Research On Static Voltage Stability Of Thevenin Equivalent Based On Generators Primary Power Balance

With the develop ment of socia l econo my and increasing of e lectric ity demand,the sca le of the power gr id becomes bigger, the vo ltage grade is higher andinterconnectedness is stronger, power syste m stability becomes more and moreprominent. The voltage stability proble m has been always a very important topic instable operation of power system.First, this paper introduces background and significance of the research, thedefinitio n, class ification and research methods of vo ltage stability, d iscusses themecha nis m of vo ltage collapse, summar ized analys is methods and the stabilityindexes on the static vo ltage stability in detail. In order to analyse load node vo ltagestability more intuitive and fast, the artic le adopts the analys is method of the veninequiva lent, that equiva lent fro m the portion of the power gr id apart fro m load nodes,and the n analyse simp lified c ircuit after the equiva lent to estimate the load nodesvoltage stability.In the voltage stab ility ana lys is based on theve nin equiva le nt, the trackingsolutio n of thevenin equiva lent parameters is the key to the analys is, it is the difficulty.Based on the venin equiva le nt, this paper presents a fast algorithm o f the veninequiva lent parameters. The algor ithm firstly obtained nodes vo ltage by power flowca lculation and sensitivity of vo ltage real part and imaginary part to active loadincreme nt by sensitivit y ana lys is, alse cons idering all ge nerators primary powerbala nce, and the n us ing the Ohm’s law o f the node and differentia l pr inc ip le toca lculate the thevenin equiva lent parameters. After obtaining the theve nin equivale ntcircuit of load node, we can use the vo ltage stability indexes to ana lyse node vo ltagestability. The method solving the lis ted equations not need to do iteration, and thecomputation process only needs the current trend data, is simple and quick.Fina lly, us ing s imulation and ana lys is of the IEEE-14nodes system a nd IEEE-57node system to ver ify the method, and summar ize that generator power balanceimpacts on The venin equivale nt parameters. By exa mp le ana lys is results s how thatwhen cons idering a ll generators primary power balance, the load nodes vo ltagestability are raised, and the change of the the ve nin equivale nt parameters anastomosedwith the theoretical ana lys is. It demonstrates the va lidity and the practicab ility of theproposed method in this paper, and can provide certain practica l applicatio n va lue for power dispatch department.