Study On500kV Compact Line Arc Current

Energy distribution is uneven, due to geographical factors in China, large-capacity,long-distance transmission technology issues on the agenda. However, the compact linetransmission has a transmission capacity, transmission distance, occupied channel small.500kV compact line owns the electrical parameters with phase coupling and obviouscharacteristics of distributed parameter. Arc current and the recovery voltage are at ahigher level than the conventional line of500kV compact line. This will reduce thesuccess rate of single-phase reclosing, affecting the security and stability of the system.Therefore, this paper analyzes the generation mechanism of arc current of the500kV compact line and uses distributed parameter model to establish a mathematicalmodel of the arc current. This paper discusses the effect on the arc current according tothe mathematical model of phase-to-phase capacitor factors and derives in accordancewith full compensation neutral reactance formula. This paper discusses the effect of lineinductance on arc current and designs an arc current limiter. This paper discussesinstallation of high-speed grounding switch on the inhibition of arc current and comesup with a grounding switch configuration program. This paper uses the power systemsimulation software PSCAD to establish a reliable500kV compact line simulationmodel and make a simulation for various programs. The study shows that after theretrofit with neutral point reactance shunt reactors and high-speed grounding switch, theinhibitory effect of the arc current line comes obvious.On this basis, this paper comes up with three methods of transient faults andpermanent faults discrimination. First, this paper establishes a shunt reactor with neutralpoint reactance to calculate the compact lines lumped parameter model of the arccurrent. According to PSCAD simulation analysis, it verifies the correctness of such acriterion. Studies have shown that such a criterion has no business with transitionresistance and fault location. Second, this paper derives the expression of the arc currentonline data by phase-mode transformation and determines the nature of the fault underthe arc current value. The correctness and validity of the discrimination method isverified by simulation. Third, for compact lines, it takes into account the phasecapacitance bigger than the case of conventional type line, this paper comes up with adiscrimination by the loss of non-fault phase current, The correctness and validity of the discrimination method is verified by simulation.Finally, it makes a comparative analysis of the advantages of the three discriminationmethod. The site can be selected depending on the line conditions to the correspondingdiscrimination program. This paper provides some reference value on compact linetransmission technology engineering practice from multiple angles.