Constant measurement of induction motor

Abstract

Abstract PURPOSE:To perform automatic measurement and setting of a constant positively and easily under the stoppage of a motor even with an unknown constant, by generating a DC current from a current control type inverter to determine the constant of an induction motor from a primary voltage thereof. CONSTITUTION:A tuning control circuit 20 has a control function to regulate an output waveform of a PWM waveform generation circuit 22 and generates a DC constant current by steps using two phases of an inverter main circuit 21 when given a measurement/setting command for a constant data. Then, a primary resistance r1 of a motor 1 is obtained by a computation using the ratio V1(infinity )/I between the final value V1(infinity ) of a primary voltage V1 of an induction motor 1 and a DC current I and a secondary inductance L2 is determined from a secondary time constant tau2 of the motor 1, a secondary resistance r2 and tau2=L2/r2 using a formula based on transient voltages V1(t1) and V1(t2) of a voltage V1 by the current I at the time t1 and t2, the final value V1(infinity ) and the current I. Then, a coefficient necessary for a coefficient generating unit 93 is automatically set.

Inventors

• 👤 Masayuki Terajima
• 👤 寺嶋　正之
• 👤 Tadashi Ashikaga
• 👤 足利　正

Bibliographic Details