The objective of this paper is to propose a simple structure for reactive power control (RPC) of AC Photovoltaic (AC PV) modules. With the proposed structure, a cost-effective microcontroller can be adopted to achieve an effective reactive power control in order to support the grid voltage within acceptable bounds by absorbing or supplying reactive power. Moreover, the sliding mode control (SMC) is adopted to enhance the current control's dynamic response and reduce the current harmonic distortion. Comprehensive simulation of an AC PV module connected to grid using PSIM software with different operation modes are used to demonstrate the control strategy. The results from the simulation show that the proposal can provide good reactive power control for the AC PV modules.