초록 ▼

A method for controlling an inverter to improve the ability of the inverter to support power factor corrected (PFC) loads under transient conditions is provided. Changes in the load being provided power by an inverter may cause the RMS output voltage level of the inverter to drop. A PFC load may res

A method for controlling an inverter to improve the ability of the inverter to support power factor corrected (PFC) loads under transient conditions is provided. Changes in the load being provided power by an inverter may cause the RMS output voltage level of the inverter to drop. A PFC load may respond to such drops in the applied voltage level by increasing its current demand. This may cause the inverter current limit to be reached, forcing the inverter to be turned off, and causing the load to be dropped. This problem is avoided by responding to such load changes by immediately increasing the RMS output voltage level of the inverter to a level sufficient to minimize the voltage drop and prevent excessive current demands from the PFC load. The output voltage level of the inverter is then gradually reduced from the high voltage level to prevent the occurrence of oscillations due to interactions between the PFC load and the inverter controller. The present invention may be applied to backup power systems employing square wave inverters. In response to load changes, or transitions between line power and inverter operation following the detection of a line power fault, the inverter pulse width is immediately increased to an approximately maximum pulse width. The pulse width is then gradually reduced in increments to the pulse width required to maintain a constant regulated output RMS voltage level on the inverter under steady state conditions.

대표청구항 ▼

[ What is claimed is:] [1.] A method for controlling an inverter to provide an output voltage waveform on an output of the inverter for providing power to a power factor corrected load, comprising the steps of:(a) controlling the inverter to provide a regulated output voltage waveform at a desired s

[ What is claimed is:] [1.] A method for controlling an inverter to provide an output voltage waveform on an output of the inverter for providing power to a power factor corrected load, comprising the steps of:(a) controlling the inverter to provide a regulated output voltage waveform at a desired steady state RMS voltage level;(b) determining the occurrence of a transient load change condition that causes the RMS voltage level of the output voltage waveform to drop suddenly;(c) responding to the determination of the occurrence of the transient condition by controlling the inverter to rapidly increase the RMS voltage level of the output voltage waveform to a high RMS voltage level; and(d) controlling the inverter to gradually decrease the RMS voltage level of the output voltage waveform from the high RMS voltage level down to the desired steady state RMS voltage level.