A phase lagging compensation for output current of DCM flyback based PV micro-inverters

Author(s):  
Young-Hyok Ji ◽  
Doo-Yong Jung ◽  
Jun-Gu Kim ◽  
Young-Ho Kim ◽  
Chung-Yuen Won
Keyword(s):  
2019 ◽  
Vol 139 (9) ◽  
pp. 806-813 ◽  
Author(s):  
Mitsuhiro Kadota ◽  
Hiroyuki Shoji ◽  
Atsushi Hatakeyama ◽  
Keiji Wada

2019 ◽  
pp. 56-61
Author(s):  
Huang ChunXiang ◽  
Henadiy Pavlov ◽  
Mykhailo Pokrovskyi ◽  
Andriy Obrubov ◽  
Iryna Vinnychenko

The research object is the electromagnetic processes in the semiconductor power converters based on the schemes with circuit commutation and containing resonant circuits of reactive elements and transformers with a small coupling coefficient. The research aim is to develop a technology for a fast wireless battery charging for the use in clean energy vehicles, which would be based on a resonant converter with a pulse-count adjustment with a phase shift control. The latter provides a high energy performance in a wide range of regulation and a low sensitivity to changes in the magnetic system parameters. This is a final report. The report presents the results of the work performed in accordance with the Terms of Reference for the second stage of the scientific and research work. The following theoretical problems have been solved: development of a mathematical model of a series resonant converter with a pulse-count adjustment for contactless inductive energy transmission, which provided a high accuracy for the studies of the electromagnetic processes in the power section of multi-circuit resonant converters for contactless energy transmission, as well as an opportunity to assess the energy parameters of multi-circuit converters at pulse-count adjustment; compilation of mathematical dependencies of the average input and output current values on the number of half-cycles of resonant oscillations during energy transmission to the circuit and energy dissipation, the supply voltage and the resonant circuit’s parameters, which allowed assessing the converter’s energy parameters over a wide control range; compilation of the dependencies of the converter’s output power and coefficient of efficiency on the number of halfcycles of resonant oscillations during energy transmission to the circuit and energy dissipation, on supply voltage and on the resonant circuit’s parameters, which made it possible to evaluate the efficiency of the pulse-count adjustment of resonant converters for contactless energy transmission; realization of a dynamic model of a resonant converter for contactless energy transmission in the form of transfer functions for small disturbances caused by fluctuations in supply voltage, which made it possible to estimate the effect of its instability on the quality of output current stabilization.


Author(s):  
Zhe Zhao ◽  
Yaozheng Wang ◽  
Tengfei Sun ◽  
Yunjia Li ◽  
Lihua Tang ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
pp. 6
Author(s):  
Orazio Aiello

The paper deals with the immunity to Electromagnetic Interference (EMI) of the current source for Ultra-Low-Voltage Integrated Circuits (ICs). Based on the properties of IC building blocks, such as the current-splitter and current correlator, a novel current generator is conceived. The proposed solution is suitable to provide currents to ICs operating in the sub-threshold region even in the presence of an electromagnetic polluted environment. The immunity to EMI of the proposed solution is compared with that of a conventional current mirror and evaluated by analytic means and with reference to the 180 nm CMOS technology process. The analysis highlights how the proposed solution generates currents down to nano-ampere intrinsically robust to the Radio Frequency (RF) interference affecting the input of the current generator, differently to what happens to the output current of a conventional mirror under the same conditions.


Sensors ◽  
2021 ◽  
Vol 21 (11) ◽  
pp. 3596
Author(s):  
Chia-Ming Liang ◽  
Yi-Jen Lin ◽  
Jyun-You Chen ◽  
Guan-Ren Chen ◽  
Shih-Chin Yang

For pulse width modulation (PWM) inverter drives, an LC filter can cascade to a permanent magnet (PM) machine at inverter output to reduce PWM-reflected current harmonics. Because the LC filter causes resonance, the filter output current and voltage are required for the sensorless field-oriented control (FOC) drive. However, existing sensors and inverters are typically integrated inside commercial closed-form drives; it is not possible for these drives to obtain additional filter output signals. To resolve this integration issue, this paper proposes a sensorless LC filter state estimation using only the drive inside current sensors. The design principle of the LC filter is first introduced to remove PWM current harmonics. A dual-observer is then proposed to estimate the filter output current and voltage for the sensorless FOC drive. Compared to conventional model-based estimation, the proposed dual-observer demonstrates robust estimation performance under parameter error. The capacitor parameter error shows a negligible influence on the proposed observer estimation. The filter inductance error only affects the capacitor current estimation at high speed. The performance of the sensorless FOC drive using the proposed dual-observer is comparable to the same drive using external sensors for filter voltage and current measurement. All experiments are verified by a PM machine with only 130 μH phase inductance.


Energies ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 64
Author(s):  
Chien-Chun Huang ◽  
Yu-Chen Liu ◽  
Chia-Ching Lin ◽  
Chih-Yu Ni ◽  
Huang-Jen Chiu

To balance the cost and volume when applying a low output current ripple, the power supply design should be able to eliminate the current ripple under any duty cycle in medium and high switching frequencies, and considerably reduce filter volume to improve power density. A stacked buck converter was eventually selected after reviewing the existing solutions and discussing their advantages and disadvantages. A stacked buck converter is used as a basis to propose the transient response and output current ripple elimination effect, boundary limit control method, and low output ripple dead time modulation method to make individual improvements. The principle, mathematical derivation, small-signal model, and compensator design method of the improvement method are presented in detail. Moreover, simulation results are used to mutually verify the correctness and effectiveness of the improvement method. A stacked buck converter with 330-V input, 50-V output, and 1-kW output power was implemented to verify the effect of the low output current ripple dead time modulation. Experimental results showed that the peak-to-peak value of the output current ripple was reduced from 2.09 A to 559 mA, and the RMS value was reduced from 551 mA to 91 mA, thereby effectively improving the output current ripple.


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