Linear Quadratic Gaussian Optimal Controlled Two-Stage Inverter for a High-Frequency AC Distribution Power System

2011 ◽  
Vol 230-232 ◽  
pp. 1287-1292
Author(s):  
Wei Liu ◽  
Zhi Gang Huang ◽  
Zhong Ning Guo
Keyword(s):  
High Frequency ◽  
Fast Response ◽  
Power Converter ◽  
System Stability ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Two Stage ◽  
Input Line ◽  
Uncertainty Model ◽  
Wide Range

The linear quadratic Gaussian Optimal control of a two-stage HFAC inverter system has been investigated in this paper. The uncertainty model of the high frequency resonant inverter is developed and analyzed with the input line and load variations taken into design considerations. The proposed control scheme has the advantages of fast response for both input line and load perturbations. It also ensures a wide range of system stability and guarantees robustness of the power converter. Both simulations and experimental results are provided to verify with the theoretical analysis through an experimental prototype with an output power of 500-W operating at 10 KHz and an output voltage of 24 V (peak value).

scholarly journals Optimal Modulation Techniques of a DAB Based Isolated Bidirectional Single-stage Single-phase AC-DC Converter

2021 ◽  
Author(s):  
Dibakar Das ◽  
Kaushik Basu ◽  
Sayan Paul
Keyword(s):  
High Frequency ◽  
Power Flow ◽  
Degrees Of Freedom ◽  
Single Phase ◽  
Single Stage ◽  
Switching Frequency ◽  
Switching Loss ◽  
Two Stage ◽  
Wide Range ◽  
Bidirectional Power Flow

A bidirectional single-phase AC to DC converter with high-frequency isolation finds a wide range of applications, including charging electric vehicles in the vehicle to grid applications. A conventional two-stage solution, where an AC-DC front-end rectifier is connected to an isolated DC-DC converter, suffers from poor efficiency due to hard switching of the AC-DC stage and poor reliability due to the existence of an electrolytic capacitance at the interstage DC link. A Dual Active Bridge (DAB) based single-stage AC-DC converter with a potential of bidirectional power flow can overcome the problems of a two stage solution. A rich literature exists in search for finding an efficient modulation strategy for this converter. This paper presents two constant switching frequency modulation strategies that support bidirectional power flow at any power factor utilizing all three degrees of freedom in modulation, also known as triple phase-shift modulation (TPS). One of the strategies minimizes RMS high-frequency transformer current over the line cycle, and the other one optimizes peak current. Hence, the conduction loss and the component stress over the entire line cycle are minimized. ZVS conditions are met for all high-frequency switching devices for the whole operating region, while the AC side converter is line frequency switched, incurring negligible switching loss. AC line current waveforms are of high quality and free from low-frequency harmonics. UPF operation is of importance for single-phase power conversion. All possible modes that the converter will experience over a line cycle for UPF operation are elaborated through detailed analysis. The proposed strategies are validated through experiment and simulation with 230 V, 50 Hz AC grid, 400 V DC, UPF, and output power of 1.2 kW.

Choosing an optimal β factor for relaxed eddy accumulation applications across vegetated and non-vegetated surfaces

2021 ◽  
Author(s):  
Teresa Vogl ◽  
Amy Hrdina ◽  
Christoph K. Thomas
Keyword(s):  
High Frequency ◽  
Fast Response ◽  
Optimal Choice ◽  
Meteorological Conditions ◽  
Forest Site ◽  
Dry Valleys ◽  
Measured Concentration ◽  
Concentration Difference ◽  
Relaxed Eddy Accumulation ◽  
Wide Range

<p>Understanding the source and transport behavior of atmospheric trace gases is important to better quantify, predict, and mitigate anthropogenic effects on the environment and climate. The relaxed eddy accumulation (REA) method enables measuring the fluxes of atmospheric compounds for which fast-response sensors are not available. In REA applications, air is sampled depending on the direction of the vertical wind w, into a reservoir for updrafts, and a reservoir for downdrafts, respectively. Deadbands are used to select only certain turbulent motions during sampling to obtain the concentration difference. The <em>β</em> factor is used to scale the measured concentration difference between both reservoirs to the flux.</p> <p>In this study, we evaluated a variety of different REA approaches with the goal of formulating recommendations applicable over a wide range of surfaces and meteorological conditions for an optimal choice of the <em>β</em> factor in combination with a suitable deadband. Observations with fast-response sensors were collected in three contrasting ecosystems offering stark differences in scalar transport and dynamics: a mid-latitude grassland ecosystem in Europe (Lindenberg, Germany), a loose gravel surface of the Dry Valleys of Antarctica, and a spruce forest site in the European mid-range mountains (Waldstein, Germany). REA applications were simulated using the high-frequency observations.</p>

Unified Controller Design for Two-Stage Converter Based on Feed-Forward Compensation

2013 ◽  
Vol 732-733 ◽  
pp. 1271-1279
Author(s):  
Tao Xia ◽  
Zhi Chang Yuan ◽  
Yong Xing Li ◽  
Hai Feng Guo ◽  
Bai Hua Zhang
Keyword(s):  
Control Structure ◽  
Controller Design ◽  
Fast Response ◽  
Power Converter ◽  
Two Stage ◽  
Feed Forward ◽  
Modeling Process ◽  
Power Change ◽  
Bus Voltage ◽  
Steady State Performance

A unified control structure for two-stage power converter system (PCS) is proposed which incorporates both charging and discharging modes within the same controller. Detailed modeling process is presented using sub-system approach. Power feed-forward compensation with direct battery current reference is engaged to enable fast response to power change on battery side, thus reducing DC bus voltage fluctuation during transients. Simulation and experiments show that the proposed control structure can effectively improve dynamic response without compromising steady-state performance.

scholarly journals Optimal Modulation Techniques of a DAB Based Isolated Bidirectional Single-stage Single-phase AC-DC Converter

2021 ◽  
Author(s):  
Dibakar Das ◽  
Kaushik Basu ◽  
Sayan Paul
Keyword(s):  
High Frequency ◽  
Power Flow ◽  
Degrees Of Freedom ◽  
Single Phase ◽  
Single Stage ◽  
Switching Frequency ◽  
Switching Loss ◽  
Two Stage ◽  
Wide Range ◽  
Bidirectional Power Flow

A bidirectional single-phase AC to DC converter with high-frequency isolation finds a wide range of applications, including charging electric vehicles in the vehicle to grid applications. A conventional two-stage solution, where an AC-DC front-end rectifier is connected to an isolated DC-DC converter, suffers from poor efficiency due to hard switching of the AC-DC stage and poor reliability due to the existence of an electrolytic capacitance at the interstage DC link. A Dual Active Bridge (DAB) based single-stage AC-DC converter with a potential of bidirectional power flow can overcome the problems of a two stage solution. A rich literature exists in search for finding an efficient modulation strategy for this converter. This paper presents two constant switching frequency modulation strategies that support bidirectional power flow at any power factor utilizing all three degrees of freedom in modulation, also known as triple phase-shift modulation (TPS). One of the strategies minimizes RMS high-frequency transformer current over the line cycle, and the other one optimizes peak current. Hence, the conduction loss and the component stress over the entire line cycle are minimized. ZVS conditions are met for all high-frequency switching devices for the whole operating region, while the AC side converter is line frequency switched, incurring negligible switching loss. AC line current waveforms are of high quality and free from low-frequency harmonics. UPF operation is of importance for single-phase power conversion. All possible modes that the converter will experience over a line cycle for UPF operation are elaborated through detailed analysis. The proposed strategies are validated through experiment and simulation with 230 V, 50 Hz AC grid, 400 V DC, UPF, and output power of 1.2 kW.

Analysis and Design of 3.3 kV IGBT Based Three-Level DC/DC Converter with High-Frequency Isolation and Current Doubler Rectifier

2009 ◽  
Vol 25 (25) ◽  
pp. 103-108
Author(s):  
Dmitri Vinnikov ◽  
Tanel Jalakas ◽  
Indrek Roasto
Keyword(s):  
High Voltage ◽  
High Frequency ◽  
Power Converter ◽  
Rolling Stock ◽  
Analysis And Design ◽  
Auxiliary Power ◽  
Igbt Modules ◽  
Isolation Transformer ◽  
New Generation ◽  
Generation Power

Analysis and Design of 3.3 kV IGBT Based Three-Level DC/DC Converter with High-Frequency Isolation and Current Doubler RectifierThe paper presents the findings of a R&D project connected to the development of auxiliary power supply (APS) for the high-voltage DC-fed rolling stock applications. The aim was to design a new-generation power converter utilizing high-voltage IGBT modules, which can outpace the predecessors in terms of power density, i.e. to provide more power for smaller volumetric space. The topology proposed is 3.3 kV IGBT-based three-level neutral point clamped (NPC) half-bridge with high-frequency isolation transformer and current doubler rectifier that fulfils all the targets imposed by the designers. Despite an increased component count the proposed converter is very simple in design and operation. The paper provides an overview of the design with several recommendations and guidelines. Moreover, the simulation and experimental results are discussed and the performance evaluation of the proposed converter is presented.

Sign in / Sign up

Export Citation Format

Share Document