Aspects of the present invention relate to a method for controlling one or more wind turbine generators. The method comprises: monitoring an electrical parameter of a power network to which the wind turbine generators are connected with respect to a deadband for the electrical parameter; and determining that the monitored electrical parameter is deviating outside of the deadband. In response to determining that the electrical parameter is deviating outside of the deadband, the method comprises: quantifying a severity of the deviation; and selectively implementing a parameter control mode when the quantified severity of the deviation is at or above a threshold level. In the parameter control mode, one or more power set points are determined based on the value of the electrical parameter and are dispatched to control the wind turbine generators.