Study On Optimal Configuration Of Reactive Power Compensation In Guangzhou Power Network Considering Voltage Stability

With the formation of "transmission from west to east" and national interconnection pattern,HVDC transmission has been widely used and developed in the whole country.When DC transmission is adopted,DC converter consumes a lot of reactive power.If the electrical coupling between DC converter stations is close and the receiving system is weak AC system,the transient voltage stability of weak AC system connected with DC system will be directly affected when DC blocking fault occurs in power grid.Voltage instability may occur.As a typical multi-infeed AC/DC hybrid receiving-end power grid,dynamic reactive power compensation is the best way to improve the voltage stability and security of the system,but the research on how to effectively and efficiently allocate dynamic reactive power is still not perfect.In this paper,the main functions of dynamic reactive power compensation device are systematically analyzed,and the advantages and disadvantages of SVC and STATCOM are compared in detail from the aspects of response time,harmonic generation,controllable performance and operation range,economy,etc.STATCOM device,as the best reactive power compensation device at present,is superior to SVC in harmonic characteristics,output characteristics,response speed and active power regulation ability,but its cost and control difficulty are at a disadvantage.It is worth further research and popularization.Aiming at the location problem of dynamic reactive power compensation devices in multi-feed AC/DC hybrid receiving-end power grid,two methods of selecting reactive power compensation devices are proposed based on CVM and VSF indices.Then a comprehensive method based on weighting two indices are given.Finally an example analysis and time domain simulation of Guangzhou Power Grid Summer2017 mode are carried out.The effectiveness and engineering practicability of the proposed method have been verified in large-scale AC/DC hybrid system simulation.Aiming at the capacity optimization problem of dynamic reactive power compensation devices in multi-infeed AC/DC hybrid receiving-end power grid,the risk assessment idea is introduced to quantify the risk of voltage collapse.Aiming at the maximum annual total cost difference before and after the installation of dynamic reactive power compensation devices,the capacity optimization model of dynamic reactive power compensation devices is proposed,and implied.Comprehensive optimization of safety,reliability and economy is included.A practical example of Guangzhou power grid is used to carry out dynamic simulation and optimization calculation.The results verify the rationality of the model and the effectiveness of the voltage support optimization scheme.The research results of this paper have important theoretical significance and practical value for promoting the development of dynamic voltage support theory of AC/DC hybrid receiving system in China.