With the increasing adoption of renewable energy sources into power grids, the issue of voltage and frequency fluctuation of the network becomes a more critical problem that needs to be resolved urgently. The so-called demand-side management (DSM) of power system provides the opportunity for the prospective grids to intelligently balance the power supply and consumption. As one of the crucial roles of DSM, smart loads are naturally committed to manage the power flow of the network. Other than previous communication-based smart loads, the recently proposed electric springs (ES) provide an opportunity to turn some conventional loads into smart loads without the need for communication. In this paper, a simple voltage and frequency (vandf) control method is applied to such a smart load for tackling the voltage and frequency fluctuations of the power grids. Simulation results reveal that with the proposed v&f control, the smart load can achieve better voltage and frequency regulation performance than that with the conventional control and smart load. Experimental results validating the feasibility of the proposed v&f controller on regulating the voltage amplitude and frequency of the common-coupling point of a power grid are provided.