The mathematical model of an electromechanical system with an asynchronous generator with rotor’s current regulation by frequency converter with an autonomous voltage inverter controlled by current controllers has been described in the article.
Asynchronous generators due to their simplicity are widely used in wind power plants. The rotor currents regulation by frequency converter allows to control the speed and power factor in the stator’s circle. In this case, the power of the frequency converter is determined by the range of slip variation and can be 25–30 % of total power of the generator.
The synthesis of the corresponding control system requires the development of a mathematical model that should take into considertion the nonlinearity of magnetic link in the asynchronous machine and the mutual interactions between components of the system. The combination of a real control system with a real-time mathematical model of the power scheme using the «hardware-in-the-loop» technology allows to test and configure the control system.
The feature of the model is the use of author’s method of an average voltage on integration step for mathematical modeling of electrical circuits. The using of this method allows the high calculation performance and stability, and, also, ensured the continuous operation of the computer model in a real time mode in combination with physical objects (as example with a physical controller). This allows it to be used to synthesize and test control systems of asynchronous generator.
The vector control system implemented in the model provides the regulation of the rotational speed of the generator and the reactive power in the stator’s circle and creates conditions for the use of the specified system, for example, for wind power plants.
W. Qiao, «Dynamic modeling and control of doubly fed induction generators driven by wind turbines,»2009 IEEE/PES Power Systems Conference and Exposition, Seattle, WA, 2009, pp. 1-8.
https://doi.org/10.1109/PSCE.2009.4840245
Pak L-F., Dinavahi V., Real-time simulation of wind energy system based on the doubly-fed induction generator, IEEE Transactions on Power Systems, vol. 24, no. 3 (2009), 1301-1309
https://doi.org/10.1109/TPWRS.2009.2021200
Wang C., Fang X., Yongjie F., Comparative simulation of dynamic characteristic of wind turbine doubly-fed induction generator based on RTDS and Matlab, IEEE International Conference on Power System Technology, (2010), 1-8
Wu F., Zhang X. P., Godfrey K., Ju P., Small signal stability analysis and optimal control of a wind turbine with doubly fed induction generator, IET- Generation, Transmission and Distribution, vol. 1, no. 5 (2007), 751-760
https://doi.org/10.1049/iet-gtd:20060395
T. Lei, M. Barnes and M. Ozakturk, «Doubly-fed induction generator wind turbine modelling for detailed electromagnetic system studies,» in IET Renewable Power Generation, vol. 7, no. 2, pp. 180-189, March 2013.
https://doi.org/10.1049/iet-rpg.2012.0222
R. A. Ufa, A. S. Vasilev and A. A. Suvorov, «Development of hybrid model of B2B HVDC,» 2017 International Conference on Industrial Engineering, Applications and Manufacturing (ICIEAM), St. Petersburg, 2017, pp. 1-5.
https://doi.org/10.1109/ICIEAM.2017.8076224
K. Ou et al., «MMC-HVDC Simulation and Testing Based on Real-Time Digital Simulator and Physical Control System,» in IEEE Journal of Emerging and Selected Topics in Power Electronics, vol. 2, no. 4, pp. 1109-1116, Dec. 2014.
https://doi.org/10.1109/JESTPE.2014.2337512
Plachtyna O. A hybrid model of the electrical power generation system / Plachtyna O., Kutsyk A. // Proceeding of 10th International Conference on Compatibility, Power Electronics and Power Engineering (CPE-POWERENG), IEEE Conference Publications. 2016. PP. 16 - 20.
https://doi.org/10.1109/CPE.2016.7544031
Plachtyna O. G. Chyslowyj odnokrokowyj metod anlizu elektrychnych kil i joho zastosuvannia v zadachah elektromechaniky. [Numerical one-step method for the analysis of electric circuits and its application in the problems of electromechanics] // Visnyk NTU "Harkivskij politehnichnyj instytut". 2008. No. 30. pp. 223-225. (ukr.)
Plachtyna E.G. Matematicheskoje modelirovanie elektromashyno-ventilnyh sistem. [Mathematical modeling of elektromechanical systems with semiconductor converters ]. Lviv: Vyshcha shkola, 1986. 161 p. (rus.)
Plachtyna O. G., Kutsyk A. S., Tutka V. V. Synhronizacija rozrahunkovogo chasu funkcionuvannia matematychnych modelej elektromashynoventylnyh system z realnym chasom. [Synchronization of the calculated time of electromechanical systems mathematical models with a real-time] // Visnyk NU "Lviv Politechnic" "Electric power and electromechanical systems" 2009. No. 637. - P. 67-70.