| 摘要 |
<p>An emergency power system is connected between an AC voltage source (10) on the input and a load (Z) on the output. The emergency power system ensures a stable voltage on the output, even if the AC voltage received from the AC voltage source (10) is irregular or is interrupted briefly. The emergency power system comprises an AC/DC converter (14) coupled between its output terminals and an AC regulator (20) positioned between the input and the output. The AC/DC converter (14) is coupled to a chargeable battery (12) and serves as a charging rectifier for the battery (12) in normal operation and as an inverter in emergency operation, the battery voltage being converted to AC voltage on the output of the emergency power system. This can be done without changing the control of the converter (14) and the regulator (20). The AC regulator (20) is built as a controllable current generator supplying on its output an AC current which is in phase with the AC voltage received from the AC voltage source (10). Irrespective of the energy direction through it, the AC/DC converter (14) maintains the predetermined AC voltage (VOUT) across the output terminals of the emergency power system. The system moreover includes a comparison means (28) which senses and compares the battery state to a predetermined reference and supplies a signal in response to this. The intensity of the current supplied by the regulator (20) is controlled in response to the signal generated by the comparison means (28), so that in terms of energy the system is in power balance.</p> |
