Any type of generators installed in a weak grid area could harmfully influence the grid with the following effects such as:
power surges produced by the sudden starting or stopping of wind turbines can trip the protection equipment’s in the grid causing black-outs.
short-lived fluctuations in the voltage of the grid can be produced by fluctuations in wind speed, and the starting or stopping of individual wind turbines.
If part of the grid containing a generator becomes electrically isolated from the rest of the grid, the phases of the two sections will differ, and potentially large currents will be generated when they are re-connected.
Suitable power system design and grid integration can avoid these problems. For example, the design process must include a thorough study of existing load dynamics and fault levels to ensure that the wind farm does not accidentally trip the network’s of protective devices. Weak grids can be ‘reinforced’ to avoid voltage flickering, and islanding problems can be prevented through appropriate power electronic controllers which monitor the status of the rest of the grid and shut the turbine down in the event of islanding.
Wind farms can also be designed to provide benefits in weak grid areas by improving power quality. For example, modern wind turbines have in-built inverters and power electronics to ensure and maintain a good ‘power factor’ of the grid.
Power factor is a measure of the efficiency of the grid system. A high power factor indicates higher transmission efficiency, which effectively reduces the total amount of power required from generators in the grid to supply a given customer load. In addition to the resulting cost savings, a high power factor can provide environmental benefits where the main source of generation is non-renewable.