Superconducting Energy Storage Device Research Articles

Nonlinear Control Method of Superconducting Energy Storage considering Voltage Imbalance in Distribution Network

A new nonlinear control approach of superconducting energy storage is devised under the condition of addressing the voltage imbalance of the distribution network in order to obtain more precise control of superconducting energy storage devices (SMEs). The model of the superconducting energy storage device is built on the basis of determining the voltage imbalance signal of the distribution network. Aiming at the situation that the voltage of the device will change at the same time when the structure of the device changes, a nonlinear controller is designed to estimate the discontinuous interference state of the nonlinear controller device and combined with the nonlinear control algorithm to realize the nonlinear control of superconducting energy storage. The simulation test results demonstrate that the design method can accomplish a more accurate signal tracking cut and that switching voltage generation estimation is performed well. It shows that the design method can meet the actual nonlinear control requirements of a superconducting energy storage device.

Experimental investigation of the processes of degradation and transition to the normal state in CC-tapes under the action of current pulses

The study of the behaviour of CC tapes under the action of nonstationary current loads was conducted: a transition to the normal state was observed, as well as processes of CC-tape degradation. The obtained data make it possible to solve the problems associated with the creation of high-speed switching devices based on high-temperature superconductors, intended for functioning in superconducting energy storage devices, energy distribution and transmission systems, current limiters, and new types of transport. In addition to superconducting switches, pulsed current loads can occur in the mentioned above systems due to short-circuit conditions or other factors, and can lead to local heating of HTSC, especially if there is an inhomogenity in the critical current in the CC-tapes. In this work we present the results of a study of non-stationary processes second generation HTS tapes heating under the impulse current loads with amplitudes up to 2.2Ic (77K, self-field). Superconducting tapes with a copper protective layer were used as the samples. The I-V characteristics of the samples were measured under the action of current pulses during cooling in liquid nitrogen. Critical parameters (amplitude, rise time of the transport current) of the current pulses, leading to the degradation of the superconductor were obtained. local current carrying characteristics of CC-tapes investigated using Hall probe magnetometry. The features of the influence of local inhomogeneities in the distribution of the critical current of the tapes on the transition of the superconductor to the normal state are revealed.

초전도 에너지 저장 기술에 대한 고찰

Recently, the power industry has a great interest in the superconducting energy storage device as a way to maximize energy efficiency to cope with global warming. A superconducting energy storage device can archive maximization of electric energy use efficiency by storing in the form of a magnetic field energy or a kinetic energy without loss a large amount of electrical energy at the non-peak load and then converting it again into electric energy at the peak load. Therefore, in this study, such as the concept of the superconducting energy storage technologies, the present state of its research and development and its applications are surveyed and analyzed to establish methodology applying the superconducting energy storage technologies to power system.