Smart Digital Current Simulator (SDCS) for BESS Power Management

Commercial Battery Energy Storage Systems (BESS) are equipped with a standard control unit with simplified logic able to reduce the impact of the power system on the electric grid. The standard control is locked in a closed environment without any chance to modify the logic. The control unit receives signals from current sensors located at the entrance point of the power system. The paper presents a proposal of innovative device called Smart Digital Current Simulator (SDCS) as a substitute of those current sensors, aiming to generate a sinusoidal signal that falsifies the real induced current inside current sensor's windings by house power leads, in order to fool the control unit to inject or withdraw the desired electric power from or to our electric system. The paper shows a prototype of the suggested SDCS completed of the open sources Node-Red server, MQTT broker and Home Assistant Container. The SDCS communicates through MQTT (Mosquitto) and can be managed by a user-friendly GUI (Graphic User Interface) with open logics to manage a user-desired charge and discharge. The SDCS permits to comply Demand Side Management and Demand Response strategies, otherwise not possible. Moreover, it is useful to buy energy when the price of electricity is below a specific threshold or to prefer the BESS power instead of the grid power when the price of electricity is above a specific threshold. That may be another application to perform a peak shaving to keep the withdrawal power constant from the grid.