The static apparatus using the electric power conversion and control supports our life base in the electric power energy field. As the research investigation field, an environment friendly nonflammability and a flame resisting transformer technology, a capacitor technology for the deterioration prevention, an environmental application and an advanced high current technology, an electromagnetic numerical analysis technology in the design of the equipment, fault current limiter technology are investigated actively now. In this explanation, the new development of static apprataus technology is described. The static apprataus is developed in a high level in our country. The problem in this explanation will be expected to be overcomed soon.

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In this paper, we theoretically compared the fundamental characteristics of fault current limiter (FCL) with high Tc superconductor (HTS) and two coaxial air core coils based on steady state analysis. Two types of FCL are possible. One of them is parallel type and the other one is transformer type. The parallel type can be divided into two types according to the combination of the winding direction of coils. That is there are two cases that the coils are wound so that the magnetic fluxes induced by coils reduce and increase each other. In this paper, we called them parallel type 1 and 2, respectively. There is no significant difference in the HTS volume required to satisfy both of the specified limiting impedance Z_FCL and initial current I_ini in limiting operation among those three FCL's although the HTS in each type of FCL has different length and cross-sectional area. In the cases of those FCL's, we can improve the current limiting performance by arranging the HTS in the coils and applying the magnetic flux to the HTS in the limiting operation. The magnitudes of the magnetic flux density are almost the same. From the viewpoint of the FCL impedance in normal operation, parallel type 1 has the most desirable structure. On the other hand, transformer type is the best to eliminate the magnetic flux applied to the HTS in the normal operation.

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The magnetic fields in nonlinear anisotropic magnetic materials were analyzed by using the Finite Element Method (FEM). The measured data was directly used in the computation without a complicateded smoothing. The resultant asymmetric linear equations were solved by using the ILUBiCGStab method without symmetrization or the ICCG method with symmetrization. The magnetic flux distributions in a ring core model showed the characteristic patterns according to the non-oriented, grain-oriented and doubly-oriented magnetic properties. The good convergence of the Newton-Raphson nonlinear iteration was attained by the iterative solvers without special techniques for the smoothing.

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We have proposed a flat type of the superconducting fault current limiter (FCL) which is a modified version of a magnetic shielding type of the fault current limiter. The new FCL basically consists of a spiral coil and a doughnut-like form high Tc superconductor (HTS) plate, each of which works as a primary winding and a secondary one-turn winding, respectively. The FCL modules can be easily built up to make a large scale FCL. This simple construction may enable us to reduce the manufacturing costs. Small modules of the flat type FCL were made with Bi2223 bulk plate and the normal and limiting impedance due to a normal load current and fault excess current were measured. It was confirmed from experiments and magnetic field analyses that the ratio of the limiting impedance to the normal one was improved by using the iron core. Although the relatively low impedance ratio was derived in our experiments, a magnetic field analysis sugested that the high impedance ratio in order of 10³ might be realized by completely covering the spiral coil and HTS plate with the high permiability material such as an iron.

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An SVC is proposed as a reactive power compensation device to suppress the rise in the customer voltage due to the photovoltaic power generation systems. The SVC produces a reactive power by controlling a thyristor. The effect of the SVC on the rise in the customer voltage has been investigated. Calculation results show that installing an SVC in the low voltage side is more effective for suppressing the rise in the customer voltage compared to the one located in the high voltage side. As far as the calculation conditions are concerned, it is found that the rated capacity of the SVC needed to maintain the customer voltage within ±101 6V is over ±11.1kVA. The slope reactance required to suppress the customer voltage lower than 107V is found to be under 1.28%.

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Nomex^® brand paper has been used as wire wrapping insulation material of main transformers of Shinkansen Train Series 100 with silicone oil. After approximately 12-13 years service, 8 transformers of Series 100 were sampled to evaluate degradation of Nomex^® brand paper in terms of tensile strength and intrinsic viscosity. All data were compared with initial data. The result of less degradation shows Nomex^® has good thermal stability in silicone oil in the main transformer of Shinkansen Train which were used in very severe condition.

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When a reduction of the waste and dissolution of the iron are carried out by using a high temperature medium, the radiant power emitted from the medium should be suppressed. On the contrary, it is useful for lighting and treatment of hazardous wastes because it has a highly intense radiant energy. In this paper, we tried to calculate the number density and radiant power density under consideration of atmospheric high temperature pure argon (Ar) which is frequently used for a plasma arc to know the basic theory of radiant power density for the development of the plasma treatment by using radiant power. Considering kinds of particles: ArI˜ArIV and e, temperature domain: 1,000K˜30,000K and wavelength domain: 200nm˜1,000nm, and Biberman factor: changeable in wavelength, we calculated the line and continuum radiant power density as ingredients of the radiant power, and mentioned the above characteristics in every temperature, particle and wavelength range. As a result, a dominant wavelength area became ultraviolet to visibile by making Biberman factor change.

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The torch plasma arc has useful characteristics of high energy and high current. And the mode of torch plasma arc can be flexible, even if the arcs is exposed to the lateral gas. In this paper, we measured the input power, heat power, and heat efficiency of the torch plasma arc to the anode in order to know the current effect on the anode attachment of plasma torch arc with the high lateral air velocity, varying from 0 to 80m/s at the plasma Ar flow rate of 12slm. As a result, the input power increases with lateral gas velocity such as about 8,000W to 16,000W and the heat efficiency decreases with the lateral gas velocity such as about 50% to 25% at the current I = 150A and appearance plasma length L_a = 1cm. These results could be applied to providing the electrical power from the ground to high-speed mobiles, v.v., and to reducing an anode surface erosion by the anode spot movement.

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Cathode spots of a low pressure arc can remove the oxide layer and evaporate impurities on the metal surface. The removal of the oxide layer by using the cathode spots in the low pressure is expected to solve the serious problems of the chemical and mechanical cleaning methods. The phenomena of the cathode spots in the low pressure for pre-treatment of Atmospheric Pressure Plasma Spray (APPS) have been investigated. In this paper, the surface shape of oxide work pieces was treated by using the cathode spots in the low pressure arc then compared with the grit-blasted surface. As a result, it is possible to improve the bonding strength of the spray deposit by making arithmetical mean height R_a large and average length of outline curve element R_sm small. Cathode spots of a low-pressure arc can be used for pre-treatment of APPS as the alternative technology of the blast. it is possible to obtain R_a larger an R_sm smaller than the blast only by cathode spots after the blast. But the treatment must be restricted not to destroy projection ones which were formed with melting.

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In this paper, the risk of coming across flow neck in electric power systems is considered, and the computational example on expenses required in order to control the risk is shown. Total fuel cost increases by setting margin which control the risk. This cost is necessary cost for the risk hedge. The uncertainty of load demand is assumed to be normal distribution. Then charge of the line flow which is calculated from changes of each load demand is assumed by using sensitivity coefficient. The risk of arising uncertainty of load line flow is shown. In order to control this risk, a margin is introduced, and the relation between this margin and the incremental fuel cost is calculated. This calculation technique can estimate expenses required in order to control the risk arising from uncertainty of load.

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In long distribution system, Step Voltage Regulators (SVRs) are installed to regulate the system voltage. There are some papers about finding optimal placements of SVRs in the system. However, there is not analytic method in the view of the voltage margin i.e. optimal on the system voltage.
The Authors propose a method finding the placement of a SVR so that the voltage margin from the upper (or lower) voltage limit is the largest in heavy load.
In order to deal with sets of loads that are dispersed on distribution line completely, the authors have drawn differential equation of complex power and one of voltage drop which are expressed by function of distance from a substation by transforming. The voltage profile is given as the polynomial expression by solving the voltage equation if load distribution is trapezoid type. The method finding optimal placement of a SVR is distinguished in three modes by three different voltage profiles. One is the case of that ratio of transformation of a SVR is small and the system length is short. Another is the case of that ratio of transformation of a SVR is large and the system length is short. The other is the case of that the ratio of transformation of a SVR is large and the system length is long. The optimal placement and the tap position of a SVR are calculated by solving above-mentioned equations in these three modes.
It has been confirmed that the proposed analytical method is appropriate by a model calculation result.

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In this paper, an efficient method is proposed to deal with short-term load forecasting with the Gaussian Processes. Short-term load forecasting plays a key role to smooth power system operation such as economic load dispatching, unit commitment, etc. Recently, the deregulated and competitive power market increases the degree of uncertainty. As a result, it is more important to obtain better prediction results to save the cost. One of the most important aspects is that power system operator needs the upper and lower bounds of the predicted load to deal with the uncertainty while they require more accurate predicted values. The proposed method is based on the Bayes model in which output is expressed in a distribution rather than a point. To realize the model efficiently, this paper proposes the Gaussian Processes that consists of the Bayes linear model and kernel machine to obtain the distribution of the predicted value. The proposed method is successively applied to real data of daily maximum load forecasting.

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The authors have examined the equivalent circuit of synchronous generator and proposed that the field mutual leakage reactance in rotor circuit (Canay reactance) and the saturation of main flux is desirable. This paper describes the study on load rejection characteristic with proposed equivalent circuit model , using the electromagnetic transients program (ATP-EMTP), and compared the results with the experimental data.

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Deregulation and restructuring of electric power supply business are proceeding all over the world. In many cases, a competitive environment is introduced, where a market to transact electric power is established, and various attempts are done to decrease the price. On the other hand, environmental problems are pointed out in recent years. However, there is a possibility of the environmental deterioration by cost reduction of electric power. In this paper, the RPS (Renewable Portfolio Standard) system is taken up as the solution method of environmental problem under the deregulation of electric power supply business. A RPS model is created by multi-agent theory, where Q-learning is used as a decision-making technique of agent. By using this model, the RPS system is verified for its effectiveness and influence.

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Recently, wind energy conversion system using a Doubly-Fed Synchronous Generator (DFSG) has attracted an interest. This system can control rapidly real and reactive power output independently by secondary AC excitation. Furthermore, since wind turbine can be operated in variable speed, fluctuations of the output due to changing wind speed in short period can be reduced. This paper proposes a new control method for this system to enhance the transient stability of neighboring induction generators in the same wind farm.

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In recent years, a lot of distributed power generation such as photovoltaic and wind power generation are going to be installed in power systems. However, the fluctuation of these generator outputs affects the system frequency. Therefore, introduction of battery system to the power system has been considered in order to level the fluctuation of the total power output of the distributed generation. In the present paper, the authors propose a systematic method to evaluate the appropriate battery storage capacity and the power converter capacity of the battery for the various type of wind power outputs. The minimum required capacity of the battery is determined reasonably from the viewpoints of battery cost and load frequency control system in a power system with a large penetration of wind power generation.

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In an electric power day-ahead market, market prices are not always cleared at marginal cost caused by the strategic bidding of generators. This paper presents the results of day-ahead market simulation that analyzes profits depending upon bidding strategies in an electric power day-ahead market. It is clarified that MCP (Market Clearing Price) is easily managed by only one player and does not easily decline after it has gone up once. Moreover the mutual interference among day-ahead markets, future markets, increase of generators, etc. are also discussed.

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The objective of this work is to discuss the concept of back-to-back interconnection systems with energy storage, especially with a Superconducting Magnetic Energy Storage (SMES) incorporated into a back-to-back DC link. In this case, each converter of the back-to-back system is used as a power conditioning system for the SMES coils. Since the AC/DC converter can be designed independently of the frequency of the power system, a two-way switch is connected to the AC side of each converter. This two-way switch can select the interconnected power systems. By using the two-way switches, this system can provide the stored energy in the SMES system to each interconnected power system through two AC/DC converters. For instance, lower-cost power of each power network can be stored through two converters during the off-peak hours and made available for dispatch to each power network during periods of demand peak. Then this system increases the reliability of electric power networks and enables the economical operations depending on the power demand. This paper describes the unique operations of the back-to-back interconnection with SMES and discusses the optimal SMES configuration for a 300-MW class back-to-back interconnection.

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To develop vacuum circuit breaker (VCB) for higher voltage application, it may be important to understand generating mechanism and its influence of non-sustained disruptive discharges (NSDD) to the systems. So, we carried out the tests using equivalent testing circuit and observed the contacts after testing, For the test, by using commercial vacuum circuit interrupters, AC voltages of 50Hz was applied between contacts for 4 seconds after current interruption, and measured generating frequencies of NSDD vs. the voltages and vs. currents. Typical contact material used in the commercial switching equipment, such as AgWC, CuW, CuCr were tested and compared. Then CuCr's of different composition and manufacturing process are investigated. And CuCr-50 (manufactured by melting process) showed the best performance in all tests. We point out that surface condition may affect the generation of NSDD and also conditioning effect is very important.

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Silicone Liquid is less-flammable and has less environmental pollution compared with mineral oil. Applicability of 20cSt Silicone Liquid to transformers was investigated from the viewpoint of insulation, cooling performance and the less-flammability evaluation.
These results showed that the basic characteristics of 20cSt Silicone Liquid were verified in application to a less-flammable transformer.

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