A dispatcher training simulator (DTS), also known as an operator training simulator (OTS), 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.[1] 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.
Early simulations modelled the transmission system with banks of analog computers 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:
A DTS is frequently purchased by a customer (such as a transmission system operator) 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.