Control Of Power Distribution Systems Research Articles

Impact of Fuel Cells on Load-Frequency Control in Power Distribution Systems

This paper describes a concept of a distribution system that has enough generation to track its load without the help of a substation. Specifically, it addresses the presence of solid-oxide fuel cells in the distributed generation mix. Two control loops are proposed: 1) to guarantee that the fuel cell is protected by maintaining its cell utilization within its admissible range and 2) to track load changes and regulate the frequency. The two respective loops are called primary and secondary loops. The primary loop maintains constant the ratio of stack current to input fuel flow, and the secondary loop tracks the load and regulates the frequency. A distribution area error (DSE) is introduced to formulate the frequency-control problem. The secondary loop feeds back this DSE signal. Tuning of the parameters is performed using genetic algorithms.

Fuzzy inference system to assist the operator in reactive power control in distribution systems

The paper proposes a fuzzy inference system to assist the operator for voltage control and power loss minimisation. The reactive power control problem is decoupled from the voltage regulator problem. A fuzzy expert system provides rules for both the problems. The fuzzy inference system acts as the front-end to determine the control variables for the two decoupled problems. An existing 30-bus distribution system is used to demonstrate the effectiveness of the above approach. Simplicity of approach and speed make it a viable option for online Var control.

Knowledge-based expert system for optimal reactive power control in distribution system

Knowledge-based expert system for optimal reactive power control in distribution system

Knowledge-based expert system for optimal reactive power control in distribution system

In this paper a knowledge-based expert system for the general capacitor placement problem is formulated by taking into account the practical aspects of capacitors, load constraints and operational constraints at different load levels. The developed expert system uses the simulated annealing (SA) technique for global optimal solution for reactive power compensation. The SA technique is made suitable for an expert system by providing the initial estimate and placement of reactive sources using the set voltage magnitude method (SVM). A set of rules is developed which is capable c f modifying the step size of the control variable when ever the toggling of the control direction is detected. General rules are developed for optimal reactive power control. The developed expert system is tested for a practical 85-bus radial distribution system of Mysore City, South India. The results obtained are encouraging and acceptable in practice.

174 An integrated environment for operational planning and control in power distribution systems: C.N. MacQueen, M.R. Irving, M.J.H. Sterling, pp 837– 840

174 An integrated environment for operational planning and control in power distribution systems: C.N. MacQueen, M.R. Irving, M.J.H. Sterling, pp 837– 840

An Integrated Environment for Operational Planning and Control in Power Distribution Systems

An integrated simulation and analysis environment is presented which assists distribution system operations engineers in increasing system utilisation and efficiency. A load-flow based discrete time simulator interfaces with a relational plant database, load modelling software and data from SCADA systems to track the behaviour of the system with time. Further analysis can be conducted at any time to study fault levels, transient behaviour and the effects of contingencies. Recent developments in X Windows graphics and relational database technology are employed to manage the data efficiently.

Solid-state power controller for the next generation

The design philosophies of an electrical load management center (ELMC) for military platforms and the advantages and features made possible only through the use of real-time solid-state power controllers (SSPCs) are discussed. Computer control of power distribution systems will be required to off-load crews and increase system reliability, with improved fault handling, while also protecting the wire and load. The electrical, mechanical, and special competitive features of the SSPC series, the military screening and mechanical specifications, and other product options are highlighted.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

On-line expert system for power distribution system control

The application of expert systems in power systems has attracted much attention both academically and industrially. This paper reports on the development, testing, and commissioning of an expert system for the on-line control of a distribution network. The expert system is used to determine the optimal switching operation sequence for load rerouting during fault restoration, emergency operation overload relieving, and network maintenance planning. The main features of the system can be summarized as follows. Employment of hierarchical structure of knowledge base decision tree, introduction of function-oriented and network scale-oriented rules, easily changable priorities used during decision making can be done using a CRT display, in addition to the facility of changing the network operating constraints. The results of such changes can be evaluated by a built-in simulator using a snapshot of the on-line data. A tracing facility is also introduced to trace the reasoning during the decision making process. The techniques used, development process, system evaluation and testing are reported.

Automatic Power Distribution Reconfiguration Algorithm Including Operating Constraints

A generalized reconfiguration algorithm applied to automated remote control of power distribution systems is described. The algorithm combines two independent processes: a Service Restoration to dark zones and a Load Balance between feeders. Electrical opera ting cons traints are included in the analysis using an appropriate fast decoupled load flow. Simulation results obtained with a real distribution system data base are presented showing the influence of operating restrictions. The way of interchange the restoration and balance processes is also discussed.

Hierarchical control of power distribution systems

The concepts of hierarchical system theory, in conjunction with power system engineering, have been applied to enable the real-time control of a large-scale power distribution system.1 The control objective of the distribution system consists of security (equipments protection) and operation (continuity of service) requirements to be satisfied within the feasible control boundaries for all substations composing the distribution system. The overall control strategy for each substation is decomposed into independent control functions which are ordered (ranked) to meet a hierarchy of control requirements specified by the system's physical operation. This approach was adopted not only to simplify the real-time control problem solution, but also was necessitated by the requirement that a partial feasible solution be provided which meets higher priority objectives when a total feasible solution does not exist. This paper describes, in the hierarchical framework, the physical process, the network decomposition and modeling, the control decomposition and criteria, and the control procedure along with numerical results.

Carrier current control of power distribution system

Carrier current control of power distribution system