Research On Transmission Loss Allocation Theory And Application

Under transmission open access, allocating transmission losses fairly and reasonably becomes an issue that market members generally pay attention to. In respect of theory, three contents are researched. These contents include the proposed power flow tracing methods, transmission loss allocation of bilateral transaction and transmission loss allocation method in pool/bilateral transaction framework. In respect of practicability, the practicability of transmission loss allocation is researched combined with wheeling loss allocation of Ji Lin province electricity market. Loss amendment of generation bid is researched and at the same time northeast region electricity market is used as an object.The three proposed power flow tracing methods are compared. It is clarified that the power flow can not be traced exactly since the information of active and reactive flow used to allocate power losses can not be offered in directed active or reactive power flow graph simultaneously. The power loss vector diagram is proposed and used as a tool to investigate the real and imaginary currents tracing method. Results show that in some cases the loss allocating results by current tracing method are not reasonable. Simulations verify this phenomenon. It is also clarified that even if the loss allocating rule which considers the interaction between active and reactive power is used, the power flow can not be exactly traced directly when active power flow path is different from that of reactive power flow. The proposed iterative method can solve the problem.The expression of cross interaction matrix is presented to interaction of bilateral transactions. Interacting degree is quantitatively analyzed according to matrix element. Counter flow problem caused by bilateral transaction is qualitatively analyzed by means of cross interaction matrix. The notion of apparent counter flow, quasi-counter flow and hidden counter flow is presented and their criterion is also given. A loss allocation method based on cross interaction matrix is presented in this paper and allocation results reflect interaction of bilateral transactions.A transmission loss allocation method based on the power flow tracing in a pool/bilateraltransaction framework is proposed. Transmission loss can be allocated to each bilateral transaction according to the power flow tracing results. The method solves the problem that previous power flow tracing methods can not deal with bilateral transactions.The notion of average electricity data is introduced to loss allocation combined with peculiarity of practical power system. A loss allocation scheme based on average electricity data is presented in the foundation of above analysis. This scheme avoids some problems. These problems include great quantity of calculation and long calculating time. All problems are caused by collecting nodal power data repeatedly. A series of practicability measures is adopted in the course of applying power flow tracing. These measures deal with several problems. Corresponding practicability research is applied to wheeling loss allocation of Ji Lin province electricity market.In accordance with loss amendment of generation bid under unbundling generation region market, it is pointed that the essence of loss amendment of generation bid is transmission loss allocation. Two losses amendable methods are compared combined with operating rule of northeast region electricity market and basic requirements of practical algorithm and at the same time simplified northeast electrical grid is used as an object. Two losses amendable methods are power flow perturbing method and power flow tracing method. The two methods are researched comparatively from following four respects. They are loss optimization direction, loss amendable coefficient, amending dynamics of generation bid, balance of loss cost. It is also pointed to the problem of power flow perturbing method through analysis. It is cleared that power flow tracing method is suitable for loss amendment of generation bid during initial stage of northeast region el...