30-MJ superconducting magnetic energy storage (SMES) unit for stabilizing an electric transmission system

Abstract

Electric power systems that have major loads and generation centers separated by large distances may experience low-frequency power oscillations. This type of oscillation has occurred on the Pacific AC Intertie that connects southern California and the Pacific Northwest. A separate, almost parallel, dc-transmission line also connects these areas. The Bonneville Power Administration, which operates this transmission system, has overcome the instability by controlling the power transmitted on the dc-transmission line. A 30-MJ (8.4-kwh) superconducting magnetic energy storage unit with a 10-MW converter could also provide damping for this instability. The conceptual design of the 30-MJ coil and the cryogenic and electrical components of the system are described. The system is to operate at a maximum current of 5 kA and will modulate the AC Intertie at 0.35 Hz. Discharge will be controlled to retain a minimum stored energy of 20 MJ to limit cyclic strains in the coil and ac losses in the conductor. The conductor will be made of multistrand-copper and copper-matrix, multifilament NbTi superconducting wires on a stainless steel mandrel.

Robustness of damping control implemented by Energy Storage Systems installed in power systems

“…Superconducting Magnetic Energy Storage (SMES), Battery Energy Storage System (BESS), Flywheel Energy Storage (FES), and Pumped Storage Hydro Power Station (PSHPS) are commonly used ESS in power system stability control [1][2][3]. To investigate and validate the capability of those ESS in one of the important applications of stability control -to suppress power system oscillations, various tools and techniques have been used, such as the modal analysis based on linearized models for SMES [4][5][6][7][8], modeling power electronics into power systems for BESS [9][10][11], simulation and laboratory experiment for FES [12] as well as application of advanced control theory for BESS [13,14]. Research results obtained so far indicate that ESS control can significantly enhance power system stability by damping system oscillations effectively, which has been confirmed by field applications of BESS and PSHPS reported in [15] and [16] respectively.…”

Design and Operation of the 30 MJ Superconducting Magnetic Storage System on the Bonneville Power Administration Bus

“…The predicted power 10US, P, in the 30 14Jcoil when modulated einusoidally q t frequency f and peak modulation power Pm la given by P -36(;) + 16 (~)2(~f# (1) I with P in W, Pm in MU, f in EZ. The coefficients in equation (1) are derived from laboratory~asurementrns on pre-production samples of 30 W conductor.…”

“…The coefficients in equation (1) are derived from laboratory~asurementrns on pre-production samples of 30 W conductor. me first term on the RES, representing hyatereaiie 10S8, is based on meaaured critical current M field curves, although such calculations were 20Z lower than d.rect measurements on the superconducting wire.…”

Power System Voltage Stabilizer Using LC Resonance Circuit With Superconducting Coil and Capacitor

“…In such a background, the development of a reliable voltage stabilizer restraining instantaneous voltage sag is strongly required. So far, a number of researches on this problem using superconducting technique have been tried [1]- [4].…”