12 that is suitable for frequent charge/discharge cycle.This electric power can be by means of DC/DC transducer 10, be discharged on 14 volts ofonboard power systems 13, perhaps, by the alternator-starter recycling of stop-start module 11, restart Thermal Motor while with box lunch, using the stop-start function, or help out when requiring high power.It allows to reduce significantly the consumption of Thermal Motor, and the gain obtained in European NEDC circulation is estimated as between 10 to 12%.

So, for example, energy exchange between DC/DC transducer 10 managed floating electrical networks (, 24 volts of voltages of nominal) and 14 volts of vehicle electrical networks.But this DC/DC transducer 10 is for the 2.4kW power setting.It can not respond the power requirement between the 2.4kW to 4.8kW that in development, new vehicle occurs.

The present invention is intended to propose a solution, in the situation that the development time does not urgently allow to redesign the DC/DC transducer, allows the such requirement of response.

Summary of the invention

The present invention relates to the conversion equipment in a kind of onboard power system of vehicle, it is connected to the stop-start module that comprises alternator-starter and bank of super capacitors on the one hand, and be connected on theother hand 14 volts of onboard power systems and the battery of vehicle, it is characterized in that, it comprises at least two the DC/DC transducers being arranged in parallel same from the read fortune of hardware and software viewpoint, described transducer is connected to controller by communication system, at input and output, has symmetrical wiring; With the unbalanced device of periodic process learning wiring impedance definite.

Advantageously, device of the present invention also comprises the device that reinitializes.

Advantageously, the inventive system comprises two DC/DC transducers, each transducer comprises software module, software module receives from controller open/stall by the CAN bus and changes order, voltage setting value, the maximum current set point of carrying and voltage measurement signal and current measurement signal, rear and then hardware module, hardware module comprises two average modules, follow voltage control loop after an average module and follow current control loop after another average module, be connected to the set point computing module, rear and then Switching Power Supply, wherein this software module comprises voltage corrector and electric current corrector.

In an Implementation Modes, the inventive system comprises master controller and two and receive thus shared voltage setting value from transducer, and communicate between them, make input provide the voltage setting value of the transducer of less electric current to carry out self adaptation.Each transducer can comprise several modules:

Carry out current balance type and realize the module of learning phase according to temperature, be connected to:

The estimation block of value delta U=f (delta Ohm),

For the estimation block of the target voltage U_target of each transducer, its receives the U_target initial value that computing module provides, and the value delta U that provides of the estimation block of this value, and wherein adopts following algorithm:

" if lifting " DC/DC1,

(U_target_2=U_tar_init

With

U_target_1=U_tar_init+delta_U)

Otherwise, if " lifting " DC/DC2,

(U_target_1=U_tar_init

With

U_target_2=U_tar_init+delta_U)

Advantageously, it is included in the device that applies voltage bias on the voltage setting value that the DC/DC of less electric current transducer is provided.

Advantageously, the inventive system comprises the degraded mode processing apparatus, and diagnosis redundancy device.

The invention still further relates to the DC/DC conversion method in the onboard power system of the vehicle of implementing said apparatus, comprise the following steps:

Each transducer for example receives the step of shared voltage setting value from control unit or controller by communication system, and

Each transducer carries out the communication steps of the internal information of relevant electric current and internal temperature to another transducer, and

Change the step of the voltage setting value that puts on the DC/DC transducer according to temperature difference.

Advantageously, method of the present invention is included in the step that applies voltage bias on the voltage setting value that the DC/DC of less electric current transducer is provided.

Advantageously, method of the present invention comprises the following steps:

Each transducer is on a cycle of operation, by the electric current that its electric current and another transducer are provided, compare, record average current poor, then when this end cycle, store this difference, in each learning cycle process, from second round, the value of precedence record and the value of state-of-the-art record are averaging, complete this measurement

Record the mean temperature difference between these two transducers on the cycle of operation of same number, carry out " heat is relevant ", can suppress in case of necessity to revise after learning phase,

Apply voltage bias on the voltage setting value of the transducer that less electric current is provided, this biasing is uneven reckoning of wiring impedance of obtaining from learning phase.

The accompanying drawing explanation

Fig. 1 illustrates the device of prior art.

Fig. 2 and 3 illustrates device of the present invention.

Fig. 4 illustrates the distribution of the electric current between two DC/DC transducers that are arranged in parallel.

Fig. 5 illustrates corresponding temperature survey.

Useful life between two DC/DC transducers that Fig. 6 means to be arranged in parallel is about the Pareto curve chart of temperature difference (Δ T ℃).

Fig. 7 illustrates the wiring impedance existed between these two transducers of being arranged in parallel and load.

Fig. 8 illustrates the block diagram of the electric current and voltage adjusting of DC/DC transducer.

Fig. 9 illustrates the software adjustment principle of DC/DC transducer.

Figure 10 illustrates an execution mode of device of the present invention.

Figure 11 and 12 illustrates respectively and is not with according to heat balance strategy of the present invention with the control of heat balance strategy.

Figure 13 A and 13B illustrate respectively the compensation Delta_U (Δ U) according to Delta I (Δ I), and according to two examples of the compensation delta U of Delta Ohm.

Figure 14 illustrates in the Implementation Modes according to device of the present invention, the realization of the compensation of Figure 13 B in a DC/DC transducer.

Embodiment

In device of the present invention, as shown in Figure 2, consider to implement at least two DC/DC transducers in parallel (for example, 12V/24V) power structure of 20 and 21.In this Fig. 2, adopt the Reference numeral utilized on Fig. 1.

Fig. 3 illustrates the circuit diagram of the several DC/DC transducers that are arranged in parallel.Thesetransducers 30 on the one hand, for example, are connected to controller (ECU) 31 by means ofCAN bus 32, and are connected topower supply 33 andload 34 byinterconnect module 35 and 36 on the other hand.

While realizing several DC/DC transducer of configuration in parallel like this, when stepup transformer or reducing transformer receive same set point regulation voltage, the electric current that each DC/DC transducer provides depends on the impedance of output cable.

Need such precision in the situation that make every effort to burning voltage; if make in controller or in each DC/DC transducer and there is no the internal current equilibrium strategy; with regard to the electric current in can not restriction one or another transducer and the risk of no-voltage collapse or voltage imbalance, just can't guarantee the balance of the electric current that provided by different transducers.

The DC/DC transducer be arranged in parallel for each is under cooling identical supposition, and the imbalance of electric current is caused by thermal unbalance between each transducer.The location of known these transducers, its thermal environment and refrigerating mode thereof be all unknown and also identical probability very little, thereby need to stipulate a kind of control strategy to these transducers.

Hereinafter, for simplified characterization, as non-limiting example, consider, transducer DC/DC1 and the DC/DC2 of one group of two parallel connection, and also these transducers have communication device between them, and communicate by letter with controller (ECU) by means of the CAN bus.

Present the temperature difference that records and the relation of the current imbalance between cooling the first and second DC/DC transducers (DC/DC1 and DC/DC2) by same procedure at the curve shown in Figure 4 and 5.Along with passage of time, the difference between current of every ampere is approximately corresponding to the temperature difference of a degree centigrade.Yet the temperature difference (or delta) between these two transducers seriously affects its life-span separately in its life cycle.

On Fig. 6, illustrational Pareto curve chart is estimated the life-span of these two transducers according to its temperature difference (successively for control card, for power card with for whole transducer).From this curve chart, calculate, the useful life of the first transducer DC/DC1 worked during than high 30 ℃ of the second transducer DC/DC2 in mean temperature is short approximately 5 times.Thereby the operation of such DC/DC transducer be arranged in parallel constraint should comprise that purpose is to guarantee its thermally equilibrated algorithm, so as the useful life of optimizing them with make it consistent.

In the situation that two transducers carry out is similar cooling, logically temperature difference is directly proportional to the difference between current recorded, or directly depends on the impedance contrast connected up between load and each DC/DC transducer.So Fig. 7 illustrates wiring impedance R1, R2 and the R3 between these two transducers and load.

In order to realize a kind of like this heat balance of these two DC/DC transducers, the present invention defines a kind of strategy, with the management of the internal temperature according to these two DC/DC transducers electric current separately, distributes, and the electric current that the temperature of known converters provides with it is directly related.Verfolgten Ziele is the temperature difference that is less than determined value (for example, 10 ℃).

For this reason, the present invention proposes to adopt the current balance type strategy, by realize the unbalanced study of wiring impedance between load and each DC/DC transducer in the learning cycle process, with this, between each transducer, manages current balance type, in order to make its life-span consistent.

The present invention allows to consider uneven the reinitializing of learning of wiring impedance in the transducer life equally.

In device of the present invention, consider two DC/DC transducers (DC/DC1 and DC/DC2) same from the read fortune of hardware and software viewpoint, be connected to communication system, for example, special-purpose or public CAN (" Controller Area Network (controller area net ") bus being controlled by outside controller (ECU).Mistake proofing mark (detrompage) allows to determine the configuration of each transducer: thereby they have two different identifiers after identification mistake proofing mark, and distinguished on this communication network.They are controlled by two different frameworks.

Each transducer DC/DC1 and DC/DC2 receive following set point:

ON/OF (open/stop) conversion command,

Voltage setting value U_target,

The maximum current set point I_max_target carried.

The hardware/software interface block diagram that is connected to the DC/DC transducer 39 ofload 48 illustrates on Fig. 8.Software module 40 receives set point ON/OFF, U_target, I_max_target and voltage measurement signal U_meas, current measurement signal I_meas, and pulse-width signal PWM_U and PWM_I are provided.Thehardware module 41 that receives these signals PWM_U and PWM_I comprises twoaverage modules 42 and 43, followcurrent control loop 45 after followingvoltage control loop 44 and another average module after an average module, be connected to setpoint computing module 46, follow afterwards SwitchingPower Supply 47.

Fig. 9 illustrates the Principles of Regulation of thesoftware module 50 of DC/DC transducer.Software voltage corrector 51 receives difference signal U_target-U_meas, and output signal PWM_U.Software electriccurrent corrector 52 receives difference signal I_max_ target-Imeas output signal PWM_I.If regulation voltage, do not apply any restriction to electric current in other words, signal PWM_I equals 100%, regulation output voltage be signal PWM_U.

Hereinafter, in the situation that current balance type does not apply any restriction: I_max_target to electric current > Imeas.

In other words, in following example, the electric current of transducer still is less than the maximum current set point I_max_target that will carry.

In illustrational device of the present invention Implementation Modes, in these two DC/DC transducers, implement electric current/heat balance strategy on Figure 10.Main ECU does not manage the heat balance of these two transducers.It sends unique voltage setting value U target to two transducers, carries out self-balancing when study finishes period.It is Limited Current not.Heat balance strategy by study is implemented symmetrically in each DC/DC transducer.But, according to the self adaptation of the poor voltage setting value carried out of the wiring impedance recorded, be in these two transducers, to provide in the transducer of less electric current to carry out asymmetrically, should make it " lifting ", increase in other words its output current.

By between these DC/DC transducers and main ECU and the processing of the information of transmitting, can realize that equally degraded mode processes (operating in gross power X%) and diagnose redundancy between these two DC/DC transducers.

Figure 11 and 12 allows to make the feature of this execution mode to become significantly, is respectively not to be with and with the control chart of two DC/DC transducers of the parallel connection of heat balance strategy.While there is no heat balance, as shown in figure 11, electric current I 1 and I2 (Itotal=I1+I2) depend on the length difference of the cable between each transducer DC/DC1 and DC/DC2 and load.The asymmetric imbalance that automatically causes electric current of wiring.

When constraint is the degree of regulation of burning voltage and load one side, before any current balance type application of policies, it should determine the transducer that less electric current is provided, and wherein it should " promote " operation, in order to guarantee current balance type, and does not suppress another transducer.

For fear of this current imbalance, the present invention's proposition realizes the unbalanced study of wiring impedance, as shown in figure 12.Thereby, realize a learning phase in each DC/DC converter inside in the cycle of operation at predetermined number, in order to, measure the poor and mean temperature difference of average current between these transducers in these learning cycle processes after, calculate the voltage difference on the voltage setting value that puts on (or putting on asymmetrically two a) DC/DC transducer.

In the situation that two transducer parallel connections, each transducer is by comparing between the electric current that its electric current and the second transducer are flow through, for example the average current in a cycle of operation is poor for record, then when this end cycle, preserves the poor of this electric current I.Carry out this measurement during each learning cycle, from second round, the value of the value of precedence record and state-of-the-art record is averaging.

Obtain mean temperature difference on the cycle of operation at same number between these two transducers equally, carrying out " heat is relevant ", can suppress in case of necessity learning phase correction afterwards.

Finally voltage bias is put on to the voltage setting value of the transducer that less electric current is provided.This biasing is that the wiring impedance imbalance of obtaining from learning phase is calculated out.

In order to reduce delta I, illustrational as Figure 13 A and 13B, apply the compensation biasing on this voltage setting value, it is directly proportional to impedance contrast (gain G), or depends on the look-up table later defined in the feature of obtaining transducer configuration in parallel: Delta U compensation=f (Delta Ω).

Figure 13 A means an example, and wherein voltage compensation biasing Delta U is directly proportional to difference between current delta I.Figure 13 B means an example of look-up table (English is " lookup table "), and it comprises curve chart, and the compensation biasing Delta U that puts on transducer is associated with impedance contrast delta Ω.

This learning phase is realized in each transducer, as shown in figure 14, comprises several modules, in other words:

Carry out current balance type and realize themodule 61 of learning phase according to temperature, be connected to:

Theestimation block 62 of delta U=f (delta Ohm),

The estimation block 63 that is used for the target voltage (U target) of each transducer, the value of the Delta U that the U target initial value that its reception is provided bymodule 64 andmodule 62 provide, and wherein adopt following algorithm:

" if lifting " DC/DC1,

(U_target_2=U_tar_init

With

U_target_1=U_tar_init+delta_U)

Otherwise, if " lifting " DC/DC2,

(U_target_1=U_tar_init

With

U_target_2=U_tar_init+delta_U)

In other words, whentemperature T ℃ 1 temperature T lower than transducer DC/DC2 of transducer DC/DC1 ℃ 2, compensation biasing delta U is added on the voltage setting value U_target_1 of transducer DC/DC1.Whentemperature T ℃ 2 temperature T lower than transducer DC/DC1 of transducer DC/DC2 ℃ 1, compensation biasing delta U is added on the voltage setting value U_target_2 of transducer DC/DC2.

In fact, be to make the coldest transducer DC/DC1 or DC/DC2 " lifting ".

If know in advance the wiring configuration, can meet delta U by the maximum of demarcating after test, can stop this phenomenon to produce.

Can when finishing, stipulate learning phase the predetermined value delta U that will apply equally in case of necessity.So, after this learning phase, this value delta U is applied on the set point of one or the other DC/DC transducer according to its wiring configuration.

Can in the module life process, regulation study reinitialize: when X dormancy period finishes, for example, predesignate after transducer once mounting/dismounting, and/or after in its life, wiring route overturns.

Claims (11)

Translated fromChinese

1.一种车辆的车载电网中的转换装置，一方面连接至包括交流发电机-起动机和超级电容器(12)组的停止-起动模块(11)，而另一方面连接到车辆的14伏车载电网(13)和电池(14)，其特征在于，它包括并联设置的至少两个不同的DC／DC转换器(20，21)，所述转换器从硬件和软件观点看相同且通过通信系统连接至控制器，在输入端和输出端具有对称的布线；和在确定的周期过程中对布线阻抗不平衡进行学习的器件。1. A conversion device in the on-board electrical network of a vehicle, connected on the one hand to a stop-start module (11) comprising an alternator-starter and a supercapacitor (12) bank, and on the other hand to the vehicle's 14 volt On-board electrical network (13) and battery (14), characterized in that it comprises at least two different DC/DC converters (20, 21) arranged in parallel, identical from a hardware and software point of view and communicated The system is connected to a controller, having symmetrical wiring at the input and output; and means for learning the impedance imbalance of the wiring during a defined cycle.2.按照权利要求1的装置，它包括再初始化器件。2. Apparatus according to claim 1, comprising reinitialization means.3.按照权利要求1的装置，它包括两个DC／DC转换器，每个转换器(30)包括软件模块(40)，软件模块通过CAN总线从控制器(31)接收开／停转换命令、电压设定值、要输送的最大电流设定值和电压测量信号和电流测量信号，后跟着硬件模块(41)，硬件模块包括两个均值模块(42和43)，一个均值模块后跟着电压控制回路(44)而另一个均值模块后跟着电流控制回路(45)，连接至设定值计算模块(46)，后跟着开关电源(47)，其中该软件模块(50)包括电压修正器和电流修正器(52)。3. The device according to claim 1, comprising two DC/DC converters, each converter (30) comprising a software module (40), the software module receiving the on/off conversion command from the controller (31) via the CAN bus , the voltage setpoint, the maximum current setpoint to be delivered and the voltage measurement signal and the current measurement signal, followed by a hardware module (41), which includes two averaging modules (42 and 43), one averaging module followed by a voltage Control loop (44) and another averaging module followed by a current control loop (45), connected to a setpoint calculation module (46), followed by a switching power supply (47), wherein the software module (50) includes a voltage corrector and Current modifier (52).4.按照权利要求2的装置，包括主控制器和两个从转换器，由此接收共用的电压设定值，而且它们之间进行通信，使输入提供较少电流的转换器的电压设定值进行自适应。4. Apparatus according to claim 2, comprising a master controller and two slave converters whereby a common voltage setpoint is received and communicated between such that the voltage setpoint of the converter providing less current is input value to adapt.5.按照权利要求1的装置，其中每个转换器都包括几个模块：5. The apparatus according to claim 1, wherein each converter comprises several modules:据温度进行电流平衡并实现学习阶段的模块(61)，连接至：Module (61) for current balancing according to temperature and implementation of the learning phase, connected to:delta U=f(delta Ohm)的估算模块(62)，Estimation module (62) of delta U=f(delta Ohm),用于每个转换器的目标电压(U_target)的估算模块(63)，接收由计算模块(64)提供的U_target初始值和其值估算模块(64)提供的值delta U，而且其中采用如下算法：The estimation module (63) for the target voltage (U_target) of each converter receives the initial value of U_target provided by the calculation module (64) and the value delta U provided by its value estimation module (64), and wherein the following algorithm is used :若“提升”DC／DC1，则If "boost" DC/DC1, then(U_target_2=U_tar_init(U_target_2=U_tar_init和andU_target_1=U_tar_init+delta_U)U_target_1=U_tar_init+delta_U)否则，若“提升”DC／DC2，则Otherwise, if DC/DC2 is "boosted", then(U_target_1=U_tar_init(U_target_1=U_tar_init和andU_target_2=U_tar_init+delta_U)。U_target_2=U_tar_init+delta_U).6.按照权利要求5的装置，它包括在提供较少电流的DC／DC转换器的电压设定值上施加电压偏置的器件。6. Apparatus according to claim 5 including means for applying a voltage bias at the voltage setpoint of the DC/DC converter supplying the less current.7.按照权利要求3的装置，它包括降级方式的处理器件。7. Apparatus according to claim 3, comprising processing means in a degraded mode.8.按照权利要求3的装置，它包括诊断冗余器件。8. Apparatus according to claim 3, comprising diagnostic redundancy means.9.一种实施按照权利要求2的装置的车辆车载电网中的DC／DC转换方法，它包括下列步骤：9. A method of DC/DC conversion in a vehicle electrical system implementing the device according to claim 2, comprising the steps of:在每个转换器中从控制器接收共用的电压设定值的步骤，the step of receiving a common voltage setpoint from the controller in each converter,每个转换器向另一个转换器进行有关电流和内部温度的内部信息通信的步骤，和the step of each converter communicating internal information about current and internal temperature to the other converter, and根据温度差改变施加于DC／DC转换器的电压设定值的步骤。The step of changing the voltage setting value applied to the DC/DC converter according to the temperature difference.10.按照权利要求9的方法，包括在提供较少电流的DC／DC转换器的电压设定值上施加电压偏置的步骤。10. A method according to claim 9, including the step of applying a voltage bias at the voltage setpoint of the DC/DC converter supplying less current.11.按照权利要求10的方法，包括下列步骤：11. The method according to claim 10, comprising the steps of:在每个转换器中通过将其电流和另一个转换器的电流之间进行比较，记录一个运行周期中的平均电流差，接着在该周期结束时存储这个电流差，在每个学习周期中，从第二周期起对先前记录的值与最新记录的值求平均，完成这个测量，In each converter, by comparing its current with the current of the other converter, the average current difference is recorded during an operating cycle, and this current difference is then stored at the end of the cycle. In each learning cycle, This measurement is done by averaging the previously recorded value with the latest recorded value from the second period,在同一数目的运行周期中记录这两个转换器之间的平均温度差，进行热相干，它在学习阶段之后必要时允许抑制修正，The average temperature difference between these two converters is recorded over the same number of operating cycles, thermally coherent, which allows suppression corrections if necessary after the learning phase,在提供较少电流的转换器的电压设定值上施加电压偏置，该偏置是从学习阶段求出的布线阻抗不平衡推算的。A voltage bias is applied to the voltage setpoint of the converter delivering less current, which is extrapolated from the wiring impedance imbalance found during the learning phase.

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