Power Quality Comprehensive Treatment Of Coal Power System Based On The STATCOM Technology

Power is the main source of power in the process of coal production. The safety andreliability of the electricity system related to the stable operation of production efficiencyand equipment of coal enterprise, and even related to every coal mine worker’s personalsafety. The mine’s main electrical equipment SCR-D has the lower power factor (usually0.02~0.8), serious harmonic pollution, but also the start of idle impact, cause voltagefluctuation. Research on the comprehensive control scheme for electric energy quality ofpower system, is not only the demand of saving energy and reducing consumption, andproduction safety.The power quality management of above power system with lots ofimpact resistance, nonlinear and harmonic serious load requires reactive powercompensation technology with fast tracking compensation ability. The STATCOM ismainly using high-power power electronic switching device consists of a voltage sourceinverter, through the dynamic change of output voltage amplitude and phase toimplement and system reactive power exchange. This system has the properties of quickadjusting speed, low power consumption and small volume. It is an ideal choice forpower system of power quality comprehensive management for coal mine etc.The features of electricity system in coal mine and the power quality problemsgenerated by SCR-D are analyzed. The basic principle of the chain STATCOMtechnology is studied, the advantages and disadvantages of the diode clamp,flying-capacitor clamp and chain H bridge cells cascade multilevel inverter topologystructure are analyzed. The STATCOM device of the subject uses the chain H bridge cellscascade multilevel inverter topology. The current control strategy based on passivity andBoost power converter of the chain STATCOM has the good properties of dynamicsteady state and strong robustness. The power quality comprehensive treatment strategyof coal power system based on the STATCOM technology is designed. And it is appliedto a coal mine substation. The results show that the total distortion rate of voltage isdecreased from10～11%to2～3%, and the power factor increased to0.94～0.99fromprimary0.62～0.75, and the compensation effect is obvious.