Novel method for estimation of PQ indices in microgrids

Due to evolution in the power system, the emergence of smaller generating systems such as micro turbines, Wind Turbines, Solar PV system, etc., have opened new opportunities for onsite power generation which is located at user´s site called Distributed Energy Resources (DER). The DER consists of generators, energy storage, load control and advanced power electronics interfaces between bulk power providers and the generators. The significant potential of DER to meet customers need and utilities independently can be captured by organizing these resources into Microgrid. The establishment of Microgrid systems within the network appears as an alternative that may be used during blackouts when some areas like electrical transport system financing activities, academic institutes, industries, health centres with no emergencies some communication systems, fail to operate. With the ever increasing use of Power Electronics devices, Power Quality has become a major concern for utility operators as well as consumers. Power Quality mainly affect due to disturbances like voltage sag, swell, transients (oscillatory and impulsive) momentary interruptions, harmonics, flicker etc. This necessitates monitoring these disturbances continuously so that it can be corrected almost instantly. The different methods for power quality indices estimation are RLS, LMS, LES, FFT, Kalman Filter, Wavelet Transform, etc. In this paper very simple and faster, Modified Recursive Gauss Newton (MRGN) algorithm for power Quality estimation is used. This estimation is done for the output terminals of the DG and it further fed to the Dynamic Voltage Restorer (DVR), a series compensating device for power quality improvement in terms of Voltage Sag, Swell and Harmonics during supply disturbances.