Current-limiting protection device for short-circuit fault

Abstract

The invention belongs to the field of short-circuit fault limiting protection, and particularly relates to a current-limiting protection device for a short-circuit fault. The short-circuit fault limiter comprises a circuit monitoring module, a switch control module and a fault current limiting module, the circuit monitoring module is used for acquiring circuit information, judging whether a short-circuit fault occurs in the circuit or not according to the acquired circuit information, generating a fault signal if the short-circuit fault occurs in the circuit, and sending the fault signal to the switch control module; the switch control module is used for controlling the fault current limiting module to be connected to a short-circuit fault circuit according to the received fault signal; the fault current-limiting module is used for carrying out current-limiting protection on a short-circuit fault circuit; according to the technical scheme, the problem that in the prior art, a short-circuit fault limiter cannot achieve line current limiting in time when a short-circuit fault occurs in a line, and normal work of the line is affected can be effectively solved.

Description

Technical Field

[0001] The present application belongs to the field of short-circuit fault limiting protection, and specifically relates to a current limiting protection device for short-circuit faults. Background Art

[0002] In recent years, with the continuous expansion of the scale of power grids, the short-circuit current has also increased year by year, which has had a great impact on the normal operation of the power grid system. In order to ensure the normal operation of the power grid system, certain current limiting measures are taken. The existing current limiting measures mostly use DC networking technology and increase the interrupting capacity of circuit breakers. Although they can limit the short-circuit current to a certain extent, they also bring other problems. When a short-circuit fault occurs in the existing series reactor type FCL, the instantaneous voltage at both ends of the reactor is too high, and the short-circuit fault line current limiting cannot be achieved in time, affecting the normal operation of the line. Summary of the invention

[0003] In order to solve the problem that the short-circuit fault limiter in the prior art cannot realize line current limiting in time when a short-circuit fault occurs in the line, thus affecting the normal operation of the line, a current limiting protection device for short-circuit fault is proposed;

[0004] A current limiting protection device for short circuit faults, comprising: a circuit monitoring module, a switch control module and a fault current limiting module;

[0005] The circuit monitoring module is used to obtain circuit information and determine whether a short-circuit fault occurs in the circuit based on the obtained circuit information. If a short-circuit fault occurs in the circuit, a fault signal is generated and sent to the switch control module; the switch control module is used to control the fault current limiting module to access the short-circuit fault circuit based on the received fault signal; the fault current limiting module is used to access the short-circuit fault circuit and perform current limiting protection on the short-circuit fault circuit.

[0006] Compared with the prior art, the current limiting protection device for short-circuit faults in the present application includes a circuit monitoring module, a switch control module and a fault current limiting module. The circuit monitoring module can automatically detect whether a short-circuit fault occurs in the circuit. The switch control module can enable the fault current limiting module to quickly connect to the circuit when a short-circuit fault occurs in the circuit. The fault current limiting module performs current limiting protection on the short-circuit fault circuit without affecting the normal operation of the line. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 A schematic diagram of the structure of a current limiting protection device for short circuit faults in a specific implementation mode of the present application;

[0008] Figure 2 A circuit diagram of a capacitor charging loop of a current limiting protection device for short circuit faults according to a specific implementation of the present application. DETAILED DESCRIPTION

[0009] Specific implementation method 1: The following will be combined with the attached embodiment of the present invention Figure 1 and attached Figure 2 , illustrate this implementation mode, and clearly and completely describe the technical solutions in the embodiments of the present invention:

[0010] A current limiting protection device for short circuit faults, comprising: a circuit monitoring module, a switch control module and a fault current limiting module;

[0011] The circuit monitoring module is used to obtain circuit information and determine whether a short-circuit fault occurs in the circuit based on the obtained circuit information. If a short-circuit fault occurs in the circuit, a fault signal is generated and sent to the switch control module; the switch control module is used to control the fault current limiting module to access the short-circuit fault circuit based on the received fault signal; the fault current limiting module is used to access the short-circuit fault circuit and perform current limiting protection on the short-circuit fault circuit.

[0012] Specifically, a current limiting protection device for short-circuit faults of the present application obtains circuit information in real time through a circuit monitoring module to determine whether there is a short-circuit fault in the circuit. If there is no short-circuit fault in the circuit, the short-circuit fault limiter consumes almost no active power and does not require any reactive power to maintain its state, and has no effect on the normal operation of the power grid; if there is a short-circuit fault in the circuit, the switch control module quickly controls the fault current limiting module to access the circuit. After the fault current limiting module is connected to the circuit, the short-circuit fault circuit is current-limited, which does not affect the normal operation of the short-circuit fault circuit and is of great significance to the protection of power grid lines.

[0013] Further, the circuit monitoring module includes a data acquisition module and a data processing module;

[0014] The data acquisition module is used to collect circuit information and send the circuit information to the data processing module; the data processing module is used to determine whether a short circuit fault occurs in the circuit according to the received circuit information, and generate a fault signal if a short circuit fault occurs in the circuit; the data processing module is also used to send the generated fault information to the switch control module;

[0015] Specifically, the circuit monitoring module realizes real-time monitoring of the circuit by collecting circuit information, and determines whether a short circuit fault occurs in the circuit based on the circuit information, with high accuracy and fast response speed.

[0016] Further, the circuit information includes a circuit current change amount and a circuit voltage change amount;

[0017] The method by which the data processing module determines whether a short circuit fault occurs in the circuit based on the received circuit information is as follows: simultaneously determine whether the circuit current change exceeds a first threshold or whether the circuit voltage change exceeds a second threshold; if the circuit current change exceeds the first threshold or the circuit voltage change exceeds the second threshold, a short circuit fault occurs in the circuit.

[0018] Specifically, whether a short circuit fault occurs in the circuit is determined by the change in circuit current and circuit voltage, with high accuracy, thus reducing the occurrence of misjudgment.

[0019] Furthermore, the fault current limiting module includes a current limiting inductor and a capacitor charging circuit; the current limiting inductor and the capacitor charging circuit are connected in parallel; the capacitor charging circuit is used to stabilize the short-circuit fault circuit, and the current limiting inductor is used to receive the short-circuit fault current.

[0020] Specifically, the fault current limiting module can effectively realize current limiting protection for short-circuit fault current. When the line is short-circuited, after a short period of voltage stabilization and current conversion in the capacitor charging circuit, the short-circuit current is completely transferred to the current limiting inductor. At this time, the capacitor charging circuit is regarded as an open circuit state, and the equivalent impedance of the device is equal to the current limiting inductor impedance.

[0021] Furthermore, if Figure 2 As shown, the capacitor charging circuit includes a capacitor C, a first voltage stabilizing diode D 1 , the second voltage zener diode D 2 , the third voltage zener diode D 3 , the fourth voltage zener diode D 4 and fuses;

[0022] The first Zener diode D 1 The positive electrode is connected to the first setting point of the fault circuit and the second voltage regulator diode D 2 The cathode is connected to one end of the current limiting inductor L, and the first voltage stabilizing diode D 1 The cathode is connected to the fourth voltage stabilizing diode D 4 The cathode is connected to one end of capacitor C, and the fourth voltage stabilizing diode D 4 The positive electrode is connected to the third voltage stabilizing diode D 3 The cathode is connected to one end of the fuse FU, and the third voltage regulator diode D 3 The anode is connected to the other end of the capacitor C, and the other end of the fuse FU is connected to the other end of the current limiting inductor L and the second setting point of the fault circuit.

[0023] Furthermore, the fault current limiting module also includes a lightning arrester, which is connected in parallel with the current limiting inductor and the capacitor charging circuit respectively, and the lightning arrester is used to prevent overvoltage in the short circuit fault circuit.

[0024] Furthermore, the fault current limiting module further includes a spark gap SG, which is connected in parallel with the current limiting inductor and the capacitor charging loop respectively, and the spark gap SG is used to prevent overvoltage in a short circuit fault circuit.

[0025] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. It should therefore be understood that many modifications may be made to the exemplary embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in a manner different from that described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in other described embodiments.

Claims

1. A current limiting protection device for short circuit fault, characterized in that: include: Circuit monitoring module, switch control module and fault current limiting module; The circuit monitoring module is used to obtain circuit information and determine whether a short circuit fault occurs in the circuit based on the obtained circuit information. If a short circuit fault occurs in the circuit, a fault signal is generated and sent to the switch control module. The switch control module is used to control the fault current limiting module to access the short-circuit fault circuit according to the received fault signal; the fault current limiting module is used to access the short-circuit fault circuit to perform current limiting protection on the short-circuit fault circuit.

2. A current limiting protection device for short circuit fault according to claim 1, characterized in that: The circuit monitoring module includes a data acquisition module and a data processing module; The data acquisition module is used to collect circuit information and send the circuit information to the data processing module; The data processing module is used to determine whether a short circuit fault occurs in the circuit according to the received circuit information, and generate a fault signal if a short circuit fault occurs in the circuit; The data processing module is also used to send the generated fault information to the switch control module.

3. A current limiting protection device for short circuit fault according to claim 2, characterized in that: The circuit information includes the circuit current change amount and the circuit voltage change amount; The method by which the data processing module determines whether a short circuit fault occurs in the circuit based on the received circuit information is as follows: simultaneously determine whether the circuit current change exceeds a first threshold or whether the circuit voltage change exceeds a second threshold; if the circuit current change exceeds the first threshold or the circuit voltage change exceeds the second threshold, a short circuit fault occurs in the circuit.

4. A current limiting protection device for short circuit fault according to claim 1, characterized in that: The fault current limiting module includes a current limiting inductor and a capacitor charging circuit; The current limiting inductor is connected in parallel with the capacitor charging circuit; the capacitor charging circuit is used to stabilize the voltage of the short-circuit fault circuit, and the current limiting inductor is used to receive the short-circuit fault current.

5. A current limiting protection device for short circuit fault according to claim 4, characterized in that: The capacitor charging circuit includes a capacitor, a first voltage stabilizing diode, a second voltage stabilizing diode, a third voltage stabilizing diode, a fourth voltage stabilizing diode and a fuse; The positive electrode of the first Zener diode is respectively connected to the first setting point of the fault circuit, the negative electrode of the second Zener diode and one end of the current limiting inductor, the negative electrode of the first Zener diode is respectively connected to the negative electrode of the fourth Zener diode and one end of the capacitor, the positive electrode of the fourth Zener diode is respectively connected to the negative electrode of the third Zener diode and one end of the fuse, the anode of the third Zener diode is connected to the other end of the capacitor, and the other end of the fuse is connected to the other end of the current limiting inductor and the second setting point of the fault circuit.

6. A current limiting protection device for short circuit fault according to claim 4, characterized in that: The fault current limiting module also includes a lightning arrester, which is connected in parallel with the current limiting inductor and the capacitor charging circuit respectively, and the lightning arrester is used to prevent overvoltage in the short circuit fault circuit.

7. A current limiting protection device for short circuit fault according to claim 4, characterized in that: The fault current limiting module also includes a spark gap, which is connected in parallel with the current limiting inductor and the capacitor charging loop respectively, and the spark gap is used to prevent overvoltage in the short circuit fault circuit.

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