A high-frequency equivalent circuit control method and system based on converter valve simulation

Abstract

The present invention discloses a high-frequency equivalent circuit control method and system based on converter valve simulation, which belongs to the technical field of converter transformer simulation. The prior art lacks an equivalent model that can accurately simulate the converter valve and valve arm in actual operating conditions, resulting in the inability to accurately simulate the high-frequency current and voltage signals generated by the shutdown of the converter valve and valve arm. A high-frequency equivalent circuit control method based on converter valve simulation of the present invention, by constructing a pulse triggering control model, a pulse triggering signal generation model, and a high-frequency equivalent model of the converter valve, fully considers the propagation process and time-frequency domain characteristics of the high-frequency signal, and couples the effects of capacitors and inductors to perform high-frequency modeling on one or more valve arms in the converter valve, thereby accurately simulating the converter valve and valve arm in actual operating conditions, thereby accurately simulating the high-frequency current and voltage signals generated by the shutdown of the converter valve and valve arm, which is conducive to the promotion and use of converter valves.

Description

Technical Field

[0001] The invention relates to a high-frequency equivalent circuit control method and system based on converter valve simulation, belonging to the technical field of converter transformer simulation. Background Art

[0002] UHV converter valves are key core equipment in HVDC transmission projects and play a pivotal role in converter substations. Whether the converter valves can operate normally directly affects the reliability level of the power grid.

[0003] Compared with traditional AC transformers, converter valves are subjected to complex power frequency AC, harmonic and DC composite electric fields during operation. In addition, due to the wide variety of power equipment in the station and the complex electromagnetic environment, the voltage on both sides of the converter valve changes dramatically under the action of capacitors and inductors, which will inevitably lead to sudden changes in the accompanying current and form pulsating interference with high energy and multiple frequency components. The pulsating interference generated by the converter valve on the DC side spreads to the DC overhead line through the bushing, smoothing reactor and busbar. On the AC side, the pulsating interference is transmitted to the AC busbar through the bushing and converter valve.

[0004] Furthermore, because the time-frequency domain characteristics of the pulsating interference signal are extremely similar to the partial discharge pulse signal, the weak partial discharge signal is more difficult to be identified, which seriously affects the accuracy of the online detection of the partial discharge signal. In addition, for the converter valve, the periodic pulsating interference generated by the conduction and shutdown of the valve arm is the main source of electromagnetic interference. Therefore, it is necessary to simulate and analyze the high-frequency current and time-frequency domain characteristics generated by the converter valve and the valve arm during operation.

[0005] The simulation model in the prior art is usually used to simulate and model high-voltage direct current transmission, and use the simulation model to simulate direct current faults, study the impact of the trigger angle and arc extinction angle on the entire high-voltage direct current transmission system, and calculate parameters such as steady-state tides. Therefore, the prior art lacks an equivalent model that can accurately simulate the converter valve and valve arm in actual operating conditions, resulting in the inability to accurately simulate the high-frequency current and voltage signals generated by the shutdown of the converter valve and valve arm, which is not conducive to the promotion and use of the converter valve.

[0006] Furthermore, the existing technology lacks an operation simulation model for the converter valve and valve arm, and thus cannot analyze the generation mechanism and time-frequency domain characteristics of the pulsating interference signals in its high-frequency current and voltage signals, thereby affecting the accurate detection of partial discharge signals.

[0007] The information disclosed in this Background Art is only for understanding the background of the inventive concept and therefore it may include information that does not constitute the prior art. Summary of the invention

[0008] In response to the above problem or one of the above problems, an object of the present invention is to provide a high-frequency equivalent circuit control method based on converter valve simulation. By constructing a pulse triggering control model, a pulse triggering signal generation model, and a high-frequency equivalent model of the converter valve, the propagation process and time-frequency domain characteristics of the high-frequency signal are fully considered, and the effects of coupling capacitors and inductors are coupled to perform high-frequency modeling on one or more valve arms in the converter valve. Therefore, the converter valve and valve arm in actual operating conditions can be accurately simulated, so that the high-frequency current and voltage signals generated by the shutdown of the converter valve and the valve arm can be accurately simulated, and the high-frequency equivalent circuit control based on the converter valve simulation can be accurately realized, which is conducive to the promotion and use of converter valves.

[0009] In response to the above problem or one of the above problems, the second object of the present invention is to provide a high-frequency equivalent circuit control method based on converter valve simulation. By constructing a single-valve arm high-frequency equivalent unit, a multi-valve arm high-frequency equivalent model, a converter valve high-frequency equivalent model, a phase-locked loop simulation unit, and a pulse trigger signal generation model, the propagation process and time-frequency domain characteristics in the high-frequency signal conduction loop are simulated, and the frequency upper limit of the simulation circuit is significantly improved. It can accurately simulate and study the transmission characteristics of high-frequency current and voltage signals and pulsating high-frequency interference signals within a frequency range of up to 1 MHz.

[0010] In response to the above problem or one of the above problems, the third object of the present invention is to provide a high-frequency equivalent circuit control system based on converter valve simulation. By setting a pulse trigger control module, a pulse trigger signal generating module, and a converter valve high-frequency equivalent module, the propagation process and time-frequency domain characteristics of the high-frequency signal are fully considered, and the effects of coupling capacitors and inductors are used to perform high-frequency modeling on one or more valve arms in the converter valve. Therefore, the converter valve and valve arm in actual operating conditions can be accurately simulated, so that the high-frequency current and voltage signals generated by the shutdown of the converter valve and the valve arm can be accurately simulated.

[0011] To achieve one of the above purposes, the first technical solution of the present invention is:

[0012] A high-frequency equivalent circuit control method based on converter valve simulation includes the following contents:

[0013] Through the pre-built pulse trigger control model, the phase vector technology is used to convert the input grid-side voltage signal into a ramp signal; the ramp signal can represent the phase information of the input grid-side voltage signal;

[0014] Using a pre-built pulse trigger signal generation model, a pulse trigger signal is generated according to the ramp signal and based on a level state change mechanism;

[0015] The pre-built high-frequency equivalent model of the converter valve is used to process the pulse trigger signal to obtain high-frequency current and voltage signals with pulsating interference signals;

[0016] The high-frequency equivalent model of the converter valve is used to simulate the generation process of high-frequency current and voltage signals in the high-voltage direct current transmission system. It performs high-frequency modeling on one or more valve arms in the converter valve based on the propagation process and time-frequency domain characteristics of the high-frequency signal and the effects of coupling capacitors and inductors.

[0017] After continuous exploration and experiments, the present invention constructs a pulse trigger control model, a pulse trigger signal generation model, and a high-frequency equivalent model of the converter valve, fully considers the propagation process and time-frequency domain characteristics of the high-frequency signal, and couples the effects of capacitors and inductors to perform high-frequency modeling on one or more valve arms in the converter valve. Therefore, the converter valve and valve arm in actual operating conditions can be accurately simulated, so as to accurately simulate the high-frequency current and voltage signals generated by the shutdown of the converter valve and the valve arm, and can accurately realize high-frequency equivalent circuit control based on converter valve simulation, which is conducive to the promotion and use of converter valves.

[0018] Furthermore, the present invention can obtain high-frequency current and voltage signals with pulsating interference signals, so that the generation mechanism and time-frequency domain characteristics of the pulsating interference signals in the high-frequency current and voltage signals can be analyzed, which is conducive to the accurate detection of partial discharge signals.

[0019] As the preferred technical measures:

[0020] The method of converting the input grid-side voltage signal into a ramp signal by using the pre-built pulse trigger control model and phase vector technology is as follows:

[0021] Use phase vector technology to build a phase-locked loop simulation unit;

[0022] Inputting a grid-side voltage signal at one side of the phase-locked loop simulation unit;

[0023] The input grid-side voltage signal is a three-phase AC voltage signal, which is processed by a phase-locked loop simulation unit to obtain a fundamental phase angle signal;

[0024] The fundamental wave phase angle signal is input into the converter valve, and according to the phase relationship of the M pulses of the converter valve, it is increased by 60 degrees one by one through the adder to obtain M groups of conversion signals;

[0025] The M groups of transformed signals are then input into the angle-radian converter to obtain the ramp signal reference phase. Figure 1 ;

[0026] Then obtain M groups of transformation signals and input them into the angle radian converter to obtain the ramp signal reference phase Figure 2 ;

[0027] Based on the ramp signal reference phase Figure 1 and ramp signal reference phase Figure 2 , and obtain N groups of ramp signals.

[0028] As the preferred technical measures:

[0029] The method of constructing a phase-locked loop simulation unit using phase vector technology is as follows:

[0030] According to the phase vector technology, a phase detector, a low-pass filter and a voltage-controlled oscillator are provided and electrically connected in sequence to form a phase-locked loop simulation unit;

[0031] Or / and, the method of obtaining the fundamental phase angle signal after being processed by the phase-locked loop simulation unit is as follows:

[0032] The three-phase AC voltage signal is used as an input signal and input into a phase detector, which outputs a voltage signal by comparing the phase of the input signal with the output signal of the voltage-controlled oscillator;

[0033] Then the voltage signal is input into a low-pass filter to filter out the high-frequency components and noise in the voltage signal, leaving only the low-frequency component signal;

[0034] The low-frequency component signal is then input into a voltage-controlled oscillator to lock the phase of the low-frequency component signal and the input signal to obtain a fundamental wave phase angle signal.

[0035] As the preferred technical measures:

[0036] Using the pre-built pulse trigger signal generation model, the method for generating a pulse trigger signal according to the ramp signal and based on the level state change mechanism is as follows:

[0037] According to the linear change characteristics of the ramp signal, a ramp threshold for triggering a level state change is set;

[0038] Based on the ramp threshold, create H groups of pulse trigger signal generators;

[0039] Each group of pulse trigger signal generators includes a first input terminal, a second input terminal and a third input terminal;

[0040] Divide the N groups of ramp signals into H groups and input them into H first input terminals respectively;

[0041] Based on the ramp signal, N groups of trigger angle settings are set, and the N groups of trigger angle settings are divided into H groups, and are input into H second input terminals respectively;

[0042] Each third input terminal is connected to a single-input comparator, and based on the N groups of ramp signals, N groups of comparison signals are obtained;

[0043] Inputting N groups of comparison signals into a pulse trigger signal generator, so that the ramp signal can be converted into N groups of pulse waveforms with equal phase intervals, thereby obtaining N groups of pulse trigger signals; the period of the pulse trigger signal is related to the rate of change of the ramp signal and the ramp threshold setting;

[0044] Or / and, the method of constructing the high-frequency equivalent model of the converter valve is as follows:

[0045] According to the technical characteristics of the high-voltage direct current transmission system and taking into account the effects of coupling capacitors and inductors, a high-frequency modeling of the single valve arm of the converter valve is carried out to obtain a high-frequency equivalent unit of the single valve arm, which is used to simulate the high-frequency characteristics of the pulsating interference signal generated by the thyristor shutdown under a single valve arm.

[0046] According to the single valve arm high frequency equivalent unit, a multi-valve arm high frequency equivalent model is built to simulate the high frequency characteristics of the M pulsation converter valve group;

[0047] The H multi-valve arm high-frequency equivalent models are coupled to obtain a high-frequency equivalent model of the converter valve, which is used to simulate the high-frequency characteristics of the converter valve.

[0048] The value of M is 3 or 6 or 9 or 12, the value of H is 2 or 3 or 4 or 5, and the corresponding value of N is M*H.

[0049] Preferably, the value of M is 6, the value of H is 2, and the value of N is 12.

[0050] As the preferred technical measures:

[0051] Based on N groups of ramp signals, the method of obtaining N groups of comparison signals is as follows:

[0052] Divide N groups of ramp signals into H groups and input them into H single-input comparators respectively;

[0053] If the value of the ramp signal exceeds the ramp threshold, the single-input comparator outputs a high level value;

[0054] If the value of the ramp signal is lower than the ramp threshold, the single-input comparator outputs a low-level value;

[0055] The high level value or the low level value is used as a comparison signal to determine N groups of comparison signals.

[0056] The ramp threshold is 308.45.

[0057] As the preferred technical measures:

[0058] The method to obtain the high-frequency equivalent unit of a single valve arm is as follows:

[0059] Based on the propagation process and time-frequency domain characteristics of high-frequency signals and the specific structure of the converter valve arm, a broadband structure is used to represent the saturated reactor, thyristor and RC circuit components.

[0060] According to the dynamic characteristics of the saturated reactor under the operating conditions, the saturated reactor is regarded as a linear element in the transient process, and the high-frequency equivalent impedance of the saturated reactor is calculated;

[0061] According to the characteristics of the converter valve and the high-frequency equivalent impedance of the saturated reactor, the stray capacitance between the positive and negative electrodes of the thyristor, the internal resistance and internal inductance of the thyristor when it is turned on, and the equalizing resistance and equalizing capacitance of the RC circuit components are calculated and determined;

[0062] The high-frequency equivalent impedance, stray capacitance, internal resistance and internal inductance as well as the voltage-equalizing resistance and voltage-equalizing capacitance are electrically connected to obtain a single valve arm high-frequency equivalent unit;

[0063] Based on the generation process of interference signals in the HVDC transmission system, the single valve arm high frequency equivalent unit is placed in an open state or a closed state, so that the stray capacitance and the voltage-sharing capacitance in the single valve arm high frequency equivalent unit are charged and discharged, generating high frequency current and voltage signals, and realizing high frequency simulation of the converter valve.

[0064] Or / and, the method of building a high-frequency equivalent model of a multi-valve arm is as follows:

[0065] A high-frequency circuit model is established by connecting multiple single-valve arm high-frequency equivalent units in series and parallel;

[0066] One side of the high-frequency circuit model is connected to the converter transformer to obtain a high-frequency equivalent model of a multi-valve arm;

[0067] Converter transformers are used to convert AC power into DC power.

[0068] As the preferred technical measures:

[0069] The method of using the pre-built high-frequency equivalent model of the converter valve to process the pulse trigger signal to obtain the high-frequency current and voltage signals is as follows:

[0070] Obtaining a number of single valve arm high-frequency equivalent units in the converter valve high-frequency equivalent model;

[0071] A plurality of single valve arm high frequency equivalent units are respectively input with a pulse trigger signal, so that the plurality of single valve arm high frequency equivalent units are triggered to conduct;

[0072] After being turned on, the stray capacitance and voltage-sharing capacitance inside the high-frequency equivalent unit of the single valve arm are charged and discharged, and several high-frequency current and voltage signals are output;

[0073] According to a plurality of high-frequency current and voltage signals, a plurality of pulsating interference signals are obtained, and high-frequency equivalent simulation of the plurality of pulsating interference signals is realized.

[0074] To achieve one of the above purposes, the second technical solution of the present invention is:

[0075] A high-frequency equivalent circuit control method based on converter valve simulation includes the following contents:

[0076] Based on the structure of the converter valve and valve arm, the propagation process of high-frequency signals, and the time-frequency domain characteristics, a single valve arm high-frequency equivalent unit is built;

[0077] M single valve arm high frequency equivalent units are connected in series and parallel to construct a multi-valve arm high frequency equivalent model;

[0078] H multi-valve arm high-frequency equivalent models are connected in series to obtain a converter valve high-frequency equivalent model;

[0079] Generate a ramp signal through a phase-locked loop simulation unit;

[0080] The ramp signal is converted into a pulse trigger signal by using a pulse trigger signal generation model;

[0081] The pulse trigger signal is input into the high-frequency equivalent model of the converter valve to obtain high-frequency current and voltage signals; and the pulsation interference signal is obtained according to the high-frequency current and voltage signals.

[0082] The present invention simulates the propagation process and time-frequency domain characteristics in the high-frequency signal conduction loop by constructing a single-valve arm high-frequency equivalent unit, a multi-valve arm high-frequency equivalent model, a converter valve high-frequency equivalent model, a phase-locked loop simulation unit, and a pulse trigger signal generation model, thereby significantly improving the upper frequency limit of the simulation circuit and being able to accurately simulate and study the transmission characteristics of high-frequency current and voltage signals and pulsating high-frequency interference signals within a frequency range of up to 1 MHz.

[0083] At the same time, the pulse trigger control loop proposed in the present invention has built an accurate single valve arm high-frequency equivalent unit, which can accurately simulate the high-frequency current and voltage signals of the converter valve and the valve arm, and is more in line with the pulsating interference signal generated by the actual high-voltage direct current transmission converter station.

[0084] To achieve one of the above purposes, the third technical solution of the present invention is:

[0085] A high-frequency equivalent circuit control system based on converter valve simulation includes a pulse trigger control module, a pulse trigger signal generation module and a converter valve high-frequency equivalent module:

[0086] The pulse trigger control module is used to convert the input grid-side voltage signal into a ramp signal by using a phase vector technology; the ramp signal can represent the phase information of the input grid-side voltage signal;

[0087] A pulse trigger signal generating module, used for generating a pulse trigger signal according to the ramp signal and based on a level state change mechanism;

[0088] The high-frequency equivalent module of the converter valve is used to simulate the generation process of high-frequency current and voltage signals in the high-voltage direct current transmission system. It performs high-frequency modeling on one or more valve arms in the converter valve according to the propagation process and time-frequency domain characteristics of the high-frequency signal and the effects of coupling capacitors and inductors; and can process the pulse trigger signal to obtain high-frequency current and voltage signals and pulsation interference signals.

[0089] After continuous exploration and experiments, the present invention sets a pulse trigger control module, a pulse trigger signal generating module, and a converter valve high-frequency equivalent module, fully considers the propagation process and time-frequency domain characteristics of the high-frequency signal, and couples the effects of capacitors and inductors to perform high-frequency modeling on one or more valve arms in the converter valve. Therefore, the converter valve and valve arm in actual operating conditions can be accurately simulated, so that the high-frequency current and voltage signals generated by the shutdown of the converter valve and the valve arm can be accurately simulated, which is conducive to the promotion and use of the converter valve.

[0090] As the preferred technical measures:

[0091] The pulse trigger control module is provided with a phase-locked loop simulation unit; the phase-locked loop simulation unit includes a phase detector, a low-pass filter and a voltage-controlled oscillator;

[0092] or / and, a pulse trigger signal generating module, comprising H groups of pulse trigger signal generators;

[0093] Each group of pulse trigger signal generators includes a first input terminal for receiving a ramp signal, a second input terminal for receiving a trigger angle setting, and a third input terminal for connecting a single-input comparator;

[0094] Or / and, the converter valve high-frequency equivalent module includes one or H series-connected multi-valve arm high-frequency equivalent modules;

[0095] Each multi-valve arm high-frequency equivalent module is provided with M single-valve arm high-frequency equivalent units for simulating the high-frequency characteristics of the converter valve group;

[0096] The single valve arm high frequency equivalent unit includes a saturated reactor, a thyristor and a resistor-capacitor circuit component, and is used to simulate the high frequency characteristics of the pulsating interference signal generated by the turn-off of the thyristor under a single valve arm.

[0097] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0098] After continuous exploration and experiments, the present invention constructs a pulse trigger control model, a pulse trigger signal generation model, and a high-frequency equivalent model of the converter valve, fully considers the propagation process and time-frequency domain characteristics of the high-frequency signal, and couples the effects of capacitors and inductors to perform high-frequency modeling on one or more valve arms in the converter valve. Therefore, the converter valve and valve arm in actual operating conditions can be accurately simulated, so as to accurately simulate the high-frequency current and voltage signals generated by the shutdown of the converter valve and the valve arm, and can accurately realize high-frequency equivalent circuit control based on converter valve simulation, which is conducive to the promotion and use of converter valves.

[0099] Furthermore, the present invention simulates the propagation process and time-frequency domain characteristics in the high-frequency signal conduction loop by constructing a single-valve arm high-frequency equivalent unit, a multi-valve arm high-frequency equivalent model, a converter valve high-frequency equivalent model, a phase-locked loop simulation unit, and a pulse trigger signal generation model, thereby significantly improving the upper frequency limit of the simulation circuit and being able to accurately simulate and study the transmission characteristics of high-frequency current and voltage signals and pulsating high-frequency interference signals within a frequency range of up to 1 MHz.

[0100] Furthermore, after continuous exploration and experimentation, the present invention has fully considered the propagation process and time-frequency domain characteristics of high-frequency signals by setting a pulse trigger control module, a pulse trigger signal generating module, and a converter valve high-frequency equivalent module, and coupled the effects of capacitors and inductors to perform high-frequency modeling on one or more valve arms in the converter valve. Therefore, the converter valve and valve arm in actual operating conditions can be accurately simulated, so that the high-frequency current and voltage signals generated by the shutdown of the converter valve and the valve arm can be accurately simulated, which is conducive to the promotion and use of converter valves. BRIEF DESCRIPTION OF THE DRAWINGS

[0101] Figure 1 A flow chart of a high-frequency equivalent circuit control method based on converter valve simulation of the present invention;

[0102] Figure 2 A schematic diagram of a circuit structure of a single valve arm high frequency equivalent unit of the present invention;

[0103] Figure 3 A schematic diagram of a circuit structure of a high-frequency equivalent model of a multi-valve arm of the present invention;

[0104] Figure 4 A schematic diagram of the structure of a phase-locked loop simulation unit of the present invention;

[0105] Figure 5 A schematic diagram of a ramp signal reference phase diagram of the present invention;

[0106] Figure 6 A schematic diagram of a circuit structure of a pulse trigger signal generator of the present invention;

[0107] Figure 7A schematic diagram of a single group of pulse trigger signals of the present invention;

[0108] Figure 8 A time domain waveform diagram after the single valve arm of the converter valve is simulated by the present invention;

[0109] Fig. 9 This is a spectrum diagram after the single valve arm of the converter valve is simulated by the present invention. DETAILED DESCRIPTION

[0110] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0111] On the contrary, the present invention covers any substitution, modification, equivalent method and scheme made on the essence and scope of the present invention as defined by the claims. Further, in order to make the public have a better understanding of the present invention, some specific details are described in detail in the following detailed description of the present invention. Those skilled in the art can fully understand the present invention without the description of these details.

[0112] Unless otherwise defined, all technical and scientific terms used in the present invention have the same meaning as those commonly understood by those skilled in the art to which the present invention belongs. The terms used in the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "or / and" used in the present invention includes any and all combinations of one or more of the related listed items.

[0113] like Figure 1 As shown, the first specific embodiment of the high-frequency equivalent circuit control method based on converter valve simulation of the present invention is:

[0114] A high-frequency equivalent circuit control method based on converter valve simulation includes the following contents:

[0115] Through the pre-built pulse trigger control model, the phase vector technology is used to convert the input grid-side voltage signal into a ramp signal; the ramp signal can represent the phase information of the input grid-side voltage signal;

[0116] Using a pre-built pulse trigger signal generation model, a pulse trigger signal is generated according to the ramp signal and based on a level state change mechanism;

[0117] The pre-built high-frequency equivalent model of the converter valve is used to process the pulse trigger signal to obtain high-frequency current and voltage signals with pulsating interference signals;

[0118] The high-frequency equivalent model of the converter valve is used to simulate the generation process of high-frequency current and voltage signals in the high-voltage direct current transmission system. It performs high-frequency modeling on one or more valve arms in the converter valve based on the propagation process and time-frequency domain characteristics of the high-frequency signal and the effects of coupling capacitors and inductors.

[0119] In this embodiment, the method of converting the input grid-side voltage signal into a ramp signal by using a pre-built pulse trigger control model and a phase vector technology is as follows:

[0120] Use phase vector technology to build a phase-locked loop simulation unit;

[0121] Inputting a grid-side voltage signal at one side of the phase-locked loop simulation unit;

[0122] The input grid-side voltage signal is a three-phase AC voltage signal, which is processed by a phase-locked loop simulation unit to obtain a fundamental phase angle signal;

[0123] The fundamental phase angle signal is input into the converter valve, and according to the phase relationship of the 6 pulses of the converter valve, it is increased by 60 degrees one by one through the adder to obtain 6 groups of conversion signals;

[0124] The six sets of transformed signals are then input into the angle-radian converter to obtain the reference phase of the ramp signal. Figure 1 ;

[0125] Then obtain 6 sets of transformation signals and input them into the angle radian converter to obtain the ramp signal reference phase Figure 2 ;

[0126] Based on the ramp signal reference phase Figure 1 and ramp signal reference phase Figure 2 , and get 12 groups of ramp signals.

[0127] In this embodiment: the method of constructing a phase-locked loop simulation unit using phase vector technology is as follows:

[0128] According to the phase vector technology, a phase detector, a low-pass filter and a voltage-controlled oscillator are provided and electrically connected in sequence to form a phase-locked loop simulation unit;

[0129] In this embodiment: the method for obtaining the fundamental phase angle signal after being processed by the phase-locked loop simulation unit is as follows:

[0130] The three-phase AC voltage signal is used as an input signal and input into a phase detector, which outputs a voltage signal by comparing the phase of the input signal with the output signal of the voltage-controlled oscillator;

[0131] Then the voltage signal is input into a low-pass filter to filter out the high-frequency components and noise in the voltage signal, leaving only the low-frequency component signal;

[0132] The low-frequency component signal is then input into a voltage-controlled oscillator to lock the phase of the low-frequency component signal and the input signal to obtain a fundamental wave phase angle signal.

[0133] In this embodiment: using the pre-built pulse trigger signal generation model, according to the ramp signal and based on the level state change mechanism, the method for generating the pulse trigger signal is as follows:

[0134] According to the linear change characteristics of the ramp signal, a ramp threshold for triggering a level state change is set;

[0135] Based on the ramp threshold, two sets of pulse trigger signal generators are created;

[0136] Each group of pulse trigger signal generators includes a first input terminal, a second input terminal and a third input terminal;

[0137] Divide the 12 groups of ramp signals into two groups and input them into two first input terminals respectively;

[0138] Based on the ramp signal, 12 groups of trigger angle settings are set, and the 12 groups of trigger angle settings are divided into two groups, and are input into two second input terminals respectively;

[0139] Each third input terminal is connected to a single-input comparator, and based on the 12 groups of ramp signals, 12 groups of comparison signals are obtained;

[0140] The 12 groups of comparison signals are input into the pulse trigger signal generator, so that the ramp signal can be converted into 12 groups of pulse waveforms with equal phase intervals, thereby obtaining 12 groups of pulse trigger signals; the period of the pulse trigger signal is related to the change rate of the ramp signal and the ramp threshold setting;

[0141] In this embodiment: the method for constructing the high-frequency equivalent model of the converter valve is as follows:

[0142] According to the technical characteristics of the high-voltage direct current transmission system and taking into account the effects of coupling capacitors and inductors, a high-frequency modeling of the single valve arm of the converter valve is carried out to obtain a high-frequency equivalent unit of the single valve arm, which is used to simulate the high-frequency characteristics of the pulsating interference signal generated by the thyristor shutdown under a single valve arm.

[0143] According to the single valve arm high-frequency equivalent unit, a multi-valve arm high-frequency equivalent model is built to simulate the high-frequency characteristics of the 12-pulse converter valve group;

[0144] A high-frequency equivalent model of a converter valve is constructed using a multi-valve arm high-frequency equivalent model; or, two multi-valve arm high-frequency equivalent models are coupled to obtain a high-frequency equivalent model of a converter valve, which is used to simulate the high-frequency characteristics of a 24-pulsation converter valve.

[0145] In this embodiment, the method of obtaining 12 groups of comparison signals based on 12 groups of ramp signals is as follows:

[0146] Divide the 12 groups of ramp signals into two groups and input them into two single-input comparators respectively;

[0147] If the value of the ramp signal exceeds the ramp threshold, the single-input comparator outputs a high level value;

[0148] If the value of the ramp signal is lower than the ramp threshold, the single-input comparator outputs a low-level value;

[0149] The high level value or the low level value is used as a comparison signal to determine 12 groups of comparison signals.

[0150] In this embodiment: the method for obtaining the single valve arm high frequency equivalent unit is as follows:

[0151] Based on the propagation process and time-frequency domain characteristics of high-frequency signals, and according to the specific structure of the converter valve and valve arm, a broadband structure is used to represent the saturated reactor, thyristor and RC circuit components;

[0152] According to the dynamic characteristics of the saturated reactor under the operating conditions, the saturated reactor is regarded as a linear element in the transient process, and the high-frequency equivalent impedance of the saturated reactor is calculated;

[0153] According to the characteristics of the converter valve and the high-frequency equivalent impedance of the saturated reactor, the stray capacitance between the positive and negative electrodes of the thyristor, the internal resistance and internal inductance of the thyristor when it is turned on, and the equalizing resistance and equalizing capacitance of the RC circuit components are calculated and determined;

[0154] The high-frequency equivalent impedance, stray capacitance, internal resistance and internal inductance as well as the voltage-equalizing resistance and voltage-equalizing capacitance are electrically connected to obtain a single valve arm high-frequency equivalent unit;

[0155] Based on the generation process of interference signals in the HVDC transmission system, the single valve arm high frequency equivalent unit is placed in an open state or a closed state, so that the stray capacitance and the voltage-sharing capacitance in the single valve arm high frequency equivalent unit are charged and discharged, generating high frequency current and voltage signals, and realizing high frequency simulation of the converter valve.

[0156] In this embodiment: the method of building a high-frequency equivalent model of a multi-valve arm is as follows:

[0157] Six single-valve-arm high-frequency equivalent units are connected in series and parallel to establish a high-frequency circuit model;

[0158] One side of the high-frequency circuit model is connected to the converter transformer to obtain a high-frequency equivalent model of a multi-valve arm;

[0159] Converter transformers are used to convert AC power into DC power.

[0160] In this embodiment, a method of using a pre-built high-frequency equivalent model of a converter valve to process a pulse trigger signal to obtain high-frequency current and voltage signals is as follows:

[0161] Obtain 6 single valve arm high frequency equivalent units in the converter valve high frequency equivalent model;

[0162] A pulse trigger signal is input into each of the six single-valve-arm high-frequency equivalent units, so that the six single-valve-arm high-frequency equivalent units are triggered to conduct; after the six single-valve-arm high-frequency equivalent units are conducted, the stray capacitance and the voltage-equalizing capacitance inside the single-valve-arm high-frequency equivalent units are charged and discharged to generate high-frequency current, and six high-frequency current and voltage signals are output.

[0163] After the six single-valve-arm high-frequency equivalent units are closed, the stray capacitance and voltage-equalizing capacitance inside the single-valve-arm high-frequency equivalent units are charged and discharged again, and six high-frequency current and voltage signals are output.

[0164] According to the 12 high-frequency current and voltage signals, 12 pulse interference signals can be obtained, realizing the high-frequency equivalent simulation of multi-pulse interference signals.

[0165] A second specific embodiment of the high-frequency equivalent circuit control method based on converter valve simulation of the present invention:

[0166] A high-frequency equivalent circuit control method based on converter valve simulation includes the following contents:

[0167] According to the technical characteristics of the high-voltage direct current transmission system, a 12-pulse converter valve group was built, and a 12-pulse pulse trigger control structure was established. The effects of coupling capacitors and inductors were considered, and high-frequency modeling of the single valve arm of the converter valve was performed. The upper frequency limit of the model was significantly improved, so that the high-frequency characteristics of the pulsating interference signal generated by the shutdown of the thyristor under a single valve arm can be accurately simulated.

[0168] The HVDC transmission system consists of a primary system and a secondary control system. The primary system is the electrical connection structure of the HVDC transmission system, i.e., the circuit structure, and the secondary control system is the structure that controls its operation.

[0169] The present invention firstly proposes a new single-valve-arm high-frequency equivalent unit based on the ±500kV high-voltage direct current transmission CIGRE standard model; and applies it to build a multi-valve-arm high-frequency equivalent model of a 6-pulsation converter valve group; then, based on the multi-valve-arm high-frequency equivalent model, a converter valve high-frequency equivalent model of a 12-pulsation valve group is built; and then, according to the converter valve high-frequency equivalent model, a pulse triggering control model and a pulse triggering signal generation model of the 12-pulsation valve group are built, so that the 12-pulsation valve group can be triggered and operated normally, thereby simulating the propagation of the 12-pulsation interference signal.

[0170] The 6-pulse converter valve group is a component of the entire high-voltage direct current transmission simulation model, and the pulse trigger control system can generate a trigger pulse signal so that the equivalent circuit of the 6-pulse converter valve group can work normally.

[0171] In this embodiment, the method of building a single valve arm high frequency equivalent unit is as follows:

[0172] The single valve arm high frequency equivalent unit is a high frequency construction of the converter valve in the entire high voltage direct current transmission system. The final output of the single valve arm high frequency equivalent unit is the high frequency current and voltage signal of the single valve arm of a single pulsating converter valve.

[0173] When the converter valve is in the short process of being opened or closed, the voltage across its two ends rises or falls rapidly, and the stray capacitance and buffer capacitance inside the converter valve are charged and discharged, which will generate high-frequency current. Therefore, according to the specific structure of the converter valve arm, the saturated reactor, thyristor, and RC circuit components are all represented by a broadband structure to form a broadband model of the converter valve. The actual saturated reactor has a complex structure and is a nonlinear element, but according to the dynamic characteristics exhibited by its operating conditions, it can be regarded as a linear element in the transient process. The present invention represents the high-frequency structure of the saturated reactor with a series-parallel circuit consisting of resistors, inductors, and capacitors to simplify it as follows: Figure 2 The high frequency structure shown. Figure 2 It is a single valve arm high frequency equivalent unit. Figure 2 In It represents the high-frequency equivalent impedance of the saturated reactor; is the stray capacitance between the cathode and cathode of the thyristor; It is an intercrystalline tube (there are internal resistance and internal inductance when it is turned on); and Respectively represent the voltage-equalizing resistor and the voltage-equalizing capacitor; It is a voltage-equalizing capacitor and also plays a role in voltage equalization. The stray capacitance between the cathode and cathode of the thyristor The calculation formula is as follows:

[0174]

[0175] Where: , , , are fixed constants respectively; , , ; ; is the voltage across the thyristor.

[0176] Considering In this embodiment, Use a fixed value of 4.23nF.

[0177] like Figure 3 As shown, in this embodiment, the method of building a high-frequency equivalent model of a multi-valve arm is as follows:

[0178] According to the typical 6-pulse rectifier structure, the single valve arm high-frequency equivalent units are connected in series and parallel to establish a multi-valve arm high-frequency equivalent model. Figure 3 , Figure 3 In is the stray capacitance between the cathode and cathode of the thyristor; It is an intercrystalline tube, which has internal resistance and internal inductance when it is turned on; and Respectively represent the voltage-equalizing resistor and the voltage-equalizing capacitor; It is a voltage-equalizing capacitor, among which FP11, FP21, FP31, FP41, FP51, and FP61 are gate pulses, which are used to input pulse trigger signals to trigger the 6-pulse rectifier to turn on and operate normally. The left side of the converter valve is connected to the converter transformer, which can play a rectifying role and convert the three-phase (ABC) AC power into DC power.

[0179] like Figure 4 As shown, in this embodiment, the method of using the phase-locked loop control to generate the ramp signal reference phase diagram of the pulse trigger control model is as follows:

[0180] The internal structure of the phase-locked loop element is composed of three parts: a phase detector, a low-pass filter, and a voltage-controlled oscillator. The ramp signal is a linearly changing signal. The phase detector outputs a voltage signal by comparing the phase of the input signal and the output signal of the voltage-controlled oscillator. The function of the low-pass filter is to filter out the high-frequency components and noise in the three-phase voltage input to the phase detector, and only retain the low-frequency components. The output signal of the voltage-controlled oscillator maintains a specific phase relationship with the input signal to lock the phase. The phase vector technology is used to generate a ramp signal to match the phase of the target signal with the phase of the input signal, and to match the phase of the input three-phase voltage signal. The working principle of the phase-locked loop to generate a ramp signal is as follows:

[0181] Set the input signal for:

[0182]

[0183] in, is the three-phase input voltage signal, is the input voltage frequency, t is the time, is the initial phase of the input signal.

[0184] Voltage controlled oscillator output signal for:

[0185]

[0186] in, is the voltage controlled oscillator output voltage signal, is the output voltage frequency of the voltage controlled oscillator, t is the time, is the initial phase of the voltage controlled oscillator output signal, and The two are unified into , then the signal is transformed into:

[0187]

[0188]

[0189] In the above formula, Indicates the initial phase of the input signal after rewriting. It represents the difference between the output signal angular frequency and the oscillator signal angular frequency. For the convenience of calculation, the phase Unified Indicates that the voltage-controlled oscillator output signal is rewritten as:

[0190]

[0191] in, Represents the voltage-controlled oscillator output signal after rewriting.

[0192] The initial phase detector multiplies the input signal and the output signal of the voltage-controlled oscillator to obtain the following expression:

[0193]

[0194] The output signal is obtained by filtering out the high frequency components through a low pass filter , and its relevant calculation formula is as follows:

[0195]

[0196]

[0197]

[0198] In the formula, is a constant, is the initial phase of the output signal, is a fixed gain factor.

[0199] According to the limit definition, when When I was very young, Approximately , especially when When ≤30°, a ramp signal can be obtained , its expression is as follows;

[0200]

[0201] The specific ramp signal generation method is as follows:

[0202] First, input the stable three-phase AC voltage signals Va, Vb, and Vc on the grid side to the left side of the phase-locked loop (PLL). After passing through the phase-locked loop, the fundamental phase angle thetaDR of phase a can be obtained in degrees. Then, according to the phase relationship of the pulses of the converter valve 6, the adder adds 60 degrees one by one to obtain six new phase angle signals, including phase angle signal thetaD10, phase angle signal thetaD20, phase angle signal thetaD30, phase angle signal thetaD40, phase angle signal thetaD50, and phase angle signal thetaD60. After passing through the angle radian converter, six groups of conversion signals are obtained, including conversion signal thetaD1, conversion signal thetaD2, conversion signal thetaD3, conversion signal thetaD4, conversion signal thetaD5, and conversion signal thetaD6, and then the ramp signal reference phase diagram can be output, as shown in Figure 5 shown.

[0203] In this embodiment, the method of constructing a pulse trigger signal generator by generating a pulse trigger signal model is as follows:

[0204] like Figure 6 As shown, the pulse trigger signal generator includes port H, port L, and port Dblck.

[0205] Port H inputs 6 groups of ramp signals generated by the phase-locked oscillator, and port L inputs 6 groups of trigger angle constants AOR, which can be set to a fixed value of 10 degrees. The input side of port Dblck is connected to a single-input comparator, with input signal KBR and input parameter as time. This component sets the time as the input threshold, and releases the blockade when the simulation running time exceeds the default time value.

[0206] The ramp signal is converted into a pulse trigger signal. The pulse trigger circuit principle used is the comparator method, that is, monitoring the change of the signal. The high and low levels of the square wave are output according to the preset threshold value, and the maximum value of the ramp signal is set to , and set the ramp threshold to , Therefore, the comparator threshold value set in this embodiment, that is, the ramp threshold value is 308.45. Usually, a suitable level can be selected so that the state change can be triggered when the ramp signal exceeds or falls below the level.

[0207] The ramp signal is usually represented by a linearly changing voltage signal. The ramp signal output by the phase-locked oscillator increases linearly with time. If the value of the ramp signal exceeds the threshold, the comparator outputs a high level value. If the value of the ramp signal is lower than the threshold, the comparator outputs a low level value. The period of the pulse trigger signal is related to the rate of change of the ramp signal and the threshold setting. The signal outputs 6 groups of pulse waveforms with equal phase intervals. The pulse waveform is connected to the thyristor. The duration of the pulse trigger signal set in the present invention is 0.005s. The pulse trigger signal can be found in Figure 7 .

[0208] The terminal voltage waveform and spectrum of one valve arm during the switching process of the converter valve in rated operation are obtained through simulation calculation, as shown in Figure 8 and Fig. 9 As shown. It can be seen that the spectrum after Fourier transform processing can show high-frequency characteristics above 500kHz, and then according to Figure 8 By observing the voltage mutation in the circuit, we can get the specific pulsation interference signal.

[0209] A third specific embodiment of the high-frequency equivalent simulation method of the present invention:

[0210] A high-frequency equivalent circuit control method based on converter valve simulation includes the following contents:

[0211] Step 1: Considering the high-frequency characteristics of the converter valve, a single valve arm high-frequency equivalent unit is constructed;

[0212] Step 2, build a high-frequency equivalent model of the converter valve based on the single-valve-arm high-frequency equivalent unit; the single-valve-arm high-frequency equivalent unit is a part of the 6-pulse rectifier valve group in the single-stage 12-pulse valve group. The 6-pulse rectifier valve group has a total of 6 valve arms, and the single-valve-arm high-frequency equivalent unit is used to simulate one of the valve arms.

[0213] Step 3: Build a pulse trigger control model and use a phase-locked loop to convert the input grid-side voltage into a ramp reference phase signal;

[0214] Step 4, input the ramp signal and the trigger angle signal into the pulse trigger signal generation model to generate a pulse trigger signal, so that the 12-pulse converter is turned on, and the ramp signal can represent the phase information of the input grid-side voltage.

[0215] Therefore, the present invention forms a high-frequency equivalent conduction loop model that can accurately simulate the 12-pulse converter valve group of high-voltage direct current transmission by constructing a pulse trigger control model, a pulse trigger signal generation model, and a high-frequency equivalent model of the converter valve. It fully considers the generation process of the high-frequency 12-pulse interference signal generated by the thyristor switching on and off in the high-voltage direct current transmission system, simulates the propagation process and time-frequency domain characteristics in the high-frequency signal conduction loop, and significantly improves the upper frequency limit of the model. It can accurately simulate and study the transmission characteristics of the 12-pulse high-frequency interference signal within a frequency range of up to 1 MHz.

[0216] The pulse trigger control loop proposed in the present invention has built an accurate single valve arm high-frequency equivalent unit, which can accurately simulate the high-frequency current and voltage signals of the single valve arm of the 6-pulse converter valve, and is more in line with the 12-pulse interference signal generated by the actual high-voltage direct current transmission converter station.

[0217] A system embodiment using the method of the present invention:

[0218] A high-frequency equivalent circuit control system based on converter valve simulation includes a pulse trigger control module, a pulse trigger signal generation module and a converter valve high-frequency equivalent module:

[0219] The pulse trigger control module is used to convert the input grid-side voltage signal into a ramp signal by using a phase vector technology; the ramp signal can represent the phase information of the input grid-side voltage signal;

[0220] A pulse trigger signal generating module, used for generating a pulse trigger signal according to the ramp signal and based on a level state change mechanism;

[0221] The high-frequency equivalent module of the converter valve is used to process the pulse trigger signal to obtain high-frequency current and voltage signals, and can simulate the 12-pulse interference signal generated by the high-voltage DC transmission converter station.

[0222] In this embodiment: the pulse trigger control module is provided with a phase-locked loop simulation unit; the phase-locked loop simulation unit includes a phase detector, a low-pass filter, and a voltage-controlled oscillator.

[0223] In this embodiment: the pulse trigger signal generating module includes two groups of pulse trigger signal generators; each group of pulse trigger signal generators includes a first input terminal for receiving a ramp signal, a second input terminal for receiving a trigger angle constant, and a third input terminal for connecting a single-input comparator.

[0224] In this embodiment: the converter valve high-frequency equivalent module includes one or two multi-valve arm high-frequency equivalent models connected in series;

[0225] Each multi-valve arm high-frequency equivalent model is equipped with six single-valve arm high-frequency equivalent units, which are used to simulate the high-frequency characteristics of the 12-pulse converter valve group; the single-valve arm high-frequency equivalent unit includes a saturated reactor, a thyristor and a resistor-capacitor circuit component, which is used to simulate the high-frequency characteristics of the pulsating interference signal generated by the shutdown of the thyristor under a single valve arm.

[0226] An embodiment of a device applying the method of the present invention:

[0227] An electronic device comprising:

[0228] one or more processors;

[0229] A storage device for storing one or more programs;

[0230] When the one or more programs are executed by the one or more processors, the one or more processors implement the above-mentioned high-frequency equivalent circuit control method based on converter valve simulation.

[0231] A computer medium embodiment using the method of the present invention:

[0232] A computer-readable storage medium stores a computer program, which, when executed by a processor, implements the above-mentioned high-frequency equivalent circuit control method based on converter valve simulation.

[0233] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, and computer program products. Therefore, the present application may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the present application may take the form of a computer program product implemented on one or more computer-usable storage media containing computer-usable program code.

[0234] The present application is described by flowcharts or / and block diagrams of the methods, devices (systems), and computer program products of the embodiments of the present application. It should be understood that each process or / and block in the flowchart or / and block diagram and the combination of the processes or / and blocks in the flowchart or / and block diagram can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart or / and block diagram. Figure 1 Process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0235] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 Process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0236] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 Process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0237] The model in this application is an object that objectively describes the morphological structure with the help of physical or virtual representation. The object is not equal to the object and is not limited to physical and virtual. It can be a data processing function, software program, processing mode, usage method, operation method, workflow, application process, electronic hardware, circuit module, processing system, system imitation or simulation object.

[0238] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field can still modify or replace the specific implementation methods of the present invention with equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A high-frequency equivalent circuit control method based on converter valve simulation, characterized in that: Includes the following: Through the pre-built pulse trigger control model, the phase vector technology is used to convert the input grid-side voltage signal into a ramp signal; the ramp signal can represent the phase information of the input grid-side voltage signal; Using a pre-built pulse trigger signal generation model, a pulse trigger signal is generated according to the ramp signal and based on a level state change mechanism; The pre-built high-frequency equivalent model of the converter valve is used to process the pulse trigger signal to obtain high-frequency current and voltage signals with pulsating interference signals; The high-frequency equivalent model of the converter valve is used to simulate the generation process of high-frequency current and voltage signals in the high-voltage direct current transmission system. It performs high-frequency modeling on one or more valve arms in the converter valve based on the propagation process and time-frequency domain characteristics of the high-frequency signal and the effects of coupling capacitors and inductors.

2. A high-frequency equivalent circuit control method based on converter valve simulation according to claim 1, characterized in that: The method of converting the input grid-side voltage signal into a ramp signal by using the pre-built pulse trigger control model and phase vector technology is as follows: Use phase vector technology to build a phase-locked loop simulation unit; Inputting a grid-side voltage signal at one side of the phase-locked loop simulation unit; The input grid-side voltage signal is a three-phase AC voltage signal, which is processed by a phase-locked loop simulation unit to obtain a fundamental phase angle signal; The fundamental wave phase angle signal is input into the converter valve, and according to the phase relationship of the M pulses of the converter valve, it is increased by 60 degrees one by one through the adder to obtain M groups of conversion signals; The M groups of transformed signals are then input into the angle-radian converter to obtain a ramp signal reference phase diagram 1; Then, M groups of transformation signals are obtained and input into the angle-radian converter to obtain the second reference phase diagram of the ramp signal; Based on the ramp signal reference phase diagram 1 and the ramp signal reference phase diagram 2, N groups of ramp signals are obtained.

3. A high-frequency equivalent circuit control method based on converter valve simulation according to claim 2, characterized in that: The method of constructing a phase-locked loop simulation unit using phase vector technology is as follows: According to the phase vector technology, a phase detector, a low-pass filter and a voltage-controlled oscillator are provided and electrically connected in sequence to form a phase-locked loop simulation unit; Or / and, the method of obtaining the fundamental phase angle signal after being processed by the phase-locked loop simulation unit is as follows: The three-phase AC voltage signal is used as an input signal and input into a phase detector, which outputs a voltage signal by comparing the phase of the input signal with the output signal of the voltage-controlled oscillator; Then the voltage signal is input into a low-pass filter to filter out the high-frequency components and noise in the voltage signal, leaving only the low-frequency component signal; The low-frequency component signal is then input into a voltage-controlled oscillator to lock the phase of the low-frequency component signal and the input signal to obtain a fundamental wave phase angle signal.

4. The high-frequency equivalent circuit control method based on converter valve simulation according to claim 1, characterized in that: Using the pre-built pulse trigger signal generation model, the method for generating a pulse trigger signal according to the ramp signal and based on the level state change mechanism is as follows: According to the linear change characteristics of the ramp signal, a ramp threshold for triggering a level state change is set; Based on the ramp threshold, create H groups of pulse trigger signal generators; Each group of pulse trigger signal generators includes a first input terminal, a second input terminal and a third input terminal; Divide the N groups of ramp signals into H groups and input them into H first input terminals respectively; Based on the ramp signal, N groups of trigger angle settings are set, and the N groups of trigger angle settings are divided into H groups, and are input into H second input terminals respectively; Each third input terminal is connected to a single-input comparator, and based on the N groups of ramp signals, N groups of comparison signals are obtained; Inputting N groups of comparison signals into a pulse trigger signal generator, so that the ramp signal can be converted into N groups of pulse waveforms with equal phase intervals, thereby obtaining N groups of pulse trigger signals; the period of the pulse trigger signal is related to the rate of change of the ramp signal and the ramp threshold setting; Or / and, the method of constructing the high-frequency equivalent model of the converter valve is as follows: According to the technical characteristics of the high-voltage direct current transmission system and taking into account the effects of coupling capacitors and inductors, a high-frequency modeling of the single valve arm of the converter valve is carried out to obtain a high-frequency equivalent unit of the single valve arm, which is used to simulate the high-frequency characteristics of the pulsating interference signal generated by the thyristor shutdown under a single valve arm. According to the single valve arm high frequency equivalent unit, a multi-valve arm high frequency equivalent model is built to simulate the high frequency characteristics of the M pulsation converter valve group; The H multi-valve arm high-frequency equivalent models are coupled to obtain a high-frequency equivalent model of the converter valve, which is used to simulate the high-frequency characteristics of the converter valve.

5. A high-frequency equivalent circuit control method based on converter valve simulation according to claim 4, characterized in that: Based on N groups of ramp signals, the method of obtaining N groups of comparison signals is as follows: Divide N groups of ramp signals into H groups and input them into H single-input comparators respectively; If the value of the ramp signal exceeds the ramp threshold, the single-input comparator outputs a high level value; If the value of the ramp signal is lower than the ramp threshold, the single-input comparator outputs a low-level value; The high level value or the low level value is used as a comparison signal to determine N groups of comparison signals.

6. A high-frequency equivalent circuit control method based on converter valve simulation according to claim 4, characterized in that: The method to obtain the high-frequency equivalent unit of a single valve arm is as follows: Based on the propagation process and time-frequency domain characteristics of high-frequency signals and the specific structure of the converter valve arm, a broadband structure is used to represent the saturated reactor, thyristor and RC circuit components. According to the dynamic characteristics of the saturated reactor under the operating conditions, the saturated reactor is regarded as a linear element in the transient process, and the high-frequency equivalent impedance of the saturated reactor is calculated; According to the characteristics of the converter valve and the high-frequency equivalent impedance of the saturated reactor, the stray capacitance between the positive and negative electrodes of the thyristor, the internal resistance and internal inductance of the thyristor when it is turned on, and the equalizing resistance and equalizing capacitance of the RC circuit components are calculated and determined; The high-frequency equivalent impedance, stray capacitance, internal resistance and internal inductance as well as the voltage-equalizing resistance and voltage-equalizing capacitance are electrically connected to obtain a single valve arm high-frequency equivalent unit; Based on the generation process of interference signals in the HVDC transmission system, the single valve arm high frequency equivalent unit is placed in an open state or a closed state, so that the stray capacitance and the voltage-sharing capacitance in the single valve arm high frequency equivalent unit are charged and discharged, generating high frequency current and voltage signals, and realizing high frequency simulation of the converter valve. Or / and, the method of building a high-frequency equivalent model of a multi-valve arm is as follows: A high-frequency circuit model is established by connecting multiple single-valve arm high-frequency equivalent units in series and parallel; One side of the high-frequency circuit model is connected to the converter transformer to obtain a high-frequency equivalent model of a multi-valve arm; Converter transformers are used to convert AC power into DC power.

7. A high-frequency equivalent circuit control method based on converter valve simulation according to claim 6, characterized in that: The method of using the pre-built high-frequency equivalent model of the converter valve to process the pulse trigger signal to obtain the high-frequency current and voltage signals is as follows: Obtaining a number of single valve arm high-frequency equivalent units in the converter valve high-frequency equivalent model; A plurality of single valve arm high frequency equivalent units are respectively input with a pulse trigger signal, so that the plurality of single valve arm high frequency equivalent units are triggered to conduct; After being turned on, the stray capacitance and voltage-sharing capacitance inside the high-frequency equivalent unit of the single valve arm are charged and discharged, and several high-frequency current and voltage signals are output; According to a plurality of high-frequency current and voltage signals, a plurality of pulsating interference signals are obtained, and high-frequency equivalent simulation of the plurality of pulsating interference signals is realized.

8. A high-frequency equivalent circuit control method based on converter valve simulation, characterized in that: Includes the following: Based on the structure of the converter valve arm, the propagation process of the high-frequency signal and the time-frequency domain characteristics, a single valve arm high-frequency equivalent unit is built; M single valve arm high frequency equivalent units are connected in series and parallel to construct a multi-valve arm high frequency equivalent model; H multi-valve arm high-frequency equivalent models are connected in series to obtain a converter valve high-frequency equivalent model; Generate a ramp signal through a phase-locked loop simulation unit; The ramp signal is converted into a pulse trigger signal by using a pulse trigger signal generation model; The pulse trigger signal is input into the high-frequency equivalent model of the converter valve to obtain high-frequency current and voltage signals; and the pulsation interference signal is obtained according to the high-frequency current and voltage signals.

9. A high-frequency equivalent circuit control system based on converter valve simulation, characterized in that: It includes pulse trigger control module, pulse trigger signal generation module and converter valve high frequency equivalent module: The pulse trigger control module is used to convert the input grid-side voltage signal into a ramp signal by using a phase vector technology; the ramp signal can represent the phase information of the input grid-side voltage signal; A pulse trigger signal generating module, used for generating a pulse trigger signal according to the ramp signal and based on a level state change mechanism; The high-frequency equivalent module of the converter valve is used to simulate the generation process of high-frequency current and voltage signals in the high-voltage direct current transmission system. It performs high-frequency modeling on one or more valve arms in the converter valve according to the propagation process and time-frequency domain characteristics of the high-frequency signal and the effects of coupling capacitors and inductors; and can process the pulse trigger signal to obtain high-frequency current and voltage signals and pulsation interference signals.

10. A high-frequency equivalent circuit control system based on converter valve simulation according to claim 9, characterized in that: The pulse trigger control module is provided with a phase-locked loop simulation unit; the phase-locked loop simulation unit includes a phase detector, a low-pass filter and a voltage-controlled oscillator; or / and, a pulse trigger signal generating module, comprising H groups of pulse trigger signal generators; Each group of pulse trigger signal generators includes a first input terminal for receiving a ramp signal, a second input terminal for receiving a trigger angle setting, and a third input terminal for connecting a single-input comparator; Or / and, the converter valve high-frequency equivalent module includes one or H series-connected multi-valve arm high-frequency equivalent modules; Each multi-valve arm high-frequency equivalent module is provided with M single-valve arm high-frequency equivalent units for simulating the high-frequency characteristics of the converter valve group; The single valve arm high frequency equivalent unit includes a saturated reactor, a thyristor and a resistor-capacitor circuit component, and is used to simulate the high frequency characteristics of the pulsating interference signal generated by the turn-off of the thyristor under a single valve arm.

Images