ABSTRACT:
In this paper, a Ziegler-Nichols (Z-N) based PID
plus fuzzy logic control (FLC) scheme is proposed for speed control of a direct
field-oriented induction motor (DFOIM). The Z-N PID is adopted because its
parameter values can be chosen using a simple and useful rule of thumb. The FLC
is connected to the PID controller for enhancing robust performance in both
dynamic transient and steady-state periods. The FLC is developed based on the
output of the PID controller, and the output of the FLC is the torque command
of the DFCIM. The complete closed-loop speed control scheme is implemented for
the laboratory 0.14-hp squirrel-cage induction motor. Simulation results demonstrate
that the proposed Z-N PID+FLC scheme can lead to desirable robust speed
tracking performance under load torque disturbances.
KEYWORDS:
1.
Speed control
2.
Hybrid PID plus fuzzy controller
3.
Induction
motor
4.
Ziegler-Nichols method
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Figure
1.The block diagram of speed control of a DFOIM
CONCLUSION:
In
this paper, a novel hybrid modified Z-N PID+FLC-based speed control of a DFOIM
has been presented. The proposed controller has exhibited the combined
advantages of a PID controller and a FLC. Specifically, it can improve the
stability, the transient response and load disturbance rejection of speed control
of a DFOIM. The complete DFOIM drive incorporating the proposed controller has
been implemented in real time using a MRC-6810 AD/DA servo control card for the
Nikki Denso NA21-3F 0.14Hp induction motor. The fuzzy logic and only with three
membership functions are used for each input and output for low computational
burden, which can achieve satisfactory results. Simulation and experiment
results have illustrated that the proposed controller scheme has a good and robust
tracking performance. As suggested in [15] that a modified Z-N PID can perform
better than a Z-N PID, our future effort will focus on how to further improve
the performance of the proposed controller herein by incorporating a modified
Z-N PID.
REFERENCES:
[1]F.
Blaschke, “The principle of field orientation as applied to the new transvektor
closed-loop control system for rotating-field machines,” Siemens Review, Vol.
39, No. 5, pp.217-220, 1972.
[2]Y.
F. Tang and L. Xu, “Fuzzy logic application for intelligent control of a
variable speed drive,” IEEE Trans. Energy Conversion, Vol. 9, No. 4,
Dec. 1994.
[3]Z.
Zhang, et al., ‘‘Sensorless direct field-oriented control of three-phase
induction motors based on ‘‘sliding mode’’ for washing- machine drive
applications,’’ IEEE Trans. Industry Applications, Vol. 42, No.
3, May/June. 2006.
[4]I.
Miki, et al. “Vector control of induction motor with fuzzy PI controller,” IEEE
Conf., IAS Annu. Meeting 1991, Vol. 1, pp.341-346
