Soft Switching in Switched Inertance Hydraulic Circuits

2016 ◽  
Author(s):  
Alexander C. Yudell ◽  
James D. Van de Ven
Keyword(s):  
High Speed ◽  
Soft Switching ◽  
Power Delivery ◽  
Lumped Parameter Model ◽  
Energy Losses ◽  
Hydraulic Systems ◽  
Zero Voltage Switching ◽  
Lumped Parameter ◽  
Capacitive Element ◽  
Zero Voltage

Switched Inertance Hydraulic Systems (SIHS) use inductive, capacitive, and switching elements to boost or buck a pressure from a source to a load in an ideally lossless manner. Real SIHS circuits suffer a variety of energy losses, with throttling of flow during transitions of the high-speed valve resulting in 44% of overall losses. These throttling energy losses can be mitigated by applying the analog of zero-voltage-switching, a soft switching strategy, adopted from power electronics. In the soft switching circuit, the flow that would otherwise be throttled across the transitioning valve is stored in a capacitive element and bypassed through check valves in parallel with the switching valves. To evaluate the effectiveness of soft switching in a boost converter SIHS, a lumped parameter model was constructed. The model demonstrates that soft switching can improve the efficiency of the circuit up to 42% and extend the power delivery capabilities of the circuit by 76%.

Soft Switching in Switched Inertance Hydraulic Circuits

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
Alexander C. Yudell ◽  
James D. Van de Ven
Keyword(s):  
High Speed ◽  
Peak Load ◽  
Soft Switching ◽  
Power Delivery ◽  
Lumped Parameter Model ◽  
Energy Losses ◽  
Hydraulic Systems ◽  
Zero Voltage Switching ◽  
Lumped Parameter ◽  
Capacitive Element

Switched inertance hydraulic systems (SIHS) use inductive, capacitive, and switching elements to boost or “buck” (reduce) a pressure from a source to a load in an ideally lossless manner. Real SIHS circuits suffer a variety of energy losses, with throttling of flow during transitions of the high-speed valve resulting in as much as 44% of overall losses. These throttling energy losses can be mitigated by applying the analog of zero-voltage-switching, a soft switching strategy, adopted from power electronics. In the soft switching circuit, the flow that would otherwise be throttled across the transitioning valve is stored in a capacitive element and bypassed through check valves in parallel with the switching valves. To evaluate the effectiveness of soft switching in a boost converter SIHS, a lumped parameter model was constructed. Simulation demonstrates that soft switching improves the efficiency of the modeled circuit by 42% at peak load power and extends the power delivery capabilities by 77%.

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 Control Strategy for Bidirectional Isolated 3-Phase Current-Fed Dual Active Bridge Converter

Electronics ◽  
2018 ◽  
Vol 7 (10) ◽  
pp. 214 ◽  
Author(s):  
Dong-Min Lee ◽  
Seung-Wook Hyun ◽  
Jin-Wook Kang ◽  
Yong-Su Noh ◽  
Chung-Yuen Won
Keyword(s):  
Pulse Width Modulation ◽  
Soft Switching ◽  
Zero Voltage Switching ◽  
Phase Current ◽  
Dual Active Bridge ◽  
Circulating Current ◽  
Operation Techniques ◽  
Simulation And Experiment ◽  
Output Capacitor ◽  
Zero Voltage

This paper examines the characteristics of the zero voltage switching (ZVS) and zero voltage transition (ZVT) soft-switching applied in the 3-phase current fed dual active bridge (3P-CFDAB) converter, which combines the advantages of the dual active bridge (DAB) converter and current-fed full bridge (CFFB) converter. When an active clamp circuit is added to the CFFB converter, the circuit configuration of the DAB converter is shown in part of the entire circuit. This allows the use of pulse width modulation (PWM) techniques which combine the PWM techniques of both the DAB converter and CFFB converter. The proposed converter performs both duty and phase control at the same time in order to reduce the circulating current and ripple current of the output capacitor, which are the disadvantages of the CFFB converter and DAB converter. In addition, the ZVS and ZVT soft switching areas were analyzed by means of the phase current and leakage inductor current in each transformers. To verify the principle and feasibility of the proposed operation techniques, a simulation and experiment were implemented with the 3P-CFDAB.

scholarly journals Optimization of Switching Loss of a DC-DC Boost Converter

2019 ◽  
Vol 8 (3) ◽  
pp. 3333-3339
Keyword(s):  
Slight Modification ◽  
Industrial Applications ◽  
Soft Switching ◽  
Optimum Level ◽  
Switching Loss ◽  
Improve Performance ◽  
Boost Converters ◽  
Zero Voltage Switching ◽  
Zero Voltage ◽  
Critical Investigation

The dc-dc boost converters are widely used in various power conversion applications because of their increase in demand both in domestic, commercial and industrial applications. The voltage boosting techniques include mostly combination of components such as inductors, capacitors, switches etc with their various configurations. The combination of these boosting components oriented in different configurations appears largely in literature, but refer the techniques of hard-switching of the semi-conductor devices. In order to meet the growing demand and to look into the aspect of better efficiency of these converters, the soft-switching of devices plays a prominent role, which lacks in literature. Though very few papers appear in literature as far as soft-switching is concerned, but the addition of more than one or two switches make the things uneasy and the researchers lack interest in it. Even though the conventional boost converters appear in various forms of topologies in literature, but it needs further critical investigation so far to minimise switching loss. The proposed topology, which is similar to the conventional topology with slight modification, gives lucid insight in fulfilling with partial soft-switching capability of circuits. The single switch is turned-off under zero-voltage switching (ZVS) and turned-on under partial hard-switched by proper designing of snubber components. The prominent components of the topology are designed at its optimum level to improve performance

scholarly journals Design and operation of closed-loop triple-deck buck-boost converter with high gain soft switching

2020 ◽  
Vol 11 (1) ◽  
pp. 523
Author(s):  
S. Narasimha ◽  
Surender Reddy Salkuti
Keyword(s):  
Closed Loop ◽  
High Gain ◽  
Pi Controller ◽  
Boost Converter ◽  
Vital Role ◽  
Soft Switching ◽  
Parallel Operation ◽  
Zero Voltage Switching ◽  
Switching Losses ◽  
Zero Voltage

<span>This paper presents the design and operation of three-stage buck-boost converter with high gain soft switching using closed loop proportional integral (PI) controller. The proposed converter is designed by arranging three identical buck-boost converters working in parallel. The converter units are connected to each other by an inductor as a bridge. This inductor plays a vital role in soft switching operation of converter by maintaining the voltage applied to switches at zero voltage at switching intervals, i.e., the zero-voltage switching (ZVS). The closed-loop system is designed by PI controller, and it maintains the output constant irrespective of changes in input, and the system becomes stable. The proposed converter is efficient in reducing switching losses, leading to improved converter efficiency. Due to parallel operation of three identical converters, the output voltage and input current contain fewer ripples than those of a single converter with same specifications. Proposed converter is more economical and reliable with simpler structure as it utilizes only two inductors as extra elements. The design and analysis of proposed circuit has been carried out in MATLAB Simulink by operating the circuit in various modes.</span>

scholarly journals Soft-Switching High Gain Step-Up DC/DC Converter without Auxiliary Switches

2019 ◽  
Vol 8 (12S) ◽  
pp. 633-636
Keyword(s):  
Theoretical Analysis ◽  
Power Flow ◽  
High Efficiency ◽  
Input Voltage ◽  
High Gain ◽  
Soft Switching ◽  
Zero Voltage Switching ◽  
Auxiliary Cell ◽  
Zero Voltage ◽  
Voltage Switching

This manuscript presents a novel high gain, high efficiency Soft-switching high step-up DC/DC converter for battery-operated vehicles. The high step-up converter can transfer the power flow from the small voltage to high voltage. The conventional two input inductor hard switched non-isolated DC-DC converter improved with an additional auxiliary cell to attain the Zero voltage switching, due to obtaining the softswitching the efficiency may improve and reduces the stress across the main switches. The isolated converters are used as a transformer to attain high gain, whereas in the proposed converter obtains the high gain without a transformer and contains the high efficiency in the step-up mode of operation. The main aim of the converter is to attain the Zero voltage switching without using any additional auxiliary switches. In this paper, the input voltage applied as 30V, and the obtained output voltage is fifteen times to the applied voltage, which is 450V and the output power 850W. This paper mainly presents the theoretical analysis of converter operation and the evaluation of the simulation results validated with the theoretical analysis.

scholarly journals An Interleaved DC/DC Converter with Soft-switching Characteristic and high Step-up Ratio

2020 ◽  
Vol 10 (6) ◽  
pp. 2167
Author(s):  
Yong-Nong Chang ◽  
Hung-Liang Cheng ◽  
Hau-Chen Yen ◽  
Chien-Hsuan Chang ◽  
Wei-Di Huang
Keyword(s):  
Conversion Efficiency ◽  
Operation Mode ◽  
Soft Switching ◽  
Switching Characteristic ◽  
Boost Converters ◽  
Zero Voltage Switching ◽  
Zero Current Switching ◽  
Zero Current ◽  
Current Ripples ◽  
Zero Voltage

This study presents a dc/dc converter featuring soft-switching characteristic, high conversion efficiency, and high step-up ratio. The proposed circuit is composed of two parallel-connected boost converters. Only one coupled inductor is used to replace inductors of the boost converters which are interleaved operated at discontinuous-conduction mode (DCM). The current ripples at the input and the output terminals are reduced due to the interleaved operation. By freewheeling the current of the coupled inductor to discharge the stored electric charges in the parasitic capacitors of the active switches, both active switches can fulfill zero-voltage switching on (ZVS). Owing to DCM operation, the freewheeling diodes can fulfill zero-current switching off (ZCS). Therefore, the power conversion efficiency is improved. The operation principle for each operation mode is analyzed in detail and design equations for the component parameters are provided in this report. Finally, a prototype 200 W 48–400 V converter was implemented and measured to demonstrate the effectiveness of the proposed circuit.

scholarly journals Evaluation of a Combustion-Based Mesoscale Thermal Actuator in Open and Closed Operating Cycles

Actuators ◽  
2019 ◽  
Vol 8 (4) ◽  
pp. 73
Author(s):  
Sindhu Preetham Burugupally
Keyword(s):  
Heat Input ◽  
High Speed ◽  
Performance Metrics ◽  
Large Displacement ◽  
Lumped Parameter Model ◽  
Thermal Actuator ◽  
Free Piston ◽  
Lumped Parameter ◽  
Peak Pressures ◽  
Actuator Design

A combustion-based mesoscale thermal actuator is proposed and its performance is studied in both open and closed cycle operations using a physics-based lumped-parameter model. The actuator design is unique as it implements a free-piston complaint architecture where the piston is free to move in a linear direction. Our objective is to study the actuator behavior in both the cycles to help identify the benefits and highlight the differences between the two cycles. The actuator is modeled as a spring-mass-damper system by taking an air standard cycle approach. Three observations are reported: (1) for nominal heat inputs (140 J/cycle), the actuator can produce large displacement strokes (16 cm) that is suitable for driving mesoscale robots; (2) the efficiency of the actuator depends on the heat input; and (3) for a specific heat input, both the open and closed cycles operate differently—with different stroke lengths, peak pressures, and thermal efficiencies. Our study reveals that the performance metrics of the actuator make it an ideal candidate for high speed, large force, and large displacement stroke related applications.

scholarly journals Analysis of Intrinsic Switching Losses in Superjunction MOSFETs Under Zero Voltage Switching

Energies ◽  
2020 ◽  
Vol 13 (5) ◽  
pp. 1124
Author(s):  
Maria Rogina ◽  
Alberto Rodriguez ◽  
Diego G. Lamar ◽  
Jaume Roig ◽  
German Gomez ◽  
...  
Keyword(s):  
Simulation Models ◽  
Soft Switching ◽  
Energy Losses ◽  
Switching Frequency ◽  
Zero Voltage Switching ◽  
Power Transistors ◽  
Switching Losses ◽  
Light Load ◽  
High Switching Frequency ◽  
Output Capacitance

Switching losses of power transistors usually are the most relevant energy losses in high-frequency power converters. Soft-switching techniques allow a reduction of these losses, but even under soft-switching conditions, these losses can be significant, especially at light load and very high switching frequency. In this paper, hysteresis and energy losses are shown during the charge and discharge of the output capacitance (COSS) of commercial high voltage Superjunction MOSFETs. Moreover, a simple methodology to include information about these two phenomena in datasheets using a commercial system is suggested to manufacturers. Simulation models including COSS hysteresis and a figure of merit considering these intrinsic energy losses are also proposed. Simulation and experimental measurements using an LLC resonant converter have been performed to validate the proposed mechanism and the usefulness of the proposed simulation models.

Transient Behavior of Seated Human Body During Input From Caudophalad Acceleration

2000 ◽  
Author(s):  
Paul C. Lam ◽  
P. Ruby Mawasha ◽  
Ted Conway
Keyword(s):  
Human Body ◽  
High Speed ◽  
Transient Behavior ◽  
Lumped Parameter Model ◽  
Load Factor ◽  
Time Duration ◽  
Bodily Injury ◽  
Lumped Parameter ◽  
Ejection Process ◽  
Short Time

Abstract The objective of this study, is to investigate the dynamic transient response of a four degree-of-freedom lumped parameter model of the seated human body subjected to caudocephalad loading (acceleration from tail to head). The caudocephalad loading used in the model simulated the ejection process of a seated pilot from a high-speed aircraft. During ejection, ejection velocities are high and are developed over short distances hence, the accelerations are also high (10–40 g’s). The model indicates that even though acceleration is applied over short time duration (typically less than 0.25 seconds), serious bodily injury can result due to high dynamic load factor for the frequency range of body resonances.

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