有源电力滤波器APF(active power filter)是一种动态抑制谐波、补偿无功的电力电子装置,能够对不同大小和频率的谐波进行快速实时跟踪补偿,有效降低电力系统的谐波含量。但APF长期处于高频通断的工作状态,造成较高的功率损耗和故障率,...有源电力滤波器APF(active power filter)是一种动态抑制谐波、补偿无功的电力电子装置,能够对不同大小和频率的谐波进行快速实时跟踪补偿,有效降低电力系统的谐波含量。但APF长期处于高频通断的工作状态,造成较高的功率损耗和故障率,降低了经济性和工作可靠性。针对高功损和高故障率的问题,分析传统滞环电流控制策略的不足,提出一种新型滞环电流控制策略,合理控制APF开关器件的通断,进而降低开关频率,同时提升谐波补偿效果,使APF工作可靠性和谐波补偿性能提高。最后仿真和实验结果验证了该控制策略的可行性与有效性。展开更多
With the widespread application of the computer and microelectronic technology in the industry,digitization becomes the inevitable developing trend of the hydraulic technology.Digitization of the hydraulic components ...With the widespread application of the computer and microelectronic technology in the industry,digitization becomes the inevitable developing trend of the hydraulic technology.Digitization of the hydraulic components is critical in the digital hydraulic technology.High-speed on-of valves(HSVs)which convert a train of input pulses into the fast and accurate switching between the on and of states belong to widely used basic digital hydraulic elements.In some ways,the characteristics of the HSVs determine the performance of the digital hydraulic systems.This paper discusses the development of HSVs and their applications.First,the HSVs with innovative structures which is classifed into direct drive valves and pilot operated valves are discussed,with the emphasis on their performance.Then,an overview of HSVs with intelligent materials is presented with considering of the switching frequency and fow capacity.Finally,the applications of the HSVs are reviewed,including digital hydraulic components with the integration of the HSVs and digital hydraulic systems controlled by the HSVs.展开更多
It is well known that the transient behaviors of the traditional adaptive control may be very poor in general, and that the adaptive control designed based on switching between multiple models is an intuitively appeal...It is well known that the transient behaviors of the traditional adaptive control may be very poor in general, and that the adaptive control designed based on switching between multiple models is an intuitively appealing and practically feasible approach to improve the transient performances. In this paper, we shall prove that for a typical class of linear systems disturbed by random noises, the multiple model based least-squares(LS) adaptive switching control is stable and convergent, and has the same convergence rate as that established for the standard least-squares-based self-tunning regulators. Moreover, the mixed case combining adaptive models with fixed models is also considered.展开更多
文摘有源电力滤波器APF(active power filter)是一种动态抑制谐波、补偿无功的电力电子装置,能够对不同大小和频率的谐波进行快速实时跟踪补偿,有效降低电力系统的谐波含量。但APF长期处于高频通断的工作状态,造成较高的功率损耗和故障率,降低了经济性和工作可靠性。针对高功损和高故障率的问题,分析传统滞环电流控制策略的不足,提出一种新型滞环电流控制策略,合理控制APF开关器件的通断,进而降低开关频率,同时提升谐波补偿效果,使APF工作可靠性和谐波补偿性能提高。最后仿真和实验结果验证了该控制策略的可行性与有效性。
基金Supported by Key Technologies Research and Development Program of China(Grant No.2019YFB2004502)National Natural Science Foundation of China(Grant Nos.51805350,51775362)Postdoctoral Science Foundation of China(Grant No.2019M651073).
文摘With the widespread application of the computer and microelectronic technology in the industry,digitization becomes the inevitable developing trend of the hydraulic technology.Digitization of the hydraulic components is critical in the digital hydraulic technology.High-speed on-of valves(HSVs)which convert a train of input pulses into the fast and accurate switching between the on and of states belong to widely used basic digital hydraulic elements.In some ways,the characteristics of the HSVs determine the performance of the digital hydraulic systems.This paper discusses the development of HSVs and their applications.First,the HSVs with innovative structures which is classifed into direct drive valves and pilot operated valves are discussed,with the emphasis on their performance.Then,an overview of HSVs with intelligent materials is presented with considering of the switching frequency and fow capacity.Finally,the applications of the HSVs are reviewed,including digital hydraulic components with the integration of the HSVs and digital hydraulic systems controlled by the HSVs.
基金This research is supportedby the National Natural Science Foundation of China.
文摘It is well known that the transient behaviors of the traditional adaptive control may be very poor in general, and that the adaptive control designed based on switching between multiple models is an intuitively appealing and practically feasible approach to improve the transient performances. In this paper, we shall prove that for a typical class of linear systems disturbed by random noises, the multiple model based least-squares(LS) adaptive switching control is stable and convergent, and has the same convergence rate as that established for the standard least-squares-based self-tunning regulators. Moreover, the mixed case combining adaptive models with fixed models is also considered.
