电力系统保护与控制
電力繫統保護與控製
전력계통보호여공제
POWER SYSTM PROTECTION AND CONTROL
2013年
23期
23-29
,共7页
船舶中压电网%消弧线圈接地%熄弧恢复电压%重燃过电压%故障电流
船舶中壓電網%消弧線圈接地%熄弧恢複電壓%重燃過電壓%故障電流
선박중압전망%소호선권접지%식호회복전압%중연과전압%고장전류
shipboard medium voltage (MV) power grid%resonant neutral grounding (RNG)%arc-extinct recovery voltage%re-strike overvoltage%fault current
消弧线圈接地方式用于船舶中压电网时,对其机理和规律迄今还缺乏定量研究。在对船舶中压电网单相接地故障进行理论分析的基础上,结合暂态仿真,研究了消弧线圈阻尼率、脱谐度以及发电机频率偏移、燃弧时刻角等对熄弧恢复电压、重燃过电压、中性点位移电压以及故障电流的影响。结果表明,增大阻尼率将减小熄弧电压恢复超调量,从而降低重燃过电压,但也会使故障电流有所增加;而增加脱谐度会使得熄弧电压恢复超调量增加,可能引起较大的重燃过电压,为了限制故障电流,脱谐度不宜取值过大;此外,发电机频率偏移也可能导致较大的暂态过电压。
消弧線圈接地方式用于船舶中壓電網時,對其機理和規律迄今還缺乏定量研究。在對船舶中壓電網單相接地故障進行理論分析的基礎上,結閤暫態倣真,研究瞭消弧線圈阻尼率、脫諧度以及髮電機頻率偏移、燃弧時刻角等對熄弧恢複電壓、重燃過電壓、中性點位移電壓以及故障電流的影響。結果錶明,增大阻尼率將減小熄弧電壓恢複超調量,從而降低重燃過電壓,但也會使故障電流有所增加;而增加脫諧度會使得熄弧電壓恢複超調量增加,可能引起較大的重燃過電壓,為瞭限製故障電流,脫諧度不宜取值過大;此外,髮電機頻率偏移也可能導緻較大的暫態過電壓。
소호선권접지방식용우선박중압전망시,대기궤리화규률흘금환결핍정량연구。재대선박중압전망단상접지고장진행이론분석적기출상,결합잠태방진,연구료소호선권조니솔、탈해도이급발전궤빈솔편이、연호시각각등대식호회복전압、중연과전압、중성점위이전압이급고장전류적영향。결과표명,증대조니솔장감소식호전압회복초조량,종이강저중연과전압,단야회사고장전류유소증가;이증가탈해도회사득식호전압회복초조량증가,가능인기교대적중연과전압,위료한제고장전류,탈해도불의취치과대;차외,발전궤빈솔편이야가능도치교대적잠태과전압。
At present, a quantitative research on the mechanisms and laws of the application of resonant neutral grounding (RNG) to shipboard medium voltage (MV) power grid is scarce. Based on the theoretical analysis of single-phase to ground fault for shipboard MV power grid, combining with transient simulation, the paper studies the impact of damping ratio and tuning degree of arc-suppression coil on arc-extinct recovery voltage, re-strike overvoltage, neutral displacement voltage and fault current. The effects of generator frequency offset and arc angle are also discussed. The results show that increasing the damping ratio will decrease the arc-extinct voltage recovery overshoot, thereby reducing re-strike overvoltage, but will also increase fault current. While increasing tuning degree will increase the arc-extinct voltage recovery overshoot, and possibly cause greater re-strike overvoltage, so the tuning degree should be appropriate to restrict the fault current. In addition, the generator frequency offsets can also lead to greater transient overvoltage.