| 摘要 |
PROBLEM TO BE SOLVED: To measure the magnetic flux of a core accurately by measuring the voltage waveform of a stationary induction electric apparatus when power supply is interrupted and determining the remanent magnetic flux density by integrating the voltage waveform. SOLUTION: A magnetic flux measuring apparatus comprises a circuit breaker 2 and a sine wave power supply 3 connected with the primary of a stationary induction electric apparatus 1, and a voltmeter 4 and a computer 5 connected with the secondary of the stationary induction electric apparatus 1. When the circuit breaker 2 is opened for a sufficient time while exciting the stationary induction electric apparatus 1, induction voltage is varied. The variation is measured by the voltmeter 4 and the voltage waveform is taken into the computer 5 where the waveform of magnetic flux is determined by integrating the voltage waveform. The remanent magnetic flux is obtained by determined the difference between of the final value of the waveform of magnetic flux and the center 6 of a sine wave oscillation before interrupting power supply. Subsequently, the circuit breaker 2 is closed. Variation in the induction voltage is measured by the voltmeter 4 and the voltage waveform is taken into the computer 5 where the waveform of magnetic flux is determined by integrating the voltage waveform. The waveform of magnetic flux when power is turned on can be determined by adding a previously calculated remanent magnetic flux to the starting point of the waveform of magnetic flux.
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