DC Bus Voltage Control for Renewable Energy Distributed Power Systems

In English His paper addresses voltage control of distributed DC power systems. Especially the dynamic properties of load source interactions are highlighted. They are interesting since the sources are considered weak for a distributed power system. This is illustrated with simulations where the power is fed from wind turbines only, and still constant power loads are controlled at the same time as the DC bus voltage level. The wind power generators are modeled as permanent magnet synchronous machines. The controller needed for the machines, including position estimation and field weakening, is discussed. To control the DC bus voltage, more power than consumed by the loads must be supplied to the wind turbines and the excess power removed by pitch angle control. Pitch angle control is a comparably slow process and therefore the DC bus voltage controller must handle the transient power distribution.