Powerware Corporation

Eaton Corporation

Eaton Intelligent Power Limited

Miguel Eduardo Chavez

Frederick Tassitino, Jr

John Gaylord Tracy

Jason Scott Anderson

Rune Lennart Jonsson

Hans-Erik Pfitzer

Edward Akbari

Angelo Louis Mandarino

Fred Tassitino

Some embodiments of the inventive subject matter provide a system including a plurality of power supply units having AC inputs configured to be coupled to an AC power source and AC outputs coupled to respective first busses. Each of the power supply units includes an uninterruptible power supply (UPS) having an output configured to be coupled to the AC output of the power supply unit, a first switch configured to selectively couple the AC input to the AC output of the power supply unit, and a second switch configured to selectively couple the AC output of the power supply unit to a second bus. The system may further include at least one control circuit configured to control first and second ones of the power supply units to enable the first one of the power supply units to provide power to the first bus coupled to the second power supply unit from the first power supply unit via the second bus.

Multi-UPS systems with coordinated fault response and power sharing using paralleling bus

A power supply apparatus includes first and second parallel-connected uninterruptible power supplies (UPSs), each including an AC/DC converter circuit and a DC/AC converter circuit having an input coupled to an output of the AC/DC converter circuit by a DC link, inputs of the AC/DC converter circuits of the first and second UPSs connected in common to an AC source and outputs of the DC/AC converter circuits of the first and second UPSs connected in common to a load. The first and second UPSs are configured to support a test mode wherein the first UPS is test loaded by transferring power from the output of the DC/AC converter circuit of the first UPS to the output of the DC/AC converter circuit of the second UPS. The first UPS may be configured to provide power to the load concurrent with test loading by the second UPS.

Self-testing power supply apparatus, methods and computer program products

Twelve-pulse rectifiers include a first controller that controls a first six-pulse rectifier, a second controller that controls a second six-pulse rectifier and a data network that couples the first controller and the second controller to exchange data therebetween. The first and second controllers preferably have a common architecture and preferably operate independently. Each controller preferably controls its associated six-pulse rectifier as a function of the current and/or voltage output of the associated six-pulse rectifier, preferably using conventional feedback control techniques. Moreover, the first controller also preferably controls the first six-pulse rectifier as a function of a second current at the second six-pulse rectifier output, and the second controller preferably controls the second six-pulse rectifier as a function of a first current at the first six-pulse rectifier output. Thus, each six-pulse rectifier may be controlled as a function of the current at the other six-pulse rectifier output. The first controller preferably receives second data representing the second current at the second six-pulse rectifier output via the data network, and the second controller preferably receives first data representing a first current at the first six-pulse rectifier output via the data network. The first controller preferably continues to control the first six-pulse rectifier upon failure of the second controller to thereby provide a first output current from the first six-pulse rectifier at the twelve-pulse rectifier output. Similarly, the second controller preferably continues to control the second six-pulse rectifier upon failure of the first controller to thereby provide a second output current from the second six-pulse rectifier at the twelve-pulse rectifier output. When the first and second controllers are operational, the first and second six-pulse rectifiers may be controlled by their respective first and second controllers.

Twelve-pulse rectifiers including separate six-pulse controllers and methods of controlling same

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.

Apparatus and methods for space-vector domain control in uninterruptible power supplies

Growing community of inventors

Raleigh, NC, United States of America

Miguel Eduardo Chavez