scholarly journals Analysis of Non-Minimum Phase System for AC/DC Battery Charger Power Factor Correction Converter

2022 ◽  
Vol 12 (2) ◽  
pp. 868
Author(s):  
Mahmoud Nassary ◽  
Enric Vidal-Idiarte ◽  
Javier Calvente
Keyword(s):  
Power Factor ◽  
Output Voltage ◽  
Transfer Functions ◽  
Dynamic Performance ◽  
Harmonic Distortion ◽  
Phase System ◽  
Minimum Phase ◽  
Input Output ◽  
Voltage Range ◽  
Battery Chargers

Electric mobility is nowadays one of the more important trends regarding pollution reduction and global warming due to fuel consumption. Big efforts are done in order to develop efficient and reliable power electronic systems for electric vehicles. In two stage on board-battery chargers, one way of improving efficiency is by means of ensuring the DC-DC isolated converter always operates in the nominal input/output voltage ratio, that could be achieved with a variable DC-link operation. In this paper, a four-switch buck-boost based AC/DC converter is deeply analyzed in order to improve its dynamic performance, the power factor and the total harmonic distortion. The converter suffers from a non-minimum phase characteristic in different input–output transfer functions, which reduces the closed-loop bandwidth of the system. Therefore, after a deep converter analysis has been done, different solutions have been evaluated and tested. Finally, a control to different output transfer functions of the converter become minimum phase, which allows us to increase the system bandwidth and, consequently, high power factor, low harmonics distortion, single control structure and fast dynamics for wide output voltage range are achieved.

scholarly journals On the Relation between Mains-Side Current THD and DC Link Voltage Loop Gain in Grid-Connected Unity Power Factor Operating Converters

2021 ◽  
Author(s):  
Alon Kuperman
Keyword(s):  
Power Factor ◽  
Dynamic Performance ◽  
Harmonic Distortion ◽  
Loop Gain ◽  
Unity Power Factor ◽  
Trade Off ◽  
Loop Bandwidth ◽  
Grid Connected Converters ◽  
Grid Side ◽  
Double Grid

<p>It is well-known that attainable DC link voltage loop bandwidth in grid-connected converters operating with unity power factor is limited due to trade-off with AC-side current total harmonic distortion (THD). The letter reveals that THD requirement directly imposes the value of voltage loop gain magnitude at double-grid frequency; therefore the dynamic performance may be improved without deteriorating the grid-side current quality by modifying the controller structure such that the loop gain magnitude at double-grid frequency and the crossover frequency are decoupled. Experimental results validate the revealed findings.</p>

scholarly journals High-efficiency Bidirectional Buck–Boost Converter for Residential Energy Storage System

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3786 ◽  
Author(s):  
Seok-Hyeong Ham ◽  
Yoon-Geol Choi ◽  
Hyeon-Seok Lee ◽  
Sang-Won Lee ◽  
Su-Chang Lee ◽  
...  
Keyword(s):  
Energy Storage ◽  
Output Voltage ◽  
High Efficiency ◽  
Storage System ◽  
Core Loss ◽  
Input Voltage ◽  
Switching Frequency ◽  
Input Output ◽  
Voltage Range ◽  
Output Filter

This paper proposes a bidirectional dc–dc converter for residential micro-grid applications. The proposed converter can operate over an input voltage range that overlaps the output voltage range. This converter uses two snubber capacitors to reduce the switch turn-off losses, a dc-blocking capacitor to reduce the input/output filter size, and a 1:1 transformer to reduce core loss. The windings of the transformer are connected in parallel and in reverse-coupled configuration to suppress magnetic flux swing in the core. Zero-voltage turn-on of the switch is achieved by operating the converter in discontinuous conduction mode. The experimental converter was designed to operate at a switching frequency of 40–210 kHz, an input voltage of 48 V, an output voltage of 36–60 V, and an output power of 50–500 W. The power conversion efficiency for boost conversion to 60 V was ≥98.3% in the entire power range. The efficiency for buck conversion to 36 V was ≥98.4% in the entire power range. The output voltage ripple at full load was <3.59 Vp.p for boost conversion (60 V) and 1.35 Vp.p for buck conversion (36 V) with the reduced input/output filter. The experimental results indicate that the proposed converter is well-suited to smart-grid energy storage systems that require high efficiency, small size, and overlapping input and output voltage ranges.

Control Strategies for Wide Output Voltage Range LLC Resonant DC–DC Converters in Battery Chargers

2014 ◽  
Vol 63 (3) ◽  
pp. 1117-1125 ◽  
Author(s):  
Fariborz Musavi ◽  
Marian Craciun ◽  
Deepak S. Gautam ◽  
Wilson Eberle
Keyword(s):  
Output Voltage ◽  
Control Strategies ◽  
Voltage Range ◽  
Battery Chargers

scholarly journals Improvement of Power Factor by Input Filter and Ripple Reduction using Cuk Converter in Continuous Conduction Mode

2019 ◽  
Vol 8 (6) ◽  
pp. 4938-4945
Keyword(s):  
Power Factor ◽  
Closed Loop ◽  
Harmonic Distortion ◽  
Distortion Factor ◽  
Cuk Converter ◽  
Battery Chargers ◽  
Input Filter ◽  
Ripple Reduction ◽  
Source Current ◽  
Sinusoidal Shape

The basic Converters like buck, boost and buckboost provide pulsed ripple currents either on input or output sides. A Cuk Converter has inductors on both input and output sides, thus produces continuous currents with reduced ripple. By extending the Cuk Converter to AC side with the support of additional rectifier circuit the power factor can be assessed. The significant concerns when utilizing DC-DC converters with AC source is large Total Harmonic Distortion (THD) and low power factor. A properly designed filter circuit on AC side reduces THD and improves the power factor. In this paper a Cuk Converter (CC) topology with rectifier and inductive. capacitive. inductive (LCL) filter is proposed to reduce THD and improve the power factor. The CC circuit is designed and analyzed to reduce ripple content of currents. The reduction in ripple on DC side in turn improves the sinusoidal shape of current on AC source side. The closed loop simulation of the proposed circuit is carried out using a systematically derived type III compensator. The proposed circuit is practically validated in closed loop using FPGA controller to confirm the simulated waveforms. The results substantiate the fact that the proposed circuit shrinks ripple on DC source side and reduces harmonics of AC source current. The reduction in harmonics decreases THD to a large extent and improves distortion factor, which enhances the power factor. Also the reduction in ripple trims down losses in the circuit and improves the output power, thus suitable for DC to DC conversions in power supplies for viz. electric vehicles, computers, battery chargers and televisions. The improvement in power factor reduces the power drawn from the source and hence the efficiency of the system is improved.

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