(1996) Reliability Evaluation of Power Systems一书中介绍的可靠性评估PJM方法有下面几句话:2 X2 _: L! b5 Y, L
1)2 u' s8 w# h* |2 C: Z& W1 p1 I9 O3 ? It is necessary in a practical system to first define an acceptable risk level in order to determine the maximum demand that a particular committed system can meet. ; `0 f; b6 Y: A% ~! Z2)Consider, for example, that a risk of 0.001 is acceptable. If additional generation can be made available in System A within 1 hour, the required spinning reserve is only 30 MW and a demand of 170 MW can be supplied.% o$ |4 V! T" Z2 z# Z( ?
3) In practice an operator would use the PJM risk assessment method by adding, and therefore committing, one unit at a time from a merit order table until the unit commitment risk given by the generation model became equal to or less than the acceptable value for the demand level expected. 5 b8 W6 L; {4 p5 y
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原文2句的意思:假设系统允许的风险水平为0.1%。对系统A,若在1h内可以获得额外发电容量的支持,那么,A系统的旋备需求为30MW,可带负荷170MW。8 o3 k; O6 w3 K' ]* n4 q, Q e( }
! u- [+ {' P- d- D8 l我的疑问:1 [7 F, `& O$ _/ ]: w$ y
从表5.2可见,A系统停运容量大于30的累积概率=运行容量小于170的累积概率=0.0915%,即运行容量大于170概率99.9%,此情形下系统可以带负荷170MW,若还可以获得额外30MW旋备,系统可带负荷就应该是200MW。( j% y p6 ~: E# v
为何原文讲“170 MW can be supplied”? 1 B j9 i" W; F! X1 F; }( \1 v& y+ ~0 I3 v
3 X5 f. V8 K; q2 P6 \1 s' l: {