A method for switching control of a self-checking state of a power generation control system

Abstract

The application relates to a switching control method for the self-checking state of a power generation control system, and belongs to the technical field of power supply systems. The method solves the problem that there is no comprehensive state switching method in the prior art. The method comprises the following steps: monitoring weak current on the system, and entering a low-voltage standby state; monitoring a high-voltage bus contactor closing signal and keeping the signal for a first time length, switching from the low-voltage standby state to a power-on self-checking state, and performing power-on self-checking, generating a power-on self-checking completion signal after passing the self-checking, and switching to a fault state if the self-checking fails; monitoring the power-on self-checking completion signal and keeping the signal for a second time length, and continuously monitoring the high-voltage bus contactor closing signal, switching from the power-on self-checking state to a high-voltage standby state; monitoring the motor rotating speed in a preset low rotating speed range and keeping the rotating speed for a third time length, and continuously monitoring the high-voltage bus contactor opening signal, switching from the high-voltage standby state to a power-off self-checking state, and performing power-off self-checking, generating a power-off self-checking completion signal after passing the self-checking, and switching to the fault state if the self-checking fails.

Description

Technical Field

[0001] This invention relates to the field of power supply system technology, and in particular to a switching control method for the self-test state of a power generation control system. Background Technology

[0002] The power generation control equipment mainly consists of a permanent magnet synchronous generator, cables, and a power generation control system, such as... Figure 1 This is a block diagram of the power generation control equipment. After the permanent magnet synchronous generator starts, mechanical energy is transferred to the generator rotor through the transmission mechanism. Then, by controlling the switching on and off of the insulated gate bipolar transistor (IGBT) in the power generation control system, the DC bus voltage is stabilized at 600V.

[0003] The state switching of the power generation control system involves multiple states such as low voltage, high voltage, power-on self-test, power-off self-test, and fault state. How to achieve automatic switching between multiple states of the power generation control system is an urgent problem to be solved. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a switching control method for the self-test state of a power generation control system, in order to solve the problem of the lack of a comprehensive and automated state switching method for power generation control systems in the prior art.

[0005] This invention discloses a switching control method for the self-test state of a power generation control system, comprising:

[0006] If a weak current is detected on the system, it enters a low-voltage standby state.

[0007] If a high-voltage bus contactor closure signal is detected and maintained for a first duration, the system switches from low-voltage standby mode to power-on self-test mode. In power-on self-test mode, a power-on self-test is performed. If the power-on self-test passes, a power-on self-test completion signal is generated. If the power-on self-test fails, the system switches from power-on self-test mode to fault mode.

[0008] If a power-on self-test completion signal is detected and maintained for a second duration, and a high-voltage bus contactor closing signal is continuously detected during this process, the power-on self-test state will be switched to the high-voltage standby state.

[0009] If the motor speed is monitored to remain within the preset low speed range for a third time, and the high-voltage bus contactor disconnection signal is continuously monitored during this process, the system switches from high-voltage standby state to power-down self-test state. In the power-down self-test state, a power-down self-test is performed. If the power-down self-test passes, a power-down self-test completion signal is generated. If the power-down self-test fails, the system switches from power-down self-test state to fault state.

[0010] Based on the above solution, the present invention makes the following improvements:

[0011] Furthermore, it also includes:

[0012] After detecting the power-down self-test completion signal, if the high-voltage bus voltage is monitored to remain within the preset low voltage range for four hours, and the high-voltage bus contactor closing signal is continuously monitored during this process, the power-down self-test state will be switched to the low-voltage standby state.

[0013] Furthermore, when the host computer controls the high-voltage bus contactor to disconnect, it generates a high-voltage bus contactor disconnection signal and continuously outputs it;

[0014] When the host computer controls the high-voltage bus contactor to close, it generates a high-voltage bus contactor closing signal and outputs it continuously.

[0015] The high-voltage bus contactor is connected in series on the high-voltage bus.

[0016] Furthermore, a power-on self-test is performed in the power-on self-test state, including:

[0017] If a high-voltage bus contactor closing signal is detected and the absolute value of the motor speed is less than the motor starting speed threshold, the system enters the zero-drift self-test state.

[0018] After passing the zero-drift self-test, it enters the impedance self-test state and activates the three-phase high-frequency IGBT control signal to perform impedance self-test.

[0019] After the impedance self-test is passed, the three-phase high-frequency IGBT control signal is turned off, and a power-on self-test completion signal is generated.

[0020] Furthermore, a power-down self-test is performed in the power-down self-test state, including:

[0021] Enter impedance self-test mode;

[0022] After the impedance self-test is passed, the system performs a predetermined power-down active discharge based on the three-phase high-frequency IGBT control signal, and then enters the power-down active discharge self-test state.

[0023] After the power-down active discharge self-test is passed, the three-phase high-frequency IGBT control signals are turned off, and a power-down self-test completion signal is generated.

[0024] Furthermore, in the zero-drift self-test state, the following is performed:

[0025] Acquire zero-drift sampling data, including: three-phase current self-test sampling values, three-phase voltage self-test sampling values, and bus current self-test sampling values;

[0026] Perform a zero-drift self-check on the zero-drift sampled data. If each zero-drift sampled data meets the corresponding zero-drift value allowable range, the zero-drift self-check status is passed, and the zero-drift value is updated to the zero-drift sampled data.

[0027] Otherwise, if the zero-drift self-test fails, the fault location is determined based on the zero-drift sampling data of the failed zero-drift self-test, the corresponding fault code is set to 1, and then the fault state is entered.

[0028] Furthermore, in the impedance self-test state, the following is performed:

[0029] Acquire impedance self-test sampling data, including: periodically acquiring the three-phase current self-test sampling value and the three-phase voltage self-test sampling value under stable system conditions, and acquiring the bus voltage self-test sampling value after the three-phase high-frequency IGBT control signal is turned on for time t1.

[0030] Based on the three-phase current self-test sampling values ​​and three-phase voltage self-test sampling values ​​under stable system conditions, the three-phase self-test impedance values ​​are obtained.

[0031] If the self-test impedance value of each phase matches the actual impedance value of that phase, then the impedance self-test is passed; otherwise,

[0032] If the impedance self-test fails, determine the circuit fault location based on the self-test impedance value of each phase, the actual impedance value of each phase, the bus voltage self-test sampling value, and the actual bus voltage value. Set the corresponding fault code to 1, and then enter the fault state.

[0033] Furthermore, the step of determining the circuit fault location based on the self-test impedance value of each phase, the actual impedance value of each phase, the self-test sampling value of the bus voltage, and the actual bus voltage value includes:

[0034] If the self-test impedance value of a certain phase does not match the actual impedance value of that phase, but the self-test sampling value of the bus voltage matches the actual bus voltage, then the current sampling and conditioning circuit of that phase is faulty.

[0035] If the self-test impedance value of a certain phase does not match the actual impedance value of that phase, and the self-test sampling value of the bus voltage does not match the actual bus voltage, then the IGBT module on the motor side of that phase is faulty.

[0036] Furthermore, the actual impedance values ​​of each phase are obtained through the following methods:

[0037] Under the condition that the system is fault-free, enter the impedance self-test state multiple times and acquire impedance self-test sampling data;

[0038] Based on the three-phase current self-test sampling values ​​and three-phase voltage self-test sampling values ​​obtained under the stable system conditions in each sampling, the three-phase self-test impedance value is obtained;

[0039] The average value of the three-phase self-test impedance values ​​sampled multiple times is taken as the actual impedance value of each phase;

[0040] The average value of the self-tested bus voltage samples from multiple samplings is taken as the actual bus voltage.

[0041] Furthermore, the values ​​for the first duration, the second duration, the third duration, and the fourth duration are 0.11s, 0.1s, 0.18s, and 0.03s, respectively.

[0042] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0043] The power generation control system self-test state switching control method provided by the present invention involves seamless switching between multiple states such as low voltage, high voltage, power-on self-test, power-off self-test, and fault state, which effectively solves the problem of the lack of a comprehensive and automated power generation control system state switching method in the prior art.

[0044] Furthermore, this invention provides specific execution procedures for power-on self-test and power-off self-test. During power-on self-test, fault detection is performed on the sampled zero drift, and the zero drift value is updated online. Then, self-tests are performed on the three-phase motor current sampling and IGBT module. During power-off self-test, self-tests are performed on the three-phase motor current sampling and IGBT module, followed by active discharge and active discharge fault detection. This achieves a switching control method for the self-test state of a power generation control system that integrates self-testing, online zero drift updating, and active discharge, effectively improving the state switching efficiency and discharge self-testing efficiency of the power generation control system, and reducing the difficulty of state switching and discharge self-testing in the power generation control system. It has high promotional value.

[0045] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0046] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0047] Figure 1 This is a block diagram of the power generation control system.

[0048] Figure 2 This is a state switching transition diagram of a power generation control system provided in an embodiment of the present invention;

[0049] Figure 3 A schematic diagram of the power-on self-test method for a power generation control system provided in an embodiment of the present invention;

[0050] Figure 4 This is a schematic diagram of the power-down self-test method for a power generation control system provided in an embodiment of the present invention. Detailed Implementation

[0051] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0052] A specific embodiment of the present invention discloses a switching control method for the self-test state of a power generation control system, and the state switching transition diagram of the power generation control system is shown below. Figure 2 As shown, it includes:

[0053] Condition C0: If a weak current is detected on the system, it enters a low-voltage standby state S0;

[0054] In low-voltage standby state S0, it waits for the high-voltage bus contactor connected in series with the high-voltage bus to close. The closing / opening of the high-voltage bus contactor is controlled by the host computer. When the host computer controls the high-voltage bus contactor to open, it generates a high-voltage bus contactor open signal and outputs it continuously; when the host computer controls the high-voltage bus contactor to close, it generates a high-voltage bus contactor close signal and outputs it continuously.

[0055] Condition C1: If a high-voltage bus contactor closing signal is detected and maintained for a first duration, the system switches from low-voltage standby state S0 to power-on self-test state S1. In power-on self-test state S1, the power-on self-test enable signal is set to 1, and the power-on self-test is performed. After the power-on self-test passes, a power-on self-test completion signal is generated. Condition C2: If the power-on self-test fails, the system switches from power-on self-test state to fault state S2.

[0056] For example, in one implementation, the first duration was set to 0.11s.

[0057] Condition C3: If a power-on self-test completion signal is detected and maintained for the second duration, and a high-voltage bus contactor closing signal is continuously detected during this process, the system switches from power-on self-test state S1 to high-voltage standby state S3; when the system is no longer in power-on self-test state S1, the power-on self-test enable signal is set to 0. For example, in a certain implementation process, the second duration is 0.1s.

[0058] In high-voltage standby state S3, the system waits for the host computer to send instructions for the next operation, such as power generation or braking, so that the control system can switch to the corresponding state. Alternatively, it can switch back to high-voltage standby state S3 according to instructions from the host computer. The control of states such as power generation and braking is not within the scope of the self-test described in this embodiment, and its specific process will not be described in detail.

[0059] Condition C4: If the motor speed is monitored to remain within a preset low speed range of ±10 rpm (for example, the preset low speed range is preferably [-10 rpm, 10 rpm]) for a third duration, and the high-voltage bus contactor disconnection signal is continuously monitored during this process, the high-voltage standby state S3 is switched to the power-down self-test state S4; in the power-down self-test state S4, the power-down self-test enable signal is set to 1, and the power-down self-test is performed. After the power-down self-test passes, a power-down self-test completion signal is generated; Condition C5: If the power-down self-test fails, the power-down self-test state is switched to the fault state S3.

[0060] For example, in one implementation, the third duration was set to 0.18s.

[0061] In addition, the method also includes:

[0062] Condition C6: After detecting the power-down self-test completion signal, if the high-voltage bus voltage is maintained within a preset low voltage range (preferably [-10V, 10V]) for a fourth duration, and the high-voltage bus contactor closing signal is continuously detected during this process, the system switches from power-down self-test state S4 to low-voltage standby state S0. When no longer in the power-down self-test state, the power-down self-test enable signal is set to 0. For example, in a certain implementation, the fourth duration is 0.03s. In low-voltage standby state S0, the system waits again for the high-voltage bus contactor to close.

[0063] The diagram illustrating the power-on self-test in power-on self-test state S1 is as follows: Figure 3 As shown, it includes:

[0064] (1) If the high-voltage bus contactor is detected to be closed and the absolute value of the motor speed is less than the motor starting speed threshold, the system enters the zero-drift self-test state.

[0065] For example, the motor starting speed threshold is 5 rpm. When the high-voltage bus contactor is detected to be closed and the absolute value of the motor speed is less than 5 rpm, it can be considered that the permanent magnet synchronous motor is not rotating; only when the motor is not rotating can sampling be performed for zero drift monitoring. Therefore, when this condition is met, the zero drift self-test state can be entered.

[0066] In the zero-drift self-test state, perform the following:

[0067] Step 1-1: Obtain zero-drift sampling data, including: three-phase current self-test sampling values, three-phase voltage self-test sampling values, and bus current self-test sampling values;

[0068] Step 1-2: Perform a zero-drift self-check on the zero-drift sampling data. If each zero-drift sampling data meets the corresponding zero-drift value allowable range, the zero-drift self-check status is passed, and the zero-drift value is updated to the zero-drift sampling data, thereby realizing the automatic update of the zero-drift value.

[0069] Otherwise, if the zero-drift self-test fails, the fault location is determined based on the zero-drift sampling data of the failed zero-drift self-test, the corresponding fault code is set to 1, and then the fault state is entered.

[0070] The allowable range of zero-drift values ​​for each zero-drift sampling data can be set according to specific circumstances, which will not be described in detail here; when the zero-drift self-test fails, fault location can be performed based on the zero-drift sampling data that failed the self-test. For example,

[0071] If the self-test sampling value of phase A current does not meet the allowable range of zero drift value of phase A current, the fault is located in the phase A motor current sampling and conditioning circuit. At this time, the fault position corresponding to the phase A motor current sampling and conditioning circuit in the fault code is set to 1. The zero drift self-test process of phase B and C current self-test sampling values ​​is similar and will not be described in detail here.

[0072] If the self-test sampling value of phase A voltage does not meet the allowable range of zero drift value of phase A voltage, the fault is located in the phase A motor voltage sampling and conditioning circuit. At this time, the fault position corresponding to the phase A motor voltage sampling and conditioning circuit in the fault code is set to 1. The zero drift self-test process of phase B and C voltage self-test sampling values ​​is similar and will not be described in detail here.

[0073] If the bus voltage self-test sampling value does not meet the allowable range of zero drift value of the bus voltage, the fault is located as the DC bus current sampling and conditioning circuit. At this time, the fault position corresponding to the DC bus current sampling and conditioning circuit in the fault code is set to 1.

[0074] (2) After passing the zero-drift self-test, it enters the impedance self-test state and turns on the three-phase high-frequency IGBT control signal to perform impedance self-test.

[0075] Preferably, the three-phase high-frequency IGBT control signal is a three-phase sinusoidal AC signal with a frequency of 600Hz and an amplitude of 0.8.

[0076] Specifically, in the impedance self-test state, the following is performed:

[0077] Step 2-1: Obtain impedance self-test sampling data, including: periodically acquiring the three-phase current self-test sampling value and the three-phase voltage self-test sampling value under stable system conditions, and acquiring the bus voltage self-test sampling value after the three-phase high-frequency IGBT control signal is turned on for time t1.

[0078] Step 2-2: Based on the three-phase current self-test sampling values ​​and three-phase voltage self-test sampling values ​​under stable system conditions, obtain the three-phase self-test impedance values;

[0079] Steps 2-3: If the self-test impedance value of each phase matches the actual impedance value of that phase, the impedance self-test state is passed; otherwise, the impedance self-test state is not passed. At this time, the circuit fault location is determined according to the self-test impedance value of each phase, the actual impedance value of each phase, the bus voltage self-test sampling value, and the actual bus voltage value. The corresponding fault code is set to 1, and then the fault state is entered.

[0080] The specific process is described as follows:

[0081] If the self-test impedance value of a certain phase does not match the actual impedance value of that phase, but the self-test sampling value of the bus voltage matches the actual bus voltage, then the current sampling and conditioning circuit of that phase is faulty.

[0082] If the self-test impedance value of a certain phase does not match the actual impedance value of that phase, and the self-test sampling value of the bus voltage does not match the actual bus voltage, then the IGBT module on the motor side of that phase is faulty.

[0083] It should be noted that two compared data points are considered to be in agreement if the deviation between them meets the set deviation threshold. The deviation threshold can be set adaptively according to the system's design requirements. If higher accuracy is required for system operation, the deviation threshold can be set relatively smaller; if lower accuracy is required, the deviation threshold can be set relatively larger.

[0084] It should be noted that the actual impedance values ​​of each phase and the actual bus voltage mentioned in steps 2-3 can be obtained in advance through the following methods:

[0085] Under the condition that the system is fault-free, enter the impedance self-test state multiple times and acquire impedance self-test sampling data;

[0086] Based on the three-phase current self-test sampling values ​​and three-phase voltage self-test sampling values ​​obtained under the stable system conditions in each sampling, the three-phase self-test impedance value is obtained;

[0087] The average value of the three-phase self-test impedance values ​​sampled multiple times is taken as the actual impedance value of each phase;

[0088] The average value of the self-tested bus voltage samples from multiple samplings is taken as the actual bus voltage.

[0089] In the specific implementation process, the self-test impedance value of each phase can be calculated according to the following formula:

[0090] Z gm =U m / I gm (1)

[0091] Among them, Z gm U represents the self-test impedance value of the m-th phase. m I is the effective value of the voltage of the m-th phase.gm Let be the effective value of the current in the m-th phase, where m∈{a,b,c} corresponds to the three-phase circuit.

[0092]

[0093]

[0094] Among them, u m (t) represents the self-test sampled value of the m-th phase voltage at time t within one cycle under stable system conditions, where i gm (t) represents the self-test sampling value of the m-th phase current at time t within one cycle under stable system conditions, and T is the period of the three-phase high-frequency IGBT control signal.

[0095] (3) After the impedance self-test is passed, the three-phase high-frequency IGBT control signal is turned off, and a power-on self-test completion signal is generated.

[0096] A schematic diagram of the power-down self-test in state S4 is shown below. Figure 4 As shown, it includes:

[0097] (1) Enter the impedance self-test state; the process is the same as the impedance self-test state when powered on, and will not be described again here.

[0098] (2) After the impedance self-test is passed, the system is powered down and actively discharged for a predetermined time based on the three-phase high-frequency IGBT control signal.

[0099] The three-phase high-frequency IGBT control signal for the motor is still a 600Hz three-phase sinusoidal AC signal with an amplitude of 0.8, which is held for 3 seconds before power-off active discharge. During this process, by turning on the IGBT module, the residual current on the bus capacitor can be dissipated, thereby ensuring the safety and reliability of the power generation control system.

[0100] Once the power-down active discharge is complete, the system will enter the power-down active discharge self-test state.

[0101] (3) Enter the power-down active discharge self-test state;

[0102] In the power-down active discharge self-test state, the following is executed:

[0103] Monitor the bus voltage self-test sampling value under the power-down active discharge self-test state. If it is less than 60V, the power-down active discharge self-test state passes; otherwise, the power-down active discharge self-test state fails, the fault is located as a fault in the motor side IGBT module, and the corresponding fault code is set to 1.

[0104] (4) After the power-down active discharge self-test is passed, the three-phase high-frequency IGBT control signal is turned off. Then, a power-down self-test completion signal is generated.

[0105] In this embodiment, the definition table of power-on and power-off self-test fault codes is shown in Table 1.

[0106] Table 1. Definition of Power-On Self-Test Fault Codes

[0107]

[0108]

[0109] In summary, compared with existing technologies, the power generation control system self-test state switching control method provided in this embodiment involves seamless switching between multiple states, including low voltage, high voltage, power-on self-test, power-off self-test, and fault state. This effectively solves the problem of the lack of comprehensive and automated state switching methods for power generation control systems in existing technologies. Furthermore, this embodiment also provides the specific execution flow for power-on self-test and power-off self-test. During power-on self-test, fault detection is performed on the sampled zero drift, and the zero drift value is updated online. Then, the three-phase motor current sampling and IGBT module are self-tested. During power-off self-test, the three-phase motor current sampling and IGBT module are self-tested, followed by active discharge and active discharge fault detection. This achieves a power generation control system self-test state switching control method that integrates seamless switching between multiple states, online self-testing, zero drift updating, and active discharge. It effectively improves the state switching efficiency and discharge self-test efficiency of the power generation control system, reduces the difficulty of state switching and discharge self-testing, and has high promotional value.

[0110] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0111] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for switching the self-test state of a power generation control system, characterized in that, include: If a weak current is detected on the system, it enters a low-voltage standby state. If a high-voltage bus contactor closure signal is detected and maintained for a first duration, the system switches from low-voltage standby mode to power-on self-test mode. In power-on self-test mode, a power-on self-test is performed. If the power-on self-test passes, a power-on self-test completion signal is generated. If the power-on self-test fails, the system switches from power-on self-test mode to fault mode. If a power-on self-test completion signal is detected and maintained for a second duration, and a high-voltage bus contactor closing signal is continuously detected during this process, the power-on self-test state will be switched to the high-voltage standby state. If the motor speed is monitored to remain within the preset low speed range for a third time, and the high-voltage bus contactor disconnection signal is continuously monitored during this process, the system switches from high-voltage standby state to power-down self-test state. In the power-down self-test state, a power-down self-test is performed. If the power-down self-test passes, a power-down self-test completion signal is generated. If the power-down self-test fails, the system switches from power-down self-test state to fault state.

2. The switching control method for the self-test state of the power generation control system according to claim 1, characterized in that, Also includes: After detecting the power-down self-test completion signal, if the high-voltage bus voltage is monitored to remain within the preset low voltage range for four hours, and the high-voltage bus contactor closing signal is continuously monitored during this process, the power-down self-test state will be switched to the low-voltage standby state.

3. The switching control method for the self-test state of the power generation control system according to claim 2, characterized in that, When the host computer controls the high-voltage bus contactor to disconnect, it generates a high-voltage bus contactor disconnection signal and outputs it continuously. When the host computer controls the high-voltage bus contactor to close, it generates a high-voltage bus contactor closing signal and outputs it continuously. The high-voltage bus contactor is connected in series on the high-voltage bus.

4. The switching control method for the self-test state of the power generation control system according to any one of claims 1-3, characterized in that, Perform a power-on self-test during the power-on self-test state, including: If a high-voltage bus contactor closing signal is detected and the absolute value of the motor speed is less than the motor starting speed threshold, the system enters the zero-drift self-test state. After passing the zero-drift self-test, it enters the impedance self-test state and activates the three-phase high-frequency IGBT control signal to perform impedance self-test. After the impedance self-test is passed, the three-phase high-frequency IGBT control signal is turned off, and a power-on self-test completion signal is generated.

5. The switching control method for the self-test state of the power generation control system according to claim 4, characterized in that, Perform a power-down self-test during the power-down self-test state, including: Enter impedance self-test mode; After the impedance self-test is passed, the system performs a predetermined power-down active discharge based on the three-phase high-frequency IGBT control signal, and then enters the power-down active discharge self-test state. After the power-down active discharge self-test is passed, the three-phase high-frequency IGBT control signals are turned off, and a power-down self-test completion signal is generated.

6. The switching control method for the self-test state of the power generation control system according to claim 4, characterized in that, In the zero-drift self-test state, perform the following: Acquire zero-drift sampling data, including: three-phase current self-test sampling values, three-phase voltage self-test sampling values, and bus current self-test sampling values; Perform a zero-drift self-check on the zero-drift sampled data. If each zero-drift sampled data meets the corresponding zero-drift value allowable range, the zero-drift self-check status is passed, and the zero-drift value is updated to the zero-drift sampled data. Otherwise, if the zero-drift self-test fails, the fault location is determined based on the zero-drift sampling data of the failed zero-drift self-test, the corresponding fault code is set to 1, and then the fault state is entered.

7. The switching control method for the self-test state of the power generation control system according to claim 4, characterized in that, In the impedance self-test state, perform the following: Acquire impedance self-test sampling data, including: periodically acquiring the three-phase current self-test sampling value and the three-phase voltage self-test sampling value under stable system conditions, and acquiring the bus voltage self-test sampling value after the three-phase high-frequency IGBT control signal is turned on for time t1. Based on the three-phase current self-test sampling values ​​and three-phase voltage self-test sampling values ​​under stable system conditions, the three-phase self-test impedance values ​​are obtained. If the self-test impedance value of each phase matches the actual impedance value of that phase, then the impedance self-test is passed; otherwise, If the impedance self-test fails, determine the circuit fault location based on the self-test impedance value of each phase, the actual impedance value of each phase, the bus voltage self-test sampling value, and the actual bus voltage value. Set the corresponding fault code to 1, and then enter the fault state.

8. The switching control method for the self-test state of the power generation control system according to claim 7, characterized in that, The method of determining the circuit fault location based on the self-test impedance value of each phase, the actual impedance value of each phase, the self-test sampling value of the bus voltage, and the actual bus voltage value includes: If the self-test impedance value of a certain phase does not match the actual impedance value of that phase, but the self-test sampling value of the bus voltage matches the actual bus voltage, then the current sampling and conditioning circuit of that phase is faulty. If the self-test impedance value of a certain phase does not match the actual impedance value of that phase, and the self-test sampling value of the bus voltage does not match the actual bus voltage, then the IGBT module on the motor side of that phase is faulty.

9. The switching control method for the self-test state of the power generation control system according to claim 7, characterized in that, The actual impedance values ​​of each phase are obtained using the following method: Under the condition that the system is fault-free, enter the impedance self-test state multiple times and acquire impedance self-test sampling data; Based on the three-phase current self-test sampling values ​​and three-phase voltage self-test sampling values ​​obtained under the stable system conditions in each sampling, the three-phase self-test impedance value is obtained; The average value of the three-phase self-test impedance values ​​sampled multiple times is taken as the actual impedance value of each phase; The average value of the self-tested bus voltage samples from multiple samplings is taken as the actual bus voltage.

10. The switching control method for the self-test state of the power generation control system according to claim 2, characterized in that, The values ​​for the first, second, third, and fourth durations are 0.11s, 0.1s, 0.18s, and 0.03s, respectively.

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