Wind power plant secondary system

Conclusions Current Grid Codes of islanded European networks like UK and Ireland already consider the participation of wind power plants in primary frequency control. In this sense, they require wind turbines to be operated not extracting the maximum available power from wind.

This category covers, for instance, wind power plants with rated power above 50 MW in continental Europe, above 10 MW in the UK and above 5 MW in Ireland. These wind power plants must be equipped with a power control system for frequency response.

Minimum active power regulation levels for primary, secondary and high frequency response capabilities (i.e. primary reserves activation) for wind power plants in the event of a system frequency deviation of 0.5 Hz according to UK Grid Code . As shown, the change in the generation level depends on the actual loading of the unit.

In order to maintain system frequency stability in a network with an increasing share of wind power, wind turbines will have to take on more and more tasks of conventional power plants related to frequency control.

The sequence, duration, ramp rate and proportion of additional power provision through primary and secondary frequency responses are determined between wind farms and conventional power plants according to system requirements and targeted capital and operating costs.

Each wind power plant (both onshore and offshore) with a registered capacity over 50 MW must be capable of participating in frequency control by continuously adjusting its active power output. This active power control can be performed by applying two operating modes, the so-called frequency sensitive mode and limited frequency sensitive mode.