A Single-Phase Electromagnetic Transformer with an Adjustable Output Voltage

2019 ◽  
Author(s):  
Junwei Cui ◽  
Liyan Qu ◽  
Wei Qiao
Keyword(s):  
Output Voltage ◽  
Single Phase

A Structural-Algorithmic and Parametric Synthesis of Single-Phase Voltage Source Inverters for Increased Power Capacity

2021 ◽  
Vol 2 (2) ◽  
pp. 44-53
Author(s):  
GENNADY S. MYTSYK ◽  
◽  
ZAW HTET HEIN ◽  
Keyword(s):  
Energy Flow ◽  
Output Voltage ◽  
Power Plants ◽  
Single Phase ◽  
Voltage Source ◽  
Phase Voltage ◽  
Power Capacity ◽  
Voltage Source Inverters ◽  
Solar Power Plants ◽  
Output Filter

The recent interest of developers of new technology in studying a structural and algorithmic synthesis (SAS) of voltage source inverters (VSI) for solar power plants (SPP) is stemming from a growing need to solve problems in connection with the revealed new possibilities of converting energy flow (from DC to AC) with better energy efficiency by reducing the depth of its pulse modulation. This problem is solved by using more rational structural and algorithmic solutions. It is shown that for SPPs for a capacity of about 1 MW and more, it is more expedient to construct inverters based on the energy flow multichannel conversion principle. Given a limited power capacity of the transistor components, the application of this principle allows the problem to be solved in fact without using an output filter. The output voltage waveform is shaped using the energy flow pulse-amplitude modulation (PAM), and its M parts are summed in the output circuit by out using M winding transfilters (M-TF). The proposed method for carrying out combined SAS of single-phase voltage source inverters with multichannel conversion is considered, which consists in using an N-level single-phase VSI (N-SPVSI) in each of the M channels with the voltage levels optimized in terms of the minimum total harmonic distortion (THD). The resulting voltage of this class of single-phase inverters, designated as MxN-SPVSI, is formed by the corresponding phase shift of the channel voltages followed by summing the channel currents by M-TF. It is shown that the resulting output voltage levels are also close to their values optimized with respect to the minimum of the THD indicator. The results from a comparative analysis of two options — a single-channel 8-level inverter and a four-channel 8-level inverter are given. For the second option, only one intermediate voltage tap in the solar battery is required (instead of seven taps in the first option) along with modern transistor components that are available for practical implementation. In both options, the THD value less than 5% is obtained with almost no need of using an output filter. The presented results provide a certain information and methodological support for system designing of single-phase voltage source inverters as applied to the specific features of solar power plants. Three-phase inverters can be built on the basis of three single-phase inverters with galvanic isolation of the power sources for each phase.

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

Electronics ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 154
Author(s):  
Wei Yao ◽  
Jiamin Cui ◽  
Wenxi Yao
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Voltage Source ◽  
Current Loop ◽  
Deadbeat Control ◽  
Additional Advantage ◽  
Power Sources ◽  
Pwm Inverter ◽  
Single Phase Inverter

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.

scholarly journals Standalone Operation of Modified Seven-Level Packed U-Cell (MPUC) Single-Phase Inverter

Electronics ◽  
2019 ◽  
Vol 8 (3) ◽  
pp. 268 ◽  
Author(s):  
Ali Shojaei ◽  
Bahram Najafi ◽  
Hani Vahedi
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Multilevel Inverter ◽  
Switching Frequency ◽  
Voltage Waveform ◽  
Multilevel Inverters ◽  
Design Considerations ◽  
Single Phase Inverter ◽  
Load Types ◽  
Switch Voltage

In this paper the standalone operation of the modified seven-level Packed U-Cell (MPUC) inverter is presented and analyzed. The MPUC inverter has two DC sources and six switches, which generate seven voltage levels at the output. Compared to cascaded H-bridge and neutral point clamp multilevel inverters, the MPUC inverter generates a higher number of voltage levels using fewer components. The experimental results of the MPUC prototype validate the appropriate operation of the multilevel inverter dealing with various load types including motor, linear, and nonlinear ones. The design considerations, including output AC voltage RMS value, switching frequency, and switch voltage rating, as well as the harmonic analysis of the output voltage waveform, are taken into account to prove the advantages of the introduced multilevel inverter.

scholarly journals Harmonics reduction of a five-level inverter by unbalanced carriers and over-modulation techniques

2018 ◽  
Vol 7 (3) ◽  
pp. 1059
Author(s):  
Mustafa Fawzi Mohammed ◽  
Ali Husain Ahmad ◽  
AbdulRahim Thiab Humod
Keyword(s):  
Fundamental Frequency ◽  
Output Voltage ◽  
Single Phase ◽  
Harmonic Distortion ◽  
Total Harmonic Distortion ◽  
Modulation Method ◽  
Labview Software ◽  
Design And Implementation ◽  
Modulation Techniques ◽  
Multi Level

The most concerns in the inverter's design are about, how to make the output voltage of the inverter sinusoidal at the desired fundamental frequency with low total harmonic distortion (THD). This paper presents a design and implementation of single-phase five-level inverter which is powered by single dc source and based on T-type multi-level inverters construction. The proposed inverter is built mainly by six IGBTs and two diodes. The used modulation technique is based on using two triangular carriers at 2000 Hz frequency and shifted by phase opposition disposition (POD) method. The carriers are made slightly unbalanced with their amplitudes. The over-modulation method is also introduced in the design to get the lowest possible THD effect without using filters. The inverter is simulated by MATLAB SIMULINK, implemented practically, and tested with the help of LabVIEW software.  

Maximum Boost Control for 7-level Z-source Cascaded H-Bridge Inverter

2017 ◽  
Vol 8 (2) ◽  
pp. 739
Author(s):  
R. Palanisamy ◽  
K. Vijayakumar
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Boost Converter ◽  
Voltage Source ◽  
Constant Voltage ◽  
Harmonic Content ◽  
Duty Cycles ◽  
Voltage Stress ◽  
Power Switches ◽  
Boost Control

This paper proposes maximum boost control for 7-level z-source cascaded h-bridge inverter and their affiliation between voltage boost gain and modulation index. Z-source network avoids the usage of external dc-dc boost converter and improves output voltage with minimised harmonic content. Z-source network utilises distinctive LC impedance combination with 7-level cascaded inverter and it conquers the conventional voltage source inverter. The maximum boost controller furnishes voltage boost and maintain constant voltage stress across power switches, which provides better output voltage with variation of duty cycles. Single phase 7-level z-source cascaded inverter simulated using matlab/simulink.

scholarly journals A Single-Phase Nine-Level Boost Inverter

Energies ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 394 ◽  
Author(s):  
Dai-Van Vo ◽  
Minh-Khai Nguyen ◽  
Duc-Tri Do ◽  
Youn-Ok Choi
Keyword(s):  
Output Voltage ◽  
Single Phase ◽  
Simple Structure ◽  
Input Voltage ◽  
Maximum Output ◽  
Power Switches ◽  
In Series ◽  
Simulation And Experiment ◽  
Laboratory Prototype ◽  
Circuit Configuration

A novel single-phase nine-level boost inverter is proposed in this paper. The proposed inverter has an output voltage which is higher than the input voltage by switching capacitors in series and in parallel. The maximum output voltage of the proposed inverter is determined by using the boost converter circuit, which has been integrated into the circuit. The proposed topology is able to invert the multilevel voltage with the high step-up output voltage, simple structure and fewer power switches. In this paper, the circuit configuration, the operating principle, and the output voltage expression have been derived. The proposed converter has been verified by simulation and experiment with the help of PSIM software and a laboratory prototype. The experimental results match the theoretical calculation and the simulation results.

Sign in / Sign up

Export Citation Format

Share Document