Full-loop direct-current insulation protection circuit breaker

Abstract

The invention belongs to the field of new energy, and particularly relates to a full-loop direct-current insulation protection circuit breaker. The device comprises a direct current insulation protection circuit breaker and a central control box connected with the direct current insulation protection circuit breaker. The central control box displays operation, alarm and fault signals of the main loop and each branch; if the detection data reach or exceed a set judgment value, the circuit breaker executes a fault breaking action; the insulation detection module of the direct-current insulation protection circuit breaker is integrated with the circuit breaker, so that disassembly, assembly and maintenance are simple and convenient; the insulation detection module has detection, alarm, communication and fault protection functions; insulation detection alarm and fault protection functions can be adjusted; and the central control box realizes unified control of data of each branch.

Description

Technical Field

[0001] This application belongs to the field of new energy, specifically relating to a circuit breaker with full-circuit DC insulation protection and a central control box connected thereto. Background Technology

[0002] Existing circuit breakers or disconnectors have the following technical drawbacks: 1. Inverter insulation detection function limitations: It can only detect the insulation status of the main circuit and cannot detect and judge the insulation status of individual branches. 2. Separate insulation detection module limitations: It is complex to install and increases installation space. 3. It cannot perform intelligent control and intelligent display of detection status.

[0003] Therefore, it is necessary to develop a full-circuit DC insulation protection circuit breaker to address the technical deficiencies mentioned in the background art. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this application provides the following technical solution: A full-circuit DC insulation protection circuit breaker includes: a DC insulation protection circuit breaker and a central control box connected thereto; the central control box displays the operation, alarm, and fault signals of the main circuit and each branch; if the detected data reaches or exceeds the set judgment value, the circuit breaker performs a fault disconnection action.

[0005] Preferably, the central control box has a third circuit board inside, and the third circuit board has an indicator light and a third DIP switch; the indicator light is used to display the operation, alarm and fault signals of the main circuit and each branch circuit; the third DIP switch is used to set the judgment value.

[0006] Preferably, the DC insulation protection circuit breaker includes a DC insulation protection module, which is installed on one side of the wiring terminal of the circuit breaker body.

[0007] Preferably, the DC insulation protection module is detachably connected to the circuit breaker body.

[0008] Preferably, the DC insulation protection module includes: a housing, a connecting plate installed inside the housing and connected to the terminals of the circuit breaker body, a first circuit board, and a Hall effect transformer; the Hall effect transformer is connected to the first circuit board; and the Hall effect transformer is sleeved on the connecting plate.

[0009] Preferably, the connecting plate includes a first positive connecting plate and a first negative connecting plate, and the Hall current transformer is simultaneously sleeved on the first positive connecting plate and the first negative connecting plate.

[0010] Preferably, the first circuit board is provided with a current difference detection, alarm, and communication interface in the first DC circuit.

[0011] Preferably, the first circuit board is provided with a first DIP switch.

[0012] Preferably, the Hall effect transformer is located below the first circuit board.

[0013] Preferably, insulating tape is wrapped around the surfaces of both the first positive electrode connecting plate and the first negative electrode connecting plate.

[0014] Compared with the prior art, the beneficial effects achieved by this application are: 1. The insulation detection module is integrated with the circuit breaker, making disassembly and maintenance simple; 2. The insulation detection module includes detection, alarm, communication, and fault protection functions; 3. Insulation detection alarm and fault protection functions are adjustable; 4. The central control box enables unified control of data across the entire circuit (main circuit and all branch circuits). Attached Figure Description

[0015] The accompanying drawings are provided to further illustrate the present application and form part of the specification. They are used together with the embodiments of the present application to explain the application and do not constitute a limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the DC insulation detection circuit breaker structure according to an embodiment of this application; Figure 2 This is a schematic diagram of the insulation detection module according to an embodiment of this application; Figure 3 This is a schematic diagram of the standalone structure of a circuit breaker without an insulation detection module, according to an embodiment of this application. Figure 4 This is a schematic diagram of an insulation detection module without a faceplate according to an embodiment of this application; Figure 5 This is a schematic diagram of the insulation detection module without a circuit board according to an embodiment of this application; Figure 6 This is a schematic diagram of the central control box according to an embodiment of this application; Figure 7 This is a schematic diagram of the internal structure of the central control box according to an embodiment of this application; Figure 8 This is a block diagram illustrating the insulation detection principle of the central control box according to an embodiment of this application; In the diagram: circuit breaker body 1, shunt trip 11, DC insulation protection module 2, first circuit board 21, first Hall current transformer 22, first positive terminal connection board 231, first negative terminal connection board 232, first DC circuit current difference detection, alarm and communication interface 24, first DIP switch 25, central control box 5, third circuit board 51, third DIP switch 52, indicator light 53. Detailed Implementation

[0016] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0017] In the description of this application, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the position or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0018] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0019] like Figures 1-8 As shown: Example 1 This application integrates a DC circuit breaker and a DC insulation protection module into a single switch via a connecting plate. The DC insulation protection module includes a first circuit board, a first Hall effect current transformer, a first positive connection plate, and a first negative connection plate. The first circuit board and the first Hall effect current transformer provide current difference detection, alarm functions, and a communication interface for uploading relevant data in the DC circuit. The shunt trip unit within the DC circuit breaker performs fault disconnection. Simultaneously, the judgment values ​​for alarm and fault protection functions can be adjusted as needed via a first DIP switch.

[0020] In this embodiment, since the insulation fault needs to be detected, the Hall current transformer adopts a toroidal magnetic core structure, and the positive and negative power supply buses of the DC system (corresponding to the first positive connection plate and the first negative connection plate) pass through this magnetic ring at the same time.

[0021] The specific working principle is as follows: Normal operating condition - magnetic field cancellation Under ideal, well-insulated conditions, according to Kirchhoff's current law, the current I+ flowing through the positive busbar is equal to the current I- flowing through the negative busbar, and they are in opposite directions.

[0022] When two wires of equal magnitude but opposite direction pass through the same magnetic ring, their magnetic fields cancel each other out. The total magnetic flux through the ring is zero.

[0023] At this point, the Hall element installed in the air gap of the magnetic ring cannot detect any change in the magnetic field, and the sensor output is zero (or a very small reference value). The system determines that the insulation is normal.

[0024] Insulation fault condition - magnetic field imbalance When an insulation fault occurs in the system (assuming the insulation between the positive terminal and the ground decreases), a portion of the current I_Leak will flow from the positive terminal through the fault point into the ground, and then return to the power source via the grounding point.

[0025] This disrupts the balance: the current I- flowing back to the negative bus will not be equal to I+, but rather I- = I+ - I_Leak.

[0026] At this point, the positive and negative bus currents passing through the magnetic ring are no longer equal in magnitude. The magnetic fields they produce cannot completely cancel each other out, resulting in a net magnetic flux in the magnetic ring that is proportional to the leakage current I_Leak.

[0027] Hall effect detection and output The Hall element in the air gap of the magnetic ring senses this net magnetic flux (magnetic field strength).

[0028] According to the Hall effect, a Hall element will generate a voltage signal (in the mV range) that is proportional to the magnetic field strength.

[0029] The electronic circuitry inside the sensor amplifies and conditions this weak Hall voltage, ultimately outputting a standard signal (such as 0-5V voltage, 4-20mA current, or a digital signal).

[0030] Example 2 The DC insulation detection circuit breaker has functions such as current difference detection, alarm, and fault execution in the first DC circuit. It uploads relevant data to the central control box through the communication interface of Embodiment 1. The central control box makes a judgment based on the judgment value set by the third DIP switch through the data received by the circuit board. At the same time, the indicator lights on the central control box panel display the main circuit and each branch circuit operation, alarm, fault and other signals. If the detection data reaches or exceeds the judgment value set by the third DIP switch, the circuit breaker performs a fault disconnection action.

[0031] The judgment value of the central control box can be adjusted as needed via the third DIP switch.

[0032] The central control box makes judgments based on the data uploaded from the main circuit and each branch circuit, and issues alarms or fault signals to problematic branches. The DC insulation protection circuit breaker executes the fault disconnect command transmitted from the central control box.

[0033] The specific working principle is as follows: For DC ungrounded (IT) systems, the central control box can have the following functions: 1. A single central control box can perform insulation impedance detection on the DC bus; 2. When there are multiple branches, the central control box, in conjunction with the branch molded case circuit breaker, can use the branch leakage current method to detect the branch insulation impedance.

[0034] Insulation testing principle block diagram: as follows Figure 8 As shown.

[0035] Multi-branch insulation testing principle: The central control box can manage, monitor the status of, and calculate the insulation resistance of the branch circuits. Based on the insulation resistance threshold set by the DIP switch of the central control box, it can control the branch circuits to perform protective actions.

[0036] The branch circuit is responsible for detecting leakage current and transmitting leakage current data. Based on the insulation resistance value of the branch circuit calculated by the central control box and the set insulation resistance threshold, the central control box notifies the branch circuit to perform a circuit breaker protection action.

[0037] Leakage current value: Taking branch 1 as an example: The leakage current value measured by the leakage current sensor is the difference between the currents flowing through the two power lines, that is, the value of I=Ip-In. The central control box needs to control the switching of resistors to change the positive and negative bus voltage values ​​to ground, obtaining two sets of positive and negative bus voltage values ​​to ground, which are then recorded. Up 1 Un 1 (Voltage sampled when only S1 is closed) and Up 2 Un 2. (Voltages acquired when S1 and S2 are closed), and simultaneously record the leakage current values ​​acquired at the two time points, as follows: I 1 and I 2; Calculation formula: It is necessary to calculate the insulation resistance of the branch to ground, i.e. R kp and R To find the value of kn and solve for the two unknowns, two systems of equations (Equation 1) need to be established. (1) It can be solved R kp and R kn Busbar insulation testing principle: A single central control box can complete busbar insulation testing.

[0038] set up R p and R n These are the insulation resistances of the busbars to ground; the central control box needs to control the switching of resistors to change the positive and negative voltage values ​​of the busbars to ground, obtaining two sets of voltage values ​​for the positive and negative busbars to ground, which are recorded as follows. Up 1 Un 1 (Voltage sampled when only S1 is closed) and Up 2 Un 2 (Voltage sampled when S1 and S2 are closed), based on the principle of voltage division by resistors, the following equation can be obtained: The insulation resistance values ​​of the positive and negative busbars to ground can be calculated from this.

[0039] According to the voltage divider formula for resistors in series, we can obtain equation 2: (2) According to the voltage divider formula for series resistors, we can obtain equation 3: (3) The insulation resistance of the positive and negative poles of the DC system to ground can be obtained by using Equations 2 and 3.

[0040] The innovations of this application are: 1. The insulation detection module is integrated with the circuit breaker, making disassembly and maintenance convenient; 2. It can detect the insulation status of the branch circuit; it has insulation detection, alarm, communication, and fault protection functions; 3. The insulation detection alarm and fault protection functions are adjustable; the central control box realizes unified control of data from each branch circuit.

[0041] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Finally, it should be noted that the above are merely preferred embodiments of this application and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A full-circuit DC insulation protection circuit breaker, characterized in that, include: DC insulation protection circuit breaker and the central control box connected thereto (5); The central control box (5) displays the operation, alarm, and fault signals of the main circuit and each branch circuit; if the detection data reaches or exceeds the set judgment value, the circuit breaker performs a fault disconnection action.

2. The circuit breaker with full-circuit DC insulation protection as described in claim 1, characterized in that, The central control box is equipped with a third circuit board (51), and the third circuit board (51) is equipped with an indicator light (52) and a third DIP switch (53). The indicator light (52) is used to display the operation, alarm, and fault signals of the main circuit and each branch circuit; The third DIP switch (53) is used to set the judgment value.

3. A circuit breaker with full-circuit DC insulation protection as described in any one of claims 1 or 2, characterized in that, The DC insulation protection circuit breaker includes a DC insulation protection module (2), which is installed on one side of the wiring terminal of the circuit breaker body (1).

4. A circuit breaker with full-circuit DC insulation protection as described in claim 3, characterized in that, The DC insulation protection module (2) is detachably connected to the circuit breaker body (1).

5. A circuit breaker with full-circuit DC insulation protection as described in claim 3, characterized in that, The DC insulation protection module (2) includes: a housing, a connecting plate installed inside the housing and connected to the wiring terminals of the circuit breaker body (1), a first circuit board (21), and a Hall transformer; the Hall transformer is connected to the first circuit board (21); the Hall transformer is sleeved on the connecting plate.

6. A circuit breaker with full-circuit DC insulation protection as described in claim 5, characterized in that, The connecting plate includes a first positive connecting plate (231) and a first negative connecting plate (232), and the Hall current transformer (22) is simultaneously sleeved on the first positive connecting plate (231) and the first negative connecting plate (232).

7. A circuit breaker with full-circuit DC insulation protection as described in claim 5, characterized in that, The first circuit board (21) is provided with a current difference detection, alarm and communication interface (24) in the first DC circuit.

8. A circuit breaker with full-circuit DC insulation protection as described in claim 5, characterized in that, The first circuit board (21) is provided with a first DIP switch (25).

9. A circuit breaker with full-circuit DC insulation protection as described in claim 5, characterized in that, Its features are, The Hall effect transformer is located below the first circuit board (21).

10. A circuit breaker with DC insulation protection or overcurrent protection as described in claim 6, characterized in that, Insulating tape is wrapped around the surfaces of the first positive electrode connecting plate (231) and the first negative electrode connecting plate (232).

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