Three-phase current sensor for motor protection against turn-to-turn and phase-to-phase short circuits

3rd International Scientific and Technical Conference “Energy Systems”

Ishmukhamedov, I.K.^1

Department of Electrical Engineering and Electrical Facilities of Enterprises, Ufa State Petroleum Technological University, Kosmonavtov St. 1, Ufa

450062, Russia^1

关键词: AT power supplies;    Electric consumers;    Electrical installations;    Electrical plants;    High-speed protection;    Protection device;    Three-phase currents;    Turn-to-turn faults;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/552/1/012014/pdf
DOI  :  10.1088/1757-899X/552/1/012014

来源: IOP

【 摘 要 】

The main causes of electric motor failures are transients at power supply interruption and short circuit in stator windings. Most of the failures are due to short circuits. Phase-To-phase short circuits refer to the most severe damage of electrical installations, which are also dangerous for other intact electric consumers. Therefore, electrical plants require a high-speed protection against phase-To-phase short circuits in the stator windings and connections with the commutator. The most difficult to detect are turn-To-Turn (or inter-Turn) faults in stator windings, especially when a small number of winding turns is shorted. Currently, there is no standard way to detect turn-To-Turn short circuits in stator windings. It is difficult to detect turn-To-Turn fault in magnitude of phase currents, so it is complicated to provide sufficient protection sensitivity. Thus, the development of new protection devices for detect turn-To-Turn short circuit is considered relevant. The article presents a three-phase current sensor based on measuring the magnetic field from the three phases simultaneously. This method will identify turn-To-Turn and phase-To-phase short circuits by magnetic-field pattern. The presented method increases the protection sensitivity and speed of protection response. The effectiveness of the proposed method is demonstrated by mathematical modeling.