ATP-EMTP Investigation of a New Distance Protection Principle for Series Compensated Lines

摘要: Abstract – A new algorithm for the first zone of protective distance relays transmission lines compensated by series capacitors, installed in middle and at both ends, is pre-sented. The concept relies on determining two conditional impedances comparing them with three characteristics specially shaped impedance plan. im-pedances are calculated from fault loop quantities com-posed as classic relays, but case voltages additionally compensation voltage drop across bank (or banks) capacitors performed. sample cases evaluation results developed algo-rithm presented. ATP-EMTP package has been used simulation versatile faults generating reliable data algorithm. Keywords series-compensated line, capacitor bank, non-linear circuit, algorithm, ATP-EMTP, I. I NTRODUCTION Both, technical economical benefits resulting using power trans-mission well-recognized known [1]. At same time such considered system items, which extremely difficult protecting [2]-[7] well locating [8]. In this paper a protection principle line phase (Fig. 1a), or banks ends 1b), investigated. Series Capaci-tors (SCs) equipped Metal-Oxide Varistors (MOVs) 2a, b), when set create certain problems its devices. Under behind SCs&MOVs becomes strongly nonlinear, consequence nature transients, steady state situation, entirely different, traditional lines. Operation thermal (TP) MOV sparks associated air-gap thus shunts MOV. However, high speed tripping basically prior to operation TP there no need reflect within consid-ered here Direct application (de-signed lines) considerable shortening reach also poor transient behavior order over-come these difficulties princi-ple developed.