Pulse Width Modulation Signal Research Articles

Comparison of Different Circuit Topology for Generation of PWM Signal with High Power for Electroporation

Electroporation refers to a microbiological method which involves application of electric field to cells for ameliorating the cell membranes permeability, allowing electrode arrays, drugs and chemicals to be inserted into the cells. This process requires HV pulses or signals for creating pores within the cell membrane. As these signals are less effective, nowadays, Pulse Width Modulation (PWM) signals are extensively employed for electroporation. These signals can be exploited for constructing coveted output voltage in power amplifiers and are found to be useful for regulating power devices. Therefore, generation of top quality PWM signals is essential for achieving superior electroporation performance. Different PWM methods are available and circuit topologies employed for generating these waveforms are also different. This paper thus provides an exploratory study of distinct circuit topologies exploited for generating PWM waveforms. The review paper also provides the significance of PWM signals for electroporation. It reviews the existing circuit topologies exploited for PWM signal generation and other related studies. It also presents a circuit for PWM waveform generation. The paper then provides the substantial future directions pertaining to the study. This review article mainly educates the reader regarding existing circuit topologies for PWM signal generation, their characteristics and improvements required for developing better topologies satisfying the requisites of modern applications.

DSP based Hardware-in-the-Loop (HIL) Simulation for GCPV-based DSTATCOM using Frequency Domain Controller

This study presents a comprehensive simulation of digital control applications for a grid-connected photovoltaic (GCPV) system using a Hardware-in-the-Loop (HIL) simulation approach that incorporates a Digital Signal Processor (DSP). The simulation is carried out using the MATLAB Simulink block set and employs a frequency domain controller as the control algorithm. The simulation inputs, which consist of voltage and current sensor readings, are processed by an ADC idealizer block that produces output based on a real-time DSP-based HIL system. The output is then utilized to generate a pulse width modulation (PWM) signal, which drives the voltage source inverter (VSI). The simulation’s primary objective is to demonstrate the simplicity and efficacy of the proposed frequency domain controller design for the GCPV-based DSTATCOM system. The simulation results validate the performance of the controller under various operating conditions, including steady-state, unbalanced loads, variable solar insolation, and day-to-night transitions.

Research of Low Power Humidity Sensor Based on Complementary Metal Oxide Semiconductor Technology in Power Monitoring

With the decrease of the size of semiconductor, the humidity sensor can be miniaturized and integrated by CMOS technology, and the humidity sensor chip can be made in large scale and low cost. In this paper, the technology structure of integrated capacitive humidity sensor chip is designed and fabricated by using UMC40nm semiconductor technology, it provides a reference for realizing the highly integrated technology of humidity sensor. This paper also analyzes the common micro-capacitance detection methods of humidity sensor, and combines the advantages of capacitor charge-discharge and pulse-width output stability, easy modulation and easy digital system interface, etc., a novel CMOS capacitive humidity sensor micro-capacitance detection circuit is designed by using UMC40nm semiconductor technology. The CMOS circuit can convert the change of capacitance into pulse width, in which the pulse width is linear with the capacitance difference, and can produce periodic pulse sequence and output pulse width modulation signal, it can be easily connected with microcontroller or digital system without adding A/D conversion module to increase circuit complexity and power consumption. The circuit not only can detect the micro-capacitance of humidity sensor, but also has the advantages of low power consumption, linearity, high resolution and digitalization.

Performance Evaluation of a Quadcopter by an Optimized Proportional–Integral–Derivative Controller

This paper presents an analysis of a quadcopter’s stability and its sensors’ data reading using an IMU (inertial measurement unit). Firstly, the angular velocity and acceleration data are read by an Stm® development board embedded with an Stm32f401ccu6 microcontroller. The altitude of the measurement instrument platform was determined using an MS5611 barometric pressure sensor combined with a temperature sensor. The quadcopter’s control was achieved by connecting a brushless DC motor to the Stm® board, which received four PWM (pulse-width modulation) signals via the output port. An electronic governor was utilized to control the brushless DC motor, while a pre-existing remote control was designated as the transmitter. The quadcopter receiver received a 2.4 GHz signal from the transmitter using the BLE (Bluetooth low-energy) protocol, which was used to ensure the simultaneous operation of the four brushless DC motors. Finally, a PID (proportional–integral–derivative) controller was employed for parameter adjustment. The collected PID parameter program was developed in the Simulink software as a simulation platform, allowing for the execution of the Simulink model on the Stm® MCU. The Stm® module facilitates monitoring of the performance of the UAV (unmanned aerial vehicle) and enables immediate parameter adjustments to ensure flight stability. This research aims to reduce calculation errors in sensor and controller usage and improve the efficacy of the remote machine module for future industrial applications.

FPGA-based fault analysis for 7-level switched ladder multi-level inverter using decision tree algorithm

The proposed method involves the fault analysis of the inverter switches present in the multi-level inverter (MLI) circuitry. The decision tree machine learning algorithm is incorporated for the fault analysis of the inverter switches. The multi-level inverter utilized in this work is a 7-level switched ladder multi-level inverter. There is 4 number of switches in the design of a 7-level inverter driven by the non-carrier digital pulse width modulation signals. The non-carried-based digital pulse-width modulator (DPWM) generation is generated using the event angle for the 7-level of the switched ladder inverter. The proposed method investigates the stuck-at-fault occurrences of the 4 switches in the inverter by manipulating the decision tree parameters such as entropy, information gain, and decision tree. Based on the decision tree, the very high-speed integrated circuit hardware description language (VHDL) code is developed by making use of the behavioral modeling and validated for the power, area in the Xilinx Vivado tool. The real-time feasibility is verified for the proposed method by synthesizing the developed VHDL code in the field programmable gate array (FPGA) device.

Power Management Systems for Harmonic Elimination Using Hybrid Artificial Neural Networks Approaches

This study proposes two neural network-based approaches for computing the degrees required to generate pulse-width modulation (PWM) signals. The conventional method of using a lookup table to determine the orientations is replaced by these ANN models, which demonstrate superior performance across a range of modification indices. The first ANN is trained to estimate the phase angle based on input from the Empire Bird Optimizer, eliminating the need for a lookup table. A separate ANN is then trained using these configurations to generate the PWM signals. Experimental data on voltage level, inverter output current, and power flow are collected using a scope and power quality tester. The recommended hybrid ANN-based selective harmonic elimination PWM effectively removes low-order vibrations. The research is implemented in the MATLAB/Simulink platform, and the results indicate that the proposed system is efficient, accurately determining firing angles with minimal repetitions, and effectively addressing local minima values. The practical implementation of an eleven-level modular multilevel converter serves as the basis for this proposal, exemplified by an eleven-level H-bridge inverter.

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.

Dynamic resonance frequency control for a resonant-type smooth impact drive mechanism actuator

Multimodal piezoelectric actuators combine multiple vibration modes to achieve specific motions for precise actuation, or to enhance the output performance. For such a combination, the operating frequency ratio is necessarily an integer constraint. However, the resonance frequencies of target modes can be mismatched in assembly, and shift easily during operation, limiting the actuator applications. Therefore, we proposed a dynamic resonance frequency control method for multimodal piezoelectric actuators and applied it to a resonant-type smooth impact drive mechanism actuator. Passive piezoelectric parts were deployed on a Langevin transducer and connected with a field effect transistor (FET) switch. As a pulse width modulation (PWM) signal continuously adjusting the electrical boundary of these passive parts, the first longitudinal L1 mode’s resonance frequency was dynamically controlled to match the third L3 mode’s frequency with a ratio of two, generating a quasi-sawtooth displacement to drive a rotor. Experimental results indicated that the prototype’s L1 frequency can be continuously tuned from 25.715 to 24.76 kHz at 27 ℃, and the corresponding frequency ratio was adjusted from 1.953 to 2.028. Multimodal resonance frequency static matching was confirmed by changing the switching signal’s duty ratio. The L1 and L3 mode driving voltages were 50 Vp-p, and 23 Vp-p, respectively, and the speed of the rotor was 133.7 r/min. Dynamic resonance frequency control was realized with a feedback control system. As the driving PZT temperature increased to 70.5 ℃, both modes were matched and maintained resonance for 400 s. The results demonstrate that this method is conducive to improving actuator performance.

BLDC Motor Controller Design For Light Cars Aiming Safety Driving

This study investigates the Pulse Width Modulation (PWM) signal management techniques used in electric vehicles and how battery heat control is performed. It discusses how the application of the gas pedal, gear changes, and simultaneous pressing of gas-brake pedals prevent accidental movement of the vehicle in certain scenarios. Additionally, it evaluates the impact of battery management and heat control on the safety of the vehicle. The reviews and conclusions carried out have the potential to improve vehicle safety and battery life.

A Method of Ultra-Low Power Consumption Implementation for MEMS Gas Sensors

In recent years, there has been a growing need for the development of low-power gas sensors. This paper proposes pulse heating and a corresponding measurement strategy using a Pulse Width Modulation (PWM) signal to realize the ultra-low power consumption for metal oxide semiconductor (MOS) gas sensors. A Micro-Hot-Plate (MHP) substrate was chosen to investigate the temperature and power characteristics of the MHP under different applied heating methods. The temperature of this given substrate could respond to the applied voltage within 0.1 s, proving the prac ticability of a pulse heating strategy. In addition, Pd-doped SnO2 was synthesized as the sensing material in the implementation of an ultra-low power gas sensor. The sensing performance and power consumption under different conditions were compared in the detection of reducing gases such as ethanol (C2H5OH) and formaldehyde (HCHO). Additionally, the results revealed that the sensor could work under PWM excitation while reducing the operating power to less than 1mW. The features shown in the measurements provide the feasibility for MOS gas sensors’ application in wearable and portable devices.

A Family of Bidirectional Series Resonant Converter With Sine-Wave Modulation in Wide Voltage Range

A topology family of bidirectional series resonant converter with sine-wave modulation (SWM) is proposed in this article. The single-stage power transmission, zero voltage switching (ZVS) operation, and wide voltage regulation capacity can be realized of the proposed converters. On the basis of the traditional bidirectional series resonant converter, the proposed converters are generated by reconstructing the bridge arm without adding auxiliary switches or magnetic components. After reconstruction, the proposed converters combine the traditional pulsewidth modulation (PWM) circuit and the resonant circuit. Besides, a coupled inductor is used to replace the filter inductor, resonant inductor, and transformer, which reduces the magnetic components. In addition, under the proposed SWM, the voltage is adjusted by the duty cycle with fixed frequency, and the voltage gain is independent of the load. The driving logic of the primary and secondary side are completely consistent. Especially in the half bridge structures, only one set of complementary PWM signals are required. Furthermore, in wide voltage range, the resonant current is always a sine-wave, which can simplify the voltage gain and ZVS analysis. Finally, one of the proposed topologies is analyzed in detail, and a 500 W, 250 kHz experimental prototype with 100–200 V input and 150 V output was built. The experimental results proved the effectiveness and feasibility.

A Three-Phase Hybrid Multilevel Inverter With Enhanced Pulse-Width Modulation Strategy

This paper presents a three-phase hybrid multilevel inverter (MLI) with enhanced pulse-width modulation (PWM) strategy. The proposed hybrid MLI is developed based on the series connection of half-bridge and full-bridge for its level generation together with the T-type inverter for its polarity generation. The level and polarity generation circuits operate at high and fundamental frequencies respectively. An enhanced PWM strategy has been proposed to reduce the computational complexity and solve the high-frequency switching transitions issue in the existing hybrid MLI modulation method. The proposed MLI can produce 11 levels of line output voltage with reduced dc sources requirement. The detailed analyses which have been performed include the circuit configuration, operating principles and modeling, PWM signals generation, output voltage characteristics, dynamic response, harmonics content, power loss analysis and voltage stress of power switches. The results obtained from simulation and experiments verified the operating principle and functionality of the proposed hybrid MLI.

A monolithic gallium nitride‐based two‐phase synchronous buck converter with high operating frequency

AbstractThe need for a high‐frequency and high‐efficiency gallium nitride (GaN)‐based buck converter that can be controlled directly by a low swing pulse width‐modulated (PWM) signal, without the need for additional buffers or preamplifiers, poses a significant challenge in the field of power conversion and dynamically power supply applications. To solve this problem, this letter presents a monolithic two‐phase synchronous buck converter, fabricated using a 0.25‐um GaN‐on‐Si process, integrated both the drivers and power stage transistors, without requiring additional buffers or preamplifiers. So, the proposed converter can be directly controlled by a PWM signal with a swing of only 1 V (−0.5 to 0.5 V). At a 100‐MHz switching frequency, the converter achieves a maximum output power of 12 W with a power stage efficiency of 82%. The converter includes two identical half‐bridge Monolithic Microwave Integrated Circuit (MMICs), and with the frequency multiplication property of multi‐phase topology, the equivalent switching frequency can reach 200 MHz in the open‐loop operating mode. The experimental results show that the converter can track a 40‐MHz bandwidth envelope signal (256 QAM, 6 dB PAPR) with 80.1% efficiency.

A second‐order sliding mode control with active disturbance rejection for dynamic voltage restorers

AbstractThis paper proposes an extended state observer (ESO)‐based second‐order sliding mode control (SMC) for dynamic voltage restorers (DVRs). Unlike the conventional first‐order SMC and some second‐order SMC (SOSMC) methods that suffer from chattering, the proposed control method can alleviate chattering and achieve finite‐time convergence. Chattering suppression (i.e. eliminating discontinuities) is achieved via continuous control input which is also used to generate the pulse width modulation signals. However, while removing the discontinuities in the control input, the performance of the control method is degraded when it is subjected to disturbances. Therefore, an active disturbance rejection (ADR) based on an ESO is proposed to enhance the performance. In addition, an advanced single‐phase phase‐locked loop (PLL) using linear observer and quasi‐type‐1 PLL is also proposed. The effectiveness of the proposed method is verified through simulation and experimental results which are compared with the results of the existing SMC methods applied to DVR.

Wireless Piezoelectric Motor Drive

Nanopositioners with embedded piezoelectric motors are used in a variety of industries, from microscopy to laser processing or measurement systems. A concrete example would be fine-tuning of multiple mirror or lens units in a system. After fine adjustment of a mirror or lens, its position is expected to be maintained when the system is not energized. Features such as small size, direct drive, and maintaining position with high rigidity at power off make inertia-type piezoelectric motors suitable for such “set and go”-type applications. However, wiring with dedicated control electronics for each positioner can increase system complexity. In this study, a wireless driving method for piezoelectric inertia-type motors is introduced for the first time, to the best of our knowledge. In our approach, sawtooth signals for driving a two-phase piezoelectric inertia motor are converted into two complementary pulse-width-modulated (PWM) signals at 1.0 MHz and amplified by class-D amplifier topology, in which GaN transistors are implemented. The amplified complementary PWM signals are applied to a transmitter coil. A receiver coil, which forms an LC network with the capacitances of the piezoelectric multilayer actuators, picks up the driving signals. The filtered voltage waveform by the receiver coil is converted into a modified sawtooth signal, which can operate the piezoelectric inertia-type motor wirelessly. Initial measurements revealed that even a single driving pulse can be transmitted to the receiver coil and precise movements of the slider can be obtained. Mean step sizes for single pulse drive are 140 nm in one direction and 125 nm in the reverse direction.

Conditioning Circuits for Nanoscale Perpendicular Spin Transfer Torque Magnetic Tunnel Junctions as Magnetic Sensors

This article demonstrates a new type of magnetic sensor using a perpendicular spin transfer torque magnetic tunnel junction (MTJ). The sensing element has a cylindrical shape of 50 nm in diameter and is to our knowledge among the smallest magnetic sensor ever reported. This article describes the principle of operation of the sensing element and the associated signal processing electronics, which delivers a signal proportional to the external magnetic field. Experimental results are detailed and compared to the state-of-the-art commercially available integrated magnetic sensors as well as published magnetoresistive sensors based on MTJs with comparable size. The measured sensitivity of the developed sensor is 1.28 V/T, and its dynamic range reaches 80 mT. The measured noise level is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$21.8\,\mu \text{T}/\surd $ </tex-math></inline-formula> Hz. Two different operating principles of the proposed sensor are described and compared, one based on a time-to-digital converter and one based on a pulsewidth-modulated (PWM) signal. Both methods require only standard microelectronics components, which are suitable for monolithic integration of the sensing element with its conditioning electronics. Subsequent improvements of the sensing element as well as conditioning electronics are required to further lower the noise level. The sensing element and its conditioning electronics are compatible with fabrication processes already used in magnetic random access memory fabrication. This opens the way to mass production and addresses various markets, such as consumer electronics, automotive, industrial sensing, physics experiments, or medical devices.

Study of characteristics of PWM signals in electromagnetic vibration drive control systems

The paper studies three forms of the pulse-width modulated (PWM) signal which is used to power the electromagnetic vibration drives of resonance-type vibrating machines. On the basis of a comparative analysis of the characteristics of PWM signals using the root mean square deviation for the time domain, the nonlinear harmonics (distortions) coefficient for the spectral domain, and the structure of the power part of the switches that form these signals, conclusions have been drawn on the feasibility of using different types of PWM in the control systems of electromagnetic vibratory drives.

Experimental Investigation of State and Parameter Estimation within Reconfigurable Battery Systems

The battery system is one of the most-important, but also -critical components in the electric power-train. The battery’s system states and parameters are commonly tracked by the battery monitoring system. However, in reality, the accuracy of the state and parameter estimation may suffer from insufficient excitation of the system. Since the current states and parameters serve as the basis for many battery management system functions, this might lead to incorrect operation and severe damage. Reconfigurable battery systems allow enhancing the system’s excitation by applying a switching operation. In this contribution, the state and parameter estimation of a reconfigurable battery module were simulated and tested experimentally. Thereby, a low-exciting and a high-exciting drive cycle were compared. Furthermore, the switching patterns were applied to enhance the excitation and, hence, improve the estimation of an extended Kalman filter. The cells were switched via a pulse-width modulation signal, and the influence of frequency and duty cycle variation on the estimation accuracy were investigated. Compared to the low-excitation input, a significant improvement in the estimation of up to 46% for the state of charge and 78% for the internal resistance were achieved. Hereby, low frequencies and duty cycles proved to be particularly advantageous. Switching, however, has only a limited influence on an already highly excited system and may lead to additional aging due to higher heat generation.

Design and implementation of a driver circuit for three-phase induction motor based on STM32F103C8T6

A three-phase induction motor is an electrical machine that can be used for many industrial applications. A three-phase driver circuit, also known as a three-wire series circuit or three-wire delta circuit is an electrical power system. These motors typically rely on power supplied using electric cables, which carry alternating currents. The three-phase motor inverter driver circuit is a simple circuit consisting of three half-wave rectifiers, which are connected in a bridge. When the input voltage level of the DC power supply to the inverter is high enough, this arrangement can provide a large current through the induction motor. This paper will show how to build a three-phase inverter driver circuit from scratch for a threephase induction motor by using (transistors and diodes) for photovoltaic application. The paper will guide people through each step with diagrams and schematics that make it easy for anyone to understand every part of this project and ensure people's safety by learning how these components work before putting them into their own design. The focus of this project will be on the use of STM32F103C8T6 as microcontrollers to generate the pulse width modulation (PWM) signals.

A Distortion-Free All-Digital Transmitter Based on Noise-Shaped PWM

A novel pulse-width modulation (PWM) architecture for all-digital transmitters (ADT) that achieves good in-band and out-band performance with a very low ratio between the modulated signal frequency and the carrier frequency is presented in this paper. The proposed scheme reduces the harmonics leaving only those corresponding to multiples of the carrier frequency, overcoming the spectral limitations of other PWM implementations and relaxing the filter requirements. The binary signal is obtained using a table-based approach with very low computational complexity, mapping the complex I/Q baseband signal to duty cycles of a square wave with low distortion. In addition, a new parallelized noise shaping circuit to reduce the distortion caused by the discretization of the duty-time intervals is presented. The digital radio frequency signal is generated using a high-speed serializer and a standard pulse former. The ADT is simulated under different scenarios to evaluate the influence of time resolution in terms of Adjacent Channel Power Ratio (ACPR) and Error Vector Magnitude (EVM). The transmitter performance is verified by an FPGA implementation using 64-QAM modulated signals, achieving values of ACPR1, ACPR2, and EVM better than −47 dBc, −53 dBc, and −35 dB, respectively, using 64 quantization levels for the PWM signal.