| 摘要 |
<p>A surge suppressor completely suppresses surge voltage only by adding a simple damper circuit and thus elongates the duration of the insulation of an AC motor driven by a PWM inverter through a relatively long cable. The surge suppressor comprises a power supply for supplying AC power subjected to pulse width modulation by an inverter, an AC motor driven by AC power from the power supply through a long cable, and a damper circuit that includes either a series circuit of a resistor and a capacitor connected between the input terminals of the electric motor or a parallel circuit of a resistor and an inductor connected between the output terminals of the power supply. The circuit constants of the damper circuit are determined according to the inductance and stray capacitance of the cable so that surge can be absorbed.</p> |
