Maimaita Synchronization ko da Controlled Switching Device

Idan an kuma kirkiyar da ya shiga tsarin da ya yi aiki don kama muhimmanci, yana da kyau a kan hanyar kama da tsawon karamin zabe da ya shiga zero crossing of the current waveform. Amma a cikin gaba, ba a zama wani abubuwan da za a iya saukar da shi. A cikin kirkiyar na gaba, ya kamata a yi kama da tsawon karamin zabe a lokacin da ya shiga zero crossing point amma bai shiga zero crossing point of the current waveform. Saboda muhimmanci na da aiki, wannan karshe na karamin zabe, yana taka di/dt mai yawa wanda yake taimakawa waɗannan transient voltage a cikin tsari.

A cikin tsari mai girgiza ko mai tsawo masu yawan volts, wannan transient voltage a lokacin da kirkiyar ya yi aiki ba zai iya tabbatar da tasirin tsari, amma a cikin extra and ultra-high voltage systems, wannan yana da nasara. Idan bayanen contacts a cikin kirkiyar ba suka fi dace ne a lokacin da ya shiga kama da tsawon karamin zabe, zai iya samun re-ionization between the contacts saboda transient over voltage, saboda haka arcing zai iya duba.
Idan an kama da muhimmanci kamar transformer ko reactor, idan kirkiyar ya shiga tsari a lokacin da ya shiga zero crossing, zai iya samun DC component mai yawa na karamin zabe. Wannan zai iya sature core of transformer or reactor. Wannan zai iya haɗa da inrush current mai yawa a cikin transformer or reactor.
Idan an kama da kirkiyar don lura muhimman daidai a cikin tsari, kamar capacitor bank, yana da kyau a lura current path a lokacin da ya shiga zero crossing of system voltage waveform.

Saboda hakan, ba a cikin karfin kirkiyar, high inrush current zai faru a cikin tsari. Wannan zai iya haɗa da over voltage a cikin tsari ba.

Wannan inrush current tare da over voltage stress mechanically and electrically, capacitor bank da wasu abubuwa a line.
Gaba, a cikin kirkiyar, duk uku phase suna shiga ko kuma kama ne a lokacin da ke dace. Amma akwai 6.6 ms time gap between the zero crossings of two adjacent phases of three phase system.

Akwai wani aiki da ake koyar da ita a cikin relay and control panel don taimakawa waɗannan transient behavior of voltage and current during switching. Wani aiki take synchronize the switching of individual pole of >kirkiyar according to the zero crossing of corresponding phase. Wani aiki shine phase synchronizing device, in short PSD.

Yanzu ake kira kuma controlled switching device ko CSD.
Wani aiki take voltage waveform from potential transformer of bus or load, current waveform from current transformers of the load, auxiliary contact signal and reference contact signal from circuit breaker, closing and opening command from control switch of the circuit breaker installed in control panel. Voltage and current signal from each phase are required to identify exact instant of zero crossing of the waveform of individual phase. Breaker contact signals are required to calculate the operational delay of the circuit breaker, so that the opening or closing pulse to the breaker can be send accordingly, to match the interruption and zero crossing of either current or voltage wave, as per requirement.

Wani aiki shine dedicated for manual operation of the kirkiyar. A lokacin da ya shiga faulty tripping, trip signal to the circuit breaker is directly sent from the protection relay assembly, bypassing the device. The Phase Synchronizing Device or PSD may also be associated with a bypass switch which can bypass the device from the system if required in any situation.

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