A novel indirect DC-link voltage control scheme is presented for two-stage three-phase grid-connected inverter， which is applicable to connecting renewable energy generation system to the power grid. Different from the traditional direct DC-link voltage control scheme， the method proposed is realized by calculating and controlling the amplitude of sinusoidal modulation signals. This eliminates the DC-link voltage sensor and makes the whole system more reliable and less expensive. After analyzing the operational principle under balanced operation condition， the indirect DC-link voltage control method has then been successfully extended to implement in three-phase voltage unbalance condition. MATLAB simulations prove the validity of the control method proposed.