The Analysis Of Electric System Transient Stability Of The Offshore Oil Platform

With the increasing amount of offshore oil exploited and number of offshoreblocks and platforms, the scale of plateform and load rises rapidly. Therefore, thescale of electric power system is becoming enormous especially when the connectionbetween different blocks through undersea cables is becoming frequent.With morecomplicated circumstances, offshore electric system is easily affected by big faults.Compared with land electric system, offshore system has low voltages and capacities.Its power is supplied just on the one side and there is no autoreclosure device on it.These make offshore system can’t resist big faults and has unstable power supply.Offshore electric system has a complex transient process, a small time constant and aquick decay process. All these lead to a unstable system. As a result, it is necessary tostudy tansient stability of electric system of offshore platform, which is of benefittoimprove safe operation of electric system, to secureconsistent electricity and toreduce the loss of lose power.This paper take time domain method to study tansient stability of an offshoreplatform based on electrical system simulation software EDSA. First, we build amathematical model and input datas for each electric element,and based on powerflow and short circuit analysis we set four different faults of three phases short circuit.Then we do tansient stability calculation and compare these different results. Second,we change the way of operation to observe how different way will influencetansientstability of electric system under the same fault. We choose more complexe’qchanging model and double windings model instead of constant model andclassical model to do simulation analyses and obtain more accurate and actual results.Change model datas so that we can observe the influence in tansient stability ofelectric systembecause of the change. Finally, we suggest a better protection planrefered to relay protection setting report and use EDSA to prove its better effects ontansient stability of electric system.