阅读说明：本技术 一种电力电子技术实现的取力车载电源 (Power take-off vehicle-mounted power supply realized by power electronic technology ) 是由 何超 王潞钢 姜涛 于 2019-10-14 设计创作，主要内容包括：一种电力电子技术实现的取力车载电源,包括整流二极管、直流电容、逆变电路、控制器和励磁电源；整流二极管接收发电机发出的交流电,将其整流成带脉动的直流电输出给直流电容；直流电容对带脉动的直流电进行滤波处理,得到平直的直流电输出给逆变电路；逆变电路在控制器的控制下,将平直的直流电逆变成稳定的交流电,供负载使用；控制器实时采集各部分的输出,向励磁电源发送励磁电流输出指令,以使发电机发出的交流电电压保持稳定；励磁电源向发电机输出调节后的励磁电流。本发明体积和重量明显减小,提高了控制快速性和管道柔性,安装简单,不需要定期维护。(A power take-off vehicle-mounted power supply realized by power electronic technology comprises a rectifier diode, a direct current capacitor, an inverter circuit, a controller and an excitation power supply; the rectifier diode receives alternating current generated by the generator, rectifies the alternating current into direct current with pulsation and outputs the direct current to the direct current capacitor; the direct current capacitor carries out filtering processing on the direct current with the pulsation to obtain straight direct current and outputs the straight direct current to the inverter circuit; the inverter circuit inverts the straight direct current into stable alternating current for load use under the control of the controller; the controller collects the output of each part in real time and sends an exciting current output instruction to an exciting power supply so as to keep the alternating current voltage sent by the generator stable; the excitation power supply outputs the adjusted excitation current to the generator. The invention has the advantages of obviously reduced volume and weight, improved control rapidity and pipeline flexibility, simple installation and no need of regular maintenance.)

1. The utility model provides a power take-off vehicle power supply that power electronic technology realized which characterized in that: the direct current power supply comprises a rectifier diode, a direct current capacitor, an inverter circuit, a controller and an excitation power supply;

a rectifier diode: receiving alternating current generated by a generator, rectifying the alternating current into direct current with pulsation, and outputting the direct current to a direct current capacitor;

a direct current capacitor: filtering the received direct current with pulsation to obtain straight direct current, and outputting the straight direct current to an inverter circuit;

an inverter circuit: under the control of the controller, the straight direct current is inverted into stable alternating current for load use;

a controller: collecting alternating current voltage sent by a generator, direct current voltage output by a direct current capacitor to an inverter circuit, load current and exciting current output by an exciting power supply to the generator in real time, monitoring the variation trend of the two voltages, and sending an exciting current output instruction to the exciting power supply according to the variation trend so as to keep the alternating current voltage sent by the generator stable; controlling an inverter circuit to invert the straight direct current into stable alternating current;

excitation power supply: and outputting the regulated exciting current to the generator according to an exciting current output instruction sent by the controller.

2. The power take-off vehicle-mounted power supply realized by the power electronic technology according to claim 1, characterized in that: the controller adopts the double closed loop control mode to obtain exciting current output instruction, the double closed loop includes inner loop and outer loop, and wherein the inner loop is exciting current ring, and the outer loop is alternating current voltage ring/direct current voltage ring, and concrete control mode is as follows:

(1) the controller collects alternating current voltage sent by the generator, direct current voltage output to the inverter circuit by the direct current capacitor and exciting current output to the generator by the exciting power supply in real time, carries out PID control on the outer ring according to the alternating current voltage sent by the generator, the direct current voltage output to the inverter circuit by the direct current capacitor and the load current, and outputs an exciting current adjusting instruction to the inner ring;

(2) the controller carries out PI control on the inner ring according to the exciting current adjusting instruction and the real-time exciting current output to the generator by the exciting power supply to obtain a duty ratio instruction of the exciting power supply, and the exciting power supply outputs corresponding exciting current to the generator according to the duty ratio instruction.

3. The power take-off vehicle-mounted power supply realized by the power electronic technology according to claim 2, characterized in that: the controller selects the outer ring as the alternating current voltage ring or the direct current voltage ring according to the load size, and when the outer ring is the alternating current voltage ring, the controller performs PID control on the outer ring according to the alternating current voltage generated by the generator; when the outer ring is a direct current voltage ring, the controller performs PID control on the outer ring according to the direct current voltage output to the inverter circuit by the direct current capacitor.

4. The power-electronic-technology-implemented power take-off vehicle-mounted power supply according to claim 3, characterized in that: the controller selects the mode that the outer ring is an alternating current voltage ring or a direct current voltage ring as follows:

(s1) the controller obtains the load instantaneous power P according to the alternating current voltage and the load current generated by the generator, and the calculation formula is as follows:

P＝ua＊ia+ub＊ib+uc＊ic

the ua, the ub and the uc are three-phase alternating current voltage instantaneous values generated by the generator respectively, and the ia, the ib and the ic are three-phase load current instantaneous values of the load respectively.

(s2) when P is lower than 5% of the total power of the vehicle-mounted power supply, the load is considered to be a low-power load, and the controller selects the outer ring to be the alternating-current voltage ring; when P is not lower than 5% of the total power of the vehicle-mounted power supply, the load is considered to be a high-power load, and the controller selects the outer ring to be the direct-current voltage ring.

5. The power-electronic-technology-implemented power take-off vehicle-mounted power supply according to claim 4, characterized in that: when the load changes, the controller adopts hysteresis control to realize the switching of the outer ring between the alternating current voltage ring and the direct current voltage ring, so that the frequent switching induced jitter is avoided, and the hysteresis control switching method comprises the following steps:

when the load power P is changed from small to large, when the load power P is 5% of the total power of the vehicle-mounted power supply, the alternating current voltage ring is switched to the direct current voltage ring;

when the load power P is reduced from large to small, when P is 6% of the total power of the vehicle-mounted power supply, the direct-current voltage ring is switched to the alternating-current voltage ring.

6. The power-electronic-technology-implemented power take-off vehicle-mounted power supply according to claim 5, characterized in that: when the load changes, the controller adopts following mode to realize the steady switching of outer loop between AC voltage ring and DC voltage ring:

before switching, the integral value of the current working voltage ring PI controller is subjected to the dimension conversion of alternating current-direct current or direct current-alternating current, and then is assigned to the opposite voltage ring PI controller. Therefore, after switching, the PID controller cannot be adjusted in a large range, and the switching stability is ensured.

7. The power take-off vehicle-mounted power supply realized by the power electronic technology according to claim 1, characterized in that: the controller sends three-phase SPWM and third harmonic to the inverter circuit, and the inverter circuit inverts the straight direct current into stable alternating current under the control of the three-phase SPWM and the third harmonic.

8. The power-electronic-technology-implemented power take-off vehicle-mounted power supply according to claim 7, characterized in that: and the controller respectively performs PI control on the three-phase alternating current formed by the inversion of the inverter and then outputs the three-phase alternating current to a load, and the output amplitude limit of the PI control is 5%.

9. The power-electronic-technology-implemented power take-off vehicle-mounted power supply according to claim 7, characterized in that: the controller carries out dead zone compensation on the three-phase SPWM and the third harmonic which are sent to the inverter circuit, and the compensation strategy is as follows:

original signal ＊ compensation factor is compensated signal

The compensation coefficient gradually increases from the zero crossing point to the top point, and gradually decreases from the top point to the zero crossing point, the compensation coefficient at the top point is 1, and the compensation coefficient at the zero crossing point is 1+ dead zone/switching period.

10. The power take-off vehicle-mounted power supply realized by the power electronic technology according to claim 1, characterized in that: the excitation power supply is formed by connecting a bridge circuit and a direct current support capacitor in parallel, the input is 80V direct current power supply, and the bridge circuit is composed of 4 MOS (metal oxide semiconductor) tubes and 4 diodes.

Technical Field

The invention relates to a power take-off vehicle-mounted power supply realized by a power electronic technology, and belongs to the field of vehicle-mounted power supply.

Background

An onboard power supply is a typical military and civilian combination product. On missile launching vehicles and large engineering machinery vehicles, even civil trucks, a 380V high-power three-phase power supply is needed for a 380V high-power three-phase load. The addition of a diesel generator to a vehicle results in increased cost and maintenance complexity, and is an outdated solution. The reasonable mode is that the generator is directly connected to the automobile engine, but a new problem is caused, the rotating speed of the engine is changed rapidly in the process of acceleration and deceleration, the range is wide, the difference is several times, the output voltage and the frequency of the generator are changed several times, and the generator is not acceptable for electrical appliances at all. The output must be provided with a voltage and frequency stabilizing device. The traditional method is that a hydraulic transmission and a hydraulic motor are used for driving a generator, as shown in figure 1, a hydraulic pump is coaxially arranged on the engine and is transmitted to a rear hydraulic motor through a hydraulic oil circuit, and the hydraulic motor drives the generator to generate electricity. The hydraulic motor is provided with a controller, and closed-loop control is performed according to the output voltage, so that the output rotating speed of the hydraulic motor is basically stable, and the stable output voltage is achieved. The problems with this technique are that the volume and weight are large, the flexibility of the pipeline is not sufficient, the installation is complicated, and regular maintenance is required in order to change the oil and prevent the oil leakage.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the power take-off vehicle-mounted power supply overcomes the defects of the prior art, the size and the weight are obviously reduced, the control rapidity and the pipeline flexibility are improved, the installation is simple, and the periodic maintenance is not needed.

The technical solution of the invention is as follows:

a power take-off vehicle-mounted power supply realized by power electronic technology comprises a rectifier diode, a direct current capacitor, an inverter circuit, a controller and an excitation power supply;

a rectifier diode: receiving alternating current generated by a generator, rectifying the alternating current into direct current with pulsation, and outputting the direct current to a direct current capacitor;

a direct current capacitor: filtering the received direct current with pulsation to obtain straight direct current, and outputting the straight direct current to an inverter circuit;

an inverter circuit: under the control of the controller, the straight direct current is inverted into stable alternating current for load use;

a controller: collecting alternating current voltage sent by a generator, direct current voltage output by a direct current capacitor to an inverter circuit, load current and exciting current output by an exciting power supply to the generator in real time, monitoring the variation trend of the two voltages, and sending an exciting current output instruction to the exciting power supply according to the variation trend so as to keep the alternating current voltage sent by the generator stable; controlling an inverter circuit to invert the straight direct current into stable alternating current;

excitation power supply: and outputting the regulated exciting current to the generator according to an exciting current output instruction sent by the controller.

The controller adopts the double closed loop control mode to obtain exciting current output instruction, the double closed loop includes inner loop and outer loop, and wherein the inner loop is exciting current ring, and the outer loop is alternating current voltage ring/direct current voltage ring, and concrete control mode is as follows:

(1) the controller collects alternating current voltage sent by the generator, direct current voltage output to the inverter circuit by the direct current capacitor and exciting current output to the generator by the exciting power supply in real time, carries out PID control on the outer ring according to the alternating current voltage sent by the generator, the direct current voltage output to the inverter circuit by the direct current capacitor and the load current, and outputs an exciting current adjusting instruction to the inner ring;

(2) the controller carries out PI control on the inner ring according to the exciting current adjusting instruction and the real-time exciting current output to the generator by the exciting power supply to obtain a duty ratio instruction of the exciting power supply, and the exciting power supply outputs corresponding exciting current to the generator according to the duty ratio instruction.

The controller selects the outer ring as the alternating current voltage ring or the direct current voltage ring according to the load size, and when the outer ring is the alternating current voltage ring, the controller performs PID control on the outer ring according to the alternating current voltage generated by the generator; when the outer ring is a direct current voltage ring, the controller performs PID control on the outer ring according to the direct current voltage output to the inverter circuit by the direct current capacitor.

The controller selects the mode that the outer ring is an alternating current voltage ring or a direct current voltage ring as follows:

(s1) the controller obtains the load instantaneous power P according to the alternating current voltage and the load current generated by the generator, and the calculation formula is as follows:

P＝ua*ia+ub*ib+uc*ic

the ua, the ub and the uc are three-phase alternating current voltage instantaneous values generated by the generator respectively, and the ia, the ib and the ic are three-phase load current instantaneous values of the load respectively.

(s2) when P is lower than 5% of the total power of the vehicle-mounted power supply, the load is considered to be a low-power load, and the controller selects the outer ring to be the alternating-current voltage ring; when P is not lower than 5% of the total power of the vehicle-mounted power supply, the load is considered to be a high-power load, and the controller selects the outer ring to be the direct-current voltage ring.

When the load changes, the controller adopts hysteresis control to realize the switching of the outer ring between the alternating current voltage ring and the direct current voltage ring, so that the frequent switching induced jitter is avoided, and the hysteresis control switching method comprises the following steps:

when the load power P is changed from small to large, when the load power P is 5% of the total power of the vehicle-mounted power supply, the alternating current voltage ring is switched to the direct current voltage ring;

when the load power P is reduced from large to small, when P is 6% of the total power of the vehicle-mounted power supply, the direct-current voltage ring is switched to the alternating-current voltage ring.

When the load changes, the controller adopts following mode to realize the steady switching of outer loop between AC voltage ring and DC voltage ring:

before switching, the integral value of the current working voltage ring PI controller is subjected to the dimension conversion of alternating current-direct current or direct current-alternating current, and then is assigned to the opposite voltage ring PI controller. Therefore, after switching, the PID controller cannot be adjusted in a large range, and the switching stability is ensured.

The controller sends three-phase SPWM and third harmonic to the inverter circuit, and the inverter circuit inverts the straight direct current into stable alternating current under the control of the three-phase SPWM and the third harmonic.

And the controller respectively performs PI control on the three-phase alternating current formed by the inversion of the inverter and then outputs the three-phase alternating current to a load, and the output amplitude limit of the PI control is 5%.

The controller carries out dead zone compensation on the three-phase SPWM and the third harmonic which are sent to the inverter circuit, and the compensation strategy is as follows:

compensation coefficient of original signal

The compensation coefficient gradually increases from the zero crossing point to the top point, and gradually decreases from the top point to the zero crossing point, the compensation coefficient at the top point is 1, and the compensation coefficient at the zero crossing point is 1+ dead zone/switching period.

The excitation power supply is formed by connecting a bridge circuit and a direct current support capacitor in parallel, the input is 80V direct current power supply, and the bridge circuit is composed of 4 MOS (metal oxide semiconductor) tubes and 4 diodes.

Compared with the prior art, the invention has the following beneficial effects:

(1) the invention applies power electronic equipment, stabilizes output voltage by excitation of the generator and double outer ring control, cancels a hydraulic system, and greatly reduces volume and weight. The output power is also 30KW, and the weight is reduced to 1/2.

(2) Compared with a hydraulic system, the pipeline is realized by adopting the cable, oil change and oil leakage prevention are not needed, the control rapidity and the pipeline flexibility are improved, the installation is simple, and regular maintenance is not needed.

(3) The output of the excitation power supply of the invention does not need to be added with an inductor, because the excitation loop of the generator is a large inductor. The large inductance can cause the response of the exciting current to slow, and the invention applies the bridge circuit, can open the reverse path under the control of the controller to generate the reverse current, thereby reducing the output current rapidly and improving the rapid response capability of the exciting current.

(4) If the outer ring control uses alternating voltage, the lag of the effective value calculation is large, and direct voltage needs to be introduced to form double outer ring control, so that the running rapidity and stability of the vehicle-mounted power supply are improved.

Drawings

FIG. 1 is a schematic diagram of a hydraulic power take-off vehicle power supply;

FIG. 2 is a schematic diagram of a power take-off vehicle power supply implemented by the power electronic technology of the present invention;

FIG. 3 is a schematic diagram of an excitation power supply;

FIG. 4 is a block diagram of dual closed loop control in an embodiment of the present invention;

FIG. 5 is a diagram illustrating dual outer loop handover in an embodiment of the present invention;

FIG. 6 is a schematic diagram of compensation according to an embodiment of the present invention.

Detailed Description

The invention relates to a vehicle-mounted power supply directly connected with an automobile engine. Designed to replace previous hydraulic system solutions. The rotating speed of the automobile engine has a rotating speed range which is several times that of a direct-connected generator, the voltage and the frequency of the direct-connected generator can be changed several times, and the direct-connected generator can not be directly used. On the basis of the excitation inner ring, a double outer ring control of a direct current voltage and an alternating current voltage is particularly used.

The invention adopts quick regulation excitation to stabilize voltage and adopts AC-DC-AC inversion to stabilize frequency. Adjusting the excitation requires a double closed loop to control the excitation current. The inner ring is an excitation current ring, and the outer ring is an alternating current voltage ring (or a direct current voltage ring). The ac voltage detection effective value is slow and is not suitable for use as a fast excitation system. The direct current voltage is introduced as a feedback value of an outer ring, and the aim is to stabilize the direct current voltage. Because the front stage of the invention is pure diode rectification, the direct current voltage and the alternating current voltage are in complete corresponding relation, and the aim of stabilizing the direct current voltage is to completely achieve the aim of stabilizing the alternating current voltage. However, when there is no load or the load is smaller, the electricity in the large-capacity dc support capacitor is not consumed by the load, and when the ac voltage drops, the dc voltage cannot be reflected well, resulting in the failure of the regulation, so that the ac voltage outer ring can only be used when the load is light. The onboard power supply needs to be controlled using a double outer loop. The switching of the double outer rings is very important, and if the impact is too large, the airplane can be tripped, particularly when the switching is frequently carried out under light load. The invention adopts a special mechanism to ensure the stable switching of the double outer rings and protect the operation of the quick excitation system.

Specifically, the power take-off vehicle-mounted power supply realized by the power electronic technology of the invention, as shown in fig. 2, includes a rectifier diode, a dc capacitor, an inverter circuit, a controller and an excitation power supply.

A rectifier diode: receiving alternating current generated by a generator, rectifying the alternating current into direct current with pulsation, and outputting the direct current to a direct current capacitor;

a direct current capacitor: filtering the received direct current with pulsation to obtain straight direct current, and outputting the straight direct current to an inverter circuit;

an inverter circuit: under the control of the controller, the straight direct current is inverted into stable alternating current for load use;

a controller: collecting alternating current voltage sent by a generator, direct current voltage output by a direct current capacitor to an inverter circuit, load current and exciting current output by an exciting power supply to the generator in real time, monitoring the variation trend of the two voltages, and sending an exciting current output instruction to the exciting power supply according to the variation trend so as to keep the alternating current voltage sent by the generator stable; controlling an inverter circuit to invert the straight direct current into stable alternating current;

excitation power supply: and outputting the regulated exciting current to the generator according to an exciting current output instruction sent by the controller.

The controller adopts the double closed loop control mode to obtain exciting current output instruction, and the double closed loop includes inner ring and outer loop, and wherein the inner ring is exciting current ring, and the outer loop is alternating current clamping ring/direct current clamping ring, and specific control mode is as follows:

(1) the controller collects alternating current voltage sent by the generator, direct current voltage output to the inverter circuit by the direct current capacitor and exciting current output to the generator by the exciting power supply in real time, carries out PID control on the outer ring according to the alternating current voltage sent by the generator, the direct current voltage output to the inverter circuit by the direct current capacitor and the load current, and outputs an exciting current adjusting instruction to the inner ring;

(2) the controller carries out PI control on the inner ring according to the exciting current adjusting instruction and the real-time exciting current output to the generator by the exciting power supply to obtain a duty ratio instruction of the exciting power supply, and the exciting power supply outputs corresponding exciting current to the generator according to the duty ratio instruction.

The controller selects the outer ring as an alternating current voltage ring or a direct current voltage ring according to the load size:

the controller obtains the load instantaneous power P according to the alternating current voltage and the load current sent by the generator, and the calculation formula is as follows:

P＝ua*ia+ub*ib+uc*ic

the ua, the ub and the uc are three-phase alternating current voltage instantaneous values generated by the generator respectively, and the ia, the ib and the ic are three-phase load current instantaneous values of the load respectively.

When P is lower than 5% of the total power of the vehicle-mounted power supply, the load is considered to be a low-power load, and the controller selects an outer ring as an alternating-current voltage ring; when P is not lower than 5% of the total power of the vehicle-mounted power supply, the load is considered to be a high-power load, and the controller selects the outer ring to be the direct-current voltage ring.

When the outer ring is an alternating current voltage ring, the controller performs PID control on the outer ring according to alternating current voltage generated by the generator; when the outer ring is a direct current voltage ring, the controller performs PID control on the outer ring according to the direct current voltage output to the inverter circuit by the direct current capacitor.

When the load changes, the controller adopts hysteresis control to realize the switching of the outer ring between the alternating current voltage ring and the direct current voltage ring, so that the frequent switching induced jitter is avoided, and the hysteresis control switching method comprises the following steps:

when the load power P is changed from small to large, when the load power P is 5% of the total power of the vehicle-mounted power supply, the alternating current voltage ring is switched to the direct current voltage ring;

when the load power P is reduced from large to small, when P is 6% of the total power of the vehicle-mounted power supply, the direct-current voltage ring is switched to the alternating-current voltage ring.

When the load changes, the controller adopts following mode to realize the steady switching of outer loop between AC voltage ring and DC voltage ring:

before switching, the integral value of the current working voltage ring PI controller is subjected to the dimension conversion of alternating current-direct current or direct current-alternating current, and then is assigned to the opposite voltage ring PI controller. Therefore, after switching, the PID controller cannot be adjusted in a large range, and the switching stability is ensured.

The controller sends three-phase SPWM and third harmonic to the inverter circuit, and the inverter circuit inverts the straight direct current into stable alternating current under the control of the three-phase SPWM and the third harmonic.

The controller respectively performs PI control on three-phase alternating current formed by inversion of the inverter and then outputs the three-phase alternating current to a load, and the output amplitude limit of the PI control is 5%.

The controller carries out dead zone compensation on the three-phase SPWM and the third harmonic which are sent to the inverter circuit, and the compensation strategy is as follows:

compensation coefficient of original signal

The compensation coefficient gradually increases from the zero crossing point to the top point, and gradually decreases from the top point to the zero crossing point, the compensation coefficient at the top point is 1, and the compensation coefficient at the zero crossing point is 1+ dead zone/switching period.

As shown in fig. 3, the excitation power supply is composed of a bridge circuit and a dc support capacitor connected in parallel, the input is 80V dc power supply, and the bridge circuit is composed of 4 MOS transistors and 4 diodes.