This paper focusses on the time response performance aspects and control-signal magnitude aspects of controller design.
Recently, a flux magnitude and angle controller (FMAC) scheme is put forward for DFIGs, by which the terminal voltage and stator power can be controlled via the magnitude and angle of the rotor flux vector decouply [45].
The proposed controller uses magnitude and phase compensation to eliminate the errors associated with the nonlinear distortion of analog devices in the ANC system, and hence, to improve the noise reduction performance.
It can be seen from the Fig. 3 that the input electric power of IM consists of two parts: ① the power from network, which is affected by the terminal voltage vector, the transmission line and the characteristics of capacitor; ② the power from the STATCOM, which is closely related to the terminal voltage magnitude and the corresponding controller.
However, most servo controllers are based on integer processors for machine tools, and the integer numbers entering into a servo tuning interface often do not directly reflect the magnitudes of the actual controller parameters, impairing the virtual tuning.
In order to find the appropriate parameters of this controller, the compromise between magnitude of control signal and convergence speed is quantified by using a quadratic performance index.
Furthermore, it is computed for a tracking problem by minimizing its magnitude among feasible sets of controller gains satisfying a quadratic tracking condition in the sense that tracking errors are norm-bounded.
Both the simulation and the experimental results indicate that with the proposed controller, the vibration magnitude caused by a rough road can be greatly reduced, and the driver ride comfort is greatly improved.
The controllers are examined using the IEEE 123-bus feeder distribution system, and it is found that the controllers can effectively mitigate voltage magnitude fluctuations and that the appropriate choice of controller depends on the performance metrics of interest.
As discussed, in this strategy, the output voltage phase angle is determined by active power controller and the output voltage magnitude is controlled by the reactive power controller.
