The elimination of leakage currents in the neutral point clamped photovoltaic grid-connected inverter by the improved space vector pulse width modulation method

2013 ◽  
Vol 34 (10) ◽  
pp. 672-684 ◽  
Author(s):  
Qinjin Zhang ◽  
Yancheng Liu ◽  
Chuan Wang
Author(s):  
Nguyen Duc Minh ◽  
Bui Van Huy ◽  
Ngo Thi Quan ◽  
Nguyen Quang Ninh ◽  
Trinh Trong Chuong

This paper presents the design and simulation of three phase grid-connected inverter for photovoltaic systems with power ratings up to 5 kW. In this research, the application of Space Vector Pulse Width Modulation (SVPWM) technique for inverter is explored. With the use of SVPWM inverter, synchronization between the inverter and electrical grid follows the Phaselocked Loop (PLL) algorithm. The proposed design is simulated and validated by experimental results.


2012 ◽  
Vol 619 ◽  
pp. 156-159 ◽  
Author(s):  
Yan Liu ◽  
Xu Wang ◽  
Yan Xing ◽  
Dan Yang

Brushless doubly-fed machine (BDFM) is a new type of AC induction motor.It has a good applicable prospect as the variable frequency motors or the variable speed constant frequency generators. Although the advantage of the three-level inverter, there are also some problems of neutral point voltage balance in this method such as the unbalance of neutral point voltage. And the traditional principle of Three-level inverter space vector pulse width modulation method is to estimate the sectors and calculating a lot of trigonometric functions. To solve these problems, a novel method for the virtual space vector concept in G-H coordinate system is presented in this paper. The method proposed can omit the judging process of the sectors, reduce the calculating burden, and maintain the balance of neutral-point voltage between capacitances within a certain index modulation. The results of simulation are given to validate the improved virtual space vector modulation.


2021 ◽  
Vol 54 (4) ◽  
pp. 617-622
Author(s):  
Akhilesh Kumar ◽  
Pradip K. Sadhu ◽  
Jay Singh

Nowadays, the matrix converter (MC) has become the prominent power converter. Its unique qualities like single-stage ac to ac conversion, bidirectional power flow, sinusoidal response, unity power factor, and no need for dc-link makes it superior among all power converters. This archival literature investigates the various pulse width modulation (PWM) methods and proposed a novel pulse width modulation (PWM) method named Time Equivalent space vector pulse width modulation. In this article this novel modulation method is compared with exiting carrier-based pulse width control and space vector control methods for a 3 phase to 3 phase matrix converters. Simulation model is built in Matlab and comparative analysis based on total harmonic distortion (THD) will be given for different methods. Simulation results revealed that total harmonic distortion (THD) of Time Equivalent space vector PWM is least so this novel method is best and more efficient in comparison to others.


Machines ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 57
Author(s):  
Tao Jing ◽  
Andrey Radionov ◽  
Alexander Maklakov ◽  
Vadim Gasiyarov

In this paper, one model of flexible space-vector-based hybrid pulse width modulation (HPWM) transition algorithm consisting of selective harmonic elimination pulse width modulation (SHEPWM) and selective harmonic mitigation pulse width modulation (SHMPWM) is applied and examined in a 10kV grid with a three-level neutral point clamped (3L-NPC) grid-connected inverter. These two modulation techniques are used to produce the appropriate firing pulses for 3L-NPC grid-connected inverters in different cases. SHMPWM is adopted to the grid-connected inverters to mitigate the required odd non-triplen harmonics according to the requirements of grid codes EN 50160 and CIGRE WG 36-05, while the firing pulses generated using SHEPWM is used to eliminate the primary low-order odd non-triplen harmonics completely. Meanwhile, one smooth and fast transition scheme is proposed by providing a suitable switching angles set at the transition point. Finally, it is demonstrated and validated by the MATLAB/SIMULINK model that smooth and quick transition is realized and there is no sudden change of current during the transition, as expected. Furthermore, this hybrid PWM technique is universal for different PWM methods based on the specific operating conditions.


Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2598 ◽  
Author(s):  
Qiwu Luo ◽  
Jian Zheng ◽  
Yichuang Sun ◽  
Lijun Yang

Dual Y shift 30° six-phase motors are expected to be extensively applied in high-power yet energy-effective fields, and a harmonic-suppressing control strategy plays a vital role in extending their prominent features of low losses and ultra-quiet operation. Aiming at the suppression of harmonic voltages, this paper proposes a six-phase space vector pulse width modulation method based on an optimization model, namely OM-SVPWM. First, four adjacent large vectors are employed in each of 12 sectors on a fundamental sub-plane. Second, the optimization model is constructed to intelligently determine activation durations of the four vectors, where its objective function aims to minimize the synthesis result on a harmonic sub-plane, and its constraint condition is that the synthesis result on the fundamental sub-plane satisfies a reference vector. Finally, to meet the real-time requirement, optimum solutions are obtained by using general central path following algorithm (GCPFA). Simulation and experiment results prove that, the OM-SVPWM performs around 37% better than a state-of-the-art competitive SVPWM in terms of harmonics suppression, which promise the proposed OM-SVPWM conforms to the energy-effective direction in actual engineering applications.


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