Integrated Framework for Development, Emulation, and Testing of High-Level Converter Control Functions for Distributed Generation Sources

Abstract

With the increase in power installed from distributed generation sources (DGS), many problems have appeared following the utilisation of novel topologies and structures. Higher-level controllers for the safe operation of power grids with a high penetration of DGS must be developed. This task becomes difficult as the size and complexity of modern power systems have increased. The development and testing of these systems under strict human supervision controlling each step of the testing procedure is no longer viable. This paper presents a comprehensive integrated platform based on an HIL emulator for the development and testing of electric power systems rich in DGS. Essentially, DGS is considered a controllable black-box system. A detailed calculation of the power references for an arbitrary DGS is shown. The paper also describes the utilisation of enhanced Python scripting which was designed to load all network-related data, start the emulation, collect the data, and generate reports. Furthermore, fully developed controller built-in oscilloscope functionality is introduced. The incorporated oscilloscope facilitates non-intrusive DGS controller data acquisition and analysis, reducing the need for external measurements. The proposed framework was verified by a case study in which a grid topology consisting of 26 nodes was emulated on parallel CHIL infrastructure. Four active and twenty-two passive nodes were instantiated and their reaction to a distribution network grid faults was examined. DGS converter control was executed in external controllers outside of the dedicated HIL environment. All DGSs were governed by different control strategies, regarding maximisation of active/reactive power production, minimisation of the active/reactive power oscillations, adjustable positive/negative components ratio, or without any limitations under voltage disturbances. Real-time experiments confirmed the usefulness and flexibility of the proposed framework concept.

Keywords

• Distributed power generation
• emulation
• hardware-in-the-loop simulation
• power control