Device and method for detecting open circuit and health state of backup battery of transformer substation

Abstract

The invention relates to the technical field of transformer substation storage battery detection, in particular to a transformer substation backup battery open circuit and health state detection device and method.The transformer substation backup battery open circuit and health state detection device comprises a main controller which is connected with a voltage detection module, a current detection module, a single body detection module, a convergence module, an alarm module, a voltage reduction module, a wave recording module and a communication module through 485 interfaces; and the alarm module is used for summarizing, analyzing and judging data and controlling to send out alarm signals. Parameters of the storage battery pack and a single battery can be detected at the same time, and the battery state can be evaluated in time. According to the invention, an automatic detection period can be set, and alarm signals can be received in real time.

Description

Technical Field

[0001] The present invention relates to the technical field of substation battery detection, and in particular to a device and method for detecting open circuit and health status of a substation backup battery. Background Art

[0002] Power outages caused by open circuits in batteries or discharge circuits often lead to losses in substations. The open circuit problem has become a pain point for backup battery packs. Currently, open circuit detection of substation backup battery packs mainly relies on manual on-site charge and discharge tests.

[0003] However, this manual testing method has numerous drawbacks: The manual discharge cycle is long, typically only once a year, and the battery status cannot be determined between discharges, leading to untimely testing. Manual discharge is time-consuming and labor-intensive, resulting in high costs and a high workload. Manual discharge disconnects the battery pack from the busbar, making it impossible to detect potential open circuits, such as a loose fuse, a damaged circuit breaker, or a burned-out shunt. While existing online battery testing devices can measure individual battery cell parameters such as voltage, internal resistance, and temperature, internal resistance testing cannot directly determine the health of the battery, nor can it detect open circuits in the battery discharge circuit.

[0004] For example, the invention patent with publication number CN109870660B describes a battery pack open circuit detection system and method. This method uses software to control the charging module voltage boost to measure the battery pack charging current. While this method can determine whether a battery pack has an open circuit fault, the software-controlled module voltage boost has drawbacks. The software needs to be compatible with the communication protocols of all module manufacturers. However, in actual use, each manufacturer's communication protocols are different and are subject to irregular upgrades, making full compatibility almost impossible. If only compatible with its own charging modules, large-scale installation is impossible, greatly limiting its scope of application.

[0005] Based on this, the present invention designs a device and method for detecting open circuit and health status of backup batteries in substations to solve the above problems. Summary of the Invention

[0006] The purpose of the present invention is to provide a device and method for detecting open circuit and health status of backup batteries in substations, so as to solve the problems in the prior art of untimely detection, inability to detect hidden dangers of open circuit in discharge circuits, and indirect detection results.

[0007] To solve the above technical problems, the present invention is achieved through the following technical solutions: A substation backup battery open circuit and health status detection device, comprising: The main controller is connected to the voltage detection module, current detection module, single detection module, convergence module, alarm module, voltage reduction module, wave recording module, and communication module through the 485 interface, and is used to summarize, analyze, and judge data and control the issuance of alarm signals; The voltage detection module, including voltmeters V1 and V2, is used to detect the voltage of the DC system's charging module and load bus, respectively, collect voltage signals, and send them to the main controller. The DC system's charging module refers to the AC / DC module. The charging module and the battery are in parallel. It can be understood that the power of the charging module is first output to the DC bus and then to the battery. In this way, once the DC module loses power, the battery can immediately carry the load; The current detection module includes a Hall sensor, which is used to collect the current signal of the battery and send it to the main controller; Single cell detection module detects the voltage, internal resistance, temperature, and capacity data of a single battery and communicates with the convergence module via the Modbus protocol; The convergence module aggregates and compiles the data from the individual detection modules and sends it to the main controller; Alarm module, including sound and light alarm device; The step-down module reduces the module output voltage to below the battery pack voltage, allowing the battery to carry the load; The waveform recording module samples the voltage and current signal data at the millisecond level to generate continuous measurement points, which are then connected to form a monitoring curve. The communication module converts the data collected by the main controller into the IEC61850 or IEC104 protocol required by the user and uploads it to the substation's station-based monitoring system.

[0008] Furthermore, the step-down module includes: The step-down silicon chain is connected in series between the charging module and the load bus of the DC system to reduce the output voltage of the step-down module to below the battery pack voltage. In the detection state, the lower port voltage of the output end, i.e. V2, is lower than the battery pack voltage. The battery pack serves as a power source to supply power to the load. The step-down silicon chain is connected in series with the charging module and the load bus, and in parallel with the two contactors. In the standby state, it draws power from the load bus.

[0009] The contactors, including the normally closed DC contactor 1K1 and the normally closed DC contactor 1K2, are connected in parallel at both ends of the step-down silicon chain, and the switching of the step-down silicon chain is determined by opening and closing. In order to better achieve the technical effect, the present invention provides a method for detecting the open circuit and health status of a backup battery in a substation, including two working states: Standby state: the contactor is closed, the step-down silicon chain is short-circuited, the voltage detection module detects the voltage across the contactor in real time, the charging module charges the measured battery, and the current detection module detects the charging current of the measured battery in real time; Detection status: the contactor is disconnected, the step-down silicon chain is put into circuit, the voltage detection module detects the voltage at both ends of the step-down silicon chain in real time, the measured battery is discharged, and the current monitoring module detects the discharge current of the measured battery in real time.

[0010] The detection steps are as follows: S1, the contactor is closed, the detection device is in standby mode, the voltage detection module and the current detection module perform real-time detection, and the detection results are uploaded to the main controller; S2, when the current module is lower than the set value, the main controller sends a command to start the detection state; S3, detection status detection, the contactor is disconnected, the voltage detection module and the current detection module perform real-time detection, and the detection results are uploaded to the main controller; S4, when the detected value does not meet the set value, the main controller sends a command to close the contactor, the alarm module sends an alarm, and the detection ends; when the detected value meets the set value, the main controller sends a command, the detection ends, and the device returns to the standby state.

[0011] Furthermore, in S1, the voltage detection module detection steps are specifically as follows: S11, voltmeter V1 detects the charging module voltage in real time. When the main controller determines that it is lower than the set value, the alarm module will sound an alarm; S12, voltmeter V2 detects the load bus voltage in real time. When the main controller determines that it is lower than the set value, the alarm module will sound an alarm; S13, the main controller determines the pressure difference between V1 and V2. When the main controller determines that the pressure difference is greater than the set value, the alarm module sounds an alarm.

[0012] Furthermore, S3 is specifically: S31, the Hall sensor detects the battery current in real time. When the main controller determines that the current is lower than the set value, the alarm module will sound an alarm; S32, voltmeter V2 detects the battery voltage in real time. When the main controller determines that the battery voltage is lower than the set value, the alarm module will sound an alarm; S33, the main controller determines the V1-V2 pressure difference. If the main controller determines that the pressure difference is not within the set value range, the alarm module will sound an alarm.

[0013] The present invention has the following beneficial effects: The present invention can simultaneously detect the parameters of a battery pack and a single battery, and can timely evaluate the battery status. The present invention can set an automatic detection cycle and receive alarm signals in real time. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0015] Figure 1 Schematic diagram of the hardware structure of the detection device of the present invention; Figure 2 This is the schematic diagram of the buck module circuit; Figure 3 Logic diagram of the detection method of the present invention; Figure 4 2 is a system architecture diagram of the detection device of the present invention. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. It should be understood that the terms "upper", "middle", "outer", "inner", "lower" and the like indicating directions or positional relationships are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the components or elements referred to must have a specific direction, and therefore should not be understood as limiting the present invention.

[0017] Under normal conditions, the single-cell detection module detects the voltage, internal resistance, temperature and capacity data of a single battery in real time. The convergence module summarizes and compiles the data from the single-cell detection module and sends it to the main controller.

[0018] In standby mode: The contactor is closed. Voltmeter V1 monitors the voltage of the DC system's charging module, or AC / DC module, in real time. Voltmeter V2 monitors the load bus voltage in real time and transmits the collected voltage signal to the main controller, which simultaneously monitors the voltage differential between the module and load bus voltages. Set values ​​are set for the module voltage and the load bus voltage. When they fall below the set values, the main controller issues a load bus voltage loss alarm. A set value is set for the voltage differential between voltmeters V1 and V2. When the main controller detects a voltage differential greater than the set value, it issues a contactor trip alarm. Simultaneously, the waveform recording module records the load bus voltage measured by voltmeter V2 every second, generating a waveform recording curve. If the load bus voltage fluctuates by more than ±2V, the fault waveform from one minute before the fluctuation until the voltage returns to normal is automatically saved and uploaded to the substation's backend monitoring system via the communication module.

[0019] The Hall sensor detects the battery current in real time and uploads it to the main controller to set the battery current set value. When the charging current is greater than the set value, the main controller determines that the measured battery is in the equalization charge state and prohibits starting the detection state.

[0020] The judgment of the equalization charge state is set according to the battery capacity of the measured battery, usually set to 0.01 times the battery capacity. For example, the float charge current of a 100AH ​​battery is 0.01*100=1A.

[0021] The steps for detecting the status are as follows: The main controller controls the disconnection of contactor 1k1 and contactor 1k2, and the waveform recording module continuously collects the voltage of the V2 voltage module for 1 second and generates a waveform recording curve until the detection is completed.

[0022] 2. The current detection module detects the battery current in real time. The current module is connected to the main controller through the 485 interface. When the main controller determines that the battery current is lower than the set value, the contactor is closed and the standby state is restored. The main controller issues an alarm that there is a hidden danger of open circuit in the battery. The alarm light of the alarm module lights up and the buzzer sounds. The alarm signal is uploaded to the substation background monitoring system.

[0023] 3. Voltmeter V2 detects the battery voltage. When the main controller determines that the battery voltage is lower than the set value, it closes the contactor and returns to the standby state. If it detects that the voltage drops by more than 20V within 5 minutes, the main controller issues an alarm that the measured battery voltage drops too fast. 4. Detect the voltages of voltmeter V1 and voltmeter V2 in real time and calculate the voltage difference. When the main controller determines that the voltage difference is higher than the highest value or lower than the lowest value of the set value range, it closes the contactor and returns to the standby state. If the voltage difference is less than 2V, the main controller issues an alarm that the step-down silicon chain cannot step down the voltage; if the voltage difference is greater than 30V, the main controller issues an alarm that the step-down silicon chain is broken.

[0024] 5. If none of the above conditions are triggered, the battery is deemed healthy and the test ends.

[0025] When the main controller issues an alarm command, the display will show the alarm reason, and the sound and light alarm device will sound an alarm. The signal is sent to the substation background monitoring system through 104 or 61850.

[0026] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all details in detail, nor do they limit the present invention to specific implementation methods.

Claims

1. A device for detecting open circuit and health status of backup batteries in substations, characterized by: include, The main controller is connected to the voltage detection module, current detection module, single detection module, convergence module, alarm module, voltage reduction module, wave recording module, and communication module through the 485 interface, and is used to summarize, analyze, and judge data and control the issuance of alarm signals; The voltage detection module includes voltmeters V1 and V2, which are used to detect the voltage of the charging module and load bus of the DC system respectively, collect voltage signals, and send them to the main controller; The current detection module includes a Hall sensor, which is used to collect the current signal of the battery and send it to the main controller; Single cell detection module detects the voltage, internal resistance, temperature, and capacity data of a single battery and communicates with the convergence module via the Modbus protocol; The convergence module aggregates and compiles the data from the individual detection modules and sends it to the main controller; Alarm module, including sound and light alarm device; The step-down module reduces the module output voltage to below the battery pack voltage, allowing the battery to carry the load; The waveform recording module samples the voltage and current signal data at the millisecond level to generate continuous measurement points, which are then connected to form a monitoring curve. The communication module converts the data collected by the main controller into the IEC61850 or IEC104 protocol required by the user and uploads it to the substation's station-based monitoring system.

2. The substation backup battery open circuit and health status detection device according to claim 1, characterized in that: The step-down module includes: The step-down silicon chain is connected in series between the charging module and the load bus of the DC system to reduce the output voltage of the step-down module to below the voltage of the battery pack, allowing the battery to carry the load; The contactors, including the normally closed DC contactor 1K1 and the normally closed DC contactor 1K2, are connected in parallel at both ends of the step-down silicon chain, and the switching on and off of the step-down silicon chain is determined by opening and closing.

3. A method for detecting open circuit and health status of backup batteries in a substation, characterized by: There are two working states: Standby state: the contactor is closed, the step-down silicon chain is short-circuited, the voltage detection module detects the voltage across the contactor in real time, the charging module charges the measured battery, and the current detection module detects the charging current of the measured battery in real time; Detection status: the contactor is disconnected, the step-down silicon chain is put into circuit, the voltage detection module detects the voltage at both ends of the step-down silicon chain in real time, the measured battery is discharged, and the current monitoring module detects the discharge current of the measured battery in real time.

4. The method for detecting open circuit and health status of backup batteries in substations according to claim 3, characterized in that: S1, the contactor is closed, the detection device is in standby mode, the voltage detection module and the current detection module perform real-time detection, and the detection results are uploaded to the main controller; S2, when the current module is lower than the set value, the main controller sends a command to start the detection state; S3, detection status detection, the contactor is disconnected, the voltage detection module and the current detection module perform real-time detection, and the detection results are uploaded to the main controller; S4, when the detected value does not meet the set value, the main controller sends a command to close the contactor, the alarm module sends an alarm, and the detection ends; when the detected value meets the set value, the main controller sends a command, the detection ends, and the device returns to the standby state.

5. The method for detecting open circuit and health status of backup batteries in substations according to claim 4, characterized in that: In S1, the voltage detection module detection logic is as follows: S11, voltmeter V1 detects the charging module voltage in real time. When the main controller determines that it is lower than the set value, the alarm module will sound an alarm; S12, voltmeter V2 detects the load bus voltage in real time. When the main controller determines that it is lower than the set value, the alarm module will sound an alarm; S13, the main controller determines the pressure difference between V1 and V2. When the main controller determines that the pressure difference is greater than the set value, the alarm module sounds an alarm.

6. The method for detecting open circuit and health status of backup batteries in a substation according to claim 4, characterized in that: In S3, the detection logic of the voltage detection module and the current detection module are as follows: S31, the Hall sensor detects the battery current in real time. When the main controller determines that the current is lower than the set value, the alarm module will sound an alarm; S32, voltmeter V2 detects the battery voltage in real time. When the main controller determines that the battery voltage is lower than the set value, the alarm module will sound an alarm; S33, the main controller determines the V1-V2 pressure difference. When the main controller determines that the V1-V2 pressure difference is not within the set value range, the alarm module issues an alarm.

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