Hamilton Sundstrand Corporation

Si Jian Fang

Gregory I Rozman

Richard Andrew Himmelmann

Steven J Moss

Waleed M Said

James H Clemmons

A DC power generating system includes a permanent magnet generator (PMG), an active rectifier in electrical communication with the PMG, and a controller in electrical communication with the active rectifier, wherein the controller is configured to regulate d-q components of a stator current of the PMG in a synchronous reference frame.

High voltage DC power generation

An active rectifier controller decouples measurements of the phase and speed of a variable frequency synchronous generator from measurements of the AC output voltage. The active rectifier controller receives position information representative of the rotor position of the VFSG independent of a load connected to the VFSG that is used to determine the phase position and speed of the VFSG. Based on measurements of the generator speed and phase, the active rectifier controller controls the active rectifier to draw AC currents in-phase with the back-electromotive force (BEMF) voltage of the VFSG.

Active rectification for a variable-frequency synchronous generator

A permanent magnet comprises a primary winding, a secondary winding, a permanent magnet, an output terminal for connection to an external load, and a switching mechanism with two modes. In a first mode of the switching mechanism, the primary winding is connected between neutral and the output terminal, and the varying magnetic flux from the permanent magnet induces a nonzero voltage at the output terminal. In the second mode, the secondary winding provides a return path to neutral for the primary winding, thereby providing negligible voltage and current at the output terminal and substantially canceling change in magnetic flux from the permanent magnet.

Flux cancellation in a permanent magnet generator

A universal alternating current (AC) inverter system with galvanic isolation takes an unregulated direct current (DC) input and provides a high-quality AC output that may be used in conjunction with both linear and non-linear loads. The universal AC inverter system includes a DC-DC converter for converting an unregulated DC input to a regulated DC output, and a DC-AC inverter for converting the regulated DC output to a high-quality AC output. The DC-DC converter includes a DC link isolation high frequency transformer that provides galvanic isolation between the unregulated DC input and the AC output. To avoid saturation of the transformer, the controller for the DC-DC converter employs a DC offset correction loop that prevents accumulation of DC content on the primary side of the transformer. The universal AC inverter system includes a 4-phase inverter topology that converts the regulated DC voltage provided by the DC-DC converter to an AC output. An inverter controller employs a number of feedback loops that are used to control switches within the 4-phase inverter topology to provide a high-quality AC output voltage for both linear and non-linear loads, including a fast voltage control loop, a slow voltage control loop, a AC output capacitor current control loop, and a DC content control loop.

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Carpentersville, IL, United States of America

Si Jian Fang