Takashi Shirasaki

Test Report of a SMES System Connected to a Power System Simulator

A Superconducting Magnetic Energy Storage (SMES) system is capable of rapidly discharging energy, and thus it is effective in cases of load fluctuation and voltage drop.

Life cycle assessment and economical evaluation of superconducting magnetic energy storage systems in a power system

In recent years, the introduction of superconducting magnetic energy storage systems (SMES) into a power system is drawing considerable research effort because of their high efficiency rate and large storage capacity characteristics. In this paper, the introduction of SMES into a power system and its effects on energy and on environmental issues are addressed. The analysis results show that the introduction of SMES can considerably cut down CO2 emissions without increasing the production cost if it substitutes for the operation of thermal plants during peak load period. However, to achieve this, nuclear plants are also needed for charging purposes. Thus, an algorithm to find the best generation mix, subject to CO2 emissions constraints and nuclear plant introduction constraints, is proposed. The inclusion of nuclear plant constraints increases the coal consumption, hence CO2 emissions. Nevertheless, in most of the analyzed cases, the introduction of SMES could attain important cost savings and environmental conservation.

Stabilization of a large‐capacity, long‐distance transmission system by an adjustable‐speed flywheel generator

An adjustable-speed flywheel generator (FWG) can control both active power and reactive power rapidly. We have studied the effect of FWG installation on a large- capacity, long-distance transmission system, especially when the system includes loops. In this paper, we describe the selection of FWG location, the selection of stabilizing control input signal, and the required quantities of FWG. FWG location is selected by a PQ-sensitivity method, calculation of which is simple and permits easy understanding of the effect of both FWGs active and reactive power. As a stabilizing control input signal, we use bus voltage frequency instead of power flow because the flow changes stepwise by opening three-phase single-circuit. Additionally, we clarify the FWG quantities that must be designed, such as FWGs active power and reactive power. We considered FWGs slip to determine the quantity because the capacity of the exciter depends on slip.