UNABHÄNGIGE LASTVERTEILUNG VON PARALLEL GESCHALTETEN GLEICHSTROMLEISTUNGSSYSTEMEN

摘要

A parallel redundant power supply system which does not use any inter-unit signaling is obtained by using the AC output power level of a power system to coordinate load sharing. The necessary information for load sharing is derived solely from each power system's output power level in such a manner that the output of a power system is inherently phase locked to the output of other power systems to which it is connected in parallel. Each parallel connected power system designed in accordance with the invention includes means for generating an AC output voltage from a DC input power source, means for sampling either a DC input voltage from the DC input power source or the AC output voltage from the AC output voltage generating means to provide power level samples, and means for determining the AC output power of the AC output voltage generating means from the power level samples. A control signal is then generated and provided to the AC output voltage generating means to control the AC output phase and output frequency of the AC output voltage from the AC output voltage generating means based on the output power level of the AC output voltage generating means and a derivative of the output power level of the AC output voltage generating means so as to affect load sharing in a manner proportional to a unit power rating of the power system with other power systems to which the power system is connected in parallel without requiring inter-unit signaling between the power systems. Generally, the control signal is determined by integrating the derivative of the output power level of the AC output voltage generating means as determined from the power level samples.