Research On Treatment Method Of Electrified Railway Power Quality

Electrified railway is of great significance to the development of the national economy and social progress. However, the characteristics of the electric locomotive load nonlinear, asymmetric, impact-resistance triggered power quality problems such as harmonics, negative sequence current, voltage fluctuations and flicker. It reduces power supply quality of the electric power system and affects the safety and economic operation of the power system. Therefore, we must take effective compensation measures for the comprehensive management of electrified railway power quality. Power quality problems exist in the existing traditional electrified railway and vigorously develop high-speed rail are discussed, and corresponding control measures are proposed. The simulation results confirm the effectiveness of the proposed method.In this paper, treatment method of electrified railway power quality is studied. The main work is presented as follows:Considering problems such as traditional electrified railway load harmonics, reactive, and the grid side voltage fluctuations, harmonics, power quality compensation device unified power quality regulator (UPQC) are studied. We learn topological structure and principle of the compensation device, including the series compensation unit and the parallel compensation unit. Power quality detection methods and control strategies for UPQC are studied. The paper analyzes the optimal steady-state power of UPQC, and energy optimization compensation strategy is proposed. Simulations confirm that the UPQC optimize compensation requires less energy than full compensation, and can reduce the capacity of the compensating device, which improve the economy of the device.Considering problems such as harmonic current and negative sequence current of high-speed railway traction supply system, an optimal compensation strategy for energy based on railway static power conditioner (RPC) is proposed. In the condition of optimum compensation, compensation detecting method of harmonic current and negative sequence current is discussed. The paper analyzes the optimal steady-state power of RPC and Three performance-indexes are also proposed for compensation energy of RPC, which are the active power compensation degree y and reactive power compensation angle φ, harmonic current compensation degree ψ.Particle swarm optimization (PSO)is used to calculate the active power compensation degree γ, reactive power compensation angle φ, and harmonic current compensation degree y/, by which the optimal energy control of RPC is realized. The capacity of RPC is set by the optimal compensation strategy for energy. An engineering application method is proposed for real time compensation. Simulations confirm that the RPC compensation capacity is reduced under the optimal control strategy for energy proposed in this paper, which greatly improves the economy of the device.