Abstract: A motor drive employs a combination of gas discharge tubes and metal oxide varistors to create precisely tailored surge protection that has a low leakage current minimizing the triggering of ground fault detection circuitry when multiple motor drives are attached to a single line source.

Abstract: A rectifier includes a switching circuit and a controller. The switching circuit is coupled between positive and negative buses and a plurality of input voltage sources. The switching circuit includes a plurality of pairs of switching devices. Each pair is associated with one of the input voltage sources. The controller includes first and second control loops operable to generate control signals for operating the pairs of switching devices to generate a potential across the positive and negative buses. The controller is further operable to estimate a line inductance seen by the rectifier based on at least one of the control signals and generate an inductance compensation gain factor for applying to the control loops based on the estimated line inductance.

Abstract: A power converter includes a DC to AC inverter that is connected to a neutral node formed between first and second capacitors connected across two DC supply lines. The inverter is operated to selectively couple the DC supply lines and the neutral node to an output terminal thereby producing an alternating voltage waveform formed by a sequence of output pulses having positive, zero and negative voltage levels. To compensate for a voltage imbalance across the capacitors, an imbalance compensation coefficient is derived from the difference in voltages across the first and second capacitors and from the direction of current between the neutral node and the inverter. The imbalance compensation coefficient is employed to adjust the width of the output pulses so as to charge and discharge the capacitors to correct the imbalance.

Abstract: A stator turn fault detection system and method capable of real-time detection of a stator turn fault in an electric motor is provided. The stator turn fault detector includes a feed forward neural network that when trained, using fundamental frequency sequence components of the voltage and current supplying the electric motor, will estimate a fundamental frequency sequence component of current indicative of a stator turn fault. A method for detecting a stator turn fault in an electric motor as well as a method for training a feed forward neural network for use with the stator turn fault detector is disclosed.