The Hilbert Huang Transform (HHT) is a powerful tool for Power Quality (PQ) classifications. One of the main advantages of the HHT is its ability to analyse non-stationary complex waveforms with very good time resolution. However, like other waveform classification techniques, it has difficulty in resolving the instant of sudden changes in the waveform. It has also difficulty with signals that have frequency components close together. This paper summarises the fundamentals of the HHT technique and its application to power quality classifications including its advantages and disadvantages. Two novel techniques to improve the performance of the HHT technique in analysing power quality problems will be proposed. Results from simulations will be provided and discussed.