Current-transfer phase-control breaking is one method of paralleled breaking. This method can make up for shortcoming of sole chamber with high rated current and high rated short-current breaking current at the same t...
详细信息
Current-transfer phase-control breaking is one method of paralleled breaking. This method can make up for shortcoming of sole chamber with high rated current and high rated short-current breaking current at the same time. In addition to breaker stationary open time and computing speed of controller, the key influence factor is that controller needs accurately to compute the current-transfer time and current zero appearing moment. It will influence the best triggering moment determination of breaker driving actuator. This paper constructs its mathematical model of current transfer process. By the theory modeling with Matlab, this paper analyzes the influencing factors to current-transfer time and current zero appearing moment. From simulation procedure and result, dc component of short-circuit current and short-circuit current phase angle of contact separating moment of first open chamber, impedance parameter of paralleled circuit and arc voltage of first open chamber after contact separating both influence the current process and current zero. After breaker structure and chamber parameters are fixed, most important matter is that short-circuit current phase angle of contact separating moment of first open chamber needs to be determined accurately.
This paper verified effect and feasibility by indoor model test of using drainage of vacuum preloading method and electro-osmosis method to reduce water content of saturated over-wet soil in moist and rainy areas. The...
详细信息
General topology has been introduced into the realm of rough sets. In this paper, the topological properties of map on generalized rough approximation space on binary relation are discussed. We point out that a map be...
详细信息
General topology has been introduced into the realm of rough sets. In this paper, the topological properties of map on generalized rough approximation space on binary relation are discussed. We point out that a map between a generalized rough approximation space and a finite set can induce a binary relation on the finite set. If the binary relation is reflective and transitive, then the map is continuous which is regarded as a map on topological space. Furthermore, if the map is bijective, then it is simultaneously open and closed, and image and inverse image of a rough set are rough.
暂无评论