This paper presents the design and implementation of Modular Multilevel Inverter (MMI) to control the Induction Motor (IM) drive using intelligent techniques towards marine water pumping applications. The proposed inverter is of eleven levels and has the ability to control the speed of an IM drive which is fed from solar photovoltaics. It is estimated that the energy consumed by pumping schemes in an onboard ship is nearly 50% of the total energy. Considering this fact, this paper investigates and validates the proposed control design with reduced complexity intended for marine water pumping system employing an induction motor (IM) drive and MMI. The analysis of inverter is carried out with Proportional-Integral (PI) and Fuzzy Logic (FL) based controllers for improving the performance. A comparative analysis has been made with respect to better robustness in terms of peak overshoot, settling time of the controller and Total Harmonic Distortion (THD) of the inverter. Simulations are undertaken in MATLAB/Simulink and the detailed experimental implementation is conducted with Field Programmable Gate Array (FPGA). The results thus obtained are utilized to analyze the controller performance, improved inverter output voltage, reliable induction motor speed control and power quality improvement by reduction of harmonics. The novelty of the proposed control scheme is the design and integration of MMI, IM drive and intelligent controller exclusively for marine water pumping applications.
- Field programmable gate array
- Fuzzy logic controller
- Induction motor drive
- Modular multilevel inverter
- Total harmonic distortion
Figure 1. Schematic Diagram Of The Proposed 11-Level Inverter.
EXPECTED SIMULATION RESULTS:
Figure 2. Speed Response Of Pi Controller At 1000 Rpm.
Figure 3. Speed Response Of Flc At 1000 Rpm.
Figure 4. Harmonic Analysis With Pi Controller.
Figure 5. Harmonic Analysis With Fl Controller.
Figure 6. Output Voltage Waveform Of An 11 Level Inverter.
The relevance of the proposed work is to provide high quality of input power to the inverter drive pertaining to marine water pumping applications. A solar PV fed MMI for speed control of induction motor drive has been examined at steady state and dynamic behaviors to investigate its suitability for water pumping system intended for the marine applications. The solar PV array is connected with the proposed inverter when is then fed to an induction motor. The motor speed is sensed and feedback is given to the controller for generating optimal PWM pulses for the inverter switches. The motor is started gradually and the speed is increased to achieve reference speed with aid of PI and FL based controllers. The performance of PI and FL controllers for a feasible operation is verified and results are compared in both simulation and experiment. The results ensure that the FL based controller provides fast settling time and reduced harmonics when compared with the PI controller. The main impact of the proposed control scheme is to reduce the steady-state error of the induction motor speed control and deteriorate harmonics at the output voltage of modular multilevel inverter. On considering the number of components required for the proposed MMI, the Table 3 illustrates the comparative analysis on the number of semiconductor switches required for the design of MMI along with those inverters available in the literature.
The source, converter, load, controller and grid are the major components of a DC microgrid. A microgrid is normally referred as a standalone autonomous system to generate power by the community and for the community regions. In the proposed system, the entire component cited for DC microgrid is present and performs its function effectively. The appropriate estimation of power generated and power used is the future scope.
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