(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: , D6 b; b- `3 _+ v" G! q6 u1) 6 M L. m- K- D* T9 NIt 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. 4 y! E9 \" @* J, T
2)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. 4 v; e1 l1 A8 n) @; ^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.# K! d, b. X$ v' u 5 B! W& H7 f' _# v6 b. v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。) C) ~, L% A) V- F2 W4 K1 ?0 u
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我的疑问: ! J0 T8 l- a+ q$ ~% m# x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。; H2 c. H% o" [) Y/ r7 O& e7 _
为何原文讲“170 MW can be supplied”? ) q8 e. I, d- [4 L- i, @2 o; C ' j3 x8 O' a9 c8 I; D0 M# i2 c) l 6 o) b# o0 y. I0 p5 O) I1 k