Systems with High Level Integration of Renewable Generation Units

Purpose

The aim of the project is to develop the operation and regulation strategies for distribution systems with high level of renewable energy based (REB) dispersed generation (DG) units in normal operation to secure the required frequency, voltage and power quality.

 

Content

The operation and control of the traditional power system are conducted in a vertical hierarchy. However, the vertically structured and operated system is changing due to the large integration of diverse dispersed generation (DG) units to the distribution network, including both renewable and non-renewable sources such as wind turbines (WTs), photovoltaic (PV) generators, small hydro, fuel cells and gas/steam powered Combined Heat and Power (CHP) stations. Consequently, the power system will be horizontally structured. In order to operate and control such a different power system, a great number of challenges are presented, e.g. a complicated load flow pattern, different characteristics introduced by the power electronic interface as well as the stochastic nature of some of the primary sources, such as wind speed and radiation. Power system analysis using a probabilistic approach has attracted many attentions. However, these analyses are mostly focused on traditional power systems. The probabilistic analysis of REB DG units, especially the impacts of the stochastic of renewable sources on the system network, has not been found to be detailed in the literature. The methodologies of the research work will start with model development. The probabilistic models of DG units with their associated prime sources and other power system components will be used for normal operation and developed based on the previous deterministic modeling work conducted at the Institute of Energy Technology at Aalborg University. Then, the operation and control characteristics of power electronic interfaced REB DG units will be studied. The derived characteristics will be represented in the model. Such models will be integrated to construct a probabilistic system model. Thereafter, the impacts of integrating REB DG units on the system model will be studied in terms of frequency and voltage control, power quality, and capacity limitation of the integration. Finally, the appropriate operation and control strategies for normal operation situations, taking into consideration the various constraints, will be derived and designed on the basis of the Danish power system to achieve high availability and good power quality. Currently, the project is at the beginning stage, which is devoted to measurement data collection and probabilistic modeling of DG units and loads.