Tohoku Electric Power Research Articles

混合粒径砂３次元海浜変形モデルのベクトル並列計算

Simulating 3-D beach deformation numerical model with usual scalar computer, computation load is considerably heavy even for prediction of seabed evolution in the region of 4 kilometers around coastal structure in interval of 1 year. However, introducing vector-pararel computation suitable for each sub-model consisting of beach deformation model, computation performance can be efficiently increased. In this paper, a methodology of vector-pararel computation for 3-D beach deformation model subject to sediment sand of mixed grain size is investigated and proposed. This numerical model is applied to a field site of sea area around the Higashidori power plant of the Tohoku Electric Power Company and effect of vector-pararel computation is verified.

The development of effective heat and power use technology for residential in a PEFC co-generation system : Inaka, H. et al. Journal of Power Sources, 2002, 106, (1–2), 60–67

This paper describes recent activities on wind energy in Japan. The national “Sunshine Project” conducted by the Ministry of International Trade and Industry, was reviewed in 1990 to map out a new energy strategy in the Age of Global Environment. As a result, a new 500kW WECS R&D project has started in FY1991 and the operation started in FY1996. A number of basic and applied studies have been undertaken at the NEDO, the MEL and many universities. Interests in utilization of wind energy have spread gradually among power company. From FY1991, the Tohoku Electric Power Company has operated a 2,875kW Windpark(5 units of 275kW machine and 5 units of 300kW machine) at Tappi, where the annual wind speed is as strong as 10m/s.Researches and demonstrations are also conducted by some other power companies. MHI has developed middle-sized commercial WTGs. More than 800 units were exported to the United States and UK. IHI also developed 300kW machines. Fuji Heavy Industry is developing new concept machine of small to medium size.

An Integrated Support System for Protective Relay Setting Designed to Enhance Function Linkage and Improve Data Reusability

The task of setting a protective relay requires various analytical calculations and coordination studies, and is thus complex and labor-intensive. While proposed conventional support systems are equipped with the required calculation functions, the systems are problematic with regard to practicability. Our newly developed system not only integrates all required calculation functions based on a user-friendly GUI, but also dramatically improves system practicability mainly owing to the following developments: · Functions which enhance the linkage between comprehensive calculation functions and the database · Functions which automatically set parameters and execute standard-desirable fault calculations · A relay-type-independent simulation method of protective relay sequence logic and a user maintenance function of the protective relay sequence databaseThis system presently performs network linkage operations in 22 locations of the Tohoku Electric Power Company, and has achieved great success in many respects with regard to the protective relay planning and operation, such as thorough relay operation analysis at the time of a power system fault.

東北電力本店ビルの照明設備

東北電力本店ビルの照明設備

Long-Term Operating Experience of Mitsubishi Advanced G-Series Gas Turbine.

The next generation 1 500°C class G-series gas turbine has been developed by Mitsubishi Heavy Industries, Ltd. (MHI). MHI has been verifying its high performance and reliability of the latest technologies in the long-term field operation. We describe up-to-date operating status of both M501G (60 Hz unit, in a combined cycle verification plant of MHI Takasago, Japan) and M701G (50 Hz unit, in Higashi Niigata Thermal Power Station of Tohoku Electric Power Co., Inc., Japan)

Wind energy activities in Japan

This paper describes recent activities on wind energy in Japan. The national “Sunshine Project” conducted by the Ministry of International Trade and Industry, was reviewed in 1990 to map out a new energy strategy in the Age of Global Environment. As a result, a new 500kW WECS R&D project has started in FY1991 and the operation started in FY1996. A number of basic and applied studies have been undertaken at the NEDO, the MEL and many universities. Interests in utilization of wind energy have spread gradually among power company. From FY1991, the Tohoku Electric Power Company has operated a 2,875kW Windpark(5 units of 275kW machine and 5 units of 300kW machine) at Tappi, where the annual wind speed is as strong as 10m/s. Researches and demonstrations are also conducted by some other power companies. MHI has developed middle-sized commercial WTGs. More than 800 units were exported to the United States and UK. IHI also developed 300kW machines. Fuji Heavy Industry is developing new concept machine of small to medium size.

GPS Application for Synchronous Monitoring System at Multiple Location

Tohoku Electric Power Company and Tohoku University are cooperatively studying the effective use of a new monitoring .system using GPS (Global Positioning System). This system ensures achieving synchronous measurements at multiple remote electric supply station by using the time stamp facilities of GPS. First, this paper introduces briefly "Synchronous Monitoring System at multiple locations applying GPS techniques". Following section summarizes features of power flow fluctuation gotten by the developed monitoring system. The authors suggest some visual methodologies todisplay the features of the acquired data, and conduct a feasibility study on extracting hidden signals to identify insecure conditions in the power system.

Final Report of the Key Technology Development Program for a Next-Generation High-Temperature Gas Turbine

There is a strong demand for efficient and clean power-generating systems to meet recent energy-saving requirements and environmental regulations. A combined cycle power plant is one of the best solutions to the above [1]. Tohoku Electric Power Co., Inc., and Mitsubishi Heavy Industries, Ltd., have jointly developed three key technologies for a next-generation 1500°C class gas turbine. The three key technologies consist of: (1) high-temperature low-NOx combustion system. (2) row 1 turbine vane and blade with advanced cooling schemes, and (3) advanced heat-resistant materials; (2) and (3) were verified by HTDU (High Temperature Demonstration Unit). This paper describes the results of the above-mentioned six-year joint development.

The Advanced Cooling Technology for the 1500°C Class Gas Turbines: Steam-Cooled Vanes and Air-Cooled Blades

It is very essential to raise the thermal efficiency of combined cycle plants from the viewpoint of energy saving and environmental protection. Tohoku Electric Power Co., Inc., and Toshiba Corporation in Japan have jointly studied the next generation of combined cycle systems using 1500°C class gas turbine. A promising cooling technology for the vanes using steam was developed. The blades are cooled by air, adopting the impingement cooling, film cooling, and so on. The cooling effectiveness was confirmed both for the vanes and the blades using a hot wind tunnel. This paper describes the design features of the vanes and the blades, and the results of the verification tests using the hot wind tunnel.

On the Design and Construction of the Caisson for the Wave Power Generating System

The wave power generating system originally developed by Tohoku Electric Power Co. Inc. was installed in the concrete caisson composite breakwater at Haramachi Thermal Power Station port, which is under construction. The designed output of the system is 130KW, the largest in the world, and the performance tests have been conducted since September, 1996. The system hes water valve energy rectifiers and air chambers constructed in two caissons. In this paper, we discuss the technical characteristics of design and construction of the caisson for the wave power generating system.

Geothermal Energy: Clean and Reliable Energy for 21st Century. On the Geothermal Development by the Tohoku Electric Power Company, Inc.

Geothermal Energy: Clean and Reliable Energy for 21st Century. On the Geothermal Development by the Tohoku Electric Power Company, Inc.

Carbon dioxide fixation by microalgae photosynthesis using actual flue gas discharged from a boiler

To mitigate the effects of carbon dioxide discharged from a boiler in a power plant, CO2 fixation by microalgae photosynthesis was studied. For the algae cultivation, actual flue gas from a boiler was used in two sets of small-sized raceway-type cultivators installed at Tohoku Electric Power Company's Shin-Sendai power station. UsingNannochloropsis sp. NANNP-2 andPhaeodactylum sp. PHAEO-2 strains from the SERI collection, the microalgae were cultured semicontinuously and harvested periodically. From the results of the field test, the productivity of both strains using direct flue gas was almost on a par with that of bombed CO2 gas. Therefore, it was clarified that the direct blowing of flue gas into the cultivator did not adversely affect algal growth.

Development and implementation of a power system fault diagnosis expert system

This paper describes a fault diagnosis expert system installed at the Tohoku Electric Power Company. The main features of this system are careful selection of the inferencing input data, rapid inferencing, integration of the expert system with other systems in a practical structure, and the adoption of a domain shell. This system aims for improved practicability by using time-tagged data from circuit breakers, protective relays, and automatic reclosing relays in addition to the input data used in earlier systems. Furthermore, this system also uses data from fault detection systems that locate fault points within electric stations. This system uses an AI-specific back-end processor to perform inferencing rapidly. Additionally, this fault diagnosis expert system is interfaced and integrated with a restorative operations expert system, an intelligent alarm processing system, and a protective relay setting and management system. The authors developed and adopted a power system fault diagnosis domain shell to ease system development, and used the protective relay operation simulation function of a protective relay setting and management system for system verification. >

風力発電システムの運転特性シミュレーション-竜飛ウィンドパークにおける場合-

Tohoku Electric Power Company constructed a wind park composed of five 275kW windturbines (WT) at a cape TAPPI in AOMORI prefecture in 1991, and has begun an actual proof test from April 1992. A WT has a very unique point compared with other conventional electric power plants that the power of a WT is always fluctuating following the cube of wind speed and start-stop operation in very frequent. On the other hand, an induction generator is widely used for a WT, because it is very cost effective in manufacturing, maintenance and is very reliable. But the induction generator has a weak point producing high voltage fluctuation when connected into grid.Utility company has an obligation to keep voltage fluctuation within an allowable value, so we have to examine the performance of a WT previously. If there is any ploblem, we must take a suitable conter-measure. In order to evaluate the wind generator performance, simulation seems to be the best way. Hence, we made simulations on transient and normal characteristic of a WT, and found the simulation corresponded with the measured results very well.

Tappi wind-park of Tohoku electric power company

Tappi wind-park of Tohoku electric power company

Design experience of a base-isolation system applied to a computer center building

Design experience of the base-isolated new computer center of the Tohoku Electric Power Co. is described. This building after completion will be the largest isolated building in Japan with a total floor space of ≈10,000 m 2 . High-damping laminated rubber bearings are used as base-isolation devices.

An Advanced Integrated System for Electric Energy Supply Planning

Tohoku Electric Power Company has embarked on a company-wide long-range program for the introduction of a totally integrated computerized system for planning, operations and management with the objective of further sophisticated and enhanced business operations in the 21st Century. Research and development of the "Energy Supply Planning and Offical Intelligent Report System (ESPOIR)," which is the key to the realization of this broad vision, was started in 1983. The components of ESPOIR have been applied to the company's daily routine work as they were developed. As the result of this evolutionary development process, all fundamental subsystems were completed by 1988, and these subsystems have been integrated to realize a comprehensive electric energy supply planning system, namely, ESPOIR. The system has been successfully applied to power system planning and operations studies at the company. This paper describes the most advanced electric energy supply planning system of Tohoku Electric Power Company.

New Advanced Training Simulator Design for Power System Operations

In order to prevent human error, the importance of training and improving the skills of personnel involved in operations and maintenance can never be overly emphasized. First, this paper gives a brief overview of Tohoku Electric Power Company's new Training Center Scheme for 21st Century education strategies. Second, it explains the design concepts of an advanced training simulator for power system operators, which will be installed in the Center in 1990. Conventional simulators used at other electric utilities are capable of training personnel in frequency, load flow and voltage control. However, the most critical operations during periods of emergency and restoration of power supply are switchgear operations in which procedure operators must infer from protective relay information where the disturbance has occurred and how to restore trippcd-out transmission lines by separating disturbed lines or busbars. For this purpose, it is essential to have functions simulating the repercussions of fault phenomena activated by protective relays or breaker operations. This paper describes the most advanced technologies and innovations applied to the design of an epochal training simulator for power system operations.

On-Line Load Dispatching Control with Security Constraints at the Tohoku Electric Power Company

On-Line Load Dispatching Control with Security Constraints at the Tohoku Electric Power Company

On-Line Load Dispatching Control with Security Constraints at the Tohoku Electric Power Company

This paper presents an on-line load dispatching control system with security constraints which will start to operate in 1984 at the Tohoku Electric Power Company in Japan. One of these authors had developed a novel technique for an optimal power flow problem which was formulated based on the Decoupled Newton Load Flow method well recognized in bulk power systems. That is, the optimal power flow problem was formulated into P-0 active power and Q-V reactive power networks. Quadratic programming was employed to solve the OPF problem. The main algorithm of the developed system comprises the only P-0 active power network of the OPF problem. The system is able to minimize either generation costs or sum of squares of deviations between generator outputs and desired ones by controlling generators. The constraints consist of generator operating limitations and of power flow limitations which are restricted by thermal capacities or transient stability. If the problem has not a solution to satisfy the constraints, this system gives a solution which minimize sum of squares of the power flow violations. This on-line system is capable of dealing with a problem size of up to 180 buses, 200 lines, 26 controlling generators and 3 phase-shifting transformers.