DC Input Research Articles

A New Single-Phase Flying Inductor-Based Common Grounded Converter for Dual-Purpose Application

This paper presents a new common grounded flying inductor-based converter as power electronics interface suitable for application in both dc or single-phase ac grids using the same terminals. This topology enables direct connection of the negative terminal of the input dc power supply to the negative polarity of the converter output. Therefore, the leakage current is eliminated completely. The voltage boosting feature in single-stage and operation in a wide range of input dc power supply is the other benefit of the proposed solution. Since electrolytic capacitors are not used in the structure, the life of the converter is increased. The operation modes of the converter are explained in detail. Also, the design considerations for passive elements are discussed. To verify the accuracy of the performance of the proposed topology, a laboratory prototype (3.6 kW/6 kW) was built. Related experimental results are presented.

Voltage Regulating Strategy of a New LCC/S+L Inductive Power Transfer System

In the voltage control of the inductive power transfer (IPT) system, a cascaded DC-DC converter is normally adopted which reduces the power density. However, the wireless communication between the transmitter and the receiver may lead to a delay of control as well as communication instability. This paper proposes a new LCC/S+L resonance topology for the IPT system, which can realize single-stage voltage regulation on the receiving side with both buck and boost capability. Based on the fundamental wave analysis method, this paper analyzes the working principle of LCC/S+L resonant topology. Then the control strategy of the phase shift angle between bridges and within bridges is obtained by the voltage of both ends of the series inductor and the load voltage vector. It is verified by simulation that the proposed new resonance topology and control strategy can achieve output voltage regulation of 300-500 V with a constant 375 V input DC voltage.

Real-time implementation of sliding mode controller for standalone microgrid systems for voltage and frequency stabilization

This paper presents for stabilizing the output voltage and frequency of the hybrid source microgrid system (HSMG) and standalone solar photovoltaic microgrid system (SAPV), under varying source and loading conditions. An HSMG system consists of a solar, wind and battery system incorporated with a solar boost converter, wind rectifier/boost converter and bidirectional converter, respectively. These different dc level outputs are applied to the multiple input dc–dc converter for obtaining the constant dc level and then converted into three-phase power with suitable inverters. The source-side converters are designed to obtain the maximum output irrespective of the input conditions with PI controllers. The multiple input dc–dc converter controls the dc link voltage with the well-designed proportional, proportional integral, proportional integral derivative controller. The three-phase inverter is premeditated to obtain the constant voltage and frequency even under varying load patterns. The tuning of the PID controller is incorporated with Ziegler Nichols’s technique to reduce the frequency deviation and steady-state error. A SAPV microgrid system is developed with a high-capacity solar system incorporated with two-stage power conversion. Stage 1 and 2 are constant dc/constant ac obtained using suitable converters incorporated with an adaptive controller. The sliding mode controller (SMC) is an adaptive controller that performs better in dynamic operations. In this work, SMC maximizes the solar output and stabilizes the DC voltage using an appropriate PWM pulse to the boost converters. Also, the output voltage and frequency are maintained constant during the different operating situations. All simulations are carried out in MATLAB. PID and SMC controllers are implemented to the HSMG and SAPV microgrid systems in the OPAL-RT environment to validate the results in real-time applications respectively. The different operating conditions are tested for both the systems and the results prove that the chosen controllers are more suitable for these applications.

Design of Hybrid multi-level inverter for photovoltaic(PV) application

Nowadays the demand and consumption of energy increase in the word. Due to high cost of fossil fuel it’s not able to meet the required power generation demand. But the developed and developing countries encourage to generate power from renewable energy sources. The developed countries manage their resources in such a manner that they will fulfill their needs today and in the future as well. Nevertheless, the developing countries have limited sources of fossil fuels, which may decrease day by day. For this problem, the alternate solution is required, which is renewable energy. The output of renewable i.e. photovoltaic (PV) is DC. Now this is a challenging task for the researcher to integrate the renewable energy into the ac grid. For the reliable future of the power system, it is imperative for the modern era to integrate non-conventional sources into the AC power grid.The use of photovoltaic cells is increasing dramatically in all areas of life because of their small environmental impact, pollution-free, minimal maintenance, and zero noise. The real work focuses on the integration of PV systems with the proposed new topology called Multi-level inverters based on switch dc sources for low, medium and high power applications. An inverter is a power electronics device that converts DC input to AC output voltage. Input DC voltage is obtains from PV cell array, fuel cell or any other source.The output of PV panels is use as DC input voltage source for the proposed inverter. Single-phase multi level inverter is use to convert dc power receiving form PV array to AC power. First single phase two level inverter introduce which have many problems like those that high value capacitor required at output and high total harmonics distortion’s (THD). Nevertheless, as the number of level increased in inverter output the number of electronic switches also increased which may increase the losses.Multi-level inverters are gave more attention for high power applications. In recent years, lower order harmonic components has been developed to operate at higher switching frequencies.On the other side as the number of level increased the output waveform approach to sinusoidal waveform and the harmonics decreased. Output voltage and current waveforms are obtains and THDs are analyze. The multi-level inverter used in un-interrupted power supply (UPS), variable frequency drives (VFD), pumps etc. The performance of single-phase multi-level inverter will be analyzed in MATLAB / Simulink software.

3D backside integration of FinFETs: Is there an impact on LF noise?

This paper compares the low-frequency noise performance of backside integrated pFinFETs versus their regular frontside-only processed counterparts. We report that no degradation of the dominant flicker noise is observed, comparing front- versus backside processed transistors. At the same time, application of a post backside processing annealing step(s) is shown to enable an improvement of the DC input characteristics and the low-frequency noise power spectral density of the devices.

Leg Conversion Method for the Continuous Control of a Railway Vehicle Propulsion Inverter

In this study, we propose a whole-leg scheme for the continuous control of a railway vehicle propulsion inverter. The three-leg method is commonly used to obtain the output AC power from the input DC voltage in a railway vehicle propulsion inverter. When the power semiconductor of an inverter operating in a three-leg manner fails, a problem occurs in the power supply. Therefore, this study proposes a method that automatically converts into the two-leg method without replacing the power semiconductor when it fails while the inverter is driven with the three-leg method. This leg conversion method can prevent problems in supplying power by converting the power that can be obtained from an inverter operating with the three-leg method into that obtained from an inverter operating with the two-leg method. In addition, to verify the effectiveness of the leg conversion method, a demonstrative experiment was conducted after a simulation, and an actual inverter was fabricated. Consequently, the experimental results confirmed that in an inverter operating with the three-leg method, even if the power semiconductor failed, it could be converted for operation with the two-leg method to supply power normally.

Efficiency and dynamic characteristics of improved dual‐stage power converter setup with advanced model predictive controller for electric vehicle battery charging

SummaryThis paper proposes an advanced power converter setup to charge an electric vehicle battery from a renewable energy source, such as solar photovoltaic. An improved Z‐source DC–DC boost converter (IZSBC) is utilized in the first stage. A synchronous rectifier (SR) of a phase‐shifted full‐bridge converter (PSFBC) with continuous conduction mode (CCM) is employed in the second stage using the zero voltage switching (ZVS) technique to provide isolation between the source and the load. To address the disadvantage of undesirable dynamic characteristics of the PSFBC‐SR, an advanced voltage control using the advanced model predictive controller (AMPC) is suggested to improve the dynamic characteristic of the PSFBC‐SR converter and prevent output voltage overshoot. An AMPC‐based new control method is preferred to eliminate body‐diode conduction for improved efficiency at any load conditions. Simulation and experimental designs of 0.5 kW with a 25 V DC input from the SPV, a boosted output of 100 V for a 60 V, 16 Ah battery bank and switching frequencies of 100 and 250 kHz for IZSBC and PSFBC‐SR, respectively, are produced and evaluated. Results show an efficiency of 93.7% with 31.44 W loss in simulations and 93.94% with 30.25 W loss in hardware tests. The preferred system has fast dynamics and is robust to sudden load impedance changes, thereby improving current tracking and reducing converter losses. The AMPC strategy proposed in this paper can increase conversion efficiency and control the output voltage without additional gain tuning.

Mathematical Modeling and Analysis of Capacitor Voltage Balancing for Power Converters with Fewer Switches

The multilevel inverter (MLI) has been developed as a powerful power conversion scheme for several processes, including renewable energy, transmission systems, and electric drives. It has become popular across medium- to high-power operations due to its many advantages, including minimum harmonic content, low switching losses, and reduced electromagnetic interference (EMI). In this paper, the capacitor voltage balancing technique-based pulse width modulation (PWM) has been proposed. The proposed PWM strategy offers several advantages, such as high-quality output waveforms with reduced harmonic distortion, improved efficiency, and better control over the output voltage. The Xilinx ISE 10.1 software was used for synthesizing, and the VHDL code was written for the proposed method. MATLAB software was used to simulate and hardware was used to verify the proposed system. The SPARTAN 3E FPGA was used for the generation of the PWM. This paper developed a 2 kW single-phase 15-level inverter that created an AC wave from the DC input voltage, with a total harmonic distortion (THD) of 8.02%, which was less than the THD achieved from other conventional MLI. The results indicate that MLI topologies with low total harmonic currents, fewer switches, and higher output voltage levels are better stabilized during load disturbance circumstances.

Modeling and Operation of Series-Parallel Resonant Load in Industrial RF Dielectric Heating Application

Radio Frequency (RF) based heating application is used in multiple industries like drying cross-laminated woods, food and packaging, melting silicon etc. These industrial RF heating plants operate at frequencies of 6.78 MHz, 13.56 MHz, or 27.12 MHz (ISM band). Historically, the high frequency requirement has forced the industry to rely on vacuum tube based RF generator, which are only 60% efficient. Modern semiconductors like wide bandgap (WBG) devices have achieved the high frequency operation that is required to replace the inefficient vacuum tubes. However, a comprehensive study of load network for an industrial RF heating plant has not been undertaken such that an existing plant can be retrofitted with semiconductor based turn-key solution. In this paper the authors present design equations for an industrial RF dielectric heating load structure and suggest necessary modifications required to replace vacuum tube RF generator with voltage source converter (VSC). A new figure of merit (FOM) is defined that impacts the load structure efficiency. Finally, a small-scale prototype load is manufactured as a case study. The prototype demonstrated an output power of 750 W at 6.76 MHz with an overall efficiency of 90% from DC input to RF load which can not be achieved with a vacuum tube technology.

Asymmetrical Fault Ride-Through and Power Oscillation Characterization for Grid-Tied Voltage Source Converters

As the number of converter-interfaced distributed energy resources connected to the power system continues to increase rapidly, recent grid codes require these grid-tied converters to maintain grid connection during fault to ensure power supply security and reliability. In this work, we analyze the oscillation in the injected real and reactive power that a grid-tied voltage source converter (VSC) introduces as it attempts to contribute to the power quality and improve the voltage at the point of common coupling (PCC) during an asymmetrical fault. We propose a new double sequence current reference generation method that can be utilized to derive a closed-form quantification of the peak value of both the real and reactive power oscillation during asymmetrical fault ride-through (AFRT) analytically. Effect of the resulting bus voltage oscillation and ripple current requirement at twice the grid frequency, corresponding to the real power oscillation, on the input DC bus capacitor and upstream converter is analyzed for facilitating system component sizing. Furthermore, the proposed current reference generation formulation helps control the negative-sequence current injection during fault to assist with fault identification. The theoretical analysis is validated through simulation in <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">PLECS</i> for both asymmetrical and symmetrical fault scenarios. Experimental results for a three-phase, grid-tied VSC operating under both asymmetrical and symmetrical faults are provided to evaluate the performance of the proposed current reference generation method and validate the analysis presented.

Development and Application of an Energy Management System for Electric Vehicles Integrated with Multi-input DC-DC Bidirectional Buck-Boost Converter

The rise in environmental pollution, demand for fossil fuels, and higher fuel economy vehicles has raised concerns about the creation of new and efficient transportation vehicles in recent days. These days, most developments in electric vehicles concentrate on making the vehicles more pleasant to ride in. Nonetheless, the emphasis now should be on energy and its most efficient use. To do this, you must give your attention to the origin of the automobile. The answer to this problem may be found in hybrid energy storage systems (HESS). This work is concerned with the design and implementation of an effective energy management system in electric vehicles (EVs) equipped with an active HESS consisting of a battery and a super capacitor via the incorporation of load sharing into this hybridization under a variety of load demand scenarios. To address the demands of high fuel efficiency vehicles, automotive firms are focusing on the development of diesel-engine operated vehicles, electric vehicles, fuel-cell vehicles, plug-in electric vehicles, and hybrid electric vehicles. A Multi-input Bidirectional Buck-Boost (MIB3) DC-DC converter is proposed in this dissertation to provide a greater conversion ratio to the input DC voltage. The multi-input converter recommended has fewer components and a simpler control method, making it more trustworthy and cost-effective. This converter also has bidirectional power flow functionality, making it suitable for charging the battery during regenerative braking in an electric or hybrid vehicle. Three different energy sources are used in the suggested topology: a photovoltaic (PV) panel, a battery, and an ultra-capacitor

Design and Testing of Electrosurgery Unit

Bleeding during surgery is common in major surgical operations. So, it is not recommended to make an incision using a conventional scalpel. As an alternative to replacing a conventional scalpel, an electric scalpel or know as electrosurgery unit (ESU) is made by utilizing a high frequency whose duty cycle can be adjusted and then being focused on one point is a solution to prevent bleeding. This research will design a bipolar electric scalpel or bipolar electrosurgical unit with a frequency of 210-250 KHz and an input voltage of 50-90 VDC to perform pure cuts on chicken meat samples. The box pulse frequency will be generated from IC 4069. The output of the oscillator generator will read the high and low voltage on the Arduino Nano digital pin. The current will be amplified at the oscillator output and then processed in the inverter driver circuit. The selection of the DC input voltage will use a voltage driver circuit. The inverter driver output and voltage driver will be step-up to get a maximum power of 10.4W with a resistance of 100Ω at a frequency setting of 210 KHz and an input voltage of 90 VDC and a minimum power of 1.4W with a resistance of 100Ω at a frequency setting of 250 KHz and input voltage 50 VDC.

Predicting the stability of smart grid for improving the sustainability using distributed generation technology

Distributed Generation balances the supply in the grid effectively. Numerous distributed power generation technologies need more efficiency, cost, and power output to meet the energy requirements. Hence, this paper has aimed to provide an efficient DG system by integrating a PV module with a smart grid through a 3-phase AC-DC converter. Numerous PV modules are combined through DC linking, and different inverter control strategies are used to control the network. The ANN algorithm is used to optimize the demand and supply in the network. PV modules are included in the network to boost up the renewable energy source for the network. The power generated from the PV module is converted to DC through 3 phase AC-DC converter. A DC-link modeling is carried out between various converters and PV modules. It helps balance the variation in the DC input from the PV modules converted by AC-DC converters. The input current is again sent into a closed-loop inverter system to control the input current appropriately based on the demand. The problems between demand and supply are sorted through an ANN algorithm that optimizes the whole model based on supply and demand. The whole is simulated, and the results obtained are discussed in detail. The results are compared with similar Distributed power generation technologies to compare their efficiency. The comparison clearly shows that the proposed model provides better environmental sustainability and expandability to the system.

Design of Cascaded Multilevel Inverter and Enhanced MPPT Method for Large-Scale Photovoltaic System Integration

The key goal of this effort is to develop an efficient control system for a three-phase cascaded H-bridge multilevel inverter powered by the photovoltaic (PV) system. The power for the system is generated through the use of PV modules, which serve as DC inputs for the cascaded H-bridge multilevel inverter. The authors aim to achieve a nearly sinusoidal signal at the voltage level and are specifically focused on minimizing the total harmonic distortion (THD) to the smallest possible value. Hence, an advanced N-level space vector modulation (SVM) is developed to ensure an appropriate control for the cascaded inverter. The aim is to design an effective control strategy to increase inverter efficacy and, thus, supply the best output quality. In addition, a robust approach to the maximum power point (MPP) tracking (MPPT) technique is developed based on an adaptive perturb and observe (P&amp;O) algorithm to ensure superior tracking of the MPP. The developed algorithm eliminates 90% of the power curve area in the search space process and only maintains 10% of the area that includes the MPP. Each PV system employs its own improved MPPT control. The numerical results confirm that the enhanced P&amp;O algorithm attains a precise response with superior efficiency and a fast response under the fast alteration of environmental conditions. Hence, the energy loss is reduced. The simulation results validate the effectiveness of this study, highlighting the high efficiency of the control strategy and the enhanced performance of the proposed scheme with lesser THD values.

Transients in Input and Output Signals in DC–DC Converters Working in Maximum Power Point Tracking Systems

Designing a maximum power point tracking system (MPPT) can raise many questions when it comes to choosing the best converter and algorithm for the job. The number of possible solutions can be overwhelming, especially when it comes to MPPT algorithms. New algorithms are often tested in simulation environments only, where the accuracy and speed of a single measurement (i.e., in a single step) are usually assumed and sometimes unintentionally exaggerated. In practice, even if the algorithm is fast, its speed is limited by other factors. This article emphasizes the time limitations that are related to converter parameters and that naturally exist in all maximum power point tracking systems. Additionally, the article proposes a measurement method that enables voltage and current measurements with good accuracy for different transients that exist at the input and output of DC–DC converters.

MHz‐driven snubberless zero‐current soft‐switching high step‐up DC‐DC converter with a multi‐resonant tank

AbstractA novel high step‐up DC‐DC converter suitable for the power interface of fuel cells (FC) is presented in this paper. The proposed converter features a multi‐resonant tank for achieving high‐step up ratio under zero current soft switching (ZCS) without any snubber circuits. The simple and minimized‐component topology is beneficial for megahertz driving of gallium nitride (GaN) power transistors with effective reductions of switching loss, electromagnetic emission interference (EMI) noise, and ripple‐free DC input current. Mode‐transitional power stages are described in detail, following that the high step‐up principle is revealed by means of frequency‐domain analysis. The essential performances of the proposed circuit topology are demonstrated by simulation and experiment of 1.8 MHz‐120W prototype whereby effectiveness of the snubberless and multi‐resonant topology are verified from the practical point of view.

All‐SiC 99.4%‐efficient three‐phase T‐type inverter with DC‐side common‐mode filter

AbstractThis letter presents a hardware demonstrator of an all‐SiC three‐level T‐type (3LTT) inverter with the common‐mode (CM) EMI filter stages placed on the DC input instead of the AC output side, targeting, for example, high‐efficiency PV applications. The extensive experimental characterization shows that state‐of‐the‐art SiC transistors and a DC‐side CM filter enable an unprecedented peak/full‐load efficiency of 99.4% (calorimetric measurement) at 12.5 kW and a power density of 2.4 kW/dm3(39 W/in3). The demonstrator fulfills CISPR 11 Class A EMI regulations as well as upcoming EMI standards for the frequency range of 9–150 kHz. Compared to other high‐efficiency converters, which often employ bridge legs with more output voltage levels, the described 3LTT concept thus offers a very favorable trade‐off between complexity and performance.

Impedance-Edited Multiple Low-Frequency Harmonic Current Adaptive Suppression

In the two-stage inverter, a large amount of low-frequency harmonic current will emerge in the front-end dc-dc converter and input dc voltage source. The low-frequency harmonic current will reduce the service life of the dc source and decrease the efficiency of the system. Additionally, the main components of low-frequency harmonic current fluctuate with uncertainty. To address those issues, an adaptive current suppression method based on impedance editing of the source-stage dc-dc converter is proposed in this paper. Compared with the traditional active power filter (APF), the proposed adaptive low-frequency harmonic current suppression method does not require additional circuits, which will never decrease the system efficiency but reduce the cost. More importantly, when the amplitude of the main components of harmonic current fluctuates, adaptive multiple bandpass filters are proposed to adaptively suppress the main harmonic current, which never influences the dynamic performance. In addition, the virtual impedance is connected in parallel with the bus capacitor to reduce the bus-voltage overshoot. The key parameters design of the proposed control strategy is given and the dynamic response of the proposed control strategy is also discussed. Finally, a prototype of 900W was fabricated and tested.

Build a DC to AC Inverter Circuit with IOT Based Load Monitoring

Abstract: The boost inverter or boost DC-AC converter is a new voltage source inverter (VSI) that is suggested in this research. The novel inverter topology's key feature is that, depending on the instantaneous duty cycle, it produces an AC output voltage that is greater than the DC input voltage. This characteristic is not present in the conventional VSI, which consistently generates an AC output instantaneous voltage lower than the DC input voltage. A sliding mode controller is suggested to optimize the boost inverter dynamics while guaranteeing proper functioning under any working circumstance. The primary benefit of sliding mode control over traditional control strategies is its resistance to changes in plant parameters, which results in invariant dynamics and steady-state response in in the best scenario. This study covers operation, analysis, control technique, and experimental outcomes. When an AC voltage greater than the DC link voltage is required, the new inverter is designed to be employed in UPS and AC driver systems without the requirement for a second power conversion stage

Thirteen-Level Switching Capacitor Inverter with Six Times Boost and Self-Balancing Capability

A thirteen-level inverter based on switching capacitor is proposed in order to improve the boost capacity and output power quality of inverter in renewable energy power generation system. The proposed topology is composed of one DC input power supply, three capacitors and 14 switching devices, and achieves thirteen-level output with six times voltage boost. It has smaller volume, lower cost and output harmonic content. Moreover, it can realize inverter without H bridge and reduce the voltage stress of switching tube. In addition, the proposed inverter can achieve self-balancing capacitor voltage without any auxiliary method, simplifying the complexity of control. The superiority of the proposed topology is verified by comparing with other traditional multilevel inverters. The simulation and experimental verification on the simulation and prototype platform show that the inverter has good performance in both steady and dynamic conditions.