Abstract: The present invention is a control architecture for an active rectifier. The control architecture monitors the AC input voltage provided to the active rectifier at a sampling rate grater than the frequency of the AC input voltage and calculates, in response, a phase estimate associated with the monitored AC input voltage that is updated with each new sample of the AC input voltage. Based on the phase and frequency estimates, along with monitoring of the AC input current and DC output voltage, the control architecture calculates voltage commands that are used to generate the pulse-width modulation (PWM) controls signals for provision to solid-state switching devices in the active rectifier.

Abstract: An example overvoltage protection device includes a switch and a link current sensor that measures current through the switch. The overvoltage protection device is selectively activated by transitioning the switch between an off-state and an on-state. The switch is transitioned from the on-state to the off-state in response to a current measurement from the DC link current sensor. The current sensor is a DC link current sensor in one example.

Abstract: An example, overvoltage protection device includes a switch and a surge protection device that is selectively activated by actuating the switch. The switch is actuated in response to a voltage. An example method of absorbing an overvoltage includes sensing a voltage, and selectively activating a surge protection device in response to the sensed voltage.

Abstract: A phase detection system includes a low-resolution sensor and a high-resolution sensor for monitoring an alternating current (AC) voltage. A phase detector receives voltage samples from both the low-resolution sensor and the high-resolution sensor. The phase detector monitors the low-resolution sensor to detect approaching zero cross events (i.e., monitored voltage values approaching zero). In response to an approaching zero-cross event, the phase detector uses the magnitude of the high-resolution voltage samples measured on either side of the zero cross event to determine the phase of the monitored AC voltage.

Abstract: An active rectification system includes a three-level active rectifier and a pulse with modulation (PWM) control portion. The three-level active rectifier includes at least three switches, the at least three switches are selectively switchable between an upper state, a center state, and a lower state. The PWM control portion is in communication with the at least three switches, the PWM control portion is configured and disposed to create an upper carrier signal and a lower carrier signal, and the PWM control portion is configured and disposed to selectively switch the at least three switches between the upper state, the center state, and the lower state in response to a phase disposition of the upper carrier signal and the lower carrier signal.