EMI Reduction of PFC Rectifier and LLC Converter with Automatic Output Ripple Improvement

2020 ◽  
Vol 38 ◽  
pp. 103-117
Author(s):  
Yasunori Kobori ◽  
Noriyuki Oiwa ◽  
Shogo Katayama ◽  
Ahmad Bustoni ◽  
Yi Fei Sun ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Power Factor ◽  
Output Voltage ◽  
Clock Pulse ◽  
Operating Frequency ◽  
Duty Ratio ◽  
Clock Frequency ◽  
Forward Converter ◽  
Electro Magnetic ◽  
Emi Reduction

This paper proposes the method of the Electro-Magnetic Interference (EMI) noise reduction of the AC-DC rectifiers and the DC-DC converters with the insulated transformers. For the Power Factor Correction (PFC) rectifier, the power factor is the most important item, but the EMI noise emitted from the clock pulse is not remarked. For the DC-DC converters such as the forward converter, the efficiency is the most important. We have focused on the EMI noise reduction for the PFC rectifier and insulated DC-DC converters with the frequency modulation of the clock pulses. First, the spectrum level of the clock pulse is introduced to be much reduced by shaking the clock frequency for the PFC rectifier and the forward converter. Next, we have investigated the EMI reduction of the LLC converter whose operating frequency varies to make the output voltage stable. It is difficult to modify the operating frequency to reduce the EMI noise. We have investigated to reduce the EMI noise by shaking the duty ratio of the resonant signals for the LLC converter. In this case, the output voltage ripple is increased by much EMI noise reduction. Finally, the technology to stabilize the increased ripple is introduced.

Frequency Stabilization and EMI Noise Reduction of COT Method Ripple-Controlled Switching Converters with Output Voltage Ripple Cancellation

2020 ◽  
Vol 38 ◽  
pp. 130-142
Author(s):  
Yasunori Kobori ◽  
Yi Fei Sun ◽  
Minh Tri Tran ◽  
Anna Kuwana ◽  
Haruo Kobayashi
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
Peak Level ◽  
Operating Frequency ◽  
Duty Ratio ◽  
Switching Converters ◽  
Clock Frequency ◽  
Voltage Ripple ◽  
Ripple Cancellation ◽  
Emi Reduction

This paper proposes a new EMI reduction and automatic ripple cancellation technique about the ripple-controlled converter with the ripple injection and Constant-On Time (COT) method. The ripple-controlled converters have no stable clock and it is difficult to reduce the EMI noise by shaking the operating frequency. The new method of EMI reduction is that the COT pulse width is modulated by the triangular signal so that the operating frequency is modulated and the spectrum peak level of the clock frequency is greatly reduced. But the output voltage ripple is much increased because of the change of the duty ratio of the operating frequency. The increaced ripple is canceled by adding the modulation signal to the ripple injection circuit. Moreover stabiliztion of the operating frequency on Discontinuous Conduction Mode (DCM) is reported. The operating frequency falls down on DCM mode in the COT converters. To stabilize the operating frequency, cheking the operating period is fedback to control the COT pulse width

scholarly journals Robust Digital Control for Interleaved PFC Boost Converter Using Approximate 2DOF

1970 ◽  
Vol 8 (2) ◽  
pp. 187-194
Author(s):  
Yuki Satake ◽  
Hiroyuki Furuya ◽  
Yohei Mochizuki ◽  
Yuji Fukaishi ◽  
Kohji Higuchi ◽  
...  
Keyword(s):  
Power Factor ◽  
Output Voltage ◽  
Sudden Change ◽  
Experimental Studies ◽  
Input Voltage ◽  
Boost Converter ◽  
Buck Converter ◽  
Digital Controller ◽  
Step Response ◽  
Duty Ratio

In recent years, improving of power factor and reducing harmonic distortion in electrical instruments are needed. In general, a current conduction mode boost converter is used for active PFC (Power Factor Correction). In a PFC boost converter, if a duty ratio, a load resistance and an input voltage are changed, the dynamic characteristics are varied greatly. This is the prime reason of difficulty of controlling the interleaved PFC boost converter. In this paper, a robust digital controller for suppressing the change of step response characteristics and variation of output voltage at a DC-DC buck converter load sudden change with high power factor and low harmonic is proposed. Experimental studies using a micro-processor for controller demonstrate that the proposed digital controller is effective to improve power factor and to suppress output voltage variation.

An Improved Z-Source Boost-Buck Rectifier Topology with Lower DC Output Voltage

2011 ◽  
Vol 383-390 ◽  
pp. 2145-2150
Author(s):  
Jian Shang ◽  
Zhi Zhen Liu ◽  
Yan Zhang ◽  
Si Hao Duan
Keyword(s):  
Power Factor ◽  
Output Voltage ◽  
Power Factor Correction ◽  
Modulation Index ◽  
Voltage Source ◽  
Duty Ratio ◽  
Harmonic Current ◽  
Simulation Results ◽  
Boost Rectifier

A Z-source boost-buck rectifier topology has been proposed to overcome the limitation of the conventional voltage source rectifier which is a boost rectifier. Conventional Z-source rectifier topology’s lowest dc output voltage is limited because increasing the shoot-through duty ratio and the modulation index simultaneously to obtain low dc output voltage is contradictory with the principle that the sum of M and D must be lower than 1. To overcome this contradiction, this paper proposes a novel topology for Z-source rectifier which can obtain lower dc output voltage with power factor correction and less input harmonic current. This paper firstly analyzes the proposed topology and makes a comparison with the conventional one. At last, the simulation results will be presented and verify its outstanding buck capability.

EMI Noise Reduction of DC-DC Switching Converters with Automatic Output Ripple Cancellation

2020 ◽  
Vol 38 ◽  
pp. 157-170
Author(s):  
Yasunori Kobori ◽  
Yi Fei Sun ◽  
Minh Tri Tran ◽  
Anna Kuwana ◽  
Haruo Kobayashi
Keyword(s):  
Noise Reduction ◽  
Output Voltage ◽  
Current Mode ◽  
Buck Converter ◽  
Operating Frequency ◽  
Switching Converters ◽  
Stable Level ◽  
Voltage Mode ◽  
Voltage Ripple ◽  
Ripple Cancellation

This paper proposes new EMI reduction technologies and automatic output voltage ripple cancellation method for the PWM buck converter with voltage-mode or current-mode and the ripple-controlled converters. Genenrally, modfying the clock frequeny is effective to reduce the EMI noise, but it may increase the output ripple substantially. We have developed techniques to cancel the increased ripple by modifying the slope of the saw-tooth signal or current of the ripple injection circuit. The EMI spectrum of the operating frequency is reduced by more than 15dB and the modified large ripple is canceled to the stable level.

An Online No-Break With Power Factor Correction and Output Voltage Stabilization

2005 ◽  
Vol 20 (5) ◽  
pp. 1109-1117 ◽  
Author(s):  
V.M. Pacheco ◽  
L.C. de Freitas ◽  
J.B. Vieira ◽  
A.A. Pereira ◽  
E.A.A. Coelho ◽  
...  
Keyword(s):  
Power Factor ◽  
Output Voltage ◽  
Power Factor Correction ◽  
Voltage Stabilization

The Three-Level Sine-Wave Inverter with Power Factor Correction (PFC)

2015 ◽  
Vol 781 ◽  
pp. 402-405
Author(s):  
Napat Krachangchaeng ◽  
Sakorn Po-Ngam
Keyword(s):  
Power Factor ◽  
Output Voltage ◽  
Power Factor Correction ◽  
Sine Wave ◽  
Input Power ◽  
Small Current ◽  
Uninterruptible Power Supply ◽  
Current Harmonics ◽  
Electric Device ◽  
Uninterruptible Power

Nowadays, the uninterruptible power supply (UPS) is important in reliability for electric device. The UPS need high quality electricity. Therefore, the simulation of the three-level sine-wave inverter with power factor correction (PFC) is proposed in this paper. Moreover, the circuit’s guidelines of the active PFC controller in the active PFC and the sinusoidal output voltage are also presented. Validity of the proposed the three-level sine-wave inverter with the active PFC is confirmed by simulation. The simulation results show the very small current harmonics, the input power factor most nearly unity and constant output voltage when the suddenly step-load changed.

scholarly journals Mathematical modeling and control of wind energy electric conversion system feeding standalone load

2017 ◽  
Vol 7 (1.2) ◽  
pp. 47
Author(s):  
N K Rayaguru ◽  
N. Poornachandra Rao ◽  
K. Navin Sam ◽  
Sunil Kumar Thakur
Keyword(s):  
Wind Energy ◽  
State Space ◽  
Output Voltage ◽  
State Space Model ◽  
Synchronous Generator ◽  
Boost Converter ◽  
Duty Ratio ◽  
Space Model ◽  
Conversion System ◽  
Constant Output

In this paper, state space model of the complete Wind Energy Electric Conversion System (WEECS) comprising of wind turbine, Permanent Magnet Synchronous Generator (PMSG), uncontrolled rectifier, DC-DC boost converter, and SPWM inverter feeding a standalone load has been formulated. The derived state space model is then simulated using Matlab/Simulink to test the model. As the standalone three phase load connected to the inverter demands constant output voltage irrespective of intermittent wind pattern, a PI controller is used to control the duty ratio of DC-DC boost converter to maintain constant output voltage at the inverter end.

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