| All vanadium redox battery (referred to as VRB) is a new type of clean energy storage device, vanadium battery has many advantages such as the power, long service life, high reliability and operation and maintenance costs less, support frequent charge and discharge, etc, considered widly used in supporting energy storage equipment of the solar energy, wind power generation unit, electric vehicle power supply, emergency power supply system, power station storage load, renewable energy combined to the grid, urban power grid storage, remote power supply, UPS system and other areas.This paper first discuss work principle, characteristics, key technologies, as well as VRB application prospect of VRB, and then take a VRB at a substation to experiment object, we develop the monitoring system for VRB based on PLC, in the system operation and maintenance, it has played an important role. It can realize the functions such as:(1) Independent designing power circuit, control module group, power frequency conversion unit group, it can realize the system redundancy;(2) Fault diagnosis and restore function, which can effectively avoid failure of misjudgment, leakage conviction, realize the unattended function;(3) Friendly human-machine interface, operation people can monitor and adjust the relevant parameters through the man-machine interface in order to adapt to the requirements of operation conditions;(4) Display real-time data, plot historical curve, save parameter data, query historical data. The actual operation shows that the system can stably operate, convenient operate, which greatly increased the usability of the VRB.Deu to VRB need to rely on circulating pump power operation, and monitor some key parameters. When the vanadium redox battery in operation process especially in charge and discharge condition will not allow circulating pump stall, then the reliability of vanadium redox battery monitoring system put forward high request. This paper then analysis monitoring system structure of vanadium redox battery before improvement, and using reliability block diagram, fault tree analysis, Blocksim software to monitor system for the reliability analysis, finding out the key points of the system, and improving the key points, contrast reliability index of improvement and before improvement, showing that the reliability of improved monitoring system has obviously improved. System reliability improvement from0.569to0.782, and MTBF have also been extended from17775hours to45539hours.Substation is the really point of transmission and distribution of power in power system, it can transform voltage, accept and distribute electric power, control the flow of power and adjust the voltage of power facilities. Backup protection power as an important part of the DC power supply system, provides the security, stability, load reliable power security for secondary system of power system, ensure the normal operation function of relay protection, communications equipment. Energy storage battery now has developed including lead-acid battery, nickel batteries, lithium battery, fluid flow battery and sodium-sulphur battery types,etc. By comparing the existing energy storage battery technology, visible the applications of vanadium redox battery, comparing the original lead-acid battery backup power and vanadium redox battery, highlight the advantages of vanadium redox battery as the backup power, and elaborate the work principles, system structure, characteristics and operation monitoring of vanadium redox battery. Based on the trial applications of vanadium redox battery in substation, introduce the applications of the system and its charging and discharging mode, charging and discharging conditions, etc... |
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