This application describes examples of a photovoltaic energy storage system including an inverter and an energy storage device. In one example, an input end of the inverter is connected to a direct current bus. An output end of the inverter is connected to an alternating current power grid. The energy storage device is connected to the direct current bus. The inverter is configured to send high-voltage ride-through information to the energy storage device when a high-voltage ride-through occurs in the alternating current power grid. The energy storage device is configured to: when the high-voltage ride-through information is received, adjust an output voltage reference value to maintain a discharging working state if the energy storage device is in the discharging working state, or adjust a charging power reference value to maintain a charging working state if the energy storage device is in the charging working state.