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20 IEEE Transactions on Energy Conversion, Vol. 7, No.1, March 1992

I. Shiroumaru Yanai Power Plant Construction Office The Chugoku Electric Power Co., Inc.

INTEGRATED OPERATION AND MANAGEMENT SYSTEM

FOR

A 700MW COMBINED C-U'CLE POWER PLANT

1575-5 Yanai-Miyamoto-Shiohama Yanai-shi, Yamaguchi-ken, Japan

T. Iwamiya Omika Works Hitachi, Ltd.

5-2-1 Omika-cho Hitachi-shi, Ibaraki-ken, Japan

M. Fukai Hitachi Works Hitachi, Ltd.

3-1-1 Saiwai-cho, Hitachi-shi, Ibaraki-ken, Japan

Abstract - Yanai Power Plant of the Chugoku Electric Power CO., Inc. (Yamaguchi Pref., Japan) is in the process of constructing a 1400MW state-of-the-art combined cycle power plant. The first phase, a 350MW power plant, started operation on a commercial basis in November, 1990. This power plant has achieved high

site. Figure 1 shows an overall view of the entire power plant, while the inset shows the interior of part of power station No. 1 (3 units).

Power station No. 1 has six single-shaft combined cycle units, each comprising a gas turbine unit with a heat recovery steam generator (HRSG), a steam turbine and generator on the same shaft.

efficiency and high operability, major features of a combined cycle power plant. The integrated operation and management system of the power plant takes care of operation, maintenance, control of general business, etc., and was buil' using the latest computer and digital control and communication technologies. It is expected that this system will enhance efficient operation and management for the power plant.

INTRODUCTION

In a move beyond conventional control systems for thermal power plants, the system described in this paper incorporates artificial intelligence to assist efficient operation.

Yanai Power Plant, an LNG-fuelled combined cycle power plant, has an integrated operation and management system which controls all business operations, including equipment operation, maintenance, and management of general business of the plant. It combines the operation, management and automation technology accumulated by the Chugoku Electric Power Co., Ltd., over nearly 20 years with the latest hmiware and software technology of Hitachi. Ltd.

This paper describes mainly the integrated operation and management system of the combined power generating equipment, with emphasis on new technologies incorporated.

Yanai combined cycle power plant [ 11 is planned for a total generating capacity of 1400MW upon completion (Power Station No. 1: 700MW; Power Station No. 2: 700MW). It has self- contained LNG facilities for receiving, storage and supply on the

91 SM 335-0 EC A paper recommended and approved by the IEEE Energy Development and Power Generation Committee of the IEEE Power Engineering Society for presentation at the IEEE/PES 1991 Summer Meeting, San Diego, California, July 28 - August 1, 1991. Manuscript submitted January 31, 1991; made available for printing July 8, 1991.

Figure 1 Yanai Power Plant-Aerial View

0885-8969/9 2$03.000 1992

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The output of each unit is 117MW at 20°C ambient temperature, 700MW total for the entire power station. Table 1 shows the major specifications of this plant. Three units (350MW) of Power Station No. 1 started operation on a commercial basis in November, 1990 and the remaining three units (also 350MW) are expected to start operation on a commercial basis in December, 1992. Construction of power station No. 2, of 700MW, is now being planned. This will have an advanced type of gas turbine (combustion temp.; 1260OC). The fmt three units (350MW) tire expected to start operation on a commercial basis in March 1994.

Table 1 Major Equipment Specifications

Gas turbine

7001EA type Speed 3600 m i d

Open cycle single shaft Approx. 76MW at 2OoC

Heat recovery Two drum natural circulation type HFYLP: 6178 KPd843.4 KPa

I Non-reheat dual pressure type Steam turbine Approx. 41MW I Speed: 3600 min.'

139,000kVA

Voltage: 13.8 kV, Freq: 60 Hz Steam turbine Power factor: 0.9

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O P E W O N AND - To supply highquality electricity, the purpose of the power

company, it is necessary to improve operation and reliability of the equipment. It is necessary to plan all aspects of operation and management of the plant when it is put into operation.

In the planning stages of this new Yanai plant, integration and centralization of operations and management of various equipment, such as power generating equipment, LNG equipment and utilities, were of top priority, based on the scheme shown in Figure 2. For this purpose, the power station plant information system has been unified by setting up an automatic on-line system connected to the central dispatching center and fuel procurement department and by designing all support systems for labor saving operation and easy maintenance and management. It is also necessary to centralize the personnel who work in the power plant, so the central control room (for operating the system) and the engineering office (for mainte- nance and management) are next to each other.

When the business system and information are changed over from a paper-based system (documents) to a computer, a thorough training program is required. This was incorporatedinto the planning of the integrated operation and management system of the Yanai Power Plant.

Fully- Automated Stable Power-Supply

Fault diagnostic

System for Power

Maintenance Support

danagement support fi iT*r:yz - - 1 Education and Training

Creative activity for Upbringing of Human

Optimum Environment resources

for work

Figure 2 Consideratings for Construction of Integrated Operation and Management System

(1) System

a management computer for plant opemtion data processing, a control computer for automation, control equipment, a support- system computer for correcting operation faults and for routine test work, and a closed-circuit TV monitoring system for patrolling the site. The maintenance and management support system consists of a maintenance system computer for scheduling equipment maintenance, a workstation network, and a personal computer network for general business and management. The training support system consists of a personal computer system for displaying operational information and the operating procedures, and for simulating major equipment, a video system for learning and showing the procedure for dismantling and reassembling equipment, and a workstation for inputting data into the operation and A t e - nance support system and for displaying the operation and mainte- nance knowledge database.

As shown in Figure 3, the operation support system consists of

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/ Common Data Bank - Central Dispatching Total Network System Center (Chugoku EPC) LNG Control Center .

/ -

V

Training Room

Materials

42 VTR Monitor

Maintenance

Support System Work Station

Central Control Room

I I I

ween Monitor

Power Common Power station & LNG station No. 1 No. 2

off Ice

Figure 3 System Configuration

(2) Man-machine interface The man-machine interface is a key part of an integrated

operation and management system. The features of this interface for operators are described below. a. Operator’s console

This was designed so that two operators can monitor all important facilities of power stations No. 1 and No. 2, the LNG facilities, and utilities such as pure water equipment, drainage system, sea water equipment and so on from a centralized location. Since the range that can be monitored by one operator is 2 m or less, the panel width is 3.5 m. The plant data is highly centralized and monitored effectively using six CRT units, two

110 inch (2800 mm) rear’projection screens and four CCTV monitor units. The large screens have a wide angle of visibility so that the same data can be seen by several persons simultaneously and human errors such as oversight and misunderstanding can be avoided. As a result, it was possible to reduce the number of operators. In addition, the large screen can be used for other purposes, such as prearranging mal runs, etc., via a personal computer and a camera to indicate documents and drawings. Figure 4 shows a general view of the central contml room, including the operator’s console and the large screen.

Figure 4 Central Control Room

b. Unit control panel Impomt equipment, such as the oil pump for the turbine and electrical units, is operated and monitored using operation switches, manual-auto selector station, meters and so on; for most units, CRT-based operation and CRT display are used to minimize the width of the unit control panel. Figure 5 shows the unit control panels. Using only these unit control panels, periodic inspection and mal runs can be performed. The combined cycle power plant is made up of a number of units, each of which requires regular inspection. Interface points between operating units and the unit undergoing periodic inspection can be separated easily. Also, the unit control panel is located so that its operation does not interfere with that of the operator's console.

c. Central control room The central control room is like a business office with large windows on two sides, a high ceiling for an open atmosphere, attractively designed control panel and desks, warm colors, and unobtrusive illumination and air conditioning.

Figure 5 Unit Control Panel

The major tasks of operators in this power plant include starting-up, stopping and controlling the output of the plant. These operations are performed in accordance with commands from the central dispatching center, procedures established to correct failures or faults, procedures for routine operation, etc.. The operation

support system supports the operations described above. Figure 6 shows the configuraaon of the digital control system including this operation support system.

(1) Automatic system

permits fully automatic starting-up, stopping and controlling output The integrated digital control system of the power plant [2]

P l a n t 1."81 CRT baled operation

-

U"1t

l W S

-

.L .L LOCa

I.". I &can - - - - - - Asas - - - - - - -

Figure 6 Control System Configuration with Support System

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of the plant, making it as easy to operate as recent types of conventional thermal plant.

Planning for Plannin for Long Demands % Weeklykmands 3

(2) Optimum load operation

Estimation of the Followin Plannin for

Weeklysemands 3 D~~ D ~ ~ ~ &

The central dispatching center controls the output of all power

Actual Fuel Con-

Fuel sumption

Forecast

Operation of Yanai Power

plants of the company for required output and optimum consumption of LNG fuel. The integrated digital control system of the Y a n ~ Power Plant is connected to the center so that the center can start and stop units as required. Figure 7 is a flow diagram showing operation ‘ of the plant to meet load demand.

Operation Capability

Demand Balance ( ge%?znd) [ Day )

Station of the Day

Fuel con-

fl Operation Limitation

Facilities

Figure7 Flow Diagram of Operation for Load Demands

a. Supply and demand plan (long-term supply and demand plan, weekly supply and demand plan) . The load range in which the plant should be operated is determined by the central dispatching center on the basis of the rate of fuel consumption at that output and quantity of LNG on hand. This is the supply and demand plan. (It is necessary to consume sufficient LNG that there is storage capacity available by the time of the next LNG delivery. The power plant is the only consumer of LNG from the tanks, so the supply and demand plan is very important.)

b. Previous-day scheduling The optimum output pattern and operating schedule for the units is set by the dispatching center a day in advance to suit the supply and demand plan, then the information is sent to the plant.

c. Following-day operation In principle, units are started-up or stopped in accordance with the operation schedule for each unit set the previous day. Actual minute-to-minute output is determined by the automatic load regulator (ALR) at the plant in accordance with the supply data from the central dispatching center, and the number of units operating is determined by the anticipated output-change requirements.

(3) Fault diagnosis expert system A fault resulting in a unit being put out of operation requires

full knowledge by the operators of the way to correct the problem, and this is likely to depend on the individual dealing with the fault.

to the same knowledge. This system has the following main aims: Assuring effective functioning of operators who have limited experience. Ensuring that the effectiveness of action does not depend on the person. Selecting the best course of action when multiple alarms occur at the same time. Enabling operation by a small number of operators. Ensuring the accumulation and dismbution of operational know- how.

The system operates at the practical level, equivalent in range and depth to the operation manual. Figure 8 shows an example of support information.

Figure 8 Example: CRT Display of Fault Diagnostic - Expert System for Abnormality “Extremely Low Stand Pipe Level”

(Translated in English for convenience)

To overcome this problem, the control system incoprates an expert system (artificial intelligence) to enable all operators to have access

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. . . . . . . . . . . . . . . . . . . . . . . . . . . . . ......................... -. ............... _,_ . . . . . . . . . . . . . . . . ......................... -. ................... I I I . , I I , I , . . . . . . . . . . . . . . . ......................... -. ................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -....... ................. ~. ......... _,_. ...... , , . . , I I I I I , , , , , .............................. _,_. .. -. .......

. . . . . . . . . . . . . . .

, , , . , , , , , , , , , , ,

Correcting operating faults When an operating fault occurs, the role of operators is to ascertain current plant conditions. Most equipment or system faults rn covered by the automatic control system, so the first step is that the system checks the plant conditions through the on-line system and judges if the problem is being corrected. If not, the system gives guidance for manual intervention by operator(s).

(0XW)SrM PIPE L M L W ' G MER ( 0 3 a O ) L M L OF 3RUMNMY MEP T M FLU4 O f SWPLEHEWMY WiER LEVEL OF PVRE WATER TPNK

GRAPH

Inference and correction of faults The system operates by use of an inference program to identify the cause of a fault, and then gives guidance for operation to correct the problem. Sometimes it may be difficult to infer the cause, in which case multiple causes are suggested and the operator eliminates them in succession.

..I_. .. .,. .............. .-. ......... .,. ....... ~ ~ ~ : : : ~ : : : ~ : : : : SYSTEM

Sequence of fault and propagation of fault displays The sequence of fault display indicates the sequence of fault

MTERSYSID.~

alarms, and the fault propagation display shows the conse- quences that will result if corrective action is not taken.

Related data display To supplement inferences for troubleshooting from the knowledge database, additional plant information relating to the fault is given to the operators by CRT displays of the system diagram and operating history.

Knowledge database tool Knowledge is data that has been acquired by veteran operators. For a system like this, the most difficult problem is the way the knowledge should be expressed and the extent (depth and volume) it should be expressed, so the format shown in Figure 9 is used. The knowledge database is inputted into the computer easily using the knowledge data input tool interactively via a CRT on the basis of logic using ordinary words, and no knowledge of computer terminology is required.

INPUT AREA FOR EXPECTEO FACTORS I N P U T AREA FOR ANNUNCIATIONS

D I R E C T

FACTORS

INFW- TIffl F K N

C M R

I N m S T A T E

O W R

OPERATED

PNWNCI-

ATIONS

I I

t

. _,_ ... _,_ .. _,_ ... _,_ ...... . . . . . . . . . . . . . . . . . . ....................... -. .

I I INOPEFATI , , , , , , ........... -. .. - i. ............... -. . : ; : : ~ ...................... .,. . ' . .'. . ' . .'. . ' . '_ .

. . . . . . . . . . . . . ......................... -. ......... _,_ . . . . . . . . . . . . . . . I I I I I I I I ................... I . I I (2)MAHGE OVER PlMP I F DISaWlGE PRESSURE ......................... -

......................... -. .................. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I N P U T AREA FOR RELATED DATA

LOGIC MESSAGE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ......................... ~ .........._._.__.._ I I , . . I , , I I I , , , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ........................ .-. ......... __. ...... . . . . . . . . . . . . . . . ......................... ................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

................... ........ .......

- -.- -.--...... ........... ......... . . . . . . .

(4) Routine test work expert system Preventing mistakes in operation.

accordance with a manually-prepared weekly schedule. This routine test work is now done automatically. Such work increases in proportion to the number of units (about 20 tests per unit) in the combined plant resulting in an increased burden on operators. To perform such routine work automatically, a test system with the following aims has been set up:

Conventionally, an operator did routine test work in Performing maintenance on an optimum schedule. Operation using a small number of operators.

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Figure 10 shows an example of support information.

Figure 10 Example: CRT Display of the Routine Test Work Expert System

1) Determining and posting advance notice of routine test time By consideration of the hours of operation of the equipment and the operating history of the plant, the routine work to be performed is decided and the schedule of the day is displayed on the CRT at 9:OO AM every day.

2) Performing routine tests In AUTO mode, routine test work is carried out sequentially using instructions given by synthesized voice.

3) Judgment and recording of routine-test results Whether routine tests are acceptable is judged by monitoring using both time and plant data. If the results are unacceptable, suspected causes are displayed on the CRT. The results data are stored in the management computer and are also sent to the maintenance system as maintenance data. These acquired knowledge data are entered in the format shown in Figure 11. The most important aspect is to define what is used

. .

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ......................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .......I ...................................... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ............................................... . . . . . . . . . . . . . . . .........................

......... ...................... _,_ . . . . . . . . . . . . . . . . . . . . . . ................................... . . . . . . . . . . . . . . . . . . . . . . .............. .......-.... ...... START-UP TEST OF ST EMERGENCY

, , , , , , , . . , , , , , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . , , , , , , , , , , . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

................... ._ ........................ ___. .. .- ... _,_. ........ .- ... ..__._... ...... ................... ............ .............................................. ......................... ..... ...-................ ..............................................

ELECTRICAL FWLT

W I W T I C R S I T I C N

PROCEOURE OF JUDGEMENT I N P U T DATA

VALUE

........ ...... .,_. ........

I ................ . . . . . . . . . , , / . . . . . . . I , I

, , , , . . . . . . . I , I I ....................... .... .,_ ......... . . . . . . . , , , I

....-

PROCESS SI 0rEC.OIL CONTROL START ....... .,_ .............. .............. . . . . . . .

, , - ....................... Y ...... . . . . . . . - E . , No . . . . . . . ......... ...._ ....-. . . . . . . . . . . . . . . ....................... ~- SIARTIH; TIM OF TEST 0

INFW- 1- I H I

I - D

Figure 11 Example of Knowledge Database Format for Routine Test Work Expert System (Translation in English)

as the criterion of judging test results and how the deterioration due to age is managed. The knowledge database is inputted into the computer using the same knowledge data input tool as for the fault diagnostic expert system.

points regarding equipment are monitored by a combination of zooming lenses, panning cameras, and illumination to facilitate early discovery of serious faults or accidents that may lead to leakage or a fire. This system was selected because the ability of operators to patrol the entire LNG depot (a large space) is limited, and undesirable from the point of view of safety. There are two patrol methods; one is to operate the cameras manually, the other is an automatic method that switches from camera to camera

( 5 ) Patrol support system Part of patrolling the site, previously done by operators, is by

means of about 40 closed-circuit TV (CCTV) units; that is, the key

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automatically in accordance with a preset pattern. Figure 12 shows the display of CRT based operation for the patrol support system.

operating hours, and maintenance history. Parts are replaced at convenient intervals in order to prevent breakdowns.

Figure 12 CRT Based Operation for Patrol Support System by CCTV (Translated in English for convenience)

The usual concept of periodic maintenance has been changed to one of preventive maintenance, based on the present condition and use of the equipment. In this way, maintenance costs can be reduced by avoiding excessive maintenance, while reliability is maintained by maintenance adequate to prevent abnormal wear or failure. (1) Maintenance scheduling expert system

improvement for the following year is set up by evaluation of the condition of equipment from such factors as operating time and estimated remaining service life, performance, tendency to deteriorate, equipment history, outstanding problems, etc. There are two methods: one is based on scheduling and experience in the past, and the other is a query system using an AI inference program. The work procedures, such as dismantling and reassembly, expected service life of each part. drawings, instruction manuals, etc., which are required for scheduling, are entered into the optical filing system so that required data can be outputted when required through the on- line system connected with the maintenance system computer.

(2) Servicing support system

present condition of equipment and reviews the schedule in the maintenance scheduling expert system, and then estimates work cost, orders required parts, etc.. After the work is completed, data are registered in the equipment history file.

In this system, the planning of periodic inspection, repair, and

The system supports servicing activities by considering the

On-line equipment diagnostic systems are the key to preventive maintenance work.

The major elements are shown below.

a. Gas turbine service life monitoring system Gas turbines have many parts which must be replaced periodi- cally due to exposure to high temperam, such as combustor liners, transition pieces, and turbine blades or nozzles, etc. The service life of these parts is based on the number of start-ups,

b. Other systems perform a similar function or otherwise monitor the following major equipment;

Steam turbines HRSGs Denitration systems Condensers Gas turbine air compressors Control system air compressor

General business and management tasks, such as preparing daily reports and analysis reports, arranging meeting rooms, performing technical calculations, etc., functions not directly related to plant operations, are performed using a network of personal computers.

The amount of knowledge (information) available to the operators will determine the performance of the system. In the educational role, information stored in each subsystem can easily be viewed using a CRT interaction system, and the knowledge database can be modified without professional computer knowledge. Also, various educational materials stored convention- ally in the form of documents are stored graphically in the computer to make it easy to understand or for conducting training classes using video.

CONCLUSIONS

Yanai Power Plant uses the latest technology for LNG fuelled combined cycle power plants; operation and management systems have been improved over previous versions by integration, and high efficiency and high operability have been achieved. In addition, operations performed independently in conventional power plants, such as monitoring operations, maintenance work, general business, management work, etc., have been combined and systematized using the latest computer and digital control/communication technology. Operations, such as calculation, record keeping, storing of large volumes of data, and high-speed transmission of information are under computer control, leaving the staff free for tasks requiring thought and originality. Aiding the operators is an artificial intelligence inference system and extensive database. The system combines the experience and knowledge of the user with the hardware and software technology of the equipment manufacturers.

REFERENCES

[ 11 S. Shirakura et al., “Construction of a 700MW combined cycle plant for YANAI Power Station No. 1” ASME Paper No. 90- GT-37 1

[2] M. Iioka et al., “Hierarchical function-structured and Autono- mous control systems for fossil power plant”, IEEE Transac- tion on Energy Conversion, Vol. 3, No. 3 September 1988. PP. 548-553

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was born in Hiroshima, Japan in 1944.

He joined the Chugoku Electric Power Co., Inc. in 1962 and has been engaged in the planning and designing of automation systems for thermal power plants. He is the manager of the Electrical Engineering Section at the Yanai Power Plant Construction Office and of the Control Technology Section at Yanai Power Station. He is a Registered Professional Engineer (Electrical Engineering), and a member of the Society of Instrument and Control Engineers (Japan), Institute of Electrical Engineen of Japan, and the Thermal and Nuclear Power Engineering Society (Japan).

1 Iwam iva was born in Akita, Japan in 1945. He received a B.S. in elecmcal engineering from Akita University in 1968. He joined Hitachi, Ltd. in 1968 and has been engaged in the engineering of control systems for thermal power plants at the company’s Omika Works. He is a senior engineer in the Thermal and Hydroelectric Power Control and Instrumentation System Engineering Dept. of the Omika Works. He is a member of the Institute of Electrical Engineers of Japan, the Thermal and Nuclear

Gas Turbine Society of Japan. was born in Toyama,

Japan in 1954. He received a B.S. degree in mechanical engineering from Tokyo University in 1977. He joined Hitachi, Ltd., in 1977 and has been engaged in the planning and designing of instrumentation and control systems for thermal power plants at the company’s Hitachi Works. He is a senior engineer in the Thermal Power Plant Information and Control System Engineering Dept. at the Hitachi Works. He is a member of the Japan Society of Mechanical Engineers.

uki Fukai

T

Power Engineering Society (Japan), and the