Users of protective relays apply these devices specific to their needs and applications. In order to perform this task, schemes are developed and applied to protective relays in the form of relay logic. These methods ...
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ISBN:
(纸本)9781538661277
Users of protective relays apply these devices specific to their needs and applications. In order to perform this task, schemes are developed and applied to protective relays in the form of relay logic. These methods vary depending on the age of the relay as well as the manufacturer's standard of programming. This paper is developed as a tutorial to examine the methods used to develop relay logic schemes. It will look at past methods of discrete contact/switch logic as well as the methods used today such as Boolean and IEC 61131-3 mapping. Logical mapping methods and simplification are considered. A comparison of the various programming methods will ultimately educate the reader as to the tools available to perform the development task. Relay-to-relay logical bit transfer is a method by which automated and protection specific schemes are developed. An examination of these methods is performed as well. Testing relay logic is an additional subject that is examined. Critical to performance of any relay logic scheme are the comprehensive testing methods used to prove the functionality performs according to design intentions. The goal of the paper is to provide a user of any type of relay, electromechanical, solid state or microprocessor, the knowledge of how to properly develop logic schemes and the proper testing methods associated with these schemes.
This paper presents a UML-based engineering environment for the design and implementation of hybrid systems in forming technology. The discrete superordinate steps of forming technology are programmed as an activity d...
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ISBN:
(纸本)9781457700187
This paper presents a UML-based engineering environment for the design and implementation of hybrid systems in forming technology. The discrete superordinate steps of forming technology are programmed as an activity diagram (UML). Some process steps include control loops which are modeled in Simulink. The control loops are automatically generated into continuous function chart (CFC) in Programmable Logic Controller (PLC). The paper describes how the controllers can be distributed with different task cycle times and how the performance of these controllers can be ensured during runtime. In the process, the activity diagram is compared with the standard IEC 61499 considering the aspects usability and execution/implementation.
The changes in the market demand and the envirommental pressures generate the need for adaptation of the manufacturing systems to an ever-increasing rhythm. The greater variety of products, the possible large fluctuat...
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ISBN:
(纸本)9781424425761
The changes in the market demand and the envirommental pressures generate the need for adaptation of the manufacturing systems to an ever-increasing rhythm. The greater variety of products, the possible large fluctuations in demand, the shorter lifecycle of the products expressed by a higher dynamics of introduction of new products, and the increased customer expectations in terms of quality and delivery time are the challenges that manufacturing companies have to deal with, in order to remain competitive and survive in the market. All modern automated manufacturing systems need a material-handling system capable of moving the materials efficiently throughout the entire production process. The holonic concept has two important properties which make this a suitable modelling tool for use in the design of both manufacturing and material-handling systems. First, autonomy grants holons the right to make decisions without consulting any supervising entity. Second, cooperation permits holons to communicate with other peer holons to develop mutually acceptable plans and execute them. In this respect, the article presents a technique for controlling the resources (material handling holons) in a holonic manufacturing platform with multiple robots.
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