Research On The Method Of Upstream Tracing

Under the electricity market environment, the operating mode of power system will be changed from monopoly to open, more and more users want to be provided fair and equitable electricity delivery service by the power company. With the deepening of the marketization and the opening of the transmission system, it requires rapid and accurate determination of the actual use of the generators and loads on each transmission line. On the basis of the principle of "who use, who pays", according to the user’s actual use of the line, charge a fair and reasonable cost.From the results of past work, we can see that, downstream tracing and upstream tracing both can describe the process of power supply from the source to the load objectively. When do the economic accountings based on the results of power flow tracing, downstream tracing and upstream tracing may face different economic accounting results. In this paper, through the calculation and analysis of the combination of the power flow tracing and the economic accounting on the load and branch, verify the downstream tracing and upstream tracing two kinds of methods will produce different economic accounting results. Through the analysis, it is pointed out that the combination of upstream tracing and economic accounting is more coincidence with the physical and economic, provide help for the principle of "same network, same property and same price" to establish user cost price.The so-called load power supply path, refers to a transmission line supply power for lower loads, it can be considered that each load has an independent power supply path, and the power supply path is parallel in the transmission line, links the power that belongs to the same load of each branch in the network, formed the load power supply path. The impedance of each branch of the load power supply path is the equivalent impedance not the branch impedance, at this point, the power supply path contains only the power supply, the branch equivalent impedance and the load, thus get the independent reverse power supply path from the source to the load through the network.In this paper, two methods are used to carry out the upstream tracing of the power flow calculation results,one is current tracing the other is power tracing. A tracing method based on load power supply path separation is proposed, which accomplishes the current tracing scheme. Using the power transmission principle, accomplish the power tracing scheme. At the same time, the corresponding calculation procedure is given, thus provide the basis for the calculation of the network loss allocation and other practical issues, provided a new computational method for the research of the upstream tracing. Verified by IEEE 33-bus distribution network example, the results shows that under the single and multiple power source situation, the method can make load losses in the network get distinguished by loads. The loss of each load in each branch is in line with the branch loss in the calculation of the power flow, verify the accuracy of the tracing method.