CSF-PC based grid tied improved hybrid three quasi Z source converter

2020 ◽  
Vol 39 (4) ◽  
pp. 927-942
Author(s):  
Ramanjaneyulu Alla ◽  
Anandita Chowdhury
Keyword(s):  
Dynamic Response ◽  
Pi Controller ◽  
Duty Ratio ◽  
Switching Frequency ◽  
Control Voltage ◽  
Grid Integration ◽  
Voltage Gain ◽  
Content Type ◽  
Grid Current ◽  
Predictive Controller

Purpose A new control method is proposed for grid integration of improved hybrid three quasi z source converter (IHTQZSC). The proposed controller provides a constant switching frequency with an improved dynamic response with fewer computations. The proposed constant switching frequency predictive controller (CSF-PC) does not need weighting factors and reduces the complexity of the control circuit. Design/methodology/approach A single PI controller is intended to control voltage across dc-link by generating the necessary shoot-through duty ratio. The predictive controller produces the modulating signals required to inject the desired grid current. The performance of the proposed controller is validated with MATLAB/Simulink software. Findings The discrete-time instantaneous model on the grid side in the proposed controller influences the inductor current with minimum ripples. Dynamic response and computational complexity of the converter with the PI controller, finite set model predictive controller (FS-MPC) and the proposed controller are discussed. Practical implications The converter belongs to impedance source converters (ISC) family, delivers higher voltage gain in a single-stage power conversion process, extract the energy from the intermittent nature of renewable energy conversion systems. Implementing CSF-PC for ISC is simple, as it has a single PI controller. Originality/value Grid integration of high voltage gain IHTQZSC is accomplished with PI, FS-MPC and CSF-PC. Though the FS-MPC exhibits superior dynamic response under input voltage disturbance and grid current variation, total harmonic distortion (THD) in the grid current is high. CSF-PC provides better THD with a good dynamic response with reduced inductor current ripples.

A new technique for right half plane zero elimination from dynamics of a boost converter using magnetic coupling concept

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Alireza Goudarzian
Keyword(s):  
Dynamic Response ◽  
Half Plane ◽  
Phase Structure ◽  
Voltage Regulation ◽  
Boost Converter ◽  
Open Loop ◽  
Positive Zero ◽  
Voltage Gain ◽  
Minimum Phase ◽  
Content Type

Purpose Control-signal-to-output-voltage transfer function of the conventional boost converter has at least one right-half plane zero (RHPZ) in the continuous conduction mode which can restrict the open-loop bandwidth of the converter. This problem can complicate the control design for the load voltage regulation and conversely, impact on the stability of the closed-loop system. To remove this positive zero and improve the dynamic performance, this paper aims to suggest a novel boost topology with a step-up voltage gain by developing the circuit diagram of a conventional boost converter. Design/methodology/approach Using a transformer, two different pathways are provided for a classical boost circuit. Hence, the effect of the RHPZ can be easily canceled and the voltage gain can be enhanced which provides conditions for achieving a smaller working duty cycle and reducing the voltage stress of the power switch. Using this technique makes it possible to achieve a good dynamic response compared to the classical boost converter. Findings The observations show that the phase margin of the proposed boost converter can be adequately improved, its bandwidth is largely increased, due to its minimum-phase structure through RHPZ cancellation. It is suitable for fast dynamic response applications such as micro-inverters and fuel cells. Originality/value The introduced method is analytically studied via determining the state-space model and necessary criteria are obtained to achieve a minimum-phase structure. Practical observations of a constructed prototype for the voltage conversion from 24 V to 100 V and various load conditions are shown.

scholarly journals Simulation and Steady State Analysis of a Non-isolated Diode Rectifier-fed DC-DC Boost Converter with High Static Voltage Gain

2021 ◽  
Vol 7 (03) ◽  
pp. 20-25
Author(s):  
V. Girija and Dr. D. Mural
Keyword(s):  
Steady State ◽  
Output Voltage ◽  
Current Mode ◽  
Open Loop ◽  
Duty Ratio ◽  
Switching Frequency ◽  
Voltage Gain ◽  
Voltage Profile ◽  
Sinusoidal Input ◽  
Bridge Rectifier

This paper presents the simulation and analysis of a non-isolated step-up DC-DC converter operating in continuous inductor current mode with fixed switching frequency. The proposed converter proves better steady state performance in terms of improved voltage gain compared to the conventional boost configuration. The suggested two stage converter topology is fed by an uncontrolled diode bridge rectifier for which the sinusoidal input AC voltage is (50/ 2 ) V (rms). The design of the converter is such that the input AC voltage of (50/ 2 ) V (rms) is stepped up to around 256 V (DC) at the load end for the duty ratio value of 0.8. The performance of the proposed converter configuration is validated through simulation in Matlab/Simulink platform. The open-loop configuration provides higher constant output voltage profile compared to the conventional boost topology. The output voltage and current profiles show reduced settling time with almost no overshoot. The output voltage ripple is reduced to lower value. The suggested configuration ensures that the voltage-current stress across the switches is also reduced.

Performance Improvement of SVPWM-Based Three-Phase Grid-Connected Inverters

2013 ◽  
Vol 732-733 ◽  
pp. 1261-1264
Author(s):  
Zhi Lei Yao ◽  
Lan Xiao ◽  
Jing Xu
Keyword(s):  
Dynamic Response ◽  
Control Strategy ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Grid Current ◽  
Current Controller ◽  
Three Phase ◽  
Reference Grid ◽  
Grid Connected Inverter

An improved control strategy for three-phase grid-connected inverters with space vector pulse width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d-and q-axes grid currents is interacted in the traditional control method, and the waveform quality of the grid current is poor. As the reference output voltage cannot directly reflect the change of the reference grid current with the traditional control strategy, the dynamic response of the grid-connected inverter is slow. In order to solve the aforementioned problems, the d-and q-axes grid currents in the decoupled components of the grid current controller are substituted by the d-and q-axes reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results show that the grid-connected inverter with the improved control strategy has high waveform quality of the grid current and fast dynamic response.

A high-power PCCM LED driver based on GaN eHEMT with hybrid dimming modes

Circuit World ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xixian Lin ◽  
Yuming Zhang ◽  
Yimeng Zhang ◽  
Guangjian Rong
Keyword(s):  
Printed Circuit Board ◽  
Pulse Width Modulation ◽  
Circuit Board ◽  
Switching Frequency ◽  
Led Driver ◽  
Power Circuit ◽  
Content Type ◽  
Wide Range ◽  
Circuit Function ◽  
Pwm Dimming

Purpose The purpose of this study is to design a more flexible and larger range of the dimming circuit that achieves the independence of multiple LED strings drive and can time-multiplex the power circuit. Design/methodology/approach The state-space method is used to model the BUCK circuit working in Pseudo continuous conduction mode, analyze the frequency characteristics of the system transfer function and design the compensation network. Build a simulation platform on the Orcad PSPICE platform and verify the function of the designed circuit through the simulation results. Use Altium Designer 16 to draw the printed circuit board, complete the welding of various components and use the oscilloscope, direct current (DC) power supply and a signal generator to verify the circuit function. Findings A prototype of the proposed LED driver is fabricated and tested. The measurement results show that the switching frequency can be increased to 1 MHz, Power inductance is 2.2 µH, which is smaller than current research. The dimming ratio can be set from 10% to 100%. The proposed LED driver can output more than 48 W and achieve a peak conversion efficiency of 91%. Originality/value The proposed LED driver adopts pulse width modulation (PWM) dimming at a lower dimming ratio and adopts DC dimming at a larger dimming ratio to realize switching PWM dimming to analog dimming. The control strategy can be more precise and have a wide range of dimming.

Switching behaviour in activity-based working environments: an exploration of the reasons and influencing factors

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Eunji Häne ◽  
Lukas Windlinger
Keyword(s):  
Influencing Factors ◽  
Design Methodology ◽  
Online Survey ◽  
Facility Management ◽  
Switching Frequency ◽  
Push Factors ◽  
Content Type ◽  
Activity Settings ◽  
Working Environments ◽  
Switching Behaviour

Purpose A tendency that employees do not frequently switch between different activity settings was reported in previous studies, which are opposed to underlying assumptions of activity-based working (ABW) offices. Although ABW is increasingly becoming a standard office concept, employees’ switching behaviour has not been studied in depth. This study aims to understand employees’ switching behaviour by identifying reasons (not) to switch and various influencing factors of switching behaviour. Design/methodology/approach An online survey was conducted across Switzerland and Belgium, and 124 respondents participated in the questionnaire. The mismatch model was developed to examine whether the misfit between either activity or preference and work environment leads to switching to another place in the office. Findings Results show that most of the respondents switch multiple times a day, which runs counter to the previous studies. Furthermore, this study presented clear evidence that mandatory switching frequency is independent of various factors presented in the study, indicating that the distinction between mandatory and voluntary switching is valid. Besides, results identified privacy, acoustics, distraction, proximity to team/colleagues as reasons to switch and as reasons not to switch, place preference/attachment, proximity to the team were determined. Originality/value This study contributed to better understanding switching behaviour by defining, distinguishing switching behaviour, identifying reasons (not) to switch and influencing factors of switching frequency. In addition, this study compared the misfit between activity and environment and the misfit between preference and environment as push factors leading to switching behaviour. These findings can provide more knowledge of switching behaviour to workplace or facility management practitioners.

scholarly journals High Step-up Coupled Inductor Inverters Based on qSBIs

Energies ◽  
2019 ◽  
Vol 12 (15) ◽  
pp. 3032 ◽  
Author(s):  
Hongchen Liu ◽  
Xi Su ◽  
Junxiong Wang
Keyword(s):  
Steady State ◽  
High Voltage ◽  
Low Voltage ◽  
Duty Ratio ◽  
Voltage Gain ◽  
Passive Components ◽  
Steady State Analysis ◽  
High Voltage Gain ◽  
Voltage Stress ◽  
Working Principle

In this paper, two types of high step-up coupled inductor inverters based on qSBIs (quasi- switched boost inverters) are proposed. By applying the coupled inductor to the qSBIs, the voltage gain of the proposed inverter is regulated by turn ratio and duty ratio. Thus, a high voltage gain can be achieved without the circuits operating at the extreme duty cycle by choosing a suitable turn ratio of the coupled inductor. In addition, the proposed circuits have the characteristics of continuous input current and low voltage stress across the passive components. A boost unit can be added to the proposed inverters for further improvement of the voltage gain. In this paper, the working principle, steady state analysis, and the comparisons of the proposed inverter with other impedance-source inverters are described. A 200 W prototype was created and the experimental results confirm the correctness of the analysis in this paper.

Sensorless finite-state predictive torque control of induction motor fed by four-switch inverter using extended Kalman filter

2018 ◽  
Vol 37 (6) ◽  
pp. 2006-2024 ◽  
Author(s):  
Mohamed Chebaani ◽  
Amar Goléa ◽  
Med Toufik Benchouia ◽  
Noureddine Goléa
Keyword(s):  
Kalman Filter ◽  
Induction Motor ◽  
Extended Kalman Filter ◽  
Direct Torque Control ◽  
Operating Conditions ◽  
Torque Control ◽  
Switching Frequency ◽  
Content Type ◽  
Finite State ◽  
Torque Ripples

Purpose Direct Torque Control (DTC) of induction motor drives is a well-established technique owing to features such as fast dynamic and insensibility to motor parameters. However, conventional DTC scheme, based on comparators and the switching table, suffers from large torque and flux ripples. To improve DTC performance, this study aims to propose and implement a sensorless finite-state predictive torque control using extended Kalman Filter in dSPACE environment. Design/methodology/approach This paper deals with the design of an extended Kalman filter for estimating the state of an induction motor model and for sensorless control of systems using this type of motor as an actuator. A complex-valued model is adopted that simultaneously allows a simpler observability analysis of the system and a more effective state estimation. Findings Simulation and experimental results reveal that the drive system, associated with this technique, can effectively reduce flux and torque ripples with better dynamic and steady state performance. Further, the proposed approach maintains a constant switching frequency. Originality/value The proposed speed observer have been developed and implemented experimentally under different operating conditions such as parameter variation, no-load/load disturbances and speed variations in different speed operation regions.

scholarly journals Research on Energy Storage Interface Circuit and Its Control Principle Based on the L-LLC Resonant Bidirectional DC-DC Converter

2018 ◽  
Vol 36 (5) ◽  
pp. 926-932
Author(s):  
Ming Shen ◽  
Xiaobin Zhang
Keyword(s):  
Energy Storage ◽  
Dynamic Response ◽  
Optimal Trajectory ◽  
Hybrid Control ◽  
Power Grid ◽  
Operating Efficiency ◽  
Switching Frequency ◽  
Operation Performance ◽  
Interface Circuit ◽  
Zero Current Switching

Aiming at the low operating efficiency and poor dynamic response of energy storage interface circuit for flexible interface of connecting microgrid to power grid, the principle of PI or PID and optimal trajectory hybrid control based on the L-LLC resonant bidirectional DC-DC converter (L-LLC BDC) is proposed. It realize zero-voltage switching and zero-current switching for input switches and output rectifiers respectively, besides, it not only significantly reduce the computational complexity and further increase switching frequency, but also improve dynamic response of the converter remarkably. Using state-plane analysis, the operation status and characteristics of L-LLC-BDC are described in detail, based on that, the control system of the energy storage interface circuit is designed. In view of the principle of PI or PID and optimal trajectory hybrid control based on the L-LLC-BDC, the simulation shows that the correctness of theoretical analysis and the superiority of dynamic response and the operation performance of flexible interface of connecting microgrid to power grid is guaranteed.

scholarly journals Fractional Order PID Controlled Cascaded Re-boost Seven Level Inverter Fed Induction Motor System with Enhanced Response

2018 ◽  
Vol 9 (4) ◽  
pp. 1784
Author(s):  
P. Bhaskara Prasad ◽  
M. Padma Lalitha ◽  
B. Sarvesh
Keyword(s):  
Dynamic Response ◽  
Induction Motor ◽  
Motor System ◽  
Single Phase ◽  
Closed Loop ◽  
Photovoltaic System ◽  
Voltage Response ◽  
Voltage Gain ◽  
Boost Regulator ◽  
Fractional Order Pid

<span lang="EN-US">Recently, Re-boost seven-level inverter has been developed as an alternative between Photovoltaic system and single-phase load. DC level is increased using a re-boost regulator and its output is rehabilitated into single-phase AC utilizing a seven-level inverter. The re-boost converter is utilized to escalate the voltage gain. The objective of the suggested closed loop Re-boost Seven Level Inverter fed Induction Motor (RBSLIIM) system is to enhance the dynamic response of RBSLIIM using FO-P-I-D controller. Simulink models are developed for P-I and FO-P-I-D controlled RBSLIIM systems. The results of P-I and FO-P-I-D based RBSLIIM systems indicate that the voltage response with FO-P-I-D is superior to P-I controlled RBSLIIM system.</span>

scholarly journals PI- Controlled PV Fed Fly Back Converter with Enhanced Dynamic Response

2019 ◽  
Vol 8 (2S11) ◽  
pp. 4031-4034
Keyword(s):  
Steady State ◽  
Dynamic Response ◽  
Rise Time ◽  
Closed Loop ◽  
Input Voltage ◽  
Pi Controller ◽  
Open Loop ◽  
Load Variations ◽  
Simulink Model ◽  
Step Down

Fly back converter is the most popular converter because of its simplicity, low part counts and isolation. It occupies less volume and it saves cost. Fly back converter steps up and step down the voltage with the same polarity. Open loop operation remains insensitive to the input voltage and load variations. Matlab Simulink model for Fly back converter is established using PI controller. Open loop Fly back converter system and closed loop fly back converter systems are simulated and their outcomes are compared. Comparison is done in terms of Rise time ,Settling time and steady state error

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