Power system for the airport generates a large number of reactive power and affects power safety.In this paper

the generation mechanism of reactive power in the airport is analyzed

its circuit model and power factor are analyzed so to set up the calculation model of SVG nominal value. In the Matalab/Simulink environment

a cascade system with each 5 H-bridge per phase is constructed. The control strategy with combination of phase-shifted carrier control with single-frequency modulation control is adopted to design the in-phase voltage and inter-phase voltage balancer to achieve inter-phase voltage balance by way of fine tuning the phase of three-phase modulation wave. Both the static and dynamic effect of the system is simulated respectively and the system can achieve reactive power compensation and harmonic suppression.The power factor is improved up to 0.98 with good compensation accuracy and without over compensation and under compensation and the satisfactory reactive power compensation and harmonic suppression result are reached.