发电机定子接地微机保护装置的研制及试验

本文介绍了自调整式的发电机定子接地微机保护装置的研制及其动摸试验结果，着重介绍了保护装置的硬件结构和软件结构及其主要功能，以及保护装置的可靠性和抗干扰性能，从动模实验上证明了自调整式的发电机定子接地微机保护装置的优良性能，为保护装置的推广应用提供了条件。     

A compact and practical CAD system for blanking or piercing of irregular-shaped sheet metal products and stator and rotor parts

This paper describes the development of a computer-aided design of blanking and piercing for irregular-shaped sheet metal products and stator and rotor parts. An approach to the compact and practical CAD system is based on the knowledge-based rules. Knowledge for the CAD system is formulated from plasticity theories, experimental results and the empirical knowledge of field experts. The system has been written in AutoLISP on the AutoCAD with a personal computer and is composed of six main modules, which are input and shape treatment, production feasibility check, blank layout, strip layout, die layout, and drawing edit module. Based on knowledge-based rules, the system, STRTDES, is designed by considering several factors, such as complexities of blank geometry and punch profile, availability of press equipment and standard parts, utilization ratio which minimizes the scrap in a single or a pairwise operation, bridge width, grain orientation and design requirements which maximize the strength of the part when subsequent bending is involved. Therefore, this system can carry out a die design for each process which is obtained from the results of an automated blank layout drawing with the best utilization ratio for the irregular shape of the product, which was successful in the production feasibility check module, and those of an automated strip layout drawing. It can then generate part drawings and the assembly drawing of the die set in graphic form. The developed system provides its efficiency and effectiveness for blank layout, strip layout, and die layout of irregular-shaped sheet metal products and stator and rotor parts.     

Generating multi-section silicon steel sheet cutting patterns in the manufacturing industry of electric generators

Circular and sectorial blanks are often cut from silicon steel sheet to make stators and rotors of electric generators. This paper presents an algorithm to generate optimal multi-section cutting patterns for the blanks. A cutting pattern includes one or more sections, each of which consists of strips of the same direction and length. Blanks in a strip are of the same size. The algorithm employs dynamic programming to generate cutting patterns, and linear programming to determine the cutting scheme. Cutting stock data from a factory that produces electric generators are analyzed, and the results indicate that the algorithm is efficient in improving material usage.