Pulse width modulation type audio amplifier having variable average switching frequency

2005 ◽  
Vol 118 (4) ◽  
pp. 2104
Author(s):  
Yong Hun Cho ◽  
Bong Joo Kim
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Switching Frequency ◽  
Audio Amplifier ◽  
Modulation Type

A Novel Soft Switching Based Fuzzy Logic Control for Single Phase Inverter

2014 ◽  
Vol 573 ◽  
pp. 143-149
Author(s):  
N. Ismayil Kani ◽  
B.V. Manikandan ◽  
Prabakar Perciyal
Keyword(s):  
Fuzzy Logic ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Soft Switching ◽  
Switching Frequency ◽  
Pwm Inverter ◽  
Zero Voltage Switching ◽  
Control Scheme ◽  
Zero Voltage ◽  
Voltage Switching

—This The Pulse Width Modulation (PWM) DC-to-AC inverter has been widely used in many applications due to its circuit simplicity and rugged control scheme. It is however driven by a hard-switching pulse width modulation (PWM) inverter, which has low switching frequency, high switching loss, high electro-magnetic interference (EMI), high acoustic noise and low efficiency, etc. To solve these problems of the hard-switching inverter, many soft-switching inverters have been designed in the past. Unfortunately, high device voltage stress, large dc link voltage ripples, complex control scheme and so on are noticed in the existing soft-switching inverters. This proposed work overcomes the above problems with simple circuit topology and all switches work in zero-voltage switching condition. Comparative analysis between conventional open loop, PI and fuzzy logic based soft switching inverter is also presented and discussed. Keywords—Zero voltage switching, Inverter, Dc link, PI controller, Fuzzy logic system control ,Modulation strategy, Soft switching

scholarly journals A Novel Filter Extracted Equivalent Control Based Fixed Frequency Sliding Mode Approach for Power Electronic Converters

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 853 ◽  
Author(s):  
Abdul Yasin ◽  
Muhammad Ashraf ◽  
Aamer Bhatti
Keyword(s):  
Boundary Layer ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Sliding Mode ◽  
Discontinuous Function ◽  
Switching Frequency ◽  
Power Electronic ◽  
Power Electronic Converters ◽  
Fixed Frequency ◽  
Equivalent Control

The key issue in the implementation of the Sliding Mode Control (SMC) in analogue circuits and power electronic converters is its variable switching frequency. The drifting frequency causes electromagnetic compatibility issues and also adversely affect the efficiency of the converter, because the proper size of the inductor and the capacitor depends upon the switching frequency. Pulse Width Modulation based SMC (PWM-SMC) offers the solution, however, it uses either boundary layer approach or employs pulse width modulation of the ideal equivalent control signal. The first technique compromises the performance within the boundary layer, while the latter may not possess properties like robustness and order reduction due to the absence of the discontinuous function. In this research, a novel approach to fix the switching frequency in SMC is proposed, that employs a low pass filter to extract the equivalent control from the discontinuous function, such that the performance and robustness remains intact. To benchmark the experimental observations, a comparison with existing double integral type PWM-SMC is also presented. The results confirm that an improvement of 20% in the rise time and 25.3% in the settling time is obtained. The voltage sag during step change in load is reduced to 42.86%, indicating the increase in the robustness. The experiments prove the hypothesis that a discontinuous function based fixed frequency SMC performs better in terms of disturbances rejection as compared to its counterpart based solely on ideal equivalent control.

Modelling and analysis of a high-performance Class D audio amplifier using unipolar pulse-width-modulation

2012 ◽  
Vol 99 (2) ◽  
pp. 163-177 ◽  
Author(s):  
Zekun Zhou ◽  
Yue Shi ◽  
Xin Ming ◽  
Bo Zhang ◽  
Zhaoji Li ◽  
...  
Keyword(s):  
Pulse Width ◽  
High Performance ◽  
Pulse Width Modulation ◽  
Audio Amplifier ◽  
Class D ◽  
Unipolar Pulse

Synchronized Symmetrical Bus-Clamping PWM Strategies for Three Level Inverter: Applications to Low Switching Frequencies

2011 ◽  
Vol 12 (2) ◽  
Author(s):  
Sreenivasappa Bhupasandra Veeranna ◽  
Udaykumar R Yaragatti ◽  
Abdul R Beig
Keyword(s):  
Pulse Width ◽  
Output Voltage ◽  
High Performance ◽  
Pulse Width Modulation ◽  
Industrial Applications ◽  
Voltage Source ◽  
Switching Frequency ◽  
Space Vector ◽  
Digital Implementation ◽  
Switching Losses

The digital control of three-level voltage source inverter fed high power high performance ac drives has recently become a popular in industrial applications. In order to control such drives, the pulse width modulation algorithm needs to be implemented in the controller. In this paper, synchronized symmetrical bus-clamping pulse width modulation strategies are presented. These strategies have some practical advantages such as reduced average switching frequency, easy digital implementation, reduced switching losses and improved output voltage quality compared to conventional space vector pulse width modulation strategies. The operation of three level inverter in linear region is extended to overmodulation region. The performance is analyzed in terms THD and fundamental output voltage waveforms and is compared with conventional space vector PWM strategies and found that switching losses can be minimized using bus-clamping strategy compared to conventional space vector strategy. The proposed method is implemented using Motorola Power PC 8240 processor and verified on a constant v/f induction motor drive fed from IGBT based inverter.

scholarly journals A Zero-Voltage-Transition Interleaved Boost Converter and Its Application to PFC

2011 ◽  
Vol 2011 ◽  
pp. 1-10 ◽  
Author(s):  
Lúcio dos Reis Barbosa
Keyword(s):  
Conversion Efficiency ◽  
Power Factor ◽  
Pulse Width ◽  
Pulse Width Modulation ◽  
Power Factor Correction ◽  
Switching Frequency ◽  
High Conversion Efficiency ◽  
Interleaved Boost Converter ◽  
Efficient Power ◽  
Zero Voltage

An efficient power factor correction converter is presented. Two boost-topology switching cells are interleaved to minimize EMI while operating at lower switching frequency and soft switching to minimize losses. The result is a system with high conversion efficiency, able to operate in a pulse-width-modulation (PWM) way. Seven transition states of the ZVT converter in one switching period are described. In order to illustrate the operational principle key, implementation details, including simulations, are described. The validity of this converter is guaranteed by the obtained results.

scholarly journals Multioutput Flyback DC-DC Converter for MIL Applications

2021 ◽  
Author(s):  
Sukumar Patil ◽  
Bhanuprakash CV ◽  
Bhoopendrakumar Singh
Keyword(s):  
Pulse Width ◽  
Pulse Width Modulation ◽  
Short Circuit ◽  
Current Mode ◽  
Switching Frequency ◽  
Current Output ◽  
Military Applications ◽  
Input Range ◽  
Emi Filter ◽  
Load Conditions

Abstract This paperwork explains the design and development of isolated triple output dc-dc converter for military applications. Converter has designed with flyback topology with opto-coupler based feedback for regulated main output and regulators are used to provide another two outputs. It is realized with switching frequency of 190KHz (internal free run frequency) and can be able to operate up to 210KHz with external synchronization. LTM46xx micro-modules are used as buck regulators to provide required lower output voltages. Current mode pulse width modulation controller IC is used to drive the MOSFET switch. It has following features like inbuilt EMI filter, external inhibit function, external synchronization capability, input under voltage and over voltage protection, primary side over current, output over current and short circuit protection. Converter is designed to operate for wide input range from 18V to 36V with efficiency of more than 75% in full load conditions.

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