Research On The Harmonic And Reactive Power Compensation Techniques Of Multi-function Integrated Metro Traction Power Supply System

In view of the problems of the waste of regenerative braking energy,low power factor,contact net ice coating under extreme weather conditions,and low utilization rate of new special equipment in the traditional traction power supply system,a multi-function integrated traction power supply system based on medium voltage energy feeding device is proposed,which makes full use of the four quadrant of the equipment.It can run in various working modes,such as inverting,rectifying,reactive power compensation,harmonic compensation and so on.At the same time,it solves the problems of the energy waste of the train regenerative braking,the low power factor of the system,the icing of the catenary and so on.It simplifies the whole power supply system,reduces the cost of construction and operation and maintenance,and improves the safety of power supply.The main work done in this paper is as follows:(1)Analyze and study the technical scheme of the traditional traction power supply system for urban rail transit.The principle of setting up the traction substation,the main wiring mode,the principle of the diode rectifier unit and the current harmonic distribution are introduced.(2)Proposed a multi-function integrated traction power supply system technical solution.This paper introduces the composition scheme of multi-function integrated traction power supply system,and discusses five core functions of regenerative braking energy feedback,traction power supply,contact network intelligent ice melting,harmonic compensation and decentralized reactive power compensation.The main equipment structure principle and control technology of medium voltage energy feeding device are introduced.(3)The harmonic compensation scheme based on medium voltage energy feed device is studied.The feasibility of the harmonic compensation scheme is demonstrated and the control strategy of harmonic compensation is discussed.Aiming at the harmonic problems existing in the current traction power supply system,two harmonic compensation schemes based on medium voltage energy feeding device are proposed.The simulation results show that the medium voltage energy feeding device has good compensation harmonic effect.(4)The decentralized reactive power compensation technology based on medium voltage energy feed device is studied.Aiming at the reactive power distribution law of medium voltage network,a decentralized reactive power compensation strategy based on medium voltage energy feeding device is given,and the application is verified in the actual circuit.The statistical data show that since the medium-voltage energy-feeding device has opened the distributed reactive power compensation function,the monthly average power factor at the main transformer substation has increased from 0.4-0.5 to 0.8-0.9,and a good compensation effect has been achieved.