PCS-9571 fault current limiter (FCL) based on a fast switch
The PCS-9571 is a fault current limiter (FCL) for high-voltage AC networks with a switch opening time below 5 ms. It is installed where the growth of generating capacity and network density raises short-circuit currents above the breaking capacity of circuit breakers. During a short circuit it inserts a current-limiting reactor into the circuit within a few milliseconds.
- Principle
- a fast circuit breaker bypasses the current-limiting reactor; during a short circuit it opens and inserts the reactor
- Opening time of the fast breaker
- below 5 ms
- Closing time
- below 20 ms
- Mechanical life
- over 2000 operations
Price, availability and lead time on request. We help with analogue selection, customs clearance and delivery.
Description
The device consists of a fast switch, a high-speed measurement and fault recognition system, and a power supply with insulation at high potential. Here the manufacturer used its own experience in measurement, protection and control in high-voltage networks, as well as in the operation of HVDC converter valves and hybrid DC breakers. The primary equipment is limited to the switch and the reactor, so the installation is compact.
In normal operation the switch bypasses the current-limiting reactor, the impedance of the limiter is very small, and it does not affect the network. During a short circuit the control system recognizes the fault by the instantaneous value of the current and its rate of rise, opens the switch and transfers the current to the reactor, where it falls to the permissible level. There are no transient oscillations or overvoltages. The limiter returns to normal mode by itself, and a soft closing function excludes a repeated shock if the short circuit turns out to be non-permanent.
The switch has a repulsion-type electromagnetic actuator. The actuator and the contact gap are at the same high potential, no insulation between them is required, and speed and mechanical life increase. The actuator is supplied through an isolating transformer, so operations are possible also on a de-energized line. The rated opening time is below 5 ms, closing time below 20 ms, and mechanical life over 2000 operations. For higher voltages the required number of gaps are connected in series.
The reactor is air-core. The overall thermal class of its insulation corresponds to class F, and the inter-turn insulation to class H. The reactor stands on supporting porcelain insulators of non-magnetic material, and its impedance is selected for the required limiting level taking into account electrodynamic and thermal withstand. For measurement the manufacturer offers electronic or conventional electromagnetic current transformers with a sampling rate above 10 kHz, high linearity and no residual magnetization.
The control system inserts and removes the limiter automatically, and current and time settings are adjustable. Interlocks, manual control, self-supervision, fault recording and signal transmission to the HMI are provided. The configuration of a particular FCL is chosen on the basis of system analysis of regimes, overvoltages and relay protection.
Technical specifications
| Principle | a fast circuit breaker bypasses the current-limiting reactor; during a short circuit it opens and inserts the reactor |
|---|---|
| Opening time of the fast breaker | below 5 ms |
| Closing time | below 20 ms |
| Mechanical life | over 2000 operations |
| Actuator | electromagnetic repulsion-type, at high potential, supplied through an isolating transformer |
| Reactor | air-core, thermal class F (inter-turn insulation H) |
| Measurement | electronic or electromagnetic CT, sampling rate above 10 kHz |
| Voltage extension | series connection of several gaps |
Request a price and lead time
PCS-9571 fault current limiter (FCL) based on a fast switch. We reply within one business day.
Or email sales@usk.ua or call 044 339-50-20.
Customs codes
| UKTZED (Ukraine) | 8535 90 00 00 |
|---|---|
| HS, 6 digits | 8535 90 |
| CN (EU) | 8535 90 00 |
| HTSUS (USA) | 8535 90 80 80 |
| China customs tariff | 8535 90 00 90 |
Codes are for reference: the final code is determined at declaration for the specific model.
Questions and answers
How quickly does the PCS-9571 limit the short-circuit current?
The rated opening time of the fast switch is below 5 ms, after which the current flows through the reactor. The closing time is below 20 ms.
What is the mechanical life of the switch?
Over 2000 operations. The actuator is electromagnetic, repulsion-type, and is at the same potential as the contact gap.
How is the limiter applied at higher voltage classes?
For higher voltages the required number of switch gaps are connected in series. The reactor impedance is selected for the required level of current limiting.
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