阅读说明：本技术 一种电励磁双凸极直流发电机控制系统及其控制方法 (Control system and control method for electro-magnetic doubly salient direct-current generator ) 是由 陈香玲 梅永强 李方 于 2021-09-29 设计创作，主要内容包括：本发明提供了一种电磁励双凸极直流发电机控制系统及其控制方法,其中,控制系统包括双凸极直流发电机和发电机控制器GCU；所述发电电流检测电路、发电电压检测电路和励磁电流检测电路分别输出的发电电流信号IP、发电电压信号VP和励磁电流信号IF一路均与所述MCU连接,另一路分别与发电电流比较电路、电压比较电路和励磁电流比较电路连接；所述逻辑保护驱动电路与所述MCU连接,所述逻辑保护驱动电路的输出端与所述励磁开关连接；即本发明不仅省去了三相永磁励磁机和外部辅助电源,同时励磁主电路采用半桥结构,相比全桥电路,主电路结构更加简单可靠,同时降低硬件成本。(The invention provides an electromagnetic excitation double salient pole direct current generator control system and a control method thereof, wherein the control system comprises a double salient pole direct current generator and a generator controller GCU; one path of a generating current signal IP, a generating voltage signal VP and an exciting current signal IF output by the generating current detection circuit, the generating voltage detection circuit and the exciting current detection circuit respectively is connected with the MCU, and the other path of the generating current signal IP, the generating voltage signal VP and the exciting current signal IF is connected with a generating current comparison circuit, a voltage comparison circuit and an exciting current comparison circuit respectively; the logic protection driving circuit is connected with the MCU, and the output end of the logic protection driving circuit is connected with the excitation switch; the three-phase permanent magnet exciter and the external auxiliary power supply are omitted, and the main exciting circuit adopts a half-bridge structure, so that compared with a full-bridge circuit, the main circuit structure is simpler and more reliable, and the hardware cost is reduced.)

1. A control system of an electro-magnetic doubly salient direct current generator is characterized by comprising a doubly salient direct current generator and a generator controller GCU, wherein the direct current generator and the controller GCU are of an integrated structure;

the double salient pole direct current generator comprises a direct current generator and a rectifying circuit; the direct current generator is a non-magnetic steel double-salient-pole generator, and the rectifying circuit is a three-phase half-wave rectifying circuit or a three-phase full-bridge rectifying circuit;

the GCU comprises an MCU, an excitation main circuit, a logic protection driving circuit, a generating current detection circuit, a generating voltage detection circuit, an excitation current detection circuit, a generator rotating speed detection circuit, a generator temperature detection circuit, a generating current comparison circuit, a voltage comparison circuit and an excitation current comparison circuit;

one path of a generating current signal IP, a generating voltage signal VP and an exciting current signal IF output by the generating current detection circuit, the generating voltage detection circuit and the exciting current detection circuit respectively is connected with the MCU, and the other path of the generating current signal IP, the generating voltage signal VP and the exciting current signal IF is connected with a generating current comparison circuit, a voltage comparison circuit and an exciting current comparison circuit respectively;

the generator rotating speed detection circuit and the generator temperature detection circuit are both connected with the MCU;

the logic protection driving circuit is connected with the MCU, and the output end of the logic protection driving circuit is connected with the excitation switch;

the logic protection driving circuit comprises an AND gate I, a trigger, an AND gate II and a phase inverter; and the output pin 4 of the AND gate I is connected with the pin R of the trigger, the pin Q of the trigger and the MCU output PWM are respectively connected with the pin 2 and the pin 1 of the phase inverter, the pin 3 of the AND gate II is connected with the pin 1 of the phase inverter, and the pin 2 of the phase inverter is connected with the excitation switch.

2. The control system of an electrically excited doubly salient dc generator according to claim 1, wherein the generated current signal IP, the generated voltage signal VP and the exciting current signal IF output by the generated current detection circuit, the generated voltage detection circuit and the exciting current detection circuit respectively send the signals IP-OV, VP-OV and IF-OV compared and output by the generated current comparison circuit, the voltage comparison circuit and the exciting current comparison circuit to the and gate i at the same time, when a fault signal occurs, the and gate i outputs a low level, the trigger outputs a low level and blocks the output signal, and outputs a high level after passing through the and gate ii and the inverter, and the exciting switch is closed; and when the fault signal MCU _ RST is recovered, the MCU resets the trigger and outputs an excitation switch driving signal.

3. The control system of an electrically excited doubly salient direct current generator of claim 1, wherein said main excitation circuit comprises an excitation winding, a diode D1, an excitation switch Q1 and a current sensor; the diode D1 is connected with the excitation switch Q1, the current sensor is connected with the excitation winding, the positive end of the excitation winding is connected with the output end VDC + of the double-salient direct-current generator, the negative end of the excitation winding is connected with the excitation switch Q1, and the current sensor is arranged between the negative end of the excitation winding and the excitation switch to detect excitation current.

4. The control system of an electrically excited doubly salient direct current generator according to claim 1, wherein said generator controller GCU further comprises a field-suppression control circuit, said field-suppression control circuit comprising a field-suppression resistor R1 and a field-suppression switch Q3, said field-suppression resistor R1 being connected at one end to said field-suppression switch Q1 and at the other end to said field-suppression switch Q3, said field-suppression switch Q3 being connected to VDC +.

5. The control system of an electrically excited doubly salient direct current generator of claim 1, wherein said over-current comparison circuit comprises a first comparator IC and a first resistor; the current signal output by the generating current detection circuit is connected with the reverse input end of the first comparator IC, the comparison current setting threshold value formed by the voltage division of the first resistor is connected with the same-direction input end of the first comparator IC, and the output end of the first comparator IC is connected with the input end of the logic protection driving circuit.

6. The control system of an electrically excited doubly salient direct current generator of claim 1, wherein said overvoltage comparison circuit comprises a second comparator IC and a second resistor; the voltage signal output by the generating voltage detection circuit is connected with the reverse input end of the second comparator IC, the comparison voltage setting threshold value formed by dividing voltage of the second resistor is connected with the same-direction input end of the second comparator IC, and the output end of the second comparator IC is connected with the input end of the logic protection driving circuit.

7. The control system of an electrically excited doubly salient direct current generator of claim 1, wherein said excitation comparison circuit comprises a third comparator IC and a third resistor; the excitation signal output by the excitation current detection circuit is connected with the reverse input end of a third comparator IC, a comparison excitation current setting threshold value formed by voltage division of a third resistor is connected with the same-direction input end of the third comparator IC, and the output end of the third comparator IC is connected with the input end of a logic protection driving circuit.

8. The control system of an electrically excited doubly salient direct current generator according to claim 1, further comprising a signal conditioning circuit, wherein output ends of the generated current detection circuit, the generated voltage detection circuit, the exciting current detection circuit, the generator speed detection circuit and the generator temperature detection circuit are all connected with the signal conditioning circuit.

9. A control method of an electro-magnetic doubly salient direct-current generator is characterized by comprising the following steps:

the MCU is used for generating power under constant power control, the outer loop is used for generating current increment control, the detected actual generating current is compared with a given target generating current Iref, and the target exciting current iLref (K) is obtained through PID regulation calculation;

the inner ring is used for exciting current increment control, the exciting current detected in real time is compared with the target exciting current ifref (K) obtained by the outer ring PID calculation, the PID output is the PWM control duty ratio through the PID regulation calculation, and the MCU outputs the corresponding PWM wave to control the exciting switch according to the duty ratio.

10. The method for controlling an electrically excited doubly salient direct current generator according to claim 9, wherein the method specifically comprises the following steps:

(1) determining real-time power generation power and target power generation power

Determining real-time generating power according to the real-time vehicle speed and the real-time power consumption, determining the current maximum generating power according to the current power load, and generating power by using the maximum generating power allowed by the generator as the target generating power;

(2) determination of target generation current

Calculating the current target generating current in real time according to the target generating power determined in the step (1) and the current bus voltage;

(3) determination of target excitation current

Performing PID regulation calculation according to the target generating current and the actual generating current determined in the step (2), wherein PID output is the target exciting current;

(4) determination of the duty cycle of a PWM control of the excitation current

Performing PID regulation calculation according to the target exciting current and the actual exciting current determined in the step (3), wherein PID output is PWM control duty ratio;

(5) and the MCU adjusts the PWM control register according to the PWM duty ratio value and outputs a corresponding PWM wave.

Technical Field

The invention relates to the field of direct-current generator control systems, in particular to an electro-magnetic doubly salient direct-current generator control system and a control method thereof.

Background

A control system of a conventional electro-magnetic doubly salient direct-current generator comprises:

firstly, a generator control system can work only by installing an exciter or an auxiliary power supply or installing magnetic steel on a motor rotor.

Secondly, a generator control system excitation main circuit adopts a full-bridge circuit, four switching tubes and a matched driving circuit, and the size of controller hardware is large and the cost is high.

And thirdly, the generator control system rectifies the main circuit, when relevant components of the main excitation circuit are selected, the operating voltage margin of the components is larger, and the maximum operating voltage of the margin is more than 2 times of the actual operating voltage.

The generator control system adopts constant voltage control, the PI control loop adopts a multi-loop (voltage control loop, generating current control loop and exciting current control loop) control method, the control algorithm is complex, the conventional control chip is not easy to meet the requirements, the requirements on the CPU performance are high, and the hardware cost is high.

The direct current generator excitation control circuit has the following defects and shortcomings:

the exciter or the auxiliary power supply requires more space and cost, and is not allowed in space in the case where the electric vehicle is originally short of space, and the exciter or the auxiliary power supply increases the cost of the power generation system.

The generator needs to be provided with magnetic steel, has high requirements on the structure of the motor, high cost and unreliable high-speed operation, and is not easy to operate at high speed.

Secondly, the main excitation circuit needs a full-bridge circuit structure, the circuit is complex, and the hardware cost is high.

The model selection difficulty of the high-voltage component is increased, and the cost of the device is increased.

The generator controller has complex control algorithm, high requirement on hardware and high cost.

Disclosure of Invention

In order to solve the technical problem, the invention provides a novel control system, namely a control method, of an electro-magnetic doubly salient direct-current generator, and the generator does not need to be provided with magnetic steel. When no high-voltage power supply of the battery pack exists, the generator can establish initial exciting current through residual magnetism at a certain rotating speed, and the generator can output voltage until the rated power is finally met for power generation through positive feedback. The high cost brought by the installation of the magnetic steel is reduced, and meanwhile, the motor can reliably run at a high rotating speed (more than 10 thousands of turns) because the magnetic steel is not installed.

The specific technical scheme is as follows: on one hand, the invention provides a control system of a doubly salient direct current generator, which comprises a non-magnetic steel doubly salient direct current generator and a generator controller GCU, wherein the direct current generator and the controller GCU are of an integrated structure.

The double salient pole DC generator comprises a DC generator and a rectifying circuit. The generator is a non-magnetic steel double-salient generator, and the rectifying circuit is a three-phase half-wave rectifying circuit or a three-phase full-bridge rectifying circuit.

The GCU comprises an MCU, an excitation main circuit, a logic protection driving circuit, a generating current detection circuit, a generating voltage detection circuit, an excitation current detection circuit, a generator rotating speed detection circuit, a generator temperature detection circuit, a generating current comparison circuit, a voltage comparison circuit and an excitation current comparison circuit;

one path of a generating current signal IP, a generating voltage signal VP and an exciting current signal IF output by the generating current detection circuit, the generating voltage detection circuit and the exciting current detection circuit respectively is connected with the MCU, and the other path of the generating current signal IP, the generating voltage signal VP and the exciting current signal IF is connected with a generating current comparison circuit, a voltage comparison circuit and an exciting current comparison circuit respectively;

the generator rotating speed detection circuit and the generator temperature detection circuit are both connected with the MCU;

the logic protection driving circuit is connected with the MCU, and the output end of the logic protection driving circuit is connected with the excitation switch;

the logic protection driving circuit comprises an AND gate I, a trigger, an AND gate II and a phase inverter; and the output pin 4 of the AND gate I is connected with the pin R of the trigger, the pin Q of the trigger and the MCU output PWM are respectively connected with the pin 2 and the pin 1 of the phase inverter, the pin 3 of the AND gate II is connected with the pin 1 of the phase inverter, and the pin 2 of the phase inverter is connected with the excitation switch.

Preferably, the generated current detection circuit adopts a shunt resistor or a Hall current sensor to output current of the generator, and after the current detection conditioning circuit performs amplification and filtering processing, the current is sent to the MCU for algorithm control processing on one hand and sent to the current comparison circuit for logic protection processing on the other hand;

the generating voltage detection circuit divides the voltage VDC + at the output end of the generator through a resistor, isolates an optocoupler, and then performs amplification and filtering processing through a signal conditioning circuit, wherein the amplifying and filtering processing is transmitted to the MCU for algorithm control processing on one hand and is transmitted to a voltage comparison circuit for logic protection processing on the other hand;

the excitation current detection circuit adopts a shunt resistor or a Hall current sensor to amplify and filter the output current IF of the generator excitation winding through a signal conditioning circuit, and then the amplified and filtered output current IF is sent to the MCU for algorithm control processing on one hand and sent to an excitation comparison circuit for logic protection processing on the other hand;

the generator rotating speed detection circuit uses a rotating speed sensor, is arranged at the shaft end of the generator and detects the rotating speed of the generator in real time. After filtering processing is carried out on the output signal of the rotating speed sensor, the output signal is sent to the MCU for control processing;

the generator temperature detection circuit uses a temperature sensor PT100, is arranged in a generator winding and detects the temperature of the generator in real time, and output signals of the temperature sensor are amplified and filtered by a signal conditioning circuit and then are sent to an MCU (microprogrammed control unit) for control processing;

preferably, the generating current signal IP, the generating voltage signal VP and the exciting current signal IF respectively output by the generating current detecting circuit, the generating voltage detecting circuit and the exciting current detecting circuit are respectively used for sending signals IP-OV, VP-OV and IF-OV which are compared and output by the generating current comparing circuit, the voltage comparing circuit and the exciting current comparing circuit to the and gate i, when a fault signal occurs, the and gate i outputs a low level, the trigger outputs a low level and blocks the output signal, the trigger outputs a high level after passing through the and gate ii and the inverter, and the exciting switch is closed; and when the fault signal MCU _ RST is recovered, the MCU resets the trigger and outputs an excitation switch driving signal.

Preferably, the excitation main circuit comprises an excitation winding, a diode D1, an excitation switch Q1 and a current sensor; the diode D1 is connected with the excitation switch Q1, the current sensor is connected with the excitation winding, the positive end of the excitation winding is connected with the output end VDC + of the double-salient direct-current generator, the negative end of the excitation winding is connected with the excitation switch Q1, and the current sensor is arranged between the negative end of the excitation winding and the excitation switch to detect excitation current.

Preferably, the generator controller GCU further includes a field suppression control circuit, the field suppression control circuit includes a field suppression resistor R1 and a field suppression switch Q3, one end of the field suppression resistor R1 is connected to the excitation switch Q1, the other end is connected to the field suppression switch Q3, and the field suppression switch Q3 is connected to VDC +.

Preferably, the generator controller GCU further comprises an over-current comparison circuit, the over-current comparison circuit comprising a first comparator IC and a first resistor; the current signal output by the generating current detection circuit is connected with the reverse input end of the first comparator IC, the comparison voltage setting threshold value formed by dividing voltage of the first resistor is connected with the same-direction input end of the first comparator IC, and the output end of the first comparator IC is connected with the input end of the logic protection driving circuit.

Preferably, the generator controller GCU further comprises an overvoltage comparison circuit, the overvoltage comparison circuit comprising a second comparator IC and a second resistor; the voltage signal output by the generating voltage detection circuit is connected with the reverse input end of the second comparator IC, the comparison voltage setting threshold value formed by dividing voltage of the second resistor is connected with the same-direction input end of the second comparator IC, and the output end of the second comparator IC is connected with the input end of the logic protection driving circuit.

Preferably, the generator controller GCU further includes an excitation comparison circuit including a third comparator IC and a third resistor; an excitation signal output by the excitation current detection circuit is connected with the reverse input end of a third comparator IC, a comparison voltage setting threshold value formed by dividing voltage of a third resistor is connected with the same-direction input end of the third comparator IC, and the output end of the third comparator IC is connected with the input end of a logic protection driving circuit.

Preferably, the power generation device further comprises a signal conditioning circuit, and output ends of the generated current detection circuit, the generated voltage detection circuit, the exciting current detection circuit, the generator rotating speed detection circuit and the generator temperature detection circuit are connected with the signal conditioning circuit.

On the other hand, the invention provides a control method of a double salient pole direct current generator, which comprises the following steps:

the MCU is used for generating power under constant power control, the outer loop is used for generating current increment control, the detected actual generating current is compared with a given target generating current Iref, and the target exciting current iLref (K) is obtained through PID regulation calculation;

the inner ring is used for exciting current increment control, the exciting current detected in real time is compared with the target exciting current ifref (K) obtained by the outer ring PID calculation, the PID output is the PWM control duty ratio through the PID regulation calculation, and the MCU outputs the corresponding PWM wave to control the exciting switch according to the duty ratio.

Preferably, the control method specifically includes the steps of:

(1) determining real-time power generation power and target power generation power

Determining real-time generating power according to the real-time vehicle speed and the real-time power consumption, determining the current maximum generating power according to the current power load, and generating power by using the maximum generating power allowed by the generator as the target generating power;

(2) determination of target generation current

Calculating the current target generating current in real time according to the target generating power determined in the step (1) and the current bus voltage;

(3) determination of target excitation current

Performing PID regulation calculation according to the target generating current and the actual generating current determined in the step (2), wherein PID output is the target exciting current;

(4) determination of the duty cycle of a PWM control of the excitation current

Performing PID regulation calculation according to the target exciting current and the actual exciting current determined in the step (3), wherein PID output is PWM control duty ratio;

(5) and the MCU adjusts the PWM control register according to the PWM duty ratio value and outputs a corresponding PWM wave.

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

1. the invention is based on a novel electric excitation double salient pole direct current generator system, and the generator does not need to be provided with magnetic steel. When no high-voltage power supply of the battery pack exists, the generator can establish initial exciting current through residual magnetism at a certain rotating speed, and the generator can output voltage until the rated power is finally met for power generation through positive feedback. The high cost brought by the installation of the magnetic steel is reduced, and meanwhile, the motor can reliably run at a high rotating speed (more than 10 thousands of turns) because the magnetic steel is not installed.

2. The invention adopts the exciter or the auxiliary power supply to work in the early stage, uses the doubly salient DC generator to output high-voltage direct high-voltage excitation, and has the defects that the main excitation circuit only adopts a full-bridge circuit structure and the like.

The invention has the advantages that the excitation main circuit adopts an asymmetric half-bridge circuit, and can meet the requirement of stable excitation current regulation. An exciter and an external auxiliary power supply are omitted, meanwhile, a main excitation circuit does not need a full-bridge circuit and can also adopt the full-bridge circuit, and the main circuit structure is simpler and more flexible; the motor and the circuit structure are simplified, and the hardware cost is reduced.

3. The logic protection driving circuit provided by the invention can ensure that the generator controller immediately responds to the situation that the generating voltage, the generating current, the exciting current, the generator temperature, the generator rotating speed and the like exceed the design range limit value at any time of the generating system, thereby protecting the generating system to reliably work. The related parts of the power generation system are accurately protected, the working voltage of the rectifier device and the excitation main circuit device is greatly reduced, the model selection difficulty of the devices is reduced, and the cost is reduced.

4. The generator controller adopts constant-power constant-current control, the PI control loop adopts a double-closed-loop (generating current control loop and exciting current control loop) incremental PI control method, the control algorithm is simplified, the dynamic response performance is better under the condition of ensuring the system stability, and the cost is reduced to a certain degree.

5. The double-salient-pole direct current generator is free of magnetic steel, so that the double-salient-pole direct current generator is very suitable for being used in high-speed occasions, and has very high application value in direct current power generation systems of airplanes, vehicles, ships, wind power generation and the like.

Drawings

FIG. 1 is a schematic diagram of an electro-magnetic doubly salient DC power generation control system provided by the invention;

FIG. 2 is a schematic diagram of a logic protection driving circuit according to the present invention;

FIG. 3 is a schematic diagram of a main circuit of the excitation circuit provided by the present invention;

FIG. 4 is a flow chart of an electro-magnetic doubly salient DC power generation control method provided by the invention;

FIG. 5 is a schematic diagram of a Microprocessor Chip (MCU) control logic according to the present invention.

The reference numbers are as follows:

1-AND gate I; 2-a flip-flop; 3-AND gate II; a 4-inverter.

Detailed Description

The drawings are for illustrative purposes only and are not to be construed as limiting the patent; for the purpose of better illustrating the embodiments, certain features of the drawings may be omitted, enlarged or reduced, and do not represent the size of an actual product; it will be understood by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted. Illustrative examples will be described in detail herein.

As shown in fig. 1, the present invention provides a doubly salient dc generator control system, which includes a non-magnetic steel doubly salient dc generator and a generator controller GCU, and the dc generator and the controller GCU are integrated.

The double salient pole DC generator comprises a DC generator and a rectifying circuit. The generator is a non-magnetic steel double-salient generator, and the rectifying circuit is a three-phase half-wave rectifying circuit or a three-phase full-bridge rectifying circuit.

The GCU comprises an MCU, an excitation main circuit, a logic protection driving circuit, a generating current detection circuit, a generating voltage detection circuit, an exciting current detection circuit, a generator rotating speed detection circuit, a generator temperature detection circuit, a generating current comparison circuit, a voltage comparison circuit and an exciting current comparison circuit;

the generated voltage VP, the generated current IP and the exciting current IF are sent to the MCU for software control on one hand, and are sent to the fault protection circuit for logic comparison and then sent to the exciting switch to control the exciting current with the PWM signal output by the MCU for power generation power control on the other hand.

One path of a generating current signal IP, a generating voltage signal VP and an exciting current signal IF output by the generating current detection circuit, the generating voltage detection circuit and the exciting current detection circuit respectively is connected with the MCU, and the other path of the generating current signal IP, the generating voltage signal VP and the exciting current signal IF is connected with a generating current comparison circuit, a voltage comparison circuit and an exciting current comparison circuit respectively;

the generator rotating speed detection circuit and the generator temperature detection circuit are both connected with the MCU;

specifically, the generated current detection circuit adopts a shunt resistor or a Hall current sensor to amplify and filter the output current of the generator through a signal conditioning circuit, and then the amplified and filtered output current is sent to the MCU for algorithm control processing on one hand and sent to a current comparison circuit for logic protection processing on the other hand;

the generating voltage detection circuit divides voltage VDC + at the output end of the generator through a resistor, and after isolating an optocoupler, the generating voltage detection circuit performs amplification and filtering processing through a signal conditioning circuit, on one hand, the generating voltage detection circuit sends the voltage VDC + to an MCU for algorithm control processing, and on the other hand, the generating voltage detection circuit sends the voltage VDC + to a voltage comparison circuit for logic protection processing;

the excitation current detection circuit adopts a shunt resistor or a Hall current sensor to amplify and filter the output current IF of the generator excitation winding through a signal conditioning circuit, and then the amplified and filtered output current IF is sent to the MCU for algorithm control processing on one hand and sent to an excitation comparison circuit for logic protection processing on the other hand;

the generator rotating speed detection circuit uses a rotating speed sensor, is arranged at the shaft end of the generator and detects the rotating speed of the generator in real time. After filtering processing is carried out on the output signal of the rotating speed sensor, the output signal is sent to the MCU for control processing;

the generator temperature detection circuit uses a temperature sensor PT100, is arranged in a generator winding and detects the temperature of the generator in real time, and output signals of the temperature sensor are amplified and filtered by a signal conditioning circuit and then are sent to an MCU (microprogrammed control unit) for control processing;

the logic protection driving circuit is connected with the MCU, and the output end of the logic protection driving circuit is connected with the excitation switch;

as shown in fig. 2, the logic protection driving circuit provided by the present invention may be a logic programmable device, or may be a separate digital device, and specifically includes an and gate i 1, a flip-flop 2, an and gate ii 3, and an inverter 4; the output pin 4 of the gate I1 is connected with the pin R of the trigger, the pin Q of the trigger 2 and the output PWM of the MCU are respectively connected with the pin 2 and the pin 1 of the phase inverter 4, the pin 3 of the gate II 3 is connected with the pin 1 of the phase inverter 4, and the pin 2 of the phase inverter 4 is connected with the excitation switch.

The generating current signal IP, the generating voltage signal VP and the exciting current signal IF which are respectively output by the generating current detection circuit, the generating voltage detection circuit and the exciting current detection circuit simultaneously send signals IP-OV, VP-OV and IF-OV which are respectively compared and output by the generating current comparison circuit, the voltage comparison circuit and the exciting current comparison circuit to the AND gate I; and when the fault signal MCU _ RST is recovered, the MCU resets the trigger and outputs an excitation switch driving signal.

The hardware protection circuit provided by the invention can ensure that the generator controller immediately responds to the generator system when the generation voltage, the generation current, the exciting current, the generator temperature, the generator rotating speed and the like of the generation system exceed the design range limit value at any time, thereby protecting the generation system to reliably work.

The demagnetization is accurately controlled by a controllable demagnetization circuit. Normally, the current flows through the diode D1 and the switch Q2, when the voltage detection circuit detects the overvoltage of the output of the generator, the logic protects the driving circuit, immediately blocks the output of the driving signal, then opens the switch Q2, closes the switch Q3, quickly releases the energy on the excitation winding, and protects the power generation system from being damaged. The working voltage margins of voltage-resistant components of the rectifier main circuit and the excitation main circuit are greatly reduced, and the device model selection difficulty is reduced.

As shown in fig. 3, the main excitation circuit provided by the invention is in an asymmetric half-bridge structure, and an IGBT single tube or an MOSFET single tube is selected according to different voltage classes. The positive end of the excitation winding is directly connected to the output direct-current voltage VDC + of the generator, and the negative end of the excitation winding is connected with an excitation switch Q1; specifically, the excitation main circuit comprises an excitation winding, a diode D1, an excitation switch Q1 and a current sensor; the diode D1 is connected with the excitation switch Q1, the current sensor is connected with the excitation winding, the positive end of the excitation winding is connected with the output end VDC + of the double-salient direct-current generator, the negative end of the excitation winding is connected with the excitation switch Q1, and the current sensor is arranged between the negative end of the excitation winding and the excitation switch Q1 to detect excitation current.

When the double salient pole direct current power generation system does not have a high-voltage excitation source at a high-voltage end, when a prime motor rotates to drive a generator to operate, direct current voltage output by the electric excitation double salient pole direct current generator in the whole designed rotating speed range can be provided for an initial excitation current of an excitation winding under the action of remanence, and the initial excitation current can finally meet the excitation requirement of power generation of the generator under the action of positive feedback circulation.

Generator control ware GCU still includes the control circuit that goes out magnetism, the control circuit that goes out magnetism includes that the switch that goes out magnetism R1 and switch Q3 that goes out magnetism, switch Q3 that goes out magnetism is controllable switch, and switch Q1 connection is excited to the switch that goes out magnetism R1 one end, and the other end is connected with switch Q3 that goes out magnetism, and switch Q3 goes out magnetism with VDC + is connected.

Wherein, the comparison circuits provided by the invention are respectively an overcurrent comparison circuit, a voltage comparison circuit and an excitation comparison circuit,

specifically, the overcurrent comparison circuit comprises a first comparator IC and a first resistor; the current signal output by the generating current detection circuit is connected with the reverse input end of the first comparator IC, the comparison voltage setting threshold value formed by dividing voltage of the first resistor is connected with the same-direction input end of the first comparator IC, and the output end of the first comparator IC is connected with the input end of the logic protection driving circuit.

The overvoltage comparison circuit comprises a second comparator IC and a second resistor; the voltage signal output by the generating voltage detection circuit is connected with the reverse input end of the second comparator IC, the comparison voltage setting threshold value formed by dividing voltage of the second resistor is connected with the same-direction input end of the second comparator IC, and the output end of the second comparator IC is connected with the input end of the logic protection driving circuit.

The excitation comparison circuit comprises a third comparator IC and a third resistor; an excitation signal output by the excitation current detection circuit is connected with the reverse input end of a third comparator IC, a comparison voltage setting threshold value formed by dividing voltage of a third resistor is connected with the same-direction input end of the third comparator IC, and the output end of the third comparator IC is connected with the input end of a logic protection driving circuit.

The invention also comprises a signal conditioning circuit, wherein the output ends of the generating current detection circuit, the generating voltage detection circuit, the exciting current detection circuit, the generator rotating speed detection circuit and the generator temperature detection circuit are all connected with the signal conditioning input end, and the current signal, the voltage signal, the exciting signal, the rotating speed signal and the temperature signal which are respectively output by the generating current detection circuit, the generating voltage detection circuit, the exciting current detection circuit, the generator rotating speed detection circuit and the generator temperature detection circuit through sensors are sent to the MCU for algorithm control processing after signal conditioning, amplifying and filtering processing.

As shown in fig. 4 to 5, in another aspect, the present invention provides a method for controlling a doubly salient dc generator, including:

the control method is realized in a Microprocessor Chip (MCU). The invention adopts constant power generation control, the outer loop is generated current increment control, the detected actual generated power (current) is compared with the given target generated power (current) Iref, and the target exciting current iLref (K) is obtained through PID regulation and calculation.

The inner ring is used for exciting current increment control, the exciting current detected in real time is compared with the target exciting current ifref (K) obtained by the outer ring PID calculation, the PID is regulated and calculated through the PID, the PID output is the PWM control duty ratio, and the MCU outputs the corresponding PWM wave controller exciting switch according to the duty ratio.

Specifically, the control method provided by the invention comprises the following steps:

(1) determining real-time power generation power and target power generation power

Determining real-time generating power according to the real-time vehicle speed and the real-time power consumption, determining the current maximum generating power according to the current power load, and generating power by using the maximum generating power allowed by the generator as the target generating power;

the maximum generating power is determined during the design of the generator, the generating power is divided into a plurality of power levels according to different loads during actual use, the current maximum generating power is determined according to the current power utilization load, and the real-time generating power is determined according to the real-time vehicle speed and the real-time power consumption in the vehicle-mounted generating control system. At high speed and when climbing a slope (heavy load), the target generated power is the maximum generated power allowed by the generator to generate power.

(2) Determination of target generation current

Calculating the current target generating current in real time according to the target generating power determined in the step (1) and the current bus voltage;

(3) determination of target excitation current

Performing PID regulation calculation according to the target generating current and the actual generating current determined in the step (2), wherein PID output is the target exciting current;

(4) determination of the duty cycle of a PWM control of the excitation current

Performing PID regulation calculation according to the target exciting current and the actual exciting current determined in the step (3), wherein PID output is PWM control duty ratio;

(5) and the MCU adjusts the PWM control register according to the PWM duty ratio value and outputs a corresponding PWM wave.

The above detailed description is specific to one possible embodiment of the present invention, and the embodiment is not intended to limit the scope of the present invention, and all equivalent implementations or modifications without departing from the scope of the present invention should be included in the technical scope of the present invention.