Power Flow Controller (PFC)

Applications
PFC

Issues--VAR Support

PFC Solution

Flicker from Electric Arc Furnaces(EAF) & Welders

Click here more information on flicker correction (PDF)

Voltage Flicker is caused by lack of VARS which are consumed by EAF or welders.

The flicker cannot be tolerated by other customers of the Utility.

Utilities insist on correcting problem at point of common coupling PCC.

Active VAR correction: No capacitors

PFC targets specific frequencies and vectors causing voltage flicker.

Fewer kVAR's required.

Wind Farm Voltage Support

Wind turbines frequently cannot generate sufficient VARS. If VARS are required from the network this can cause voltage sags and system stability problems.

In severe cases turbine generators may be shut down.

Active AVR support as required.

Very fast response keeps wind turbine generators on line.

No capacitors so no risk of resonance.

Compact and cost effective.

Large Motor Starting: rock crushers, car shredders

When a large motor starts it draws high inrush current (VARS). This can cause a voltage sag affecting other customers on the same network.

Active VAR correction delivers VARs as needed to prevent voltage sags occurring.

Dynamic response allows accurate sizing- often less kVARís needed than conventional capacitor solutions.

Applications
PFC with Storage

Issues--kW Support

PFC Solution

Pulse Power

Some customers have peak loads which require very large kW supply but only for a few seconds at a time. At other times they draw much smaller kW from utility.

It is often not economical for utility to increase feeder and/or transformer size just to handle short term peak loads.

The PFC with suitable electrical storage will provide VARs required for pulse power AND also additional kW from storage.

Load will draw maximum available kW from utility line, the extra kW from storage via PFC.

Other loads and utility network will see only limited power variations.

Peak Shaving

Many utilities charge penalties if pre-agreed maximum demand levels even if this only happens once in the billing period.

Penalties can be costly but can be avoided if load can be reduced during peak time or a supplementary power source used for a short period.

The PFC with suitable storage and connected to a power supply (e.g. diesel generator) can provide the excess power needed for a short period to avoid demand penalties.

Power Arbitrage /Wind Farm

Wind farms have variable output during the day depending on winds.

Utility charge peak rate power several times higher than off-peak rates.

If power from wind farm can be stored and sold at peak rates profitability is increased. PFC can be used with a large capacity energy storage device to provide power as needed. The PFC diverts power to storage device during off-peak rates and supplies energy to utility from storage at peak times or if wind is calm.

PFC has available Grid Connect capabilities.