Main Function's: 

Absolute production constraint
Absolute production constraint is a controlling function which serves to limit the amount of active power generated by the plant at the point of connection

Power gradient constrain
To prevent disturbances on the network, the power gradient constraint enforces a gradient at which the plant must ramp its active power to the desired set point.

Voltage Control
The voltage control function is mutually exclusive with reactive power control and power factor control and serves to regulate the voltage at the point of connection.

Reactive Power Control
Reactive power control is mutually exclusive with voltage control and power factor control and serves to regulate the reactive power at the point of connection

Power Factor Control
Power factor control is mutually exclusive with reactive power control and voltage control serving to regulate the plant at a constant power factor at the point of connection

Frequency Control
Frequency control as defined in the grid code considers both under frequency and over frequency conditions