Pulse Width Modulation Inverter Research Articles

Continuous Control Set Model Predictive Current Control of a Microgrid-Connected PWM Inverter

This paper deals with a novel control architecture for pulse width modulation inverters connected to the grid through resonant LCL filters. A continuous-control-set model predictive control scheme is derived for the grid current loop. A state observer, using a moving horizon estimator algorithm, is used for reducing the order of the mathematical model representing the grid. The proposed control architecture allows for reducing the number of required sensors, for eliminating measurement noise and for achieving a good stability against voltage grid disturbances and parameter uncertainties. High performance hardware is used in order to run a quadratic programming solver in real-time, with a control sampling rate of 10 kHz. The effectiveness of the proposed control architecture is validated by means of test-bed experiments demonstrating the feasibility of real-time operation and promising results.

Saliency-Based Permanent Magnet Machine Position Sensorless Drive Using Proposed PWM Injection and Shunt-Based Current Sensing for Position Estimation

For saliency-based position sensorless drives, the switching frequency pulsewidth modulation (PWM) voltage injection can achieve noise-free position estimation which is suited for high-performance motion systems. However, considering the switching frequency injection, multiple phase currents should be sampled per PWM cycle instead of single average current. It leads to the implementation issue on the space-vector PWM (SVPWM) inverter using shunt resistor current sensing for machine control. In this article, a modified PWM injection instead of SVPWM injection is proposed for the saliency-based drive using shunt current sensing. It is concluded that at least two transient currents can be sampled per PWM cycle based on the proposed PWM control. More importantly, the field-oriented control is maintained when the saliency-based drive is applied. A 2 kW permanent magnet (PM) machine is used for the experimental verification. This article includes the position estimation comparison using either the proposed PWM injection with shunt resistors or standard SVPWM with Hall-effect sensors.

Design and simulation hybrid filter for 17 level multilevel inverter

The increasing of renewable energy applications such as solar cells, wind power, ocean thermal and HVDC (high voltage direct current) cause increment in the use of the inverter circuit. Harmonics that are generated by the inverter have negative impacts on the electrical equipment; harmonics cause excessive heat and may shorten the life of electrical equipment. A multilevel inverter is an arranged of cascaded inverters which aims to reduce total harmonic distortion (THD). This paper proposes the design of 17 levels of a single-phase cascaded multilevel inverter with a hybrid filter insertion. By using PSIM simulator, the hybrid filter is proven reducing THD better than single pulse width modulation (SPWM) inverter. Installation of the hybrid filter is able to fix a maximum of 0.23% THDv and a maximum of 1.05% THDi. Hybrid filter installation reduces the value of THD to comply with IEEE 519-2014 standard.

An Online Data-Driven Method for Simultaneous Diagnosis of IGBT and Current Sensor Fault of Three-Phase PWM Inverter in Induction Motor Drives

This article presents an online data-driven diagnosis method for multiple insulated gate bipolar transistors (IGBTs) open-circuit faults and current sensor faults in the three-phase pulsewidth modulation inverter. The fast Fourier transform (FFT) algorithm is used to extract the fault frequency spectrum features of the three-phase currents. Then, a feature selection method named ReliefF is introduced to select the most critical features by removing redundant and irrelevant features. In addition, as novel fast learning technology, a random vector functional link network is applied to learn the faulty knowledge from the historical dataset. Based on the well-learned model, the fault type and location of the converter can be accurately identified as long as the three-phase current signals are measured. Offline test results verify that the proposed method can identify the IGBT and sensor faults with an accuracy of 98.83% and outperforms the state-of-the-art learning algorithms. Moreover, the real-time hardware-in-the-loop test results show that the proposed method can successfully identify the IGBT faults and current sensor faults within 22 ms. It is robust to the dc-link voltage fluctuations, model parameters, and speed or load variations. The extensibility of the proposed method is also validated based on the test results in terms of other fault modes and drive systems.

Analytical current THD evaluation for three‐phase voltage source inverters

This study addresses the calculation of current total harmonic distortion (THD) for three-phase (3P) pulse-width modulation (PWM) inverters. First, it demonstrates how an analytical approach to PWM current ripple normalised mean square (NMS) calculation introduced in the late 1980s for a two-level (2L) inverter can be used for current THD evaluation. Second, it is shown how to evaluate current THD for a three-level (3L) 3P inverter using the current ripple NMS concept. Though considered is a 3P cascaded inverter with one H-bridge per phase, the results are applicable to popular 3L neutral point clamped (T-type) and flying capacitor inverters.

Comparison of the Wideband Power Sources Used to Supply Step-Up Current Transformers for Generation of Distorted Currents

In this paper a comparison of the wideband power sources of a pulse width modulation (PWM) inverter and a power supply composed of an audio power amplifier and a two-channel arbitrary generator is discussed. Their application is to supply a step-up current transformer for generation of the distorted current required to test the transformation accuracy of the distorted currents of the inductive current transformers. The proposed equations allow to calculate the maximum rms values of higher harmonic of distorted currents for its required main harmonic component. Moreover, they also enable the calculation of the maximum rms values of the main harmonic of the distorted current for which the required higher harmonic component may be obtained. This defines the usable bandwidth of the tested power source for their specific load. During work on high inductive impedance, the maximum voltage is the limitation that determines the higher harmonic value. While for resistive loads, the maximum current and the transistor’s slew rate are the limiting factors. The usage of the compensation system for the inductive reactance of the step-up current transformer under supply significantly increased its maximum output current. Its rms value with a 10% higher harmonic component up to 5 kHz was almost 400 A instead 100 A for the PWM-based power source and about 800 A instead 200 A for the power supply system with the audio amplifier.

Magnifying Steadiness & Conducting Examination of PMSM with SVPWM and PI Controller

A new method to improve the strength of permanent magnet synchronous machine (PMSM) is proposed in this manuscript. It utilizes the principal of space vector pulse width modulation (SVPWM) & proportional integral control (PI). The SVPWM allows the motor to have a high voltage with low harmonic distortion than the typical sinusoidal pulse width modulation. The control technique which is used in this paper is the voltage-frequency control process which depends on space vector pulse width modulation. The triggering pulses of space vector pulse width modulation inverter which is been given to the motor enables the motor to have a bigger torque at high speeds & elevated efficiency. It also increases the use of DC link voltage & low output harmonic distortion than the typical sine pulse width modulation inverter. The suggested permanent magnet synchronous machine module that involves a field-oriented control method not only links torque & flux, but also facilitates control allocation. Finally investigation of the suggested model is examined and its results are been validated by the simulation.

Design, Analysis, and Impacts of Sinusoidal LC Filter on Pulsewidth Modulated Inverter Fed-Induction Motor Drive

Squirrel-cage induction motor (SQIM) fed by a pulsewidth modulated voltage source inverter (VSI) is subjected to voltage and current surges. It may cause additional losses in the motor, insulation failure, high bearing current, and electromagnetic interference. To mitigate these problems, sinusoidal LC filter is placed at the ac-side of the VSI. This paper proposes a new methodology to design the filter. In this method, the filter inductance is chosen based on the maximum ripple in the inverter ac-side current and the voltage drop across the filter inductor, and the filter capacitor is chosen based on the steady-state reactive power demand of the SQIM. The effects of the designed filter on the switch current, losses in the drive, temperature of the dc-link capacitor, dv/dt at the motor terminal, stator flux, and air-gap torque of the SQIM are discussed. The performance of the drive with the filters, designed by the proposed method and the standard method, are experimentally tested on a two-level silicon carbide VSI-fed SQIM and comparative analysis is carried out. The impact of the designed filter on the drive is also shown when the neutral point of the filter capacitors is connected with the mid-point of the dc link. The stability of the closed-loop controlled SQIM drive with the proposed filter, and simulation results are presented to verify its performance.

Implementation of dead beat controller using Particle Swarm Optimization for software defined network

Renewable energy sources is largely adopted for generation of electrical energy and various methodologies have been proposed in this area This paper focuses on analysis, design and implementation of DC/DC buck–boost converter towards producing the hybrid prototype, consisting of 3kW PV and 3.2 kW PMSG using wind energy conversion system. Particle Swarm Optimization algorithm is employed for regulation of the output voltage generated. To extract maximum power, PSO algorithm is adopted for hybrid renewable energy sources which are considered as NP hard problem. To eliminate the harmonics and to have maximum electrical power delivered to the grid on polynomial time, the single phase or three phase sinusoidal pulse width modulation (SPWM) inverter has been employed with PQ control strategy using metaheuristic based approximation. The proposed PSO technique produces a steady state DC link voltage of 400 V with reduced harmonic distortion using LC filter. Further, the application of capacitor bank arrangement reduces the ripples present in the output voltage variations. The simulation outcomes prove the efficiency of the proposed model along its measurements.

DC‐link voltage control strategy of Z‐source inverter for high‐speed permanent magnet motor

In order to widen the flux-weakening range of motors, this study proposed a DC-link voltage control strategy for high-speed permanent magnet motor drive systems powered by Z-source inverter. In this strategy, the DC-link voltage, also known as the output voltage of the impedance network, varies with the inverter output voltage and remains optimal at all times, whether in steady state or transient state. As for the shoot-through duty ratio and the modulation index, the two main control variables in the Z-source inverter are under unified control to ensure the stability of the system, while achieving fast tracking and reducing the loss. In addition, a new sliding mode control system based on the indirect control of the capacitor voltage is used to control the DC-link voltage to suppress the system fluctuation caused by the change of the given value or the motor load. Besides, various conventional voltage Z-source inverter pulse width modulation strategies can be applied to this technology. Simulations and experiments verified the effectiveness of the proposed strategy.

Precise Electrohydrodynamic Direct-Write Micro-Droplets Based on a Designed Sinusoidal High-Voltage AC Power

The precise manufacturing of micro/nano structures is the key to the rapid development of flexible micro/nano systems. In this paper, a sinusoidal high-voltage alternating current (AC) power is designed for electrohydrodynamic direct-writing (EDW) technology. A push-pull converting circuit is utilized as the direct current (DC) voltage regulator power of a full-bridge inverter circuit. A single-phase full-bridge inverter circuit is used to output the controllable AC voltage, which is then boost-filtered to output the high-voltage sinusoidal AC signal. The amplitude of the output sinusoidal voltage is proportional to the input voltage and the modulation degree of the sinusoidal pulse width modulation (SPWM) inverter circuit. Then, the designed sinusoidal high-voltage AC power is used in the AC EDW process to print micro-droplets. The deposition frequency and the average diameter of droplets can be effectively controlled by adjusting the voltage amplitude and the voltage frequency. The design of this sinusoidal high-voltage AC power will promote research on the applications of EDW technology in the field of micro/nano manufacturing.

High‐performance speed estimation of induction machines based on adaptive filtering

This paper presents a novel algorithm for sensorless detection of the rotor speed applied to induction machines, which relies on rotor slot harmonics (RSHs). The estimator structure is proposed, for extracting and tracking the RSH found in the stator line current, which offers improved results compared with previously published methods. The proposed method reduces delays, output jitter, and steady-state error. A stability analysis is provided and used in the design procedure to ensure system reliability. The capability of using the estimated signal as speed feedback in a sensorless drive is tested and confirmed. The system employs a bandpass filter with a centre frequency that is adapted according to the estimated speed, a high bandwidth phase-locked loop, and an observer. Tracking limits and parameter design are explained analytically; the method is verified in simulations and confirmed experimentally. Experimental verification is performed on a standard three-phase induction motor, using a three-phase pulse-width modulation inverter.

Optimal time-domain pulse width modulation for three-phase inverters

An optimal time-domain technique for pulse-width modulation (PWM) in three-phase inverters is presented. This technique is based on the time-domain per phase analysis of three-phase inverters for linear, balanced output load circuits. Exact analytical solutions for the output phase currents are presented for first, second, and third order circuits for any sequence of rectangular pulses. Next, the role of symmetries in the structure of three-phase PWM inverter voltages is discussed. Finally, using the exact analytical solutions for phase-currents as well as symmetry considerations, minimization of output current harmonics is set up as an optimization problem. Sample numerical results are presented that highlight improvements in the performance of three-phase inverters.

Ground Leakage Current Caused by Common-Mode Voltage of PWM inverter

In railway tractive vehicles, three-phase PWM (Pulse Width Modulation) inverters generate parasitic Differential-Mode Voltages (DMV) and Common-Mode Voltages (CMV). Parasitic voltages are a side effect of using the width modulation to shape the phase-to-phase inverter’s voltage. In this article, the authors present a mathematical description of the DM and CM voltages and carry out their spectral analysis. Based on the spectral harmonics analysis, the authors present a method for filtration of harmonics of DM and CM voltages aimed at limiting the capacitance parasitic currents: due to DM voltage – phase-to-phase parasitic current and CM voltage – ground parasitic currents. As the final result of the tests, almost complete elimination of leakage parasitic current form PE shock protection system was achieved.

INVERTER PWM UNTUK MENGGERAKKAN MESIN ARUS SEARAH TANPA SIKAT BERBASIS ARDUINO

This study aims to create a PWM inverter that can drive the Brushless Unidirectional Flow Machine (MASTS). PWM inverters are intended to correct deficiencies in six-step inverters. Inverter is a circuit that is used to convert a DC voltage source into an AC voltage with a certain frequency. The use of inverters is found in electric vehicles. The system often used to control an inverter is a Pulse Width Modulation (PWM) based control, where pulse width is used to regulate speed. The inverter is tested using 3 pairs of mosfets as a switch to control the three-phase output of the inverter. In the inverter, PWM is used to adjust the width of the frequency pulse that will be given to the mosfet. This research used 3 variations of duty cycle 30%, 60%, 90% to determine the effect of MASTS speed on PWM by using a PWM inverter. The results of this study the speed of MASTS can be influenced by changes in duty cycle, with increasing value of the duty cycle, the faster the speed of MASTS, and vice versa. Keywords:Mosfet, Sensor Hall, MASTS, PWM, Inverter.

An improved selective harmonics elimination technique for PV assisted single phase grid-tied PWM inverter

Purpose The purpose of this study is to present a new methodology of selective harmonics elimination (SHE) technique suitable for single-phase photovoltaic (PV) tied pulse width modulated (PWM) inverter. Design/methodology/approach In the proposed SHE, switching angles for inverter control are determined offline through numerical techniques and stored in a microcontroller memory as a function of modulation index (md). The methodology uses the solution that leads to a lower change of switching angles from the previous modulation index (md) for storing in the processor memory for multiple solutions. This leads to a smaller number of sections when a piecewise mixed model is considered for storing the entire switching angle curve for the online inverter control. The proposed idea is simulated and experimentally validated on a laboratory prototype of PV (500 W) grid-tied PWM inverter. The control environment is then realized in NI c-RIO 9082. Findings This proposed technique is suitable for limiting voltage total harmonics distortion (THD) in single-phase PV tied grid connected voltage source inverter (VSI). Moreover, it is found that filter (L-C) size requirement is less. Originality/value The proposed SHE with piecewise mixed model technique effectively reduces voltage THD with less filter size (L-C) in a single-phase PV-tied system.

Single-Phase Inverter Deadbeat Control with One-Carrier-Period Lag

This paper presents a novel digital control scheme for the regulation of single-phase voltage source pulse width modulation (PWM) inverters used in AC power sources. The proposed scheme adopts two deadbeat controllers to regulate the inner current loop and the outer voltage loop of the PWM inverter. For the overhead of digital processing, the change of duty of PWM lags one carrier period behind the sampling signal, which is modeled as a first-order lag unit in a discrete domain. Based on this precise modeling, the deadbeat controllers make the inverter get a fast dynamic response, so that the inverter’s output voltage is obtained with a very low total harmonic distortion (THD), even when the load is fluctuating. The parameter sensitivity of the deadbeat control was analyzed, which shows that the proposed deadbeat control system can operate stably when the LC filter’s parameters vary within the range allowed. The experimental results of a 2kW inverter prototype show that the THD of the output voltage is less than 3% under resistive and rectifier loads, which verifies the feasibility of the proposed scheme. An additional advantage of the proposed scheme is that the parameter design of the controller can be fully programmed without the experience of a designer.

A novel sensorless current shaping control approach for SVPWM inverter with voltage disturbance rejection in a dc grid–based wind power generation system

AbstractA novel sensorless current shaping (CS) control strategy is proposed to avail better power quality (PQ) of a dc grid–based wind power generation system (WPGS) used on a poultry farm by generating an appropriate reference current for space vector pulse width modulation (SVPWM) inverter. The proposed CS strategy also offers adequate control for parallel operation of multiple generators and inverter applications, without requiring voltage and frequency synchronization. Further, to control the poultry farm–based WPGS, a two‐stage control loop is implemented such as energy flow control loop (EFCL) and harmonic control loop (HCL). The first loop is used to regulate the power flow, and the second loop is used to compensate harmonics. A mathematical current decomposition technique is suggested for an appropriate resistance emulation to realize a better power flow, higher harmonic rejection, and better inverter operation. In this planned approach for attaining constant wind speed, an electric ventilation fan in the poultry farm is used. A combined hybrid dc and ac grid approaches are suggested for facilitating variable load integration in a poultry farm–based microgrid system. Moreover, for achieving better power management during the islanded mode of operation, the battery energy storage (BES) device is integrated with the dc grid through a bidirectional converter. The proposed WPGS design and control approach has been simulated through MATLAB/Simulink software under various test conditions, to demonstrate the operational capability, to achieve better PQ, and to increase the flexibility and reliability in the microgrid operation.

Adoption of Multilevel Inverter based Dynamic Voltage Restorer for Power Quality Improvement with Adjustable DC-Link

Dynamic Voltage Restorer (DVR) is a method of overcoming voltage sag and swell in electrical power distribution. To boost up voltage levels on load side on power disturbances DVR can be used so as the equipment connected will have good voltage profile In this Pulse Width Modulation inverter is in solid-state electronic switching device were employed along with Integrated Gate Bipolar Transistor by the DVR, the alternating current voltage is controllable at real and reactive powers which are made independently. The MLI; is organized as the cascaded H-bridge inverter units. The function of Multilevel Inverter; is to arrange the voltages from a significant direct current source. Here in the DVR, there is no need for external output filters. In the planned DVR, a dc-dc converter is combined with an MLI. By considering the voltage sag magnitude of a dc-dc converter can regulate the dc-link voltage. Hence the output voltage of the multilevel inverter; always has a last number of levels. Instead of using the PWM based technique, the fundamental frequency method can be used in the multilevel inverter. The proposed DVR operation range of mathematical analysis is specified in detail. The simulation results are prepared by using Simulink/MATLAB.

A Passive Soft-Switching Snubber With Energy Active Recovery Circuit for PWM Inverters

A passive soft-switching snubber with energy active recovery circuit (PSS-EARC) for pulse width modulation (PWM) inverters is proposed in this paper. The PSS-EARC recovers the buffering energy of the snubber inductors and capacitors back to the input voltage source while achieving passive soft-switching, so as to improve the inverter efficiency. In this paper, the configuration and operation principle of the PSS-EARC are analyzed and studied in detail firstly. Comparing with the traditional energy passive recovery circuit, the PSS-EARC avoids the circulating current issue by employing the auxiliary switches. Because the control of auxiliary switches is simple and independent, it is also benefit to the integration of auxiliary circuits. Moreover, in three-phase inverter application, the EARC is shared by three bridge-legs, which may further simplify the circuit. Finally, a 10kW three-phase inverter with the PSS-EARC is built. The experimental results demonstrate the validity and superiority of the proposed circuit.