scholarly journals Calculation of Semiconductor Power Losses of a Three-Phase Quasi-Z-Source Inverter

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1642
Author(s):  
Ivan Grgić ◽  
Dinko Vukadinović ◽  
Mateo Bašić ◽  
Matija Bubalo

This paper presents two novel algorithms for the calculation of semiconductor losses of a three-phase quasi-Z-source inverter (qZSI). The conduction and switching losses are calculated based on the output current-voltage characteristics and switching characteristics, respectively, which are provided by the semiconductor device manufacturer. The considered inverter has been operated in a stand-alone operation mode, whereby the sinusoidal pulse width modulation (SPWM) with injected 3rd harmonic has been implemented. The proposed algorithms calculate the losses of the insulated gate bipolar transistors (IGBTs) and the free-wheeling diodes in the inverter bridge, as well as the losses of the impedance network diode. The first considered algorithm requires the mean value of the inverter input voltage, the mean value of the impedance network inductor current, the peak value of the phase current, the modulation index, the duty cycle, and the phase angle between the fundamental output phase current and voltage. Its implementation is feasible only for the Z-source-related topologies with the SPWM. The second considered algorithm requires the instantaneous values of the inverter input voltage, the impedance network diode current, the impedance network inductor current, the phase current, and the duty cycle. However, it does not impose any limitations regarding the inverter topology or switching modulation strategy. The semiconductor losses calculated by the proposed algorithms were compared with the experimentally determined losses. Based on the comparison, the correction factor for the IGBT switching energies was determined so the errors of both the algorithms were reduced to less than 12%.

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4216
Author(s):  
Ivan Grgić ◽  
Dinko Vukadinović ◽  
Mateo Bašić ◽  
Matija Bubalo

A quasi-Z-source inverter (qZSI) is a single-stage inverter that enables a boost of the input dc voltage through the utilization of a so-called shoot-through state (STS). Generally, the efficiency of the qZSI depends on the utilized STS injection method to a significant extent. This paper presents a novel method of STS injection, called the zero-sync method, in which the STS occurrence is synchronized with the beginning of the zero switching states (ZSSs) of the three-phase sinusoidal pulse width modulation (SPWM). In this way, compared to the conventional STS injection method, the total number of switchings per transistor is reduced. The ZSSs are detected by utilizing the SPWM pulses and the logic OR gates. The desired duration of the STS is implemented by utilizing the LM555CN timer. The laboratory setup of the three-phase qZSI in the stand-alone operation mode was built to compare the proposed zero-sync method with the conventional STS injection method. The comparison was carried out for different values of the switching frequency, input voltage, duty ratio, and load power. As a result of the implementation of the zero-sync method, the qZSI efficiency was increased by up to 4%. In addition, the unintended STSs, caused by the non-ideal switching dynamics of the involved transistors, were successfully eliminated by introducing the optimal dead-time as part of the modified zero-sync method. As a result, the efficiency was increased by up to 12% with regard to the conventional method.


2013 ◽  
Vol 64 (5) ◽  
pp. 331-333
Author(s):  
Hyun-Lark Do

Abstract This paper presents a zero-voltage-switching (ZVS) full-bridge based DC-DC converter with linear voltage gain according to duty cycle. The proposed converter is based on an asymmetrical pulse-width-modulation (APWM) full-bridge converter which has various advantages over other converters. However, it has some drawbacks such as limited maximum duty cycle to 0.5 and narrow input range. The proposed converter overcomes these problems. The duty cycle is not limited and input voltage range is wide. Also, the ZVS operation of all power switches is achieved. Therefore, switching losses are significantly reduced and high-efficiency is obtained. Steady-state analysis and experimental results for the proposed converter are presented to validate the feasibility and the performance of the proposed converter.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mohannad Jabbar Mnati ◽  
Dimitar V. Bozalakov ◽  
Alex Van den Bossche

Nowadays, most three-phase, “off the shelf” inverters use electrolytic capacitors at the DC bus to provide short term energy storage. However, this has a direct impact on inverter lifetime and the total cost of the photovoltaic system. This article proposes a novel control strategy called a 120° bus clamped PWM (120BCM). The 120BCM modulates the DC bus and uses a smaller DC bus capacitor value, which is typical for film capacitors. Hence, the inverter lifetime can be increased up to the operational lifetime of the photovoltaic panels. Thus, the total cost of ownership of the PV system will decrease significantly. Furthermore, the proposed 120BCM control strategy modulates only one phase current at a time by using only one leg to perform the modulation. As a result, switching losses are significantly reduced. The full system setup is designed and presented in this paper with some practical results.


Energies ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2709
Author(s):  
Xuchen Wang ◽  
Hao Yan ◽  
Giampaolo Buticchi ◽  
Chunyang Gu ◽  
He Zhang

Multiphase drives are entering the spotlight of the research community for transportation applications with their high power density and the possibility of high fault tolerance. The multi three-phase drive is one of the main types of multiphase drives that allows for the direct adoption of commercial three-phase converters and high control flexibility. The elimination of high-frequency current harmonics will reduce the flux linkage harmonics, torque ripple, vibration and noise in machine drives. Therefore, this work introduces a new method to the modelling of equivalent phase current in multi three-phase drives with the double integral Fourier analysis method. A new carrier-based pulse-width modulation (CPWM) method is introduced to reduce the equivalent phase current harmonics by applying proper carrier phase angle to each subsystem in the multi three-phase drives. The proposed angles of carrier signals are analyzed for quadruple three-phase drives, and the corresponding experimental results confirm the significance of the proposed phase-shifted CPWM method to eliminate the equivalent phase current harmonics.


2019 ◽  
Vol 63 (3) ◽  
pp. 169-177
Author(s):  
Mohamed Amine Khelif ◽  
Azeddine Bendiabdellah ◽  
Bilal Djamal Eddine Cherif

Currently, with the power electronics evolution, a major research axis is oriented towards the diagnosis of converters supplying induction machines. Indeed, a converter such as the inverter is susceptible to have structural failures such as faulty leg and/or open-circuit IGBT faults. In this paper, the detection of the faulty leg and the localization of the open-circuit switch of an inverter are investigated. The fault detection technique used in this work is based essentially upon the monitoring of the root mean square (RMS) value and the calculation of the mean value of the three-phase currents. In the first part of the paper work, the faulty leg is detected by monitoring the RMS value of the three-phase currents and comparing them to the nominal value of the phase current. The second part, the open-circuit IGBT fault is localized simply by knowing the polarity of the calculated mean value current of the faulty phase. The work is first accomplished using simulation work and then the obtained simulation results are validated by experimental work conducted in our LDEE laboratory to illustrate the effectiveness, simplicity and rapidity of the proposed technique.


2015 ◽  
Vol 24 (09) ◽  
pp. 1550132 ◽  
Author(s):  
Li-Ye Cheng ◽  
Xin-Quan Lai

A mode-selectable oscillator (OSC) with variable duty cycle for improved charge pump efficiency is proposed in this paper. The novel OSC adjusts its duty cycle according to the operation mode of the charge pump, thus improves the charge-pump efficiency and dynamic performance. The control of variable duty cycle is implemented in digital logic hence it provides robust noise immunity and instantaneous response. The OSC and the charge-pump have been implemented in a 0.6-μm 40-V CMOS process. Experimental results show that the peak efficiency is 92.7% at 200-mA load, the recovery time is less than 25 μs and load transient is 15 mV under 500-mA load variation. The system is able to work under a wide range of input voltage (V IN ) in all modes with low EMI.


Author(s):  
Saidah Saidah ◽  
Hari Sutiksno ◽  
Bambang Purwahyudi ◽  
Taufik Taufik

This paper introduces the modelling of a novel three phase AC-AC converter with indirect use of a capacitor as DC voltage link. The proposed converter has high efficiency because it uses Space Vector PWM (SVPWM) technique at both rectificier and inverter stages to operate the pulse width modulation in IGBT switches. The novel converter is equipped with a power factor control to shape the rectifier input current waveform to be sinusoidal and to be in phase with the input voltage. To keep the DC voltage stable, the converter utilizes PI controllers. Simulations are conducted for output voltage from 120 to 300 Volts with output frequency ranging from 30 Hz to 60 Hz. The simulation results show that the converter is able to maintain stable the DC voltage and current. Furthermore, the model demonstrates the benefits of proposed converter in terms of acquiring high input power factor and sinusoidal current waveform at the output side of the inverter.


Author(s):  
I Ketut Wiryajati ◽  
A.D Giriantari ◽  
Lie Jasa ◽  
I N. S. Kumara

Abstract— An induction motors  (IM) in many industries is used because it has several advantages, such as a very simple and strong construction, the price is relatively cheap, has good efficiency, power factor is quite good, and maintenance is easier. Besides the advantages of induction motors also have disadvantages, one disadvantage of induction motors is not being able to maintain a constant speed when there is a change in load. If the load changes, the speed of the induction motor will decrease. One method of regulating the speed of an induction motor presented in this study is the regulation of an induction motor using a carrier based PWM (CBPWM) inverter with the field oriented control  (FOC) technique. The estimation of rotor rotation, torque and flux is done by carrier- based PWM  technique which is given input voltage and stator current. To achieve the desired flux and torque, estimation is used as feedback in the control system. In this study, it will be simulated the induction motor speed regulation with a carrier base-based inverter using Matlab. The results obtained through simulation show the length of time to reach the reference speed for speeds of 1500 rpm and 1450 rpm is around 0.45 seconds. And THD  average 2,675%.


Author(s):  
Sony Prakarsa Putra ◽  
Zulwisli Zulwisli

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.


Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3331
Author(s):  
Wang Hu ◽  
Yunxiang Xie ◽  
Zhiping Wang ◽  
Zhi Zhang

This paper presents a novel three-phase current source rectifier (CSR) for AC/DC step-down voltage conversion to reduce voltage and current stress. The proposed converter features an asymmetrical connection between upper and lower arms compared with conventional CSRs, but has the same number of devices. With the proposed asymmetrical structure and modified space vector pulse width modulation (SVPWM) scheme, half of transistors only need to withstand half of the line-to-line voltage rather than the full line-to-line voltage, and its DC link current can be shared by multiple switches in freewheeling periods. Therefore, it is able to bring about a significant reduction in voltage and current stress, allowing for an improvement in the converter without additional cost. The topological structure, operation principles, and comparative analysis are specifically presented. Finally, an experimental prototype is built up to verify the performance of the proposed converter.


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