Distributed Automation Control Research Articles

Ontology Driven Approach to Generate Distributed Automation Control From Substation Automation Design

This paper proposes a method for the automatic generation of smart-grid automation systems software from specifications that includes physical system layout and domain-specific functional “recipes.” The generated software has component organization and implements a decentralized approach to smart grid control, which reduces complexity of automation systems design and modification. The proposed method relies on synergies of two industrial standards IEC 61850 and IEC 61499, which are used to represent a part of the specification and the resulting software model, respectively. Then, the specification model is created in a form of ontology and the generation is based on ontology transformation. The proposed method requires an extension to the Semantic Web Rule Language (SWRL) to support the change of an ontology axioms set for the purpose of ontology transformation. The proposed transformation language, called extended SWRL, is introduced and illustrated in use. The result shows the viability of eSWRL as an ontology transformation language when demonstrated in a power distribution case study system.

The Building of Distributed Automation Control Systems based on PLC Programming and Extends IEC 61131 Standard

The Building of Distributed Automation Control Systems based on PLC Programming and Extends IEC 61131 Standard

Multistage capacitor switching: an analytical approach

Presented in this paper is a novel mathematical formulation for the multistage capacitor scheduling problem in a radial distribution feeder using a predetermined reactive load duration curve. The objective is to determine the optimal switching times of the predetermined capacitor stages to minimize the energy losses under varying load conditions. The presented methodologies are superior to previous works in generalizing the solution to avoid constraints on the number of capacitors and their switching stages. Three different models for the reactive load duration curve are considered. A closed-form solution for the switching time and energy loss reduction is derived from each case. The presented methodologies are simple and efficient. They provide several capacitor control alternatives of value in distribution automation control. The new methodologies are applied to representative radial systems for validation.

Low Cost Hierarchical Control of an Assembly Flow Line

Much work has been carried out within the last few years to link together "islands of automation" on a factory floor using local area networks. This has led to the development of standards in communication systems, such as the Manufacturing Automation Protocol sponsored by the General Motors Corporation. At present a standard, low-cost approach to implementing manufacturing systems, ensuring compatability with the higher-cost MAP-based systems, is not available. If such a standard were available then small firms could install distributed automation control systems incrementally. This paper describes the application of multi-level, hierarchical control to a simple assembly flow line for the consumer electronics industry. There are four basic levels in the system, the lowest being an assembly operation carried out by human or robotic operators. A number of separate assembly operations, each controlled by work station controllers, are formed into a flow line with a number of flow lines forming the complete manufacturing facility controlled by a Computer Aided Manufacture (CAM) host. It is only at the level of the flow line controller and above that the MAP protocols can be applied cost-effectively in a small manufacturing environment. Adoption of the hierarchical approach throughout the system ensures that it is flexible, reliable, easily maintained and can be installed incrementally. The standardisation of low-cost local area networks (LANs) to interconnect the programmable logic controllers (PLCs) is crucial to this task because the lower level communication can then be implemented at much reduced cost as the performance required is minimised. An analysis of the requirements and implementations of LANs for this purpose is provided. To ensure correct operation of the workstation controllers and the associated communication to their flow line controller, a complete and novel Petri-net based logic controller design (PNLC) has been tested. This allows emulation and simulation of algorithms in the stations, to prove both the algorithms and their intercommunication are correct, prior to direct transfer to running on the factory floor.