Starting control method of airplane auxiliary power device

Abstract

The invention provides a starting control method of an aircraft auxiliary power device. The aircraft auxiliary power device comprises an APU working state electronic regulator, an APU automatic starter, an APU starting box and an engine starting accessory. The APU starting box is connected with the starting generator; the method comprises the steps that when an APU automatic starter receives an aircraft APU starting instruction, the working time sequence of an engine starting accessory is controlled according to a set program, the APU automatic starter is matched with an APU starting box, and the output power of a starting generator is controlled in a grading mode through armature series resistor voltage reduction starting, full-voltage starting and weak magnetic speed regulation, so that the requirement for starting the engine is met, and the starting efficiency is improved. The purpose of smoothly starting the engine is achieved in a low-power-consumption and quick-starting mode.

Description

Technical Field

[0001] The invention belongs to the technical field of avionics systems, and in particular relates to a starting control method for an aircraft auxiliary power unit. Background Art

[0002] The auxiliary power unit (APU) is a small engine installed on the aircraft that is independent of any external energy source and is self-contained. It is mainly used to provide bleed air for the starting and environmental control systems of the aircraft's main engines, and can provide shaft power for the aircraft's power generation system through the accessory gearbox. During ground maintenance, the aircraft's main engine is not working and does not rely on the support of ground equipment. The APU can provide electricity, gas, hydraulics and other energy to the aircraft, improve the aircraft's self-sufficiency and maintenance security, extend the service life of the main engine, and reduce the aircraft's full life cycle maintenance costs; during flight, when the engine fails in the air, or the power supply or hydraulic system fails, the APU can provide power, hydraulics and other auxiliary energy, and can assist the engine in rapid air starting, improving the aircraft's safety and flight capabilities. There are more than a hundred types of APU products, with power ranging from tens of kilowatts to thousands of kilowatts. They have been widely used in military and civilian aircraft. Therefore, modern large and medium-sized aircraft are equipped with APUs.

[0003] The start control system is an important part of the APU and is the prerequisite and key to ensure the reliable operation of the APU. As the APU is used more and more widely, the requirements for the APU are also getting higher and higher, including usage conditions, start energy consumption, reliability, function, performance, etc. At present, during the start process of the APU, there is a problem of high start impact energy consumption, which directly affects whether the APU can start safely, reliably and quickly, and also directly affects the execution of the expected tasks and plans of military and civilian aircraft.

[0004] With the rapid development of the aviation industry, the APU, as the second power of aircraft, is being used in more and more applications, and the safety and reliability of APU has gradually attracted people's attention. How to reduce the APU startup impact energy consumption as much as possible while ensuring the stable operation of APU and not affecting the service life of APU is of great significance for the safe, reliable and fast start of APU. Summary of the invention

[0005] The present invention provides a starting control method for an auxiliary power unit of an aircraft, which solves the problem of high starting impact energy consumption during the starting process of the auxiliary power unit, and can not only provide low-cost APU power generation for the aircraft, but also further improve the stability of the output DC power supply when the starter generator switches from the starting state to the power generation state after successfully starting the engine.

[0006] The present invention provides a starting control method for an aircraft auxiliary power unit, wherein the aircraft auxiliary power unit comprises: an APU working state electronic regulator, an APU automatic starter, an APU starting box, and an engine starting accessory; the APU starting box is connected to a starter generator; the method comprises:

[0007] When the APU automatic starter receives the aircraft APU start command, it controls the working sequence of the engine starting accessories according to the set program, and cooperates with the APU starting box to use armature series resistance voltage reduction starting, full voltage starting and weak magnetic speed regulation to grade the output power of the starter generator, thereby meeting the needs of starting the engine and achieving the purpose of smoothly starting the engine in a low-power and fast-starting manner.

[0008] Optionally, the APU start command is issued by the aircraft pilot by operating a start button on an APU start control panel.

[0009] Optionally, the APU working state electronic regulator is connected to the APU temperature sensor and the speed sensor;

[0010] The APU working status electronic regulator is used to obtain the APU turbine afterburner gas temperature and the APU rotor speed from the APU temperature sensor and the speed sensor.

[0011] Optionally, the APU working state electronic regulator includes: a sensor simulator, a setter combination, a modulator-demodulator, a discontinuous instruction generator and a check logic circuit;

[0012] The APU working status electronic regulator is used to output the corresponding voltage signal when the APU rotor speed reaches various given speeds, and output the APU parking voltage signal when the APU turbine rear gas temperature reaches the limit temperature and the APU is in various working states and the rotor speed reaches the limit speed. The APU working status electronic regulator compares the electrical signals sent by the APU temperature sensor and the speed sensor with the program signals pre-given by the setter. The difference signal is modulated, demodulated and amplified, and then converted into the command voltage output corresponding to each given speed of the APU by the discontinuous command generator.

[0013] Optionally, the APU working status electronic regulator has a working self-check function, which is used to check the working condition of the internal circuit to ensure that the APU working status electronic regulator works normally before the APU is started, and the APU is started after the self-check is completed.

[0014] Optionally, the APU automatic starter includes: a timer, a relay, a transistor, a diode and a resistor, a capacitor;

[0015] The timer is used to output timing control signals;

[0016] The APU automatic starter is used to convert the voltage signal output by the electronic regulator according to the APU working status through internal diodes and relays, and control the timing by a timer. It then performs logic conversion through internal diodes and relays to output various control signals with different timings, control the operation of various starting accessories of the auxiliary power unit, and deliver voltage to the APU starting box according to the specified time program.

[0017] Optionally, the APU starting box includes: a power regulator, a starting voltage reducing resistor R1, a contactor K1, a contactor K2, a relay K3, a relay K4, and a relay K5; the power regulator includes: a stabilizing coil Ww, a control coil Wk, and a working coil Wg;

[0018] The APU starter box is used to control the operation of the internal relays and contactors after receiving the voltage signal output by the APU automatic starter, so that the internal power regulator controls the starter generator to start in stages;

[0019] The starting voltage-dropping resistor R1, the contactor K1, the working coil Wg and the armature circuit of the starter generator are connected in series, and the starting voltage-dropping resistor R1 is connected to a DC power supply; the contactor K2 is arranged in parallel at both ends of the starting voltage-dropping resistor and the contactor K1;

[0020] The adjustable resistor R4, the control coil Wk, the stabilizing coil Ww and the relay K5 are connected in series, and the adjustable resistor R4 is connected to the DC power supply through the contacts 5 and 6 of the relay K5;

[0021] One side of the contacts 1 and 2 of relay K4 is connected to the stabilizing coil Ww through the contacts 1 and 2 of relay K5, and the other side is connected to the exciting coil Wj of the starter generator;

[0022] One side of contacts 3 and 4 of relay K4 is connected to the regulator, and the other side is connected to the excitation coil Wj of the starter generator.

[0023] Optionally, the APU starter box is specifically used to perform the following steps:

[0024] S1, starting, i.e. at 0s: K1 contactor and K5 relay work, K5 connects the stabilizing coil Ww and control coil Wk of the power regulator; K4 disconnects the power supply circuit from the external voltage regulator to the exciting coil of the starter generator, and connects the power supply circuit from the internal power regulator to the exciting coil of the starter generator, so that the starter generator is excited; at the same time, the APU automatic starter receives power to make the K1 contactor work; connect the armature circuit and working coil Wg of the starter generator, so that the starter generator starts with a series voltage drop resistor, driving the APU rotor to rotate, which is the first stage of starting;

[0025] S2, 2 seconds after starting: APU automatic starter receives power to operate K2 contactor, short-circuit the starting voltage drop resistor, increase the armature current of the starter generator, increase the torque, and increase the APU speed. This is the second stage of starting;

[0026] S3, 8 seconds after starting: APU automatic starter receives a call to activate K3 relay, controlling the input of power regulator. The core of power regulator is a controlled high-power variable resistor, which is connected in series to the power supply circuit of the starter generator excitation coil to achieve weak magnetic speed regulation. At this time, the speed of the starter motor is further increased, and the torque is also increased, thereby driving the APU speed to continue to increase. This is the third stage of starting;

[0027] S4. When the APU speed reaches 55%, the APU automatic starter receives the signal from the APU working status electronic regulator, disconnects the power supply circuit of the APU starting box, the APU starting box stops working, the exciting coil of the starter generator is switched to the external voltage regulator for power supply, and the starter generator ends the motor working state and switches to the generator state.

[0028] The present invention provides a starting control method for an aircraft auxiliary power unit, which has the following advantages:

[0029] 1. Reduce APU startup impact energy consumption

[0030] The APU starting process adopts a three-stage starting design of armature series resistance voltage reduction starting, full voltage starting and weak magnetic speed regulation. Through the timing and program control of the APU related starting equipment, the APU can control the APU working accessories according to the signal instructions received, and then start step by step according to the voltage signal output by the starting equipment until the APU starts successfully. The entire APU starting process will be controlled in real time according to the working conditions of the APU working accessories and the collected working parameters of each stage, thereby effectively reducing the APU starting impact energy consumption.

[0031] 2. Improve the safety and reliability of APU starting control system

[0032] When the APU is started, first, the APU start control system will perform a system self-check. If the system self-check is normal, it will wait for the start command. Otherwise, it will stop for inspection. Then, when the system self-check is normal and the start command is received, the relevant start equipment in the APU start control system starts to work, and the APU will complete the three-level start according to the timing and program control until the APU starts successfully. Secondly, during the start process, the sensors in the APU start control system will collect the temperature, lubricating oil pressure, speed and other parameters of the APU in real time. The above parameters will be fed back to the start equipment, and the start equipment will respond and control in real time according to the feedback of the APU working parameters. During the entire APU start process, a closed-loop system integrating collection, control, execution and feedback is formed, thereby improving the safety and reliability of the APU start control system. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is the cross-link block diagram of the APU starting control system;

[0034] Figure 2 It is the schematic diagram of the starting control;

[0035] Figure 3 It is a schematic diagram of the starting process. DETAILED DESCRIPTION

[0036] The present application is further described in detail below with reference to examples and drawings:

[0037] like Figure 1-3 As shown, the aircraft auxiliary power unit includes: an APU working status electronic regulator, an APU automatic starter, an APU starting box, and engine starting accessories; the APU starting box is connected to the starter generator.

[0038] The present invention discloses a starting control method for an aircraft auxiliary power unit. When the APU automatic starter receives the aircraft APU starting command, it controls the engine starting accessories to work according to the set program, and cooperates with the APU starting box to control the output power of the starting generator in stages, thereby meeting the needs of starting the engine and achieving the purpose of starting the engine smoothly in a low-power and fast-starting manner. It mainly involves the aircraft APU starting command, the APU working state electronic regulator, the APU automatic starter, the APU starting box and the starting generator. The APU starting control system cross-linking block diagram is shown in the attached Figure 1 .

[0039] In the start control method of an aircraft auxiliary power unit, an APU start command is issued by the aircraft pilot by operating a start button on an APU start control panel to control the APU system (APU start control system) to start working.

[0040] The APU working status electronic regulator is used to sense the APU turbine post-gas temperature and APU rotor speed; the APU automatic starter is used to control the working sequence of each APU starting accessory; the APU starting box cooperates with the APU automatic starter to control the output power of the starter generator in stages.

[0041] The APU working status electronic regulator is mainly composed of a sensor simulator, a setter combination, a modulator-demodulator, a discontinuous instruction generator and a check logic circuit.

[0042] The APU working status electronic regulator works together with the APU temperature sensor and speed sensor. When the APU rotor reaches various given speeds (30%, 55%, 70%, 90%, 95%, 108%), it outputs the corresponding voltage signal. When the APU turbine rear gas temperature reaches the limit temperature and the APU is in various working states and the rotor speed reaches the limit speed, it outputs the APU parking voltage signal. The APU working status electronic regulator compares the electrical signals sent by the APU temperature sensor and speed sensor with the program signals pre-given by the setter. The difference signal is modulated, demodulated and amplified, and then converted into a command voltage output corresponding to each given speed of the APU by a discontinuous command generator.

[0043] The APU working status electronic regulator has a working self-check function, which can check the working condition of the internal circuit to ensure that the APU working status electronic regulator works normally before the APU is started. The APU can be started only after the self-check is completed.

[0044] The APU automatic starter is mainly composed of an electronic timer, relays, transistors, diodes, resistors, capacitors, etc. The timer can output four timing control signals of 2s, 4s, 8s, and 30s. The APU automatic starter converts the voltage signal output by the electronic regulator of the APU working state through internal diodes and relays, and controls the timing by the timer. Then, the internal diodes and relays perform logic conversion, and output various control signals with different timings to control the operation of each starting accessory of the auxiliary power unit, and transmit voltage to the APU starting box according to the prescribed time program.

[0045] The APU starter box is composed of a power regulator, a starting voltage drop resistor, a contactor, a relay, a socket and a terminal. When the APU starter box receives the voltage signal output by the APU automatic starter, it controls the operation of the internal relays and contactors, so that the internal power regulator controls the starter generator to start in stages. The composition of the APU starter box and its starting control principle are detailed in the attached Figure 2 .

[0046] The APU starting box includes: a power regulator, a starting voltage reducing resistor R1, a contactor K1, a contactor K2, a relay K3, a relay K4, and a relay K5; the power regulator includes: a stabilizing coil Ww, a control coil Wk, and a working coil Wg;

[0047] The APU starter box is used to control the operation of the internal relays and contactors after receiving the voltage signal output by the APU automatic starter, so that the internal power regulator controls the starter generator to start in stages;

[0048] The starting voltage-dropping resistor R1, the contactor K1, the working coil Wg and the armature circuit of the starter generator are connected in series, and the starting voltage-dropping resistor R1 is connected to a DC power supply; the contactor K2 is arranged in parallel at both ends of the starting voltage-dropping resistor and the contactor K1;

[0049] The adjustable resistor R4, the control coil Wk, the stabilizing coil Ww and the relay K5 are connected in series, and the adjustable resistor R4 is connected to the DC power supply through the contacts 5 and 6 of the relay K5;

[0050] One side of the contacts 1 and 2 of relay K4 is connected to the stabilizing coil Ww through the contacts 1 and 2 of relay K5, and the other side is connected to the exciting coil Wj of the starter generator;

[0051] One side of contacts 3 and 4 of relay K4 is connected to the regulator, and the other side is connected to the excitation coil Wj of the starter generator.

[0052] According to the attached Figure 2 Starting control principle diagram, the specific process of graded starting is as follows:

[0053] 1. Starting, i.e. at 0s: K1 and K5 relays work, and K5 connects the stabilizing coil Ww and control coil Wk of the power regulator. K4 disconnects the power supply circuit from the external voltage regulator to the exciting coil of the starter generator, and connects the power supply circuit from the internal power regulator to the exciting coil of the starter generator, so that the starter generator is excited. At the same time, power comes from the APU automatic starter to make the K1 contactor work. The armature circuit and working coil Wg of the starter generator are connected, so that the starter generator starts with a series voltage drop resistor, driving the APU rotor to rotate. This is the first stage of starting;

[0054] 2. After 2 seconds of starting: the APU automatic starter receives power to operate the K2 contactor, short-circuit the starting voltage drop resistor, increase the armature current of the starter generator, increase the torque, and increase the APU speed. This is the second stage of starting;

[0055] 3. 8 seconds after starting: A power is received from the APU automatic starter to activate the K3 relay and control the power regulator. The core of the power regulator is a controlled high-power variable resistor, namely the excitation voltage-dividing resistor, which is connected in series to the power supply circuit of the excitation coil of the starter generator to achieve weak magnetic speed regulation. At this time, the speed of the starter motor increases further, and the torque also increases, thereby driving the APU speed to continue to increase. This is the third stage of starting;

[0056] 4. When the APU speed reaches 55%, the APU automatic starter receives the signal from the APU working state electronic regulator, disconnects the power supply circuit of the APU starting box, and the APU starting box stops working. At this time, the excitation coil of the starter generator is switched to the external voltage regulator for power supply, and the starter generator ends the motor working state and turns to the generator state.

[0057] Taking a certain aircraft platform as an example, the APU starting control system includes an APU working state electronic regulator, an APU automatic starter, an APU starting box and a starting generator. The entire starting process is as follows: Figure 3 shown.

[0058] Before the APU starts, first turn on the self-test switch of the APU working status electronic regulator on the aircraft. The 27V DC voltage on the aircraft is sent to the working performance internal inspection system through the self-test switch to check the working performance. After the working performance is good, disconnect the self-test switch to start the APU. The self-test mainly checks the temperature detection circuit interface, speed detection circuit interface and lubricating oil pressure detection port. If the self-test fails, the machine needs to be stopped for inspection until the cause of the failure is found.

[0059] When the self-check is successfully completed, the pilot needs to operate the start button on the APU start control panel to issue a start selection command. The start commands include APU ground start, APU cold start, APU false start, and APU air start. When one of the commands is selected for start, the start timer in the APU automatic starter starts working. At 0s, the K1 and K5 relays in the APU start box work, and the K5 relay connects the stabilizing coil Ww and the control coil Wk of the power regulator. The power supply current of the starter generator excitation coil Wj remains relatively stable during the change of the power supply voltage during the start process; the 3 and 4 contacts of the K4 relay are disconnected, disconnecting the power supply circuit from the external voltage regulator to the starter generator excitation coil Wj; the 1 and 2 contacts of the K4 relay are closed, connecting the power supply circuit from the internal power regulator to the starter generator excitation coil Wj, so that the starter generator is excited. At the same time, the APU automatic starter receives power to operate the K1 contactor, and the contacts 1 and 2 of the K1 contactor are closed, connecting the armature circuit and working coil Wg of the starter generator. The starter generator starts by connecting the starting voltage-dropping resistor R1 in series, driving the APU rotor to rotate, completing the first-stage starting of the APU. At 2s, the APU automatic starter receives power to operate the K2 contactor, and the contacts 1 and 2 of the K2 contactor are closed. The starting voltage-dropping resistor R1 is short-circuited, increasing the armature current and torque of the starter generator, increasing the speed of the APU, and completing the second-stage starting of the APU. At 8s, the APU automatic starter receives power to disconnect the contacts 3 and 4 of the K3 relay, and no longer short-circuit the excitation voltage-dividing resistor R5. The resistance value of R5 is controlled by the magnetic field of the working coil Wg, which can be achieved by adjusting the position of the spring adjustment piece of the R5 resistor through the change of the magnetic force generated by the magnetic field of the Wg coil. The current of the armature circuit and the working coil Wg decreases during the APU starting process, the resistance value of the exciting voltage divider resistor R5 increases, and the current of the exciting coil Wj decreases. At this time, the speed of the starter motor increases further, and the torque also increases, thereby driving the APU speed to continue to increase, completing the third stage of the APU starting.

[0060] Exemplarily, the current variation curve of the excitation coil Wj can be adjusted by adjusting the adjustable resistor R4 and the control coil Wk.

[0061] After completing the three-stage start of the APU, if the APU turbine rear gas temperature, lubricating oil pressure reaches the limit setting value, or a fire alarm occurs, or a stop command is received, the APU will automatically stop. If the above situation does not occur during the entire starting process, the APU speed has not reached 55% and the start-up takes 44 seconds, all controls of the power regulator will be disconnected, the starting process ends, and the APU does not reach the independent working speed and automatically stops. After successfully completing the three-stage start of the APU, the speed has reached 55% and has not reached the limit speed, all controls of the power regulator are disconnected, the starting process ends, the starter generator changes from the starting state to the power generation state, and the APU starts successfully. When the APU starts successfully, the output voltage of the starter generator can be controlled by adjusting the starter generator excitation current output by the voltage regulator.

Claims

1. A method for starting and controlling an aircraft auxiliary power unit, characterized in that: The aircraft auxiliary power unit comprises: an APU working state electronic regulator, an APU automatic starter, an APU starting box, and an engine starting accessory; the APU starting box is connected to a starter generator; the method comprises: When the APU automatic starter receives the aircraft APU start command, it controls the working sequence of the engine starting accessories according to the set program, and cooperates with the APU starting box to use armature series resistance voltage reduction starting, full voltage starting and weak magnetic speed regulation to grade the output power of the starter generator, thereby meeting the needs of starting the engine and achieving the purpose of smoothly starting the engine in a low-power and fast-starting manner.

2. The starting control method of an aircraft auxiliary power unit according to claim 1, characterized in that: The APU start command is issued by the aircraft pilot by operating the start button on the APU start control panel.

3. The starting control method of an aircraft auxiliary power unit according to claim 1, characterized in that: The APU working status electronic regulator is connected to the APU temperature sensor and the speed sensor; The APU working status electronic regulator is used to obtain the APU turbine afterburner gas temperature and the APU rotor speed from the APU temperature sensor and the speed sensor.

4. The starting control method of an aircraft auxiliary power unit according to claim 3, characterized in that: The electronic regulator of the APU working state includes: a sensor simulator, a setter combination, a modulator-demodulator, a discontinuous instruction generator and a check logic circuit; The APU working status electronic regulator is used to output the corresponding voltage signal when the APU rotor speed reaches various given speeds, and output the APU parking voltage signal when the APU turbine rear gas temperature reaches the limit temperature and the APU is in various working states and the rotor speed reaches the limit speed. The APU working status electronic regulator compares the electrical signals sent by the APU temperature sensor and speed sensor with the program signals pre-given by the setter, and the difference signal is modulated, demodulated and amplified, and then converted into the command voltage output corresponding to each given speed of the APU by the discontinuous command generator.

5. The starting control method of an aircraft auxiliary power unit according to claim 1, characterized in that: The APU working status electronic regulator has a working self-check function, which is used to check the working condition of the internal circuit to ensure that the APU working status electronic regulator works normally before the APU is started, and the APU is started after the self-check is completed.

6. The starting control method of an aircraft auxiliary power unit according to claim 1, characterized in that: The APU automatic starter includes: timer, relay, transistor, diode, resistor and capacitor; The timer is used to output timing control signals; The APU automatic starter is used to convert the voltage signal output by the electronic regulator according to the APU working status through internal diodes and relays, and control the timing by a timer. It then performs logic conversion through internal diodes and relays to output various control signals with different timings, control the operation of various starting accessories of the auxiliary power unit, and deliver voltage to the APU starting box according to the specified time program.

7. The starting control method of an aircraft auxiliary power unit according to claim 1, characterized in that: The APU starting box includes: a power regulator, a starting voltage reducing resistor R1, a contactor K1, a contactor K2, a relay K3, a relay K4, and a relay K5; the power regulator includes: a stabilizing coil Ww, a control coil Wk, and a working coil Wg; The APU starter box is used to control the operation of the internal relays and contactors after receiving the voltage signal output by the APU automatic starter, so that the internal power regulator controls the starter generator to start in stages; The starting voltage-dropping resistor R1, the contactor K1, the working coil Wg and the armature circuit of the starter generator are connected in series, and the starting voltage-dropping resistor R1 is connected to a DC power supply; the contactor K2 is arranged in parallel at both ends of the starting voltage-dropping resistor and the contactor K1; The adjustable resistor R4, the control coil Wk, the stabilizing coil Ww and the relay K5 are connected in series, and the adjustable resistor R4 is connected to the DC power supply through the contacts 5 and 6 of the relay K5; One side of the contacts 1 and 2 of relay K4 is connected to the stabilizing coil Ww through the contacts 1 and 2 of relay K5, and the other side is connected to the exciting coil Wj of the starter generator; One side of contacts 3 and 4 of relay K4 is connected to the regulator, and the other side is connected to the excitation coil Wj of the starter generator.

8. The starting control method of an aircraft auxiliary power unit according to claim 7, characterized in that: The APU starter box is specifically used to perform the following steps: S1, starting, i.e. at 0s: K1 contactor and K5 relay work, K5 connects the stabilizing coil Ww and control coil Wk of the power regulator; K4 disconnects the power supply circuit from the external voltage regulator to the exciting coil of the starter generator, and connects the power supply circuit from the internal power regulator to the exciting coil of the starter generator, so that the starter generator is excited; at the same time, the APU automatic starter receives power to make the K1 contactor work; connect the armature circuit and working coil Wg of the starter generator, so that the starter generator starts with a series voltage drop resistor, driving the APU rotor to rotate, which is the first stage of starting; S2, 2 seconds after starting: APU automatic starter receives power to operate K2 contactor, short-circuit the starting voltage drop resistor, increase the armature current of the starter generator, increase the torque, and increase the APU speed. This is the second stage of starting; S3, 8 seconds after starting: APU automatic starter receives a call to activate K3 relay, controlling the input of power regulator. The core of power regulator is a controlled high-power variable resistor, which is connected in series to the power supply circuit of the starter generator excitation coil to achieve weak magnetic speed regulation. At this time, the speed of the starter motor is further increased, and the torque is also increased, thereby driving the APU speed to continue to increase. This is the third stage of starting; S4. When the APU speed reaches 55%, the APU automatic starter receives the signal from the APU working status electronic regulator, disconnects the power supply circuit of the APU starting box, the APU starting box stops working, the exciting coil of the starter generator is switched to the external voltage regulator for power supply, and the starter generator ends the motor working state and switches to the generator state.

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