Abstract: A system and method for detecting islanding in a Distributed Generation utility grid is described. In some examples, the system, via an inverter, injects a frequency disturbance to a location of the utility grid associated with a DG generator, measures both the frequency error due to the disturbance and the frequency drift of the location of the utility grid, and determines islanding based on a maximum value of the frequencies. In some cases, the system is able to reduce or minimize the Non-Detection Zone of the inverter by detecting islanding without always relying on a detectable frequency error due to an injected waveform.

Abstract: A system and method for detecting islanding in a Distributed Generation utility grid is described. In some examples, the system, via an inverter, injects a frequency disturbance to a location of the utility grid associated with a DG generator, measures both the frequency error due to the disturbance and the frequency drift of the location of the utility grid, and determines islanding based on a maximum value of the frequencies. In some cases, the system is able to reduce or minimize the Non-Detection Zone of the inverter by detecting islanding without always relying on a detectable frequency error due to an injected waveform.

Abstract: A system and method of calculating optimum angle advance for brushless permanent magnet motors. The calculations are based on the motor and drive parameters, and on operational variables including the motor speed and the motor load. The angle advance is calculated dynamically as a function of motor speed and where reluctance torque is involved, as a function of load current as well. For a given motor, the advance is calculated according to the speed and load together with the motor and drive parameters according to one or more angle advance equations.