The valve side of the converter in the high‐voltage direct current is subjected to mixed voltages such as composite AC&DC voltage.In this study,the effects of the homo-geneity of electric field on breakdown volta...The valve side of the converter in the high‐voltage direct current is subjected to mixed voltages such as composite AC&DC voltage.In this study,the effects of the homo-geneity of electric field on breakdown voltage were investigated for different�DC component amplitudes of the composite voltage.The field efficiency factor was calcu-lated using mean and maximum field strengths for all of them.Variation of breakdown voltage of air was examined under the composite AC&DC voltage for different ratios�DC.As one result of the study,the breakdown occurs at the positive half‐wave of the AC voltage despite−DC voltage being applied due to positive corona discharge pulses.This breakdown point is named as the polarity change point.The breakdown voltage increases with the decrease of DC voltage component up to polarity change point in non‐uniform electric field.In less uniform electric field,the AC breakdown voltage was measured slightly higher than the DC breakdown voltage.In less uniform electric field,as the ratio of the applied AC voltage to DC voltage increases,the breakdown voltage gradually approaches the AC breakdown voltage.This result is similar to the result ob-tained for the+DC component in non‐uniform electric field experiments.展开更多
基金the publication costs by the Open Access Publication Fund of the Technische Universität Ilme-nau.The authors would like to thank TU Ilmenau Center for Energy Technology of the Thuringian Energy Research Insti-tute for the use of the High Voltage Diagnostic Laboratory,the Technological Research Council of Turkey(TUBITAK)for 2214/A Ph.D.Scholarship Program and Marmara University Scientific Research Projects Commission for its support in the form of a Grant(FEN‐A‐130219‐0031).
文摘The valve side of the converter in the high‐voltage direct current is subjected to mixed voltages such as composite AC&DC voltage.In this study,the effects of the homo-geneity of electric field on breakdown voltage were investigated for different�DC component amplitudes of the composite voltage.The field efficiency factor was calcu-lated using mean and maximum field strengths for all of them.Variation of breakdown voltage of air was examined under the composite AC&DC voltage for different ratios�DC.As one result of the study,the breakdown occurs at the positive half‐wave of the AC voltage despite−DC voltage being applied due to positive corona discharge pulses.This breakdown point is named as the polarity change point.The breakdown voltage increases with the decrease of DC voltage component up to polarity change point in non‐uniform electric field.In less uniform electric field,the AC breakdown voltage was measured slightly higher than the DC breakdown voltage.In less uniform electric field,as the ratio of the applied AC voltage to DC voltage increases,the breakdown voltage gradually approaches the AC breakdown voltage.This result is similar to the result ob-tained for the+DC component in non‐uniform electric field experiments.
