According to Peter Jones of ABB Power Systems, the growing move to renewables, “Brings a whole basket of technical problems, but its all solvable”.
Speaking to a group of journalists in London, he explained that because much of the wind and wave power is going to be generated on and off the coast of Scotland, and in other remote locations, there are going to have to be very long transmission paths to where it is going to be used.
Long transmission lines suffer from two problems that can result in system instability and power outages. One is, “Voltage stability” and the other is “Angular stability”. He explained that the voltage stability problem is due to the need to provide power to provide the magnetic field energy round the cables, which is associated with their inductance. He explained that, “Its like a tank of water that has to be held at a certain level”. The angular stability problem, he said, “Is like transmitting power along a long shaft”.
ABB’s solution is to use Static VAR Compensators, (SVCs). These are massive banks of individually switched capacitors in conjunction with thyristor controlled inductors. By using the thyristors to switch the reactors and capacitors in or out of the circuit, it is possible to provide a continuously variable MVAR (Mega Volt Amps Reactive) injection or absorption to the electrical network. Jones added that, “It’s the responsibility of the generators to do this”.
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