I have used two microcontrollers for this project. One is to measure the time difference between the zero crossing points of voltage and line current. The second one is to generate three phase pulse trains to fire three phase AC voltage controller. A star connected capacitor bank is used as a reactive power source. Depending on the time gap (phase angle difference), the capacitors are charged at the controlled rate.
Zero Crossing Detectors (ZCD) for voltage and line currents
The ports of Thyristor controlled capcitor
