scholarly journals Hybrid Pulse Width Modulation Strategy of a High-Frequency Link Three-Phase Four-Leg Matrix Converter Based on Compensation Theory

2019 ◽  
Vol 10 (1) ◽  
pp. 39
Author(s):  
Rutian Wang ◽  
Fuxu Wang ◽  
Haining Pan ◽  
Sutong Liu
Keyword(s):  
High Frequency ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Matrix Converter ◽  
Compensation Method ◽  
Switching Frequency ◽  
Control Logic ◽  
Compensation Strategy ◽  
High Switching Frequency ◽  
Three Phase

A high-frequency link (HFL) three-phase four-leg matrix converter (MC) can output three-phase balanced voltage for unbalanced load conditions. It is an inverter with great development potential. This paper presents a hybrid pulse width modulation (HPWM) strategy for a four-wire matrix converter based on the fourth bridge leg compensation method. Firstly, the rear-stage topology of a high-frequency link three-phase four-leg matrix converter is decoupled into two sets of ordinary three-phase four-wire inverters. Then the compensation strategy is applied to separate the fourth bridge leg from the coupling of the ordinary inverter and realize its independent control. Under the theory of compensation, the fourth bridge leg plays a role in compensating the deviation of the neutral point potential when the load is unbalanced, the fourth bridge leg does not need to work when the load is balanced. Finally, the fourth bridge leg modulation wave obtained by the compensation method is combined with the front three bridge leg modulation waves to perform the coupling control using the hybrid pulse width modulation strategy. It has changed the problem that the previous hybrid pulse width modulation strategy cannot be directly applied to the four-wire matrix converter. This strategy is simple to control, without adding any auxiliary commutation detection circuitry, can effectively solve the inherent commutation problem in the bidirectional switch tube of the four-wire matrix converter. It simplifies the complexity of the system, reduced control cost, and high switching loss caused by high switching frequency. The fast adjustment function of compensation strategy makes the dynamic response performance of system under load fluctuation state more prominent, the harmonic distortion rate is smaller. The perfect combination of two strategies allows the high-frequency link three-phase four-leg matrix converter with any form of load to give full play to its structural advantages. The related work verifies the feasibility and effectiveness of the modulation method and control logic.

scholarly journals Common-Mode Reduction SVPWM for Three-Phase Motor Fed by Two-Level Voltage Source Inverter

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3884
Author(s):  
Jian Zheng ◽  
Mingcheng Lyu ◽  
Shengqing Li ◽  
Qiwu Luo ◽  
Keyuan Huang
Keyword(s):  
High Frequency ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Voltage Source ◽  
Switching Frequency ◽  
Voltage Source Inverter ◽  
Large Magnitude ◽  
Common Mode ◽  
Common Mode Voltage ◽  
Three Phase

Aiming at the problem of large magnitude and high frequency of common-mode voltage (CMV) when space vector pulse width modulation (SVPWM) is used in a three-phase motor fed by a two-level voltage source inverter, a common-mode reduction SVPWM (CMRSVPWM) is studied. In this method, six new sectors are obtained by rotating six sectors of conventional SVPWM by 30°. In odd-numbered sectors, only three non-zero vectors with odd subscripts are used for synthesis, while in even-numbered sectors, only three non-zero vectors with even subscripts are used for synthesis. The actuation durations of three non-zero vectors in each switching period in each sector are given. Simulation and experimental results show that, compared with the conventional SVPWM, the CMV magnitude of CMRSVPWM is reduced by 66.67% and the CMV frequency of CMRSVPWM is reduced from the original switching frequency to the triple fundamental frequency. At the same time, the current, torque and speed of the motor are still good.

scholarly journals A Review of Modular Multilevel Converters for Stationary Applications

2020 ◽  
Vol 10 (21) ◽  
pp. 7719
Author(s):  
Yang Wang ◽  
Ahmet Aksoz ◽  
Thomas Geury ◽  
Salih Baris Ozturk ◽  
Omer Cihan Kivanc ◽  
...  
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Low Voltage ◽  
Current Control ◽  
Switching Frequency ◽  
Power Losses ◽  
Circulating Current ◽  
High Switching Frequency ◽  
Wide Range ◽  
Balancing Control

A modular multilevel converter (MMC) is an advanced voltage source converter applicable to a wide range of medium and high-voltage applications. It has competitive advantages such as quality output performance, high modularity, simple scalability, and low voltage and current rating demand for the power switches. Remarkable studies have been carried out regarding its topology, control, and operation. The main purpose of this review is to present the current state of the art of the MMC technology and to offer a better understanding of its operation and control for stationary applications. In this study, the MMC configuration is presented regarding its conventional and advanced submodule (SM) and overall topologies. The mathematical modeling, output voltage, and current control under different grid conditions, submodule balancing control, circulating current control, and modulation methods are discussed to provide the state of the MMC technology. The challenges linked to the MMC are associated with submodule balancing control, circulating current control, control complexity, and transient performance. Advanced nonlinear and predictable control strategies are expected to improve the MMC control and performance in comparison with conventional control methods. Finally, the power losses associated with the advanced wide bandgap (WBG) power devices (such as SiC, GaN) are explored by using different modulation schemes and switching frequencies. The results indicate that although the phase-shifted carrier-based pulse width modulation (PSC-PWM) has higher power losses, it outputs a better quality voltage with lower total harmonic distortion (THD) in comparison with phase-disposition pulse width modulation (PD-PWM) and sampled average modulation pulse width modulation (SAM-PWM). In addition, WBG switches such as silicon carbide (SiC) and gallium nitride (GaN) devices have lower power losses and higher efficiency, especially at high switching frequency in the MMC applications.

scholarly journals Variable-Frequency Pulse Width Modulation Circuits for Resonant Wireless Power Transfer

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3656
Author(s):  
Li-Chuan Tang ◽  
Shyr-Long Jeng ◽  
Edward-Yi Chang ◽  
Wei-Hua Chieng
Keyword(s):  
Duty Cycle ◽  
High Frequency ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Wireless Power Transfer ◽  
Switching Frequency ◽  
Variable Frequency ◽  
Power Transfer ◽  
Wireless Power ◽  
Frequency Pulse

In this paper, we develop a variable-frequency pulse width modulation (VFPWM) circuit for input control of 6.78-MHz resonant wireless power transfer (WPT) systems. The zero-voltage switching control relies on the adjustments of both duty cycle and switching frequency for the class-E amplifier used in the WPT as the power transmission unit. High-frequency pulse wave modulation integrated circuits exist, but some have insufficiently high frequency or unfavorable resolution for duty cycle tuning. The novelty of this work is the VFPWM circuit design that we put together. A voltage-controlled oscillator (VCO) of radio frequency and capacitor-coupled difference amplifiers are used to simultaneously perform the frequency and duty cycle tuning required in resonant WPT applications. Different circuit topologies of VFPWM are compared analytically and numerically. The most favorable circuit topology, enabling independent control of the frequency and duty cycle, is employed in experiments. The experimental results demonstrate the validity of the novel VFPWM, which is capable of operating at 6.78 MHz and has a duty ratio adjustable from 20% to 45% of the range applicable in the resonant WPT applications.

scholarly journals Analysis and Implementation of Unipolar PWM Strategies for Three Phase Cascade Multilevel Inverter Fed Induction Motor Drive

2018 ◽  
Vol 7 (3) ◽  
pp. 245
Author(s):  
Ravikumar Bhukya ◽  
P. Satish Kumar
Keyword(s):  
Induction Motor ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Switching Frequency ◽  
Good Opportunity ◽  
Single Carrier ◽  
Unipolar Pulse ◽  
Three Phase ◽  
Sampling Pulse ◽  
Multi Level

This paper presents unipolar pulse width modulation technique with sinusoidal sampling pulse width modulation are analyzed for three-phase five-level, seven-level, nine-level and eleven-level cascaded multi-level inverter. The unipolar PWM method offers a good opportunity for the realization of the Three-phase inverter control, it is better to use the unipolar PWM method with single carrier wave compared to two reference waves. In such case the motor harmonic losses will be considerably lower.The necessary calculations for generation of unipolar pulse width modulation strategies have presented in detail. The unipolar SPWM voltage switching scheme is selected in this paper because this method offers the advantages of effectively doubling the switching frequency of the inverter voltage. The cascaded multi level inverter fed induction motor is simulated and compared the total harmonic distroction for all level (five-level, seven-level, nine-level and elevel-level)of the inverter. Theoretical investigations were confirmed by the digital simulations using MATLAB/SIMULINK software.

A Low Cost MCU Based Single Phase Sinusoidal Pulse-Width-Modulated Inverter

2014 ◽  
Vol 1014 ◽  
pp. 241-244
Author(s):  
Peng Lai Chen ◽  
Chun Yu Lin ◽  
Yu Lin Juan ◽  
Te Chau Chen ◽  
Chin Sung Lin
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Low Cost ◽  
Harmonic Distortion ◽  
Load Resistance ◽  
Sine Wave ◽  
Switching Frequency ◽  
Single Chip ◽  
High Switching Frequency ◽  
Sampling Points

Sinusoidal pulse width modulation (SPWM) technique has been widely used in inverters and motor driver ciruits. In this paper, SPWM was generated by a low cost HT66F50 single-chip, wherein the reduced sampling points of a sine wave, and the fewer sampling points were then used to produce SPWM singals. The full-bridge inverter was modulated by the high switching frequency SPWM for the high side switches and the 60Hz control signals for the low side switches. Thus, it not only reduces the required memory spacein MCU, but also reduces the switching power losses. When the SPWM frequency is 19.53 kHz or 11.72 kHz, the total harmonic distortion (THD) of the inverter’s output is less than 0.6% under the load resistance 50, which is in compliance with the specification of IEEE STD. 519-1992.

Sign in / Sign up

Export Citation Format

Share Document