Power System Modelling , Analysis and Control

Overview  Economic Distribution of Loads between the Units of a Plant  Generating Limits  Economic Sharing of Loads between Different Plants A good business practice is the one in which the production cost is minimized without sacrificing the quality. This is not any different in the power sector as well. The main aim here is to reduce the production cost while maintaining the voltage magnitudes at each bus. In this chapter we shall discuss the economic operation strategy along with the turbine-governor control that are required to maintain the power dispatch economically. A power plant has to cater to load conditions all throughout the day, come summer or winter. It is therefore illogical to assume that the same level of power must be generated at all time. The power generation must vary according to the load pattern, which may in turn vary with season. Therefore the economic operation must take into account the load condition at all times. Moreover once the economic generation condition has been calculated, the turbine-governor must be controlled in such a way that this generation condition is maintained. In this chapter we shall discuss these two aspects.

2017

A system which checks the quality of automatic control system and diagnoses power unit’s operation is presented. The system is cooperates with existing DCS systems. Using the received, registered and processed data, the analysis results are presented. They allow the performance evaluation of the control systems and power unit (technological parameters excess and its influence on efficiency, characteristics of executive elements and directive to its linearization, valves tightness, valves and pumps cavitation, start-up costs) in a given period. The received information enables the operators to take preventive action in advance. Consequently, it is possible to obtain more efficient power station’s operation and the exploitation cost reduction.

ISA Transactions, 2000

This paper discusses an electrical control and energy management system (ECEMS) that was installed at Indian Petrochemicals Corporation Limited (IPCL) Nagathone Gas Cracker complex located in Maharashtra, India. This distributed control system (DCS) provided computer assisted control in the areas of: Demand control; Automatic generation control, including MW and MVAR management; Power factor control; Automatic tap changer control; Load shedding; Automatic synchronization of generator and ties; Remote control of breakers. Previously, IPCL, like most other petrochemical companies in India, relied on operator control for power house functions. The process is always automated, but the power house equipment is usually manually controlled. Electrical control and energy management systems are not thought to be necessary. However, in this case the consultants for IPCL and the DCS supplier convinced IPCL that an ECEMS would save them enough money in operating costs to pay for the new control system. The control system discussed in this paper reduced operating costs by satisfying the process steam and power demands in the most cost-eective manner. In addition, the system took action to respond to electrical disturbances, such as loss of tie line and generator tripping, so that stable conditions were restored. #

Welcome to power system operation and control course in which the lecture module one consist of structure evolution, and also we will see the main requirements for the power system operation and control. Before going as you know, this electricity is one of the important essentials for any development of any country and also for the mankind. The commercial use of electricity is started in the late 1870s; however, the invention of the electricity took place very beginning.

2005

BAS Building automation systems, also known as EMCS. BMS Building management systems, also known as EMCS. Cascading Resets An example of cascading resets is when both the chilled-water supply temperature as well as the supply air temperature are reset in a sequence. Commissioning A process to ensure that EMCS is designed, installed, functionally tested, and capable of being operated and maintained according to the owner's operational needs. Controller Processes data that is input usually from a sensor, performs logical operations based on the device being controlled and causes an output action to be generated. Economizer Air-side economizers use controllable dampers to increase the amount of outside-air intake into the building when the outside air is cooler than the return air and the building requires cooling. Demand Limiting A control function that enables management of peak demand level by shedding predefined loads when the building/facility demand nears a preset maximum. DDC Direct digital controls, also known as EMCS. DDE Direct data exchange is a standard Microsoft Windows® message-passing protocol that defines a mechanism for Windows applications to share information with one another. vi Distributed Facility Management of building and facilities that are distributed over a wide Management geographical region. Although each building has its own EMCS systems, the buildings are also managed remotely from a central location through use of gateways and software applications. EMCS Energy management control systems FMS Facility management systems, also known as EMCS. Gateways Devices that allow for integration of control networks with internet, so that the devices/controllers on the control network can be accessed through the internet Interoperability Ability of a device/controller or a product to work with other devices/ controllers or products without special effort on the part of the customer. Latent Cooling Moisture removal through dehumidification LonTalk A communication protocol for LonWorks devices to communicate with each other on a LonWorks network. LonWorks A networking platform created by Echelon Corporation. MODBUS A standard communication protocol developed by the Modicon Corporation. The MODBUS protocol is often used in facility metering applications. OLE Object linking and embedding is like DDE, a standard Microsoft Windows® message-passing protocol, which defines a mechanism for Windows applications to share information with one another. Ratchet Clause A term in a customer's contract or rate schedule (tariff) that dictates that the customer's billings for each billing period must be based at least in part on the maximum billing received by that customer over a given period, usually the preceding year. Sampling Interval The interval between two consecutive adjustments of control parameters. Settling Interval Time required for the control to settle after a change in a control parameter. Temperature Reset Adjustment of supply temperature higher (during cooling) or lower (during heating) to match the heating and cooling needs.

The task of protection and control in substations and in power grids is the provision of all the technical means and facilities necessary for the optimal supervision, protection, control and management of all system components and equipment in high and medium-voltage power systems. The task of the control system begins with the position indication of the HV circuit-breaker and ends in complex systems for substation automation, network and load management as well as for failure-and time based maintenance. For all these functions the data acquisition at the switch yard and – if applicable-the command execution at the switch yard are part of the network control and management. Fig. 14-1 provides an overview of the functions and subsystems that make up the control technology in the context of electric power transmission and distribution. The purpose of these secondary systems is to acquire information directly at the high-and medium-voltage apparatus in the substations and to allow their safe on-site operation, including the secure power supply of all their parts. Modern automation technology provides all the means necessary for processing and compressing information at the actual switchgear locations in order to simplify and secure normal routine operation. This allows more efficient use of existing equipment and quick localization and disconnection of faults in case of troubles, thereby also reducing the load on the communication links and in the network control centers. Protection devices are required to safeguard the expensive power equipment and transmission lines against overloads and damages. Therefore, they have to switch off very quickly short circuits and earth faults and to isolate very selectively the faulted or endangered parts in the power system. They are thus a major factor in ensuring the stability of the power system. The purpose of power system control as a subdivision of power system management is to secure the transmission and distribution of power in the more and more complex power systems by providing each control centre with a continually updated and user-friendly overall picture of the entire network. All important information is transmitted via communication links from the substations to the control centre, where it is instantly evaluated and corrective actions are taken. The growing amount of data acquired, the increasing communication bandwidth and the performance and memory capacity of modern computers have resulted in replacement of conventional mosaic panels for direct process control by computer based control systems with screen or video based displays. In few cases, conventional mimic panels are still kept for power grid overview.

Systems Analysis Modelling Simulation, 2003

Proceedings of the ... Annual Hawaii International Conference on System Sciences, 2017

Recent technological advances in protection, control and optimization are enabling a more automated power system. This paper proposes the use of these technologies towards an integrated and seamless infrastructure for protection, control and operation. This infrastructure is the basis for accommodating and providing robust solutions to new problems arising from the integration of renewables, namely more uncertainty and steeper ramp rates. At the lower level we propose a dynamic state estimation of a protection zone (EBP) for the purpose of providing protection for the zone. The estimation based protection (EBP) provides the real time dynamic model of the zone as well as the real time operating conditions. Since protection is ubiquitous, it can cover the full system. We assume that GPS synchronization of the EBP is available providing accurate time tags for the real time model and operating conditions. The real time model and operating conditions can extent from the "turbine to the toaster". We propose a methodology for automatically constructing the power system state locally and centrally at the control center with distributed controls as well as centralized controls depending on the application. For example, the centralized system wide real time model is used to perform system optimization functions, and then send commands back through the same communication structure to specific power system components. Since protection is ubiquitous and the modern power system has several layers of communication infrastructure, the proposed approach is realizable with very small investment. The availability of the real time dynamic model and state locally and centrally enables the seamless integration of applications. Three applications are discussed in the paper: (a) settingless protection, (b) voltage/var control and (c) feeder load flexibility scheduling. The proposed approach and infrastructure can form the basis for the next generation of Energy Management Systems.