Reliability analysis is widely used in many industrial fields to predict the remaining life of complex systems by assessing their current health status. This paper deals with one of the best-known techniques for reliability analysis: the reliability block diagram. This method models the reliability of the system based on the system's architecture and the reliability of its components. The work analyses the control system of a 2MW wind turbine, proposing two different reliability models. The first draws on a standard control system architecture. The second introduces a cold standby redundancy architecture for the data acquisition subsystem and a warm standby redundancy architecture for the power supply subsystem. With these configurations, it is possible to improve the system reliability by neglecting some failure modes because one of the branches of the redundant configuration will be either inactive or partially active.