Gain Converter Research Articles

Determination of converter parameters for high-voltage electromechanical systems of stationary installations of industrial fans

Purpose. To study the electromagnetic processes in the circuit of the phase rotor of a high-voltage induction motor connected to the network through a step-up converter, to determine the parameters of the converter and their relationship with the voltage gain to ensure the optimal level of energy efficiency of the electromechanical system. Methodology. Methods of theoretical electrical engineering for the construction of a rotor circuit replacement scheme for an induction motor with a step-up converter, methods for solving a system of first-order differential equations, analytical methods. Findings. The expediency of using a converter that combines the rotor circuit of a high-voltage induction motor with the power supply network and provides regulation of the rotor EMF with the recovery of the slip energy of the induction motor rotor to the power supply network has been proved. This will ensure speed control of powerful high-voltage induction motors on the rotor side with an EMF of up to 600 V and significantly reduce the cost of a high-voltage electromechanical system. A methodology for determining the converter gain and the parameters of the rotor circuit of the electromechanical system is proposed, which allows determining the transformation ratio of the matching transformer at the optimal value of the voltage gain. The conditions of trouble-free operation of the inverter at the moment of start-up of the electromechanical system are determined. Achieving these conditions is ensured by determining the delay of the control signal to the power keys of the inverter of a step-up converter. The correlation between the voltage gain and the equivalent resistance of the rotor circuit of the electromechanical system is established. Originality. The ratio of the voltage gain to the equivalent resistance of the rotor circuit of the electromechanical system is established, which will ensure the matching of the rotor EMF with the voltage of the power supply network while maintaining a high level of energy efficiency. Practical value. A methodology for determining the gain and parameters of a step-up converter is proposed, which allows determining the transformation ratio of a matching transformer at the optimal value of the voltage gain. The proposed methodology can be applied to the modelling of complex powerful high-voltage electromechanical systems, especially for stationary installations of industrial fans.

Real-time monitoring and control of a PV-fed enhanced cubic voltage gain converter for DC microgrid

In this manuscript, a novel high-gain DC-DC converter with an ultra-step-up voltage gain value of 22.2 is introduced along with a custom-developed web application for remotely monitoring and controlling the power converter. The proposed converter is synthesized using two stages – stage 1 yields a cubic voltage gain and stage employs a diode-capacitor gain cell (DCGC) to reduce the voltage stress on the switch. The proposed gain extension hypothesis is experimentally validated through an 18 V to 400 V, 175 W prototype converter which delivers 175 W to the load at a 93.5% efficiency. The proposed converter exhibits excellent dynamic response when regulating the output voltage to 400 V over a wide range of input voltage and load current variations; the overshoots and undershoots are also negligible. Further, the maximum voltage stress on the switch is only 37.5% of the output voltage. For remotely controlling and monitoring the converter under real-time conditions with a high sampling rate, a web application is developed using React.js. The STM32 microcontroller is programmed to transmit data serially to the server, which then interacts with the web application using hypertext transfer protocol (HTTP) and WebSockets. The effectiveness of the developed interface is also practically verified by controlling the proposed converter in various modes viz., open-loop, soft-start, constant voltage, constant current, soft-stop, load regulation and overvoltage protection modes. Based on the comparison with several converters the proposed converter possesses unique advantages. Additionally, its web-based remote monitoring and control features are preferable for DC microgrid application.

Design of a high voltage gain converter using coupled inductor with reduced voltage stress for photovoltaic energy based systems

This paper presents the design and analysis of a high voltage gain converter utilizing a coupled inductor with reduced voltage stress, specifically for photovoltaic energy-based systems. The proposed converter employs a two-winding coupled inductor and voltage multiplier cells to achieve an increase in output voltage while mitigating voltage stress across semiconductor components. Additionally, the voltage multiplier cells function as voltage clamps for the power switch, further enhancing the converter's performance. The converter features a single switch design, which simplifies control, reduces cost, and improves reliability. Key advantages of the converter include a low component count, a common ground between input and output ports, and high efficiency. The converter's performance is thoroughly investigated through mode analysis and steady-state analysis. Comparative evaluations with similar converters are conducted to highlight the benefits and performance of the proposed design. To validate the theoretical analysis, a 125 W prototype with 26 V input and 200 V output voltages operating at a 50 kHz switching frequency is developed, and experimental results are presented, demonstrating the effectiveness and practicality of the proposed high voltage gain converter.

Extended high gain DC‐DC converter with switched‐inductors, switched‐capacitors and soft‐switching: Analysis and implementation

AbstractThis paper proposes an extended DC‐DC converter with high voltage conversion ratio and soft‐switching ability. The proposed converter has active switched‐inductors, switched‐capacitors included in the conventional high gain converter and operates in continuous conduction mode (CCM). Simple auxiliary resonant elements are added on the primary leg of the converter to provide design freedom for soft‐switching operation. The significant merits of the proposed converter are lesser voltage and current stresses, high voltage gain with reduced component count and better efficiency. Additional feature of this converter is soft‐switching operation under different load conditions and duty ratios without considerably increasing stresses. The zero voltage switching (ZVS) turn‐on operation is obtained for all switching devices. Therefore, switching power losses are minimized greatly. This paper presents the description, principles of operation and steady state analysis in comparison with the existing high gain converters. The theoretical analysis is verified with a 350 W prototype operated at input is 20 V and output is 220 V. The overall efficiency achieved is 96.7%. The obtained results confirm ZVZCS operation at full load.

Design and Implementation of an Interleaved High Efficiency and High Voltage Gain Converter With Minimum Switch Count for Renewable Energy Integration

Design and Implementation of an Interleaved High Efficiency and High Voltage Gain Converter With Minimum Switch Count for Renewable Energy Integration

Design and implementation of switched capacitor-based high gain converter

ABSTRACT This paper suggests a high gain Active Switched Capacitor, Switched Inductor, and Voltage Multiplier (ASC-SI-VM) based transformerless DC-DC boost converter to improve the static voltage gain, decrease the voltage stress and current stress of semiconductor devices and accomplish maximum efficiency. The switched inductor cell ensures a continuous source current, and the multiplier cell boosts the output voltage. The voltage conversion ratio analysis, stress expressions and power loss analysis of all the devices are derived. Comparisons are made between the proposed ASC-SI-VM converter topology and existing topologies in terms of static gain, voltage and current stress, and component count. The efficiency of 94.01% is attained for a 20 V/200 V voltage rating and a rated power of 100 W. The experimental topology of the proposed ASC-SI-VM converter is created to confirm the simulated and theoretical values.

A high step-up soft-single switched converter with three coupling inductors

ABSTRACT This paper presents a new high voltage gain converter, which bases on the incorporation of the voltage multiplier cell and the switched coupled inductor technique, having low voltage stress on the switch, which is far from the output voltage. The presented topology is well suited for high step-up applications. By integrating coupled inductors and voltage multiplier cell techniques, a high step-up voltage gain is achieved. All of the semiconductor devices are switched under soft switching conditions, which reduces the switching losses significantly. The switch turns on at ZCS and turns off at ZVS. All diodes have soft-switching features and their reverse recovery problem is obviated due to the leakage inductance. The operation principles and theoretical analysis of proposed converter are presented in details. At the end, the experimental results have been taken from a laboratory prototype rated at 100 W, input voltage of 24 V, output voltage of 300 V, and switching frequency of 100 kHz.

Unified control of high gain DC-DC converter for PV-battery hybrid system in a standalone and DC-microgrid applications

This paper presents power management and control of standalone PV and battery integrated hybrid system using high gain converter suitable for the DC Microgrid applications. The necessity of high gain DC-DC converter is raised due to generation of low output voltage of PV system. The attractive features of high gain converter are high voltage gain, continuous input current and suitability for integration of multiple input sources. The perturb and observe algorithm is used for tracing the maximum power point from solar and intermittency of solar is compensated by energy storage element battery. In the suggested hybrid system, the battery charging is carried out from DC bus voltage through buck converter and discharging to the load through high gain DC-DC converter. In the proposed work, Simulink model of proposed system rated for 1.2 kW PV module, 120 V, 42 Ah battery is developed using Simulink of MATLAB software and results are obtained under different operating conditions. Scaled experimental model of proposed hybrid system is implemented in laboratory environment using STM32F407VGT6 microcontroller and results are validated.

A Stacked Symmetrical Non-Isolated High Step-Up Voltage Gain Converter with High Efficiency and Low Voltage Stress on Components

This paper introduces a cascaded symmetrical non-isolated high step-up voltage gain converter with high efficiency and low voltage stress on components combining a non-isolated buck-boost converter and voltage doubler structure. In the proposed converter, the input source is connected in series to the output load; hence, a part of the source energy is directly delivered from source to load, not through the switching branch, improving efficiency. Furthermore, the appropriately stacked voltage doubler stage not only amplifies the high step-up voltage gain ratio but also considerably diminishes the voltage stress on all semiconductor devices and capacitors. As a result, the costless low internal resistance and low voltage components can be employed for higher efficiency, higher power density, and lower cost. To demonstrate the practicality of the proposed topology, the operating principle is outlined, and the steady-state characteristics are thoroughly analyzed. Furthermore, a 360 W prototype converter has been fabricated to confirm the efficiency of the proposed converter.

Design of fuzzy logic controlled zero voltage switching based interleaved high gain converter

The conversion of low level DC voltage to high level DC voltage at lower duty ratios with less ripple current at source side is a challenging task in the distributed generation systems. Active switched inductor (ASL) converter is a high gain converter and has a large amount of input ripple current due to the parallel charging of the inductors during on time of the switches and series discharge of the inductors during off time of the switches. This large input ripple current in the converter when used in distributed generation (DG) affects the life time of low voltage batteries and fuel cells, the efficiency of photovoltaic source, increases the size and losses in the filtering stages and decreases the power density of the converters. In this paper, soft switching of interleaved active switched inductor (IASL) through Zero Voltage Switching (ZVS) is designed to overcome the limitations of ASL. The performance is analyzed in terms of its gain, input current ripple, switching loss and efficiency. An M-type resonant switch is used to achieve soft switching through ZVS technique.A proper value of resonant elements (inductor and Capacitor) is designed to achieve ZVS to improve the efficiency. Regulated voltage of proposed converter is required in DG systems and is possible with closed loop control. Fuzzy Logic controller (FLC) is designed to regulate the voltage and its dynamic performance is analyzed for different load values and also for sudden changes in load. Hardware model of the proposed ZVS based IASL converter with FLC is implemented and the results are verified with simulation results obtained from MATLAB Simulink.

An inimitable Elman network based fire hawk controller and skill optimized power tracker with ultra gain converter for improving the performance of PV tied EV systems

The need for Electric Vehicles (EVs) has grown as a result of the issues brought on by fossil fuels. To keep up with the rising demand for electricity, the power source is equipped with additional renewable energy sources (RES). In order to meet the demand for energy, the solar photovoltaic (PV) system is deployed in this work. The novel contribution of this paper is the design and development of unique converter and regulating models to improve the overall power tracking performance, voltage gain, power quality, motor performance and efficiency of the PV-EV system. Here, a cutting-edge MPPT controlling model known as, Skill Optimized Power Tracker (SOPT) is developed in this work to maximize the quantity of electrical energy generated by solar panels in the context of changing temperature and irradiance. This work effectively increases PV output by adopting an innovative Ultra high gain converter, which increases voltage gain efficiency with less switching stress and power loss. In particular, this endeavor develops a unique Inimitable Elman Network based Fire Hawk Controller (IEFC) to improve the power quality and motor performance of EVs. Moreover, the simulation results of the proposed SOPT-IEFC controlling model and Ultra-high gain converter are validated through an array of performance measures including overall efficiency (99%), THD (1.05%), and motor speed (1200 rpm).

Design Recommendations Considering Charging Pads’ Self-Inductance Variation With LCC–S and LCC–LCC Compensation Based IPT Chargers in Low Clearance EVs

Inductive Power Transfer (IPT) based Electric Vehicle (EV) charging systems practically experience self-inductance variation in charging pads with air-gap, especially for low ground-clearances. Conventional design model ignores these variations, resulting in poor sizing and performance. This paper presents a comprehensive theoretical modelling and evaluation of system’s performance considering self-inductance variation for LCC-Series (LCC-S) and LCC-LCC type compensation. The work begins by examining various types of charging-pads with similar design-specifications, and finds circular-pad to exhibit least self-inductance variation. Subsequently, through extensive theoretical analysis, several contour-plots are derived, depicting variation of output voltage/current, output power, input Volt-Ampere (VA), input power-factor, and VA of compensation elements with various load and coupling-coefficient, for both the conventional and proposed models systematically. It is shown that proposed model provides accurate design recommendations over conventional model on various critical parameters, including optimal load, charging-time, dc-link voltage, maximum gain of secondary-side dc-dc converter, and VA ratings of the input and compensation elements. For example, proposed model predicts that a 7% increase in self-inductance with LCC-S type compensation (designed for 5kW) leads to 36.4% reduction in maximum output power, requiring compensatory increases in dc-bus voltage by 25.3% and input VA rating by 34.47%. The proposed model is validated experimentally.

Design and implementation of grid tied high step-up DC-DC converter with switched capacitor

In this paper, the design and implementation of a three-phase grid-connected inverter coupled with a high step-up DC-DC converter with a switched capacitor is demonstrated. In this converter two capacitors are utilized with a coupled inductor. The charging of capacitors takes place parallel and discharging in series during switch off and switch on time respectively. The energization of the coupled inductor provides the high voltage gain. The passive clamp circuit is used to recycle the leakage energy of the inductor circuit. Therefore, the switch stress is reduced. This high gain converter is given DC input of 40 V and a high voltage 538 V obtained is supplied to the grid connected inverter which uses sinusoidal pulse width modulation (SPWM), to obtain 3phase line-neutral voltage of 415 V from inverter for grid synchronization. A high voltage gain of 13 and efficiency of 96% is obtained for different load and voltage variation. The modeling and the simulation are done using physical security information management (PSIM) software and all the results are presented in this paper.

Analysis of single switch step up DC-DC converter with switched inductor-switched capacitor cells for PV system

The presented work exhibits high gain and increased efficiency for DC-DC converter. Additionally, this topology significantly improves the voltage conversion ratio when compared with other DC-DC converters reported recently. The non-existence of high frequency transformer ensures compactness and low cost and henceforth, it is apt for clean energy applications. The analysis of the high gain converter in steady state is carried out in continuous conduction mode (CCM). Initially, the proposed converter performance is analyzed using MATLAB/Simulink platform and prototype of the same with a power rating of 200 V, 100 W is built and tested. The reliability and robustness of the converter is perceived from the experimental results and peak efficiency achieved is around 93%.

High gain interleaved DC-DC converter with ripple-free input current and low device stress

ABSTRACT A non-isolated DC-DC converter which yields high voltage gain and suitable for photovoltaic (PV) applications is described in this research article. The high gain converter proposed in this paper is synthesised by combining several voltage gain extension techniques viz. coupled inductors, voltage-lift capacitor, and diode-capacitor multiplier (DCM) cells. Since the input stage is interleaved, and the switches are operated complimentarily, the source current ripple is nullified and switch current rating is minimised. Due to the hybrid voltage gain extension techniques adopted while synthesising the converter, the voltage stress on the switches is only 10.5% of the output voltage. To validate the proposed concept, experimental results are obtained from 18 V-380 V, 150W prototype converter which is operated at 50 kHz. The proposed converter yields a voltage gain of 21.11 at 92.83% efficiency under full-load condition. During closed-loop operation, the proposed converter quickly settles down to its nominal output voltage of 380 V when the input voltage and load current values are subjected to step variations. The superior features of the proposed converter are highlighted by comparing it with similar and recent state-of-the art high gain converters.

A Photovoltaic-based Novel Transformerless High Gain Converter for DC Microgrid Applications

Aim: A typical microgrid network sourced by renewable energy encounters a technical setback owing to the voltage imbalance across the source integration and load power dissemination. Transformers employed to stabilize the potential may deteriorate the network efficiency and increases the cost and size of the system as well. Introduction: Photovoltaic based transformerless high gain DC-DC converter (THG-DC) is proposed here to aid the microgrid infrastructure. Microgrid fuelled by renewable energy sources demands the high gain converter interface to boost low voltage generation. The proposed THG-DC is employed with four switched inductors and three active power switches (IGBT) which are brought together under dual leg configurations. Methods: The proposed topology offers dual-duty cycle modes of regulating the active switches to realize the desired output voltage. Moreover, it is reliable to drive the proposed THG-DC with lower values of duty cycles to achieve a higher gain. The voltage stress across the switches is minimized and the magnitude of inductor current ripples is quashed to an extent. The proposed THGDC is simple in architecture and easy to control in all three operating modes. Results: The operating characteristics and performance investigation of the novel converter during the continuous and discontinuous modes are elucidated briefly and the comparative analysis on switching stress, gain, and efficiency are executed to justify the standards of the proposed THGDC. Conclusions: Finally, the miniature prototype model is experimented with in the laboratory (0.3 kW) and the obtained results are in agreement with the theory. It is evident from the investigations that the proposed THG-DC shows its dominance over other converters on the voltage gain, switching stress, number of components, and overall efficiency.

Design and development of photovoltaic solar system based single phase seven level inverter

For solar photovoltaic (PV) systems, an upgraded triple gain seven-level inverter that works both independently and while connected to the grid is proposed. The two-stage configuration of the system is boost cascaded. The first stage has a one switch improved gain converter (OSIGC) to increase and normalize the input direct current (DC) voltage, and the second stage includes a unique seven level alternating current (AC) is produced via a multilevel inverter (MLI) design with triple voltage gain. The proposed OSIGC is appropriate for a broad range of conversions. The voltage gain in MLI was achieved using switched capacitor techniques. The DC-DC converter can achieve a maximum voltage gain of twelve and the MLI can achieve a maximum voltage gain of three, resulting in a DC-DC-AC voltage that can reach 36. Maximum power point tracking (MPPT) technique based on modified perturb and observe (PO) is used in OSIGC to maximise PV module power utilisation, and MLI control utilises sinusoidal pulse width modulation (SPWM) realistically. For the purpose of analysing the suggested system, a 200 Watt prototype statel is created. With a total harmonic distortion (THD) of 0.181%, up to 92.12% of the converter system’s overall efficiency is possible.

DC-DC high gain converter applied to renewable energy with new proposed to MPPT search

This paper presents the development of a high gain Boost converter applied to photovoltaic (PV) system. The converter was designed to be connected directly to the photovoltaic panel and perform the search for the maximum power point (MPPT). The new proposal seeks the MPPT is to connect each panel a converter for a high gain greater accuracy in finding the point of maximum power. The converter will work with input voltage of 17.7 Vdc, output voltage of 311 Vdc and power of 200 W.

Dual‐input single‐output high step‐up DC–DC converter for renewable energy applications

AbstractThis paper introduces a dual‐input single‐output (DISO) non‐isolated DC–DC converter with the capability to accommodate multiple input ports. It supports both bidirectional and unidirectional power flows. The proposed converter employs the switched‐capacitors (SC) technique, resulting in a high‐ voltage transfer gain. Although the use of the SC technique leads to discontinuous input current, this issue has been addressed by incorporating an inductor at the input side. The DISO high‐voltage gain converter offers flexible control options, reduces current and voltage stress on semiconductors, and imposes no duty cycle limitations due to the proposed switching methods. Furthermore, when Port 2 fails, the proposed converter can transfer energy to the load by sources in Port 1 without interruption. The steady‐state model and small‐signal analysis (SSA) of the proposed converter are examined at continuous conduction mode (CCM). To evaluate accurately, the proposed converter is compared with the recently presented converters based on important characteristics. Additionally, a comprehensive power loss analysis is performed. Following the design specifications, an evaluation and testing of a prototype are conducted to verify the feasibility and performance of the converter.

Power Quality Gain of Self-Lift Luo Converter used for Hybrid Renewable Power System with Battery Grid Integration

The renewable power sources such as wind as well as photovoltaic (PV) energy are fashionable for residential and commercial applications. For the reason, that eco friendlessness plus expenditure are effective. This paper intends a Self-Lift Luo converter integrated with solar photovoltaic system to the utility grid along with its Adaptive Neuro-Fuzzy Inference System (ANFIS) and Recurrent Neural Network (RNN) control strategies are proposed. By achieve an energy management for the proposed system using Bidirectional Battery converter along with battery system. Power supervision move towards is suggested to control the DC bus voltage by way of Self-Lift Luo converter. The wind power with Doubly Fed Induction Generator (DFIG) based grid integration with a PI controller. Under this work, DSTATCOM has been used to improve the quality of power under different load conditions. The obtained results designate that the proposed approach delivers recovered performance with enhanced efficiency and nominal harmonics. The intact system is validated through a MATLAB simulation.