A continuous commutation failure suppression method based on arc chute dynamic compensation

Abstract

The application discloses a continuous commutation failure suppression method based on arc extinction angle dynamic compensation, comprising the following steps: obtaining an arc extinction angle theoretical value without commutation failure in a fault recovery process; calculating an arc extinction angle compensation amount according to the arc extinction angle theoretical value; combining the arc extinction angle dynamic compensation enable signal, superimposing the arc extinction angle compensation amount to the fixed arc extinction angle control instruction value, obtaining a fixed arc extinction angle control correction value, so as to suppress the continuous commutation failure in the fault recovery process. By considering the constraints of electrical parameters such as DC current, commutation voltage amplitude, commutation voltage offset angle and the like on the arc extinction angle in the fault recovery process, the arc extinction angle is calculated, and the calculation result is compared with the rated arc extinction angle, so that the arc extinction angle dynamic compensation amount can be obtained. The arc extinction angle compensation amount is more accurate and does not depend on simulation setting, and the system can maintain a higher power transmission level on the basis of suppressing the continuous commutation failure in the fault recovery process.

Description

Technical Field

[0001] This invention relates to the field of high voltage direct current transmission control technology, and in particular to a method for suppressing continuous commutation failure based on dynamic compensation of arc extinction angle. Background Technology

[0002] High-voltage direct current (HVDC) transmission technology based on grid-commutated converters uses thyristors without self-turn-off capability as converter devices. Therefore, commutation failure is prone to occur after a fault in the receiving-end AC system. Commutation failure will cause a drop in DC voltage, a significant increase in DC current, reduce the lifespan of the thyristors, and pose a risk of thyristor damage. Simultaneously, commutation failure will also cause a significant reduction in system transmission power. Generally, the DC system can recover on its own after a single commutation failure. However, if multiple consecutive commutation failures occur during the recovery process, it will cause a significant impact on the AC system, and in severe cases, may even lead to DC system shutdown and power interruption. Therefore, the consequences of consecutive commutation failures during fault recovery are more serious than those of a single commutation failure.

[0003] A fault in the receiving-end AC system leads to commutation failure. During the fault recovery process, the system characteristics are mainly affected by the pole control layer. A typical control block diagram of the inverter-side pole control layer is shown below. Figure 1 As shown. During the fault recovery process, constant current control, current deviation control, and constant extinction angle control work alternately to ensure stable system recovery. Current deviation control is implemented by generating an extinction angle increment Δγ based on the deviation ΔIdc between the current command value and the actual current value. The relationship between the two is... ΔIH is the current deviation saturation value. The current deviation control phase is the period with the highest risk of continuous commutation failure in the system. If the slope of the current deviation control function is not properly selected, it is easy to cause insufficient arc extinction angle compensation during the fault recovery process, resulting in commutation failure.

[0004] To address the aforementioned issues, most existing technologies dynamically adjust the slope of the current deviation control function and the arc extinction angle compensation amount based on the severity of the AC fault. This has achieved some effect in suppressing continuous commutation failures during fault recovery. However, the tuning of the proportional relationship between the slope of the current deviation control function and the arc extinction angle compensation amount and the severity of the AC fault largely depends on extensive simulations. Furthermore, there is a problem of overcompensation leading to limited system power transmission.

[0005] Generally, the more severe the AC fault (the deeper the voltage drop), the more prone the converter is to commutation failure. To minimize commutation failure, the arc-extinguishing angle needs to be increased. Existing technologies mostly dynamically adjust the slope of the current deviation control function and the arc-extinguishing angle compensation based on the severity of the AC fault, achieving some success. When the AC fault is severe, a larger slope of the control function results in a larger arc-extinguishing angle compensation under the same conditions, leading to a larger actual arc-extinguishing angle for the converter. Figure 2 As shown, the specific implementation is as follows: During normal system operation, the current deviation controller's control characteristic is curve 1; when the converter bus voltage drops due to a short-circuit fault in the AC system, the curve slope is increased, resulting in curve 2; after the fault is cleared, the AC bus voltage recovers, and the curve slope is decreased, resulting in curve 3. The tuning of the proportional relationship between the "current deviation control function slope and arc extinction angle compensation" and the "severity of the AC fault" relies heavily on extensive simulations and is difficult to select. Improper selection can lead to problems such as "inability to suppress commutation failure" or "overcompensation resulting in limited system power transmission." Summary of the Invention

[0006] The purpose of this invention is to provide a method for suppressing continuous commutation failure based on dynamic compensation of the arc extinction angle. By considering the constraints of electrical parameters such as DC current, commutation voltage amplitude, and commutation voltage offset angle on the arc extinction angle during the fault recovery process, the arc extinction angle is theoretically calculated. By comparing the above calculation results with the rated arc extinction angle, the dynamic compensation amount of the arc extinction angle can be obtained. This arc extinction angle compensation amount is more accurate and does not depend on simulation tuning. It can maintain a high power transmission level of the system while suppressing continuous commutation failure during the fault recovery process.

[0007] To address the aforementioned technical problems, a first aspect of this invention provides a method for suppressing continuous commutation failure based on dynamic compensation of the arc extinction angle, comprising the following steps:

[0008] Obtain the theoretical value of the arc extinction angle during fault recovery without commutation failure;

[0009] Based on the theoretical value of the arc extinction angle, calculate the arc extinction angle compensation amount;

[0010] By combining the arc extinction angle dynamic compensation enable signal, the arc extinction angle compensation amount is superimposed on the fixed arc extinction angle control command value to obtain the fixed arc extinction angle control correction value, so as to suppress continuous commutation failures during the fault recovery process.

[0011] Furthermore, the theoretical value of the extinguishing angle is:

[0012]

[0013] Where, β N To trigger the lead angle rating, X is the equivalent commutation reactance, k is the primary-to-secondary turns ratio of the converter transformer, and I... dc This is the DC current filter value.

[0014] Further, the calculation of the arc-extinguishing angle compensation amount based on the theoretical value of the arc-extinguishing angle includes:

[0015] Obtain the commutation voltage offset angle after an asymmetrical fault occurs;

[0016] Obtain the dynamic compensation enable signal for the arc extinction angle;

[0017] Obtain the control command value for the extinguishing arc angle;

[0018] Calculate the arc extinction angle compensation amount.

[0019] Furthermore, obtaining the commutation voltage offset angle after the occurrence of an asymmetric fault includes:

[0020] Acquire the three-phase imbalance detection signal;

[0021] Obtain the minimum value of AC bus line voltage amplitude and the rated value of AC bus line voltage amplitude;

[0022] The commutation voltage offset angle is calculated based on the three-phase imbalance detection signal.

[0023] Furthermore, the commutation voltage offset angle is:

[0024]

[0025] Wherein, function f max is the maximum value holding function, and tri1 is the three-phase imbalance detection signal.

[0026] Further, acquiring the three-phase imbalance detection signal includes:

[0027] Obtain the phase voltage of the three-phase AC bus;

[0028] Determine whether the sum of the phase voltages of the three-phase AC bus is greater than the three-phase imbalance detection setting value;

[0029] If so, the value of the three-phase imbalance detection signal is determined to be 1;

[0030] If not, then the value of the three-phase imbalance detection signal is determined to be 0.

[0031] Furthermore, the arc-extinguishing angle compensation amount is Δγ:

[0032]

[0033] Where, γ cal The theoretical value of the arc-extinguishing angle is given. γ is the commutation voltage offset angle. ref is the control command value for the fixed arc extinction angle; tri2 is the enable signal for dynamic compensation of the arc extinction angle.

[0034] Furthermore, the acquisition of the dynamic compensation enable signal for the arc extinction angle includes:

[0035] Acquire the first logic signal, the second logic signal, and the third logic signal;

[0036] Perform an AND operation on the first logic signal, the second logic signal, and the third logic signal to obtain the arc extinction angle dynamic compensation enable signal;

[0037] Among them, when U N -U≤U set2 When, the value of the first logic signal is 0, when U N -U>U set2 At that time, the value of the first logic signal is 1 and the second preset time is extended, U N U is the rated value of the AC bus line voltage amplitude, and U is the minimum value of the AC bus line voltage amplitude. set2 This is the voltage drop detection setting value;

[0038] Where, when γ min When γ ≤ 0, the value of the second logic signal is 0; when γ min When the value is greater than 0, the value of the second logic signal is 1, and the minimum measured value of the arc extinction angle is γ. min ;

[0039] Where, when β inv_i ≤β inv_γ When β is 0, the value of the third logic signal is 0. inv_i >β inv_γ At that time, the value of the third logic signal is 1, β inv_i β is the output value of the constant current controller in the inverter-side control system. inv_γ This is the output value of the constant extinguishing arc angle controller.

[0040] Further, obtaining the minimum value of the AC bus line voltage amplitude includes:

[0041] Obtain the sampled value of the AC bus line voltage;

[0042] The AC bus line voltage sampling value is extracted by constructing voltage sine and cosine components using a second-order generalized integrator to obtain the AC bus line voltage amplitude.

[0043] Obtain the minimum value of the AC bus line voltage amplitude.

[0044] Accordingly, a second aspect of the present invention provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the processor, the instructions being executed by the processor to cause the at least one processor to perform the above-described continuous commutation failure suppression method based on dynamic compensation of arc extinction angle.

[0045] The above-described technical solutions of the embodiments of the present invention have the following beneficial technical effects:

[0046] By considering the constraints of electrical parameters such as DC current, commutation voltage amplitude, and commutation voltage offset angle on the arc extinction angle during fault recovery, the arc extinction angle is theoretically calculated. By comparing the above calculation results with the rated arc extinction angle, the dynamic compensation amount of the arc extinction angle can be obtained. This arc extinction angle compensation amount is more accurate and does not depend on simulation tuning. It can maintain a high power transmission level of the system while suppressing continuous commutation loss during fault recovery. Attached Figure Description

[0047] Figure 1 This is a typical control block diagram of the existing technology's control layer;

[0048] Figure 2 This is a schematic diagram of the ramp function characteristics of existing adaptive current deviation control technology;

[0049] Figure 3 This is a flowchart of the continuous commutation failure suppression method based on dynamic compensation of arc extinction angle provided in the embodiments of the present invention;

[0050] Figure 4 This is an overall control structure block diagram provided in an embodiment of the present invention;

[0051] Figure 5 This is a schematic diagram of the system parameter processing stage provided in an embodiment of the present invention;

[0052] Figure 6 This is a schematic diagram of the three-phase imbalance detection section provided in an embodiment of the present invention;

[0053] Figure 7 This is a schematic diagram of the enable detection part of the suppression method provided in this embodiment of the invention;

[0054] Figure 8 This is a schematic diagram of the compensation method for the arc extinction angle compensation provided in an embodiment of the present invention. Detailed Implementation

[0055] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments and the accompanying drawings. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of the invention. Furthermore, descriptions of well-known structures and techniques are omitted in the following description to avoid unnecessarily obscuring the concept of the invention.

[0056] Figure 3 This is a flowchart of a continuous commutation failure suppression method based on dynamic compensation of arc extinction angle provided in an embodiment of the present invention.

[0057] Figure 4 This is an overall control structure block diagram provided in an embodiment of the present invention.

[0058] Please refer to Figure 3and Figure 4 The first aspect of this invention provides a method for suppressing continuous commutation failure based on dynamic compensation of the arc extinction angle, comprising the following steps:

[0059] S100, obtain the theoretical value of the arc extinction angle during fault recovery without commutation failure.

[0060] S200, calculate the arc extinction angle compensation amount based on the theoretical value of the arc extinction angle.

[0061] S300, combined with the arc extinction angle dynamic compensation enable signal, superimposes the arc extinction angle compensation amount onto the fixed arc extinction angle control command value to obtain the fixed arc extinction angle control correction value, so as to suppress continuous commutation failures during the fault recovery process.

[0062] The above-mentioned continuous commutation failure suppression method based on dynamic compensation of arc extinction angle includes system parameter processing, logical judgment and numerical calculation. The theoretical value of arc extinction angle that does not cause commutation failure during fault recovery is obtained through theoretical calculation. Based on this, the arc extinction angle compensation amount is calculated and superimposed on the fixed arc extinction angle control command value.

[0063] Figure 5 This is a schematic diagram of the system parameter processing stage provided in an embodiment of the present invention.

[0064] Please refer to Figure 5 The input to the system parameter processing stage is the AC bus line voltage sampling value u. ab u bc u ca and DC current sampling value i dc The output of the system parameter processing stage is the DC current filter value I. dc And the minimum amplitude U of the AC bus line voltage.

[0065] The DC current sample value is filtered using a moving average filter, i dc with I dc Satisfy I dc =f MAF (i dc ), where f MAF The mathematical function of the moving average filter; the AC bus line voltage amplitude is extracted by constructing voltage sine and cosine components using a second-order generalized integrator, U and u ab u bc u ca Satisfying U = min[f SOGI (u ab ), f SOGI (u bc ), f SOGI (u ca )], where f SOGIThis is a mathematical function based on a voltage extraction method using a second-order generalized integrator.

[0066] Figure 6 This is a schematic diagram of the three-phase imbalance detection section provided in an embodiment of the present invention.

[0067] In addition, please refer to Figure 6 The logic judgment process includes two parts: three-phase imbalance detection and suppression method enable detection.

[0068] The main function of the three-phase unbalance detection section is to detect the degree of imbalance in the three-phase AC voltage. The module input is the three-phase AC bus phase voltage u. a u b u c The module output is signal tri1, when (u a +u b +u c )≤U set1 When the detection module output signal tri1 is set to 0, when (u a +u b +u c )>U set1 At that time, the detection module output signal tri1 is set to 1 and widened for 200ms, where U set1 This is the setting value for three-phase imbalance detection.

[0069] Figure 7 This is a schematic diagram of the enable detection part of the suppression method provided in this embodiment of the invention.

[0070] Please refer to Figure 7 The suppression method enable detection section mainly assigns a value to the arc extinction angle dynamic compensation enable signal tri2. The module inputs are the minimum amplitude of the AC bus line voltage U and the minimum measured value of the arc extinction angle γ. min The inverter-side control system constant current controller outputs β inv_i and the output β of the constant extinguishing arc angle controller inv_γ Let flag1, flag2, and flag3 be the internal logic signals of the suppression method enabling detection module. When U N -U≤U set2 When, flag1 is set to 0, when U N -U>U set2 At that time, flag1 is set to 1 and the width is expanded for 200ms, where U N U is the rated amplitude of the AC bus line voltage. set2 This is the voltage drop detection setting value; when γ min When γ ≤ 0, flag2 is set to 0; when γ ≤ 0, flag2 is set to 0 min When β > 0, flag2 is set to 1; when β > 0, flag2 is set to 1. inv_i ≤β inv_γWhen β is set to 0, flag3 is set to 0. inv_i >β inv_γ At that time, flag3 is set to 1.

[0071] The suppression method enables the detection module output signal tri2 to be obtained through an AND logic operation using flag1, flag2, and flag3.

[0072] The arc-extinguishing angle compensation amount superimposed on the arc-extinguishing angle control command value is obtained from the numerical calculation stage. The theoretical calculated value of the arc-extinguishing angle is... Where β N To trigger the lead angle rating, X is the equivalent commutation reactance, k is the primary-to-secondary turns ratio of the converter transformer, and I... dc This is the DC current filter value; the commutation voltage offset angle after an asymmetrical fault occurs is... Where the function f max This is a function that preserves the maximum value. When tri1 = 0, the function outputs 0; when tri1 = 1, the function outputs the calculation formula. The maximum value during this period.

[0073] Figure 8 This is a schematic diagram of the compensation method for the arc extinction angle compensation provided in an embodiment of the present invention.

[0074] For details, please refer to Figure 8 The theoretical value of the extinguishing arc angle is:

[0075]

[0076] Where, β N To trigger the lead angle rating, X is the equivalent commutation reactance, k is the primary-to-secondary turns ratio of the converter transformer, and I... dc This is the DC current filter value.

[0077] Further, in step S200, the arc-extinguishing angle compensation amount is calculated based on the theoretical value of the arc-extinguishing angle, including:

[0078] S210, obtain the commutation voltage offset angle after an asymmetrical fault occurs.

[0079] S220, obtain the dynamic compensation enable signal for the arc extinction angle.

[0080] Further, in step S220, obtaining the dynamic compensation enable signal for the arc extinction angle includes:

[0081] S221, acquire the first logic signal, the second logic signal and the third logic signal.

[0082] S221 performs an AND operation on the first logic signal, the second logic signal, and the third logic signal to obtain the arc extinction angle dynamic compensation enable signal.

[0083] Among them, when U N -U≤U set2 When, the value of the first logic signal is 0, when U N -U>U set2 At that time, the value of the first logic signal is 1 and the second preset time is extended, U N U is the rated amplitude of the AC bus line voltage, and U is the minimum amplitude of the AC bus line voltage. set2 This is the voltage drop detection setting value.

[0084] Where, when γ min When γ ≤ 0, the value of the second logic signal is 0; when γ min When the value is greater than 0, the value of the second logic signal is 1, and the minimum measured value of the arc extinction angle is γ. min .

[0085] Where, when β inv_i ≤β inv_γ When β is 0, the value of the third logic signal is 0. inv_i >β inv_γ At that time, the value of the third logic signal is 1, β inv_i β is the output value of the constant current controller in the inverter-side control system. inv_γ This is the output value of the constant extinguishing arc angle controller.

[0086] S230, obtain the constant extinction arc angle control command value.

[0087] S240, calculate the arc extinction angle compensation.

[0088] Furthermore, the formula for calculating the arc extinction angle compensation amount Δγ in step S240 is as follows:

[0089]

[0090] Where, γ cal This is the theoretical value of the arc extinction angle. γ is the commutation voltage offset angle. ref tri1 is the control command value for the arc extinction angle; tri2 is the enable signal for dynamic compensation of the arc extinction angle.

[0091] Further, in step S210, obtaining the commutation voltage offset angle after the occurrence of an asymmetrical fault includes:

[0092] S211, acquire the three-phase imbalance detection signal.

[0093] Furthermore, step S211, which involves acquiring the three-phase imbalance detection signal, specifically includes the following steps:

[0094] S211a, obtain the phase voltage of the three-phase AC bus;

[0095] S211b, determine whether the sum of the phase voltages of the three-phase AC bus is greater than the three-phase unbalance detection setting value;

[0096] S211c, if so, then the value of the three-phase imbalance detection signal is determined to be 1;

[0097] S211d, if not, then the value of the three-phase imbalance detection signal is determined to be 0.

[0098] S212, obtain the minimum value of AC bus line voltage amplitude and the rated value of AC bus line voltage amplitude.

[0099] Furthermore, in step S212, obtaining the minimum value of the AC bus line voltage amplitude includes:

[0100] S212a, obtain the sampled value of AC bus line voltage.

[0101] S212b uses a second-order generalized integrator to construct voltage sine and cosine components to extract the AC bus line voltage sampling value, thus obtaining the AC bus line voltage amplitude.

[0102] S212c, obtain the minimum value of AC bus line voltage amplitude.

[0103] S213, calculate the commutation voltage offset angle based on the three-phase unbalance detection signal.

[0104] Furthermore, the formula for calculating the commutation voltage offset angle in step S213 is as follows:

[0105]

[0106] Wherein, function f max is the maximum value holding function, and tri1 is the three-phase imbalance detection signal.

[0107] Accordingly, a second aspect of the present invention provides an electronic device, including: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by a processor, the instructions being executed by the processor to cause the at least one processor to perform the above-described continuous commutation failure suppression method based on dynamic compensation of arc extinction angle.

[0108] This invention aims to protect a method for suppressing continuous commutation failure based on dynamic compensation of the arc-extinguishing angle, comprising the following steps: obtaining the theoretical value of the arc-extinguishing angle at which commutation failure does not occur during fault recovery; calculating the arc-extinguishing angle compensation amount based on the theoretical value; and combining the arc-extinguishing angle dynamic compensation enable signal with the arc-extinguishing angle to add the arc-extinguishing angle compensation amount to the fixed arc-extinguishing angle control command value to obtain the fixed arc-extinguishing angle control correction value, thereby suppressing continuous commutation failure during fault recovery. The above technical solution has the following effects:

[0109] By considering the constraints of electrical parameters such as DC current, commutation voltage amplitude, and commutation voltage offset angle on the arc extinction angle during fault recovery, the arc extinction angle is theoretically calculated. By comparing the above calculation results with the rated arc extinction angle, the dynamic compensation amount of the arc extinction angle can be obtained. This arc extinction angle compensation amount is more accurate and does not depend on simulation tuning. It can maintain a high power transmission level of the system while suppressing continuous commutation loss during fault recovery.

[0110] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0111] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0112] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0113] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A method for suppressing continuous commutation failure based on dynamic compensation of arc extinction angle, characterized in that, Includes the following steps: Obtain the theoretical value of the arc extinction angle during fault recovery without commutation failure; Based on the theoretical value of the arc extinction angle, calculate the arc extinction angle compensation amount; By combining the arc extinction angle dynamic compensation enable signal, the arc extinction angle compensation amount is superimposed on the fixed arc extinction angle control command value to obtain the fixed arc extinction angle control correction value, so as to suppress continuous commutation failures during the fault recovery process; The calculation of the arc-extinguishing angle compensation amount based on the theoretical value of the arc-extinguishing angle includes: Obtain the commutation voltage offset angle after an asymmetrical fault occurs; Obtain the dynamic compensation enable signal for the arc extinction angle; Obtain the control command value for the extinguishing arc angle; Calculate the arc extinction angle compensation amount; The arc extinction angle compensation amount is: : ； in, The theoretical value of the arc-extinguishing angle is given. The commutation voltage offset angle is... The value of the fixed extinguishing arc angle control command; This is the enable signal for dynamic compensation of the arc extinction angle; The acquisition of the dynamic compensation enable signal for the arc extinction angle includes: Acquire the first logic signal, the second logic signal, and the third logic signal; Perform an AND operation on the first logic signal, the second logic signal, and the third logic signal to obtain the arc extinction angle dynamic compensation enable signal; Among them, when U N - U ≤ U set2 When, the value of the first logic signal is 0, when U N - U > U set2 At that time, the value of the first logic signal is 1 and the second preset time is extended. U N This refers to the rated amplitude of the AC bus line voltage. U This is the minimum value of the AC bus line voltage amplitude. U set2 This is the voltage drop detection setting value; Among them, when γ min When ≤0, the value of the second logic signal is 0; when γ min When the value is greater than 0, the value of the second logic signal is 1, representing the minimum measured value of the arc extinction angle. γ min ; Among them, when β inv_i ≤ β inv_γ When, the value of the third logic signal is 0, when β inv_i > β inv_γ At that time, the value of the third logic signal is 1. β inv_i The output value of the constant current controller in the inverter-side control system. β inv_γ This is the output value of the constant extinguishing arc angle controller.

2. The continuous commutation failure suppression method based on dynamic compensation of arc extinction angle according to claim 1, characterized in that, The theoretical value of the arc-extinguishing angle is: ； in, β N To trigger the lead angle rating, X For equivalent commutation reactance, k This refers to the primary and secondary turns ratio of the converter transformer. I dc This is the DC current filter value.

3. The continuous commutation failure suppression method based on dynamic compensation of arc extinction angle according to claim 1, characterized in that, The process of obtaining the commutation voltage offset angle after an asymmetric fault occurs includes: Acquire the three-phase imbalance detection signal; Obtain the minimum value of AC bus line voltage amplitude and the rated value of AC bus line voltage amplitude; The commutation voltage offset angle is calculated based on the three-phase imbalance detection signal.

4. The continuous commutation failure suppression method based on dynamic compensation of arc extinction angle according to claim 3, characterized in that, The commutation voltage offset angle is: ； Among them, the function f max is the maximum value holding function, and tri1 is the three-phase imbalance detection signal.

5. The continuous commutation failure suppression method based on dynamic compensation of arc extinction angle according to claim 3, characterized in that, The acquisition of the three-phase imbalance detection signal includes: Obtain the phase voltage of the three-phase AC bus; Determine whether the sum of the phase voltages of the three-phase AC bus is greater than the three-phase imbalance detection setting value; If so, the value of the three-phase imbalance detection signal is determined to be 1; If not, then the value of the three-phase imbalance detection signal is determined to be 0.

6. The continuous commutation failure suppression method based on dynamic compensation of arc extinction angle according to claim 3, characterized in that, The process of obtaining the minimum value of the AC bus line voltage amplitude includes: Obtain the sampled value of the AC bus line voltage; The AC bus line voltage sampling value is extracted by constructing voltage sine and cosine components using a second-order generalized integrator to obtain the AC bus line voltage amplitude. Obtain the minimum value of the AC bus line voltage amplitude.

7. An electronic device, characterized in that, include: At least one processor; And a memory connected to the at least one processor; wherein the memory stores instructions executable by the processor, the instructions being executed by the processor to cause the at least one processor to perform the continuous commutation failure suppression method based on dynamic compensation of arc extinction angle as described in any one of claims 1-6.

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