Programmed Pulse Width Modulation Research Articles

GaN-Based Dual-Mode Wireless Power Transfer Using Multifrequency Programmed Pulse Width Modulation

Multifrequency wireless power transfer (WPT) is advantageous in facilitating compatibility with different WPT standards. However, implementing a multifrequency transmitter often requires compromises in system size, complexity, power transfer capability, or output regulation. In this paper, a single-inverter-based dual-mode WPT system is proposed. The system employs a multifrequency programmed pulse width modulation scheme. This multifrequency modulated inverter can simultaneously generate and regulate 100-kHz and 6.78-MHz outputs, or multiple frequencies within ranges of 87–300 kHz, which facilitates the development of multistandard WPT technology for consumer electronics. The principle of the proposed modulation is illustrated, where two different frequencies are concurrently modulated using a programmed pulse train of square waveforms for power delivery, while eliminating certain harmonics. Design tradeoffs and constraints are examined through analytical circuit models. Finally, experimental results are provided to verify the method on a gallium-nitride-based WPT prototype.

A Novel Efficient Sine Wave Inverter with Custom Programmed PWM and Intelligent Control

This article presents an efficient design of a pure sine wave inverter which results in an electronic design with reduced losses. The proposed design incorporates the generation of custom programmed pulse width modulation (CPPWM) waveforms; the gate drive signals that are customized for the harmonic elimination from the output voltage, maximizing the fundamental component and resulting in an efficient electronic circuit design as compared to the traditional techniques in terms of the switching losses and the filtering energy losses. The CPPWM signals are digitally programmed in a micro-controller. The inverter realization is followed by an intelligent compensator design for the regulation of output voltage amplitude. The proposed algorithm self-adjusts its parameters in response to the load current and voltage amplitude variations hence resulting in an improved performance. The simulation results of the control algorithm are presented. The experimental validation of the theoretically investigated controller is also presented by implementing a discrete time realization of the control algorithm using digital controller interfaced in real time with MATLAB®/Simulink®. The hardware results are elucidated. The feasibility of the proposed controller is theoretically and experimentally verified by its efficiency compared to the classical techniques, the available tunable parameters in the controller structure and the immense flexibility in the attainable closed loop dynamics.

A Novel Efficient Sine Wave Inverter with Custom Programmed PWM and Intelligent Control

This article presents an efficient design of a pure sine wave inverter which results in an electronic design with reduced losses. The proposed design incorporates the generation of custom programmed pulse width modulation (CPPWM) waveforms; the gate drive signals that are customized for the harmonic elimination from the output voltage, maximizing the fundamental component and resulting in an efficient electronic circuit design as compared to the traditional techniques in terms of the switching losses and the filtering energy losses. The CPPWM signals are digitally programmed in a micro-controller. The inverter realization is followed by an intelligent compensator design for the regulation of output voltage amplitude. The proposed algorithm self-adjusts its parameters in response to the load current and voltage amplitude variations hence resulting in an improved performance. The simulation results of the control algorithm are presented. The experimental validation of the theoretically investigated controller is also presented by implementing a discrete time realization of the control algorithm using digital controller interfaced in real time with MATLAB®/Simulink®. The hardware results are elucidated. The feasibility of the proposed controller is theoretically and experimentally verified by its efficiency compared to the classical techniques, the available tunable parameters in the controller structure and the immense flexibility in the attainable closed loop dynamics.

Application of improved firefly algorithm for programmed PWM in multilevel inverter with adjustable DC sources

Programmed pulse width modulation is an optimized pulse width modulation which is particularly applicable for high-power applications where the power losses must be kept below firm limits. Based on the offline estimation, it is capable of pre programming the harmonic profile of the output waveform over a range of modulation indices by eliminating some lower order harmonics. In this paper, improved firefly algorithm (FA) is applied to determine the optimum switching angles for the 11- level cascaded H bridge multilevel inverter (MLI) with adjustable DC sources in order to eliminate pre specified lower order harmonics and to achieve the desired fundamental voltage. Though number of optimization algorithms is available for the estimation of switching angles, Firefly algorithm takes least computation time and surpasses all other 11 metaheuristic Algorithms. The algorithm and the model are developed using MATLAB and the validity of the simulation is confirmed by an experimental setup using FPGA Spartan 6A DSP. Results are compared with the results obtained using particle swarm optimization (PSO) and artificial bee colony algorithm (ABCA) and it is proved that the proposed method offers reduced total harmonic distortion (THD) with less computation period.

Rapid Design and Implementation of AC-DC Converter-based dsPIC Blockset Using Differential Evolution Algorithm

Programmed PWM techniques are some of the control methods used in voltage/current source converters. However, challenges are the task of defining and solving a set of nonlinear transcendental equations in order to obtain the switching angles. The paper presents an efficient Differential Evolution (DE) algorithm that significantly reduces the computational burden resulting in a fast convergence. The design procedure of a Programmed Pulse Width Modulation (PPWM) rectifier using Matlab/Simulink Blockset and code generation tools for Microchip dsPIC Digital Signal Controller (DSC) is also presented. The proposed approach follows the standard practice to utilize Matlab/ Simulink and related toolboxes as the design framework to develop a rapid prototype system in a reliable procedure. The design procedure uses Simulink model of the AC-DC converter system, drive circuitry, Matlab Real-Time Workshop, and Microchip MPLAB IDE development tools. The generated and self-developed codes on dsPIC 30F4013 are tested with the dsPICDEM 2 Development Board. The output rectifier waveform and spectrum results from simulation and experimental DSC PPWM are presented.

Modified shuffled-frog-leaping algorithm in company with neural networks for harmonic distortion minimisation in real-time control applications of programmed pulse-width modulation inverters

Harmonic pollution minimisation in voltage-source programmed pulse-width modulation (PPWM) inverters is defined as a time-limited optimisation problem in real-time applications with variable DC sources. In order to obtain minimum total harmonic distortion (THD) as the objective function, shuffled-frog-leaping algorithm (SFLA) is modified and employed to calculate the switching angles and compared with non-linear programming as a traditional optimisation method. In addition, particle swarm optimisation and three of its modified versions as popular evolutionary optimisation algorithms are employed to ensure the capability of the proposed optimisation method. Moreover, modified sinusoidal PWM (MSPWM) THD is compared with PPWM THD. Furthermore, as the DC bus voltage in some applications might have high variations (in amplitude or frequency of fluctuations) in a short time, to acquire adequate response speed to this variation of DC source of inverters in real-time control applications, a neural network (NN) is trained by the off-line calculated results of MSFLA for various desired modulation indexes (various DC voltages). Simulation results demonstrate the accurate and high-speed response of the designed NN. The main contribution of this study is to provide a fast accurate method which can track the variation of DC source of inverters with high-quality solutions in real-time control applications.

Programmed pulsewidth modulated waveforms for electromagnetic interference mitigation in DC-DC converters

The regular switching action of a pulse-width-modulated (PWM) circuit generates conducted and radiated electromagnetic interference (EMI) and may also generate acoustical disturbances. Programmed pulsewidth modulation techniques have been applied using various methods to control harmonics inherent in switched power circuits. A method for generating an optimal programmed switching waveform for a DC-DC converter is presented. This switching waveform is optimized to reduce the amplitude of harmonic peaks in the EMI generated by the converter. Experimental results, a brief discussion of sensitivity, and a practical implementation of a circuit to generate the PWM waveform are given. >

Optimal power control strategies for neutral point clamped (NPC) inverter topology

A programmed pulsewidth modulation (PWM) technique for selectively eliminating several lower-order harmonics at the output of a neutral point clamped (NPC) inverter topology is investigated. The switching function approach is utilized to derive relevant analytical expressions for input/output variables. A thorough evaluation of the NPC inverter topology based on the switching function approach is described. Optimal power control strategies for an NPC inverter employing programmed PWM patterns are proposed. For a constant-frequency variable-voltage NPC inverter power supply, the proposed strategy is to maintain a minimum specified total harmonic distortion employing a low-output impedance filter. In the case of an NPC inverter powering an AC motor drive, the proposed strategy is to maintain a minimum specified harmonic current factor. The proposed power control strategies are achieved without substantial increase in inverter switching frequency and are therefore suitable for high-power applications employing gate-turn-off-thyristor (GTO) type devices. >

A three-phase inverter with selectively programmed pulse width modulation for an electric vehicle with battery supply

The development and evaluation of a 15 kVA inverter with 144 V battery voltage and pulse width modulation for an electric-hydraulic hybrid road vehicle are discussed. The vehicle is equipped with a squirrel cage induction traction machine. This article covers the configuration of the inverter, the use of integrated bipolar Darlington power transistors, protection of the power switches, base drive of the transistors and control of the inverter. The inverter and drive energy efficiency are evaluated, and the installation of the inverter in the vehicle is discussed.