Abstract: 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.

Abstract: 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.

Abstract: 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.