High-voltage insulation detection circuit based on 1500V energy storage system

Abstract

The utility model provides a high-voltage insulation detection circuit based on a 1500V energy storage system. The first measuring loop is used for measuring the total voltage of a battery power supply; the second measuring loop is used for measuring the voltage of the first sampling resistor to the ground; and the third measuring loop is used for measuring the voltage of the second sampling resistor to the ground, the second measuring loop is connected with a first capacitor in parallel, the third measuring loop is connected with a second capacitor in parallel, and the connection point of the first capacitor and the second capacitor is grounded. The utility model relates to the field of insulation detection circuits.

Description

Technical Field

[0001] This utility model relates to the field of insulation detection circuits, and in particular to a high-voltage insulation detection circuit based on a 1500V energy storage system. Background Technology

[0002] An insulation testing circuit is used to test the insulation performance of electrical equipment or circuits. Its purpose is to determine the insulation resistance value of the equipment or circuit to judge whether the insulation is good, thereby ensuring the safe operation of the electrical system and preventing faults such as leakage and short circuits.

[0003] Currently, in high-voltage products such as new energy and energy storage, the assessment of system safety often uses AC injection for insulation sampling. This method evaluates the insulation status of the system under test by injecting an AC signal of a specific frequency. This method allows for online monitoring without interrupting system operation and is applicable to various types of power grids. However, this method involves complex circuitry, is susceptible to interference, has low accuracy, and is costly. Utility Model Content

[0004] To address the problems existing in the prior art, this utility model proposes a high-voltage insulation detection circuit based on a 1500V energy storage system that is highly accurate, low-cost, and highly safe.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a high-voltage insulation detection circuit based on a 1500V energy storage system, comprising a battery power supply, a first sampling resistor, a second sampling resistor, a first bridge arm resistor, a second bridge arm resistor, a first switch, a second switch, a third switch, a first capacitor, and a second capacitor; the first bridge arm resistor, the first switch, the first sampling resistor, the second sampling resistor, the second switch, and the second bridge arm resistor are connected in series and then connected across the positive and negative terminals of the battery power supply to form a first measurement circuit for measuring the total voltage of the battery power supply; the first bridge arm resistor, the first switch, the first sampling resistor, and the third switch are connected in series and then connected across the positive and negative terminals of the battery power supply to form a second measurement circuit for collecting the voltage of the first sampling resistor to ground; the second bridge arm resistor, the second switch, the second sampling resistor, and the third switch are connected in series and then connected across the positive and negative terminals of the battery power supply to form a third measurement circuit for collecting the voltage of the second sampling resistor to ground; the first capacitor and the second capacitor are connected in series and then connected across the positive and negative terminals of the battery power supply, and the connection point of the first capacitor and the second capacitor and one end of the third switch share a common ground.

[0006] Based on the above, this utility model can obtain the total battery power supply voltage U, the voltage U1 of the first sampling resistor to ground, and the voltage U2 of the second sampling resistor to ground through the first measurement circuit, the second measurement circuit, and the third measurement circuit, respectively. It has the advantages of simple circuitry, convenient measurement, accurate data, and low implementation cost. The first and second bridge arm resistors in the circuit divide the voltage of the first and second sampling resistors, respectively, reducing the voltage of the sampling system, minimizing interference from high-voltage environments, improving sampling accuracy, and enhancing safety. The first and second capacitors can change the total capacitance value in the circuit, and the charging and discharging process of the capacitors can be controlled through a soft-start unit and a discharge unit, ensuring the safety and stability of the circuit.

[0007] Furthermore, a main positive relay is connected between the positive terminal of the battery power supply and the first capacitor, and a main negative relay is connected between the negative terminal of the battery power supply and the second capacitor.

[0008] Based on the above, the main positive relay and the main negative relay serve as control switches for the system's external connections. When the main positive relay is closed, the positive circuit is connected to the detection section, allowing for the detection of parameters such as the insulation resistance from the main positive relay to ground. If the main positive relay is open, it can, under specific detection requirements, block the electrical connection between the positive circuit and other components, enabling more accurate insulation testing or fault diagnosis. Similarly, when the main negative relay is closed, the negative circuit is connected to the detection loop, facilitating the measurement of insulation performance data from the main negative relay to ground. When the main negative relay is open or closed, it prevents unnecessary interference from the negative circuit to the detection process, ensuring the safety and accuracy of the entire system.

[0009] To more clearly illustrate the above-mentioned features of this utility model and the objectives it aims to achieve, the present utility model will be further described below in conjunction with the accompanying drawings and specific embodiments. Attached Figure Description

[0010] Figure 1 : This is a schematic diagram of the present invention. Detailed Implementation

[0011] like Figure 1 As shown, a high-voltage insulation detection circuit based on a 1500V energy storage system includes a battery power supply BAT, a first sampling resistor Ra, a second sampling resistor Rb, a first bridge arm resistor R1, a second bridge arm resistor R2, a first switch K1, a second switch K2, a third switch K3, a first capacitor C1, and a second capacitor C2.

[0012] The first bridge arm resistor R1, the first switch K1, the first sampling resistor Ra, the second sampling resistor Rb, the second switch K2, and the second bridge arm resistor R2 are connected in series and then connected to the positive and negative terminals of the battery power supply BAT to form a first measurement circuit 1 for measuring the total voltage U of the battery power supply BAT.

[0013] The first bridge arm resistor R1, the first switch K1, the first sampling resistor Ra and the third switch K3 are connected in series and then connected to the positive and negative terminals of the battery power supply BAT to form a second measurement circuit 2 for collecting the voltage U1 of the first sampling resistor Ra to ground;

[0014] The second bridge arm resistor R2, the second switch K2, the second sampling resistor Rb and the third switch K3 are connected in series and then connected to the positive and negative terminals of the battery power supply BAT to form a third measurement circuit 3 for collecting the voltage U2 of the second sampling resistor Rb to ground.

[0015] The first capacitor C1 and the second capacitor C2 are connected in series to the positive and negative terminals of the battery power supply BAT. The connection point of the first capacitor C1 and the second capacitor C2 and one end of the third switch K3 are grounded together.

[0016] A main positive relay K4 is connected between the positive terminal B+ of the battery power supply BAT and the first capacitor C1, and a main negative relay K5 is connected between the negative terminal B- of the battery power supply BAT and the second capacitor C2.

[0017] The specific implementation method of this embodiment is as follows:

[0018] First, close resistors K1 and K2, and sample the voltage across the first sampling resistor Ra and the second sampling resistor Rb. Then calculate the total voltage U of the battery power supply BAT. The formula is:

[0019]

[0020] The total battery voltage U can be obtained using formulas ① and ②.

[0021] Next, close the third switch K3 and the first switch K1, and collect the voltage U1 between the first sampling resistor Ra and ground. Then, close all switches.

[0022] Formula ③ is derived from Kirchhoff's laws:

[0023]

[0024] Then, close the third switch K3 and the second switch K2, and collect the voltage U2 between the second sampling resistor Rb and ground. Close all switches.

[0025] Formula ④ is derived from Kirchhoff's laws:

[0026]

[0027] Finally, by decomposing and substituting formulas ③ and ④, we obtain the two linear equations for the equivalent resistance RX of the positive terminal to ground and the equivalent resistance RY of the negative terminal to ground of the battery power supply BAT:

[0028]

[0029] The resistances of the first bridge arm R1 and the second bridge arm R2 are known. Using the total battery voltage, calculate the equivalent resistances RX and RY of the battery's positive and negative terminals to ground, respectively. When the values ​​of the equivalent resistances Rx and Ry are close to infinity, it indicates good insulation performance of the system. If the values ​​of Rx and Ry are low, it indicates a possible insulation fault in the system. In this case, the system should be stopped for further inspection and handling.

[0030] During the detection process, the resistance value of the bridge arm resistor can be adjusted according to the system voltage to change the voltage of the sampling resistor.

[0031] The above description is only the optimal solution embodiment of this utility model and is not intended to limit this utility model. Various modifications or substitutions made by those skilled in the art to this utility model without departing from the essence and protection scope of this utility model should also be within the protection scope of this utility model.

Claims

1. A high-voltage insulation detection circuit based on a 1500V energy storage system, characterized in that, It includes a battery power supply (BAT), a first sampling resistor (Ra), a second sampling resistor (Rb), a first bridge arm resistor (R1), a second bridge arm resistor (R2), a first switch (K1), a second switch (K2), a third switch (K3), a first capacitor (C1), and a second capacitor (C2). The first bridge arm resistor (R1), the first switch (K1), the first sampling resistor (Ra), the second sampling resistor (Rb), the second switch (K2), and the second bridge arm resistor (R2) are connected in series and then connected to the positive and negative terminals of the battery power supply (BAT) to form a first measurement circuit (1) for measuring the total voltage (U) of the battery power supply (BAT). The first bridge arm resistor (R1), the first switch (K1), the first sampling resistor (Ra) and the third switch (K3) are connected in series and then connected to the positive and negative terminals of the battery power supply (BAT) to form a second measurement circuit (2) for collecting the voltage (U1) of the first sampling resistor (Ra) to ground. The second bridge arm resistor (R2), the second switch (K2), the second sampling resistor (Rb) and the third switch (K3) are connected in series and then connected to the positive and negative terminals of the battery power supply (BAT) to form a third measurement circuit (3) for collecting the voltage (U2) of the second sampling resistor (Rb) to ground. The first capacitor (C1) and the second capacitor (C2) are connected in series to the positive and negative terminals of the battery power supply (BAT). The connection point of the first capacitor (C1) and the second capacitor (C2) and one end of the third switch (K3) are grounded together. A main positive relay (K4) is connected between the positive terminal (B+) of the battery power supply (BAT) and the first capacitor (C1), and a main negative relay (K5) is connected between the negative terminal (B-) of the battery power supply (BAT) and the second capacitor (C2).

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