A protection method and system for exciting winding interphase short circuit faults of an alternating current excitation synchronous motor
A technology of excitation windings and synchronous motors, applied in the direction of automatic disconnection emergency protection devices, circuit devices, emergency protection circuit devices, etc., can solve problems such as reducing the response speed of relay protection equipment to short-circuit faults
Active Publication Date: 2018-02-02
NR ELECTRIC CO LTD +1
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AI-Extracted Technical Summary
Problems solved by technology
The invention provides a protection method and system for exciting winding interphase short circuit faults of an alternating current excitation synchronous motor. The method comprises the steps of: firstly collecting three-phase exciting winding currents of a motor; calculating an absolute value of current instantaneous values and a current effective value according to the collected currents; during decision making for over-current protection, setting an over-current instantaneous value criterion as the main criterion and an over-current effective value criterion as an auxiliary criterion; performing accumulative counting on moments which meet the current instantaneous value out-of-limit criterion or which do not meet the current instantaneous value out-of-limit criterion but meet the current effective value out-of-limit criterion by using a time delay counter; performing progressive subtraction on moments which do not meet the current instantaneous value out-of-limit criterion and thecurrent effective value out-of-limit criterion; further determining the over-current protection start, operation and start return time according to values of the time delay counter. The method combines the rapidness of the instantaneous value criterion and the reliability of the effective value criterion and can rapidly reflect exciting winding interphase short circuit faults of an alternating current excitation synchronous motor.
Emergency protective arrangements for automatic disconnection
Return timeTime delays +10
- Experimental program(3)
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