Low temperature plasma was used to treat sludge,and the effects of discharge time on the content of different forms of heavy metals in the sludge were studied. The results showed that Cu and Zn content in the domestic...Low temperature plasma was used to treat sludge,and the effects of discharge time on the content of different forms of heavy metals in the sludge were studied. The results showed that Cu and Zn content in the domestic sludge could basically meet the requirements of GB 4284-2018,GB/T 23486-2009,CJ/T 362-2011 and CJ/T 309-2009. There were big differences between different forms of the heavy metals. According to the proportions of different forms of Cu in the sludge,different forms of Cu are arranged as follows: organic state > carbonate bound state> residual state > exchangeable state > iron-manganese oxidation state,and Cu mainly existed in an organic state. Various forms of Zn are arranged in order of the proportion as follows: iron-manganese oxidation state > residual state > carbonate bound state > exchangeable state > organic state,and Zn mainly existed in an iron-manganese oxidation state. After the treatment of sludge by low temperature plasma,the content of exchangeable Cu and Zn in the sludge increased,while the content and proportion of residual Cu and Zn all reduced.展开更多
Introduction:With the development of flexible HVDC technology,the fault diagnosis of MMC-HVDC becomes a new research direction.Based on the fault diagnosis theory,this paper proposes a robust fault diagnosis method to...Introduction:With the development of flexible HVDC technology,the fault diagnosis of MMC-HVDC becomes a new research direction.Based on the fault diagnosis theory,this paper proposes a robust fault diagnosis method to study the fault diagnosis problem of MMC-HVDC systems.Methods:By optimizing the gain matrix in the fault observer,fault detection with good sensitivity and robustness to disturbance is achieved.In the MMC-HVDC system,because of the inherently uncertain system and the presence of various random disturbances,the study of robust fault diagnosis method is particularly important.Results:Simulation studies during various AC faults have been carried out based on a 61-level MMC-HVDC mathematical model.The results validate the feasibility and effectiveness of the proposed fault diagnosis method.Conclusions:So this fault diagnosis method can be further applied to the actual project,to quickly achieve system fault diagnosis and accurately complete fault identification.展开更多
基金Supported by International Science&Technology Cooperation Program of China(2015DFR70390)Science and Technology Platform and Base Construction Project of Chongqing City,China(cstc2014gjhz20001)Science and Technology Planning Project of Chongqing City,China(cstc2011pt-gc80019)
文摘Low temperature plasma was used to treat sludge,and the effects of discharge time on the content of different forms of heavy metals in the sludge were studied. The results showed that Cu and Zn content in the domestic sludge could basically meet the requirements of GB 4284-2018,GB/T 23486-2009,CJ/T 362-2011 and CJ/T 309-2009. There were big differences between different forms of the heavy metals. According to the proportions of different forms of Cu in the sludge,different forms of Cu are arranged as follows: organic state > carbonate bound state> residual state > exchangeable state > iron-manganese oxidation state,and Cu mainly existed in an organic state. Various forms of Zn are arranged in order of the proportion as follows: iron-manganese oxidation state > residual state > carbonate bound state > exchangeable state > organic state,and Zn mainly existed in an iron-manganese oxidation state. After the treatment of sludge by low temperature plasma,the content of exchangeable Cu and Zn in the sludge increased,while the content and proportion of residual Cu and Zn all reduced.
文摘Introduction:With the development of flexible HVDC technology,the fault diagnosis of MMC-HVDC becomes a new research direction.Based on the fault diagnosis theory,this paper proposes a robust fault diagnosis method to study the fault diagnosis problem of MMC-HVDC systems.Methods:By optimizing the gain matrix in the fault observer,fault detection with good sensitivity and robustness to disturbance is achieved.In the MMC-HVDC system,because of the inherently uncertain system and the presence of various random disturbances,the study of robust fault diagnosis method is particularly important.Results:Simulation studies during various AC faults have been carried out based on a 61-level MMC-HVDC mathematical model.The results validate the feasibility and effectiveness of the proposed fault diagnosis method.Conclusions:So this fault diagnosis method can be further applied to the actual project,to quickly achieve system fault diagnosis and accurately complete fault identification.
