Discharge self-checking method for a power generation control system

Abstract

The present application relates to a kind of discharge self-checking method of power generation control system, belong to the technical field of self-checking of power generation control system, to solve the problem that existing discharge self-checking method cannot complete several self-checking functions.The method comprises: after system power-on, the power-on self-checking of system is carried out: if high-voltage bus contactor closure is monitored, and the absolute value of motor speed is less than motor start speed threshold, enter zero drift self-checking state;After zero drift self-checking state passes, enter impedance self-checking state, open three-phase high-frequency IGBT control signal, to carry out impedance self-checking;After impedance self-checking state passes, close three-phase high-frequency IGBT control signal;After system power-off, the power-off self-checking of system is carried out: enter impedance self-checking state;After impedance self-checking state passes, the system is powered off actively discharged for predetermined duration based on the three-phase high-frequency IGBT control signal, enter power-off active discharge self-checking state;After power-off active discharge self-checking state passes, close three-phase high-frequency IGBT control signal.

Description

Technical Field

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

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

[0003] For the self-test function of the generator controller, it is necessary not only to realize power-on self-test and locate the fault to a certain functional module (such as analog sampling module, IGBT module, etc.), but also to realize the functions of power-on sampling zero drift online update, power-off self-test, power-off active discharge and power-off active discharge self-test.

[0004] Analysis revealed that existing technologies lack a discharge self-testing method for power generation control systems that can integrate the above functions. Therefore, it is necessary to study the implementation process of related technologies in order to better complete the discharge self-testing process. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a discharge self-test method for a power generation control system to solve the problem that existing discharge self-test methods cannot complete several discharge self-test functions.

[0006] This invention discloses a discharge self-test method for a power generation control system, comprising:

[0007] After the system is powered on, a power-on self-test is performed, including:

[0008] 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.

[0009] 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.

[0010] After the impedance self-test passes, the three-phase high-frequency IGBT control signal is turned off.

[0011] After the system is powered off, a power-off self-test is performed on the system, including:

[0012] Enter impedance self-test mode;

[0013] 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.

[0014] After the power-down active discharge self-test passes, the three-phase high-frequency IGBT control signal is turned off.

[0015] Based on the above solution, the present invention also makes the following improvements:

[0016] Based on a further improvement to the above method, in the zero-drift self-test state, the following is performed:

[0017] 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;

[0018] 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.

[0019] 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.

[0020] Based on a further improvement to the above method, in the impedance self-test state, the following is performed:

[0021] 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.

[0022] 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.

[0023] If the self-test impedance value of each phase matches the actual impedance value of that phase, the impedance self-test is passed; otherwise, the impedance self-test is failed. The location of the circuit fault is determined 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.

[0024] Based on a further improvement to the above method, the determination of 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 specifically involves:

[0025] 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.

[0026] 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.

[0027] Based on further improvements to the above method, the actual impedance values ​​of each phase are obtained in the following way:

[0028] Under the condition that the system is fault-free, enter the impedance self-test state multiple times and acquire impedance self-test sampling data;

[0029] 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;

[0030] The average value of the three-phase self-test impedance values ​​sampled multiple times is taken as the actual impedance value of each phase;

[0031] The average value of the self-tested bus voltage samples from multiple samplings is taken as the actual bus voltage.

[0032] Based on further improvements to the above method, the self-test impedance values ​​of each phase are calculated using the following formula:

[0033] Z gm =U m / I gm (1)

[0034] 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.

[0035]

[0036]

[0037] 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.

[0038] Based on a further improvement to the above method, in the power-down active discharge self-test state, the following is performed:

[0039] 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.

[0040] Based on a further improvement of the above method, 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.

[0041] Based on a further improvement of the above method, the motor starting speed threshold is 5 rpm.

[0042] Based on a further improvement of the above method, the predetermined duration is 3 seconds.

[0043] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0044] The discharge self-test method for a power generation control system provided by this invention has the following beneficial effects:

[0045] The discharge self-test process differs depending on whether it's power-on or power-off. 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 self-test are performed. During power-off self-test, the three-phase motor current sampling and IGBT module self-test are performed, followed by active discharge and active discharge fault detection. This achieves a discharge self-test method for the power generation control system that integrates self-testing, online zero drift updating, and active discharge. It effectively improves the discharge self-test efficiency of the power generation control system, reduces the difficulty of discharge self-testing, and has high promotional value.

[0046] 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

[0047] 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.

[0048] Figure 1 This is a block diagram of the power generation control system.

[0049] Figure 2 This is a schematic diagram of the discharge self-test method for a power generation control system provided in an embodiment of the present invention. Detailed Implementation

[0050] 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.

[0051] A specific embodiment of the present invention discloses a discharge self-test method for a power generation control system, the flowchart of which is shown below. Figure 2 As shown, it includes:

[0052] After the system is powered on, a power-on self-test is performed, including:

[0053] (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 zero drift self-test state is entered.

[0054] 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 motor can enter the zero drift state.

[0055] In the zero-drift self-test state, perform the following:

[0056] 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;

[0057] 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.

[0058] 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.

[0059] 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,

[0060] 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.

[0061] 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.

[0062] 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.

[0063] (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.

[0064] 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.

[0065] Specifically, in the impedance self-test state, the following is performed:

[0066] 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.

[0067] 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;

[0068] Steps 2-3: If the self-test impedance value of each phase matches the actual impedance value of that phase, the impedance self-test is passed; otherwise, the impedance self-test fails. In this case, the circuit fault location is determined 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. The specific process is described as follows:

[0069] 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.

[0070] 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.

[0071] 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.

[0072] 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:

[0073] Under the condition that the system is fault-free, enter the impedance self-test state multiple times and acquire impedance self-test sampling data;

[0074] 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;

[0075] The average value of the three-phase self-test impedance values ​​sampled multiple times is taken as the actual impedance value of each phase;

[0076] The average value of the self-tested bus voltage samples from multiple samplings is taken as the actual bus voltage.

[0077] In the specific implementation process, the self-test impedance value of each phase can be calculated according to the following formula:

[0078] Z gm =U m / I gm (1)

[0079] 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.

[0080]

[0081]

[0082] 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.

[0083] (3) After the impedance self-test is passed, turn off the three-phase high-frequency IGBT control signal; then, set the discharge completion flag to position 1.

[0084] After the system is powered off, a power-off self-test is performed on the system, including:

[0085] (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.

[0086] (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.

[0087] 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 maintained 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 completely dissipated, thereby ensuring the safety and reliability of the power generation system.

[0088] Once the power-down active discharge is complete, the system will enter the power-down active discharge self-test state.

[0089] (3) Enter the power-down active discharge self-test state;

[0090] In the power-down active discharge self-test state, the following is executed:

[0091] 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.

[0092] (4) After the power-down active discharge self-test is passed, turn off the three-phase high-frequency IGBT control signal. Then, set the discharge completion flag to 1.

[0093] In this embodiment, the definition table of discharge self-test fault codes is shown in Table 1.

[0094] Table 1 Definition of Discharge Self-Test Fault Codes

[0095]

[0096]

[0097] In summary, compared with existing technologies, the discharge self-test method for the power generation control system provided in this embodiment executes different procedures depending on whether the power is on or off. During power-on self-test, fault detection is performed on the sampled zero drift, and the zero drift value is updated online. Then, self-testing is performed on the three-phase motor current sampling and IGBT module. During power-off self-test, self-testing is performed on the three-phase motor current sampling and IGBT module, followed by active discharge and active discharge fault detection. This achieves a discharge self-test method for the power generation control system that integrates self-testing, online zero drift updating, and active discharge, effectively improving the discharge self-testing efficiency of the power generation control system and reducing the difficulty of discharge self-testing, thus possessing high promotional value.

[0098] 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.

[0099] 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 discharge self-checking method of a power generation control system, characterized by, The system comprises: After the system is powered on, the system is subjected to a power-on self-test, comprising: If it is monitored that the high-voltage bus contactor is closed and the absolute value of the motor rotating speed is less than the motor starting rotating speed threshold, a zero-drift self-test state is entered; After the zero-drift self-test state is passed, an impedance self-test state is entered, and a three-phase high-frequency IGBT control signal is turned on to perform impedance self-test; After the impedance self-test state is passed, the three-phase high-frequency IGBT control signal is turned off; After the system is powered off, the system is subjected to a power-off self-test, comprising: An impedance self-test state is entered; After the impedance self-test state is passed, the system is subjected to a predetermined time length of power-off active discharge based on the three-phase high-frequency IGBT control signal, and then a power-off active discharge self-test state is entered; After the power-off active discharge self-test state is passed, the three-phase high-frequency IGBT control signal is turned off.

2. The discharge self-checking method of the power generation control system according to claim 1, characterized by, In the zero-drift self-test state, the following is performed: Zero-drift sampling data is obtained, comprising: three-phase current self-test sampling values, three-phase voltage self-test sampling values and bus current self-test sampling values; The zero-drift sampling data is subjected to zero-drift self-test, if each zero-drift sampling data meets the corresponding zero-drift value allowable range, the zero-drift self-test state is passed, and the zero-drift value is updated as the zero-drift sampling data; Otherwise, the zero-drift self-test state is not passed, fault positioning is performed according to the zero-drift sampling data which fails the zero-drift self-test, the corresponding fault position 1 of the fault code is determined, and then a fault state is entered.

3. The discharge self-checking method of the power generation control system according to claim 1, characterized by, In the impedance self-test state, the following is performed: Impedance self-test sampling data is obtained, comprising: periodically obtaining three-phase current self-test sampling values, three-phase voltage self-test sampling values under system stable condition, and obtaining bus voltage self-test sampling values after t1 time when the three-phase high-frequency IGBT control signal is turned on; Based on the three-phase current self-test sampling values and the three-phase voltage self-test sampling values under system stable condition, three-phase self-test impedance values are obtained; If each phase self-test impedance value is consistent with the actual impedance value of the phase, the impedance self-test state is passed; otherwise, the impedance self-test state is not passed; the circuit fault position is determined according to each phase self-test impedance value and each phase actual impedance value, as well as bus voltage self-test sampling values and bus actual voltage values.

4. The discharge self-checking method of the power generation control system according to claim 3, characterized by, The circuit fault position determined according to each phase self-test impedance value and each phase actual impedance value, as well as bus voltage self-test sampling values and bus actual voltage values is specifically: If a certain phase self-test impedance value is not consistent with the actual impedance value of the phase, and the bus voltage self-test sampling value is consistent with the bus actual voltage, the current sampling and conditioning circuit of the phase is faulty; If a certain phase self-test impedance value is not consistent with the actual impedance value of the phase, and the bus voltage self-test sampling value is not consistent with the bus actual voltage, the IGBT module of the phase on the motor side is faulty.

5. The discharge self-checking method of the power generation control system according to claim 3, characterized by, Each phase actual impedance value is obtained in the following manner: Under the condition that the system has no fault, the impedance self-test state is entered multiple times and impedance self-test sampling data is obtained; Based on the three-phase current self-test sampling values and the three-phase voltage self-test sampling values under system stable condition obtained each time, three-phase self-test impedance values are obtained; The average of the three-phase self-test impedance values obtained by multiple sampling is taken as each phase actual impedance value; The average of the bus voltage self-test sampling values obtained by multiple sampling is taken as the bus actual voltage.

6. The discharge self-checking method of the power generation control system according to any one of claims 3 to 5, characterized by, Each phase self-test impedance value is calculated according to the following formula: Z gm = U m / I gm (1) wherein Z gm represents the mth phase self-checking impedance value, U m is the mth phase voltage effective value, I gm is the mth phase current effective value, m ∈ {a, b, c} and corresponds to a three-phase circuit; wherein, u m (t) is the mth phase voltage self-checking sampling value at the tth moment in a cycle under the condition of system stability, i gm (t) is the mth phase current self-checking sampling value at the tth moment in a cycle under the condition of system stability, and T is the cycle of the three-phase high-frequency IGBT control signal.

7. The discharge self-checking method of the power generation control system according to claim 1, characterized by, In the powered-off active discharge self-checking state, the following are performed: In the powered-off active discharge self-checking state, the bus voltage self-checking sampling value is monitored, if less than 60V, the powered-off active discharge self-checking state passes; otherwise, the powered-off active discharge self-checking state does not pass, and the fault positioning is motor side IGBT module fault, and the corresponding fault position 1 of the fault code is set.

8. The discharge self-checking method of the power generation control system according to claim 1, characterized by, The three-phase high-frequency IGBT control signal is a three-phase sinusoidal alternating current signal with a frequency of 600Hz and an amplitude of 0.

8.

9. The discharge self-checking method of the power generation control system according to claim 1, characterized by, The motor starting rotation speed threshold is 5rpm.

10. The discharge self-checking method of the power generation control system according to claim 1, characterized by, The predetermined time length is 3s.

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