Wavelet Transform for Extraction of Current Reference under Noisy Voltage Condition

In the previous chapters, instantaneous p-q theory was used for reference current extraction. This approach has fast response and the computational time required is also small. But, its performance under noisy voltage condition is found to be not satisfactory. In this chapter, a frequency domain based method is proposed for reference current extraction which is suitable for noisy voltage condition. The proposed approach is based on wavelet transform. The fundamental of wavelet transform and Multi Resolution Analysis (MRA) for extracting the fundamental component of current from distorted load current are presented in this chapter. A fuzzy logic controller is applied to maintain the constant voltage across the capacitor by minimizing the error between the capacitor voltage and the reference voltage as presented in the previous chapter.