Design of a droop control scheme for generation systems without inertia

Abstract

The Clean Energy Research Lab (CERL) in S2-B7C-05 has a three-phase, 400V, 50Hz microgrid testbed to perform power system studies. It comprises a 13.5kVA synchronous generator, 18kVA programmable source, 6kVAR capacitor bank, 5kW PV system, 13.5kW wind simulator, 5kW battery system, 5kW fuel cell, 13.5kW programmable load as well as a 10kW simulated industrial load. The micro-grid operate in either standalone or grid connected mode. In standalone mode, distributed generations such as the synchronous generator and programmable source, determine the frequency and voltage of the micro-grid. The main difference between the synchronous generator and the programmable source is that the synchronous generator has inertia while the programmable source does not. This means that the former has an inherent power-frequency droop where the generator frequency changes according to its power generated. Conversely, the latter does not have the power-frequency droop characteristic since it has no rotating parts. However, the programmable source can be programmed to imitate the power-frequency droop characteristics that the synchronous generator has. As part of the project, the student is required to design and implement a power-frequency droop characteristic on a 18kVA source, using LabVIEW as the main programming tool. The programmed power-frequency droop will be tested and validated on the 18kVA three-phase AC programmable source, using the 13.5kW three-phase programmable load to vary the load level. Provision for load frequency control and parallel operation of the synchronous generator and the programmable source should be made. Student with a strong background in LabVIEW programming and hardware are preferred. The student will work with Dr Eddy Foo and Mr Ashok Krishnan during the course of this project.