In the absence of AC power supply for hydropower plants, the electrical energy stored in the DC system battery and the hydraulic energy stored in the pressure tank of the oil pressure device can complete the unit start-up. Therefore, monitoring the operation status of the battery is crucial. This article briefly describes the renovation plan and practice of the online monitoring system for a hydroelectric power plant's battery, providing ideas and methods for domestic peers facing similar problems.

Keywords: Battery online monitoring system; renovation

1 Introduction

The production area of a certain hydropower plant is equipped with four sets of 220V battery online monitoring systems, namely the first and second sets, switch station and dam 220V battery online monitoring systems (each set of 220V battery online monitoring system monitors two sets of 220V batteries). As the monitoring module of the 220V battery online monitoring system has reached its service life and has been discontinued, it is planned to renovate the 220V battery online monitoring system. The main task of this assignment is to remove the original 4 sets of 220V battery online monitoring system cabinets and their affiliated equipment, install the newly purchased 4 sets of 220V battery online monitoring system cabinets and their affiliated equipment, and complete the debugging and experimentation of the new 220V battery online monitoring system.

Introduction to the Online Monitoring System for Batteries

The manufacturer of the new device battery online monitoring device is Fuzhou Fuguang. The monitoring device can obtain real-time data such as individual cell voltage, total voltage of the battery pack, discharge current, etc. (with one key capacity verification function). This monitoring system has a battery outlet switch, which does not require disconnecting the battery outlet wiring when the battery is charged. It has real-time and continuous collection, storage, calculation, analysis, and control of data and operating status information such as battery voltage, current, internal resistance, temperature, etc. Through abnormal alarm, capacity verification (setting), long-distance communication and other functions, it completes online monitoring, maintenance and trend analysis management of battery status, and has intelligent alarm, information induction and analysis, self diagnosis long-distance maintenance and other functions. The alarm function can be set on and off as needed.

3 Renovation Plan

3.1 Plan Overview

The renovation of the 220V battery online monitoring system this time is divided into four parts: the removal of the old cabinet and its affiliated equipment (single collection line), the wiring of the new cabinet and its affiliated equipment (single collection line, single monitoring module, fast access device for nuclear capacity), the power on debugging of the new cabinet, and the nuclear capacity experiment of the battery pack.

3.2 Removal of old cabinets and installation of new cabinets

Remove the fixing bolts and grounding points of the old cabinet, and move the old battery online monitoring system cabinet away. Conduct a new cabinet inspection, and the appearance of the cabinet should be free of damage and deformation, the paint should be intact and undamaged, and the internal components of the cabinet should be undamaged. After removing the bottom wheel of the new cabinet, the cabinet device should be installed horizontally and vertically, with a horizontal allowable deviation of less than 1mm/meter and a vertical allowable deviation of less than 1mm/meter. After the adjustment of the cabinet is completed, it should be fixed by an electric welder and the cabinet should be well grounded.

3.3 Device battery pack unit collection module, transition plate and its bracket, etc.

The orientation of the battery pack aggregation module is fixed with double ears and fixed on the battery rack. Open gaskets and battery wires are used to connect the battery cell module to the battery. The red wire is connected to the positive pole of the battery, and the black wire is connected to the negative pole of the battery. As shown in Figure 1:

Figure 1 Single collection cable

After connecting the complete set of unit wires, connect the unit module to the white terminal of the test wire and ensure it is secure. Use 3M adhesive on the back of the module to fix it, and the module can be fixed on the battery pack bracket.

The communication connection between the individual modules and the battery pack aggregation module ensures a sturdy and reliable connection. Communication network cables are installed between the individual battery modules.

Connect a measuring wire from the positive (or negative) pole of battery # 1 and the negative (or positive) pole of battery # 103 respectively to the aggregation module for measuring the total voltage of the battery pack; Install a current transformer on the charging and discharging cable at one end of the battery pack, and connect the measured current to the aggregation module through the measurement wiring for measuring the battery pack current.

The battery pack aggregation module and display module are connected through 485 communication, and the 485 interface of the battery pack aggregation module is a standard T568B network cable interface. The brown wire of the network cable is the positive pole, and the brown white wire is the negative pole, which is docked with the display module 485. The transition plate is mainly used for battery capacity wiring.

First, install the battery core capacity cable at the cabinet end, then install the core capacity cable at the 220V # 1 battery pack end, and check that the insulation of the core capacity cable is good according to the insulation inspection record table. Close K1, check the operation status of the equipment inside the cabinet, and confirm that there is no short circuit or grounding.

3.4 New Battery Online Monitoring System Power on Debugging

After powering on, use a multimeter to measure the power supply voltage of the cabinet, check that the cabinet is running normally, check that all components are running normally, and check that the monitoring data of the battery pack shows normal operation. After powering on, verify and acknowledge the parameters of the battery online monitoring system, and complete the logic verification of the battery alarm according to the signal verification record table.

3.5 Core capacity of battery pack

Perform balanced charging of 220V # 1 battery pack. Disconnect the 220V # 1 battery pack, connect the battery pack capacity verification device, perform the 220V # 1 battery pack capacity verification, and record the capacity data. Perform balanced charging of 220V # 2 battery pack. Disconnect the 220V # 2 battery pack, connect the battery pack capacity verification device, perform the 220V # 2 battery pack capacity verification, and record the capacity data.

4. Effect after renovation

After investigation, the battery online monitoring system has monitoring functions (voltage, current, internal resistance, temperature, battery operation status, etc.), various levels of operation permissions and password protection functions, active inspection functions (inspection cycle not exceeding 5 seconds), power-off protection function, real-time communication function, event recording and storage function, host alarm function, intelligent alarm, information induction and analysis, self diagnosis long-distance maintenance function, manual active measurement of battery internal resistance and connecting strip resistance, measurement cycle can be set, battery pack capacity display and function value target evaluation function, analysis diagnosis and alarm reminder function, parameter setting function (monitoring time distance, alarm temperature, alarm voltage, etc.), local display and recording function, with supporting data processing software, can generate curves and reports Digital display and bar chart display functions (individual resistance, voltage). The online monitoring system for batteries has a dazzling display of the highest and lowest values, actively switches to the alarm screen in case of abnormalities, and has specific alarm records and verification discharge experiment functions. The entire process of experimental discharge is recorded, and an experimental report is actively generated. The discharge is stopped by actively blocking the artificial discharge load, and an audible and visual alarm and stop signal are issued. In non float charging conditions, the internal resistance test results should be exited normally.