North Carolina State University

Siemens Energy, Inc.

Electric Power Research Institute Incorporated

Rensselaer Polytechnic Institute

Tennessee Valley Authority

Abdel-Aty Edris

Qin Huang

Bruce Fardanesh

Michael R Ingram

Joe Hong Chow

Siriroj Sirisukprasert

Xuan Wei

Joe H Chow

An apparatus () for controlling a voltage on a transmission line (). The apparatus () comprises a first voltage sourced converter controller () connected to a first node () of the transmission line (); a second voltage sourced converter controller () connected to a second node () of the transmission line (), the second node () spaced apart from the first node () wherein the first voltage sourced converter controller () supplies capacitive reactive current and the second voltage sourced converter controller () absorbs inductive reactive current to control the voltage.

Automatic self-adjusting voltage controller

A method of balancing the voltage of DC links in a cascaded multi-level converter (CMC) semiconductor circuit, including the steps of providing a plurality of H-bridge converters per phase in the CMC circuit and utilizing a three phase duty cycle value from the main controller to determine a normalized duty cycle value, a ceiling duty cycle value and a floor duty cycle value. The normalized duty cycle value and an output current of the CMC is used to determine the direction and polarity of a capacitor current, and utilizing the capacitor current to determine a plurality of output capacitor voltages. A voltage summation result and direction is obtained from a ceiling index pointer and a floor index pointer and the voltage summation result, direction from the ceiling index pointer and a floor index pointer are used to create a combined switching table for the H-bridge converters. A pulse width modulator is utilized to balance the voltage of the DC links and thereby eliminate DC-capacitor voltage imbalance.

Method and circuit for cascaded pulse width modulation

A power flow controller responsive to power circulation demand for optimizing power transfer is disclosed. When a power flow controller operates at its rated capacity, it can no longer regulate from-bus voltage set-points, line power flow set-points, or both. In such cases, the power flow controller switches to power circulation set-point control without exceeding the rated capacities of the voltage-sourced converters in the power flow controller. Power-voltage (PV) curves associated with voltage stability analysis for maximizing power transfer can be generated and stored for use with a power flow controller operating in automatic power flow control mode.

Power flow controller responsive to power circulation demand for optimizing power transfer

Growing community of inventors

Sunnyvale, CA, United States of America

Abdel-Aty Edris