Research On Harmonic Characteristics Of HVDC Transmission System Based On Absorption And Parallel Capacitor Commutation

At present,the current situation of China is that the energy distribution and economic development are very asymmetric.In the eastern coastal areas of the eco-nomic development and prosperity,there is no corresponding power resources,but the surplus capacity can appear in the backward areas of the western economy.In order to solve this problem,the technology of high voltage direct current transmission came into being.It is used to solve the development strategy of "power transmission from west to East" and "nationwide interconnection".With the zero change of UHV and UHVDC transmission projects in China,more than more than 10 HVDC projects have been successfully built up to now.In the process of project construction and actual operation,there are many urgent technical problems to be solved.In this paper,the research work of the smart grid joint fund guide(nine)the 1."transmission and transformation equipment noise characteristics and the suppression method" in the power environment and the disaster prevention field is carried out,which has great theoretical and practical value.Firstly,based on the current state of China’s power grid,the necessity of HVDC development and its development in China are expounded,and the characteristics of HVDC transmission technology are analyzed in detail,and the new development of commutation technology is summarized,including power grid commutation converter,forced commutation converter and induction filter exchange.The basic structure,principle and research status of the phase commutation device are presented.Based on the existing topology,a commutation converter(ASCCC)based on absorption and shunt capacitance commutation is proposed.The concept harm and analysis method of harmonics in DC transmission system are introduced,and the harmonic characteristics of characteristic harmonics and non characteristic harmonics in AC and DC side of DC transmission system are analyzed in detail,and the calculation formula is given.Besides,the influence of harmonics on absorption and joint capacitance is also ana-lyzed.Then the connection mode of ASCCC and the topology and system composition of the ASCCC Based HVDC system system are introduced,and the essential differ-ence between the new HVDC transmission system and the conventional LCC-HVDC is compared and analyzed.According to the topology structure,the working principle of ASCCC is introduced in detail.The influence of ASC and transformer leakage re-actance on commutation valve commutation process is theoretically derived and cal-culated.Based on the previous theory,the three technical characteristics of ASCCC are obtained and the theoretical analysis is carried out.Finally,based on the simulation modeling of the Three Gorges Guangdong ±500kV DC transmission project,the voltage and current waveform of the converter station is analyzed and compared with the conventional and new HVDC converter station,and the experimental verification of the prototype of the new converter transformer is given.The experimental platform and system parameters are introduced,and the measured waves are introduced.The shape and data draw the following con-clusions:the harmonic suppression effect of the absorption and shunt capacitor com-mutator is remarkable.Due to the shunt capacitor shunt,the harmonics are absorbed most of the converter transformer net side,greatly reducing the influence of the har-monic to the loss and noise of the converter transformer,and improving the voltage and current waveform of the valve side.At the same time,the commutation principle of the converter is changed from mechanism to commutation,which makes the com-mutation more stable and reliable,thus enhancing the stability of the operation of the HVDC transmission system.Firstly,based on the current state of China’s power grid,the necessity of HVDC development and its development in China are expounded,and the characteristics of HVDC transmission technology are analyzed in detail,and the new development of commutation technology is summarized,including power grid commutation converter,forced commutation converter and induction filter exchange.The basic structure,principle and research status of the phase commutation device are presented.Based on the existing topology,a commutation converter(ASCCC)based on absorption and shunt capacitance commutation is proposed.The concept harm and analysis method of harmonics in DC transmission system are introduced,and the harmonic characteristics of characteristic harmonics and non characteristic harmonics in the AC and DC side of the DC transmission system are analyzed in detail,and the calculation formula is given.Besides,the influence of harmonic on the loss and noise of the change rheology press and the harmonic are also analyzed.The influence of wave on absorption and shunt capacitor.