FSC fixed series compensation for overhead lines up to 800 kV, 100–1400 Mvar
Fixed Series Capacitor (FSC) is a series capacitor compensation installation for long high- and extra-high-voltage AC overhead lines. A capacitor bank of 100–1400 Mvar is connected in series in the line at voltages up to 800 kV. This lets an existing line transmit more power without building a new one.
- Grid class
- < 800 kV
- Bank rating
- 100–1400 Mvar
- Capacitor protection
- metal-oxide varistors (MOV), bypass breaker
- Fast protection
- controlled spark gap, shunting < 1 ms (versions without a gap possible)
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The transmission capacity of a long overhead line is limited by its inductive reactance, which increases voltage drop and transmission angle. Capacitors inserted in the line partly compensate this reactance. According to the equation P = U₁·U₂·sin(δ₁−δ₂)/(X_L−X_C), the transmitted power increases, the voltage at the connection point rises, and the transmission angle, voltage drop and its dependence on load decrease. Static and dynamic grid stability becomes higher. Long lines, where the inductive reactance is especially large, benefit the most.
FSC also influences the distribution of flows between parallel lines. For the operator it is a way to postpone the construction of new lines, which is more expensive, takes longer and is increasingly difficult because of regulatory requirements, public opinion and environmental restrictions. The technology is applicable on both new and existing lines, and in the manufacturer's assessment it remains the most economical option for system operators because the design is simple and proven. The installation takes less space than an additional line of the same transmission capacity, and its construction time is much shorter. The environmental impact is also lower, since no new routes or towers are needed.
The capacitors are protected by metal-oxide varistors (MOV). In case of a fault on the line the installation is shunted by a bypass breaker, and a controlled spark gap shunts the capacitors and varistors in less than 1 ms. If local requirements call for it, the installation is built without a spark gap. The equipment stands on a platform insulated from ground, and the design is suitable for seismic regions. The company manufactures the main components itself and designs each installation for the parameters of a specific grid. The degree of compensation, bank rating and protection settings are calculated for a particular line, taking into account short-circuit currents and operating modes of neighboring lines.
FSC is part of the FACTS portfolio together with controlled series compensation CCSC PLUS, the SVC PLUS STATCOM, mechanically switched capacitor banks MSC/MSCDN and synchronous condensers. An example of implementation is the Hirvisuo series compensation installation in Finland. Typical sites are high-power transmission corridors, long 330–750 kV overhead lines, grids undergoing modernization, and lines for power evacuation from remote wind and solar plants.
Technical specifications
| Grid class | < 800 kV |
|---|---|
| Bank rating | 100–1400 Mvar |
| Capacitor protection | metal-oxide varistors (MOV), bypass breaker |
| Fast protection | controlled spark gap, shunting < 1 ms (versions without a gap possible) |
| Location | on an insulated platform in the line section |
| Seismic withstand | robust design for seismic regions |
Request a price and lead time
FSC fixed series compensation for overhead lines up to 800 kV, 100–1400 Mvar. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8532 10 00 00 |
|---|---|
| HS, 6 digits | 8532 10 |
| CN (EU) | 8532 10 00 |
| HTSUS (USA) | 8532 10 00 00 |
| China customs tariff | 8532 10 00 00 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
For what voltage class are FSC installations built?
FSC installations are intended for grids with voltage up to 800 kV. The capacitor bank rating is from 100 to 1400 Mvar.
How are FSC capacitors protected during a line fault?
The capacitors are protected by metal-oxide varistors and a bypass breaker. A controlled spark gap shunts the bank in less than 1 ms.
Can FSC be installed on an existing line?
Yes, the technology is used on both new and existing overhead lines. The installation is designed for the parameters of a specific grid.
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