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
The automatic chain shell magazine is the primary subassembly of the automatic ammunition loading system of a big-caliber howitzer. Due to the change of the shell amount in the magazine during firing, its positioning ...The automatic chain shell magazine is the primary subassembly of the automatic ammunition loading system of a big-caliber howitzer. Due to the change of the shell amount in the magazine during firing, its positioning control is a kind of control problem of systems with uncertain parameters. In order to realize accurate control of shell position, an optimal guaranteed cost control algorithm based on linear matrix inequality (LMI) theory was put forward. The motion equations of the magazine were built, and the motion equations for four special load situations were linearized; according to the basic theory of the guaranteed cost control, the motion equations were written as the standard forms for linear uncertain systems; the optimal guaranteed cost control law for the position control of the magazine was obtained by use of LMI toolbox in MATLAB package. Using this control law, the controlled dynamic simulation of the shell magazine was carried out. The simulation results indicate that the control algorithm has high control precision.展开更多
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The automatic chain shell magazine is the primary subassembly of the automatic ammunition loading system of a big-caliber howitzer. Due to the change of the shell amount in the magazine during firing, its positioning control is a kind of control problem of systems with uncertain parameters. In order to realize accurate control of shell position, an optimal guaranteed cost control algorithm based on linear matrix inequality (LMI) theory was put forward. The motion equations of the magazine were built, and the motion equations for four special load situations were linearized; according to the basic theory of the guaranteed cost control, the motion equations were written as the standard forms for linear uncertain systems; the optimal guaranteed cost control law for the position control of the magazine was obtained by use of LMI toolbox in MATLAB package. Using this control law, the controlled dynamic simulation of the shell magazine was carried out. The simulation results indicate that the control algorithm has high control precision.
