Transformer short-circuit fault current limiting device and capacitor maintenance management method in device

Abstract

The invention provides a transformer short-circuit fault current limiting device and a capacitor maintenance management method in the device. The transformer short-circuit fault current limiting device comprises a main branch, a current limiting branch, a modulation inductor, an artificial zero-crossing branch and an energy consumption detection branch. The main branch is provided with a vacuum quick switch which is connected in series between the bus and the primary side port of the transformer; the current-limiting branch is provided with a current-limiting reactor which is connected in parallel with the vacuum quick switch. The artificial zero-crossing branch is connected in series with the modulation inductor and then is connected in parallel with the current-limiting branch, and the artificial zero-crossing branch comprises an energy-storage capacitor bank module and a vacuum trigger switch which are connected in series. In the application, when the fault current on the main branch is detected, the vacuum quick switch is firstly controlled to be switched off, and then the vacuum trigger switch is controlled to be switched on, so that the vacuum quick switch can be switched on and off conveniently; furthermore, the vacuum trigger switch is controlled to be turned off, the current limiting reactor is connected between the power distribution system bus and the transformer, short-circuit fault current limiting is achieved, and damage to the transformer when the load is short-circuited is reduced.

Description

Technical Field

[0001] This invention relates to the field of transformer fault current limiting technology, and more specifically, to a transformer short-circuit fault current limiting device and a capacitor maintenance and management method in the device. Background Technology

[0002] Transformers are the hub of the power grid for transmitting electrical energy and are the main equipment for grid operation. When a power transformer winding is short-circuited, especially when the load is short-circuited, the huge electromagnetic force generated by the fault current can cause great damage to the transformer winding.

[0003] Currently, by monitoring the current flowing through the main branch lines between the power distribution system busbar and the transformer, it is possible to determine whether a short-circuit fault has occurred. To effectively isolate the hazards posed by short-circuit faults, vacuum fast-acting switches are installed on the main branch lines. During normal transformer operation, the vacuum fast-acting switch remains closed. When a fault current is detected by the current transformer, the vacuum circuit breaker is controlled to open, thereby disconnecting the connection between the transformer and the power distribution system busbar.

[0004] However, transformers are usually connected to multiple loads at their output terminals. To maintain power supply stability and to facilitate phase and line selection for fault location, transformers need to continue operating under fault conditions. Summary of the Invention

[0005] To facilitate the reduction of damage to transformers during load short circuits, this application provides a transformer short-circuit fault current limiting device and a capacitor maintenance and management method within the device.

[0006] Firstly, this application provides a transformer short-circuit fault current limiting device, which adopts the following technical solution: A transformer short-circuit fault current limiting device includes a main branch, a current limiting branch, an energy absorbing branch, a modulation inductor, an artificial zero-crossing branch, and an energy consumption detection branch. Vacuum fast switches are connected in series between the busbar and the primary side port of the transformer on the main branch line; A current-limiting reactor connected in parallel to the vacuum fast switch is provided on the current-limiting branch; The energy-absorbing branch is connected in series with the modulation inductor and then in parallel with the current-limiting branch. A nonlinear resistor group is provided on the energy-absorbing branch, which is composed of multiple zinc oxide resistors connected in series and parallel. The artificial zero-crossing branch is connected in parallel to the energy-absorbing branch, and the artificial zero-crossing branch includes an energy storage capacitor bank module and a vacuum trigger switch connected in series. The energy consumption detection branch is connected in parallel to the energy storage capacitor bank module. The energy consumption detection branch includes a switch selection module, an energy consumption resistor, and an energy consumption inductor connected in series.

[0007] Optionally, the energy storage capacitor bank module includes a zero-crossing energy storage capacitor, a first switching transistor, a zero-crossing backup capacitor, and a second switching transistor. The zero-crossing energy storage capacitor is connected in series with the switching transistor to form a first zero-crossing energy storage submodule; The zero-crossing backup capacitor is connected in series with the second switch to form a second zero-crossing energy storage submodule, and the first zero-crossing submodule and the second zero-crossing submodule are connected in parallel. The switch selection module includes a first energy-consuming bidirectional thyristor and a second energy-consuming bidirectional thyristor. The input terminal of the first energy-consuming bidirectional thyristor is electrically connected to the input terminal of the first switch, and the output terminal of the first energy-consuming bidirectional thyristor is electrically connected to the end of the energy-consuming resistor furthest from the energy-consuming resistor. The input terminal of the second energy-consuming bidirectional thyristor is electrically connected to the input terminal of the second switching transistor, and the output terminal of the second energy-consuming bidirectional thyristor is electrically connected to the output terminal of the first energy-consuming bidirectional thyristor.

[0008] Optionally, the transformer short-circuit fault current limiting device further includes a controller, multiple current transformers, and multiple voltage transformers. The current transformers are respectively installed on the main branch, current limiting branch, energy absorption branch, artificial zero crossing branch and energy consumption detection branch, and multiple current transformers are respectively connected in parallel to the zero crossing energy storage capacitor and the zero crossing backup capacitor. The controller has multiple input terminals that are electrically connected to the output terminals of multiple current transformers and multiple voltage transformers, respectively; the controller has multiple control terminals that are electrically connected to the control terminals of the vacuum fast switch, the vacuum trigger switch, the first switch tube, the second switch tube, the first energy-consuming bidirectional thyristor, and the second energy-consuming bidirectional thyristor, respectively.

[0009] Secondly, this application provides a capacitor maintenance and management method in a transformer short-circuit fault current limiting device, which adopts the following technical solution: A capacitor maintenance and management method in a transformer short-circuit fault current limiting device, the method comprising: Upon receiving the capacitance detection command, control switch one and energy-consuming bidirectional thyristor one are turned on; The energy storage voltage across the zero-crossing energy storage capacitor and the energy consumption current flowing through the energy consumption detection branch are acquired in real time. When the energy storage voltage across the zero-crossing energy storage capacitor is equal to the preset voltage detection threshold, the first switch and the first energy-consuming bidirectional thyristor are turned off, and the discharge detection duration of the zero-crossing energy storage capacitor is recorded. The current energy storage capacity of the zero-crossing energy storage capacitor is generated based on the preset initial energy storage voltage of the zero-crossing energy storage capacitor, the voltage detection threshold, the real-time energy consumption current value, and the discharge detection duration. Based on the pre-input standard recorded capacity of the zero-crossing energy storage capacitor and the current energy storage capacity, the estimated service life of the zero-crossing energy storage capacitor is generated.

[0010] Optionally, generating the current energy storage capacity of the zero-crossing energy storage capacitor based on the preset initial energy storage voltage of the zero-crossing energy storage capacitor, the voltage detection threshold, and the real-time acquired energy consumption current value includes: A capacitor voltage difference is generated based on the initial energy storage voltage of the zero-crossing energy storage capacitor and the voltage detection threshold. The current stored charge of the zero-crossing energy storage capacitor is calculated based on the multiple energy consumption current values ​​and the discharge detection duration. The current energy storage capacity of the zero-crossing energy storage capacitor is calculated based on the current stored charge and the voltage difference of the capacitor.

[0011] Optionally, the controller also contains capacitor temperature-varying capacity data, which includes mutually mapped capacitance change coefficients and temperature values. The step of generating the estimated lifespan of the zero-crossing energy storage capacitor based on the pre-input standard recorded capacity of the zero-crossing energy storage capacitor and the current energy storage capacity includes: Obtain the current ambient temperature of the zero-crossing energy storage capacitor; Based on the capacitor temperature change capacitance data and the current ambient temperature, match the corresponding current capacitance change coefficient; The current capacitor aging capacity is calculated based on the capacitance change coefficient and the current energy storage capacity. The estimated lifespan of the zero-crossing energy storage capacitor is generated based on the current aging capacity of the capacitor and the pre-input standard recorded capacity.

[0012] Optionally, the controller pre-stores capacitor aging data of the zero-crossing energy storage capacitor, the capacitor aging data including multiple experimental aging times and corresponding multiple experimental aging capacitor capacities. The step of generating the estimated lifespan of the zero-crossing energy storage capacitor based on the current capacitor aging capacity and the pre-input standard recorded capacity includes: Based on the current capacitor aging capacity, the corresponding target experimental aging capacitor capacity is matched in the capacitor aging data. An aging comparison coefficient is generated based on the target experimental aging time corresponding to the target experimental aging capacitor capacity and the current usage time of the zero-crossing energy storage capacitor. The estimated service life is calculated based on the preset aging capacitor capacity threshold and the aging comparison coefficient.

[0013] Optionally, the method further includes: If the current energy storage capacity is less than the preset continuous use threshold of the capacitor, then the estimated adjustment voltage is calculated and generated based on the current energy storage capacity, the standard recorded capacity, and the initial energy storage voltage. Compare the estimated adjustment voltage with the preset voltage adjustment threshold of the zero-crossing energy storage capacitor; If the estimated adjustment voltage is less than or equal to the voltage adjustment threshold, then the initial energy storage voltage of the zero-crossing energy storage capacitor is updated according to the estimated adjustment voltage. If the estimated adjustment voltage is greater than the voltage adjustment threshold, then based on the redundant capacitance value of the redundant spare capacitor connected in parallel with the zero-crossing energy storage capacitor, a common adjustment voltage value for the zero-crossing energy storage capacitor and the redundant spare capacitor is generated, and the initial energy storage voltage of the zero-crossing energy storage capacitor is updated according to the adjustment voltage value.

[0014] Optionally, the step of calculating and generating the estimated regulation voltage based on the current storage capacity, the standard recorded capacity, and the initial energy storage voltage includes: Obtain the historical ambient temperature information of the zero-crossing energy storage capacitor and filter out the historical ambient temperature peaks; Based on the historical peak ambient temperature, the capacitor temperature change capacitance data, and the current capacitor aging capacitance value, an estimated baseline storage capacity value is generated. A zero-crossing current reference value is generated based on the standard recorded capacity, the initial energy storage voltage, and the inductive reactance value of the modulation inductor. Based on the zero-crossing current reference value and the estimated baseline energy storage capacitor value, the estimated regulation voltage is calculated and generated.

[0015] Optionally, generating the common adjustable voltage value of the zero-crossing storage capacitor and the redundant backup capacitor based on the redundant capacitor value connected in parallel with the zero-crossing energy storage capacitor includes: The redundant capacitor value and the estimated baseline storage capacity value are used to calculate a joint estimated storage capacity value. Based on the zero-crossing current and the jointly estimated storage capacitor value, the common adjustable voltage value of the zero-crossing reserve capacitor and the standby capacitor is calculated and generated.

[0016] In summary, this application includes at least one of the following beneficial technical effects: When the current value fed back by the current transformer on the main branch is detected as the fault current, the vacuum fast switch is controlled to open. When the vacuum fast switch reaches the effective opening distance, the vacuum trigger switch is controlled to turn on. At this time, under the action of the energy storage capacitor module and the modulation inductor, a high-frequency resonant current is superimposed on the vacuum fast switch, thereby creating an artificial zero crossing on the vacuum fast switch, so that the vacuum arc-extinguishing chamber of the vacuum fast switch can extinguish the arc at zero crossing, so as to realize the opening of the vacuum fast switch. At the same time, the fault current is transferred to the artificial zero crossing branch, and then the fault current is transferred to the energy absorption branch. Further, the vacuum trigger switch is controlled to turn off. At this point, the current limiting reactor is connected between the distribution system bus and the primary side of the transformer to realize the current limiting of the short circuit fault, thereby reducing the damage to the transformer when the load is short-circuited. By acquiring the energy consumption current value of the zero crossing energy storage capacitor during the discharge detection period and the voltage difference of the zero crossing energy storage capacitor during the discharge detection period in real time, the current energy storage capacity of the zero crossing energy storage capacitor is calculated. Then, based on the current energy storage capacity and the standard recorded capacity, the remaining estimated service life of the zero crossing energy storage capacitor is estimated. Therefore, while performing state detection on the zero-crossing energy storage capacitor, the remaining estimated service life of the zero-crossing energy storage capacitor is also estimated based on its current energy storage capacity, reducing the possibility of failure to address the wear and tear of the zero-crossing energy storage capacitor in a timely manner. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a circuit diagram of a transformer short-circuit fault current limiting device provided in an embodiment of this application.

[0018] Figure 2 This is a flowchart illustrating the capacitor maintenance and management process in a transformer short-circuit fault current limiting device provided in this application embodiment.

[0019] Figure 3 This is a schematic diagram of a process for generating an estimated lifespan of a zero-crossing energy storage capacitor, provided in an embodiment of this application.

[0020] Figure 4 This is a schematic diagram of a process for updating the initial energy storage voltage of a zero-crossing energy storage capacitor according to an embodiment of this application.

[0021] Figure 5 This is a schematic diagram of a process for generating an estimated regulating voltage according to an embodiment of this application.

[0022] Figure 6This is a schematic diagram of a process for generating a voltage value to be adjusted jointly by a zero-crossing reserve capacitor and a standby capacitor, provided in an embodiment of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the following will be described in conjunction with the appendix. Figure 1-6 The embodiments of the present invention will be described in further detail below.

[0024] This application provides a transformer short-circuit fault current limiting device, which includes a main branch, a current limiting branch, an energy absorbing branch, a modulation inductor, an artificial zero-crossing branch, and an energy consumption detection branch.

[0025] The main branch circuit and the current-limiting branch circuit are connected in parallel. A vacuum fast switch is installed on the main branch circuit, connected in series between the busbar and the primary side port of the transformer. A current-limiting reactor is installed on the current-limiting branch circuit, connected in parallel with the vacuum fast switch.

[0026] The energy-absorbing branch is connected in series with the modulation inductor and then in parallel with the main branch. Specifically, one end of the energy-absorbing branch is connected to the main branch, the other end of the energy-absorbing branch is connected to the modulation inductor, and the other end of the modulation inductor is connected to the other end of the main branch.

[0027] The artificial zero-crossing branch is connected in parallel with the energy-absorbing branch. The energy-absorbing branch includes a nonlinear resistor group, which is composed of multiple oxidizing resistors connected in series and parallel.

[0028] The manual zero-crossing branch includes an energy storage capacitor bank module and a vacuum trigger switch. The energy storage capacitor bank module includes a zero-crossing energy storage capacitor, a first switch, a zero-crossing backup capacitor, and a second switch.

[0029] The zero-crossing energy storage capacitor is connected in series with the first switching transistor to form the first zero-crossing energy storage submodule; the zero-crossing spare capacitor is connected in series with the second switching transistor to form the second zero-crossing energy storage submodule, and the first zero-crossing submodule and the second zero-crossing submodule are connected in parallel.

[0030] The energy consumption detection branch is connected in parallel to the energy storage capacitor bank module of the artificial zero-crossing branch to detect the capacity of the zero-crossing energy storage capacitor and the zero-crossing backup capacitor.

[0031] Specifically, in this application, switch one and switch two can be MOS transistors, thyristors, etc. In this application, an NMOS transistor is used as an example for illustration, and switch one and switch two are respectively referred to as the first NMOS transistor and the second NMOS transistor.

[0032] One end of the zero-crossing energy storage capacitor is electrically connected to the drain of the first NMOS transistor, the source of the first NMOS transistor is electrically connected to one end of the modulation inductor, one end of the zero-crossing spare capacitor is electrically connected to the drain of the second NMOS transistor, and the source of the second NMOS transistor is electrically connected to the source of the first NMOS transistor.

[0033] The transformer short-circuit fault current limiting device also includes a controller, multiple current transformers, and multiple voltage transformers. Current transformers are respectively installed on the main branch, current limiting branch, energy absorption branch, artificial zero crossing branch and energy consumption detection branch, and multiple current transformers are respectively connected in parallel to the zero crossing energy storage capacitor and the zero crossing standby capacitor. The controller's multiple input terminals are electrically connected to the output terminals of multiple current transformers and multiple voltage transformers, respectively; the controller's multiple control terminals are electrically connected to the control terminals of the vacuum fast switch, vacuum trigger switch, switch tube one, and switch tube two, respectively.

[0034] In this application, when both the transformer and the load are in normal operating condition, the vacuum fast switch remains closed, and the power distribution system busbar is connected to the primary phase of the transformer through the vacuum fast switch.

[0035] When the controller detects that the current value fed back from the current transformer on the main branch is the fault current, it controls the control switch to conduct and simultaneously controls the vacuum fast switch to open. When the vacuum fast switch reaches the effective opening distance, the controller controls the vacuum trigger switch to conduct. At this time, under the action of the zero-crossing energy storage capacitor and the modulation inductor, a high-frequency resonant current is superimposed on the vacuum fast switch, thereby creating an artificial zero-crossing point on the vacuum fast switch, causing the vacuum arc-extinguishing chamber of the vacuum fast switch to extinguish at zero, so as to realize the opening of the vacuum fast switch.

[0036] Simultaneously, the fault current is transferred to the artificial zero-crossing branch and reverse-charges the zero-crossing energy storage capacitor. When the voltage across the zero-crossing energy storage capacitor reaches the conduction voltage of the nonlinear resistor group, the fault current flows into the energy-absorbing branch, which then controls the vacuum trigger switch to turn off. The fault current decays to the milliampere level in an approximately triangular wave form within the nonlinear resistor group. At this point, the current-limiting reactor is connected between the distribution system bus and the primary side of the transformer, achieving current limiting during short-circuit faults.

[0037] The energy consumption detection branch includes a switch selection module, an energy consumption resistor, and an energy consumption inductor, which are connected in series.

[0038] The switch selection module of the energy consumption detection branch includes energy-consuming bidirectional thyristor one and energy-consuming bidirectional thyristor two. The input terminal of energy-consuming bidirectional thyristor one is electrically connected to the input terminal of switch tube one, and the output terminal of energy-consuming bidirectional thyristor one is electrically connected to the end of the energy-consuming resistor that is furthest from the energy-consuming inductor. The input terminal of the second energy-consuming bidirectional thyristor is electrically connected to the input terminal of the second switching transistor, and the output terminal of the second energy-consuming bidirectional thyristor is electrically connected to the output terminal of the second energy-consuming bidirectional thyristor.

[0039] The controller also has control terminals that are electrically connected to the control terminals of energy-consuming bidirectional thyristor one and energy-consuming bidirectional thyristor two, respectively.

[0040] When the vacuum trigger switch is turned off and the zero-crossing energy storage capacitor experiences a reverse voltage increase, the controller can release the reverse voltage stored in the zero-crossing energy storage capacitor by controlling the switch to turn off and the energy-consuming bidirectional thyristor to turn on.

[0041] In this application, it is also possible to detect whether the energy storage capacity of the zero-crossing energy storage capacitor or the zero-crossing reserve capacitor changes by periodically releasing the energy stored in the zero-crossing energy storage capacitor or the zero-crossing reserve capacitor, thereby reducing the impact of excessive aging of the zero-crossing energy storage capacitor or the zero-crossing reserve capacitor.

[0042] In this system, if a decrease in the capacitance of the zero-crossing energy storage capacitor is detected during long-term use, a redundant backup capacitor can be connected in parallel across the capacitor. A third-generation switch is then connected in series between the backup capacitor and the zero-crossing capacitor. This parallel connection of the redundant backup capacitor increases the combined energy storage capacity of the zero-crossing and redundant capacitors. Specifically, taking the third-generation switch as an NMOS transistor (referred to here as the third NMOS transistor), its drain is electrically connected to one end of the zero-crossing energy storage capacitor, its source is electrically connected to one end of the redundant backup capacitor, the other end of the zero-crossing backup capacitor is electrically connected to the other end of the redundant backup capacitor, and one of the controller's control terminals is electrically connected to the gate of the third NMOS transistor.

[0043] This application also provides a capacitor maintenance and management method in a transformer short-circuit fault current limiting device, which is applied to the aforementioned transformer short-circuit fault current limiting device. The main implementer of this method can be the controller in the transformer short-circuit fault current limiting device, and it is further supported by multiple current transformers, multiple voltage transformers, a vacuum fast switch, a vacuum trigger switch, a first switch transistor, a second switch transistor, a first energy-consuming bidirectional thyristor, and a second energy-consuming bidirectional thyristor.

[0044] This application uses the capacity detection of the zero-crossing energy storage capacitor in the transformer short-circuit fault current limiting device as an example for illustration. Other cases, such as the capacity detection of the zero-crossing backup capacitor, are similar and will not be described in detail.

[0045] The following will describe the specific implementation methods. Figure 2 The processing flow shown is explained in detail below: Step S101: After receiving the capacitor detection command, control switch one to turn off and energy-consuming bidirectional thyristor one to turn on.

[0046] In practice, after receiving a capacitor detection command input by the user or periodically triggered by the controller's internal memory, the controller controls the switch to turn off and the energy-consuming bidirectional thyristor to turn on, so that the electrical energy stored in the zero-crossing energy storage capacitor can be released through the energy-consuming resistor and energy-consuming inductor.

[0047] Step S102: Real-time acquisition of the capacitor energy storage voltage across the zero-crossing energy storage capacitor and the energy consumption current value flowing through the energy consumption detection branch.

[0048] During implementation, the controller acquires the capacitor storage voltage across the zero-crossing energy storage capacitor in real time, fed back from the voltage transformer. Simultaneously, the controller acquires the energy consumption current value fed back from the current transformer on the energy consumption detection branch in real time.

[0049] Step S103: When the energy storage voltage across the zero-crossing energy storage capacitor is equal to the preset voltage detection threshold, control the energy-consuming bidirectional thyristor to turn off, and record the discharge detection time of the zero-crossing energy storage capacitor.

[0050] In practice, when the controller detects that the energy storage voltage across the zero-crossing energy storage capacitor is equal to the voltage detection threshold, the controller controls the energy-consuming bidirectional thyristor to turn off, and the zero-crossing energy storage capacitor discharge process ends.

[0051] Meanwhile, the controller records the interval between the turn-on and turn-off of the energy-consuming bidirectional thyristor. This interval is referred to as the discharge detection time.

[0052] Step S104: Generate the current energy storage capacity of the zero-crossing energy storage capacitor based on the preset initial energy storage voltage, voltage detection threshold, real-time energy consumption current value, and discharge detection duration.

[0053] In practice, the controller's memory has a preset initial energy storage voltage for the zero-crossing energy storage capacitor. In the transformer short-circuit fault current limiting device, when the load is running normally, the voltage across the zero-crossing energy storage capacitor needs to be adjusted to the initial energy storage voltage in order to meet the requirement of creating a zero-crossing point in vacuum fast switching.

[0054] The controller uses the real-time energy consumption current value, initial energy storage voltage, and voltage detection threshold to calculate the current storage capacity of the zero-crossing energy storage capacitor.

[0055] Specifically, in step S104, the following operation process also exists: The capacitor voltage difference is generated based on the initial energy storage voltage of the zero-crossing energy storage capacitor and the voltage detection threshold.

[0056] In practice, the controller generates the capacitor voltage difference by subtracting the initial energy storage voltage from the voltage detection threshold.

[0057] Based on multiple energy consumption current values ​​and discharge detection duration, the current stored charge of the generated zero-crossing energy storage capacitor is calculated.

[0058] In implementation, the controller records the discharge detection duration of the zero-crossing energy storage capacitor, and then calculates the amount of energy stored in the zero-crossing energy storage capacitor based on the discharge detection duration and multiple energy consumption current values. Here, the amount of energy stored in the capacitor is referred to as the current amount of energy stored in the capacitor. The formula for calculating the current amount of discharge charge of the capacitor is as follows: ; in, This represents the amount of charge discharged from the capacitor. and These represent the turn-on and turn-off times of the bidirectional thyristor, respectively. This refers to the energy consumption current value flowing through the energy consumption detection branch.

[0059] The current energy storage capacity of the generated zero-crossing energy storage capacitor is calculated based on the current stored charge and voltage difference of the capacitor.

[0060] In practice, the controller calculates the storage capacity of the zero-crossing energy storage capacitor based on the current stored charge and the voltage difference between the capacitors. This storage capacity is referred to as the current storage capacity. The formula for calculating the current storage capacity is as follows: ; in, This is the current capacitor capacity. This represents the voltage change value.

[0061] Step S105: Based on the pre-input standard recorded capacity of the zero-crossing energy storage capacitor and the current energy storage capacity, generate the estimated service life of the zero-crossing energy storage capacitor.

[0062] In practice, the controller uses the voltage difference between the initial and current capacitance of the zero-crossing energy storage capacitor as the capacitance decay.

[0063] The controller also sets an aging capacitor capacity threshold for the zero-crossing energy storage capacitor, and calculates the aging capacitor attenuation threshold using the initial capacitance and the aging capacitor capacity threshold. Then, the controller divides the capacitance attenuation amount by the aging capacitor attenuation threshold to generate the estimated lifespan ratio. Next, it multiplies the estimated lifespan ratio by the time the zero-crossing energy storage capacitor has been in use, and after excluding the time the zero-crossing energy storage capacitor has been in use, it calculates the estimated lifespan of the zero-crossing energy storage capacitor.

[0064] In this application, the controller detects the energy storage capacity of the zero-crossing energy storage capacitor through cyclic processing or by receiving user input control. After receiving the capacitor detection command, the controller controls the switching transistor to turn off and the energy-consuming bidirectional thyristor to turn on, establishing a loop between the zero-crossing energy storage capacitor, the energy-consuming resistor, and the energy-consuming inductor. When the voltage across the zero-crossing energy storage capacitor equals the voltage detection threshold, the controller controls the energy-consuming bidirectional thyristor to turn off, ending the discharge detection process of the zero-crossing energy storage capacitor. Furthermore, by acquiring the energy-consuming current value of the zero-crossing energy storage capacitor during the discharge detection period in real time, as well as the voltage difference during the discharge detection period, the current energy storage capacity of the zero-crossing energy storage capacitor is calculated. Then, based on the current energy storage capacity and the standard recorded capacity, the remaining estimated service life of the zero-crossing energy storage capacitor is estimated. Therefore, while detecting the state of the zero-crossing energy storage capacitor, the remaining estimated service life of the zero-crossing energy storage capacitor is estimated based on its current energy storage capacity, reducing the possibility of failure to address the wear and tear of the zero-crossing energy storage capacitor in a timely manner.

[0065] Optionally, in step S105, there may also be such Figure 3 The process shown also includes capacitor temperature-dependent capacitance data in the controller. This data includes a mapped capacitance change coefficient and a temperature value. The specific operation procedure is as follows: Step S201: Obtain the current ambient temperature of the zero-crossing energy storage capacitor.

[0066] In practice, the controller obtains the current ambient temperature of the environment where the zero-crossing energy storage capacitor is located through a temperature sensor.

[0067] Step S202: Match the corresponding current capacitance change coefficient based on the capacitance temperature change data and the current ambient temperature.

[0068] In practice, the controller uses the current environmental information to match the corresponding capacitance change coefficient in the capacitance temperature change data. The capacitance change coefficient matched here can be called the current capacitance change coefficient.

[0069] Step S203: Calculate and generate the current capacitor aging capacity based on the capacitance change coefficient and the current energy storage capacity.

[0070] In practice, the controller also stores the standard recorded capacity of the zero-crossing energy storage capacitor, which is the energy storage capacity of the zero-crossing energy storage capacitor under standard room temperature conditions (25°C room temperature conditions).

[0071] The controller calculates the current aging capacity of the capacitor based on the current energy storage capacity and the capacitor change coefficient. The specific calculation formula is as follows: ; in, This is the current aging capacitance of the capacitor. This represents the capacitance change coefficient corresponding to the current ambient temperature. It should be noted that when the ambient temperature is relative to standard room temperature, and the zero-crossing energy storage capacitor's capacitance decreases, the capacitance change coefficient becomes negative.

[0072] Step S204: Based on the current aging capacity of the capacitor and the standard recorded capacity of the zero-crossing energy storage capacitor, generate the estimated service life of the zero-crossing energy storage capacitor.

[0073] In practice, the controller calculates the estimated lifespan of the zero-crossing energy storage capacitor by analyzing the current usage time corresponding to the current aging capacity of the zero-crossing energy storage capacitor.

[0074] Specifically, the operation steps in step S204 are as follows: The controller pre-stores capacitor aging data for capacitors with zero energy storage, including multiple experimental aging times and corresponding experimental aging capacitor capacities.

[0075] Based on the current capacitor aging capacity, match the corresponding target experimental aging capacitor capacity from the capacitor aging data; An aging comparison coefficient is generated based on the target experimental aging time corresponding to the target experimental aging capacitor capacity and the current usage time of the zero-crossing energy storage capacitor. Based on the preset aging capacitor capacity threshold and aging comparison coefficient, the estimated service life is calculated and generated.

[0076] In practice, the controller matches the current capacitor aging capacity with the corresponding experimental aging time from the capacitor aging data. The matched experimental aging time is referred to as the target experimental aging time.

[0077] The controller then divides the target experimental aging time by the current usage time of the zero-crossing energy storage capacitor, and uses the quotient of the two as the aging comparison coefficient.

[0078] Then, the controller matches the capacitor aging threshold with the corresponding experimental aging time from the capacitor aging data. This matched experimental aging time can be called the threshold experimental aging time. Next, the threshold experimental aging time is multiplied by the aging comparison coefficient, and the product is used as the estimated usage time. The next step is to subtract the current usage time of the zero-crossing energy storage capacitor from the estimated usage time to calculate the remaining estimated lifespan of the zero-crossing energy storage capacitor.

[0079] In a transformer short-circuit fault current limiting device, the voltage and capacitance across the zero-crossing energy storage capacitor are related by the following formula: ; in, The voltage across the zero-crossing energy storage capacitor is the value of the voltage across the capacitor. To estimate the peak value of the short-circuit fault current on the main branch of the transformer short-circuit fault current limiting device, To modulate the inductive reactance of the inductor, This is the capacitance value of the zero-crossing energy storage capacitor.

[0080] Meanwhile, to address the impact of aging and temperature on the capacity of zero-crossing energy storage capacitors, the initial energy storage voltage across the zero-crossing energy storage capacitor is usually greater than the voltage value calculated by the above formula.

[0081] Optionally, in this application, there may also be such Figure 4 The specific operation process shown is as follows: Step S301: If the current energy storage capacity is less than the preset continuous use threshold of the capacitor, then calculate and generate the estimated regulation voltage based on the current energy storage capacity, the standard recorded capacity and the initial energy storage voltage.

[0082] In practice, the controller's memory stores a capacitor usage threshold in advance. This threshold is used to determine whether the zero-crossing energy storage capacitor can still maintain its initial energy storage voltage, thus meeting the need to create an artificial zero-crossing point in a vacuum fast switch.

[0083] The controller compares the current energy storage capacity with the capacitor's continuous usage threshold, and the comparison result can be one of the following two cases: Scenario 1: If the current energy storage capacity is less than the continuous use threshold of the capacitor, it means that the controller needs to adjust the initial energy storage voltage across the zero-crossing energy storage terminals to meet the requirement of creating an artificial zero-crossing point on the vacuum fast switch. Furthermore, the controller calculates and generates an estimated adjustment voltage based on the standard recorded capacity and the initial energy storage voltage, so as to adjust the initial energy storage voltage of the zero-crossing energy storage capacitor after the current moment using the estimated adjustment voltage. Scenario 2: If the current energy storage capacity is greater than or equal to the capacitor's continuous usage threshold, then there is no need to adjust the initial energy storage voltage across the zero-crossing energy storage capacitor.

[0084] Step S302: Compare the estimated regulation voltage with the preset voltage regulation threshold of the zero-crossing energy storage capacitor.

[0085] In implementation, the controller also pre-stores a voltage regulation threshold. This threshold is used to determine whether the zero-crossing energy storage capacitor can still meet the requirement of creating an artificial zero-crossing point on the vacuum fast switch by adjusting its own voltage alone. Specifically, the estimated regulation voltage is compared with the voltage regulation threshold. The comparison results are as follows: (1) The results are explained in steps S303 and S304, respectively.

[0086] Step S303: If the estimated regulation voltage is less than or equal to the voltage regulation threshold, then update the initial energy storage voltage of the zero-crossing energy storage capacitor according to the estimated regulation voltage.

[0087] In practice, after comparing the estimated regulation voltage with the voltage regulation threshold, if the estimated regulation voltage is less than or equal to the voltage regulation threshold, the controller can still meet the requirement of creating an artificial zero crossing point on the vacuum fast switch by simply adjusting the voltage across the zero-crossing energy storage capacitor. Therefore, the controller updates the initial energy storage voltage to the estimated regulation voltage.

[0088] Step S304: If the estimated adjustment voltage is greater than the voltage adjustment threshold, then based on the redundant capacitance value of the redundant spare capacitor connected in parallel with the zero-crossing energy storage capacitor, a common adjustment voltage value for the zero-crossing energy storage capacitor and the redundant spare capacitor is generated, and the initial energy storage voltage of the zero-crossing energy storage capacitor is updated based on the adjustment voltage value.

[0089] In implementation, after comparing the estimated regulation voltage with the voltage regulation threshold, if the estimated regulation voltage is greater than the voltage regulation threshold, simply adjusting the voltage across the zero-crossing energy storage capacitor is insufficient to create an artificial zero-crossing point on the vacuum fast switch. Therefore, the controller needs to control all three switching transistors to be on, allowing the zero-crossing energy storage capacitor and the redundant backup capacitor to work together. Furthermore, using the capacitance value of the redundant capacitor and the current energy storage capacity, the common adjustable voltage value for the zero-crossing energy storage capacitor and the redundant backup capacitor is calculated, and the initial energy storage voltage is updated to the adjustable voltage value.

[0090] In this application, the voltage across the zero-crossing energy storage capacitor is adjusted by analyzing whether redundant backup capacitors are needed, in order to meet the requirement of creating an artificial zero-crossing point in a vacuum fast switch.

[0091] Specifically, in step S301, there are also the following: Figure 5 The specific operation process shown is as follows: Step S3011: Obtain the historical ambient temperature information of the zero-crossing energy storage capacitor and filter out the historical ambient temperature peaks.

[0092] In implementation, the controller acquires historical ambient temperature information of the environment in which the zero-crossing energy storage capacitor is located. This historical ambient temperature information is typically recorded as the historical ambient temperature values ​​over a period of one year. Furthermore, the controller filters the historical ambient temperature information for the highest historical ambient temperature value, which is referred to as the historical ambient temperature peak value.

[0093] Step S3012: Based on historical ambient temperature peaks, capacitor temperature change capacitance data, and current capacitor aging capacitance value, generate an estimated baseline storage capacity value.

[0094] In implementation, the controller uses historical peak ambient temperature to match the corresponding capacitance change coefficient in the capacitor temperature-dependent capacitance data. This matched capacitance change coefficient can be called the peak capacitance change coefficient. Then, the peak capacitance change coefficient is multiplied by the current capacitor aging capacity to calculate the estimated baseline storage capacity.

[0095] Step S3013: Generate a zero-crossing current reference value based on the standard recorded capacity, initial energy storage voltage, and inductive reactance value of the modulation inductor.

[0096] In implementation, the controller follows the formula provided above. The reference value of the zero-crossing current is calculated using the standard recorded capacitance of the zero-crossing energy storage capacitor, the initial energy storage voltage, and the inductive reactance of the modulation inductor.

[0097] Step S3014: Calculate and generate the estimated regulation voltage based on the zero-crossing current reference value and the estimated bottom-line energy storage capacitor value.

[0098] In implementation, the controller then uses the formula provided above. The estimated regulation voltage is calculated using the zero-crossing current reference value, the inductive reactance of the modulation inductor, and the estimated bottom-line storage capacitance value.

[0099] Specifically, in step S304, there are also... Figure 6 The processing steps shown are as follows: Step S3041: Calculate the combined estimated storage capacity value by combining the redundant capacitor value and the estimated baseline storage capacity value.

[0100] In practice, when it is necessary to activate the redundant backup capacitor, the controller first adds the value of the redundant capacitor to the estimated baseline storage capacity value to calculate the joint estimated storage capacity value.

[0101] Since redundant spare capacitors are usually added after the zero-crossing energy storage capacitor has been in use for a period of time, in order to extend the service life of the zero-crossing energy storage capacitor, and are relatively small capacitors, the aging loss and temperature effect of the redundant spare capacitors are not considered in this application.

[0102] Step S3042: Based on the zero-crossing current and the jointly estimated storage capacitor value, calculate and generate the common adjustable voltage value of the zero-crossing reserve capacitor and the standby capacitor.

[0103] In practice, the controller uses the formula provided above to estimate the storage capacitor value, the zero-crossing current reference value, and the inductive reactance value of the modulation inductor, and calculates the common adjustable voltage value of the zero-crossing storage capacitor and the backup capacitor.

[0104] This application also discloses a controller, which includes: The instruction control module is used to control the switching transistor 1 to turn off and the energy-consuming bidirectional thyristor 1 to turn on after receiving the capacitor detection instruction. The information monitoring module is used to acquire the capacitor energy storage voltage across the zero-crossing energy storage capacitor and the energy consumption current value flowing through the energy consumption detection branch in real time. The instruction control module controls the energy-consuming bidirectional thyristor to turn off when the energy storage voltage across the zero-crossing energy storage capacitor is equal to the preset voltage detection threshold, and records the discharge detection duration of the zero-crossing energy storage capacitor. The data processing and analysis module is used to generate the current energy storage capacity of the zero-crossing energy storage capacitor based on the preset initial energy storage voltage, voltage detection threshold, real-time energy consumption current value, and discharge detection duration of the zero-crossing energy storage capacitor. The capacitor life estimation module is used to generate the estimated lifespan of the zero-crossing energy storage capacitor based on the pre-input standard recorded capacity of the zero-crossing energy storage capacitor and the current energy storage capacity.

[0105] Optional, controller, specifically used for: The data processing and analysis module is used to generate the capacitor voltage difference based on the initial energy storage voltage of the zero-crossing energy storage capacitor and the voltage detection threshold. The data processing and analysis module is used to calculate the current stored charge of the zero-crossing energy storage capacitor based on multiple energy consumption current values ​​and discharge detection duration. The data processing and analysis module is used to calculate the current energy storage capacity of the zero-crossing energy storage capacitor based on the current stored charge and the voltage difference between the capacitors.

[0106] Optional, controller, specifically used for: The information monitoring module is used to obtain the current ambient temperature of the zero-crossing energy storage capacitor; The data processing and analysis module is used to match the corresponding current capacitance change coefficient based on the capacitance temperature change data and the current ambient temperature. The data processing and analysis module is used to calculate and generate the current capacitor aging capacity based on the capacitance change coefficient and the current energy storage capacity. The capacitor life estimation module is used to generate the estimated lifespan of the zero-crossing energy storage capacitor based on the current aging capacity of the capacitor and the standard recorded capacity of the zero-crossing energy storage capacitor.

[0107] Optional, controller, specifically used for: The data processing and analysis module is used to match the corresponding target experimental aging capacitor capacity in the capacitor aging data based on the current capacitor aging capacity. The data processing and analysis module is used to generate an aging comparison coefficient based on the target experimental aging time corresponding to the target experimental aging capacitor capacity and the current usage time of the zero-crossing energy storage capacitor. The capacitor life estimation module is used to calculate and generate an estimated lifespan based on a preset aging capacitor capacity threshold and aging comparison coefficient.

[0108] Optionally, the controller can also be used for: The comparative analysis module calculates and generates an estimated adjustment voltage based on the current energy storage capacity, the standard recorded capacity, and the initial energy storage voltage if the current energy storage capacity is less than the preset continuous use threshold of the capacitor. The comparison and analysis module is used to compare the estimated regulation voltage with the preset voltage regulation threshold of the zero-crossing energy storage capacitor; The data update processing module updates the initial energy storage voltage of the zero-crossing energy storage capacitor based on the estimated adjustment voltage if the estimated adjustment voltage is less than or equal to the voltage adjustment threshold. If the estimated adjustment voltage is greater than the voltage adjustment threshold, the data update processing module generates a common adjustment voltage value for the zero-crossing reserve capacitor and the redundant reserve capacitor based on the redundant capacitor value connected in parallel with the zero-crossing energy storage capacitor, and updates the initial energy storage voltage of the zero-crossing energy storage capacitor based on the adjustment voltage value.

[0109] Optional, controller, specifically used for: The information monitoring module is used to acquire historical ambient temperature information of the zero-crossing energy storage capacitor and filter out the historical ambient temperature peaks. The data processing and analysis module is used to generate an estimated baseline storage capacity value based on historical peak ambient temperature, capacitor temperature change capacity data, and current capacitor aging capacitance value. The data processing and analysis module is used to generate a zero-crossing current reference value based on the standard recorded capacity, initial energy storage voltage, and inductive reactance of the modulation inductor. The data processing and analysis module is used to calculate and generate the estimated regulation voltage based on the zero-crossing current reference value and the estimated bottom-line energy storage capacitor value.

[0110] Optional, controller, specifically used for: The data processing and analysis module is used to calculate and generate a joint estimated storage capacity value from the redundant capacitor value and the estimated baseline storage capacity value. The data processing and analysis module is used to calculate and generate the common adjustable voltage value of the zero-crossing reserve capacitor and the standby capacitor based on the zero-crossing current and the jointly estimated storage capacitor value.

[0111] The controller can vary considerably depending on its configuration or performance, and may include one or more central processing units (e.g., one or more processors) and memory, and one or more storage media (e.g., one or more mass storage devices) for storing applications or data. The memory and storage media can be temporary or persistent storage. The program stored on the storage media may include one or more modules (not shown in the figure), each module including a series of instructions to operate on the controller.

[0112] The controller may also include one or more power supplies, one or more wired or wireless network interfaces, one or more input / output interfaces, one or more keyboards, and / or one or more operating systems.

[0113] The controller may include a memory and one or more programs, wherein one or more programs are stored in the memory and configured to be executed by one or more processors. One or more programs include the processing of the controller in the capacitor maintenance management method in the above-mentioned transformer short-circuit fault current limiting device.

[0114] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory.

[0115] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

[0116] While the present invention has been disclosed above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present invention, and all such changes and modifications will fall within the scope of protection of the present invention.

Claims

1. A transformer short-circuit fault current limiting device, characterized in that: It includes main branch circuits, current limiting branch circuits, energy absorbing branch circuits, modulation inductors, artificial zero-crossing branch circuits, and energy consumption detection branch circuits; Vacuum fast switches are connected in series between the busbar and the primary side port of the transformer on the main branch line; A current-limiting reactor connected in parallel to the vacuum fast switch is provided on the current-limiting branch; The energy-absorbing branch is connected in series with the modulation inductor and then in parallel with the current-limiting branch. A nonlinear resistor group is provided on the energy-absorbing branch, which is composed of multiple zinc oxide resistors connected in series and parallel. The artificial zero-crossing branch is connected in parallel to the energy-absorbing branch, and the artificial zero-crossing branch includes an energy storage capacitor bank module and a vacuum trigger switch connected in series. The energy consumption detection branch is connected in parallel to the energy storage capacitor bank module. The energy consumption detection branch includes a switch selection module, an energy consumption resistor, and an energy consumption inductor connected in series.

2. The apparatus according to claim 1, characterized in that: The energy storage capacitor bank module includes a zero-crossing energy storage capacitor, a first switching transistor, a zero-crossing spare capacitor, and a second switching transistor. The zero-crossing energy storage capacitor is connected in series with the switching transistor to form a first zero-crossing energy storage submodule; The zero-crossing backup capacitor is connected in series with the second switch to form a second zero-crossing energy storage submodule, and the first zero-crossing submodule and the second zero-crossing submodule are connected in parallel. The switch selection module includes a first energy-consuming bidirectional thyristor and a second energy-consuming bidirectional thyristor. The input terminal of the first energy-consuming bidirectional thyristor is electrically connected to the input terminal of the first switch, and the output terminal of the first energy-consuming bidirectional thyristor is electrically connected to the end of the energy-consuming resistor furthest from the energy-consuming resistor. The input terminal of the second energy-consuming bidirectional thyristor is electrically connected to the input terminal of the second switching transistor, and the output terminal of the second energy-consuming bidirectional thyristor is electrically connected to the output terminal of the first energy-consuming bidirectional thyristor.

3. The apparatus according to claim 2, characterized in that: The transformer short-circuit fault current limiting device also includes a controller, multiple current transformers, and multiple voltage transformers. The current transformers are respectively installed on the main branch, current limiting branch, energy absorption branch, artificial zero crossing branch and energy consumption detection branch, and multiple current transformers are respectively connected in parallel to the zero crossing energy storage capacitor and the zero crossing backup capacitor. The controller has multiple input terminals that are electrically connected to the output terminals of multiple current transformers and multiple voltage transformers, respectively; the controller has multiple control terminals that are electrically connected to the control terminals of the vacuum fast switch, the vacuum trigger switch, the first switch tube, the second switch tube, the first energy-consuming bidirectional thyristor, and the second energy-consuming bidirectional thyristor, respectively.

4. A capacitor maintenance and management method in a transformer short-circuit fault current limiting device, using the transformer short-circuit fault current limiting device as described in any one of claims 2 or 3, characterized in that, The method includes: Upon receiving the capacitance detection command, the control switch 1 is turned off and the energy-consuming bidirectional thyristor 1 is turned on; The energy storage voltage across the zero-crossing energy storage capacitor and the energy consumption current flowing through the energy consumption detection branch are acquired in real time. When the energy storage voltage across the zero-crossing energy storage capacitor is equal to the preset voltage detection threshold, the energy-consuming bidirectional thyristor is turned off, and the discharge detection duration of the zero-crossing energy storage capacitor is recorded. The current energy storage capacity of the zero-crossing energy storage capacitor is generated based on the preset initial energy storage voltage of the zero-crossing energy storage capacitor, the voltage detection threshold, the real-time energy consumption current value, and the discharge detection duration. Based on the pre-input standard recorded capacity of the zero-crossing energy storage capacitor and the current energy storage capacity, the estimated service life of the zero-crossing energy storage capacitor is generated.

5. The method according to claim 4, characterized in that, The step of generating the current energy storage capacity of the zero-crossing energy storage capacitor based on the preset initial energy storage voltage of the zero-crossing energy storage capacitor, the voltage detection threshold, and the real-time acquired energy consumption current value includes: A capacitor voltage difference is generated based on the initial energy storage voltage of the zero-crossing energy storage capacitor and the voltage detection threshold. The current stored charge of the zero-crossing energy storage capacitor is calculated based on the multiple energy consumption current values ​​and the discharge detection duration. The current energy storage capacity of the zero-crossing energy storage capacitor is calculated based on the current stored charge and the voltage difference of the capacitor.

6. The method according to claim 2, characterized in that, The controller also contains capacitor temperature-varying capacity data, which includes a capacitance change coefficient and a temperature value that are mapped to each other. The step of generating the estimated lifespan of the zero-crossing energy storage capacitor based on the pre-input standard recorded capacity of the zero-crossing energy storage capacitor and the current energy storage capacity includes: Obtain the current ambient temperature of the zero-crossing energy storage capacitor; Based on the capacitor temperature change capacitance data and the current ambient temperature, match the corresponding current capacitance change coefficient; The current capacitor aging capacity is calculated based on the capacitance change coefficient and the current energy storage capacity. The estimated lifespan of the zero-crossing energy storage capacitor is generated based on the current aging capacity of the capacitor and the standard recorded capacity of the zero-crossing energy storage capacitor.

7. The method according to claim 6, characterized in that, The controller has pre-stored the capacitor aging data of the zero-crossing energy storage capacitor, which includes multiple experimental aging times and corresponding multiple experimental aging capacitor capacities. The step of generating the estimated lifespan of the zero-crossing energy storage capacitor based on the current capacitor aging capacity and the pre-input standard recorded capacity includes: Based on the current capacitor aging capacity, the corresponding target experimental aging capacitor capacity is matched in the capacitor aging data. An aging comparison coefficient is generated based on the target experimental aging time corresponding to the target experimental aging capacitor capacity and the current usage time of the zero-crossing energy storage capacitor. The estimated service life is calculated based on the preset aging capacitor capacity threshold and the aging comparison coefficient.

8. The method according to claim 7, characterized in that, The method further includes: If the current energy storage capacity is less than the preset continuous use threshold of the capacitor, then the estimated adjustment voltage is calculated and generated based on the current energy storage capacity, the standard recorded capacity, and the initial energy storage voltage. Compare the estimated adjustment voltage with the preset voltage adjustment threshold of the zero-crossing energy storage capacitor; If the estimated adjustment voltage is less than or equal to the voltage adjustment threshold, then the initial energy storage voltage of the zero-crossing energy storage capacitor is updated according to the estimated adjustment voltage. If the estimated adjustment voltage is greater than the voltage adjustment threshold, then based on the redundant capacitance value of the redundant spare capacitor connected in parallel with the zero-crossing energy storage capacitor, a common adjustment voltage value for the zero-crossing energy storage capacitor and the redundant spare capacitor is generated, and the initial energy storage voltage of the zero-crossing energy storage capacitor is updated based on the adjustment voltage value.

9. The method according to claim 8, characterized in that, The step of calculating and generating the estimated regulation voltage based on the current storage capacity, the standard recorded capacity, and the initial energy storage voltage includes: Obtain the historical ambient temperature information of the zero-crossing energy storage capacitor and filter out the historical ambient temperature peaks; Based on the historical peak ambient temperature, the capacitor temperature change capacitance data, and the current capacitor aging capacitance value, an estimated baseline storage capacity value is generated. A zero-crossing current reference value is generated based on the standard recorded capacity, the initial energy storage voltage, and the inductive reactance value of the modulation inductor. Based on the zero-crossing current reference value and the estimated baseline energy storage capacitor value, the estimated regulation voltage is calculated and generated.

10. The method according to claim 9, characterized in that, The step of generating the common adjustable voltage value of the zero-crossing storage capacitor and the redundant backup capacitor based on the redundant capacitor value connected in parallel with the zero-crossing energy storage capacitor includes: The redundant capacitor value and the estimated baseline storage capacity value are used to calculate a joint estimated storage capacity value. Based on the zero-crossing current and the jointly estimated storage capacitor value, the common adjustable voltage value of the zero-crossing reserve capacitor and the standby capacitor is calculated and generated.

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