posted on 2014-12-15, 10:36authored byDavid Anthony. Parker
This report describes the work undertaken to develop a real-time dynamic simulator for a renewable energy conversion system, focusing on wind energy converter systems (WECS). An assessment of exiting simulators including hardware-in-the-loop simulation (HILS) has shown that there is a need for a hardware simulator with a comprehensive description of WECS aerodynamics.;The report reviews the modelling of WECS and establishes models for both the aerodynamics and drive train dynamics. Once the models have been established the hardware and software used for the simulator are introduced. The hardware consists of a DC drive controlling a DC motor, which acts as a prime mover and provides a shaft torque for a grid connected induction generator. The software used to model the WECS 'front end' and to provide a torque demand, via a serial communications link for the DC drive, is the Matlab/Simulink environment with the Real-Time Workshop.;A model of a 45kW WECS is developed from specifications provided, and implemented in Simulink as a software-only design. Verification of the model is obtained by comparing the performance of the simulation with measured site data.;Following the verification of the software-only model, the effects of including hardware in the simulation are modelled and assessed. Additionally, the effects of including the DC motor in the hardware test-bed are investigated and compensated for prior to the assessment of HILS.;The results of the HILS show that the simulator compares favourably with the measured site data and meets the objectives of the project brief. There are, however, some discrepancies between the simulated results and measured site data at high frequencies due to noise in the system. An alternative method of communication, between the PC and drive using a data acquisition card, is introduced to improve the response. The resulting simulations, with the card used for communications, show that the low to mid-frequency response is improved.