**6. Conclusion**

Training programmes for power plant operators using dynamic simulator have been used extensively in many parts of the world during the last 30 years, and their direct benefits in unit availability, thermal performance, environmental compliance and safe operation have

One of the most viable approaches to simulate the DCS is the translation of the control algorithms of the actual power plant; this guarantees a full reproduction of all control loops, alarms and signals to the HMI. In the context of a simulator and according to the methodology described by Romero-Jiménez et al. (2008), the translation procedure involves

Building the libraries of analogue and logic components (e.g. PID controllers, logical

Designing interfaces with a description outside software implementation, so the code

 Implementation of an on-line visor to verify and visualize signals, states, inputs, outputs and parameters of components during simulation. This visor allows disabling diagrams, modules or components, in this way, it is possible isolate components and

In the case of small control systems or when the control loops are not included in the DCS for its translation, these control algorithms can be developed by means of a graphical tool like VisSim (VisSim, 2011), using as reference the SAMA diagrams of the actual power plant. VisSim provides almost all the basic modules required to model control systems and generates C code, so it can be easily coupled to the simulator solver. In such way, the SAMA diagrams can be drawn totally in the VisSim environment to reproduce the required control. As expected, it is necessary coding in a manual way the modules with a specific function do

Training programmes for power plant operators using dynamic simulator have been used extensively in many parts of the world during the last 30 years, and their direct benefits in unit availability, thermal performance, environmental compliance and safe operation have

requiring an interface can use any component/object (Polymorphism).

Design and implementation of a control component database.

Fig. 14. Control diagram of a DCS

mainly the next tasks:

gates, timers, etc.)

verifying their behaviour.

not available in the VisSim libraries.

**6. Conclusion** 

 Organizing the component execution sequence. Creating structures in order to store component states. been proven and documented. It is important to mention that, simulators are a very important part of these programmes, but their value as training tool is maximized when they are integrated in well-designed and structured training courses. The ADDIE model is a suitable methodology to get this goal.

The increase of power computing and the development of friendly graphical user interfaces had two main effects over the simulators; on the one hand, the power plants have replaced their former control boards with personal computers with graphical user interfaces. Naturally, the operators of these plants need a suitable training because they face a complete change in their operation paradigm, and because of this, the training simulators also require a HMI as the ones in the actual plants. On the other hand, a complete simulator can be installed in a single PC, with no demerit of the scope of the mathematical modelling or its real-time functioning. Furthermore, web services and cloud computing extend the training options, because specific training objectives can be fulfilled just with a PC with an internet connection. This kind of applications make possible to reach a big number of trainees with no necessity of: transporting personnel to a training centre, transporting a simulator to different places, or acquiring a simulator. Another important aspect is the inclusion of expert systems in a training simulator. This option is suitable for standalone applications which require reducing or even eliminating the necessity of a human instructor. A convenient knowledge representation of the expert gives to the simulation system all the elements to conduct a training session in an autonomous way.

In the Object-Oriented Programming, an object is the mathematical model of a power plant component and the integration of these objects reflects the physical plant layout. The interactions among the components are satisfied with connectors, which are also related with the actual physical connections; this type of approaches simplifies the construction of simulators and provides a direct relation between the physical and simulated systems.
