Title:
PROTECTIVE DEVICE FOR INVERTER
Document Type and Number:
Japanese Patent JPS5694972
Kind Code:
A
Abstract:
PURPOSE:To protect the inverter from a short-circuit current by a method wherein a reactor and a resistor inserted at detecting an overcurrent are provided between a DC power source and the inverter, in the inverter having the DC power source small in an internal impedance. CONSTITUTION:The DC power source 13 is obtained by means of a diode bridge 15 and a capacitor 16 from an AC power source 10. To the DC power source 13, a reactor 1 to which a diode inverse to the polarity of the power source is connected in parallel, and a resistor 3 to which a transistor 4 is connected in parallel are connected, and the inverter is connected between output terminals 19 and 20. If a load is shortened or a commutation of the inverter is failed, the short-circuit current is suppressed in the rate of rise by the reactor 1 and increases. If the current increases to a predetermined value, the outputs of an overcurrent detdctor 6 and a comparator 5 cause the transistor 4 to be turned OFF and effect insertion of the resistor 3, and at the same time, release an electromagnetic contactor from the excitation, open contacts 21, 12 and close a contact 17.
Inventors:
MORI SADAO
Application Number:
JP17203079A
Publication Date:
July 31, 1981
Filing Date:
December 26, 1979
Export Citation:
Assignee:
MATSUSHITA SEIKO KK
International Classes:
H02H7/122; (IPC1-7): H02M7/48
Domestic Patent References:
| JPS50139952A | 1975-11-10 | |||
| JPS5022246A | 1975-03-10 |