Improving power quality in remote wind energy systems using battery storage

Renewable energy sources have the great advantage of being able to provide power in rural areas whenever available. A main disadvantage of wind energy generation (WEG) is the variation of its output power with the variation of wind speed. Such variation may lead to significant consequences on the power quality. When a critical load is fed from both the infinite grid and a wind farm, such that, it is predominantly fed from the WEG while it is connected to the infinite grid via a much weaker transmission line, variation of wind speed will produce serious voltage fluctuations on the load bus. Such fluctuations could result in losing the load. This paper describes a simple test network presenting a rural critical load which is partially fed from a wind farm in addition to the grid. The effect of wind variation on the power quality is studied. A battery bank is connected to the load bus, and its effect is simulated and discussed. Although expensive, connecting a battery bank to critical loads predominantly fed from a wind farm establishes a significant improvement to power quality.