Enhancing Grid Stability through Advanced Power Plant Performance Testing - Design and Development of Inverter-Based Testing Equipment for Comprehensive Power Plant Performance Assessment

Abstract

Abstract In the shift to renewable energy sources, traditional electricity production is disrupted, posing new demands to maintain grid stability. Regulations regarding increased requirements for frequency regulation have therefore been adopted in Europe. To ensure compliance with these regulations, extensive testing of power generation facilities is needed. The project has contributed to further development of testing equipment aimed at testing power plant performance in regulating its output power given frequency deviations in the power system. Power plants are fed back from the power system via transducers to be able to control appropriate output signal. In power plants, there are various types of transducers for the conversion of various electrical quantities. Modern transducers can transmit all electrical quantities, so-called multi-transducers. The project’s goal has been to make the existing testing equipment compatible with all the quantities that the power plant transducers can provide. To enable compatibility with voltage and current, two inverter with a mutual control unit have been designed. The test equipment replaces the feedback loop from the power generating system and creates artificial test signals to evaluate the power plant’s response to various changes in the power system. The testing equipment’s signals imitate the characteristics of the power system in terms of voltage and current with corresponding phase shifts in three phases. In addition, a study of what impact the transducer itself has on the closed loop system has been conducted. The study has been carried out in the simulation program Simulink, where the transducer has been modelled as either a time delay or a low-pass filter, as well as the combination of the two, in models of hydropower plants and battery storage. Simulated results show good performance in terms of accuracy and response to setting changes. Construction of a physical prototype has begun, where the inverter controlling the product’s voltage has shown promising results. The inverter intended to control the product’s current output requires further work. The study concerning the performance of the transducer shows little or no impact on the two models.