This paper introduces voltage self-regulation of a variable speed single-phase induction ‎generator-based wind energy conversion system (WECS) for stand-alone applications. The ‎idea behind the voltage self-regulation technique proposed in this paper is adjusting the fixed ‎capacitor’s effective value for exciting the single-phase induction generator. This adjustment ‎is performed using an inexpensive Sinusoidal PWM (SPWM) switching circuit to short circuit ‎the capacitor during different periods to make a virtual change of the capacitance value extracted from the fixed capacitor. That optimized fixed capacitor size is firstly determined using harmony search (HS) optimization technique. HS is also used to determine ‎the capacitance value required for voltage self-regulation of single-phase induction ‎generators at different speeds through an optimal PI controller. To test the proposed ‎system’s capability, different changes in the prime mover speed are applied to the rotor of the ‎generator and the system succeeds at regulating the voltage with these speed variations. ‎Moreover, a reduction in the harmonics in the output voltage was attained. The performance ‎is of the HS optimization technique is compare to another optimization technique, particle ‎swarm optimization.‎