Rapid Method Of Calculating Theoretical Line Loss Of The Transmission System

The Rate of net loss is one synthesis mark of technology and economy for a power corporation. So the study of "Net Loss Statistic" (NLS) is one task of consequence in the domain of electric.The aim of NLS is to calculate the real-time running net loss. The calculation relate to the parameters of power system. If the state of system at any time were gained precisely in the given period, net loss could be calculated. However such calculation can't be done because of the characteristics of power system. In our country, the method of NLS using now is called Loss Equivalent Analysis (LEA). LEA means by calculating the net power flow in one typical day( week, month or year)to estimate the net loss. It is also named Theory Net Loss Calculation. By using LEA, we can not only get the quantity of the net loss, but evaluate the running model of grid from the info of net power and get the splendid result. Nevertheless The obvious defect of LEA is that the time used in calculating the power flow is too long, and the parameters in calculating need a high degree of accuracy or the result cannot be convergence.A fast method of calculating the net loss (FCNL) using incremental transmission losses (ITL) based on power flow calculation has been proposed in this paper. To get the result of net loss at every point more fast, this method revises the net loss of typical day to reduce the times of power flow calculation (PFC). This paper takes IEEE-39 for example to explain the method. By contrasting the two result of FCNL and PFC, it can be found that the injecting power of some point has the strongly nonlinear relationship with the Net Loss Power, so the compensating-net-loss of such points would be incorrect. In this paper, two methods are proposed to solve this problem. One is using the 2^nd order deviation to correct the result based on the ITL. Another one is using multi-period-of-time-calculation in some points whose injecting power changes widely or property has been changed in some period of time. The result shows that the new algorithms are high efficiency and feasible.This paper takes power grid of Shandong province for example to check the practicability of FCNL. According to the generating power, load and running-mode of the grid, FCNL uses different correcting methods to calculate the transmission net loss . By compares the results, we get the conductions of FCNL when calculating the large scale bulk transmission system.The system we used when calculating the net loss is a new independent platform. Referring to many other software of net-loss-analyses, The platform improves the data module, the graph module and many other modules. When calculating the net loss of Shandong province, it deals with the data conveniently and gathers the net loss info automatically. In this paper, The FCNL has been added to the platform as a module to enrich the functions of it and it also boosts the commercial research of FCNL.