MODELING CONTROLLERS AND GENERATORS
In studies of planning and expansion of power systems, suitable models of controllers (voltage regulators and speed regulators) and generating units (turbines and generators) are needed.
Such models provided by manufacturers require validation field tests, confirming that the model represents the physical system properly.
Standardized models of controllers can be used in studies and parameters validated through field trials. However, it is possible to pick up the driver transfer function that does not fit the standard models.
After the field tests, the obtained curves are compared with the simulated ones.
And a survey of appropriate studies in mathematical models of power systems, field tests bring other benefits:
- Actual operating limits of the generator;
- Knowledge including restrictions imposed by the excitation, turbine system, etc .;
- Inadequate adjustment detection of excitation limiters and PSS system;
- Coordination problems between the control system and the protective devices;
- Inadequate operation of the unit (for example, the unit makes primary regulation, dead band frequency, voltage control for power factor, limiting restrictions, etc.).
Simulation models can be run to evaluate the individual plant performance as well as the performance of the complete interconnected system. Through these studies, it is possible to analyze:
- Coordination of the protection of the generator with the limitation of the excitation system;
- Operational limits of the synchronous generator;
- Adjustment Voltage Regulator (AVR) and Dynamic Limiters;
- Adjusting the power system stabilizer;
- Adjust the compensator’s reactive voltage regulator;
- Analysis of unit control mode.