The fault recovery of VSC-HVDC transmission system is often influenced by many factors, such as the reactive power compensation characteristics of the inverter and the dynamic performance of DC controllers. In this pa...The fault recovery of VSC-HVDC transmission system is often influenced by many factors, such as the reactive power compensation characteristics of the inverter and the dynamic performance of DC controllers. In this paper, the PSCAD/ EMTDC simulation tool is used to study the dynamic recovery performance of VSC-HVDC system for several different var compensating devices in VSC-HVDC inverter-Fixed capacitor (FC), Static Var compensator (SVC), and Static synchronous compensator (STATCOM) when VSC-HVDC is subject to various faults, including three phase groundings, single phase grounding and three phase breakings. The result shows that the recovery process of the whole system will be slowed down due to its negative influence on the strength of AC power system with the application of SVC, while the STATCOM can improve VSC-HVDC recovery performance greatly for its advantages over other compensating devices in areas such as voltage support ability and DC power recovery.展开更多
Objective:To compare the difference in the clinical therapeutic effect on dysmenorrhea in the patients with adenomyosis between acupuncture and ibuprofen sustained release capsules.Methods:A total of 40 patients were ...Objective:To compare the difference in the clinical therapeutic effect on dysmenorrhea in the patients with adenomyosis between acupuncture and ibuprofen sustained release capsules.Methods:A total of 40 patients were randomized into an acupuncture group and an ibuprofen group,20 cases in each one.The treatment was given consecutively for 3 menstrual cycles and the follow-up lasted for 2 menstrual cycles.The score of visual analogue scale(VAS) at the most painful time during menstruation,menstrual flow,the score of COX menstrual symptom scale(CMSS) and the score of endometriosis health profile-5(EHP-5),as well as the patients’ satisfaction and acceptance were compared between the two groups.Results:Three menstrual cycles after treatment,the VAS score at the most painful time,menstrual flow,CMSS score and EHP-5 score were all lower than those before treatment in either group,with statistical significance(all P <0.05).Three menstrual cycles after treatment,compared with the ibuprofen group,in the acupuncture group,the VAS score at the most painful time was slightly higher(P> 0.05),the menstrual flow was lower(P> 0.05),CMSS score was higher(P <0.05) and EHP-5 was higher(P> 0.05).The score of the patients’ satisfaction and acceptance in the acupuncture group were all higher than the ibuprofen group(both P <0.05).In 2-menstrual cycles follow-up,the VAS score at the most painful time,menstrual flow,CMSS score and EHP-5 score in the acupuncture group were all lower than those in the ibuprofen group(all P <0.05).Conclusion:Acupuncture is effective for analgesia and symptom-relief and the long-term effect is superior to the oral administration of ibuprofen.展开更多
文摘The fault recovery of VSC-HVDC transmission system is often influenced by many factors, such as the reactive power compensation characteristics of the inverter and the dynamic performance of DC controllers. In this paper, the PSCAD/ EMTDC simulation tool is used to study the dynamic recovery performance of VSC-HVDC system for several different var compensating devices in VSC-HVDC inverter-Fixed capacitor (FC), Static Var compensator (SVC), and Static synchronous compensator (STATCOM) when VSC-HVDC is subject to various faults, including three phase groundings, single phase grounding and three phase breakings. The result shows that the recovery process of the whole system will be slowed down due to its negative influence on the strength of AC power system with the application of SVC, while the STATCOM can improve VSC-HVDC recovery performance greatly for its advantages over other compensating devices in areas such as voltage support ability and DC power recovery.
基金Supported by Special Scientific Research Project for the Basic Business Construction of National Clinical Trial of Traditional Chinese Medicine State Administration of Traditional Chinese Medicine:JDZX 2015063Anhui Provincial Key Specialty:Health Administration Secretariat[2016]No.680。
文摘Objective:To compare the difference in the clinical therapeutic effect on dysmenorrhea in the patients with adenomyosis between acupuncture and ibuprofen sustained release capsules.Methods:A total of 40 patients were randomized into an acupuncture group and an ibuprofen group,20 cases in each one.The treatment was given consecutively for 3 menstrual cycles and the follow-up lasted for 2 menstrual cycles.The score of visual analogue scale(VAS) at the most painful time during menstruation,menstrual flow,the score of COX menstrual symptom scale(CMSS) and the score of endometriosis health profile-5(EHP-5),as well as the patients’ satisfaction and acceptance were compared between the two groups.Results:Three menstrual cycles after treatment,the VAS score at the most painful time,menstrual flow,CMSS score and EHP-5 score were all lower than those before treatment in either group,with statistical significance(all P <0.05).Three menstrual cycles after treatment,compared with the ibuprofen group,in the acupuncture group,the VAS score at the most painful time was slightly higher(P> 0.05),the menstrual flow was lower(P> 0.05),CMSS score was higher(P <0.05) and EHP-5 was higher(P> 0.05).The score of the patients’ satisfaction and acceptance in the acupuncture group were all higher than the ibuprofen group(both P <0.05).In 2-menstrual cycles follow-up,the VAS score at the most painful time,menstrual flow,CMSS score and EHP-5 score in the acupuncture group were all lower than those in the ibuprofen group(all P <0.05).Conclusion:Acupuncture is effective for analgesia and symptom-relief and the long-term effect is superior to the oral administration of ibuprofen.
