The grid code is being applied to wind power by the Chinese State Grid Corporation. "It's not an unmoveable set of strict rules but rather a series of guidelines negotiable with the corporation and distributors," said Morales. With China's 2020 renewables target for wind now at 100 GW, "the code has not arrived a day too soon," she added.
It requires wind turbines to ride-through voltage dips down to 20% of nominal grid voltage, without tripping off line for a period of 625 milliseconds, or absorbing reactive power from the network. It also requests turbines to continue operating for at least ten minutes if frequency falls below 48.5 Hz, or for at least two minutes if it goes to 51 Hz from a nominal frequency of 50 Hz.
The State Grid Corporation also demands that wind farm operators provide simulation models for how wind farms will react in specific network circumstances and wind plant control systems. DigSilent is approved by the corporation as an authorised provider of simulations.