Concerns of power quality problems, especially for sensitive loads are well known. The integration of microgrid and renewable energy sources with power converters is propounding this problem. This challenges us to know more about their control techniques so as to optimize their performance, both in terms of time and memory. This paper is concerned to analyze the formulation of three control theories (ISC, IRP, SRF) in terms of computational time and memory, used in control of Active Power Filters to mitigate these problems. This assists in optimizing a given DSP algorithm for APFs and also reducing the overall operational time. A comparative analysis is presented with their Big-O polynomial to comment upon their efficiency in time and memory space. © 2016 IEEE.