Research On Subsynchronous Oscillation Suppression Technology Of Power System Based On ADPSS

In order to solve the problem of low frequency oscillation in power system,power system stabilizer(PSS)is installed in the excitation system of large capacity generator set.With the wide application of PSS,the subsynchronous oscillation(SSO)becomes more and more significant.At the same time,with the rapid development of the power grid,it is necessary to establish a suitable power system simulation and test research platform in order to better solve the new technical problems of the current power system.Based on the above two aspects,this paper has carried out the research of power system subsynchronous oscillation suppression method,and through the advanced digital power system simulator(ADPSS)developed by China Electric Power Research Institute to build the simulation model and check the research method.Firstly,the development of power system digital simulation technology and power system subsynchronous oscillation analysis and suppression research is introduced.The research direction and project significance of this paper are clarified,and the ADPSS device is introduced comprehensively.Secondly,the coupled dynamic equations of shafting are decoupled,and a simple six coefficient linear model of shafting considering subsynchronous natural torsional vibration mode and low-frequency vibration engine is established.Using the UDM function of the ADPSS electromagnetic transient calculation platform(ETSDAC),the mathematical models of prime mover,governor and excitation system are established.Next,based on the six coefficient linear model of the engine shafting andthe method of moment decomposition,the non compensation hysteresis characteristics of IEEE ST1 A high initial response excitation system and IEEE AC1 A normal response excitation system are derived,and provides the basis for the design of PSS phase compensation mode and parameter adjustment of PSS-AVR excitation system with compensation frequency characteristics.After that,it studies the influence of PSS1 A power system stabilizer on subsynchronous oscillation in three different phase compensation modes.Frequency characteristics of PSS-AVR based on three methods,it is judged that PSS1 A with delay compensation and reverse phase compensation as(35)? input signal can provide positive damping for the low-frequency segment and avoid the influence of subsynchronous signal.ETSDAC is used to analyze PSS1 A to suppress the low-frequency oscillation,The results show that it is reasonable to study the influence of subsynchronous oscillation.Finally,the influence of the parameter adjustment of acceleration power PSS on the subsynchronous oscillation is studied.Because the phase compensation degree of the subsynchronous signal in PSS2 B is mainly determined by the torsional vibration filter,according to the hysteresis characteristic of ST1 A excitation system and the waiting compensation characteristic of torsional vibration filter,the parameter adjustment of the power matching coefficient and the time constant of torsional vibration filter in PSS2 B system is carried out by analyzing The phase frequency characteristics of PSS-AVR under different parameters are selected,which can suppress or eliminate the subsynchronous torsional vibration signal better without affecting the phase of the low-frequency band.ETSDAC is used to analyze the torsional vibration suppression effect of PSS2 B on the mass blocks,and the effectiveness of PSS2 B to suppress the subsynchronous vibration after parameter adjustment is verified.