Abstract A closed-loop fault detection problem is investigated for the full-envelope flight vehicle with measurement delays, where the flight dynamics are modeled as a switched system with delayed feedback signals. Th...Abstract A closed-loop fault detection problem is investigated for the full-envelope flight vehicle with measurement delays, where the flight dynamics are modeled as a switched system with delayed feedback signals. The mode-dependent observer-based fault detection filters and state estimation feedback controllers are derived by considering the delays＇ impact on the control system and fault detection system simultaneously. Then, considering updating lags of the controllers/filters＇ switching signals which are introduced by the delayed measurement of altitude and Mach number, an asynchronous H analysis method is proposed and the system model is further augmented to be an asynchronously switched time-delay system. Also, the global stability and desired performance of the augmented system are guaranteed by combining the switched delay-dependent Lyapunov Krasovskii functional method with the average dwell time method （ADT）, and the delaydependent existing conditions for the controllers and fault detection filters are obtained in the form of the linear matrix inequalities （LMIs）, Finally, numerical example based on the hypersonic vehicles and highly maneuverable technology （HiMAT） vehicle is given to demonstrate the merits of the proposed method.展开更多
In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed i...In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed in this paper, together with its hardware structure and software flow chart. Fault waveform regenerator mainly depends on its power amplifiers (PAs) to regenerate the fault waveforms recorded by digital fault recorder (DFR). To counteract the PA’s inherent nonlinear distortions, a digital closed-loop modification technique that is different from the predistortion technique is conceived. And the experimental results verify the effectiveness of the fault waveform regenerator based on the digital closed-loop modification technique.展开更多
针对DP-2或DP-3级船舶中压闭合母排电力系统高冗余性和容错性的保护需求,提出一种兼顾快速性与可靠性的选择性保护方案,旨在解决单点故障叠加隐性故障下的故障隔离难题,确保失电区域不超过动力定位系统最大允许失效范围,通常为一段中压...针对DP-2或DP-3级船舶中压闭合母排电力系统高冗余性和容错性的保护需求,提出一种兼顾快速性与可靠性的选择性保护方案,旨在解决单点故障叠加隐性故障下的故障隔离难题,确保失电区域不超过动力定位系统最大允许失效范围,通常为一段中压主母排。基于闭合母排电力系统运行特性,将中压系统中每段主母排划分为发电机、母排、负载馈线及母联电缆4类保护区域,通过差动保护与方向纵联保护的协同配置构建主保护或后备保护两层保护。依托典型DP-2级船舶的6.6 k V闭合母排架构,搭建了包含一段主母排上各类综合继电保护装置硬件与数字实时仿真系统的硬件在环(HIL)测试平台,在4类区域完成单点故障叠加隐性故障的8种运行工况的模拟测试,分别测试4类区域上主、后备保护的有效性,结果表明保护系统在故障电流水平动态变化的各类工况下均可正确动作,验证了所提保护方案的协调性、可靠性和快速性。展开更多
The paper presents a new modeling method applied to fault diagnosis for constant linear closed-loop system by taking the impulse response series as the system model, and provides the calculation process of the method ...The paper presents a new modeling method applied to fault diagnosis for constant linear closed-loop system by taking the impulse response series as the system model, and provides the calculation process of the method and output of model. The high frequency part of the pulse series, in the method, is reversed so as not to lose the frequency information of the pulse series in its transfer function. On the other hand, the method can also avoid the disadvantage that the learning results of neural network are uncertain every time. In the last part, the application with random disturbance of digital simulation and practical system shows that the modeling method is high accurate and suitable to be applied in fault diagnosis area.展开更多
基金supported by the National Natural Science Foundation of China(Nos.61074027,61273083)
文摘Abstract A closed-loop fault detection problem is investigated for the full-envelope flight vehicle with measurement delays, where the flight dynamics are modeled as a switched system with delayed feedback signals. The mode-dependent observer-based fault detection filters and state estimation feedback controllers are derived by considering the delays＇ impact on the control system and fault detection system simultaneously. Then, considering updating lags of the controllers/filters＇ switching signals which are introduced by the delayed measurement of altitude and Mach number, an asynchronous H analysis method is proposed and the system model is further augmented to be an asynchronously switched time-delay system. Also, the global stability and desired performance of the augmented system are guaranteed by combining the switched delay-dependent Lyapunov Krasovskii functional method with the average dwell time method （ADT）, and the delaydependent existing conditions for the controllers and fault detection filters are obtained in the form of the linear matrix inequalities （LMIs）, Finally, numerical example based on the hypersonic vehicles and highly maneuverable technology （HiMAT） vehicle is given to demonstrate the merits of the proposed method.
文摘In order to provide a novel and more effective alternative to the commonly used relay protection testing device that outputs only the sinusoidal testing signals, the concept of fault waveform regenerator is proposed in this paper, together with its hardware structure and software flow chart. Fault waveform regenerator mainly depends on its power amplifiers (PAs) to regenerate the fault waveforms recorded by digital fault recorder (DFR). To counteract the PA’s inherent nonlinear distortions, a digital closed-loop modification technique that is different from the predistortion technique is conceived. And the experimental results verify the effectiveness of the fault waveform regenerator based on the digital closed-loop modification technique.
文摘针对DP-2或DP-3级船舶中压闭合母排电力系统高冗余性和容错性的保护需求,提出一种兼顾快速性与可靠性的选择性保护方案,旨在解决单点故障叠加隐性故障下的故障隔离难题,确保失电区域不超过动力定位系统最大允许失效范围,通常为一段中压主母排。基于闭合母排电力系统运行特性,将中压系统中每段主母排划分为发电机、母排、负载馈线及母联电缆4类保护区域,通过差动保护与方向纵联保护的协同配置构建主保护或后备保护两层保护。依托典型DP-2级船舶的6.6 k V闭合母排架构,搭建了包含一段主母排上各类综合继电保护装置硬件与数字实时仿真系统的硬件在环(HIL)测试平台,在4类区域完成单点故障叠加隐性故障的8种运行工况的模拟测试,分别测试4类区域上主、后备保护的有效性,结果表明保护系统在故障电流水平动态变化的各类工况下均可正确动作,验证了所提保护方案的协调性、可靠性和快速性。
文摘The paper presents a new modeling method applied to fault diagnosis for constant linear closed-loop system by taking the impulse response series as the system model, and provides the calculation process of the method and output of model. The high frequency part of the pulse series, in the method, is reversed so as not to lose the frequency information of the pulse series in its transfer function. On the other hand, the method can also avoid the disadvantage that the learning results of neural network are uncertain every time. In the last part, the application with random disturbance of digital simulation and practical system shows that the modeling method is high accurate and suitable to be applied in fault diagnosis area.
