| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a control device of a winding type induction motor that speed-variably drives a pump, a fan or the like, for example, by using a so-called stationary scherbius method. <P>SOLUTION: Both-end voltages of a capacitor 6 are monitored by a state monitoring circuit 30, and when either a state that the voltages deviate from a range of ±10%, for example, of a rated voltage applied to the capacitor 6, or a state that a stop state signal from an inverter control circuit 32 is output is created, a command is transmitted to a secondary switching control circuit 31, and in the secondary switching control circuit 31 that receives the command, a contactor S<SB>1</SB>and a contactor S<SB>2</SB>are operated in order to switch the supply of a secondary output of the winding type induction motor 2 to a secondary resistor 11 side from a diode rectifier 3 side. As a result, damages in these states to semiconductor elements that constitute a chopper main circuit 5 and an inverter main circuit 7, respectively are prevented in advance. <P>COPYRIGHT: (C)2005,JPO&NCIPI |
