Circuit breaker control device

Abstract

The application relates to a circuit breaker control device. The circuit breaker control device comprises a voltage sampling module, which collects voltage signals of a power supply side and a load side of a circuit breaker; a state identification module, which analyzes the voltage signals to determine a system state of a power supply system; a strategy selection module, which determines a closing strategy corresponding to the system state according to the system state; and a closing execution module, which controls the circuit breaker to perform a closing operation corresponding to the closing strategy according to the selected closing strategy, so that adaptive switching of a circuit breaker closing strategy can be realized.

Description

Technical Field

[0001] This application relates to the field of power system automation and control technology, and in particular to a circuit breaker control device. Background Technology

[0002] In power systems, circuit breaker switching operations involve various operating conditions: differential frequency grid connection, loop grid connection, no-voltage closing, phase-selective closing, and phase-selective opening. Currently, these operating conditions are completed independently by different types of devices, such as synchronization devices, measurement and control devices, and phase-selective opening and closing devices.

[0003] However, the current method has the problem of not being able to adaptively switch the circuit breaker closing strategy. That is, it is currently necessary to manually switch different types of devices to switch the circuit breaker closing strategy, and it is not possible to achieve adaptive switching of the circuit breaker closing strategy. Summary of the Invention

[0004] Therefore, it is necessary to provide a circuit breaker control device that can realize automatic switching of circuit breaker closing strategies to address the above-mentioned technical problems.

[0005] In a first aspect, this application provides a circuit breaker control device, the device comprising:

[0006] The voltage sampling module is used to collect voltage signals from both sides of the circuit breaker; the two sides include the power supply side and the load side.

[0007] The status identification module, connected to the voltage sampling module, is used to analyze the collected voltage signals to determine the system status of the power supply system. The system status includes differential frequency status, same frequency status, no voltage on both sides status, and one side with voltage and the other side without voltage status.

[0008] The strategy selection module, connected to the status recognition module, is used to determine the closing strategy corresponding to the system status based on the system status.

[0009] The closing execution module, connected to the strategy selection module, is used to control the circuit breaker to perform the closing operation corresponding to the selected closing strategy.

[0010] In one embodiment, the state recognition module is used to perform zero-crossing detection on the voltage signals on both sides when the voltage signal on the power supply side corresponds to a power supply side voltage greater than a first preset voltage and the voltage signal on the load side corresponds to a load side voltage greater than a second preset voltage, so as to determine the power supply side frequency and the load side frequency; the first preset voltage is equal to a first preset proportion of the rated voltage on the power supply side and the second preset voltage is equal to a second preset proportion of the rated voltage on the load side.

[0011] The status identification module is used to determine the system status as a frequency difference state when the absolute value of the frequency difference between the power supply side frequency and the load side frequency is greater than a preset frequency difference value; and to determine the system status as a frequency match state when the absolute value of the frequency difference is less than or equal to the preset frequency difference value.

[0012] In one embodiment, the state recognition module is used to determine the system state as one side is under voltage and the other side is under voltage when one of the voltages on the power supply side and the load side is greater than the corresponding preset voltage; and to determine the system state as both sides are under voltage when the voltage on the power supply side is less than or equal to the first preset voltage and the voltage on the load side is less than or equal to the second preset voltage.

[0013] In one embodiment, the strategy selection module is used to determine the closing strategy as a synchronous closing strategy when the system state is a differential frequency state; to determine the closing strategy as a loop closing strategy when the system state is a same frequency state; to determine the closing strategy as a no-pressure closing strategy when the system state is a state with no pressure on both sides; and to determine the closing strategy as a phase-selective closing strategy when the system state is a state with pressure on one side and no pressure on the other side.

[0014] In one embodiment, the phase-selective closing strategy includes transformer no-load closing, capacitor combination closing, reactor closing and no-load line closing, and the phase-selective closing strategy is determined based on the load characteristics of the load connected to the circuit breaker.

[0015] The closing execution module is used to calculate the residual magnetism of the iron core by integration based on the instantaneous voltage waveform when the phase selection closing strategy is transformer no-load closing, and to calculate the first closing angle based on the polarity and magnitude of the residual magnetism, and to control the circuit breaker to close based on the first closing angle.

[0016] The closing execution module is used to close the circuit breaker at the zero-crossing point of a fully discharged capacitor when the phase selection closing strategy is capacitor combination closing strategy. For a target capacitor that is not discharged or whose switching frequency is greater than the preset frequency, the module detects the residual voltage polarity and amplitude on the target capacitor. When a closing command is received, the module calculates the second closing angle based on the voltage polarity and amplitude, and controls the circuit breaker to close based on the second closing angle.

[0017] The closing execution module is used to control the circuit breaker to close at the zero-crossing point of the grid current or the peak point of the grid voltage when the phase selection closing strategy is reactor closing.

[0018] The closing execution module is used to control the circuit breaker to close within a preset sampling interval when the phase selection closing strategy is to close the unloaded line. The preset sampling interval includes the interval consisting of a first preset number of sampling points before the voltage zero crossing point, the voltage zero crossing point, and a second preset number of sampling points thereafter.

[0019] In one embodiment, the device further includes:

[0020] The time compensation module is used to compensate the closing time corresponding to the second closing angle according to the closing time compensation model to obtain the target closing execution time; the closing time compensation model is determined based on the correspondence between the actual action time of each closing operation of the circuit breaker and the closing operation conditions;

[0021] The closing execution module is used to control the circuit breaker to close at the target closing execution time.

[0022] In one embodiment, the device further includes:

[0023] The time compensation module is used to compensate the opening time corresponding to the opening command according to the opening time compensation model to obtain the target opening execution time; the opening time compensation model is determined based on the correspondence between the actual action time of each opening operation of the circuit breaker and the opening operation conditions;

[0024] The circuit breaker tripping module is used to control the circuit breaker to trip according to the target tripping execution time.

[0025] In one embodiment, the device further includes:

[0026] The current sampling module is used to acquire the current signal on the load side;

[0027] The load characteristic identification module, connected to the current sampling module and the voltage sampling module, is used to determine the load characteristics of the load connected to the circuit breaker based on the current signal and the voltage signal on the load side collected by the voltage sampling module.

[0028] In one embodiment, the load characteristic identification module is used to perform zero-crossing detection on the voltage signal and current signal on the load side collected by the voltage sampling module to obtain the voltage zero-crossing time and the current zero-crossing time, and determine the time difference between the current zero-crossing time and the voltage zero-crossing time, and determine the phase difference based on the time difference.

[0029] The load characteristic identification module is used to determine that the load characteristic of the load connected to the circuit breaker is inductive when the time difference is greater than a preset time difference or the phase difference is within the range of [0, 90] degrees; and to determine that the load characteristic of the load connected to the circuit breaker is capacitive when the time difference is less than a preset value or the phase difference is within the range of [-90, 0] degrees.

[0030] In one embodiment, the tripping execution module is used to collect the voltage waveform of the inductive load for the inductive load with inductive load characteristics after the tripping operation is completed, and to determine that a current-cutting overvoltage has been detected when an abnormal overvoltage occurs in the voltage waveform, record the current-cutting overvoltage and issue a first alarm message.

[0031] The circuit breaker execution module is used to accumulate the number of reignitions for capacitive loads with capacitive characteristics after the circuit breaker operation is completed, in the event of high-frequency oscillating current or voltage sudden change in the capacitive load, and to issue a second alarm message if the current number of reignitions exceeds the preset number.

[0032] The aforementioned circuit breaker control device collects voltage signals from the power supply side and load side of the circuit breaker, analyzes the voltage signals to determine the system state of the power supply system, determines the closing strategy corresponding to the system state based on the system state, and controls the circuit breaker to perform the closing operation corresponding to the selected closing strategy, thereby enabling adaptive switching of the circuit breaker closing strategy. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0034] Figure 1 This is a structural block diagram of a circuit breaker control device in one embodiment;

[0035] Figure 2 This is a structural block diagram of a circuit breaker control device in another embodiment;

[0036] Figure 3 This is a structural block diagram of an adaptive precision cutting intelligent control device in one embodiment. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0038] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0039] To facilitate the introduction of the embodiments of this application, the technical terms and core modules involved in this application will be introduced first:

[0040] Differential frequency grid connection: When the generator is connected to the grid, the frequencies on both sides are different, and a synchronizing device is required to capture the zero phase angle difference for closing.

[0041] Ring connection: When ring networks are connected in parallel, the frequencies on both sides are the same but there is a power angle difference. The circuit breaker must be closed within the allowable phase angle difference range.

[0042] No-voltage closing: When there is no voltage on both sides of the circuit breaker, the circuit breaker can be closed directly.

[0043] Selective phase closing: When one side is energized and the other side is de-energized, the circuit should be closed at the optimal phase angle according to the load characteristics (transformer, capacitor, reactor, line) to suppress inrush current and overvoltage.

[0044] Selective phase tripping: This method relies on the arc-extinguishing principle of the circuit breaker's current crossing zero point. It generally uses current crossing zero point tripping, but lacks status monitoring after tripping.

[0045] Voltage sampling module: Real-time acquisition of voltage signals on both sides of the circuit breaker (power supply side and load side).

[0046] Status recognition module: Analyzes the sampled voltage and automatically identifies the current system status.

[0047] Strategy selection module: Automatically selects the corresponding closing strategy based on the identification results.

[0048] Phase selection control module: Executes phase selection opening and closing algorithm, calculates the optimal closing angle and compensates for circuit breaker operating time.

[0049] Human-computer interaction module: Provides functions such as parameter setting, status display, event logging, and waveform viewing.

[0050] like Figure 1 As shown, a circuit breaker control device is provided, which includes a voltage sampling module, a status identification module, a strategy selection module, and a closing execution module, wherein:

[0051] The voltage sampling module is used to collect voltage signals from both sides of the circuit breaker; the two sides include the power supply side and the load side.

[0052] The status identification module, connected to the voltage sampling module, is used to analyze the two acquired voltage signals to determine the system status of the power supply system. The system status includes differential frequency status, same frequency status, no voltage on both sides, and one side with voltage and the other side without voltage.

[0053] The strategy selection module, connected to the status recognition module, is used to determine the closing strategy corresponding to the system status based on the system status.

[0054] The closing execution module, connected to the strategy selection module, is used to control the circuit breaker to perform the closing operation corresponding to the selected closing strategy.

[0055] The voltage signal on the power supply side is denoted as Us, and the voltage signal on the load side is denoted as Ul. If the amplitude of Us, i.e., the voltage on the power supply side, is greater than a first preset voltage, and the amplitude of Ul, i.e., the voltage on the load side, is greater than a second preset voltage, then zero-crossing detection can be performed on the voltage signals on both sides to determine the power supply side frequency. and load-side frequency .like Then the system state is determined to be a difference frequency state, where, This is a preset frequency difference, for example, equal to 0.001Hz. If... If so, the system state is determined to be a state of same frequency.

[0056] If either the power supply voltage or the load voltage is greater than the corresponding preset voltage, the system state is determined to be a state where one side is under voltage and the other side is under voltage; if the power supply voltage is less than or equal to the first preset voltage and the load voltage is less than or equal to the second preset voltage, the system state is determined to be a state where both sides are under voltage.

[0057] For ease of explanation, a state where the voltage on one side is greater than the corresponding preset voltage is denoted as "voltage present," and a state where the voltage on one side is less than or equal to the corresponding preset voltage is denoted as "voltage absent." For example, a power supply side voltage greater than a first preset voltage is called "voltage present," and a load side voltage greater than a second preset voltage is also called "voltage present." Specifically, refer to Table 1 below, which shows the correspondence between power supply side voltage, load side voltage, frequency, and system states:

[0058] Table 1

[0059]

[0060] As shown in Table 2 below, Table 2 illustrates the correspondence between system status, closing strategy, and control logic. Here, control logic refers to the control logic related to the closing operation.

[0061] Table 2

[0062]

[0063] Based on Table 2 above, the following strategies are implemented: synchronous closing under differential frequency conditions; loop closing under same frequency conditions; no-pressure closing under both pressure conditions; and phase-selective closing under pressure conditions on one side and no pressure under other side conditions.

[0064] In this embodiment, voltage signals from the power supply side and load side of the circuit breaker are collected and analyzed to determine the system state of the power supply system. Based on the system state, a closing strategy corresponding to that state is determined, and the circuit breaker is controlled to perform the closing operation corresponding to the selected closing strategy. By automatically identifying the system state through voltage signals from the power supply side and load side, manual judgment and switching are eliminated, avoiding the risk of misoperation. Furthermore, because the closing strategy corresponding to the system state can be determined, and the circuit breaker can be controlled to perform the closing operation corresponding to the selected closing strategy, adaptive switching of the circuit breaker closing strategy can be achieved.

[0065] In an exemplary embodiment, the state recognition module is used to perform zero-crossing detection on the voltage signals on both sides when the power supply voltage corresponding to the voltage signal on the power supply side is greater than a first preset voltage and the load voltage corresponding to the voltage signal on the load side is greater than a second preset voltage, so as to determine the power supply frequency and the load frequency; the first preset voltage is equal to a first preset ratio of the rated voltage on the power supply side and the second preset voltage is equal to a second preset ratio of the rated voltage on the load side.

[0066] The status identification module is used to determine the system status as a frequency difference state when the absolute value of the frequency difference between the power supply side frequency and the load side frequency is greater than a preset frequency difference value; and to determine the system status as a frequency match state when the absolute value of the frequency difference is less than or equal to the preset frequency difference value.

[0067] In this embodiment, a pre-judgment is performed by setting a voltage threshold on both sides. Zero-crossing detection is only initiated when there is effective voltage on both sides, thereby suppressing frequency mismeasurement caused by induced residual voltage and electromagnetic noise, and improving the accuracy of state recognition.

[0068] In an exemplary embodiment, the state recognition module is used to determine the system state as one side is under voltage and the other side is under voltage when one of the voltages on the power supply side and the load side is greater than the corresponding preset voltage; and to determine the system state as both sides are under voltage when the voltage on the power supply side is less than or equal to the first preset voltage and the voltage on the load side is less than or equal to the second preset voltage.

[0069] In this embodiment, by determining the system state, reliable criteria can be provided for the circuit breaker closing control logic, thereby improving the safety and reliability of power distribution operation. Furthermore, this embodiment identifies four types of system operating states—no voltage on both sides, voltage on one side, same frequency, and differential frequency—and matches corresponding closing strategies to achieve full operational scenario adaptation: Differential frequency state is configured with a synchronous closing strategy to adapt to generator grid-connected operation; same frequency state is configured with a loop-closing closing strategy to adapt to distribution network ring network parallel transfer operation; single-side voltage state is equipped with multi-load subdivision phase selection closing logic to adapt to no-load switching of various electrical equipment such as transformers, capacitors, reactors, and no-load lines; two-side no-voltage state is configured with a no-voltage closing strategy to meet the needs of cold switching and power restoration operations during maintenance; simultaneously, it is combined with adaptive phase selection tripping and tripping transient result evaluation closed-loop control, fully covering all typical application scenarios of power system grid connection, loop closing, equipment switching, and switching operations, achieving multi-condition universality of a single device, thereby reducing equipment costs.

[0070] In an exemplary embodiment, the strategy selection module is configured to determine the closing strategy as a synchronous closing strategy when the system state is a differential frequency state; determine the closing strategy as a loop closing strategy when the system state is a same frequency state; determine the closing strategy as a no-pressure closing strategy when the system state is a state with no pressure on both sides; and determine the closing strategy as a phase-selective closing strategy when the system state is a state with pressure on one side and no pressure on the other side.

[0071] In this embodiment, a one-to-one matching closing strategy is used for four system states: synchronous closing is employed to avoid asynchronous grid connection impacts in differential frequency state; loop closing is used to achieve smooth power transfer in synchronous frequency state; no-voltage closing is used to quickly restore power supply in the state with no voltage on both sides; and phase-selective closing is used to suppress closing overvoltage and inrush current in the state with voltage on one side and no voltage on the other. By mapping system states to closing strategies, the control logic becomes clearer and more reliable. This approach adapts to various operation and maintenance scenarios in the distribution network, improves the level of power supply automation, and balances power supply flexibility with grid operation safety. Furthermore, by integrating synchronous closing, loop closing, no-voltage closing, and phase-selective closing into the same circuit breaker control device, replacing multiple independent devices, investment costs and operation and maintenance complexity are reduced.

[0072] In an exemplary embodiment, the phase-selective closing strategy includes transformer no-load closing, capacitor combination closing, reactor closing, and no-load line closing. The phase-selective closing strategy is determined based on the load characteristics of the load connected to the circuit breaker.

[0073] The closing execution module is used to calculate the residual magnetism of the iron core by integration based on the instantaneous voltage waveform when the phase selection closing strategy is transformer no-load closing, and to calculate the first closing angle based on the polarity and magnitude of the residual magnetism, and to control the circuit breaker to close based on the first closing angle.

[0074] The closing execution module is used to close the circuit breaker at the zero-crossing point of a fully discharged capacitor when the phase selection closing strategy is capacitor combination closing strategy. For a target capacitor that is not discharged or whose switching frequency is greater than the preset frequency, the module detects the residual voltage polarity and amplitude on the target capacitor. When a closing command is received, the module calculates the second closing angle based on the voltage polarity and amplitude, and controls the circuit breaker to close based on the second closing angle.

[0075] The closing execution module is used to control the circuit breaker to close at the zero-crossing point of the grid current or the peak point of the grid voltage when the phase selection closing strategy is reactor closing.

[0076] The closing execution module is used to control the circuit breaker to close within a preset sampling interval when the phase selection closing strategy is to close the unloaded line. The preset sampling interval includes the interval consisting of a first preset number of sampling points before the voltage zero crossing point, the voltage zero crossing point, and a second preset number of sampling points thereafter.

[0077] Among them, the transformer is switched on under no-load conditions:

[0078] When the circuit breaker is opened: record the voltage waveform at the instant of opening, and calculate the residual magnetism of the iron core by integration;

[0079] When closing the circuit: Calculate the optimal closing angle, also known as the first closing angle, based on the magnitude and polarity of the residual magnetism, so that the initial magnetic flux is in the same direction as the residual magnetism and their magnitudes are close.

[0080] Capacitor combination switch:

[0081] For a fully discharged capacitor: the circuit breaker is closed at the voltage zero-crossing point;

[0082] For capacitors that are not discharged or frequently switched: detect the polarity and amplitude of the residual voltage on the capacitor. When a closing command is received, calculate an optimal closing angle, also known as the second closing angle, so that the system voltage at the time of connection is equal to the amplitude and polarity of the residual voltage on the capacitor, thereby achieving "zero differential voltage" closing.

[0083] Reactor closing: closing the circuit at the point where the current crosses zero (the point where the voltage peaks).

[0084] No-load line closing: Closing the circuit near the voltage zero-crossing point to suppress operational overvoltage. Here, "near the voltage zero-crossing point" refers to a preset sampling interval, which includes the interval consisting of a first preset number of sampling points before the voltage zero-crossing point, the voltage zero-crossing point itself, and a second preset number of sampling points thereafter.

[0085] In this embodiment, differentiated phase selection and closing strategies are set for four typical loads, namely four equipment types: transformers, capacitor banks, reactors, and unloaded lines. Compared with single-mode phase selection and closing, this strategy is specifically adapted to the transient characteristics of different equipment, resulting in better suppression of closing transient impacts, reducing disturbances to the power grid and damage to primary equipment. At the same time, a single control strategy can be compatible with various power distribution equipment switching conditions, has strong versatility, and its modular control logic is easy to implement. This can effectively reduce the probability of protection malfunction and improve the operational stability and power supply reliability of the power distribution system.

[0086] In one exemplary embodiment, such as Figure 2 As shown, the circuit breaker control device also includes:

[0087] The time compensation module is used to compensate the closing time corresponding to the second closing angle according to the closing time compensation model to obtain the target closing execution time; the closing time compensation model is determined based on the correspondence between the actual action time of each closing operation of the circuit breaker and the closing operation conditions;

[0088] The closing execution module is used to control the circuit breaker to close at the target closing execution time.

[0089] The closing operation conditions may include ambient temperature, control voltage, and closing operation frequency. For example, closing operation condition 1 corresponds to actual action time 1, and closing operation condition 2 corresponds to actual action time 2. If the current closing operation condition is the same as closing operation condition 1, the closing time corresponding to the second closing angle can be compensated based on actual action time 1 to obtain the target closing execution time. For instance, if actual action time 1 is 60 milliseconds and the closing time corresponding to the second closing angle is 58 milliseconds, then the closing time corresponding to the second closing angle can be compensated by 2 milliseconds, thereby using 60 milliseconds as the target closing execution time.

[0090] Among them, the actual operating time of each closing operation of the circuit breaker can be recorded, and a relationship model can be established between the actual operating time and the ambient temperature, control voltage, and number of closing operations. Based on this relationship model, the timing of the closing command can be corrected in real time to ensure that the contacts are closed at the target phase.

[0091] In this embodiment, the target closing execution time is obtained by compensating the closing time corresponding to the second closing angle. The circuit breaker is then controlled to close at the target closing execution time, achieving dynamic correction of the closing command output time. This effectively offsets the drift deviation of the circuit breaker's mechanical action time caused by multiple factors, ensuring that the contact closing time accurately matches the preset optimal closing phase, and improving the phase control accuracy of phase-selective closing, synchronous closing, and loop closing. Furthermore, it eliminates the need for maintenance personnel to periodically conduct on-site measurements and manually modify delay parameters, reducing on-site debugging workload, ensuring good long-term operational consistency of the device, and lowering subsequent maintenance costs.

[0092] In one exemplary embodiment, such as Figure 2 As shown, the time compensation module is used to compensate the opening time corresponding to the opening command according to the opening time compensation model to obtain the target opening execution time; the opening time compensation model is determined based on the correspondence between the actual action time of each opening operation of the circuit breaker and the opening operation conditions.

[0093] The circuit breaker tripping module is used to control the circuit breaker to trip according to the target tripping execution time.

[0094] The conditions for tripping operations may include ambient temperature, control voltage, and tripping operation frequency. The method for compensating the tripping time corresponding to the tripping command to obtain the target tripping execution time is similar to the method in the above embodiment for compensating the closing time corresponding to the second closing angle to obtain the target closing execution time.

[0095] The device monitors the current waveform in real time, predicts the next natural current zero-crossing point, and accurately calculates the inherent tripping action time through a time compensation module, issuing the tripping command in advance to ensure that the circuit breaker contacts separate at the current zero-crossing point. This device can employ a unified current zero-crossing tripping strategy for both inductive and capacitive loads, conforming to the physical characteristics of the circuit breaker while simultaneously suppressing overvoltage in inductive loads and reducing the risk of reignition in capacitive loads. Furthermore, it combines load characteristic identification results for differentiated diagnosis, providing data support for condition-based maintenance of the circuit breaker.

[0096] In this embodiment, the target tripping execution time is obtained by compensating the tripping time corresponding to the tripping command. Based on the target tripping execution time, the circuit breaker is controlled to trip, which can automatically compensate for the tripping time drift deviation caused by temperature, control voltage, and mechanical aging, so as to achieve precise and controllable tripping time and improve the switch control accuracy and long-term operation stability.

[0097] In one exemplary embodiment, such as Figure 2 As shown, the circuit breaker control device also includes:

[0098] The current sampling module is used to acquire the current signal on the load side;

[0099] The load characteristic identification module, connected to the current sampling module and the voltage sampling module, is used to determine the load characteristics of the load connected to the circuit breaker based on the current signal and the voltage signal on the load side collected by the voltage sampling module.

[0100] The voltage and instantaneous current values ​​on the load side of the circuit breaker are synchronously acquired using a voltage sampling module and a current sampling module (the device needs to be equipped with an additional current input channel) at a high sampling rate (e.g., 24 points per cycle). The instantaneous current value is also known as the current signal.

[0101] Zero-crossing detection is performed on the sampled voltage and current signals to obtain the voltage zero-crossing time. With the moment of zero current crossing Calculate the time difference between the two. and convert it into phase difference ,in The power frequency period (e.g., 20ms).

[0102] When the time difference is less than the preset value (i.e., the current zero-crossing point lags behind the voltage zero-crossing point, the phase difference is less than the preset value), exist to Within the specified range, the load characteristic of the load connected to the circuit breaker is determined to be capacitive, meaning the load connected to the circuit breaker is a capacitive load. The preset value is 0, meaning that within... In this case, the load characteristic of the load connected to the circuit breaker is determined to be capacitive.

[0103] like (That is, the current zero-crossing point leads the voltage zero-crossing point, in) to If the load is within the specified range, then the load is determined to be a capacitive load.

[0104] In this embodiment, the load characteristics of the load connected to the circuit breaker are determined by the current signal and the voltage signal on the load side collected by the voltage sampling module, so as to automatically identify the load type and automatically determine whether the current load is a transformer, capacitor bank, reactor, unloaded line, etc., and thus automatically call the differentiated phase selection and closing strategy according to the identified load characteristics.

[0105] In an exemplary embodiment, the load characteristic identification module is used to perform zero-crossing detection on the voltage signal and current signal on the load side collected by the voltage sampling module to obtain the voltage zero-crossing time and the current zero-crossing time, and determine the time difference between the current zero-crossing time and the voltage zero-crossing time, and determine the phase difference based on the time difference.

[0106] The load characteristic identification module is used to determine that the load characteristic of the load connected to the circuit breaker is inductive when the time difference is greater than a preset time difference or the phase difference is within the range of [0, 90] degrees; and to determine that the load characteristic of the load connected to the circuit breaker is capacitive when the time difference is less than a preset value or the phase difference is within the range of [-90, 0] degrees.

[0107] In this embodiment, by comparing the time offset of the zero-crossing point of voltage and current, the phase lead-lag relationship can be quickly determined. Current lagging behind voltage indicates an inductive load, and current leading voltage indicates a capacitive load. The computation is small, the identification response speed is fast, and the accuracy of load characteristic determination is high.

[0108] In an exemplary embodiment, the tripping execution module is used to, after the tripping operation is completed, collect the voltage waveform of the inductive load with inductive load characteristics, and if an abnormal overvoltage occurs in the voltage waveform, determine that a current-cutting overvoltage has been detected, record the current-cutting overvoltage, and issue a first alarm message.

[0109] The circuit breaker execution module is used to accumulate the number of reignitions for capacitive loads with capacitive characteristics after the circuit breaker operation is completed, in the event of high-frequency oscillating current or voltage sudden change in the capacitive load, and to issue a second alarm message if the current number of reignitions exceeds the preset number.

[0110] Upon receiving a tripping command, the device executes a uniform tripping strategy based on the current zero-crossing point. Regardless of whether the load is inductive or capacitive, the circuit breaker is controlled to trip at the current zero-crossing point. However, its physical objectives and protection mechanisms are quite different.

[0111] After determining the load characteristics, a unified current zero-crossing tripping strategy can be implemented: the device monitors the current waveform in real time, predicts the next natural current zero-crossing point, and accurately calculates the inherent tripping action time through the time compensation module, and issues a tripping command to ensure that the circuit breaker contacts separate at the current zero-crossing point.

[0112] After the tripping operation is completed, the device evaluates the tripping result based on the load characteristics: For inductive loads: focus on monitoring for abnormal overvoltages, determine if it is a current-cutting overvoltage event, record and issue an early warning. For capacitive loads: focus on detecting for high-frequency oscillating currents or voltage surges, determine if it is a reignition event, record the number of reignitions, and issue a circuit breaker maintenance alarm when the threshold is exceeded.

[0113] In this embodiment, for inductive loads, overvoltage is monitored and event recording and early warning are implemented. For capacitive loads, arc reignition is monitored, the number of reignitions is counted, and maintenance alarms are pushed after exceeding the limit. On the one hand, the transient suppression effect of the phase-selective tripping strategy can be verified, forming a closed-loop optimization of tripping control. On the other hand, the arc extinguishing and contact deterioration trends of the circuit breaker can be monitored in real time, and equipment insulation damage and switch failures caused by overvoltage and arc reignition can be avoided in a timely manner, realizing predictive operation and maintenance of circuit breaker status and improving the operational safety of the power distribution system.

[0114] It should be noted that the device in this embodiment can also support digital substations: it has an IEC 61850 communication interface and can be connected to an intelligent substation automation system. The device in this application automatically identifies the system status and adaptively selects the optimal strategy through voltage sampling on both sides, achieving full-scenario coverage, simplifying the system architecture, and improving operational reliability and intelligence.

[0115] In one exemplary embodiment, such as Figure 3As shown, DL1 is equipped with an integrated adaptive precision switching intelligent control device, where S1 represents the first power supply, S2 represents the second power supply, T1 represents the first transformer, and T2 represents the second transformer. This device can realize the switching operation of the first circuit breaker DL1 under various operating modes.

[0116] If DL1 is open, the second circuit breaker DL2 is open, the third circuit breaker DL3 is open, and the fourth circuit breaker DL4 is open, then DL1 is closed. At this time, the energized side is de-energized, and the device enters the phase selection and closing module.

[0117] If DL1 is open, DL2 is closed, DL3 is open, and DL4 is open at this time, and DL1 is closed, the power supply on both sides is different, and the device enters the synchronous closing module.

[0118] If DL1 is open, DL2 is closed, DL3 is closed, and DL4 is closed at this time, and DL1 switch is closed, then both sides are powered by the same power source, and the device enters the loop closing module.

[0119] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0120] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0121] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. A circuit breaker control device, characterized in that, The device includes: A voltage sampling module is used to collect voltage signals from both sides of the circuit breaker; the two sides include the power supply side and the load side. A status identification module, connected to the voltage sampling module, is used to analyze the collected voltage signal to determine the system status of the power supply system; the system status includes differential frequency status, same frequency status, no voltage on both sides status, and one side with voltage and the other side without voltage status; The strategy selection module is connected to the status recognition module and is used to determine the closing strategy corresponding to the system status based on the system status. The closing execution module is connected to the strategy selection module and is used to control the circuit breaker to perform a closing operation corresponding to the selected closing strategy.

2. The apparatus according to claim 1, characterized in that, The state recognition module is used to perform zero-crossing detection on the voltage signals on both sides when the voltage signal on the power supply side corresponds to a power supply side voltage greater than a first preset voltage and the voltage signal on the load side corresponds to a load side voltage greater than a second preset voltage, in order to determine the power supply side frequency and the load side frequency; the first preset voltage is equal to a first preset proportion of the rated voltage on the power supply side and the second preset voltage is equal to a second preset proportion of the rated voltage on the load side. The state recognition module is used to determine the system state as the frequency difference state when the absolute value of the frequency difference between the power supply side frequency and the load side frequency is greater than a preset frequency difference. If the absolute value of the frequency difference is less than or equal to a preset frequency difference, the system state is determined to be the same frequency state.

3. The apparatus according to claim 2, characterized in that, The state recognition module is used to determine that the system state is a state where one side is under voltage and the other side is not under voltage when one of the voltages of the power supply side voltage and the load side voltage is greater than the corresponding preset voltage. When the voltage on the power supply side is less than or equal to the first preset voltage, and the voltage on the load side is less than or equal to the second preset voltage, the system state is determined to be a state with no voltage on both sides.

4. The apparatus according to any one of claims 1-3, characterized in that, The strategy selection module is used to determine the closing strategy as a synchronous closing strategy when the system state is the differential frequency state; to determine the closing strategy as a loop closing strategy when the system state is the same frequency state; to determine the closing strategy as a no-pressure closing strategy when the system state is a state with no pressure on both sides; and to determine the closing strategy as a phase-selective closing strategy when the system state is a state with pressure on one side and no pressure on the other side.

5. The apparatus according to claim 4, characterized in that, The phase-selective closing strategy includes transformer no-load closing, capacitor combination closing, reactor closing, and no-load line closing. The phase-selective closing strategy is determined based on the load characteristics of the load connected to the circuit breaker. The closing execution module is used to calculate the residual magnetism of the iron core by integration based on the instantaneous voltage waveform at the time of opening when the phase selection closing strategy is the transformer no-load closing, calculate the first closing angle based on the polarity and magnitude of the residual magnetism, and control the circuit breaker to close based on the first closing angle. The closing execution module is used to close the circuit breaker at the zero-crossing point for a fully discharged capacitor when the phase selection closing strategy is the capacitor combination circuit breaker, and to detect the residual voltage polarity and amplitude on the target capacitor when it is not discharged or the switching frequency is greater than the preset frequency. When a closing command is received, the module calculates the second closing angle based on the voltage polarity and amplitude, and controls the circuit breaker to close based on the second closing angle. The closing execution module is used to control the circuit breaker to close at the zero-crossing point of the grid current or the peak point of the grid voltage when the phase selection closing strategy is to close the reactor. The closing execution module is used to control the circuit breaker to close within a preset sampling interval when the phase selection closing strategy is to close the unloaded line; the preset sampling interval includes an interval consisting of a first preset number of sampling points before the voltage zero crossing point, the voltage zero crossing point, and a second preset number of sampling points thereafter.

6. The apparatus according to claim 5, characterized in that, The device further includes: The time compensation module is used to compensate the closing time corresponding to the second closing angle according to the closing time compensation model to obtain the target closing execution time; the closing time compensation model is determined based on the correspondence between the actual action time of each closing operation of the circuit breaker and the closing operation conditions. The closing execution module is used to control the circuit breaker to close at the target closing execution time.

7. The apparatus according to claim 6, characterized in that, The device further includes: The time compensation module is used to compensate the tripping time corresponding to the tripping command according to the tripping time compensation model to obtain the target tripping execution time; the tripping time compensation model is determined based on the correspondence between the actual action time of each tripping operation of the circuit breaker and the tripping operation conditions. The circuit breaker tripping execution module is used to control the circuit breaker to trip according to the target tripping execution time.

8. The apparatus according to claim 7, characterized in that, The device further includes: A current sampling module is used to collect the current signal on the load side; The load characteristic identification module is connected to the current sampling module and the voltage sampling module, and is used to determine the load characteristics of the load connected to the circuit breaker based on the current signal and the voltage signal on the load side collected by the voltage sampling module.

9. The apparatus according to claim 8, characterized in that, The load characteristic identification module is used to perform zero-crossing detection on the voltage signal and the current signal collected by the voltage sampling module on the load side, so as to obtain the voltage zero-crossing time and the current zero-crossing time, and determine the time difference between the current zero-crossing time and the voltage zero-crossing time, and determine the phase difference based on the time difference. The load characteristic identification module is used to determine that the load characteristic of the load connected to the circuit breaker is inductive when the time difference is greater than a preset time difference or the phase difference is within the range of [0, 90] degrees; and to determine that the load characteristic of the load connected to the circuit breaker is capacitive when the time difference is less than the preset value or the phase difference is within the range of [-90, 0] degrees.

10. The apparatus according to claim 9, characterized in that, The tripping execution module is used to collect the voltage waveform of the inductive load after the tripping operation is completed, and if an abnormal overvoltage occurs in the voltage waveform, determine that a current-cutting overvoltage has been detected, record the current-cutting overvoltage, and issue a first alarm message. The circuit breaker execution module is used to, after the circuit breaker operation is completed, accumulate the number of reignitions for capacitive loads with capacitive characteristics, in the event of high-frequency oscillating current or voltage sudden change in the capacitive load, and issue a second alarm message if the current number of reignitions exceeds a preset number.

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