This study analyze the use of superconducting magnetic and battery hybrid energy storage to satisfy grid voltage variation. The superconducting magnetic energy storage system (SMES) has been imitate by a high current inductor to consider a system employing both SMES and battery energy storage experimentally.
The design of the laboratory prototype is specify in detail, which consists of a series-connected three phase voltage source inverter used to regulate AC voltage, and two bidirectional DC/DC converters used to control energy storage system charge and discharge. ‘DC bus level signaling’ and ‘voltage droop control’ have been used
to automatically control power from the magnetic energy storage system during short-duration, high power voltage sags, while the battery is used to provide power during longer-term, low power under-voltages. Energy storage system hybridization is shown to be advantageous by reducing battery peak power demand compared with a battery-only system
and by improving long term voltage support capability compared with a SMES-only system. Consequently, the SMES/battery hybrid DVR can support both short term high-power voltage sags and long term undervoltages with naturally reduced superconducting material cost compared with a SMES-based system.
- Dynamic Voltage Restorer (DVR)
- Energy Storage Integration
- Voltage Sag
- Superconducting Magnetic Energy Storage
Figure 1. Hybrid energy storage DVR system configuration
EXPECTED SIMULATION RESULTS:
Figure 2. Hybrid System Experimental results: 0.1s Three phase sag to 35% of nominal voltage. (a) Supply voltages (b) Load voltages (c) DC Link Voltage (d) Battery Current (e) SMES-inductor current.
Figure 3. Battery System Experimental results: 0.1s Three phase sag to 35% of nominal voltage. (a) Supply voltages (b) Load voltages (c) DC Link Voltage (d) Battery Current.
Figure 4. Hybrid System Experimental results: Long-term three phase undervoltage (a) RMS supply phase-voltage. (b) RMS load phase-voltage (c) DC Bus Voltage (d) Battery Current (e) SMES-inductor current.
The work a novel hybrid DVR system topology has been determine experimentally and shown to efficiently provide voltage benefit for short-term sags and long-term under-voltages. A prototype system has been grown which display an effective method of integrate SMES and battery energy storage systems to support a three phase load.
The system has been shown to separately prioritise the use of the short-term energy storage system to support the load during deep, short-term voltage sags and a battery for lower depth, long-term under-voltages. This can have benefits in terms of enhanced voltage support efficiency and reduced costs compared with a SMES-based system.
Additional benefits include reduced battery power rating need and an expected increase in battery life compared with a battery-only system due to reduced battery power cycling and peak discharge power.
- K. Ray, S.R. Mohanty, N. Kishor, and J.P.S. Catalao, “Optimal Feature and Decision Tree-Based Classification of Power Quality Disturbances in Distributed Generation Systems,” Sustainable Energy, IEEE Trans., vol. 5, Sept. 2014, pp. 200-208.
- Novosel, G. Bartok, G. Henneberg, P. Mysore, D. Tziouvaras, and S. Ward, “IEEE PSRC Report on Performance of Relaying During Wide-Area Stressed Conditions,” Power Delivery, IEEE Trans., vol. 25, Jan. 2010, pp. 3-16.
- “IEEE Recommended Practice for Monitoring Electric Power Quality,” in IEEE Std 1159-1995, ed. New York, NY: IEEE Standards Board, 1995, p. i.
- Jothibasu and M.K. Mishra, “A Control Scheme for Storageless DVR Based on Characterization of Voltage Sags,” Power Delivery, IEEE Trans., vol. 29, July 2014, pp. 2261-2269.
- Otomega and T. Van Cutsem, “Undervoltage Load Shedding Using Distributed Controllers,” Power Systems, IEEE Trans., vol. 22, Nov. 2007, pp. 1898-1907.