Research On Negative-sequence And Reactive Compensation In Electric Railway Based On Sequence Impedance

The development of our country's electric railway is rapid, the electrification railroad's negative sequence and the overtone question is following, because the electrification railroad's hauling load is large capacity single-phase rectification load, the movement will take big negative sequence and harmonic component. The solution of overtone question is relatively mature, the use of active and passive filter is common. But the negative sequence research is quite few, the threat of negative sequence component to the electrical power system's safe operation is so big.The negative sequence electric current's invasion will produce a series of higher harmonics in generator's rotor, even cause rotor's winding end seriously damage. The motor will also take the stray losses and the brake torque, the relay protection installment's wrong start will also sometimes occurs, therefore how to eliminate the negative sequence is become an electric railway's important topic.This article is in the existing idle work compensation system foundation, studies how to carry on the negative sequence idle work compensation. Base this premise, this article proposed the foreword mesh method. It uses the matrix concept to calculate the compensation conductance, utilizes the capacitor and TCR (thyristor control reactor),then constitute negative sequence idle work compensation system. This article analyzes the compensation system principle and the movement plan, and carries on the example analysis by the Zunyi power transformation behavior example. The result indicates that the installment performance index is good, the plant capacity demand is not big. Finally has carried on the simulation.