scholarly journals Effective elimination of harmonics on the part of chosen dc bus in dual active type converter

2018 ◽  
Vol 7 (2.25) ◽  
pp. 53
Author(s):  
N Janaki ◽  
Dr R.Krishna Kumar
Keyword(s):  
Phase Shift ◽  
Square Wave ◽  
Active Type ◽  
Modulation Technique ◽  
Three Phase ◽  
Bridge Type ◽  
Dc Bus ◽  
Wave Control

In order to manage the flow of power in the dual bridge type converter, a modulation technique called phase shifted square wave is employed. As an outcome, increased range of ripples in current is resulted, and that further provokes the vibration in inductance and capacitance circuit. Due to this effect, there exists uncertainty in the value of current and voltage, failure of operating components and stress in the filter. To miti-gate the above ill effects, three level modulation can be done using three phase shift square wave control angles. These three angles now elimi-nate the harmonics in chosen DC link and the harmonic eliminating procedure is justified and simulated.  

scholarly journals Low-load Efficiency Improvement of a Three-Phase Bidirectional Isolated DC-DC Converter (3P-BIDC) Via Enhanced Switching Strategy

2018 ◽  
Vol 7 (4.35) ◽  
pp. 932 ◽  
Author(s):  
N. S. Mohd Sharifuddin ◽  
N. M. L. Tana ◽  
H. Akagi
Keyword(s):  
Phase Shift ◽  
Load Condition ◽  
Mode Switching ◽  
Switching Strategy ◽  
Burst Mode ◽  
Modulation Technique ◽  
Three Phase ◽  
Low Load ◽  
Low Efficiency ◽  
Load Conditions

This paper presents the system design, operation and enhanced switching strategy of a three-phase bidirectional isolated dc-dc converter (3P-BIDC). The paper discusses the operating modes of the 3P-BIDC using phase-shift modulation (PSM), with analysis on its soft-switching characteristics. The phase-shift modulation is the simplest modulation technique that can be applied to the 3P-BIDC. However, it comes with the consequences of low efficiency performance in the low-load conditions. Therefore, this paper investigates the improvement in efficiency of the 3P-BIDC during low-load condition using an enhanced switching strategy combining burst-mode switching and phase-shift modulation. The model of a 700-V, 100-kW, 20-kHz 3P-BIDC and the enhanced switching strategy are verified via simulation using PSCAD. The simulation results shows that the combination of burst-mode and phase-shift modulation technique improves the efficiency of the 3P-BIDC at low-load conditions.  

scholarly journals An Optimal Control Algorithm with Reduced DC-Bus Current Fluctuation for Multiple Charging Modes of Electric Vehicle Charging Station

2021 ◽  
Vol 12 (3) ◽  
pp. 107
Author(s):  
Tao Chen ◽  
Peng Fu ◽  
Xiaojiao Chen ◽  
Sheng Dou ◽  
Liansheng Huang ◽  
...  
Keyword(s):  
Electric Vehicle ◽  
Electric Vehicles ◽  
Control Algorithm ◽  
Current Fluctuation ◽  
Charging Station ◽  
Electric Vehicle Charging ◽  
Three Phase ◽  
Optimization Control ◽  
Dc Bus ◽  
Vehicle Charging

This paper presents a systematic structure and a control strategy for the electric vehicle charging station. The system uses a three-phase three-level neutral point clamped (NPC) rectifier to drive multiple three-phase three-level NPC converters to provide electric energy for electric vehicles. This topology can realize the single-phase AC mode, three-phase AC mode, and DC mode by adding some switches to meet different charging requirements. In the case of multiple electric vehicles charging simultaneously, a system optimization control algorithm is adopted to minimize DC-bus current fluctuation by analyzing and reconstructing the DC-bus current in various charging modes. This algorithm uses the genetic algorithm (ga) as the core of computing and reduces the number of change parameter variables within a limited range. The DC-bus current fluctuation is still minimal. The charging station system structure and the proposed system-level optimization control algorithm can improve the DC-side current stability through model calculation and simulation verification.

scholarly journals Absolute Phase Retrieval Using One Coded Pattern and Geometric Constraints of Fringe Projection System

2018 ◽  
Vol 8 (12) ◽  
pp. 2673 ◽  
Author(s):  
Xu Yang ◽  
Chunnian Zeng ◽  
Jie Luo ◽  
Yu Lei ◽  
Bo Tao ◽  
...  
Keyword(s):  
Phase Shift ◽  
Phase Retrieval ◽  
Code Word ◽  
Geometric Constraints ◽  
Fringe Projection ◽  
Average Intensity ◽  
Fringe Order ◽  
Projection System ◽  
Absolute Phase ◽  
Three Phase

Fringe projection technologies have been widely used for three-dimensional (3D) shape measurement. One of the critical issues is absolute phase recovery, especially for measuring multiple isolated objects. This paper proposes a method for absolute phase retrieval using only one coded pattern. A total of four patterns including one coded pattern and three phase-shift patterns are projected, captured, and processed. The wrapped phase, as well as average intensity and intensity modulation, are calculated from three phase-shift patterns. A code word encrypted into the coded pattern can be calculated using the average intensity and intensity modulation. Based on geometric constraints of fringe projection system, the minimum fringe order map can be created, upon which the fringe order can be calculated from the code word. Compared with the conventional method, the measurement depth range is significantly improved. Finally, the wrapped phase can be unwrapped for absolute phase map. Since only four patterns are required, the proposed method is suitable for real-time measurement. Simulations and experiments have been conducted, and their results have verified the proposed method.

scholarly journals New Pulse Width Modulation Technique to Reduce Losses for Three-Phase Photovoltaic Inverters

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mohannad Jabbar Mnati ◽  
Dimitar V. Bozalakov ◽  
Alex Van den Bossche
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Photovoltaic System ◽  
Pv System ◽  
Total Cost ◽  
Switching Losses ◽  
Three Phase ◽  
Operational Lifetime ◽  
Term Energy ◽  
Dc Bus

Nowadays, most three-phase, “off the shelf” inverters use electrolytic capacitors at the DC bus to provide short term energy storage. However, this has a direct impact on inverter lifetime and the total cost of the photovoltaic system. This article proposes a novel control strategy called a 120° bus clamped PWM (120BCM). The 120BCM modulates the DC bus and uses a smaller DC bus capacitor value, which is typical for film capacitors. Hence, the inverter lifetime can be increased up to the operational lifetime of the photovoltaic panels. Thus, the total cost of ownership of the PV system will decrease significantly. Furthermore, the proposed 120BCM control strategy modulates only one phase current at a time by using only one leg to perform the modulation. As a result, switching losses are significantly reduced. The full system setup is designed and presented in this paper with some practical results.

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