Abstract: A method, apparatus and computer program for detecting an AC chassis fault on one or more DC/AC converters having a load is disclosed, including receiving a chassis voltage VChassis signal from between DC link and a chassis ground from the DC/AC converter, capturing a side band harmonic of the chassis voltage VChassis signal, determining a peak magnitude value related to the side band harmonic, comparing the peak magnitude value to a predetermined threshold value, wherein if said peak magnitude value equals or exceeds the predetermined threshold value, an AC chassis fault condition is detected.

Abstract: A method, apparatus and computer program for detecting an AC chassis fault on one or more DC/AC converters having a load is disclosed, including receiving a chassis voltage VChassis signal from between DC link and a chassis ground from the DC/AC converter, capturing a side band harmonic of the chassis voltage VChassis signal, determining a peak magnitude value related to the side band harmonic, comparing the peak magnitude value to a predetermined threshold value, wherein if said peak magnitude value equals or exceeds the predetermined threshold value, an AC chassis fault condition is detected.

Abstract: Independent phase output voltage control for a 3-phase 4-wire DC/AC inverter, for example, is provided. With the independent phase output voltage control, all three phase output voltages from the DC/AC inverter can be separately and effectively controlled to provide balanced 3-phase voltages from the DC/AC inverter to an unbalanced load, and/or to provide unbalanced 3-phase voltages from the DC/AC inverter to a balanced or unbalanced load. The independent phase output voltage control method can be applied to an inverter power system, with outputs of N-phase (N+1) wire configurations. Here, N can be any integer number greater than zero.