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Inverter controlled series compensator
| Details |
Inventors: Nelson, Robert J.; Ramey, Donald G.;
Assignee: Westinghouse Electric Corporation (Pittsburgh, PA)
Primary Examiner: Nguyen; Matthew V.
Assistant Examiner:
Attorney, Agent or Firm:
An Inverter-Controller Series Compensator (ICSC) has a reactive impedance element connected in series with the line of an ac transmission system and an inverter connected in parallel with the reactive impedance element to control the voltage across, and therefore the current through, the reactive impedance element to provide a continuously adjustable series reactance for power flow control, series voltage regulation, oscillation damping and stability enhancement, as needed. By providing the inverter with a source/sink of real power, the ICSC is further capable of adjusting series impedance. The reactive impedance element can be either a capacitive element or an inductive element depending upon whether there is a need for capacitive or inductive compensation. |
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DETAILED DESCRIPTION These needs and others are satisfied by the invention which is directed to an inverter-controlled series compensator (ICSC) having a reactive element, either an inductor or capacitor, connected in series with a transmission line and a continuously adjustable inverter in parallel with the reactive element to control the voltage across the reactive element, and, therefore the current flow in order to provide a continuously adjustable series reactance for power flow control, series voltage regulation, oscillation damping, and stability enhancement, as appropriate.
The switching power converter may be interfaced with the power system by a series transformer or directly, and may be single phase, three phase or N-phase, as power system requirements dictate.
The switching power converter may be an inverter having a source or sink of real power or it may be an inverter operated by itself.
If the inverter can interface real power, either with the system such as via a shunt connected ac to dc converter or rectifier, or with an independent source or sink, the ICSC is capable of series impedance control; otherwise it is only capable of series reactance control.
More particularly, the invention is directed to apparatus for providing series compensation in an ac electrical power transmission system having a transmission line carrying an ac current at a selected transmission line voltage and fundamental frequency, said apparatus comprising: a reactive impedance element connected in series in said ac transmission line; switching power converter means generating an alternating voltage at said fundamental frequency with controllable magnitude and controllable phase angle; means connecting said switching power converter means in parallel with said reactive impedance element to impress said alternating voltage across said reactive impedance element and thereby control flow of said current through said transmission line; and control means controlling said controllable magnitude and said controllable phase angle of said alternating voltage to control said current
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Electrical and Wave 
