scholarly journals A Novel Current Injection Circuit for Adjustable Speed Drives

2019 ◽  
Vol 8 (4) ◽  
pp. 3933-3935
Keyword(s):  
High Efficiency ◽  
Harmonic Distortion ◽  
Current Injection ◽  
Duty Ratio ◽  
Switching Frequency ◽  
Current Harmonics ◽  
Active Devices ◽  
Adjustable Speed Drive ◽  
Adjustable Speed ◽  
Voltage Harmonics

An adjustable speed drive creates the harmonics. The novel current injection circuit does not need any additional active devices. With the significant reduction in current harmonics, the AC input line current is sinusoidal. The ZVS technique is used for all the switches operation. The rectifier diodes are by soft switching. The output voltage regulated by fixed duty ratio with varying switching frequency. The advantages of proposed AC-DC-AC systems are low price, compact, high efficiency, and simplicity. Nine level diode clamped inverter produces the voltage harmonics of 8.75%. The Total Harmonic Distortion (THD) of input current is as low as 7.72 % and power factor as high as 0.99. Theoretical results are verified initially through PSIM simulation and validated with an experimental prototype of 2.5Kw.

Design and Implementation of Z-Source Inverter by Simple Boost Control Technique for Laboratory Scale Micro-Hydro Power Plant Application

2021 ◽  
Vol 13 (2) ◽  
pp. 62-70
Author(s):  
Rizki Mendung Ariefianto ◽  
Rizky Ajie Aprilianto ◽  
Heri Suryoatmojo ◽  
Suwito Suwito
Keyword(s):  
Power Plant ◽  
High Efficiency ◽  
Electrical Power ◽  
Harmonic Distortion ◽  
Laboratory Scale ◽  
Control Technique ◽  
Induction Generator ◽  
Duty Ratio ◽  
Hydro Power ◽  
Boost Control

In a power plant such as micro-hydropower (MHP), an induction generator (IG) is usually employed to produce electrical power. Therefore, an inverter is needed to deliver it with high efficiency. Z-source inverter (ZSI) has been introduced as a topology with many advantages over conventional inverters. This research aims to investigate the performance of ZSI based simple boost control (SBC) in laboratory-scale MHP systems using a rewinding induction generator. This research has been conducted both from simulations and experiments. Based on the result, the waveform characteristic and value of ZSI are close to the desired design. A shoot-through duty ratio of 17% can reach 60 Vrms output voltage, and this condition has a conversion ratio of about 2.05 times. Also, SBC can significantly reduce the Total Harmonic Distortion (THD). ZSI efficiency has a value of 84.78% at 50% of rating load 100 W and an average value of 80%. Compared to the previous study, the proposed design has more economical with the same component for the higher rating power. Moreover, it has a smoother and entire output waveform of the voltage.

scholarly journals Power Factor Corrector Based on Parallel Quasi- Resonant Pulse Converter with Fast Current Loop

2013 ◽  
Vol 3 (1) ◽  
pp. 5-11 ◽  
Author(s):  
Yuriy Denisov ◽  
Serhii Stepenko
Keyword(s):  
Power Factor ◽  
High Efficiency ◽  
Harmonic Distortion ◽  
Input Voltage ◽  
Current Loop ◽  
Switching Frequency ◽  
Zero Current Switching ◽  
High Switching Frequency ◽  
Power Factor Corrector ◽  
Pulse Converter

Abstract The problems, devoted to power quality and particularly power factor correction, are of great importance nowadays. The key requirements, which should be satisfied according to the energy efficiency paradigm, are not limited only by high quality of the output voltage (low total harmonic distortion), but also assume minimal power losses (high efficiency) in the power factor corrector (PFC). It could be satisfied by the use of quasi-resonant pulse converter (QRPC) due to its high efficiency at high switching frequency instead of the classical pulse-width modulated (PWM) boost converter. A dynamic model of QRPC with zero current switching (ZCS) is proposed. This model takes into account the main features of QRPC-ZCS as a link of a PFC closed-loop system (discreteness, sharp changes of parameters over switching period, input voltage impact on the gain). The synthesized model is also valid for conventional parallel pulse converter over an active interval of commutation. The regulator for current loop of PFC was synthesized based on digital filter using proposed model by the criterion of fast acting.

scholarly journals Investigation and Experimental Validation of Sideband Harmonic Vibration of IPMSM with and without Skewed Slots for EVs

2021 ◽  
Vol 12 (4) ◽  
pp. 223
Author(s):  
Zhenkang Feng ◽  
Daohan Wang ◽  
Chen Peng ◽  
Wentao Feng ◽  
Bingdong Wang ◽  
...  
Keyword(s):  
Pulse Width Modulation ◽  
High Efficiency ◽  
Torque Ripple ◽  
Synchronous Machines ◽  
Switching Frequency ◽  
Permanent Magnet Synchronous Machines ◽  
Steady State Operation ◽  
Voltage Harmonics ◽  
The Magnetic Field ◽  
Vector Control Strategy

Due to their advantages of high power density and high efficiency, permanent magnet synchronous machines (PMSMs) are widely used in the field of electric vehicles (EVs). Vibration and noise are important indicators for evaluating the performance of PMSMs, and the skewed slot method is now widely used to mitigate the torque ripple and noise of motors. In the vector control strategy, the space vector pulse width modulation (SVPWM) method produces sideband voltage harmonics with a frequency near the switching frequency. These harmonics act on the magnetic field to generate an excitation force with a frequency near the switching frequency. This paper compares and analyzes the sideband harmonic current and the exciting force of a skewed slot motor and a straight slot motor during steady-state operation. The research results show that the skewed slot method can effectively mitigate the vibration and noise caused by sideband harmonics.

scholarly journals An Impedance Source Multi-Level Three Phase Inverter with Common Mode Voltage Elimination and Dead Time Compensation

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1639
Author(s):  
Mehrdad Mahmoudian ◽  
Maziyar Fakhraei ◽  
Edris Pouresmaeil ◽  
Eduardo M. G. Rodrigues
Keyword(s):  
High Efficiency ◽  
Dead Time ◽  
Harmonic Distortion ◽  
Common Mode ◽  
Current Harmonics ◽  
Pulse Width Modulated ◽  
Switching Algorithm ◽  
Common Mode Voltage ◽  
Power Switches ◽  
Drive Systems

Currently, most electro-mechanical drive systems that require speed control use pulse-width modulated (PWM) variable frequency drives known as adjustable speed drives (ASD). The high switching speeds of the electronics switches are essential for proper operation of the ASD. Common mode voltage (CMV) has its origin in the PWM switching. The CMV increases the stress on the coils and windings, reduces the life of the bearing and, therefore, has a significant impact on motor life cycle. In this paper, a variant of a PWM-based space vector modulation (SVPWM) switching algorithm is proposed to control both the shoot-through intervals and the dead time of the power switches that could be compensated. The proposed algorithm is implemented on a platform consisting of an impedance source network in the DC side of the topology with the purpose of mitigating the CMV and capability of voltage boosting. Since similar methods have achieved a CMV reduction of 1/6 of the DC link voltage so far, in this paper, while surpassing the disturbing current harmonics, the high efficiency is fully accessible. The presented experimental results verify the effectiveness of the proposed approach by slightly increasing the total harmonic distortion (THD) and reducing the converter losses.

A Tactical Chaos based PWM Technique for Distortion Restraint and Power Spectrum Shaping in Induction Motor Drives

2015 ◽  
Vol 5 (3) ◽  
pp. 383 ◽  
Author(s):  
V. Mohan ◽  
N. Stalin ◽  
S. Jeevananthan
Keyword(s):  
Induction Motor ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Harmonic Distortion ◽  
Torque Ripple ◽  
Motor Drives ◽  
Voltage Source ◽  
Switching Frequency ◽  
Induction Motor Drives ◽  
Current Harmonics

The pulse width modulated voltage source inverters (PWM-VSI) dominate in the modern industrial environment. The conventional PWM methods are designed to have higher fundamental voltage, easy filtering and reduced total harmonic distortion (THD). There are number of clustered harmonics around the multiples of switching frequency in the output of conventional sinusoidal pulse width modulation (SPWM) and space vector pulse width modulation (SVPWM) inverters. This is due to their fixed switching frequency while the variable switching frequency makes the filtering very complex. Random carrier PWM (RCPWM) methods are the host of PWM methods, which use randomized carrier frequency and result in a harmonic profile with well distributed harmonic power (no harmonic possesses significant magnitude and hence no filtering is required). This paper proposes a chaos-based PWM (CPWM) strategy, which utilizes a chaotically changing switching frequency to spread the harmonics continuously to a wideband and to reduce the peak harmonics to a great extent. This can be an effective way to suppress the current harmonics and torque ripple in induction motor drives. The proposed CPWM scheme is simulated using MATLAB / SIMULINK software and implemented in three phase voltage source inverter (VSI) using field programmable gate array (FPGA).

scholarly journals A Phase-Shift-Modulated LLC-Resonant Micro-Inverter Based on Fixed Frequency Predictive-MPPT

Energies ◽  
2020 ◽  
Vol 13 (6) ◽  
pp. 1460
Author(s):  
Omar Abdel-Rahim ◽  
Nehmedo Alamir ◽  
Mohamed Abdelrahem ◽  
Mohamed Orabi ◽  
Ralph Kennel ◽  
...  
Keyword(s):  
High Efficiency ◽  
Harmonic Distortion ◽  
Maximum Power ◽  
Switching Frequency ◽  
Resonant Converter ◽  
Fixed Frequency ◽  
Pv System ◽  
Partial Shading ◽  
Llc Resonant Converter ◽  
Micro Inverter

Maximum Power Point Tracking (MPPT) control is an essential part of every photovoltaic (PV) system, in order to overcome any change in ambient environmental conditions and ensure operation at maximum power.. Recently, micro-inverters have gained a lot of attention due to their ability to track the true MPP for each individual PV module, which is considered a powerful solution to overcome the partial shading and power mismatch problems which exist in series-connected panels. Although the LLC resonant converter has high efficiency and high boosting ability, traditional MPPT techniques based on Pulse Width Modulation (PWM) do not work well with it. In this paper, a fixed frequency predictive MPPT technique is presented for the LLC resonant converter to be used as the first-stage in a PV micro-inverter. Using predictive control enhances the tracking efficiency and reduces the steady state oscillation. Operation with fixed switching frequency for the LLC resonant converter improves the total harmonic distortion profile of the system and ease the selection of circuit magnetic component. To demonstrate the effectiveness of the proposed MPPT technique, the system is simulated using MATLAB/Simulink platform. Furthermore, a 150 W hardware prototype is developed and tested. Both simulation and experimental results are consistent and validate the proper operation of the developed system.

scholarly journals ANALISIS KUALITAS DAYA PADA SUPLAI DAYA LISTRIK PT. SOSRO

2020 ◽  
Vol 1 (1) ◽  
pp. 27-33
Author(s):  
Aceng Daud Energi
Keyword(s):  
Power Systems ◽  
Harmonic Distortion ◽  
Data Logger ◽  
Current Harmonics ◽  
Ac Power ◽  
Linear Load ◽  
Harmonic Components ◽  
Non Linear Load ◽  
Voltage Harmonics

In more than ten years, quality of electricity has growed from clearness to be an principal issue. One heavy problems from quality of power is harmonic distortion and its consequences. Particularly, the increasing of penetration of loads bases on power electronics (non-linear load) what creates a harmonic distortion in AC power systems. Then, quality of electricity becomes principal issue for utility and its consumer and both swiftly adopts philosophy and proposes limits in new international standard (IEC, EN, BS, IEEE). As consequence the equipments of power conditioning (converter) will become more important for electrical utility and its consumer. From the results with the data logger recording at PT SOSRO distribution feeder system found that there are several current and voltage harmonics are significant in the load and hence the supply side. Fifth and the seventh Harmonic are heaviest harmonic components in the current load. Installation of passive filters will be one solution to overcome the issue with the current harmonics. The recomendation proposed will be submitted to management for consideration PT SOSRO factory in determining which type of passive filter will be used.

Dependence of Current Harmonics of Greenhouse Irradiators on Supply Voltage

2020 ◽  
pp. 85-88 ◽  
Author(s):  
Nadezhda P. Kondratieva
Keyword(s):  
Mathematical Models ◽  
Supply Voltage ◽  
Harmonic Distortion ◽  
Feasibility Studies ◽  
Power Losses ◽  
Voltage Level ◽  
Supply Networks ◽  
Current Harmonics ◽  
Cable Lines ◽  
Harmonic Composition

The article describes the results of the study concerning the effect of the voltage level on current harmonic composition in greenhouses irradiators. It is found that its change affects the level of current harmonics of all types of the studied greenhouse irradiators. With decrease of nominal supply voltage by 10 %, the total harmonic distortion THDi decreases by 9 % for emitters equipped with high pressure sodium lamps (HPSL), by 10 % for emitters with electrode-less lamps and by 3 % for LED based emitters. With increase of nominal supply voltage by 10 %, THDi increases by 23 % for lighting devices equipped with HPSL, by 10 % for irradiators with electrode-less lamps and by 3 % for LED based emitters. Therefore, changes of supply voltage cause the least effect on the level of current harmonics of LED based emitters and then the emitters with electrode-less lamps. Change of the level of supply voltage causes the greatest effect on the level of current harmonics of HPSL based irradiators. Mathematical models of dependence of THDi on the level of supply voltage for greenhouse emitters equipped with LED, electrode-less lamps and HPSL lamps were formulated. These mathematical models may be used for calculations of total current when selecting transformers and supply cable lines for greenhouse lighting devices, for design of new or reconstruction of existing irradiation systems of greenhouse facilities, and for calculation of power losses in power supply networks of greenhouse facilities during feasibility studies for energy saving and energy efficiency increasing projects.

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