Active Circulating Current Reduction for Three-Phase Three-Level Modular Photovoltaic Grid-Connected System

2013 ◽  
Vol 339 ◽  
pp. 568-573 ◽  
Author(s):  
Fu Sheng Wang ◽  
Xiao Fei Wang ◽  
Xing Zhang ◽  
Zhang Ping Shao ◽  
Ping Liu
Keyword(s):  
Low Frequency ◽  
Equivalent Model ◽  
Modular System ◽  
Average Reference ◽  
Circulating Current ◽  
Three Phase ◽  
Exciting Source ◽  
Reduction Methods ◽  
Current Reduction ◽  
And Control

According to the active circulating current existing in the three-phase three-level modular photovoltaic grid-connected system, an equivalent model of the active circulating current is built on the basis of the topology and control of the modular system, and the exciting source and the impedance are analyzed in detail. One kind of current-sharing loop is proposed. The error between the average reference current and the feedback current with PI controller is added to the output of the DC voltage loop. Thus the impedance of the active circulating current is enhanced within low frequency range and the active circulating current is reduced effectively. Lastly, A 10kW three-phase three-level modular photovoltaic grid-connected system is built, and experimental results demonstrate the correctness of the model analysis and reduction methods.

Zero-Sequence Circulating Current Reduction for Three-Phase Three-Level Modular Photovoltaic Grid-Connected System

2013 ◽  
Vol 339 ◽  
pp. 539-544
Author(s):  
Fu Sheng Wang ◽  
Xiao Fei Wang ◽  
Zhang Ping Shao ◽  
Xing Zhang
Keyword(s):  
High Frequency ◽  
Low Frequency ◽  
Frequency Component ◽  
Equivalent Model ◽  
High Frequency Component ◽  
Circulating Current ◽  
Three Phase ◽  
Zero Sequence ◽  
Reduction Methods ◽  
Current Reduction

An equivalent model is established for zero-sequence circulating current (ZSCC) in three-phase three-level modular photovoltaic grid-connected system, and ZSCC is classified by frequency into high-frequency and low-frequency components. A parallel solution based on improved LCL filter is proposed to reduce high frequency component of ZSCC, and the low-frequency component of ZSCC can be reduced by using the ZSCC controller. The ZSCC model analysis and reduction methods are verified by experimental results based on a 10 kW three-phase three-level modular photovoltaic grid-connected system.

Circulating Current Reduction for Three-Phase Back-to-Back Transformerless Inverter With SPWM-Based D-∑ Digital Control

2017 ◽  
Vol 32 (2) ◽  
pp. 1591-1601 ◽  
Author(s):  
Tsai-Fu Wu ◽  
Po-Hung Lee ◽  
Li-Chiun Lin ◽  
Chih-Hao Chang ◽  
Yu-Kai Chen
Keyword(s):  
Digital Control ◽  
Circulating Current ◽  
Three Phase ◽  
Current Reduction

Identificación de polaridad de los devanados en un motor trifásico de 6 terminales

2019 ◽  
pp. 13-19
Author(s):  
José Luis Viramontes-Reyna ◽  
Josafat Moreno-Silva ◽  
José Guadalupe Montelongo-Sierra ◽  
Erasmo Velazquez-Leyva
Keyword(s):  
Low Cost ◽  
Voltage Reference ◽  
Three Phase ◽  
Voltage Phase ◽  
The Law ◽  
And Control

This document presents the results obtained from the application of the law of Lens to correctly identify the polarity of the windings in a three-phase motor with 6 exposed terminals, when the corresponding labeling is not in any situation; Prior to identifying the polarity, it should be considered to have the pairs of the three windings located. For the polarity, it is proposed to feed with a voltage of 12 Vrms to one of the windings, which are identified randomly as W1 and W2, where W1 is connected to the voltage phase of 12 Vrms of the signal and W2 to the voltage reference to 0V; by means of voltage induction and considering the law of Lens, the remaining 4 terminals can be identified and labeled as V1, V2, U1 and U2. For this process a microcontroller and control elements with low cost are used.

A Novel Two-phase Soft Starter Used for Three-phase Asynchronous Motors

2020 ◽  
Vol 13 (8) ◽  
pp. 1175-1182
Author(s):  
Jingwen Chen ◽  
Hongshe Dang
Keyword(s):  
Pulse Generation ◽  
Power Module ◽  
Two Phase ◽  
Power Semiconductor ◽  
Starting Current ◽  
Semiconductor Switches ◽  
Soft Starter ◽  
Three Phase ◽  
And Control ◽  
Driving Circuit

Background: Traditional thyristor-based three-phase soft starters of induction motor often suffer from high starting current and heavy harmonics. Moreover, both the trigger pulse generation and driving circuit design are usually complicated. Methods: To address these issues, we propose a novel soft starter structure using fully controlled IGBTs in this paper. Compared to approaches of traditional design, this structure only uses twophase as the input, and each phase is controlled by a power module that is composed of one IGBT and four diodes. Results: Consequently, both driving circuit and control design are greatly simplified due to the requirement of fewer controlled power semiconductor switches, which leads to the reduction of the total cost. Conclusion: Both Matlab/Simulink simulation results and experimental results on a prototype demonstrate that the proposed soft starter can achieve better performances than traditional thyristorbased soft starters for Starting Current (RMS) and harmonics.

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