A new vector control method for the delay problem in traditional fictitious method of single-phase grid-connected converter in the condition of voltage signal variation is proposed. Based on the mathematical model of single-phase converter, a fictitious three-phase system is created according to phasor relationship between the phase voltage and line voltage. The real-time performance is significantly improved, which is faster than the instantaneous voltage dq conversion method with 3.33ms delay and the αβ detection method with 5.0 ms delay, respectively. Moreover, a single-phase converter control strategy with reactive power compensation is designed. The MATLAB / Simulink simulation verifies the correctness of the proposed method. And a experiment platform is built with the IGBT module F4-100R12KS4 and 32-bit DSP processor TMS320F2812. The experimental results indicate that the system has real-time reactive power compensation function and excellent performance of dynamic and static response.