Active power control in a grid connected distributed generation system via time delay method

This paper applies time delay approach to control the active power in a grid connected distributed generation unit under varying load conditions. The control algorithm is developed in time domain; therefore, it is (almost) independent of the frequency and phase of the grid voltage. As a result it does not require frequency measurement, phased locked loop (PLL) system, and dq-transformation which reduces the complexity of the control algorithm. However, it is still possible to control the output voltage, or reactive power, at the common coupling point, independent of the dispatched active power.