Powerware Corporation

Edward Akbari

Hong Zhang

Des Faria

Piotr Grudzinski

Frederick Tassitino, Jr

Miguel Eduardo Chavez

Ove Ohman

A power supply apparatus includes an AC input port, an output port, and a bypass circuit that couples the AC input port to the output port. An AC/DC converter circuit, e.g., a rectifier circuit, produces a DC voltage from an AC input voltage at the AC input port. A DC/AC converter circuit, e.g., a current mode controlled inverter, controls current transfer between the output port and the AC/DC converter circuit responsive to a control input such that respective first and second component currents of a current delivered to a load coupled to the output port pass via respective ones of the bypass circuit and the DC/AC converter circuit. The DC/AC converter circuit may be operated such that current passing through the bypass circuit is constrained to be substantially in phase with the AC input voltage. The power supply apparatus may have another mode of operation in which the DC/AC converter circuit exclusively provides power to the output port, and may include an auxiliary DC power supply circuit that provides a DC voltage to the DC/AC converter circuit. Related power supply methods are also discussed.

AC power supply apparatus with economy mode and methods of operation thereof

A power supply apparatus includes an AC input port and a rectifier circuit, coupled to the AC input port, that produces a DC voltage at a rectifier circuit output from an AC input voltage at the AC input port. The apparatus further includes a selective harmonic current inducing circuit, coupled to the rectifier circuit output, that induces a harmonic component in a current delivered to a load from the rectifier circuit output. The selective harmonic current inducing circuit may control a phase and a magnitude of the induced harmonic current component in order to achieve selective suppression of a harmonic input current at the AC input port. The power supply apparatus may further include a filter circuit, coupled to the AC input port, that selectively suppresses a first harmonic current at the AC input port. The selective harmonic current inducing circuit may control the phase and magnitude of the induced harmonic current component such that a second harmonic current at the AC input port is suppressed. For example, for a three-phase passive rectifier circuit, the filter circuit may suppress a fifth harmonic input current, and the selective harmonic current inducing circuit may control the phase and magnitude of an induced sixth harmonic current component such that a seventh harmonic input current at the AC input port is suppressed. Related methods are also discussed.

Power supply apparatus with selective rectifier harmonic input current suppression and methods of operation thereof

Uninterruptible power supplies (UPSs), power conversion apparatus and power conversion methods are provided which may improve phase regulation of polyphase AC voltages in the presence of load imbalances. According to one embodiment, a UPS includes a DC voltage generating circuit that produces a DC voltage. A space vector domain controlled inverter couples the DC voltage generating circuit to an AC load, and produces a polyphase AC output voltage at the load by sensing a plurality of voltages at the load, transforming the plurality of sensed voltages according to a space vector (d-q) transformation to produce an output space vector, generating an error space vector from the output space vector and a reference space vector, and selectively coupling the DC voltage generating circuit to the load responsive to the error space vector. In this manner, a voltage control loop is closed in the d-q domain, which may improve per-phase regulation of the polyphase AC output. Preferably, compensation is applied to the error space vector to produce a control space vector that compensates for poles or other transfer characteristics of the forward path of the voltage control loop. In another embodiment, the reference space vector is generated by an outer voltage amplitude loop that compares a sum of the plurality of output voltages at the load to a reference voltage amplitude, generating an error amplitude voltage which is compensated and then transformed according to a space vector transformation to produce the reference space vector that serves as the set point for the inner space vector domain control loop.

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CA

Edward Akbari