1、PDF外文：http:/ Planning of Substation Automation System Cables Thanikesavan Sivanthi and Jan Poland ABB Switzerland Ltd, Corporate Research, Segelhofstrasse 1K, 5405, Baden-Dattwil, Aargau, Switzerland Abstract The manual selection and assignment of appropriate cables to the interconnectio
2、ns between the devices of a substation automation system is a major cost factor in substation automation system design. This paper discusses about the modeling of the substation automation system cable planning as an integer linear optimization problem to generate an efficient cable plan for substat
3、ion automation systems. 1 Introduction Cabling between different devices of a substation automation system (SAS) is a major cost factor in the SAS design process. Usually computer aided design software is used to create the design templates of SAS devices and their interconnections. The design
4、 templates are then instantiated in a SAS project and the cables are manually assigned to the connections. The selection and assignment of cables to connections must follow certain engineering rules. This engineering process is usually time consuming and can cause engineering errors, thereby increas
5、ing the engineering cost. Apparently, the SAS cable planning is related to the well known bin packing problem. The SAS cable planning can be formulated as an integer linear optimization problem with the cable engineering rules expressed as a set of linear constraints and a cost objective for minimiz
6、ing the total cable cost. This paper describes the formulation of SAS cable planning problem as an integer linear optimization problem and presents the results for some representative test cases. To the best of the authors knowledge the work is the first of the kind to study SAS cable planning. The
7、paper is organized as follows. Section 2 presents an overview of the SAS cable planning process. Section 3 expresses the SAS cable planning problem as an integer linear optimization problem. The results obtained by solving the optimization problem using some solvers is presented in Section 4. Sectio
8、n 5 draws some conclusions of this work. 2 SAS Cable Planning The SAS cable planning begins after the system design phase of a SAS project. The SAS cable planning is at present done manually by computer aided design T. Achterberg and J.C. Beck (Eds.): CPAIOR 2011, LNCS 6697, pp. 210214, 2011.c
9、 Springer-Verlag Berlin Heidelberg 2011 Efficient Planning of Substation Automation System Cables 211 Fig. 1. Fields, devices and their interconnections (CAD) engineers. The different design templates corresponding to the actual devices of a SAS are instantiated in one or more CAD jobs.
10、Each job consists of one or more sheets and each sheet has fields which are logical groups of devices as shown in Figure 1. Moreover, a field corresponds to a physical assembly interface class e.g. Metering box, Protection cubicle etc. Each device has pins which are the physical interconnection inte
11、rfaces of the device. A valid connection is a unique path between exactly two pins and every connection carries a physical signal. A signal can traverse over one or more connections. Each connection is assigned to exactly one of the conductors of a cable. The type of cables to which the connections
12、are assigned is based on cable engineering rules. The cable engineering rules can be classified into two types, namely the cable rules and the signal rules. The cable rules specify the allowed cable types for a set of connections. It can also specify the number of spare conductors which must be left
13、 free in each instance of the allowed cable types. The signal rules specify restrictions on allocation of connections which carry signals that should not be allocated to the same cable or preferably allocated to the same cable. The current practice is to manually select and assign cables to connecti
14、ons according to the cable engineering rules. This procedure is time consuming and can cause engineering errors thereby increasing the engineering cost. In what follows is the formulation of the SAS system cable planning as an integer linear optimization problem with which a more efficient cable pla
15、n for SAS can be generated. 3 Integer Linear Program Formulation The SAS cable planning problem is divided into sub problems where each sub problem considers connections between distinct set of field pairs within a given set of CAD jobs. The rationale behind this decomposition is that the cabl
16、e plan should consider the physical assembly interface classes and should not mix connections between two different source or destination physical assembly interface classes in one cable. This is ensured by deriving a cable plan for each distinct field pairs. Let C = 1, 2, 3, . . .,N represent the set of all connections between two field pairs, where N is the
