Increase in wind- and solar parks complicate grid stability due to their deterministic behaviour. ENTSO-E established requirements for generators for grid connection in Europe. A requirement is to have active- and reactive power control that implements a power setpoint given by the transmission system operator. This thesis describes the design and MATLAB implementation of these controllers in a combined wind- and solar power park module. Reactive power control is designed for two modes, namely reactive power control mode and voltage sub-mode 1. The active power control is designed as a rule based controller with a quadratic distribution of power over generator strings. The reactive power control mode is based on a variable structure PI with feedback and pro-rata distribution of reactive power. A design for voltage-submode 1 has been designed based on droop control, but is not corresponding the requirements of the considered case. The
controllers are implemented in model of a real-life case from the company [Blackened text].