Sinusoidal Pulse Width Modulation Research Articles

Implementation of a modified carrier-based PWM technique for a cascaded MLI using DSP microcontroller

<p><span lang="EN-US">A multi-level converter is a power electronic device desired to generate a desired AC voltage level using several introduced DC voltages, the output voltage of the converter is characterized by a low harmonic content (THD) compared to conventional inverters. The adopted innovative design permits the independent control of PV modules, enabling, in this way, to operate independently and won’t be very affected by intermittence. Additionally in this paper, a new control strategy based on sinusoidal pulse width modulation (SPWM) technique is analyzed for cascaded H-Bridge inverter. In this new technique, separate modified carriers are used for each H-Bridge (HB). Multiple-carrier SPWM is used with the new control SPWM technique. Those carriers are being implemented with diverse sinusoidal dispositions phase disposition (PD), phase opposition and disposition (POD), alternative opposition and disposition (APOD), and with altered frequencies. Experimental results are obtained while using different operating conditions.</span></p>

Modeling and Simulation of Marine PV Inverter System Based on MPPT Algorithm

Under the influence of the policy of low carbon development, the development of new energy ships is receiving wide attention. Aiming at the fluctuation of the ship power grid caused by the intermittent and random nature of the PV power generation system, this paper builds a set of ship PV power generation microgrid system models based on the Matlab/Simulink simulation platform. Under the conditions of ambient temperature, light intensity, and other factors, the front-stage Boost circuit uses the MPPT conductance increment method to obtain the maximum power point of the PV module. The rear-stage inverter uses SPWM (sinusoidal pulse width modulation) inverter control in the rear stage to observe the output effect under different solar radiance, and the system is also designed to automatically switch the DC load when the light intensity is too low, which reduces the system energy loss and improves the operation efficiency of the marine PV system.

A New Level Shifted Carrier Based PWM Technique for a Cascaded Multilevel Inverter Based Induction Motor Drive

The pulse width modulation (PWM) techniques are becoming the game changer for multi-pulse power converter fed multilevel inverter-based induction motor drive (IMD) due to their significant impacts on power quality. In this paper, a new level shifted carrier-based PWM technique is proposed for a 5-level cascaded H-bridge (CHB) multilevel inverter driven by a 36-pulse ac-dc converter based IMD. To meet the power quality demand of IEEE-519 at grid side, a modular transformer is used, and the transformer is coupled to form a 36-pulse ac-dc converter. A 5-level CHB multilevel inverter is utilized on the motor side, which uses the proposed carrier based PWM technique for switching action to ensure superior performance of the IMD. The proposed PWM technique is named as third-harmonic injected inverted sinusoidal carrier PWM (THI2SCPWM), which utilizes 3 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">rd</sup> harmonic injection principle with inverted sinusoidal signal to form the proposed carrier signal. The 5-level CHB inverter used in the IMD shows less power loss and total harmonic distortion (THD) with the proposed THI2SCPWM technique. Moreover, the IMD with the THI2SCPWM shows low stator voltage THD, stator current THD, and smooth dynamic response. Apart from these, the THI2SCPWM mitigates the torque ripple of the IMD. The motor drive system with the THI2SCPWM technique is modeled and its performance is simulated on MATLAB/Simulink environment. A scaled down experimental setup is utilized to validate the superiority of the proposed PWM technique.

Carrier Phase Shift Method of SPWM for Concurrent Wired and Wireless Power Transfer Systems

This paper presents an approach for concurrent power transfer to wired and wireless systems using just a single inverter. The approach utilizes a novel carrier phase-shift (CPS) method that independently controls the inverter output voltages at the fundamental and switching frequencies. This proposed method can be a cost-effective solution to wireless power transfer (WPT) systems used in contactless slip rings (CSR), which transfer power to auxiliary loads such as sensors, radars, and IoT devices. There are two separate converters in conventional CSR systems: one is for the motor drive, and the other is for the WPT system. It is proposed that the switching harmonics of the motor drive can also be utilized to excite the WPT system while the low-frequency component can still be used to drive the motor. In order to control these independently, the CPS method is introduced. The proposed method is investigated analytically for sinusoidal-PWM (SPWM). Then, an experimental setup consisting of a 3-phase 3-wire GaN-based inverter and a 3-phase motor is built. Experimental results show that the WPT and motor systems are operated concurrently, and their powers are controlled independently by the proposed method.

Design a 25-level inverter topology with less switching devices fed by PV systems

&lt;span lang="EN-US"&gt;Multilevel inverter (MLI) technology has lately emerged as one of the most popular solutions for high power and medium voltage energy management. MLIs have many benefits and require more switches for higher levels, which are considered disadvantaged. This could result in large size and extremely expensive cost for the MLI. So, in order to overcome this problem, a new MLI topology is proposed with reduced number of switches. A 25‐level inverter fed by isolated unequal photovoltaic panels as DC sources is chosen in this study. The structure of DC voltages is chosen as (1:1:5:5) Vdc. The proposed approach, which is created using twelve switches, is ideally suited for a high-power application. Multi-carrier with a sinusoidal PWM technique is programmed as a controller. According to the simulation findings, a single-phase system's output voltage and current total harmonic distortion (THD) values are 1.2% and 0.462%, respectively, while a three-phase system's values are 1.07% and 0.342%. These findings prove that the power circuit and investigation were successful.&lt;/span&gt;

A Single-Stage, Multi-Port Hybrid Power Converter Integrating PV and Wind Sources for a Standalone DC System

In this paper, a hybrid PV–wind-source- based multi-port converter focused on a standalone DC system is proposed. The proposed configuration is able to perform simultaneous three-phase AC–DC conversion and DC–DC conversion, ensuring simultaneous power extraction from these combined sources. The proposed converter is a single-stage converter that enhances dependability and eliminates redundant conversion stages with regard to the earlier configurations for the hybrid PV–wind sources. The operational aspects of the proposed converter are depicted, illustrating the regulation of load voltage and load power because of the dynamic output capability of PV–wind sources. Furthermore, the comprehensive control architecture to govern the concurrent conversion operations with the generation of three-phase modulating signals and duty ratio signal in accordance with the load voltage control is elaborated. Additionally, the modified sinusoidal PWM scheme for the proposed converter is elaborated, showing the unification of three-phase modulating signals and duty ratio signal for the generation of PWM pulses which facilitates the simultaneous power conversion processes. Finally, to validate the suitability of the proposed converter, the performance of the converter under various scenarios is investigated through simulation and experimental case studies.

Comparison of Pulse Width Modulation Techniques for Diode-Clamped and Cascaded Multilevel Inverters

Multilevel inverter technology has become the most significant method of energy conversion from DC to AC for uninterrupted power supply. The quality of the power supply depends on the appearance of harmonics, which is considered a problem that needs to be overcome. This paper demonstrates the use of a new modulation technique to reduce the harmonics in both diode-clamped and cascaded multilevel inverters, examining its Total Harmonic Distortion (THD) compared to other PWM methods. Simulations were carried out in MATLAB/Simulink for five-level diode-clamped and cascaded multilevel inverters. The simulation results of both multilevel inverters using the sinusoidal PWM, modified reference PWM, modified carrier PWM, and modified reference and modified carrier PWM methods showed that the latter had the best THD performance for both inverter types, especially for the cascaded multilevel inverter.

Design and Implementation of multi-level inverter for PV system with various DC Sources

Multilevel inverters (MLI) are now favored over conventional transformers due to higher output voltage levels and lower harmonic distortions. In this study, a 45-level and 39-level inverter with lower power switchgear number was constructed. The 16-switch single-phase MLI inverter is generated, simulated, and used realistically. The simulation system uses a control method called sinusoidal pulse width modulation (SPWM). The output voltage from the simulation includes total harmonic distortion (THD). THD values of 45 and 39 level output voltage simulation are 2.59% and 2.98% respectively. The system has been designed and tested practically without load? The THD value was 2.69% for 45-level and 3.13% for 39-level. These results demonstrate that the proposed MLI circuit and SPWM controller were successful in achieving the necessary voltage level and THD decreased when level increased.

Design of PFC converter with stand-alone inverter for microgrid applications

The proposed topology is used to connect a single-phase and a three-phase renewable energy resources to the grid. The single-phase source is coupled to a single-phase PFC boost converter, which enhances the input PF utilizing two feedback loops: outer voltage loop control and inner current loop control. The basic hightlight is to study the PFC converter in microgrid application where renewables are integrated with the systems. The basic aim is to observe the overall performance of the converters with various disturbances such as load variations, etc. Here, the single-phase and three-phase stand-alone inverter is used to get the the output of the PFC boost converters. A symmetrical sinusoidal output voltage waveform should be produced and maintained by the inverter. The three-phase source is also coupled to a PFC buck converter, which enhances the input PF utilizing two feedback loops: outer voltage loop control and inner current loop control. The single-phase stand-alone inverter receives the output of the PFC buck converter. The transformer receives the outputs of both the inverters as it is a multi-winding high-frequency transformer and offers isolation between the grid and the source. The pulses for the switches in the single-phase inverter coupled stand-alone system were generated using a sinusoidal pulse width modulation approach. Both the PI controllers are implemented to maintain the regulations. The simulation results are achieved by varying the load, maintaining a constant voltage, and observing whether the current varies as the load changes. It also provides the efficacy of the study.

Backstepping Control of NPC Multilevel Converter Interfacing AC and DC Microgrids

This work introduces modified backstepping methods to design controllers for neutral point clamped (NPC) converters interfacing a DC/AC microgrid. The modified backstepping controllers are derived from a proper converter model, represented in dq coordinates, and are designed to regulate the DC voltage and to balance the two NPC converter DC capacitor voltages through a DC offset in the sinusoidal pulse width modulation (SPWM) carriers. The averaged and separated dynamics backstepping controllers also enforce nearly sinusoidal AC currents at a given power factor. The two proposed NPC converter controllers are evaluated through MATLAB/Simulink simulations and experimental implementation using a laboratory prototype. Simulations and experimental results show that the two modified backstepping controllers regulate the microgrid DC voltage in steady state and in transient operation, even with load disturbances or DC voltage reference changes, while enforcing nearly AC sinusoidal currents at a given power factor or injected reactive power. The modified backstepping-controlled NPC converter is bidirectional, converting energy from DC renewable energy sources or storage systems to AC or charging storage systems from AC. The results also highlight the effective balancing of the NPC DC capacitor voltages.

A Single-Stage Closed Loop Control of SC-Based Inverter

This work presents a closed loop five-Level grid-connected inverter. The inverter is based on the switched capacitor approach. The suggested architecture has a lower number of components and is able to maintain a voltage balance across the various capacitors in the system. The construction that has been presented offers a number of benefits, including the capacity to produce five-level voltage output, lower current THD, and enhanced efficiency. Additionally, leakage-current in the circuit is eliminated due to the common grounding configuration. The current injected into the grid is controlled by a PI controller. As a result, a carefully controlled current of the desired quality can be injected into the system using just one renewable energy source. In order to test the suggested topology, the level-shifted sinusoidal pulse width modulation scheme is adopted. The design of switched capacitors as well as the computation of power loss in switches is offered. The performance of this suggested inverter topology is evaluated in comparison to other topologies that are recently presented in the literature. In addition, the power losses and efficiency are calculated using thermal modeling of the topology in PLECS software. MATLAB-2018/Simulink is used to simulate and analyze the PV-connected grid system.

Experimental study of mutual effects of high carrier frequency, dead-time and control sample time on IPMSM core loss under SiC inverter excitation

This paper experimentally analyzes the core loss characteristics of an interior permanent magnet synchronous motor (IPMSM) excited by a SiC inverter with the sinusoidal pulse-width modulation (PWM) and high modulation index of 1.1 considering the mutual effects of the high carrier frequencies of up to 200 kHz, different dead-times of 250 and 1000 ns, control sample times of 100–1000 μs, and stator core temperature. The experimental IPMSM drive system is operated in load condition with a torque of 1.05 Nm and rotational velocity of 1500 rpm. Furthermore, the ringing phenomenon and rise time in the motor voltage are measured and analyzed using a high-resolution oscilloscope that has a superior sampling rate of up to 5 giga-samples per second (GS/s), which helps to thoroughly examine the impact of the SiC inverter excitation on the motor core loss. The relations of the total harmonic distortion (THD) of the measured motor voltage and current and the distortions in the magnetic flux density through the stator core to the IPMSM core loss properties are also evaluated. Lastly, explanations and insights based on physics of the obtained results are presented.

Theoretical Study of Rampwise DPWM Technique to Reduce Motor Acoustic Noise

Motor acoustic noise generated near living environments such as elevators and electric vehicles may cause discomfort. In order to reduce the acoustic noise, the switching frequency is set to the high side of the audible frequency range. In this case, however, the switching loss is increased. The conventional discontinuous PWM (DPWM) method is widely used since it can reduce the switching loss drastically. However, it produces larger acoustic noise than the conventional sinusoidal PWM method. The authors have previously proposed Rampwise DPWM techniqueh which can reduce both acoustic noise and switching loss. In this paper, the line-line voltage with the proposed Rampwise DPWM technique is expanded into a real-valued Fourier series, and the frequency characteristics are analyzed. It is theoretically confirmed that the rampwise part in the Rampwise DPWM technique can achieve reduction of motor acoustic noise. Furthermore, the reduction effect of motor acoustic noise with the Rampwise DPWM technique is theoretically and experimentally verified.

Hybrid Switching Control-Based DC to AC Inverter for Microgrid Using Renewable Energy Sources

Hybrid switching control-based direct current (DC) to alternating current (AC) inverter is a method of controlling the flow of power from DC sources such as solar panels or wind turbines to AC loads in a microgrid. In a microgrid, renewable energy sources are often used to supplement traditional sources of energy and improve overall energy efficiency. To simulate micro-grid systems, an effective three-legged IGBT inverter has been developed using Matlab R2016a/Simulink. The inverter switches are controlled by a pulse controller, which creates the switching gate pulses. This work models the output voltage and current waveforms of the three-phase 180° voltage source inverter that supplies nonlinear loads. To lower the total harmonic distortion (THD) of the current and voltage outputs of the three-phase voltage source converter (VSC), a filter circuit and a two-level pulse width modulation (PWM) generator have been presented. This pulse-width modulation generator compares the modulating signal and a high-frequency triangular carrier wave. Sinusoidal pulse width modulation (SPWM) is used for PWM control. Moreover, the hybrid switching control-based DC-to-AC inverter utilizes a combination of pulse width modulation (PWM) and hysteresis current control techniques to maintain a constant AC output voltage and frequency. PWM control is used to regulate the voltage, while hysteresis current control is used to regulate the current. Additionally, an inductor-capacitor-inductor (LCL) filter is used to improve the stability of the power converter by providing a damping effect on the system. Overall, the LCL filter is a versatile and effective tool for improving the performance of power inverters, especially in applications where high efficiency and low harmonic distortion are important. IUBAT Review—A Multidisciplinary Academic Journal, 6 (1): 25-46

A Control Scheme for a Quasi-Z Source Three-Phase Inverter

This paper presents a novel control scheme for a three-phase quasi-z source inverter (qZSI) using a capacitor voltage and input current-based sinusoidal pulse width modulation (SPWM) technique. The proposed scheme combines the advantages of both qZSI and SPWM techniques to achieve improved performance. The SPWM technique utilizes a sinusoidal modulation signal, which is compared with a high-frequency triangular carrier wave and two shoot-through (ST) references to determine the switching states for the three-phase qZSI. The positive and negative ST references are obtained from the capacitor voltages and input current, allowing for control of the DC bus voltage and ST states of the inverter. Additionally, the proposed control scheme generates the three-phase modulation signal through decoupling control in the dq reference frame. The detailed analysis of the control scheme includes its operating principle, transient state, steady-state responses, and the effects of parameter variations. Simulation studies are conducted using MATLAB/Simulink to assess the performance of the three-phase qZSI under the proposed control scheme. The simulation results demonstrate the effectiveness of the control scheme in terms of output voltage quality, DC bus voltage control, and robustness against reference variations. Overall, the proposed capacitor voltage and input current-based SPWM control scheme for the three-phase qZSI shows promising performance improvements and robustness, as confirmed through comprehensive simulation studies.

Design and Measurement of a Frequency Converter with SPWM Modulation of Output Voltage for a Two-Phase Induction Motor

This paper deals with the design, implementation, and measurements of a frequency converter with bipolar sinusoidal pulse width modulation (SPWM) of output voltage for two-phase induction motors. The paper is dedicated to an analysis of the operation of a two-phase frequency converter and its implementation. The inverter has a single-phase H-bridge topology with split DC link and bipolar switching to minimise the number of components. Insulated gate bipolar transistors (IGBTs) are used in the realisation of the inverter power section. The inverter is controlled using a digital signal processor (DSP) TMS320F28335. Measurements with a 0.12 kW two-phase induction motor were performed to verify the correct operation of the inverter. The influence of the switching frequency on the motor current ripple is measured for frequencies of the first harmonic up to 100 Hz.

Performance Evaluation of Brushless Direct Current Motor Control Methods through Low-Cost Microcontroller-Based Real-Time Experiments

Brushless direct current (BLDC) motors are high efficiency synchronous motors that are employed in a variety of applications due to prominent features such as long operational life, low maintenance requirements, and great dynamic response. BLDC motors are driven by energizing the motor stator windings with an inverter circuit. To commute the inverter switches, the trapezoidal (120°) method is generally used by considering the back electromagnetic force induced on unenergized phase of BLDC. Furthermore, depending on the application requirements, alternative commutation modes (CM) such as 180°, 150°, and sinusoidal-based approaches are utilized. In the literature, the performance comparison of some CMs was studied for two-phase on operation and three-phase on operation mode as a switching pattern. However, only a few research assessed the performance of two or three commutation modes simultaneously. In this study, the performance comparison of pulse width modulation (PWM) based commutation modes are examined by considering 120°, 180°, 150° modes, and sinusoidal PWM. In this scope, it is the first time that direct digital synthesis (DDS) is addressed as a BLDC control algorithm in a performance comparison study. In experimental studies, a simple and a low-cost drive circuit is designed to acquire the case results. According to the results, the proposed DDS-based sine commutation method is more efficient than other commutation methods and it has lower power consumption at both low and high speeds also a wider operable speed range.

Mitigation of Common Mode Voltage in Induction Motor Employing Multilevel Inverter

Induction motor (IM) is a usually a constant speed motor. The Basic technique used to control and run the machine in variable speed drive application can be obtained by two level inverters, which can be controlled digitally with the help of microcontroller using sinusoidal pulse width modulation method. Thereby at the star terminal point of the load there is a voltage existed with respect to system ground. Hence it is defined as “common mode voltage”. Due to the common mode voltage, there is an electromagnetic interference that is induced. Thereby it causes lot of disturbance to the communication and electronic equipment’s, which are nearby to the system. The common mode voltage can be reduced with the help of high-level inverter that can be used for example two-level, three-level, four-level inverters etc. In this proposed system we are reducing the common mode voltage by using two level inverter &amp; three level inverter. In this paper, mitigation of CMV is simulated through MATLAB and implemented by hardware setup.

Design and Harmonic Elimination of sinusoidal pulse width modulation (SPWM) Based Five Level Cascaded H-Bridge Multilevel Inverter for Photovoltaic System for Educational Purposes

In this modern era, the electrical power system faces a shortage of fossil fuel-based energy sources. To overcome this problem, people more focus on giving towards renewable energy sources like solar energy, wind energy, and nuclear energy sources. This also can be used to overcome global warming and reduce pollution by fossil fuels. This study used a photovoltaic (PV) array to give supply to the Multilevel Inverter (MLI) with different irradiance values, which can be used for educational purposes. The sinusoidal pulse width modulation (SPWM) method is used here to control the converter. SPWM technique is the easiest technique than the other types of pulse width modulation (PWM) technique. In this technique the switching loss is very low, therefore efficiency is high. After the simulation, the output waveforms are similar to the sinusoidal waveform for the resistive load. In this topology, after simulation, the total harmonic distortion (THD) contents were found to be less by using an LC filter. The model is simulated in MATLAB/Simulink. The analysis of output voltage waveforms is discussed with the reduced THD.

High-Precision Dead-Time Intellectual Property Core and Its Compensation for Inverters

In the inverter circuit, there exists a specific on-off time in each power transistor. As such, to prevent a short circuit of the two switch devices on the upper and lower bridge arms, a specific dead time must be set in the pulse width modulation (PWM) and the sinusoidal pulse width modulation (SPWM) signals. In this paper, an intellectual property (IP) core that can introduce a high-precision dead time of arbitrary length into PWM or SPWM signals of the inverter is designed to increase the precision, convenience and generalization of dead time control, resulting in a boosted control accuracy of up to 10 ns. Moreover, the added Avalon bus enables IP cores to be accessed by the field programmable gate array (FPGA) processor in a standard manner and multiple IP cores of the same class can be easily incorporated. In addition, an application for setting and compensating for dead time in a three-phase inverter based on system on programmable chip (SOPC) technology is presented. With the Nios II CPU as its core, the system adopts the mean voltage compensation method to calculate the compensation voltage, and performs dead-time compensation in a feed-forward manner. The three dead-time IP cores are controlled by Avalon bus. These allow the dead time of three groups of power transistors to be accurately controlled and flexibly adjusted. The system also features the master computer communication function while boasting the advantages of flexible control, high precision and low cost.