Chester
Customer Story | 2 min read
SVC to stabilize an AC system connected to a large HVDC interconnection
An Hitachi Energy Static Var Compensator (SVC) rated at 125 Mvar inductive to 425 Mvar capacitive is operating since 1990 in the 345 kV network of Maine Electric Power Company at Chester, Maine.
The purpose of the SVC is to r einforce the line between Keswick in New Brunswick, Canada, and Orrington in the New England network, to allow an import of 700 MW to New England along this line, with simultaneous import of 2.000 MW on the Québec-New England Phase II HVDC system (also supplied by Hitachi Energy). The SVC is necessary in or der to meet stability requirements for the New England system for cases involving disturbances on the Phase II HVDC inter connection.
The primary task for the SVC is to pr ovide fast-acting voltage support for the Keswick-Orrington AC tie line following major disturbances on the Phase II HVDC inter connection. In addition, control features such as Supplementary Modulation Control and Undervoltage Strategies are available.
The Supplementary Modulation Control enhances the SVC speed of response and provides damping of dynamic power oscillations on the New Brunswick-New England tie line following system disturbances.
| Main data | |
|---|---|
| System | SVC |
| Commissioning year | 1990 |
| Controlled voltage | 345 kV |
| SVC rating | 125 Mvar inductive to 425 Mvar capacitive |
| Control system | Fully reduntant, three-phase voltage control by means of a voltage regulator. Regulator functions include Supplementary Modulation Control, strategy selection and gain supervision. |
| Thyristor valve | Water cooled three-phase thyristor valves with magnetic firing. |