(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: : L6 t1 l w9 ? f* R3 y" ? }1)" L8 L2 Q" `2 R# K% o 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. d6 v+ T: O, d
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. ( ]# Q2 ~4 d; A. Q8 W) U3) 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.. d5 ^" A: K. Q/ _ e
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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。 ( O/ y b3 i2 V) w1 Z 5 B& L* n" W6 V8 M+ E我的疑问:( ?: }" X( D. {; n$ t
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。 ; d/ F+ O7 i) C3 r为何原文讲“170 MW can be supplied”?$ D/ o9 z# P9 R, k8 [
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