| 摘要 |
PURPOSE:To easily and surely perform an automatic measurement by applying a DC voltage to the primary input of an induction motor from a power inverter, measuring the primary input current and voltage of the motor, finding the primary parameters and calculating the secondary parameters based on prescribed equations. CONSTITUTION:With transistors Tr1, Tr6, etc. in an inverter 21 of the driving power source switched on and off, while a PWM waveform generating circuit 22 set with a definite voltage by a control circuit 11, DC voltage pulses are impressed on the windings U, W, etc. of an induction motor 1. Thus, the voltage and current are measured through a voltage and current detectors 12, 13, and from their ratio, the resistance r1 as a primary parameter is determined by the circuit 11. On the other hand, from the rising transient currents i1(t), i2(t) and the end current Ie of the DC current I, rising time constant T of the current I is determined, and the secondary resistance r2, secondary inductance L2 as the secondary parameters are determined based on the equation 1. In this manner, an automatic measurement of the parameters can be made easily and surely in a standstill state of the motor. |
