Available Transfer Capability Under The Condition Of Power Market Environment And The Analyze On Sensitivity

In power market environment, Available Transfer Capability of power system is important index of transfer capability and system security. ATC refers to the maximum transfer capability of transmission network to power market. With development of power market, bilateral trade increase greatly. Study on ATC is a significant topic with much attention. Firstly the full presentation of historic and recent research achievement of ATC is given. Definition about calculation of ATC is introduced, including definition of Total Transfer Capability, Transmission Reliability Margin, Capacity Benefit Margin etc and some uncertainty factor. Also, several typical ATC calculating methods on the basis of determinable model are compared. Then a new method of calculating ATC that actual node power is different from the base flow power is given.Normally, the available transfer capability of the study transfer is obtained for a given base power flow. In practical power system operation, it is very common that actual node power is different from the base flow power. Therefore, actual available transfer capability is not equal to the available transfer capability calculated by using the base flow. If once the node power changed, the available transfer capability calculation is carried out, a lot times of calculation will be needed, which will cost a lot of computation time. Based on the processing of the available transfer capability by using distribution factors, the sensitivity of available transfer capability with respect to the node power is proposed. The sensitivity can be used to estimate the available transfer capability of the study transfer and to predict the change region of the available transfer capability when the node power changed. It's indicated that this method is quick with a relatively exact, utilitarian and explicit calculating results. Also, because of such quick speed, sensitivity analyzing way can be widely used to avoid repetitive calculating of ATC. In fact, it's not an independent calculating way based on ATC in a basic state on grounds of dc trend calculating of distribution factors.