DK432281A - EMERGENCY POWER UNIT - Google Patents

Abstract

In an emergency power unit for an alternating current consumer, there is a connection 9 to an alternating current generator 10, and a battery 5 which can be charged with rectified current from the alternating current generator 10, a controllable reversible rectifier 6 which is arranged between the battery and a consumer connection 2, an alternating voltage regulator 13 which stabilises the alternating voltage at the alternating voltage side 3 of the reversible rectifier 6 during pulse width modulation, and a battery voltage regulator 12. The alternating current generator 10 can be connected in parallel with the alternating voltage side of the reversible rectifier 6, and a current limiting resistor 8 is arranged between the alternating voltage side 3 of the reversible rectifier 6 and the alternating current generator's connection 9. In order to accomplish a galvanic separation between the reversible rectifier and the alternating current generator, or between the consumer 1 and the alternating voltage generator 10, the current limiting resistor is configured as a stray field transformer 8' with three windings. Of these one 31 lies directly at the alternating voltage side 3 of the reversible rectifier, the second 32 at the alternating current generator's connections 9, 9a and the third 33 at the consumer's connections 2, 2a. The stray field transformer provides not just a galvanic separation, but at the same time because of its stray inductances it also produces the necessary current limitation. <IMAGE>