Dispatcher training simulator
Encyclopedia
A dispatcher training simulator (DTS), also known as an operator training simulator, is a computer-based training system for operators (known as dispatchers) of electrical power grids
. It performs this role by simulating
the behaviour of the electrical network
forming the power system under various operating conditions, and its response to actions by the dispatchers. Student dispatchers may therefore develop their skills from exposure not only to routine operations but also to adverse operational situations without compromising the security of supply on a real transmission system.
s linked by scaled-down representations of the interconnecting lines. The operator would simulate the operation of circuit breakers by physically operating their miniature replicas. As transmission systems grew in size and complexity, they could no longer be adequately represented in this manner, and computerised simulations came to the fore.
A modern DTS combines or simulates the following elements:
) at the same time and from the same manufacturer as an energy management system
, and is usually designed to mimic it as closely as possible. Operational scenarios are created on the DTS to represent the operator's transmission system under a variety of conditions. These may represent normal operating conditions, or be specially designed to test the student's responses to adverse circumstances, such as frequent line trips during severe weather. The DTS is administered by a team of instructors, who select scenarios and simulate operational events, monitoring the trainee's actions in response.
Scenarios may also represent circumstances that the system operator hopes never occur, such as complete system shut-down, and allow it to develop strategies for restoration of service (known as black start
).
Deficiencies in operator training were identified as a contributory cause of the 2003 North American blackout, a factor similarly connected to earlier power failures. The joint US-Canadian task force investigating the incident recommended mandatory periods of simulation time for operators, and validation of the models against actual system characteristics.
To enable the training simulator to respond as realistically as possible to the student's actions, the power flow study at its heart must run on a frequent time basis, such as every few seconds. The simulation may model electrical networks consisting of many thousands of nodes and containing several hundred generating units.
Electric power transmission
Electric-power transmission is the bulk transfer of electrical energy, from generating power plants to Electrical substations located near demand centers...
. It performs this role by simulating
Simulation
Simulation is the imitation of some real thing available, state of affairs, or process. The act of simulating something generally entails representing certain key characteristics or behaviours of a selected physical or abstract system....
the behaviour of the electrical network
Electrical network
An electrical network is an interconnection of electrical elements such as resistors, inductors, capacitors, transmission lines, voltage sources, current sources and switches. An electrical circuit is a special type of network, one that has a closed loop giving a return path for the current...
forming the power system under various operating conditions, and its response to actions by the dispatchers. Student dispatchers may therefore develop their skills from exposure not only to routine operations but also to adverse operational situations without compromising the security of supply on a real transmission system.
Description
Early simulations modelled the transmission system with banks of analog computerAnalog computer
An analog computer is a form of computer that uses the continuously-changeable aspects of physical phenomena such as electrical, mechanical, or hydraulic quantities to model the problem being solved...
s linked by scaled-down representations of the interconnecting lines. The operator would simulate the operation of circuit breakers by physically operating their miniature replicas. As transmission systems grew in size and complexity, they could no longer be adequately represented in this manner, and computerised simulations came to the fore.
A modern DTS combines or simulates the following elements:
- An energy management systemEnergy management systemAn energy management system is a system of computer-aided tools used by operators of electric utility grids to monitor, control, and optimize the performance of the generation and/or transmission system...
(EMS): a computer system for controlling a power grid. The EMS enables remote operation of electrical equipment, such as circuit breakerCircuit breakerA circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow...
s or transformerTransformerA transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
s. It also receives information transmitted back to an electricity control centre, such as the status of equipment or notification of alarms. The user interfaceUser interfaceThe user interface, in the industrial design field of human–machine interaction, is the space where interaction between humans and machines occurs. The goal of interaction between a human and a machine at the user interface is effective operation and control of the machine, and feedback from the...
typically displays the state of the transmission system on computerised one-line diagramOne-line diagramIn power engineering, a one-line diagram or single-line diagram is a simplified notation for representing a three-phase power system. The one-line diagram has its largest application in power flow studies. Electrical elements such as circuit breakers, transformers, capacitors, bus bars, and...
s with controllable points for simulated operation of plant such as circuit breakerCircuit breakerA circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow...
s or transformer tap-changersTap (transformer)A transformer tap is a connection point along a transformer winding that allows a certain number of turns to be selected. This means, a transformer with a variable turns ratio is produced, enabling voltage regulation of the output...
. - A SCADASCADASCADA generally refers to industrial control systems : computer systems that monitor and control industrial, infrastructure, or facility-based processes, as described below:...
(Supervisory control and data acquisition) system, which provides collection and assimilation of data from substationsElectrical substationA substation is a part of an electrical generation, transmission, and distribution system. Substations transform voltage from high to low, or the reverse, or perform any of several other important functions...
and transmits operator instructions back to the same plant. - A load-flow studyPower flow studyIn power engineering, the power flow study is an important tool involving numerical analysis applied to a power system. A power flow study usually uses simplified notation such as a one-line diagram and per-unit system, and focuses on various forms of AC power...
to calculate power flows and voltages on the transmission system and to model its responses to disturbances such as line trips, relayRelayA relay is an electrically operated switch. Many relays use an electromagnet to operate a switching mechanism mechanically, but other operating principles are also used. Relays are used where it is necessary to control a circuit by a low-power signal , or where several circuits must be controlled...
action, and generatorElectrical generatorIn electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
-demand mismatch. The model will normally extend to the limits of the system operator's region of interest, and include representations of plant such as linesTransmission lineIn communications and electronic engineering, a transmission line is a specialized cable designed to carry alternating current of radio frequency, that is, currents with a frequency high enough that its wave nature must be taken into account...
, generatorsElectrical generatorIn electricity generation, an electric generator is a device that converts mechanical energy to electrical energy. A generator forces electric charge to flow through an external electrical circuit. It is analogous to a water pump, which causes water to flow...
, transformerTransformerA transformer is a device that transfers electrical energy from one circuit to another through inductively coupled conductors—the transformer's coils. A varying current in the first or primary winding creates a varying magnetic flux in the transformer's core and thus a varying magnetic field...
s, circuit breakerCircuit breakerA circuit breaker is an automatically operated electrical switch designed to protect an electrical circuit from damage caused by overload or short circuit. Its basic function is to detect a fault condition and, by interrupting continuity, to immediately discontinue electrical flow...
s and capacitorCapacitorA capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...
s. - The system may additionally provide facilities for modelling and optimising the economic dispatchEconomic dispatchEconomic dispatch is the short-term determination of the optimal output of a number of electricity generation facilities, to meet the system load, at the lowest possible cost, while serving power to the public in a robust and reliable manner...
of generating units. Any generation's dynamic characteristics and limits, in particular its voltage regulationVoltage regulationIn electrical engineering, particularly power engineering, voltage regulation is the ability of a system to provide near constant voltage over a wide range of load conditions.-Electrical power systems:...
, maximum generation, and rate of change of outputSlew rateIn electronics, the slew rate represents the maximum rate of change of a signal at any point in a circuit.Limitations in slew rate capability can give rise to non linear effects in electronic amplifiers...
are usually incorporated.
Operation
A DTS is frequently purchased by a customer (such as a transmission system operatorTransmission system operator
File:Electricity grid simple- North America.svg|thumb|380px|right|Simplified diagram of AC electricity distribution from generation stations to consumersrect 2 243 235 438 Power stationrect 276 317 412 556 Transformer...
) at the same time and from the same manufacturer as an energy management system
Energy management system
An energy management system is a system of computer-aided tools used by operators of electric utility grids to monitor, control, and optimize the performance of the generation and/or transmission system...
, and is usually designed to mimic it as closely as possible. Operational scenarios are created on the DTS to represent the operator's transmission system under a variety of conditions. These may represent normal operating conditions, or be specially designed to test the student's responses to adverse circumstances, such as frequent line trips during severe weather. The DTS is administered by a team of instructors, who select scenarios and simulate operational events, monitoring the trainee's actions in response.
Scenarios may also represent circumstances that the system operator hopes never occur, such as complete system shut-down, and allow it to develop strategies for restoration of service (known as black start
Black start
A black start is the process of restoring a power station to operation without relying on the external electric power transmission network.Normally, the electric power used within the plant is provided from the station's own generators...
).
Deficiencies in operator training were identified as a contributory cause of the 2003 North American blackout, a factor similarly connected to earlier power failures. The joint US-Canadian task force investigating the incident recommended mandatory periods of simulation time for operators, and validation of the models against actual system characteristics.
To enable the training simulator to respond as realistically as possible to the student's actions, the power flow study at its heart must run on a frequent time basis, such as every few seconds. The simulation may model electrical networks consisting of many thousands of nodes and containing several hundred generating units.