A hybrid fuzzy-repetitive control scheme for single-phase CVCF inverters

Author(s):  
Li Jian ◽  
Kang Yong ◽  
Chen Jian
2019 ◽  
Vol 9 (6) ◽  
pp. 1198
Author(s):  
Xiaohui Yang ◽  
Peiyun Liu ◽  
Shaoping Xu ◽  
Shichao Liu

There exist several challenges in the implementation of proportional multiple quasi-resonant (PMQR) control strategies in single-phase grid-connected H6 inverters, such as high computational costs and design complexity. To overcome these challenges, this paper proposes a proportional multiple quasi-resonant (PMQR)-type repetitive control (PMQR-type RC) scheme for single-phase grid-connected H6 inverters. In the control scheme, a repetitive controller and a proportional controller run in parallel. The repetitive controller is to improve the steady-state harmonics compensation ability, while the proportional controller can enhance the transient performance of the system. Both theoretical stability analysis and detailed design steps regarding the proposed control scheme are introduced. Finally, comparison results on a typical single-phase grid-connected H6 inverter with LC filter under a variety of control methods verify the capability of suppressing harmonics and the robust performance of the proposed control strategy against grid disturbances.


Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4225
Author(s):  
Chengbi Zeng ◽  
Sudan Li ◽  
Hanwen Wang ◽  
Hong Miao

Repetitive control (RC) is gradually used in inverters tied with weak grid. To achieve the zero steady-state error tracking of inverter current and compensate the harmonic distortion caused by frequency fluctuation, a frequency adaptive (FA) control scheme for LCL-type inverter connected with weak grid is proposed. This scheme adopts a proportional resonance (PR) controller in parallel with RC (PRRC) to overcome the disadvantages caused by RC inherent one-cycle time delay. A fractional delay (FD) filter based on the Newton structure is proposed to approximate the fraction item of fs/f, where fs and f are sample frequency and grid frequency, respectively. The structure of the proposed FD filter is relatively simple; moreover, coefficients of the filter maintain constant so as not to need online tuning even when grid frequency fluctuates, which decreases the computational burden considerably. The feasibility and effectiveness of the proposed FA control scheme, named as Newton-FAPRRC, are all verified by the simulation and experimental results.


Author(s):  
Wei Yao ◽  
Zhaoming Qian

In this paper, an improved load sharing control scheme is presented, which is able to improve the transient response and power sharing accuracy of parallel-connected inverters used in microgrid. It also shows how the improved droop method can be easily adapted to account for the operation of parallel-connected inverters, providing good performance under the variation and disturbance of loads, as well as achieving good steady-state objectives and transient performance. Two DSP-based single-phase Microgrid inverters are designed and implemented. Simulation and experimental results are all reported, confirming the validity of the proposed control technique.


2014 ◽  
Vol 644-650 ◽  
pp. 523-526
Author(s):  
Yun Ling ◽  
Huan Chen ◽  
Fei Li

In the wrapping process of magnet wire, as the haulage speed of master motor varies periodically, it is difficult for slave wrapping motor to track master motor due to the mechanical resonance, which destabilizes the wrapping pitch. In the proposed system, the synchronization speed control scheme of master-slave motor based on repetitive control compensation is employed. In the process of control, real-time spectrum analysis of the haulage speed is given, which can be used to adjust the parameters of wrapping speed controller adaptively with the acquired characteristic information of the mechanical resonant. Simulation shows that wrapping speed can track haulage speed well in the proposed system, and the maximum tracking synchronous deviation can be reduced to 56% of that in the system without repetitive control.


Author(s):  
Peethala Rajiv Roy ◽  
P. Parthiban ◽  
B. Chitti Babu

Abstract This paper deals with implementation of a single-phase three level converter system under low voltage condition. The frequency of the switches is made constant and involves change in ${t_{on}}$ and ${t_{off}}$ duration. For this condition the pulse width modulation control scheme for a single phase three level rectifier is developed to improve the power quality. The hysteresis current control technique is adopted to bring forth three-level PWM on the dc side of the bridge rectifier and to achieve high power factor and low harmonic distortion. Based on the proposed control scheme, the line current is driven to follow the sinusoidal current command which is in phase with the supply voltage. By using three-level voltage pattern the blocking voltage of each power device is clamped to half of the dc link voltage. The simulation and experimental results of 20W converter under low input voltage condition are shown to verify the circuit performance. Open loop simulation and hardware tests are implemented by applying a low voltage of 15 V(rms) on the input side.


2019 ◽  
Vol 2019 (16) ◽  
pp. 1683-1686
Author(s):  
Feng Xu ◽  
Yi Lu ◽  
Xiaohua Xuan ◽  
Haihong Yu ◽  
Peng Qiu ◽  
...  

Sign in / Sign up

Export Citation Format

Share Document