Abstract: Method and apparatus for determining transient power source defects versus nontransient, grid failures result in power being selectively applied to a DC bus for application to a load by either the power source, a rechargeable DC power supply, or both. The severity of the power interruption determines the degree to which the power will be supplied to a load through a power converter assembly by either an AC source or a rechargeable DC power supply.

Abstract: Circuits and methods for use with an integrated circuit chip having internal back EMF estimation to control a permanent magnet synchronous motor includes an AC current feedback circuit, a scaling circuit, and a current regulator. Additionally, a speed regulator may be employed. In one embodiment, during operation at very low speed, the speed regulator is in an open loop control mode due to a back EMF detection limitation of the IC chip, and only the current regulator is active. A feedback current signal, together with a user-defined command current signal, serves the input of the current regulator, which controls the AC motor current and drives the motor speed from standstill. Once the motor speed reaches a certain level, the measured back EMF from the IC chip is sufficient to estimate the motor speed, which is compared with a user-defined command speed, and an error of the these two signals provides the input of a speed regulator.

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: An electrical power converter system adjusts a wakeup voltage periodically, to permit earlier connection and/or operation, to increase performance. The electrical power converter system selects between a mathematically adjusted wakeup voltage based on at least one previous period, and a table derived wakeup voltage that takes into account historical information. The electrical power converter system is particularly suited to applications with periodicity such as solar based photovoltaic power generation.

Abstract: A power conversion system which comprises a controller and conversion assemblies which selectively rectify and invert an electrical signal. Conversion assemblies comprise a plurality of integrated gate bipolar transistor assemblies. The power conversion system is effective to convert DC current to AC current, to convert AC current to DC current, and to control the output frequency of a received electrical signal to a conventional operating range.

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.

Abstract: A power conversion system which comprises a controller and conversion assemblies which selectively rectify and invert an electrical signal. Conversion assemblies comprise a plurality of integrated gate bipolar transistor assemblies. The power conversion system is effective to convert DC current to AC current, to convert AC current to DC current, and to control the output frequency of a received electrical signal to a conventional operating range.

Abstract: Circuits and methods for use with an integrated circuit chip having internal back EMF estimation to control a permanent magnet synchronous motor includes an AC current feedback circuit, a scaling circuit, and a current regulator. Additionally, a speed regulator may be employed. In one embodiment, during operation at very low speed, the speed regulator is in an open loop control mode due to a back EMF detection limitation of the IC chip, and only the current regulator is active. A feedback current signal, together with a user-defined command current signal, serves the input of the current regulator, which controls the AC motor current and drives the motor speed from standstill. Once the motor speed reaches a certain level, the measured back EMF from the IC chip is sufficient to estimate the motor speed, which is compared with a user-defined command speed, and an error of the these two signals provides the input of a speed regulator.

Abstract: A device and method for detecting islanding operation of a static power source involves injection of a non-harmonic error on the phase angle of the static power source in regular steps to introduce a very small intentional phase shift for the output voltage of the static power source in every voltage cycle which is corrected in each cycle in synchronization with the grid voltage in normal operation of the grid. In abnormal operation of a grid loss, this intentional small phase shift or error causes an intentional small frequency drift in each voltage cycle that continues in one cycle after another cycle. When the intentional frequency drift is over a preset level, a detection circuit starts to isolate the static power source from the grid to prevent islanding operation.