This paper presented the performance and analysis of multi-pulse electronic load controller (ELC) for isolated asynchronous generator (IAG) with improved power quality. Conventional electronic load controller based on six pulse uncontrolled rectifier contains large content of harmonics which distorted the generator terminal voltage, generator terminal current, capacitor bank current, rectifier current. To improve the performance of system, multi-pulse uncontrolled rectifier bridge with the zigzag phase-shifting transformer is proposed. The proposed ELC based system is configure with the 12 pulse, 24 pulse and 36 pulse ac- dc converter to reduce the harmonic contents of the designed system to meet the requirement as prescribed by the IEEE standard 519. The THD (Total Harmonic Distortion) is evaluated based on FFT (Fast Fourier Transformation) analysis of these waveforms. Proposed system is developed in MATLAB/SIMULINK environment and power system toolboxes.