Traction Substation Reactive Power And Harmonic Compensation Device, And In Engineering Applications

At present, the electrical railway traction load in our country has great influence on power factor, negative sequence and hypo_harmonics. Now the affect and the measure of hypo_harmonics is in the research. The influence of negative sequence is almost eliminated along with the enlargement of the system's capacity and the alternate connection of traction substations. The fixed parallel compensate equipment applied in traction substations consist of a constant capacitor and a constant inductance, So its output is constant. This equipment is not satisfied with the requestment of reactive power and the improvement of power factor. It is over compensated when there is no traction load, Because the power department measures reactive power returning back as positive value ,The power factor of traction substations becomes more worse and railway bureau is received more penalty.Considering the random fluctuation traction load (from 0 to max, variable at every minute), the life limit of all kinds of machine switches and expensive cost and complex overhaul of SVC, this paper aims to develop a set of SVC suitable for the present condition of our country. In order to resolve the reactive power returning back problem and realize static adjustable compensation to improve negative sequence. The step-down transformer is used and TCR is replaced by TSR. Now TSC is used to compensate inadequate reactive power and TCR compensates superfluous reactive power while TSC is used to wide adjustment and TCR is used to exact adjustment.This paper is studies the practical application of static adjustable reactive compensation by adopting thyristor cross-zero-Switched on/off exact groups of capacitors or reactor rapidly. It emphases the selection of secondary voltage of the step-down transformer, the control and protection of thyristor, the calculation of compensation capability and group capability, the technique of cross-zero Switched on/off capacitors or reactor, the solution of avoiding possible resonance in Switching on/off groups of capacitors or reactor and the measure of the best time to switch (including the design of the computer survey and control system, instrument deliver system ,delay operate and protect system ).Although thyristor as a no-contact switch can avoid almost the problem of contact switch with contact, it can not solve the over-voltage, over-currentand transient process itself as switching on/off capacitors or reactor. So we must develop a set of thyristor-Switched control and protect system with great reliability so that it can realize of cross-zero switching on/off capacitors or reactor at any time.As an example, the paper presents the design of static adjustable reactive compensation with step-down transformer for Ying ShuiQiao traction substation (TSC),the design of the over compensatuion of dynaminc state imbibe system during no travelling crane(TSR), it did synthesis optimize of the mostly equipments' technology parameter ,at the same time did the analysis and evaluation in the base of colligate control strategy using computer emulate. We trial-produced a set of specimen in Ying ShuiQiao traction substation it are used in the substation in due form and recieved good effects, elevated the power factor to 0.94.