Study on Model of Risks Assessment of Standard Operation in Rural Power Network

Transcription

1 Study on Model of Rsks Assessment of Standard Operaton n Rural Power Network Qngj L 1, Tao Yang 2 1 Qngj L, College of Informaton and Electrcal Engneerng, Shenyang Agrculture Unversty, Shenyang , Chna 2 Tao Yang, Correspondng author, College of Informaton and Electrcl Engneerng, Shenyang Agrculture Unversty, Shenyang , Chna { Qngj L, xmusyau@hotmal.com, Tao Yang, yangtaosx@yahoo.com.cn } Abstract. Operaton rsk s the prmary rsk to rural power company, and t s also an mportant part of securty rsk management. The paper establshes a model to assessed rsks of standard operaton n rural power network, based on Job Rsk Analyss (LEC). The example and applcaton of the model n rural power network securty rsk management system shows that t can realze the real-tme assessment of standard operaton rsk, the model use s smple and the assessment result s accurate. Ths study has mportant reference value to practcal applcaton of rural power securty rsk assessment. Key words: Model of rsks assessment, Standard operaton, Rural power network, LEC 1 Introducton Securty rsk assessment management s an mportant part of modern busness management and t also s an effectve means to ensure producton safety. In recent years, rural power companes are carryng out rsk assessment based on ts own contents and standards of rsks assessment. In these standards, some are cyclcal; others are real-tme. But they do not gve a clear and workable approach to acheve real-tme assessment that combne wth the standard operatng. Hazard dentfcaton and control measure s the core of real-tme assessment, and the model s the key to acheve real-tme evaluaton for standard operatng. Ths paper proposes an assessment model that s based on method Job Rsk Analyss (LEC) and has been mproved and perfected, so that t can be a good combnaton wth the rsk level of securty rsk assessment. The model can quantfy the hazard level and the effect of preventon measures, and then calculate the rsk level of ths operaton. Based on these remnders and descrptons of varous rsk factors leadng to the lkelhood and severty of accdents, operators can effectvely prevent accdents.

2 2 Background and platform 2.1 Background Securty rsk assessment management has been wdely used n fnance, nsurance and other ndustres. In November 2008, based on drawng and absorbng the nternatonal advanced management concepts and methods of securty, State Grd Corporaton arranged and compled The Securty Rsk Assessment Norm to Power Supply Enterprses and Supply Enterprse Securty Rsk Identfcaton and Preventon Operatons Manual. From the standpont of the company producton safety condtons, qualty of personnel, scene management, general management, the systematc assessment of enterprse securty management, the norm that manly prevents personal njury and man-made accdents evaluates enterprse securty rsk ratng and gudes enterprse to carry out securty management. The rsk calculaton formula of securty rsk assessment: Scorng rate = Σ the actual score of tems havng been checked / Σ total score of all the tems Table 1. Rsk ratng of securty rsk assessment scorng rate x x >x >x >x 0.4 x<0.4 rsk ratng Securty controlled Low rsk Medum rsk Hgh rsk Out of control 2.2 Platform In order to carry out securty rsk assessment management quckly, ChangChun Suburb Branch Company develop the "securty rsk assessment management system". The system development objectve s to acheve securty rsk assessment scentfc, convenent n the applcaton, relable, cost-savng effect, and provde comprehensve statstcal data to decson-makng to polcy-makers. The system s desgned and realzed by ASP.NET2.0 technques as well as the SQL 2000 back-stage database based on the hgher prevalence WINDOWS platform. System assessment s dvded nto two parts: real-tme assessment and perodc assessment. Perodc assessment s entrely based on The Securty Rsk Assessment Norm to Power Supply Enterprses ; real-tme assessment combnng wth standardzed operaton s a good complement to perodc assessment. Real-tme assessment model based on LEC method been mproved and perfected can quantfy the hazard level and mpact of control measures, and then calculate the rsk level of ths operaton and effectvely prevent accdents.

3 3. LEC Method 3.1 Introducton of LEC Method LEC method s also named Job Rsk Analyss. It s mathematc model as follow: D= L*E*C. (1) Value of D depends on the rsk possblty (L), the frequency (E) and the possble consequences (C). Ths assessment method s straghtforward and rsk level s clear. But the scores of LEC s determned based prmarly on experence, so the stuff who jon the assessment work must have experence and can make a far and objectve evaluaton of rsk control measures. 3.2 LEC scores and descrpton Table 2 shows the possblty of an accdent (L) and descrpton. Table 2. The possblty of an accdent (L) and descrpton score descrpton 10 Entrely possble 6 Very Lkely 3 Possble, but not often 1 completely unexpected 0.5 envsaged 0.2 Hghly unlkely 0.1 Impossble Table 3 shows frequency of exposure to hazardous (E) and descrpton. Table 3. Frequency of exposure to hazardous (E) and descrpton score descrpton 10 Contnuous 6 per day 3 Once a week, or occasonally 2 Monthly 1 Several tmes a year 0.5 Very rare Table 4 shows that accdent may result n the loss of the consequences (C) and descrpton. Table 4. Score C and descrpton

4 score descrpton 100 Dsaster, many deaths 40 Dsaster, several fataltes 15 serous, one death 7 Serous njury 3 Major accdents, dsablty 1 Small accdent, mnor njures 4. Real-tme assessment models 4.1 Assessments Model Frst, calculates the rsk value D for each hazard, and then sum total of ths assgnment as the rsk value, and prompts to the operator. There are many hazards preventon and control measures for each hazard. The score of preventon and control measures wll be multpled by the effect of e j, dvded by the total rsk value of rsk sources. Wth reference to table 1, the system reaches the safety rsk assessment rsk ratng. The mathematcal model can be descrbed by Equaton 2: n = 1 k ( e j D ( a b ) m j % + D b ) / D (2) j = 1 n = 1 Table 5 shows the value of a and b. Table 5. Relaton of a,b and D D Level of rsk a b >320 Extremely rsk ~320 Hgh rsk ~160 Sgnfcant rsk ~70 General rsk <20 Slghtly rsk The effects of a and b s that for a specfc hazard, based on level of rsk, rsk ratng of securty rsk assessment can be lmted n scope. For example, the value of D s >320, so the level of rsk s extremely rsk. For ths hazard, even f the operator take protectve measures s perfect, n the best case the rsk level of ths job s the hgh rsk. On the other hand, the level of rsk s slghtly rsk, even f the operator take no protectve measures, n the worst case the rsk level of ths job s the low rsk. Meanwhle, the models combne the level of rsk and rsk ratng of securty rsk assessment well.

5 Where m j % means the percentage level of protectve measure s control effect to a specfc hazard, and for hazard wth k- preventon measures, equaton s gven by Equaton 3: k j = 1 m j % = 1. Where k s the count of preventon measures. After that, the operator can easly score on the preventon measures to avod the uncertanty scores. Where e j means the effect of protectve effect to a specfc hazard, and e j [0,1].When a hazard wth the approprate control measures can be prevented, then the value of e j s great; else the value of e j s small. (3) 4.2 Expermental data For example,cuttng trees, the system calculate level of securty rsk based on mathematcal model. Table 6. Parameter values of cuttng trees Hazard D a b e Traffc accdent fallng Electrc shock Hurt by fallen trees The descrpton of hazards preventon measures for each hazard s no detal. Accordng by parameter values of table 6,the system Calculates scorng rate of securty rsk assessment :( ) / ( ) =0.87,Wth reference to table 1, concluson s Low rsk. Result value of 0.87 close to the 0.9 s realstc. 5. Concluson Real-tme rsk assessment plays an mportant role n the producton. The models combne LEC method and rsk ratng of securty rsk assessment well. By adjustng the value of each parameter, ther correspondng relatonshp s flexble. Wth the models, operator can vew the level of hazard rsk, and know the effect of preventon measures that wll be taken, then gan rsk level of ths job. For prmary operator, all nformaton can be warned before work, so accdents can be prevented obvously. At the same tme, large amounts of date from routne work can also serve as the bass for statstcal analyss and offer reference and decson servce to polcy makers. The value of coeffcent largely depends on experence wth professonal staff accordng to dfferent operatons, dfferent crcumstances to determne, and the fnal

6 value needs further study, standardzaton to make assessment more objectve and reasonable. Reference 1. State Grd Corporaton: The Securty Rsk Assessment Norm to Power Supply Enterprses. Chna Electrc Power Press, Bejng (2008) 2. State Grd Corporaton: Supply Enterprse Securty Rsk Identfcaton and Preventon Operatons Manual. Chna Electrc Power Press, Bejng (2008) 3. Ge Fengshan, and MaWanquan: New Power System Securty Rsk Management System and Evaluaton Methods. Chna Electrc Power Press, Bejng (2008) 4. LI Wen-yuan: Rsk assessment of power systems: models and applcatons. IEEE Press and Wley & Sons Inc, U.S. (2005)