A leakage-proof current limiting reactor

Abstract

The utility model belongs to the technical field of electric reactor, concretely relates to a kind of leakage prevention current limiting reactor, including main circuit, leakage detection protection module, current limiting module, voltage acquisition module, controller and IGBT drive module;The input end of the main circuit is A end, and the output end is B end, circuit breaker CB1 and circuit breaker CB2 are provided in the main circuit;The leakage detection protection module includes current transformer TA1, rectifier bridge UR1, attraction coil KA1;The current transformer TA1 is sleeved on the wire of the main circuit, and its output end is connected with the input end of the rectifier bridge UR1;The output end of the rectifier bridge UR1 is connected with the coil of the attraction coil KA1;The normally open contact of the attraction coil KA1 is parallelly connected with the circuit breaker CB1, and the leakage detection protection module is connected with the main circuit, for detecting main circuit leakage and triggering protection action.

Description

Technical Field

[0001] This utility model belongs to the field of reactor technology, specifically relating to a leakage current limiting reactor. Background Technology

[0002] DC power systems in shipboard integrated power systems are increasingly used due to their high efficiency and good performance. However, the protection design of shipboard DC power systems faces the challenge that traditional fault detection and protection technologies based on conventional circuit breakers are no longer applicable. In shipboard integrated power systems, reactors are used to limit current in the circuit and also serve as filters. However, existing reactors lack effective leakage current detection and protection functions during use; when leakage occurs, it may lead to safety accidents. Furthermore, their current limiting effect is not ideal and cannot adequately handle various abnormal current conditions. Therefore, this invention proposes a leakage current limiting reactor. Utility Model Content

[0003] In view of the above-mentioned shortcomings in the prior art, the present invention provides a leakage current limiting reactor to solve the problems in the background art.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A leakage current limiting reactor includes a main circuit, a leakage current detection and protection module, a current limiting module, a voltage acquisition module, a controller, and an IGBT drive module; The main circuit has an input terminal A and an output terminal B. Circuit breakers CB1 and CB2 are installed in the main circuit. Secondly, the leakage current detection and protection module includes a current transformer TA1, a rectifier bridge UR1, and a coil KA1. The current transformer TA1 is sleeved on the conductor of the main circuit, and its output terminal is connected to the input terminal of the rectifier bridge UR1. The output terminal of the rectifier bridge UR1 is connected to the coil of the coil KA1. The normally open contact of the coil KA1 is connected in parallel with the circuit breaker CB1. The leakage current detection and protection module is connected to the main circuit and is used to detect leakage current in the main circuit and trigger protection action. Meanwhile, a current limiting module is connected in series in the main circuit to limit abnormal current in the main circuit; The IGBT drive module is connected in series in the main circuit, and its control terminal is connected to the controller. The input terminal of the voltage acquisition module is connected to the output terminal of the main circuit, and the output terminal is connected to the signal input terminal of the controller.

[0005] Furthermore, the leakage current detection and protection module also includes capacitors C2 and C3 and thyristor VT1; capacitor C2 is connected in series between the current transformer TA1 and the rectifier bridge UR1; capacitor C3 is connected in parallel at the output terminal of the rectifier bridge UR1; and thyristor VT1 is connected in series between the rectifier bridge UR1 and the pull-in coil KA1.

[0006] The current limiting module includes a capacitor C1, an inductor L1, and a metal oxide varistor MOV; the capacitor C1 and the inductor L1 are connected in series and then connected to the main circuit; the metal oxide varistor MOV is connected in parallel in the series circuit of the capacitor C1 and the inductor L1.

[0007] Furthermore, the IGBT drive module includes an IGBT module and a drive circuit; the IGBT module includes IGBT transistors Q41 and Q42, which are connected in anti-parallel; the input terminal of the drive circuit is connected to the controller, and the output terminal is connected to the control electrode of the IGBT module.

[0008] The controller is a microcontroller or a PLC controller; the voltage acquisition module is a voltage sensor or a voltage divider resistor network.

[0009] Secondly, the rectifier bridge UR1 is a full-bridge rectifier circuit, consisting of four diodes D1-D4; diodes D1 and D3 are connected in reverse series, and diodes D2 and D4 are connected in reverse series, and the two sets of series circuits are then connected in parallel to form a rectifier circuit.

[0010] Compared with the prior art, this utility model has the following advantages: 1. This utility model improves the accuracy of leakage current detection and the reliability of protection action by dividing the leakage current detection and protection module into three sub-units: current sensing, signal processing, and actuator. The current limiting module adopts a combination of LC passive current limiting and IGBT active current limiting, which ensures both steady-state current limiting effect and rapid response to transient current anomalies. The independent design of each module facilitates maintenance and replacement, reducing subsequent operation and maintenance costs. Furthermore, the use of the KA1 coil to directly drive the circuit breaker CB1 reduces intermediate links compared to relays, resulting in faster response speed and further improving the timeliness of leakage current protection. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the overall circuit structure of an embodiment of the leakage current limiting reactor of this utility model; Figure 2 This is a schematic diagram of the leakage protection circuit of an embodiment of the leakage current limiting reactor of this utility model. Detailed Implementation

[0012] To enable those skilled in the art to better understand this utility model, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0013] The accompanying drawings are for illustrative purposes only and are schematic diagrams, not actual pictures. They should not be construed as limiting the present invention. To better illustrate the embodiments of the present invention, some parts in the drawings may be omitted, enlarged, or reduced, and do not represent the actual product dimensions. It is understandable to those skilled in the art that some well-known structures and their descriptions may be omitted in the drawings.

[0014] In the accompanying drawings of this utility model, the same or similar reference numerals correspond to the same or similar components. In the description of this utility model, it should be understood that if terms such as "upper," "lower," "left," "right," "inner," and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the drawings are only for illustrative purposes and should not be construed as limiting this utility model. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0015] In the description of this utility model, unless otherwise explicitly specified and limited, the term "connection" or similar designation indicating the connection relationship between components should be interpreted broadly. For example, it can refer to a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example

[0016] like Figure 1-2 As shown, a leakage current limiting reactor includes a main circuit, a leakage current detection and protection module, a current limiting module, a voltage acquisition module, a controller, and an IGBT drive module. The main circuit has an input terminal A and an output terminal B. Circuit breakers CB1 and CB2 are installed in the main circuit. Secondly, the leakage current detection and protection module includes a current transformer TA1, a rectifier bridge UR1, and a coil KA1. The current transformer TA1 is sleeved on the conductor of the main circuit, and its output terminal is connected to the input terminal of the rectifier bridge UR1. The output terminal of the rectifier bridge UR1 is connected to the coil of the coil KA1. The normally open contact of the coil KA1 is connected in parallel with the circuit breaker CB1. The leakage current detection and protection module is connected to the main circuit and is used to detect leakage current in the main circuit and trigger protection action. Meanwhile, a current limiting module is connected in series in the main circuit to limit abnormal current in the main circuit; The IGBT drive module is connected in series in the main circuit, and its control terminal is connected to the controller. The input terminal of the voltage acquisition module is connected to the output terminal of the main circuit, and the output terminal is connected to the signal input terminal of the controller.

[0017] Furthermore, the leakage current detection and protection module also includes capacitors C2 and C3 and thyristor VT1; capacitor C2 is connected in series between the current transformer TA1 and the rectifier bridge UR1; capacitor C3 is connected in parallel at the output terminal of the rectifier bridge UR1; and thyristor VT1 is connected in series between the rectifier bridge UR1 and the pull-in coil KA1.

[0018] The current limiting module includes a capacitor C1, an inductor L1, and a metal oxide varistor MOV; the capacitor C1 and the inductor L1 are connected in series and then connected to the main circuit; the metal oxide varistor MOV is connected in parallel in the series circuit of the capacitor C1 and the inductor L1.

[0019] Furthermore, the IGBT drive module includes an IGBT module and a drive circuit; the IGBT module includes IGBT transistors Q41 and Q42, which are connected in anti-parallel; the input terminal of the drive circuit is connected to the controller, and the output terminal is connected to the control electrode of the IGBT module.

[0020] The controller is a microcontroller or a PLC controller; the voltage acquisition module is a voltage sensor or a voltage divider resistor network.

[0021] Secondly, the rectifier bridge UR1 is a full-bridge rectifier circuit, consisting of four diodes D1-D4; diodes D1 and D3 are connected in reverse series, and diodes D2 and D4 are connected in reverse series, and the two sets of series circuits are then connected in parallel to form a rectifier circuit.

[0022] like Figures 1-2As shown, the working principle of this utility model is as follows: In the leakage current detection and protection module, the current transformer TA1 adopts a toroidal iron core structure, and the main circuit conductor passes through the center of the iron core. When the main circuit is working normally, the current of the live wire and the neutral wire are equal in magnitude and opposite in direction, and the induced electromotive force on the secondary side of the current transformer TA1 cancels each other out. When leakage occurs, the zero-sequence current induces a current on the secondary side of the current transformer TA1, which is filtered by capacitor C2 and then enters the rectifier bridge UR1. The rectifier bridge UR1 converts the alternating current into direct current, which is smoothed and filtered by capacitor C3 and then applied to the anode of the thyristor VT1. When the voltage reaches the thyristor trigger threshold, the thyristor VT1 conducts, energizing the coil KA1. The coil KA1 generates electromagnetic force to drive the circuit breaker CB1 to operate, cutting off the main circuit.

[0023] In the current limiting module, capacitor C1 is a high-frequency non-inductive capacitor, and inductor L1 uses a nanocrystalline alloy core. The resonant frequency of the LC circuit formed by the two matches the fundamental frequency of the power grid, which can effectively suppress the rate of increase of short-circuit current. The operating voltage of the metal oxide varistor (MOV) is set to 1.5-2 times the rated voltage of the power grid. When an overvoltage occurs in the line, the resistance of the MOV drops sharply, clamping the voltage within a safe range and diverting part of the current.

[0024] In the IGBT driver module, IGBTs Q41 and Q42 are reverse-conducting devices. The driver circuit includes an optocoupler isolation unit and a gate drive unit. The controller adjusts the IGBT conduction angle through a PWM signal to dynamically limit the main circuit current. The voltage acquisition module monitors the voltage at the B terminal in real time and transmits it to the controller. When an abnormal voltage is detected, the controller quickly shuts off the IGBT module through the driver circuit, forming a dual protection system in conjunction with the current limiting module.

[0025] The above are merely embodiments of this utility model. The circuits, electronic components, and modules involved are all prior art, fully achievable by those skilled in the art, and require no further explanation. The content protected by this application does not involve improvements to the software or methods. Commonly known structures and characteristics in the solution are not described in detail here. Those skilled in the art are aware of all common technical knowledge in the field to which this utility model pertains prior to the application date or priority date, are able to access all existing technologies in that field, and possess the ability to apply conventional experimental methods prior to that date. Those skilled in the art can, under the guidance of this application, improve and implement this solution in conjunction with their own capabilities. Some typical known structures or methods should not be obstacles for those skilled in the art to implement this application. It should be noted that those skilled in the art can make several modifications and improvements without departing from the structure of this utility model. These should also be considered within the scope of protection of this utility model, and will not affect the effectiveness of the implementation of this utility model or the practicality of the patent.

Claims

1. A leakage current limiting reactor, characterized in that, It includes the main circuit, leakage current detection and protection module, current limiting module, voltage acquisition module, controller, and IGBT drive module; The main circuit has an input terminal A and an output terminal B. Circuit breakers CB1 and CB2 are installed in the main circuit. The leakage current detection and protection module includes a current transformer TA1, a rectifier bridge UR1, and a pull-in coil KA1. The current transformer TA1 is sleeved on the conductor of the main circuit, and its output terminal is connected to the input terminal of the rectifier bridge UR1. The output terminal of the rectifier bridge UR1 is connected to the coil of the pull-in coil KA1. The normally open contact of the pull-in coil KA1 is connected in parallel with the circuit breaker CB1. The leakage current detection and protection module is connected to the main circuit and is used to detect leakage current in the main circuit and trigger protection action. The current limiting module is connected in series in the main circuit to limit abnormal current in the main circuit; The IGBT drive module is connected in series in the main circuit, and its control terminal is connected to the controller. The input terminal of the voltage acquisition module is connected to the output terminal of the main circuit, and the output terminal is connected to the signal input terminal of the controller.

2. The leakage current limiting reactor according to claim 1, characterized in that: The leakage current detection and protection module also includes capacitors C2 and C3 and thyristor VT1; capacitor C2 is connected in series between current transformer TA1 and rectifier bridge UR1; capacitor C3 is connected in parallel at the output terminal of rectifier bridge UR1; thyristor VT1 is connected in series between rectifier bridge UR1 and pull-in coil KA1.

3. The leakage current limiting reactor according to claim 1, characterized in that: The current limiting module includes a capacitor C1, an inductor L1, and a metal oxide varistor MOV; the capacitor C1 and the inductor L1 are connected in series and then connected to the main circuit; the metal oxide varistor MOV is connected in parallel in the series circuit of the capacitor C1 and the inductor L1.

4. The leakage current limiting reactor according to claim 1, characterized in that: The IGBT drive module includes an IGBT module and a drive circuit; the IGBT module includes IGBT transistors Q41 and Q42, which are connected in anti-parallel; the input terminal of the drive circuit is connected to the controller, and the output terminal is connected to the control electrode of the IGBT module.

5. The leakage current limiting reactor according to claim 1, characterized in that: The controller is a microcontroller or a PLC controller; the voltage acquisition module is a voltage sensor or a voltage divider resistor network.

6. The leakage current limiting reactor according to claim 2, characterized in that: The rectifier bridge UR1 is a full-bridge rectifier circuit, consisting of four diodes D1-D4; diodes D1 and D3 are connected in reverse series, and diodes D2 and D4 are connected in reverse series, and the two sets of series circuits are then connected in parallel to form a rectifier circuit.

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