Hdmr Applications On Probablistic Load Flow And Steady-state Security Regions

In recent years, probabilistic load flow and steady state security region getsmore and more attentions as the two important fields of the assessment andadjustment of the power system with the scale of the power flow's expansion andmore and more uncertain factors entering into electric power network. Searching forsimple and efficient computing methods has become the engineering research hotfield.The high dimensional model representation (HDMR) has the unique advantagein describing the relationship between the output and the multiple inputs of a certainsystem, with which the power network flow state variables and multiple bus inputsaccord well. The paper studied the principle and the modeling process of HDMR onthe base of literature review. It used the origin path chain information to find theloads and generators which influenced the branch power flow largly. It establishedthe HDMR model of the key branch power flow by using the developed GUI-HDMRsoftware. The branch power flow can be replaced by a combination of simplepolynomials by changing the order of inputs and the number of orthogonalpolynomials. The paper modified the HDMR model of the branch power flowcombined with sensitivity and the compensation methods in the case of the brokenbranch, which avoided the large-scale model reconstruction and saved lots of time.IEEE39system proves that HDMR model can match the power flow equations well.HDMR is applied to the power flow probabilistic assessment and adjustment inthis paper, where the HDMR relationship between transmission power of the keybranch and power sources and loads is established by the typical representativesamples. In place of the conventional power flow calculation method, HDMR isadopted to accomplish large-scale power flow calculations in the process of powerflow probabilistic assessment to improve the efficiency of the cumulativeprobability distribution generation of the key branch power flow and relatedcharacteristics calculation largely. Concerning the congestion of the key branchpower flow, a specific strategy of probabilistic adjustment is designed aiming atmaking full use of the global sensitivities provided by HDMR and considering theperformance index of energy conservation and emissions reduction as well. Atypical example shows that the application of HDRM can effectively enhance thecalculation efficiency of the power flow probabilistic assessment and theperformance of the key branch power flow probabilistic adjustment.Concerning the traditional AC power flow model occupying too much time andDC power flow model having larger error during the computing process of steadystate security regions, this paper insteaded AC or DC power flow model with HDMR model. This method not only keeps the fast calculation speed but alsoimproves the calculation accuracy. The paper also put forward a method ofcomputing security region of focused nodes' active power.Numerical examples showthat the application of HDMR model can improve the efficiency of steady statesecurity region' construction largely.This research work is supported by the National High Technology Research andDevelopment of China (863Program)(2011AA05A105) and the Major Projects onPlanning and Operation Control of Large Scale Grid of State Grid Corporation ofChina (SGCC-MPLG-023-2012).