Padmanaban Sanjeevikumar

Multi-phase multi-level AC motor drive based on four three-phase two-level inverters

A novel multi-phase multi-level ac motor drive is analyzed in this paper. The proposed scheme is based on four conventional 2-level three-phase voltage source inverters (VSIs) supplying the open-end windings of a dual three-phase motor (asymmetric six-phase machine), quadrupling the power capability of a single VSI with given voltage and current ratings. The proposed control algorithm is able to generate multi-level voltage waveforms, equivalent to the ones of a 3-level inverter, and to share the total motor power among the four dc sources within each switching period. The proposed ac motor drive has been numerically implemented and a complete set of simulation results is given to prove the effectiveness of the whole scheme.

Experimental investigation of fault-tolerant control strategies for quad-inverter converters

Fault-tolerant control strategies for quad-inverter based multiphase-multilevel converters are proposed and experimentally verified in this paper. Explicitly, the conversion scheme consists of four standard 2-level three-phase voltage source inverters (VSIs), able to supply a dual three-phase induction motor in open-end stator winding configuration (asymmetric six-phase machine), quadrupling the utility power of a single VSI within given voltage and current ratings. The developed modulation scheme has the capability to generate multilevel output voltage waveforms in healthy conditions, equivalent to the one of a 3-level VSI, and to share the total motor power among the four dc sources in each switching cycle. This sharing potentiality is investigated under post-fault operating conditions, when one VSI completely insulated due to a severe failure on it. In such circumstances, the quad-inverter system can perform with reduced power rating by a proper modulation of the remaining three healthy VSIs. The complete multi-phase-multilevel conversion system with the proposed control algorithm under healthy and post-fault operating conditions has been verified by experimental implementation in open-loop control aspect using two dsp TMS320-F2812 processors with two three-phase passive loads in open-end configuration.

Robust Speed Control of an Induction Motor Drive using Wavelet-fuzzy based Self-tuning Multiresolution Controller

This paper presents a hybrid wavelet-fuzzy based multiresolution (MR) controller for robust speed control of induction motor. The discrete wavelet transform (DWT) is used to decompose the error between the actual speed and command speed of the induction motor drive in to different frequency components. A self-tuning fuzzy logic is used for online tuning of the controller parameters. The proposed controller has the ability of meeting the speed tracking requirements in the closed loop system. The complete indirect field oriented control scheme incorporating the proposed wavelet-fuzzy based MR controller is investigated theoretically and simulated under various dynamic operating conditions. Simulation results are compared with that of conventional PI controller and fuzzy based PI controller. The speed control scheme incorporating the proposed controller is implemented in real time using the digital processor (DSP) control board. Simulation and experimental results validates the effectiveness of the proposed controller over conventional controllers and proves to be more suitable for high performance applications.

Three-phase multilevel inverter configuration for open-winding high power application

This paper work exploits a new dual open-winding three-phase multilevel inverter configuration suitable for high power medium-voltage applications. Modular structure comprised of standard three-phase voltage source inverter (VSI) along with one additional bi-directional semiconductor device (MOSFET/IGBT) per phase and two capacitors with neutral point. Hence, introduces the additional voltage levels in each phase of the VSI. Further, this paper developed a modified single carrier five-level modulation (MSCFM) scheme in such way to overcome the complexity of standard space vector modulations, ready for implementation purpose. Proposed dual-inverter configuration generates multilevel outputs with benefit includes reduced THD and dv/dt in comparison to other dual-inverter topologies. Complete model of the multilevel ac drive is developed with simple MSCFM modulation in Matlab/PLECs numerical software. Preliminary results are provided in this paper confirm the suitability of investigation for real implementation.

High-Voltage High-Frequency Arbitrary Waveform Multilevel Generator for DBD Plasma Actuators

A high-voltage high-frequency single-phase arbitrary waveform voltage generator able to supply a wide range of plasma reactors is proposed in this paper. The generator structure is based on the cascaded H-bridge multilevel (ML) topology, including 24 H-bridge basic modules with the capability of 49 output voltage levels. The individual H-bridge dc supply (600 V) is provided by a flyback converter fed by a low-voltage (12 V) dc battery. This way, the input isolation of the ±14.4 kV maximum output voltage is realized in a simple and effective manner, and a portable device is obtained. The ML generator has been tested by supplying a dielectric barrier discharge (DBD) fluid-dynamic plasma actuator with different voltage waveforms, pointing out a wide and interesting set of results in terms of output plasma currents, and a first comparison has been carried out with respect to a conventional ac sinusoidal generator. A simplified circuit model has been introduced for the DBD plasma actuator, and the whole system has been numerically implemented by Simulink of MATLAB. The simulation results are in good agreement with the experiments.

Quad-inverter configuration for multi-phase multi-level AC motor drives

A novel quad-inverter configuration for multiphase multi-level ac motor drives is analyzed in this paper. The proposed scheme is based on four conventional 2-level three-phase voltage source inverters (VSIs) supplying the open-end windings of a dual three-phase motor (asymmetric six-phase machine), quadrupling the power capability of a single VSI with given voltage and current ratings. The proposed control algorithm is able to generate multi-level voltage waveforms, equivalent to the ones of a 3-level inverter, and to share the total motor power among the four dc sources within each switching period. The whole ac motor drive has been numerically implemented and a complete set of simulation results is given.

Simulation of Processes in Dual Three-Phase System on the Base of Four Inverters with Synchronized Modulation

Novel method of space-vector-based pulse-width modulation (PWM) has been disseminated for synchronous control of four inverters feeding six-phase drive on the base of asymmetrical induction motor which has two sets of windings spatially shifted by 30 electrical degrees. Basic schemes of synchronized PWM, applied for control of four separate voltage-source inverters, allow both continuous phase voltages synchronization in the system and required power sharing between DC sources. Detailed MATLAB-based simulations show a behavior of six-phase system with continuous and discontinuous versions of synchronized PWM.

A simple MPPT algorithm for novel PV power generation system by high output voltage DC-DC boost converter

This paper presents the novel topology of Photo Voltaic (PV) power generation system with simple Maximum Power Point Tracking (MPPT) algorithm in voltage operating mode. Power circuit consists of high output voltage DC-DC boost converter which maximizes the output of PV panel. Usually traditional DC-DC boost converters are used for such application, but they are not the most suitable solution due to output limitation, lower efficiency and require more sensors with complex control algorithm. Further on, the effects of parasitic elements are suppressed, as well as the power transfer efficiency of DC-DC converters for PV integration. Hence, to overcome these difficulties this paper investigates a DC-DC boost converter together with the additional parasitic component within the circuit to provide high output voltages for maximizing the PV power generation. The proposed power system circuit substantially improves the high output-voltage by a simple MPPT closed loop proportional-integral (P-I) controller, and requires only two sensor for feedback needs. The complete numerical model of the converter circuit along with PV MPPT algorithm is developed in numerical simulation (Matlab/Simulink) software. A detailed performance analysis is carried out under both PV panel irradiation (high/low) and load regulation conditions. Numerical results obtained in this paper are in the agreement with the theoretical developments, proving the effectiveness of the proposed topology.

Implementation of Wavelet-Based Robust Differential Control for Electric Vehicle Application

This research letter presents the modeling and simulation of electronic differential, employing a novel wavelet controller for two brushless dc motors. The proposed controller uses discrete wavelet transform to decompose the error between actual and reference speed. Error signal that is actually given by the electronic differential based on throttle and steering angle is decomposed into frequency components. Numerical simulation results are provided for both wavelet and proportional-integral-derivate controllers. In comparison, the proposed wavelet control technique provides greater stability and ensures smooth control of the two back driving wheels.

Analysis of Wavelet Controller for Robustness in Electronic Differential of Electric Vehicles: An Investigation and Numerical Developments

ABSTRACT In road transportation systems, differential plays an important role in preventing the vehicle from slipping on curved tracks. In practice, mechanical differentials are used, but they are bulky because of their increased weight. Moreover, they are not suitable for electric vehicles, especially those employing separate drives for both rear wheels. The electronic differential constitutes recent technological advances in electric vehicle design, enabling better stability and control of a vehicle on curved roads. This article articulates the modeling and simulation of an electronic differential employing a novel wavelet transform controller for two brushless DC motors ensuring drive in two right and left back driving wheels. Further, the proposed work uses a discrete wavelet transform controller to decompose the error between actual and command speed provided by the electronic differential based on throttle and steering angle as the input into frequency components. By scaling these frequency components by their respective gains, the obtained control signal is actually given as input to the motor. To verify the proposal, a set of designed strategies were carried out: a vehicle on a straight road, turning right and turning left. Numerical simulation test results of the controllers are presented and compared for robust performance and stability.