This paper provides a new method for designing the load of transmitters switch components on provincial radar test platform. Based on the calculation of the specific parameters related to the actual charge switch comp...This paper provides a new method for designing the load of transmitters switch components on provincial radar test platform. Based on the calculation of the specific parameters related to the actual charge switch components, the load-related data model is obtained, the simulation is carried out, and the results are consistent with the actual test results. Through the theoretical numerical analysis of the load of the charging switch components of the transmitter device in the new generation of weather radar maintenance test platform, radar maintenance personnel at all levels can deepen the thorough understanding of the CINRAD/SA transmitter and have some enlightenment and improvement on the maintenance guarantee ability of the new generation of weather radar.展开更多
Analyzes the mechanism of overvoltage when contactless tap changer switch which is applied in distributing transformer converted directly.When the device convert the tap off,it employs the way that the SSR is switche...Analyzes the mechanism of overvoltage when contactless tap changer switch which is applied in distributing transformer converted directly.When the device convert the tap off,it employs the way that the SSR is switched on when voltage through zero and switched off when current through zero.But in the experiment we found that overvoltage will occur in the process of changing tap changer.The paper illustrates the mechanism of overvoltage in theory by analyzing the equivalent circuit and using analytic method of transition process.展开更多
In this paper, we focus on the estimation of time delays caused by adversaries in the sensing loop (SL). Based on the literature review, time delay switch (TDS) attacks could make any control system, in particular a p...In this paper, we focus on the estimation of time delays caused by adversaries in the sensing loop (SL). Based on the literature review, time delay switch (TDS) attacks could make any control system, in particular a power control system, unstable. Therefore, future smart grids will have to use advanced methods to provide better situational awareness of power grid states keeping smart grids reliable and safe from TDS attacks. Here, we introduce a simple method for preventing time delay switch attack on networked control systems. The method relies on an estimator that will estimate and track time delays introduced by an adversary. Knowing the maximum tolerable time delay of the plant’s optimal controller for which the plant remains stable, a time-delay detector issues an alarm signal when the estimated time delay is larger than the minimum one and directs the system to alarm state. In an alarm state, the plant operates under the control of an emergency controller that is local to the plant and remains in this mode until the networked control system state is restored. This method is an inexpensive and simple way to guarantee that an industrial control system remains stable and secure.展开更多
文中提出一种集成可变母线的宽输入范围双有源全桥(dual active full bridge,DAB)变换器。与传统DAB变换器不同,所提变换器本质上是四开关Buck-Boost变换器与DAB变换器原边全桥进行复用,从而实现可变母线的构造与集成。通过调节可变母...文中提出一种集成可变母线的宽输入范围双有源全桥(dual active full bridge,DAB)变换器。与传统DAB变换器不同,所提变换器本质上是四开关Buck-Boost变换器与DAB变换器原边全桥进行复用,从而实现可变母线的构造与集成。通过调节可变母线的电压,可以在很宽的电压调节范围内实现电压匹配。同时辅助电感仅处理总功率的一部分并以连续导通模式工作,从而降低损耗并减小尺寸。所有开关均被证明可实现理论上的全负载范围零电压开关操作。此外,提出一种混合脉宽调制加相移调制控制策略来实现电压匹配控制并调节功率流;详细介绍其工作原理、工作特点和参数设计原则;最后,搭建一台1 k W实验室样机来验证理论分析。展开更多
文摘This paper provides a new method for designing the load of transmitters switch components on provincial radar test platform. Based on the calculation of the specific parameters related to the actual charge switch components, the load-related data model is obtained, the simulation is carried out, and the results are consistent with the actual test results. Through the theoretical numerical analysis of the load of the charging switch components of the transmitter device in the new generation of weather radar maintenance test platform, radar maintenance personnel at all levels can deepen the thorough understanding of the CINRAD/SA transmitter and have some enlightenment and improvement on the maintenance guarantee ability of the new generation of weather radar.
基金Harbin science an technology officecontract num ber is 0 0 112 110 98
文摘Analyzes the mechanism of overvoltage when contactless tap changer switch which is applied in distributing transformer converted directly.When the device convert the tap off,it employs the way that the SSR is switched on when voltage through zero and switched off when current through zero.But in the experiment we found that overvoltage will occur in the process of changing tap changer.The paper illustrates the mechanism of overvoltage in theory by analyzing the equivalent circuit and using analytic method of transition process.
文摘In this paper, we focus on the estimation of time delays caused by adversaries in the sensing loop (SL). Based on the literature review, time delay switch (TDS) attacks could make any control system, in particular a power control system, unstable. Therefore, future smart grids will have to use advanced methods to provide better situational awareness of power grid states keeping smart grids reliable and safe from TDS attacks. Here, we introduce a simple method for preventing time delay switch attack on networked control systems. The method relies on an estimator that will estimate and track time delays introduced by an adversary. Knowing the maximum tolerable time delay of the plant’s optimal controller for which the plant remains stable, a time-delay detector issues an alarm signal when the estimated time delay is larger than the minimum one and directs the system to alarm state. In an alarm state, the plant operates under the control of an emergency controller that is local to the plant and remains in this mode until the networked control system state is restored. This method is an inexpensive and simple way to guarantee that an industrial control system remains stable and secure.
文摘文中提出一种集成可变母线的宽输入范围双有源全桥(dual active full bridge,DAB)变换器。与传统DAB变换器不同,所提变换器本质上是四开关Buck-Boost变换器与DAB变换器原边全桥进行复用,从而实现可变母线的构造与集成。通过调节可变母线的电压,可以在很宽的电压调节范围内实现电压匹配。同时辅助电感仅处理总功率的一部分并以连续导通模式工作,从而降低损耗并减小尺寸。所有开关均被证明可实现理论上的全负载范围零电压开关操作。此外,提出一种混合脉宽调制加相移调制控制策略来实现电压匹配控制并调节功率流;详细介绍其工作原理、工作特点和参数设计原则;最后,搭建一台1 k W实验室样机来验证理论分析。
