The Design And Implementation Of On-Line Monitoring System Of The Storage Battery In Substation

VRLA battery is often used as back-up power in the power supply system. It is a DC power supply and when the main power supply system fails, the secondary power system maintains its normal operating system powered by batteries. Therefore the stability of VRLA battery and the actual capacity, providing for the load in the discharge process, has a highly significance in making sure that electrical equipment work regularly. In most cases, battery management detect the capacity of batteries by a discharge test, or by replacing batteries periodically in substation, in order to protect electric equipment from appearing faults due to lacking of capacity. But a discharge test will spend much time and replacing batteries results a waste of batteries and economic losses. To solve these problems, the paper designs and completes a real-time online system to monitor the status of batteries.The system consists of data acquisition unit, SBUS conversion unit, the primary controller unit and monitoring host unit, with using sensor technology, computer technology and modern communication technology comprehensively. Battery sensors and current sensors are used to detect batteries operating parameters real-time by battery acquisition unit. The SBUS serial bus communication protocol has been used in battery sensors, and the sensors connected together via communication lines with SBUS converters. The reliable of data transmission will be ensured with the redundancy of SBUS effectively. The system uses a SBUS conversion unit, which can change the battery parameter signal to the serial data stream, which can be received directly by the primary controller. The primary controller unit receives the battery parameters and processes them, then display then on the LCD display. Meantime, the primary controller transmits battery parameters to the monitoring host through GPRS wireless communication, and the controller compares battery parameters with the pre-set battery parameter thresholds. If it has been detected that the detecting battery parameters exceed the pre-set battery parameter thresholds, the controller will drive the buzzer to give a warning. Monitoring host receives battery data, uploading from the controller, stores data and displays the working status of the battery. Through an algorithm, the system can calculate the residual capacity and the deterioration degree of batteries. Monitoring host provides abnormal alarm function when battery parameters are abnormal, historical data query functions and reports generating functions. The real-time status of batteries is displayed intuitively on the monitoring interface. With this method, it provides battery management and maintenance personnel in substation management with convenience, and reduces economic losses. Compared with the traditional battery management methods, this system can detect the battery operation state automate and reduce the workload of the substation management, achieve the purpose that when some batteries appear faults, the maintenance personnel can find and dispose the faults, or replace the faulted batteries. It reduces the security risk of the breakdown DC power system, which is due to the battery failure, and it provides some reference for the development of intelligent substations.