Integration of Asset Management and Smart Grid with Intelligent Grid Management System

Transcription

1 IEEE Transactions on Dielectrics and Electrical Insulation Vol. 2, No. 6; Deceber Integration of Asset Manageent and Sart Grid with Intelligent Grid Manageent Syste M. Hanai 1, H. Kojia 1, N. Hayakawa 1, K. Shinoda 2 1 EcoTopia Science Institute, Nagoya University 2 Departent of Electrical Engineering and Coputer Science, Nagoya University Furocho, Chikusaku, Nagoya Japan and H. Okubo 3 3 Departent of Electrical and Electronics Engineering, Aichi Institute of Technology 1247, Yachigusa, Yakusacho, Toyota 47392, Japan ABSTRACT Electric power transission and distribution (T and D) systes are coposed of a great deal of aged apparatus, which ay cause a decrease in reliability owing to their deterioration. In order to aintain high efficiency and high quality in T and D systes, the authors have proposed an intelligent grid anageent syste (IGMS), which deterines the optiu aintenance strategy and optiu power flow control based on condition onitoring and diagnostic results of the operating power apparatus. This eans that the IGMS essentially includes both concepts of an asset anageent syste and a sart grid. Further, the IGMS optiizes power flow routes and aintenance plans based on the failure risk, T and D loss, overload operation, life estiation of the power apparatus, custoer outage, and other etrics. The ipact of individual apparatus failure affects the entire T and D syste s perforance, causing blackouts and secondary failures. Reduction in reliability of whole syste is highly dependent on ageing of the aterials. The IGMS evaluates all of the events occurring in the T & D syste as the cost. Additionally, the risks are evaluated in the cost according to the ipact of the failure rate estiated by the condition onitoring diagnosis results of the power apparatus. Insulation syste deterines the transition in reliability and aintenance cost of the syste. In this paper, the IGMS is applied to T and D syste odels including aged apparatus, such as transforers and circuit breakers, and suitable power flow routes and aintenance strategies are derived. Consequently, by the effective application of the IGMS, the syste reliability can achieve an optiu state, and the total cost can be iniized. Index Ters Energy anageent, diagnosis, risk analysis, aintenance, condition onitoring, sart grid, asset anageent, power flow control, power grids. 1 INTRODUCTION HIGH reliability and quality in electric power supply systes are required because of a rise in the standard of living. A sart grid is proposed as one of the solutions of this proble. A T and D syste is coposed of any apparatus that are usually aged individually, and suitable aintenance that ensures the reliability of a T and D syste is required. The reliability of a T and D syste usually increases with aintenance cost. On the other hand, the cost of an event such as an accident or an outage decreases as the syste reliability increases [1 4]. Furtherore, when electric power flows through lowefficiency apparatus and longdistance transission lines, the power delivery cost should increase. To optiize the balance between cost efficiency and quality Manuscript received on 31 January 213, in final for 24 July 213. iproveent in an electric power supply, it is necessary to diagnose the present condition and to estiate the future perforance of operating apparatus in the T and D syste based on a condition onitoring and diagnosis (CMD) syste. Most of significant paraeters in ters of the reliabilities and reduction in reliabilities of aterials are taken fro literatures fro the point of view of perforance and ageing of insulation aterials. Our purpose is to operate a T and D syste effectively by aintaining a balance between cost and quality fro a short tie frae to long periods of years. As a ethod that solves this proble, we propose an intelligent grid anageent syste (IGMS). We have been conducting research on the IGMS for several years [5 12]. In this paper, the concept, algorith, and effectiveness of IGMS are presented. The objective function of the IGMS includes both: 1) the costs of the T and D loss and the outage loss /13/$ IEEE

2 2196 M. Hanai et al.: Integration of Asset Manageent and Sart Grid with Intelligent Grid Manageent Syste according to the present perforance, 2) the costs of the failure loss and apparatus aintenance cost by future perforance of the entire T and D syste optiization. Thus, the optial control that includes the present power flow and the future aintenance of a T and D syste is achieved. Consequently, IGMS is the integration of power flow control and aintenance technology based on condition onitoring of power apparatus. 2 CONCEPT AND ALGORITHM OF IGMS 2.1 BASIC CONCEPT The total T and D cost reaches a iniu when a balance between cost and quality of electric power supply is found, and then, the T and D route is selected. Thus, the cost and reliability ust be evaluated for the entire T and D syste, and not for individual apparatus. The concept of the IGMS is shown in Figure 1. The present perforance and the history of apparatus operation and aintenance are acquired by diagnostic systes and inforation systes. All data are collected at the control center. The T and D syste is coprehensively evaluated there in ters of the T and D loss, T and D syste reliability, overload operation, total cost, and other paraeters. Based on the evaluation, the T and D syste is operated optially. Moreover, the Figure 1. Concept of intelligent grid anageent syste (IGMS). Figure 2. Description of IGMS. Figure 3. Algorith for optiization of cost and reliability in IGMS. aintenance ethod and schedule of the apparatus are evaluated, and the optiu aintenance strategy is proposed. An IGMS is the integration of an asset anageent syste and a sart grid, as shown in Figure 2. The horizontal axis shows a tie range, and the vertical axis shows the coplexity of the aintenance of the apparatus. The asset anageent syste works by using TMB (Tiebased aintenance) and CBM (Conditionbased aintenance) over the long ter. Although asset anageent takes into account only the degradation of the apparatus, power flow control is not carried out. On the other hand, power flow control does not take into account the degradation of the apparatus as asset anageent does. The IGMS can iniize the ipact of the individual reliability of an apparatus on the whole insulation syste by using power flow control and apparatus aintenance. An iportant point is that this evaluation converts all events into the cost, which is a concept that is essentially different fro that of other systes. 2.2 SIMULATION PROCEDURE The algorith of the IGMS is shown in Figure 3. The algorith consists of the following five basic steps: (Step 1) Apparatus reliability estiation: The current and future reliability and perforance of the apparatus are estiated based on the diagnosed results and the apparatus history data [8]. (Step 2) Syste and supply reliability estiation: Failure patterns of the T and D syste are calculated chronologically with a sequential Monte Carlo siulation by using T and D syste data and the estiated apparatus perforance. (Step 3) Evaluation of T and D cost: According to the failure patterns in Step 2, all probable events in the T and D syste are evaluated as cost. The su of all costs (T and D cost) is calculated, and the iniizing conditions are derived. (Step 4) : As aintenance iproves apparatus perforance and reliability, Steps 1 3 are repeated as conceivable aintenance is perfored.

3 IEEE Transactions on Dielectrics and Electrical Insulation Vol. 2, No. 6; Deceber (Step 5) Coprehensive evaluation: The iniu T and& D cost and corresponding conditions are extracted fro all the calculated values obtained in Steps 1 4. The extracted result suggests the optial aintenance strategy and the optial T and D power flow routes. 3 SIMULATED T & D SYSTEM MODEL 3.1 OBJECTIVE FUNCTION The objective function of T and D cost z consists of any cost coponents. By iniizing z with nonlinear prograing, the iniu T and D cost and the optial T and D route are estiated. The objective function is shown in equation (1). in z SS2 Line 1 : 8 k 13 MVA SS4 CB 6 Coalfired theral Load C 85 MW ij ( i, Line OverEquip n noutload k kpowerequip : Transforer : Circuit breaker Line 3 : 2 k, 6 MVA CB 1 Line 6 : Line 2 : 8 k 275kV 12k, 13 MVA 125MVA CB 3 a ( X ) c g ( X CB 2 n Line 5 : 5 k, 5 MVA Line 9 : 1 k, 5 MVA SS6 ij e ( X ) ( X k ) ) Line 4 : 1k 77kV Load E 2 MW ij ( i, OverLine n noutload MentEquip h ( X FailEquip b ( X ) SS5 Load D 2 MW Hydro Line 8 : 2 k, 5 MVA Figure 4. Billinton test syste [13]. f ij d ( X ) n ( X ) ) CB 4 SS1 Load A 2 MW Line 7 : 12 k, 125 MVA SS3 CB 5 Load B 4 MW (1) where, z: the objective function of T and D cost X ij : the transission power flow fro substation SS i to SS j X : the electric power flow in apparatus X n : the outage power of load n a ij : the cost of the T and D loss during noral operation b ij : the cost of the T and D loss during overload operation c : the daage caused by a shortened service life due to overload operation d n : the custoer s outage cost e n : the supplier s outage cost f : the aintenance cost g : the fuel cost of power apparatus h : the repair cost of failed apparatus Line: the sets of transission lines OverLine: the sets of overload lines OutLoad: the sets of outage loads MentEquip: the set of apparatus in the T and D syste FailedEquip: the set of failed apparatus in the T and D syste PowerEquip: the set of power generation apparatus The custoer s outage daage depends on the types of custoers [13]. cost and apparatus price of references are used [2, 14], and the repair cost of the failed apparatus is assued to be onethird of the apparatus cost. In a power transforer, the echanical strength of the insulation paper is degraded by the teperature rise of oil. Thus, the service life of a transforer (TR) is shortened by overload operation. This shortened service life of a TR fro overload operation is estiated according to reference [15]. 3.2 T & D SYSTEM MODEL AND TARGET APPARATUS In Figure 4, a Billinton test syste (RBTS) for an evaluated 275 kv / 77 kv T and D syste is shown, which contains three power stations and six substations with a total load of 185 MW [13]. The substations are in a doublebus arrangeent. RBTS can easily provide the coprehension required in the various steps in odeling, the set of assuptions involved, the algorithic developent, and the calculation process used to evaluate the reliability of the syste better than the IEEE reliability test syste [16]. The rated capacity and the length of transission lines are defined. The circuit breaker (CB) and TR ages in the odel are assued for two conditions, which are a new installed condition and an inhoogeneous aged condition. A new installed condition eans that each apparatus is new. An inhoogeneous aged condition eans that the anufacturing year of each apparatus is generated at rando in a certain country, and the resulting ages are Figure 5. Failure rate of each apparatus [17, 18].

4 2198 M. Hanai et al.: Integration of Asset Manageent and Sart Grid with Intelligent Grid Manageent Syste assigned to CBs and TRs. Literature data were used for the failure rate of the CB [17] and TR [18], as shown in Figure 5, instead of the diagnosed ones for siplification of calculations. The failure rate excepting the target apparatus was assued constant, as listed in Table 1 [17 19]. Table 1. Failure rate of other target apparatus [1719]. insulator was decreased by half, which is described by the general degradation characteristics. On the other hand, in this calculation, the life decrease of the apparatus is estiated as the cost fro an increase in breakdown probability and increase in the depreciation expense. The power failure daage of a consuer changes with iportance, such as the industry of the consuer. Thus, the average value of the power failure daage was used. 4 POWER FLOW CONTROL STRATEGY OF IGMS 4.1 POWER FLOW CALCULATION It is iportant to stabilize voltage while operating an electric power syste. Therefore, the total difference between the actual voltage and the rated voltage added to each line was used in the control function F control. The voltage phase difference between the power generation plant, change of a tap with a transforer, and onoff of each switch were controlled to iniize this control function. As a result, the best voltage in each node and electric energy flow in a syste were acquired. Control function F control is shown in equation 2. F control ( i, Line A i, V ( i, V n( i, n( i, ( (2) where, F control : the control function Line: the set of all lines A (i, : the iportance of the line between substation SS i and SS j V (i, : the voltage of the line between substation SS i and SS j V n(i, : the rated voltage of the line between substation SS i and SS j In this calculation, iportance A (i, yielded a value proportional to the aount of power failure daage in the directly connected load. The electric power generated in the power plant is sent to consuers through power lines and transforers. In that case, the losses fro electrical resistance in a power line, in a transforer winding, and by hysteresis of the core in a transforer occur. If three phases of voltage are balanced, electric power losses P Line fro the resistance of a power line are decided by resistance R and load current I of power lines. The transforer was considered as an apparatus with a decreasing life. In the considered transforer, it was assued that the teperature increased to 4 ºC when the load factor increased to 1%. When an additional teperature rise of 7 ºC occurred, the lifetie of the solid V POWER FLOW OPTIMIZATION OF NEW INSTALLED NETWORK The optial power flow control in the case when all electric power apparatus in Figure 4 are in a newly installed condition is considered. The failure rate of the apparatus in this case was assued constant, as listed in Table 1. In power flow control, the switches of both the ends of a power line are operated by various patterns. All connecting patterns are nubered, and the typical patterns are shown in Table iniizes the T and D loss because there is high reactive power flow in Line 3 with 65.4 MVA in, when all the lines are connected as shown in Figure 6. In this case, the entire cost is coparatively low and 32 turned out to be the optial power flow control. The power flow was calculated for each control pattern. Moreover, in the power flow of each control pattern, all the Control nuber Table 2. Copendiu of control patterns. Line Load A E All ON ON ON ON ON ON ON ON ON ON All ON 8 All ON OFF ON ON ON ON ON ON ON ON All ON 32 All ON ON ON OFF ON ON ON ON ON ON All ON 4 All ON OFF ON OFF ON ON ON ON ON ON All ON 64 All ON ON ON ON OFF ON ON ON ON ON All ON 96 All ON ON ON OFF OFF ON ON ON ON ON All ON 128 All ON ON ON ON ON OFF ON ON ON ON All ON 16 All ON ON ON OFF ON OFF ON ON ON ON All ON 192 All ON ON ON ON OFF OFF ON ON ON ON All ON 2 All ON OFF ON ON OFF OFF ON ON ON ON All ON 1152 All ON ON ON ON ON OFF ON ON OFF ON All ON 248 All ON ON ON ON ON ON ON ON ON OFF All ON ONOFF 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 11, 12, MW 14.2 MVar 5.6 MW 14.2 MVar 6.1 MW, 65.4 MVar CB2 2.7 MW, 6.5 MVar CB MW.2 MVar 19.8 MW 9.6 MVar CB MW.7 MVar 27.3 MW 19.6 MVar Figure 6. Power flow pattern MW.7 MVar

5 IEEE Transactions on Dielectrics and Electrical Insulation Vol. 2, No. 6; Deceber CB 1 CB 2 CB 3 Table 3. Apparatus diagnosis and failure rate. Tie (a) ~ hour (b) ~ 14 hour (c) 14 hour ~ Diagnosis result Failure rate [F/year] Diagnosis result Failure rate [F/year] Diagnosis result Failure rate [F/year] Noral state Noral state Noral state Noral state Noral state Abnoral state Noral state Abnoral state Abnoral state was no longer optial. Then, the control turned off CB 3 and separated Line 5. By changing to 16, the cost of the su total by failure without CB 3 decreased. As a result, although soe T and D losses increase as copared with the first state, because an accident involving the entire syste can be prevented, the total cost is aintained at the iniu with optial power flow. Furtherore, tie arches on, and at the 14th h, it is assued that abnoralities are found in the control current of CB 2. It is diagnosed that the failure rate of CB 2 rises to.5 F/year at this tie. In that case, the total cost is iniized by changing to 192, which turns Line 3 on and Line 4 off. Table 4. Power flow control pattern and total cost of the new installed network : ON : OFF (a) hour 36.2 (iniu) (b) 14 hour (iniu) 38.8 (c) 14 hour (iniu) Total cost [k / h, 1*US$/h] phenoena that ay occur in electric power systes, such as T and D loss and equipent failure, are converted into cost. The control that has the iniu cost aong all the control patterns is judged as optial. Condition onitoring of the apparatus, such as the partial discharge diagnosis and control current diagnosis, is perfored every hour for each circuit breaker (CB 1 to CB 3) in the syste of Figure 4, and power flow control is applied according to the diagnostic results. The diagnosis result and optiu power flow control at each tie are suarized and shown in Tables 3 and 4. Before a certain tie (here, we define this tie as h), it was diagnosed that the state of each CB was noral. Thus, the failure rate of each CB was sall, that is,.53 F/year, as shown in Table 3. In that case, the control ( 32 in Table 4) that can iniize the T & D loss becoes the optiu control. It is assued that the UHF sensor operating online detects a partial discharge in CB 3 at h and displays an alar for an abnoral state [2]. If a failure such as a grounding accident occurs in CB 3, it is necessary to turn off all CBs surrounding CB 3 for a certain tie. There is a possibility that the influence of an accident ay affect the entire syste. Because the failure risk of CB 3 becae large in this state, the total cost increased, and POWER FLOW OPTIMIZATION OF INHOMOGENEOUS AGED NETWORK The case of an inhoogeneous aged network, as shown in Figure 7, is considered. In this case, Line 1 has a highly aged deterioration state of 55 years, and the average years of deterioration of the apparatus are approxiately 2. In this case, 4, as shown in Table 2, turned out to be the optial power flow control. This pattern serves as a control that avoids the daage accopanying failure by turning Line 1 off that has apparatus with a high failure rate while turning Line 3 off. The effect of this control is shown in Table 5. However, the failure rate of the CB in the Line 1 connection is large, SS2 (2) (22) Line 3 : (21) (11) Line 1 : Line 6 : Line 2 : (55) (19) (19) Line 7 : (24) SS4 (15) (6) Line 5 : (16) SS6 Line 4 : (21) Line 9 : (9) (19) Line 8 : (21) SS5 (21) SS1 (12) SS3 Figure 7. Apparatus condition age of inhoogeneous aged network. Table 5. Power flow control pattern and total cost of inhoogeneous aged network. 4 2 : ON : OFF (a) hour 44.7 (iniu) 47.4 (b) 14 hour 5.1 (c) 14 hour (iniu) (iniu) Total cost [k / h, 1*US$/h]

6 22 M. Hanai et al.: Integration of Asset Manageent and Sart Grid with Intelligent Grid Manageent Syste and the failure daage cost is increased. For this reason, in the control using Line 1, the influence of failure and the total cost will increase. If the control ethod is changed to 4, although soe T and D losses increase, the failure daage cost can be reduced greatly, and the total cost can be iniized. With the sae case study of the power flow optiization with a new network, before a certain tie (here, we define this tie as h), it was diagnosed that the state of each CB was noral. In this case, 4 is optial. It is assued that the UHF sensor operating online detects a partial discharge in CB 3 at h and displays an alar as the abnoral state. Because the failure risk of CB 3 increases, the total cost rises and 4 is no longer the optial pattern. Then, the control separates Line 4 and Line 5 and turns Line 3 on. By changing to 2, the cost of the su total by failure without CB 3 is iniized. Furtherore, at the 14th hour, it is assued that abnoralities are found in CB 2. Additionally, in this case, the total cost is iniized by 2. By using the IGMS as entioned above, the power syste that has a deterioration apparatus can be controlled by a ethod that reduces not only the cost of T & D losses but also the daage cost due to apparatus failure. 5 MAINTENANCE STRATEGY OF IGMS 5.1 APPARATUS FAILURE RATE AND MAINTENANCE COSTEFFECTIVENESS To estiate the optiu aintenance strategy, the IGMS can analyze the T & D cost for all cobinations of three aintenance ethods (regular aintenance: RM, overhaul: OH, and replace: RP) for all apparatus. Figure 8 shows the aintenance effect. CBs are tested annually for ordinary conditions by RM. The arcing chaber of a CB is exchanged in the OH, and half of the CB is replaced. The RM cost, OH cost and RP cost are assued to be.8%, 2%, and 1% of the apparatus price, respectively. However, such calculation requires large aounts of coputing tie. For siplification of calculation in this paper, three CBs with high failure costs were selected for evaluating the optiu ethod and tiing for aintenance. Literature data were used for the failure rate of the CB [2], as shown in Figure 5, instead of the diagnosed ones for siplification of calculations. In this paper, the aintenance strategy plan was calculated for two cases. One case is that all apparatus are newly installed as in Section 4.2, and the other case is that the apparatus are aging with the distribution shown in Figure 7. The failure rate excepting the target apparatus was assued constant, as listed in Table 1. To obtain the optiu aintenance strategy, the evaluation period was designated. In this paper, the evaluation period was fixed at 6 years, which was considered to be sufficient for the average life span of the electrical apparatus. All of the possible aintenance plans for the evaluation period were extracted by an exhaustive search. Then, for each aintenance plan, the total T and D costs in the evaluation period were calculated. To calculate the total T & D costs of all the possible cobinations of three aintenance ethods, the tiing of the aintenance and deterining which apparatus to apply aintenance during the evaluation period are required. By coparison of the total T & D costs of each aintenance plan, the optiu aintenance plan that iniizes the total T and D cost was derived. However, such calculation requires an enorous aount of tie. Therefore, to siplify the calculation, the interval between calculations was fixed at three years. The optiu aintenance plans of selected CBs (CB4, CB5, and CB6) that were connected to different load capacities (Load A: 2 MVA, Load B: 4 MVA, Load C: 85 MVA) were derived, and optiu aintenance plans were evaluated. 5.2 OPTIMUM MAINTENANCE PLANS OF CBS IN NEW INSTALLED NETWORK In this case, all apparatus that include the target apparatus in the odel are newly installed, so the nuber of aged years is zero at first. The details of each plan and the transitions of the cuulative cost are shown in Figure 9 and Table 6. It is found that the optiu aintenance plans vary aong different load capacities. In the case of CB5 connected to a 4MW load, the tiing of the OH and RP are shifted to three years shorter than those of CB4. This is attributed to the outage size induced by the CB failure. Because CB failure results in the outage directly, the larger load requires a higher priority for the reliability. When CB6 is connected to the largest load of 85 MW, it requires exceedingly higher reliability; hence, early replaceent is required. Thus, the optiu aintenance plan of CB6 was deterined to apply RP twice at the 21st and 41st year, respectively. Despite carrying out RP twice during the evaluation period, the total T and D cost is reduced as copared with the TBM, which applied RP only once Intelligent Grid Manageent Syste IGMS (CB4) IGMS (CB5) IGMS (CB6) Tie Based TBM (CB4) TBM (CB5) TBM (CB6) RM.8 OH.4 Age of apparatus Figure 8. effect. RP Operation Year [year] Figure 9. Coparison of transitions of the cuulative cost with new CBs.

7 IEEE Transactions on Dielectrics and Electrical Insulation Vol. 2, No. 6; Deceber Table 6. Power flow control pattern and total cost with new CBs. Method IGMS TBM Start Age [Year] Target Equipent CB4 CB5 CB6 CB4 CB5 CB6 Load Capacity [MW] Tiing [year] OH , 42 12, 24 42, 54 12, 24 42, 54 12, 24 42, 54 RP Cost Reduction to TMB [%] Table 7. Power flow control pattern and total cost with inhoogeneous aged CBs. Method IGMS TBM Start Age [Year] Target Equipent CB4 CB5 CB6 CB4 CB5 CB6 Load Capacity [MW] Tiing [year] OH RP 9, , , 39, 12 3, 42 18, 48 6, 18 36, 48 24, 54 9, 27 39, 57 15, 45 Cost Reduction to TMB [%] OPTIMUM MAINTENANCE PLANS OF CBS IN INHOMOGENEOUS AGED NETWORK In this case, there was an average of 2 years of aging, as shown in Figure 7. The aintenance of CB4, CB5, and CB6 was also optiized. These results are shown in Figure 1 and Table 7. Because there are any old apparatus as copared with all the newly installed apparatus, as shown in Figure 8, the nuber of OHs is increased. On the other hand, CB6 has the longest aging in three CBs at the start tie of the IGMS. Though the aging of CB6 is 15 years, which is half of the design life, this aging does not affect the nuber of RP. Because the nuber of OHs and the breakdown probability increase the apparatus ages, in both TBM and IGMS, the costs of an aging syste are approxiately 2% higher than that of a newly installed syste. At the 6th year, the cost of the IGMS is lower than the cost of the TBM, whether the average age is zero or Intelligent Grid Manageent Syste IGMS (CB4) IGMS (CB5) IGMS (CB6) Operation Year [year] Tie Based TBM (CB4) TBM (CB5) TBM (CB6) Figure 1. Coparison of transitions of the cuulative cost with inhoogeneous aged CBs. years. This is the result of calculating so that the cost at the 6th year of operation of the IGMS shall becoe the iniu because the evaluation period was considered to be 6 years. For this reason, in the interediate stage by the 6th year, a situation where the cost of TBM becoes cheaper than that of IGMS also exists. This state occurred when replaceent was carried out. Because the aount of oney of replaceent each tie is large, even if IGMS is applied, it is thought that the cost of IGMS is higher than that of TBM teporarily. By coparison with TBM, the total T and D costs with IGMS are reduced by optiu plans in any case; hence, the effectiveness of IGMS is verified. Fro those results, it is ascertained that the IGMS can derive the optiu aintenance plan with consideration of the priority of reliability that is attributed to the outage scale induced by the CB fault. 6 CONCLUSION The essential proble for the operation and control of power T and D systes is to search for the optiu balance between cost efficiency and quality of a power supply. In order to find a solution to this proble, the authors have proposed the IGMS. In the IGMS, all events in the T and D syste were evaluated as T and D costs in any aspects, such as failure, T and D loss, life estiation of apparatus, outage, repair, and aintenance, and the optiu aintenance strategies and optiu power flow route were predicted by iniizing the entire T and D cost. The IGMS can iniize the ipact of the individual reliability of an apparatus on the whole insulation syste by using power flow control and apparatus aintenance. The IGMS contains the concept of both a sart grid and an asset anageent syste. In this paper, the IGMS was applied to derive a suitable realtie power flow control based on condition onitoring and the diagnosis results of apparatus. In addition, to consider the apparatus with any coponents such as a sart grid, an optiu aintenance strategy was derived. The IGMS was applied to derive the aintenance strategy of the CBs, and the effective results were indicated. The IGMS can actually deterine the appropriate frequency of aintenance and reduce the T and D total cost. The optiu aintenance strategy of the IGMS can reduce the T and D loss and the aintenance cost ore than TBM. As the result, the IGMS has the potential to be developed into a ore effective tool for future T and D systes.

8 222 M. Hanai et al.: Integration of Asset Manageent and Sart Grid with Intelligent Grid Manageent Syste ACKNOWLEDGMENT A part of this work was supported by JSPS KAKENHI ( ). REFERENCES [1] M. Schwan, K. Schilling and A.A. de Melo, Reliability centered asset anageent in distribution network process and application exaples, 19th Int l. Conf. Electr. Distribution, No. 682, 27. [2] G. Balzcr, K. Bakic, H.J. Haubrich, С. Neuann, and С. Schorn, Selection of an optial aintenance and relaceent strategy of H.V. apparatus by a risk assessent process, CIGRE, B313, 26. [3] D.G. Perez, G.L. Hurtado, M.A. del Rey Lopez de la Torre, New asset anageent practices for T and D utilities within deregulated power arkets, CIGRE, B315, 28. [4] C. Neuann, End of life estiation and optiization of aintenance of HV switchgear and GIS substation, CIGRE, A3 22, 212. [5] F. Endo, M. Kanaitsu, H. Kojia, N. Hayakawa, and H. 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Masahiro Hanai (M 6) was born on 7 March He received the Ph.D. degree in 28 in electrical engineering fro Nagoya University, Japan. In 1983, he joined Toshiba Corporation, Tokyo, Japan, where he developed gasinsulated transforers and researched highvoltage test techniques. Since 21, he has been a Professor with the EcoTopia Science Institute, Nagoya University. Dr. Hanai is a eber of IEE of Japan, a eber of CIGRE and a chair of IEEE DEIS Japan Chapter. Hiroki Kojia (M 11) was born on 7 Deceber He received the Ph.D. degree in 24 in energy engineering and science fro Nagoya University. Since 24, he has been at Nagoya University and presently he is an Associate Professor of Nagoya University at the EcoTopia Science Institute. Dr. Kojia is a eber of IEE of Japan. Naoki Hayakawa (M 9) was born on 9 Septeber He received the Ph.D. degree in 1991 in electrical engineering fro Nagoya University. Since 199, he has been at Nagoya University and presently he is a Professor of Nagoya University at the EcoTopia Science Institute. Fro 21 to 22, he was a guest scientist at the Forschungszentru Karlsruhe /Gerany. Prof. Hayakawa is a eber of IEE of Japan and a eber of CIGRE. Kosei Shinoda was was born on 11 April He received the B.S. degree in electrical engineering in 211 fro Nagoya University. Currently, he is a Master Course student of Nagoya University at the departent of Electrical Engineering and Coputer Science. Mr. Shinoda is a eber of IEE of Japan. Hitoshi Okubo (M 81) was born on 29 October He received the Ph.D. degree in 1984 in electrical engineering fro Nagoya University. He joined Toshiba Corporation, Japan in 1973 and was a anager of high voltage laboratory of Toshiba. Fro 1976 to 1978, he was at the RWTH Aachen, Gerany and the TU Munich, Gerany. Fro 1991 to 212, he was a Professor of Nagoya University at the Departent of Electrical Engineering and Coputer Science. And presently he is a Professor of Aichi Institute of Technology at the Departent of Electrical and Electronics Engineering. Prof. Okubo is a eber of IEE of Japan, a eber of VDE and a eber of CIGRE.