A Method Of Electric Transmission Cost Accounting Based On Power Energy

Transmission cost represents the cost of transporting electricity power during the transmission link for grid operation companies. Transmission companies should seek the most effective and reasonable approach to cost accounting actively, in order to better grasp the operating costs, improve the management level and to adapt to the market economy. Correctness of the method of cost accounting means significant to the fairness, justice and openness of power system in the market environment.This paper represents an accounting method based on electricity and concerns about the whole process of transmission. That could avoid the multi-section cumulative accounting due to the fluctuations happened in the system from time to time. Since power flow is the fundamental of economic accounting and has one-to-one relationship to it. The changing transmission process should obtain its equivalent power flow through one calculation. Without changing the method of power flow calculation, electrical parameters must undergo appropriate treatment in order to reflect the characteristics of the fluctuations within the entire time.The equivalent conversion method meets the demand of both energy conversation and basic circuit laws. By analysis of First Order Circuit, it is validated that under dynamic conditions the instantaneous power on the resistance containing damping component. That would make the average power in each period different. Considering of damping component, the period of dynamic circuit is infinity and average power during that time would be accurate and can reflect the circuit truly condition. Weighted average is used to calculate power in multiple periods. Error between multiple-periods average power and power under infinity time is controlled within the range allowed by power system. When converting the electrical parameters, RMS Method is used to obtain voltage and current rms; multiple-periods-average-power method is used to obtain active power. Calculation time of those parameters should be exactly the same with each other. Finally reactive power is achieved by apparent power.The whole process power flow can be obtained after equivalent parameters are calculated, and that is also the basic of accounting method based on electricity. Power-based accounting method is processed into electricity-based method.In case analysis the IEEE9system is used to calculate power flow and economic cost accounting. First it is verified that the equivalent conversion method is correct so that the two power flow happened between dynamic in system can be equaled to a whole process one. And they meet the demand of energy conversation. Second the transmission cost accounting is calculated after the above verification. And it is certified that the accounting method based on electricity can equal to the multiple-section power accounting method.