Supercapacitor energy storage system for pumping units

Addressing issues such as difficulty in maintaining complete balance of the balance block in the pumping unit system, grid pollution caused by reverse power generation, heating caused by braking, and energy waste, a comprehensive solution of energy storage system for pumping units based on super capacitor was proposed. Design of specific functional modules such as super capacitor modules, fast charge and discharge units, reverse power generation status identification systems as well as protection systems were innovated, and the field trial of energy storage system for pumping units was conducted in three wells in Shengli Oilfield. When super capacitors are determined as the preferred storage medium for the energy storage system used by oil pumping units, the field application shows the capacity remains at 251 F with a capacity retention rate of 86.55% after 170 000 cycles, meeting the demands for the energy storage system used by oil pumping units. During charging, ZVS phase-shift technology was employed, ensuring that power devices operate at a zero-voltage turn-on state, minimizing power losses. Following the addition of the energy storage system, the power consumption of the oil pumping units significantly decreased. Notably, the power savings for Pump No. 3 reached 27.0%, translating to a daily energy saving of 27.11 kW · h and an annual cost saving of RMB 6 829. This research plays significant role in making full use of energy reversely generated by the pumping unit and power saving, which provides valuable experience for the subsequent promotion and application of pumping unit energy-saving technologies.