Controllable current-limiting reactance protection device, control method, electronic equipment and medium

Abstract

The invention discloses a controllable current-limiting reactance protection device, a control method, electronic equipment and a medium. Relates to the field of transformers, and solves the problem of low speed of current-limiting protection of an energy storage type distribution transformer. The working state of a power grid circuit is monitored in real time, on and off of a switch tube are rapidly controlled, and the impedance of an access circuit is adjusted, so that the rise rate and the first peak value of fault current can be greatly reduced, an energy storage system and a distribution transformer are prevented from being damaged, and due to the fact that the switching speed of the switch tube is far higher than that of a mechanical switch, the reliability is high. Moreover, fault signals do not need to be analyzed and processed, connection and disconnection of a switching tube are directly controlled, the fault processing speed is also improved, effective current-limiting protection is provided for the energy storage type distribution transformer within a short time when the fault occurs, the current-limiting protection is not affected by operation delay, and the service life of the energy storage type distribution transformer is prolonged. The reliability and the stability of the energy storage type distribution transformer in a micro-grid environment are remarkably improved, and a powerful guarantee is provided for safe and stable operation of a power system.

Description

Technical Field

[0001] The present application relates to the field of transformers, and particularly to a controllable current-limiting reactance protection device, a control method, an electronic device and a medium. Background Art

[0002] In a microgrid with photovoltaic or wind power access, when a fault occurs, it is necessary to protect the energy storage distribution device. Otherwise, it may cause the battery energy storage system (BESS), the energy storage battery itself, or the voltage source converter of the energy storage to withstand excessive current and be damaged, resulting in the interruption of power transmission in the microgrid system.

[0003] Generally, the method of using a fault current limiter is adopted to protect the energy storage type distribution transformer. However, since the fault current limiter often uses a mechanical switch, when performing action switching, it is necessary to overcome factors such as mechanical inertia and friction. The controller needs to analyze and process the monitored electrical signals before performing protection control. Therefore, the methods of realizing current-limiting protection through a fault current limiter all have the problem of operation delay.

[0004] Therefore, how to improve the speed of current-limiting protection of the energy storage type distribution transformer is an urgent problem to be solved at present. Summary of the Invention

[0005] The purpose of the present application is to provide a controllable current-limiting reactance protection device, a control method, an electronic device and a medium, so as to solve the problem of slow speed of current-limiting protection of the energy storage type distribution transformer.

[0006] To solve the above technical problems, the present application provides a controllable current-limiting reactance protection device, including: a fault monitoring and control module, a rectification module and a reactance adjustment module; the fault monitoring and control module is connected to the line where the transformer is connected to the power grid to collect the working state of the power grid circuit; the reactance adjustment module includes a main coil and a secondary coil with an iron magnetic core, a first switching tube, a second switching tube, a first resistor and a second resistor;

[0007] The fault monitoring and control module is connected to the control ends of the first switching tube and the second switching tube; the input end of the rectification module is connected to the input line, the first output end of the rectification module is connected to the first end of the first switching tube and the first end of the first resistor, the second end of the first switching tube and the second end of the first resistor are connected to the first end of the main coil; the second output end of the rectification module is connected to the second end of the main coil; the first end of the secondary coil is connected to the first end of the second switching tube, the second end of the second switching tube is connected to the first end of the second resistor, and the second end of the secondary coil is connected to the second end of the second resistor;

[0008] The fault monitoring and control module controls the conduction and cutoff of the first switch tube and the second switch tube according to the working state of the power grid circuit, and adjusts the magnitude of the access impedance.

[0009] As an alternative solution, in the above controllable current-limiting reactance protection device, the fault monitoring and control module includes: a controller, a current transformer, and a voltage transformer;

[0010] The current transformer and the voltage transformer are connected to the power grid. The current transformer is used to detect the current value of the power grid; the voltage transformer is used to monitor the voltage value of the power grid;

[0011] The current transformer and the voltage transformer are connected to the controller.

[0012] As an alternative solution, in the above controllable current-limiting reactance protection device, the rectifier circuit is a full-bridge rectifier circuit;

[0013] Two input terminals of the full-bridge rectifier circuit are connected in series on the input line.

[0014] As an alternative solution, in the above controllable current-limiting reactance protection device, it further includes: a third resistor;

[0015] The third resistor is connected in parallel between the first end and the second end of the second switch tube.

[0016] As an alternative solution, in the above controllable current-limiting reactance protection device, the turns ratio of the primary coil to the secondary coil is adjustable.

[0017] To solve the above technical problems, the present application provides a control method for a controllable current-limiting reactance protection device, which is applied to a controllable current-limiting reactance protection device. The controllable current-limiting reactance protection device includes: a fault monitoring and control module, a rectification module, and a reactance adjustment module; the fault monitoring and control module is connected to the line where the transformer is connected to the power grid, and collects the working state of the power grid circuit; the reactance adjustment module includes a primary coil and a secondary coil with an iron magnetic core, a first switch tube, a second switch tube, a first resistor, and a second resistor; the fault monitoring and control module is connected to the control end of the first switch tube and the control end of the second switch tube; the input end of the rectification module is connected to the input line, the first output end of the rectification module is connected to the first end of the first switch tube and the first end of the first resistor, the second end of the first switch tube and the second end of the first resistor are connected to the first end of the primary coil; the second output end of the rectification module is connected to the second end of the primary coil; the first end of the secondary coil is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the first end of the second resistor, and the second end of the secondary coil is connected to the second end of the second resistor;

[0018] The method includes:

[0019] Obtain the working state of the power grid circuit;

[0020] When the working state of the power grid circuit is in the normal working state, control the first switch tube to close and the second switch tube to open;

[0021] When the working state of the power grid circuit is in a fault state, control the first switch tube and the second switch tube to open.

[0022] As an alternative solution, in the above control method of the controllable current-limiting reactance protection device, when the working state of the power grid circuit is in a fault state, controlling the first switch tube and the second switch tube to open includes:

[0023] When the working state of the power grid circuit is in a fault state, control the first switch tube and the second switch tube to open for a first preset time;

[0024] After controlling the first switch tube and the second switch tube to open when the working state of the power grid circuit is in a fault state, it further includes:

[0025] Control the first switch tube to open and the second switch tube to close for a second preset time; wherein, the sum of the first preset time and the second preset time is not greater than one switching period;

[0026] Return to the step of controlling the first switch tube and the second switch tube to open for a first preset time in the next switching period.

[0027] To solve the above technical problem, the present application further provides an electronic device, including:

[0028] A memory for storing a computer program;

[0029] A processor for executing the computer program to implement the above control method of the controllable current-limiting reactance protection device.

[0030] To solve the above technical problem, the present application further provides a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the above control method of the controllable current-limiting reactance protection device is implemented.

[0031] The controllable current-limiting reactance protection device provided by this application can greatly reduce the rising rate and the first peak value of the fault current by monitoring the working state of the power grid circuit in real time and quickly controlling the on and off of the switching tube to adjust the impedance of the access circuit, avoiding damage to the energy storage system and the distribution transformer. Since the switching speed of the switching tube is much higher than that of the mechanical switch, and this application does not require analysis and processing of the fault signal, directly controlling the on and off of the switching tube also improves the fault handling speed, providing effective current-limiting protection for the energy storage type distribution transformer within a short time after the fault occurs, being unaffected by the operation delay, significantly improving the reliability and stability of the energy storage type distribution transformer in the microgrid environment, and providing a strong guarantee for the safe and stable operation of the power system.

[0032] In addition, this application also provides a control method, an electronic device, and a storage medium, corresponding to the above controllable current-limiting reactance protection device, with the same effect. Brief Description of the Drawings

[0033] In order to more clearly illustrate the embodiments of this application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of this application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is the circuit diagram of a controllable current-limiting reactance protection device provided by an embodiment of this application;

[0035] Figure 2 It is the schematic diagram of the equivalent circuit in a normal state provided by an embodiment of this application;

[0036] Figure 3 It is the schematic diagram of the equivalent circuit in a fault state provided by an embodiment of this application;

[0037] Figure 4 It is the schematic diagram of the equivalent circuit in a recovery state provided by an embodiment of this application;

[0038] Figure 5 It is the flowchart of another control method of the controllable current-limiting reactance protection device provided by an embodiment of this application;

[0039] Figure 6 It is the structure diagram of another electronic device provided by an embodiment of this application. Detailed Embodiments

[0040] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the protection scope of the present application.

[0041] The core of the present application is to provide a controllable current-limiting reactance protection device, a control method, an electronic device, and a medium.

[0042] In order to enable those skilled in the art to better understand the solution of the present application, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0043] The controllable current-limiting reactance protection device of the present application is particularly applicable to the field of fault protection of energy storage distribution transformers, especially in a microgrid environment, where the energy storage distribution transformer integrates an advanced energy storage system (such as battery technology) and realizes real-time monitoring and control of the power system through an intelligent power management system. In this environment, the power system may face complex management challenges, such as the intermittency and uncertainty of renewable energy (solar energy, wind energy), as well as the peaks and valleys of power demand. Therefore, the protection device needs to have the ability to respond quickly, be highly reliable, and flexibly adjust the fault current.

[0044] The embodiment of the present application provides a controllable current-limiting reactance protection device, as Figure 1 shown, including: a fault monitoring and control module, a rectification module, and a reactance adjustment module; the fault monitoring and control module is connected to the line where the transformer is connected to the power grid to collect the working state of the power grid circuit; the reactance adjustment module includes a main coil and a secondary coil with an iron magnetic core, a first switch tube S1, a second switch tube S2, a first resistor R1, and a second resistor R2;

[0045] The fault monitoring and control module is connected to the control ends of the first switch tube S1 and the second switch tube S2; the input end of the rectification module is connected to the input line, the first output end of the rectification module is connected to the first end of the first switch tube S1 and the first end of the first resistor R1, the second end of the first switch tube S1 and the second end of the first resistor R1 are connected to the first end of the main coil; the second output end of the rectification module is connected to the second end of the main coil; the first end of the secondary coil is connected to the first end of the second switch tube S2, the second end of the second switch tube S2 is connected to the first end of the second resistor R2, and the second end of the secondary coil is connected to the second end of the second resistor R2;

[0046] The fault monitoring and control module controls the conduction and cut-off of the first switch tube S1 and the second switch tube S2 according to the working state of the power grid circuit, and adjusts the magnitude of the access impedance.

[0047] The fault monitoring and control module mentioned in the embodiments of this application may use a high-performance microprocessor or a digital signal processor (DSP) as the core, and is equipped with current transformers and voltage transformers to collect the operating status of the power grid circuit. Or other current sensors and voltage sensors are used to monitor the circuit status.

[0048] By monitoring the grid current and voltage, it is judged whether there are fault conditions such as overcurrent and short circuit, and corresponding feedback signals can be sent according to the fault type.

[0049] This module is connected to the control terminals of the first switching transistor S1 and the second switching transistor S2, and controls the conduction and cutoff of the switching transistors by sending control signals.

[0050] The rectification module may adopt a full-bridge rectifier circuit, a half-bridge rectifier circuit, or a voltage-doubling rectifier circuit composed of four diodes to convert the input alternating current into direct current. It provides a stable DC power supply for the reactance regulation module to ensure the normal operation of the reactor. The rectification module can adopt other forms of rectifier circuits as long as it can meet the requirement of providing a stable DC power supply for the reactance regulation module.

[0051] The reactance regulation module includes a primary coil and a secondary coil with an iron magnetic core, a first switching transistor S1, a second switching transistor S2, a first resistor R1, and a second resistor R2. The impedance connected to the circuit can be adjusted by controlling the conduction and cutoff of the switching transistors, thereby limiting the fault current.

[0052] The primary coil and the secondary coil: form a transformer structure for realizing magnetic coupling and impedance transformation. The access and removal of the impedance are realized by controlling the on and off of the switching transistor control circuit.

[0053] By controlling the conduction and cutoff of the switching transistors, the impedance of the circuit can be changed, thereby regulating the fault current. Specifically, in the normal state: when no fault occurs, the fault monitoring and control module only continuously gives a trigger signal to the first switching transistor S1 to keep it continuously conducting, and the second switching transistor S2 is cut off. Figure 2 This is a schematic diagram of an equivalent circuit in the normal state provided by the embodiments of this application, as Figure 2 shown. At this time, the direct current output by the rectification module flows into the primary coil after passing through the first switching transistor S1 and the first resistor R1. Due to the magnetic coupling effect between the primary coil and the secondary coil, no induced current is generated in the secondary coil. Therefore, the impedance of the entire circuit is small, and the influence on the normal current is small.

[0054] When a fault occurs in the microgrid, after the fault monitoring and control module detects an abnormal current or voltage signal, it controls the two switching transistors to turn off. Figure 3 This is a schematic diagram of an equivalent circuit in the fault state provided by the embodiments of this application, as Figure 3As shown, at this time, since the current in the primary coil suddenly interrupts, an induced current will be generated in the secondary coil, and the energy will be consumed through the second resistor R2, thereby increasing the equivalent impedance of the circuit and limiting the fault current.

[0055] After the current limiting protection, in order to protect the device and prepare for the next fault protection, the fault monitoring and control module only gives a trigger signal to the second switch tube S2 to keep it continuously conducting, and the first switch tube S1 remains off. Figure 4 The schematic diagram of the equivalent circuit in the recovery state provided by the embodiment of the present application is as Figure 4 shown. At this time, the magnetization state of the iron core is restored by the reverse magnetic flux generated by the induced current in the secondary coil, preparing for limiting the fault current in the next switching cycle.

[0056] In this embodiment, the switch tube can adopt other types of semiconductor devices, such as Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET), thyristor, Insulate-Gate Bipolar Transistor (IGBT).

[0057] In order to ensure that the protection device can quickly respond to faults and effectively limit the fault current, parameters such as the response time of the fault monitoring and control module, the switching speed of the switch tube, and the impedance transformation range of the reactance regulation module need to be limited.

[0058] This solution does not limit specific features such as the turn ratio of the primary coil to the secondary coil in the reactance regulation module, the type of the switch tube, or the resistance value of the resistor. These features can be flexibly selected and adjusted according to actual application requirements.

[0059] Through the controllable current limiting reactance protection device provided by the embodiment of the present application, by real-time monitoring the working state of the power grid circuit and quickly controlling the on and off of the switch tube, and by adjusting the impedance size of the access circuit, the rising rate and the first peak value of the fault current can be greatly reduced, avoiding damage to the energy storage system and the distribution transformer, and effectively providing current limiting protection for the energy storage type distribution transformer within a short time after the fault occurs. The switching speed of the switch tube is much higher than that of the mechanical switch, and the present application does not need to analyze and process the fault signal, directly controlling the on and off of the switch tube, which also improves the fault handling speed, is not affected by the operation delay, significantly improves the reliability and stability of the energy storage type distribution transformer in the microgrid environment, and provides a strong guarantee for the safe and stable operation of the power system.

[0060] According to the above embodiment, in a specific embodiment, the fault monitoring and control module includes: a controller, a current transformer, and a voltage transformer;

[0061] The current transformer and the voltage transformer are connected to the power grid. The current transformer is used to detect the current value of the power grid; the voltage transformer is used to monitor the voltage value of the power grid;

[0062] The current transformer and the voltage transformer are connected to the controller.

[0063] The controller, as the core processing unit, receives the power grid current and voltage data collected by the current transformer and the voltage transformer, analyzes the power grid state, and generates a control signal according to the preset logic to control the conduction and cut-off of the first switch tube S1 and the second switch tube S2.

[0064] The current transformer (Current Transformer, CT) detects the current value of the power grid and converts the current signal into a low-level signal that can be processed by the controller, which is used to determine whether there is an overcurrent or short-circuit fault. It usually adopts a toroidal core structure, has high precision and a wide dynamic range, and is suitable for detecting different current levels.

[0065] The voltage transformer (Voltage Transformer, VT) monitors the voltage value of the power grid and converts the voltage signal into a low-level signal that can be processed by the controller, which is used to determine whether there is an overvoltage or undervoltage fault. It can adopt an electromagnetic or capacitive voltage transformer, which has high insulation and stability.

[0066] The current transformer and the voltage transformer are connected to the power grid, directly connected to the power grid line, and collect current and voltage data in real time. The collected current and voltage data are transmitted to the controller through the signal line.

[0067] In the normal state, the controller continuously monitors the current and voltage data. If no abnormality is detected, the first switch tube S1 is kept conducting and the second switch tube S2 is turned off to ensure that the circuit impedance is small. When the controller detects abnormalities such as overcurrent, short circuit, or overvoltage, it immediately turns off the first switch tube S1 and the second switch tube S2, and increases the circuit impedance through the reactance adjustment module to limit the fault current.

[0068] Through the above structure, the fault monitoring and control module can realize the real-time monitoring and rapid response to the power grid state, ensure that the controllable current-limiting reactance protection device effectively limits the fault current when a fault occurs, and protects the safety of power equipment.

[0069] According to the above embodiment, in a specific embodiment, the rectifier circuit is a full-bridge rectifier circuit;

[0070] The two input terminals of the full-bridge rectifier circuit are connected in series on the input line.

[0071] The full - bridge rectifier circuit consists of four diodes (D1, D2, D3, D4), forming two input terminals and two output terminals. The two input terminals are connected in series on the input line to receive AC input; the two output terminals are respectively connected to the input terminal of the reactance regulation module to provide rectified DC power.

[0072] Through rectification in the positive and negative half - cycles, the full - bridge rectifier circuit converts AC into pulsating DC, and the output terminal voltage is a unidirectional pulsating waveform. It converts the AC on the input line into DC to provide a stable DC power supply for the reactance regulation module.

[0073] Through the above design, the full - bridge rectifier circuit can efficiently and stably convert AC into DC, providing reliable power support for the controllable current - limiting reactance protection device.

[0074] According to the above - mentioned embodiment, in a specific embodiment, it further includes: a third resistor R3;

[0075] The third resistor R3 is connected in parallel between the first end and the second end of the second switching transistor S2.

[0076] The third resistor R3 is connected in parallel between the first end and the second end of the second switching transistor S2, and is used to provide a current path when the second switching transistor S2 is turned off, avoiding damage to the switching transistor due to excessive voltage.

[0077] When the second switching transistor S2 is turned off, the third resistor R3 acts as a discharge resistor to absorb the residual energy at both ends of the switching transistor, preventing voltage spikes. It improves the stability and reliability of the circuit, extends the service life of the second switching transistor S2, effectively reduces the voltage stress of the switching transistor, and improves the safety of the system.

[0078] According to the above - mentioned embodiment, in a specific embodiment, the turns ratio of the primary coil to the secondary coil is adjustable.

[0079] In this embodiment, the turns ratio can be adjusted by setting multiple taps on the primary coil and the secondary coil, and changing the effective number of turns of the coil by switching the tap positions. Or by installing sliding contacts on the coil and moving the contact positions mechanically or electrically to dynamically adjust the effective number of turns of the coil.

[0080] It is also possible to use multiple independent windings and select different combinations of windings through switches to achieve flexible adjustment of the turns ratio.

[0081] By adjusting the turns ratio, the impedance characteristics of the reactance regulation module can be changed to adapt to different grid conditions and fault conditions. It improves the adaptability of the device, enabling it to handle multiple fault scenarios, optimizes the current - limiting effect, and ensures rapid and effective limitation of fault current when a fault occurs.

[0082] Through the above design, the function of adjustable turns ratio between the primary coil and the secondary coil significantly improves the flexibility and adaptability of the controllable current-limiting reactance protection device, enabling it to better meet the requirements of complex power systems.

[0083] The embodiment of the present application also provides a control method for a controllable current-limiting reactance protection device, which is applied to the controllable current-limiting reactance protection device. The controllable current-limiting reactance protection device includes: a fault monitoring and control module, a rectification module, and a reactance adjustment module; the fault monitoring and control module is connected to the line where the transformer is connected to the power grid to collect the working state of the power grid circuit; the reactance adjustment module includes a primary coil and a secondary coil with an iron magnetic core, a first switch tube S1, a second switch tube S2, a first resistor R1, and a second resistor R2; the fault monitoring and control module is connected to the control ends of the first switch tube S1 and the second switch tube S2; the input end of the rectification module is connected to the input line, the first output end of the rectification module is connected to the first end of the first switch tube S1 and the first end of the first resistor R1, the second end of the first switch tube S1 and the second end of the first resistor R1 are connected to the first end of the primary coil; the second output end of the rectification module is connected to the second end of the primary coil; the first end of the secondary coil is connected to the first end of the second switch tube S2, the second end of the second switch tube S2 is connected to the first end of the second resistor R2, and the second end of the secondary coil is connected to the second end of the second resistor R2;

[0084] As Figure 5 shown, the method includes:

[0085] S11: Obtain the working state of the power grid circuit;

[0086] S12: When the working state of the power grid circuit is in the normal working state, control the first switch tube to close and the second switch tube to open;

[0087] S13: When the working state of the power grid circuit is a fault state, control the first switch tube and the second switch tube to open.

[0088] In step S11 of this embodiment, the working state of the power grid circuit is obtained, and the working state of the power grid circuit, including parameters such as current and voltage, is collected in real time through a sensor connected to the line where the transformer is connected to the power grid.

[0089] In step S12, when the working state of the power grid circuit is in the normal working state, control the first switch tube S1 to close and the second switch tube S2 to open. When the power grid circuit is in the normal working state, the fault monitoring and control module sends a signal to control the first switch tube S1 to close, so that the direct current output by the rectification module passes through the primary coil, while the second switch tube S2 remains in the open state. At this time, the device does not provide additional impedance.

[0090] Specifically, the first switching transistor S1 and the second switching transistor S2 can be IGBTs, which have the characteristics of high switching speed and low conduction loss.

[0091] In step S13, when the power grid circuit is in a fault state, control the first switching transistor S1 and the second switching transistor S2 to turn off. When a fault occurs in the power grid circuit, the fault monitoring and control module quickly detects an abnormal signal and sends an instruction to control the first switching transistor S1 and the second switching transistor S2 to turn off simultaneously.

[0092] The operation of turning off the first switching transistor S1 and the second switching transistor S2 is actually to connect an equivalent large impedance to the circuit, and reduce the fault current through the limiting effect of the DC reactor. In a fault state, the device can quickly increase the equivalent impedance of the circuit, thereby limiting the magnitude of the fault current and protecting the energy storage battery system and the transformer from damage.

[0093] Through the control method of the controllable current-limiting reactance protection device provided by the embodiments of the present application, by real-time monitoring the working state of the power grid circuit and quickly controlling the on and off of the switching transistors, and by adjusting the magnitude of the impedance connected to the circuit, the rising rate and the first peak value of the fault current can be greatly reduced, avoiding damage to the energy storage system and the distribution transformer, and being able to provide effective current-limiting protection for the energy storage type distribution transformer within a short time after the fault occurs. The switching speed of the switching transistors is much higher than that of mechanical switches, and the present application does not need to analyze and process the fault signal, directly controls the on and off of the switching transistors, also improves the fault handling speed, is not affected by operation delay, significantly improves the reliability and stability of the energy storage type distribution transformer in the microgrid environment, and provides a strong guarantee for the safe and stable operation of the power system.

[0094] According to the above embodiments, in a specific embodiment, when the power grid circuit is in a fault state, controlling the first switching transistor S1 and the second switching transistor S2 to turn off includes:

[0095] When the power grid circuit is in a fault state, control the first switching transistor S1 and the second switching transistor S2 to turn off for a first preset time;

[0096] When the power grid circuit is in a fault state, after controlling the first switching transistor S1 and the second switching transistor S2 to turn off, it further includes:

[0097] Control the first switching transistor S1 to turn off and the second switching transistor S2 to turn on for a second preset time; wherein, the sum of the first preset time and the second preset time is not greater than one switching period;

[0098] Return to the step of controlling the first switching transistor S1 and the second switching transistor S2 to turn off for a first preset time T1 in the next switching period.

[0099] In this embodiment, when the grid circuit is in a fault state, the first switch tube S1 and the second switch tube S2 are controlled to be disconnected for a first preset time, which refers to the time for the switch tube to maintain the disconnected state after being completely disconnected. The specific time can be adjusted according to the attenuation speed of the grid fault current and the demagnetization time of the DC reactor.

[0100] A switching cycle refers to a complete switching control cycle, which is usually 10-20ms (corresponding to a 50Hz or 100Hz power system operating frequency cycle).

[0101] The fault monitoring control module collects the grid current and voltage signals through a high-speed analog-to-digital converter (ADC). Once a fault is detected, the timer is triggered immediately to control the switch tube to disconnect and start timing.

[0102] The turn-off speed of the first switch tube S1 and the second switch tube S2 needs to match the first preset time requirement. The switch tube is completely disconnected within the first preset time, so that the equivalent large impedance formed by the main coil and the secondary coil is connected to the circuit to quickly limit the fault current.

[0103] Since S1 is disconnected, is connected to the circuit, at this time The equivalent impedance is The increase in equivalent impedance increases the limiting effect on the fault current, achieving the effect of current limiting protection and reducing the fault current.

[0104] Step S14 controls the first switch tube S1 to be turned off, and the second switch tube S2 to be turned on for a second preset time. The second preset time T2 refers to the time when the second switch tube S2 is turned on. The fault monitoring control module immediately turns on the second switch tube S2 (outputs a high-level signal through the drive circuit) after the first preset time ends, while keeping the first switch tube S1 turned off. S2 is continuously turned on, S1 is turned off, and the equivalent circuit is as follows Figure 4 As shown, switch S1 is open and S2 is closed. This state is called the recovery state. In this state, By generating reverse flux to restore the core, the DC reactor will be restored to continue limiting the fault current in the next switching cycle.

[0105] At the end of each switching cycle (i.e. after T1+T2), the fault monitoring control module resets the timer and re-enters step S13 to form a closed-loop control.

[0106] If the fault is not eliminated, the periodic control can maintain the current limiting effect; if the fault is eliminated, the normal working mode is automatically restored (return to S12). The average switching frequency of the switch tube is reduced through time-sharing control (T1 is disconnected and T2 is closed), thereby extending the life of the device.

[0107] For more precise current limiting adjustment, T1 and T2 can be designed to be dynamically adjustable (calculated in real time according to the magnitude of the fault current), rather than a fixed value.

[0108] Through the above design, this embodiment realizes high-reliability and fast-response current limiting protection in a complex power grid environment, while taking into account the equipment life and system stability.

[0109] Figure 6 The structural diagram of another electronic device provided by an embodiment of this application is as Figure 6 shown. The electronic device includes: a memory 20 for storing a computer program;

[0110] a processor 21 for implementing the steps of the method for obtaining user operation habit information as described in the above embodiment (control method of a controllable current limiting reactance protection device) when executing the computer program.

[0111] The electronic device provided by this embodiment may include, but is not limited to, a smart phone, a tablet computer, a notebook computer, or a desktop computer, etc.

[0112] Among them, the processor 21 may include one or more processing cores, such as a 4-core processor, an 8-core processor, etc. The processor 21 may be implemented in at least one hardware form of a digital signal processor (DSP), a field-programmable gate array (FPGA), or a programmable logic array (PLA). The processor 21 may also include a main processor and a coprocessor. The main processor is a processor for processing data in the wake state, also known as a central processing unit (CPU); the coprocessor is a low-power processor for processing data in the standby state. In some embodiments, the processor 21 may be integrated with a graphics processing unit (GPU), and the GPU is responsible for rendering and drawing the content to be displayed on the display screen. In some embodiments, the processor 21 may further include an artificial intelligence (AI) processor, and the AI processor is used to process computational operations related to machine learning.

[0113] The memory 20 may include one or more computer-readable storage media, which may be non-transitory. The memory 20 may also include high-speed random access memory, as well as non-volatile memory, such as one or more disk storage devices and flash storage devices. In this embodiment, the memory 20 is at least used to store the following computer program 201. After the computer program is loaded and executed by the processor 21, it can implement the relevant steps of the controllable current-limiting reactance protection device control method disclosed in any of the foregoing embodiments. In addition, the resources stored in the memory 20 may also include an operating system 202 and data 203, etc., and the storage method may be transient storage or permanent storage. Among them, the operating system 202 may include Windows, Unix, Linux, etc. The data 203 may include, but is not limited to, the data involved in implementing the controllable current-limiting reactance protection device control method.

[0114] In some embodiments, the electronic device may further include a display screen 22, an input / output interface 23, a communication interface 24, a power supply 25, and a communication bus 26.

[0115] Those skilled in the art can understand that Figure 6 the structure shown in does not constitute a limitation on the electronic device, and it may include more or fewer components than shown in the figure.

[0116] The electronic device provided by the embodiment of the present application includes a memory and a processor. When the processor executes the program stored in the memory, it can implement the following method: the controllable current-limiting reactance protection device control method.

[0117] Finally, the present application also provides an embodiment corresponding to a computer-readable storage medium. A computer program is stored on the computer-readable storage medium, and when the computer program is executed by the processor, it implements the steps recorded in the controllable current-limiting reactance protection device control method embodiment as described above.

[0118] It can be understood that if the method in the above embodiments is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on such an understanding, the technical solution of the present application, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and executes all or part of the steps of the methods described in the various embodiments of the present application. And the foregoing storage medium includes: various media such as USB flash drives, mobile hard disks, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical discs that can store program codes.

[0119] The computer-readable storage medium provided in this embodiment stores a computer program, and when the processor executes the program, the following method can be implemented: a control method for a controllable current-limiting reactance protection device.

[0120] The controllable current-limiting reactance protection device, control method, electronic device, and medium provided in the present application have been introduced in detail above. Each embodiment in the specification is described in a progressive manner, and the key point of each embodiment is the difference from other embodiments. The same or similar parts among the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the description of the method part. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the protection scope of the claims of the present application.

[0121] It should also be noted that in this specification, relational terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the term "comprising", "including" or any other variant thereof is intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or further includes elements inherent to such process, method, article or device. Without further limitation, the element defined by the statement "including one..." does not exclude the existence of another identical element in the process, method, article or device including the said element.

Claims

1. A controllable current limiting reactance protection device, characterized in that: include: A fault monitoring control module, a rectifier module and a reactance adjustment module; the fault monitoring control module is connected to the line connecting the transformer and the power grid to collect the working status of the power grid circuit; the reactance adjustment module includes a primary coil and a secondary coil with a ferromagnetic core, a first switch tube, a second switch tube, a first resistor, and a second resistor; The fault monitoring control module is connected to the control end of the first switch tube and the control end of the second switch tube; the input end of the rectifier module is connected to the input line, the first output end of the rectifier module is connected to the first end of the first switch tube and the first end of the first resistor, the second end of the first switch tube and the second end of the first resistor are connected to the first end of the main coil; the second output end of the rectifier module is connected to the second end of the main coil; the first end of the secondary coil is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the first end of the second resistor, and the second end of the secondary coil is connected to the second end of the second resistor; The fault monitoring control module controls the on and off of the first switch tube and the second switch tube according to the working state of the power grid circuit, and adjusts the access impedance.

2. The controllable current limiting reactance protection device according to claim 1, characterized in that: The fault monitoring control module includes: a controller, a current transformer and a voltage transformer; The current transformer and the voltage transformer are connected to the power grid, the current transformer is used to detect the current value of the power grid; the voltage transformer is used to monitor the voltage value of the power grid; The current transformer and the voltage transformer are connected to the controller.

3. The controllable current limiting reactance protection device according to claim 1, characterized in that: The rectifier circuit is a full-bridge rectifier circuit; The two input terminals of the full-bridge rectifier circuit are connected in series on the input line.

4. The controllable current limiting reactance protection device according to claim 1, characterized in that: Also includes: The third resistor; The third resistor is connected in parallel between the first end and the second end of the second switch tube.

5. The controllable current limiting reactance protection device according to any one of claims 1 to 4, characterized in that: The turns ratio between the primary coil and the secondary coil is adjustable.

6. A control method for a controllable current limiting reactance protection device, characterized in that: Applied to a controllable current-limiting reactance protection device, the controllable current-limiting reactance protection device comprises: a fault monitoring control module, a rectifier module and a reactance adjustment module; the fault monitoring control module is connected to the line connecting the transformer and the power grid to collect the working state of the power grid circuit; the reactance adjustment module comprises a main coil and a secondary coil with a ferromagnetic core, a first switch tube, a second switch tube, a first resistor and a second resistor; the fault monitoring control module is connected to the control end of the first switch tube and the control end of the second switch tube; the input end of the rectifier module is connected to the input line, the first output end of the rectifier module is connected to the first end of the first switch tube and the first end of the first resistor, the second end of the first switch tube and the second end of the first resistor are connected to the first end of the main coil; the second output end of the rectifier module is connected to the second end of the main coil; the first end of the secondary coil is connected to the first end of the second switch tube, the second end of the second switch tube is connected to the first end of the second resistor, and the second end of the secondary coil is connected to the second end of the second resistor; The method comprises: Obtain the working status of the power grid circuit; When the grid circuit is in a normal working state, the first switch tube is controlled to be closed and the second switch tube is disconnected; When the grid circuit is in a fault state, the first switch tube and the second switch tube are controlled to be disconnected.

7. The control method of the controllable current limiting reactance protection device according to claim 6, characterized in that: When the working state of the power grid circuit is a fault state, controlling the first switch tube and the second switch tube to be disconnected includes: When the working state of the power grid circuit is a fault state, controlling the first switch tube and the second switch tube to be disconnected for a first preset time; When the working state of the power grid circuit is a fault state, after controlling the first switch tube and the second switch tube to be disconnected, the method further includes: Controlling the first switch tube to be disconnected and the second switch tube to be closed for a second preset time; wherein the sum of the first preset time and the second preset time is not greater than one switching cycle; In the next switching cycle, the step of controlling the first switch tube and the second switch tube to be disconnected for a first preset time is returned.

8. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor is used to execute the computer program to implement the control method of the controllable current limiting inductor protection device as described in claim 6 or 7.

9. A computer-readable storage medium, characterized in that: Used to store computer programs; wherein, when the computer program is executed by a processor, the control method for controlling a controllable current limiting reactor protection device as described in claim 6 or 7 is implemented.

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