Energy storage battery management device with insulation detection function

Abstract

The utility model relates to a kind of energy storage battery management device with insulation detection function, belong to energy storage battery technical field, including MCU unit and battery pack monitoring chip, the battery pack monitoring chip is communicated with the MCU unit by SPI communication, the MCU unit is connected with AFE unit by bidirectional daisy chain communication, still including high voltage acquisition circuit, insulation detection circuit and for the DCDC circuit and LDO circuit of the power supply of MCU unit, battery monitoring chip adds the function of high voltage acquisition and insulation monitoring of peripheral circuit.

Description

Technical Field

[0001] This utility model relates to the field of energy storage battery management, and in particular to an energy storage battery management device with insulation detection function. Background Technology

[0002] Currently, energy storage systems can only monitor the insulation resistance between the DC side and the chassis ground in real time when using isolated PCS (Power Control System). However, isolated PCS is expensive, inefficient, and bulky, significantly impacting the power density and cost control of the entire energy storage system. If a non-isolated PCS is used, the energy storage system can only perform an insulation test once during system startup or power-on; real-time insulation testing is not possible during system operation. This means that if an insulation fault occurs during system operation, maintenance personnel directly contacting the DC side and chassis ground are at risk of electric shock. Utility Model Content

[0003] In order to overcome the above-mentioned defects of the prior art, the present invention provides an energy storage battery management device with insulation detection function to solve the problems mentioned in the background art.

[0004] To achieve the above-mentioned utility model objectives, this utility model provides an energy storage battery management device with insulation detection function, including an MCU unit and a battery pack monitoring chip. The battery pack monitoring chip is connected to the MCU unit via SPI communication. The MCU unit is connected to the AFE unit via bidirectional daisy-chain communication. The device also includes a high-voltage acquisition circuit, an insulation detection circuit, a DC-DC circuit for powering the MCU unit, and an LDO circuit. The high-voltage acquisition circuit and the insulation detection circuit are both connected to the battery pack monitoring chip.

[0005] Furthermore, it also includes an SD card circuit, an Ethernet circuit, a current splitter acquisition circuit, and a temperature detection circuit, all of which are connected to the MCU unit.

[0006] Furthermore, it also includes an isolated 485 communication circuit and an isolated CAN communication circuit, both of which are connected to the MCU unit.

[0007] Furthermore, it also includes surge protection circuits and electrostatic discharge (ESD) protection circuits, both of which are connected to the MCU unit.

[0008] Furthermore, the energy storage battery management device uses the insulation detection circuit and algorithm to test the resistance Rx and resistance Ry of the battery's total positive and total negative to the casing ground.

[0009] Furthermore, the resistance R is detected by the circuit. X and the resistor R Y The resistance value, if the resistor R X and the resistor R Y If the resistance value is less than the standard resistance value, the insulation is considered to have failed.

[0010] Compared with the prior art, the beneficial effects of this utility model are: 1. Improve security: Preventing the risk of electric shock: By monitoring the insulation resistance of the energy storage system in real time, potential leakage problems can be detected in time, thereby avoiding the risk of electric shock to operators and maintenance personnel due to contact with live parts; Preventing fire hazards: Insulation faults can lead to short circuits or localized overheating, increasing the risk of fire. Insulation testing can provide early warnings of these problems, helping to take measures to prevent fires. 2. Extend the service life of energy storage systems: Protecting electronic components: Timely detection and handling of insulation defects can prevent damage to the electronic components inside the energy storage system, such as critical components like battery packs and inverters, thereby extending their service life. Reduce maintenance costs: By implementing preventative maintenance, problems can be addressed before they become serious, reducing the need for emergency repairs and lowering long-term maintenance costs; 3. Improve reliability: Reduce downtime: Real-time monitoring allows for repairs before potential problems develop into serious failures, reducing unexpected downtime and production interruptions; Optimize system performance: Good insulation helps maintain the efficient operation of the energy storage system, avoids energy loss due to electrical leakage, and ensures system stability and efficiency; 4. Complies with regulatory requirements Meeting safety standards: Many countries and regions have strict regulations regarding the safety of electrical equipment, including requirements for insulation resistance. Equipping energy storage system manufacturers and users with insulation detection capabilities can help them comply with these regulations and avoid legal risks. Certification support: Having insulation testing capabilities makes it easier for products to obtain the necessary safety certifications, which is crucial for market access. Attached Figure Description

[0011] Figure 1 This is a structural block diagram of an embodiment of the present utility model; Figure 2 This is a schematic diagram of the insulation detection circuit according to an embodiment of the present invention; Figure 3 This is a circuit diagram for collecting Vx during insulation detection in an embodiment of this utility model.

[0012] Figure 4 The flowchart shows the operating system of the unbalanced bridge insulation testing software. Figure 5 Flowchart of the operating system for software to perform insulation testing using the unbalanced bridge method when the energy storage system is stationary. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. The embodiments of this utility model are described below with reference to the accompanying drawings.

[0014] This main control system can perform daily insulation testing on the energy storage system by optimizing the hardware design and software logic when using a non-isolated PCS.

[0015] refer to Figure 1 An energy storage battery management device with insulation detection function includes an MCU unit and a battery pack monitoring chip. The battery pack monitoring chip is connected to the MCU unit via SPI communication. The MCU unit is connected to the AFE unit via bidirectional daisy-chain communication. It also includes a high voltage acquisition circuit, an insulation detection circuit, a DC-DC circuit and an LDO circuit for powering the MCU unit. The high voltage acquisition circuit and the insulation detection circuit are both connected to the battery pack monitoring chip.

[0016] In some embodiments, the system further includes an SD card circuit, an Ethernet circuit, a shunt acquisition circuit, and a temperature detection circuit, all of which are connected to the MCU unit.

[0017] In some embodiments, the system further includes an isolated 485 communication circuit and an isolated CAN communication circuit, both of which are connected to the MCU unit.

[0018] In some embodiments, the system further includes a surge protection circuit and an electrostatic discharge (ESD) protection circuit, both of which are connected to the MCU unit.

[0019] In some embodiments, the insulation detection circuit includes a resistor R X and resistance R Y resistance R X One end is connected to the battery pack, and the resistor R X The other end is connected to the ground wire, and the resistor R Y One end is connected to the battery pack, and the resistor R Y The other end is connected to the ground wire; the resistance R is detected by the circuit. Xand resistance R Y The resistance value, if the resistance R X and resistance R Y If the resistance value is less than the standard resistance value, the insulation is considered to have failed.

[0020] refer to Figure 2 The purpose of insulation monitoring is primarily to detect the resistance between the positive and negative terminals of the battery and the ground. Under normal circumstances, the resistance between the positive and negative terminals and the ground is infinite. However, due to factors such as aging of the insulation or water exposure leading to short circuits, the resistance values ​​of Rx and Ry are detected through the circuit. If these values ​​are found to be less than the standard values, insulation failure is determined. Insulation testing operation strategy: refer to Figure 3 This main control system performs insulation testing in two scenarios based on the unbalanced bridge method. When a non-isolated PCS is connected but in standby mode, a self-developed insulation resistance testing method can be used (insulation resistance test range between 1MΩ and infinity). This method can be performed approximately 2 minutes after the energy storage cabinet has stopped charging or discharging; typically, this test can be performed at least twice a day. When the detected insulation resistance is less than 1MΩ, after disconnecting the main positive and negative relays of the high-voltage box (disconnecting the battery side from the PCS), the unbalanced bridge insulation test is performed using the conventional method. After disconnecting the non-isolated PCS, the accurate insulation resistance value is obtained. Under normal circumstances where insulation is not an issue, only the self-developed insulation testing method needs to be used (without disconnecting the PCS), greatly reducing the impact of insulation testing on the normal operation of the entire energy storage system.

[0021] refer to Figure 4 , Figure 5 The specific implementation details and software control process are as follows: The main control system first obtains the PCS operating status. This can be done by judging the DC-side current value and by communicating with LEMS (Local Energy Management System) via CAN to obtain the charging and discharging strategy for predicting the operating status. Insulation testing is performed when the PCS is in standby mode (without system charging or discharging). Multiple tests can be performed within a single time period, and the overall test values ​​from multiple time periods are analyzed to preliminarily determine the insulation status. 2. Specific implementation method: The main control system tests the battery total voltage VBAT and Vx. The value obtained from Vx / VBAT is used to determine the value through a software lookup table (this table is pre-established using a large amount of test data). If there is an insulation problem, a conventional unbalanced bridge insulation test is performed. In the software, insulation testing is divided into two parts: insulation testing when the energy storage system is in standby mode and insulation testing when the energy storage system is first powered on or re-energized (without PCS connection).

[0022] Compared with the prior art, the advantages of this utility model include: 1. Improve security: Preventing the risk of electric shock: By monitoring the insulation resistance of the energy storage system in real time, potential leakage problems can be detected in time, thereby avoiding the risk of electric shock to operators and maintenance personnel due to contact with live parts; Preventing fire hazards: Insulation faults can lead to short circuits or localized overheating, increasing the risk of fire. Insulation testing can provide early warnings of these problems, helping to take measures to prevent fires. 2. Extend the service life of energy storage systems: Protecting electronic components: Timely detection and handling of insulation defects can prevent damage to the electronic components inside the energy storage system, such as critical components like battery packs and inverters, thereby extending their service life. Reduce maintenance costs: By implementing preventative maintenance, problems can be addressed before they become serious, reducing the need for emergency repairs and lowering long-term maintenance costs; 3. Improve reliability: Reduce downtime: Real-time monitoring allows for repairs before potential problems develop into serious failures, reducing unexpected downtime and production interruptions; Optimize system performance: Good insulation helps maintain the efficient operation of the energy storage system, avoids energy loss due to electrical leakage, and ensures system stability and efficiency; 4. Complies with regulatory requirements Meeting safety standards: Many countries and regions have strict regulations regarding the safety of electrical equipment, including requirements for insulation resistance. Equipping energy storage system manufacturers and users with insulation detection capabilities can help them comply with these regulations and avoid legal risks. Certification support: Having insulation testing capabilities makes it easier for products to obtain the necessary safety certifications, which is crucial for market access.

[0023] The technical solution of this utility model has been described above with reference to specific embodiments. However, it should be noted that the above description is only for explaining the solution of this utility model and should not be construed as a specific limitation on the scope of protection of the utility model in any way. Based on this explanation, other specific embodiments or equivalent substitutions of this utility model that can be conceived by those skilled in the art without creative effort will all fall within the scope of protection of this utility model.

Claims

1. A battery management device with insulation detection function, characterized in that, The device includes an MCU unit and a battery pack monitoring chip. The battery pack monitoring chip is connected to the MCU unit via SPI communication. The MCU unit is connected to the AFE unit via bidirectional daisy-chain communication. The device also includes a high-voltage acquisition circuit, an insulation detection circuit, a DC-DC circuit for powering the MCU unit, and an LDO circuit. The high-voltage acquisition circuit and the insulation detection circuit are both connected to the battery pack monitoring chip.

2. The energy storage battery management device with insulation detection function according to claim 1, characterized in that, It also includes an SD card circuit, an Ethernet circuit, a splitter acquisition circuit, and a temperature detection circuit, all of which are connected to the MCU unit.

3. The energy storage battery management device with insulation detection function according to claim 1, characterized in that, It also includes an isolated 485 communication circuit and an isolated CAN communication circuit, both of which are connected to the MCU unit.

4. The energy storage battery management device with insulation detection function according to claim 1, characterized in that, It also includes a surge protection circuit and an electrostatic discharge (ESD) protection circuit, both of which are connected to the MCU unit.

5. The energy storage battery management device with insulation detection function according to claim 1, characterized in that, The energy storage battery management device uses the insulation detection circuit and algorithm to test the total positive and total negative resistances Rx and Ry of the battery to the casing ground.

6. The energy storage battery management device with insulation detection function according to claim 5, characterized in that, The resistance R is detected by the circuit. X and the resistor R Y The resistance value, if the resistor R X and the resistor R Y If the resistance value is less than the standard resistance value, the insulation is considered to have failed.

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