This paper evaluates performance of the proposed variable constrained based Least Mean Square (VCLMS) algorithm in terms of convergence, computational time, steady state error and mean square error. The parameters of a power signal containing inter harmonics, sub harmonics and high order harmonics are estimated using the VCLMS algorithm and the results are compared with Least Mean Square (LMS) and Normalized Least Mean Square (NLMS) algorithms for judging the comparative performance of VCLMS in presence of white Gaussian noise with a signal to noise ratio of 20 dB, 30 dB and 40 dB. In a broader sense it can be concluded from the experimental results that VCLMS outperforms the LMS and NLMS algorithms. All the experiments are carried out in MATLAB Simulating environment.