Abstract: A method and apparatus for improving the speed measurement quality in systems having multi-pole machines is taught. The method compensates for pole misalignment by moving average techniques.

Abstract: Cycle error correction is performed in an electronic power system to compensate for a difference between an AC grid side frequency and an AC load side frequency. The electronic power system can comprise an electronic power inverter, such as one usable with an uninterruptible power supply. Cycles of signals indicative of the AC grid power and the AC load power are counted and compared to obtain a cycle error value. If the cycle error value exceeds a first value to indicate that AC load side frequency is too high or too low, then compensation is performed to change the AC load side frequency to be closer to the AC grid side frequency. If the cycle error value falls below a second value to indicate that the AC grid side frequency and AC load side frequency are sufficiently close to one another, then the compensation is deactivated.

Abstract: A system comprising a current sensor to sense a current provided by an electronic power converter, the current sensor comprising an output; an overcurrent detection circuit comprising an input coupled to an output of the current sensor; and a logic control circuit configurable to maintain the current provided by the electronic power converter in response to the sensed current having a short circuit magnitude, the logic control circuit comprising an input coupled to an output of the overcurrent detection circuit and at least one output coupled to at least one switch of the electronic power converter.

Abstract: A power system employs an outer voltage feedback loop and an inner current feedback loop to control a power converter, such as a DC to AC inverter for transferring electrical power between a power source, for example a photovoltaic array, and a load, for example a power grid. The outer loop accommodates variations in the output of the power source, for example accommodating anomalies in IV characteristics such as IV droop characteristic associated with photovoltaic cells. The outer loop may employ a first control regime or a second control regime, for example, dependent on whether a DC bus voltage or power is smaller than a value corresponding to measurement resolution or expected noise.