The unit improves the quality of electricity produced by wind stations using continuously variable control through high-power transistors. This improves voltage control and stability, and facilitates grid connection of variable energy sources such as offshore wind farms. The units come pre-tested in standardised modular sizes and can provide leading or lagging reactive power in packages with ratings of 25, 35 and 50 mega volt amps reactive (MVAr). The voltage waveform produced, says Siemens, is nearly sinusoidal, so it can dispense with lower frequency harmonic filters to deliver high-quality power to the grid. It can also provide dynamic voltage support during and after system faults, a growing demand from turbines as their output displaces conventional grid generation, which, as a result, can no longer give the support required. The unit can also be used in industrial systems for reactive power and flicker compensation in a power range up to 100 MVAr.