DescriptionĪ 9 MW wind farm consisting of six 1.5 MW wind turbines connected to a 25 kV distribution system exports power to a 120 kV grid through a 30 km, 25 kV feeder.
![dfig and wind farm simulation in neplan dfig and wind farm simulation in neplan](https://docplayer.net/docs-images/43/10020925/images/page_10.jpg)
In the phasor simulation method, the sinusoidal voltages and currents are replaced by phasor quantities (complex numbers) at the system nominal frequency (50 Hz or 60 Hz).This is the same technique which is used in transient stability software. This model is better adapted to simulate the low frequency electromechanical oscillations over long periods of time (tens of seconds to minutes). The phasor model (continuous) such as the one presented in the "power_wind_dfig" model in the Renewable Energy examples library. This model allows using much larger time steps (typically 50 microseconds), thus allowing simulations of several seconds. This model does not represent harmonics, but the dynamics resulting from control system and power system interaction is preserved. In this type of model the IGBT Voltage-sourced converters (VSC) are represented by equivalent voltage sources generating the AC voltage averaged over one cycle of the switching frequency.
![dfig and wind farm simulation in neplan dfig and wind farm simulation in neplan](https://ars.els-cdn.com/content/image/1-s2.0-S0142061516307487-gr1.jpg)
The average model (discrete) such as the one presented in the power_wind_dfig_avg model in the Renewable Energy examples library. This model is well suited for observing harmonics and control system dynamic performance over relatively short periods of times (typically hundreds of milliseconds to one second). In order to achieve an acceptable accuracy with the 1620 Hz and 2700 Hz switching frequencies used in this example, the model must be discretized at a relatively small time step (5 microseconds). The detailed model includes detailed representation of power electronic IGBT converters. The detailed model (discrete) such as the one presented in this example.
![dfig and wind farm simulation in neplan dfig and wind farm simulation in neplan](https://demo.documents.pub/img/378x509/reader018/reader/2020010701/54615524b1af9fba388b471a/r-2.jpg)
Depending on the range of frequencies to be represented, three simulation methods are currently available in Specialized Power Systems to model VSC based energy conversion systems connected on power grids.