D, Q reference frames for the simulation of multiphase (six phase) wound rotor induction generator driven by a wind turbine for disperse generation

Abstract

The wound rotor induction machine has been traditionally accepted for a long time in a wind energy conversion system. Despite numerous concepts have been established on wound rotor induction generator (WRIG), the WRIG is lacking in the area of the multi-phase system. Hence the interest of research fraternity starts growing toward modelling of un-conventional WRIG with Wind Energy Conversion System. In this direction, six-phase wound rotor induction generator (SPWRIG) can be a game changer, because it has the property of WRIG as well as multi-phase technology. This study introduces the novel SPWRIG based on mathematical modelling, control technique, simulation and experimental results. As a major novelty, this study has included a comparison of various currents and its importance in the excitation reference frame, rotor reference frame, stator reference frame. The accuracy of mathematical modelling has been tested by experimental and simulation results. Nomenclature A s , ψ s , ω s , X s , Y s , Z s six terminals of the stator winding A r , ψ r , ω r three terminals of the rotor winding V as (t), V bs (t), V cs (t), V xs (t), V ys (t), V zs (t) stator terminal voltages of phases A, ψ, ω, X, Y, Z T t torque developed by wind turbine J moment of inertia ψ damping coefficient

Postfault Operation of Five-Phase Induction Machine With Minimum Total Losses Under Single Open-Phase Fault

“…Interestingly enough, no difference has been found in the optimum gains over the whole torque range. This conclusion may be explained by (10). For conventional ML, the stator loss is minimized when = 0.…”

“…For conventional ML, the stator loss is minimized when = 0. From (10), by setting = 0, the corresponding rotor current component will also be zero, which minimizes the copper losses in both rotor and stator circuits. Hence, including/discarding the effect of the rotor and core losses on the optimal current calculations under postfault operation has nothing to do with the optimal reference currents derived in the available literature.…”

“…The synchronous speeds and rotor slip speeds for both subspaces are determined using (7) and (8). For a given matrix (obtained from the optimization algorithm), the sequence components of the rotor currents are calculated based on (9) and (10). The core losses could then be obtained using (13).…”

“…Incorporating wind energy into distribution systems may have various benefits like minimizing power losses and increasing efficiency [7][8][9]. Multiphase machines research directed towards high power and high reliability wind energy systems (WESs) has benefited from the growing interest in wind energy [10,11]. Machine fault tolerance, which is defined as the ability of the machine to continue running under fault conditions, is possible with multiphase machine drive systems due to their extra degrees of freedom as a consequence of increasing the number of phases.…”

Modeling and analysis of novel six‐phase DFIG through asymmetrical winding structure for disperse generation

“…The proposed ASPDFIG has many advantages such as high reliability (more reliable under faulty conditions when one or two or more phases fails to compare to the conventional three phase DFIG), low torque pulsation, low per phase current, lower insulation cost, low environmental impact, less area impact, high quality of power production, low harmonic contents in voltage, current and frequency etc. [23][24][25] Further, the proposed machine is easily extendable to a higher number of phases (9,12,15).…”