Input DC Voltage Research Articles

Design and Implementation of Solar OLED Lighting Driver Circuit with Frequency Modulation Control

This paper proposes a single-stage single-ended primary inductor converter (SEPIC) converter circuit, which is applied to the organic light-emitting diodes (OLED) driver circuit. The circuit proposed in this paper replaces the output Schottky diode from the original SEPIC with a power switch. Deadtime is added to prevent the on-state overlapping of two switches with zero voltage switching (ZVS), and the circuit operates in triangular current mode. The digital control methods are maximum power point tracking and frequency modulation using a battery to supply the converter and illuminate the OLED at night. Finally, a prototype is implemented to show the feasibility under the DC input voltage range of 10–40 V. The DC output is 12 V/1 A/12 W, and the conversion efficiency is up to 96.3%.

Fuzzy Logic Control Design On Buck Converter For Thermo Electric Air Cooler Power Supply

The air conditioning system that is commonly used today is an Air Conditioner (AC). Unfortunately, this system is a big contributor to global warming. Often times, we find that air conditioners are only used to cool only a small part of a room for individual comfort. Therefore, a new breakthrough is needed from a cooling system that does not use chemicals so that it is environmentally friendly, namely using the Thermo Electric Cooler (TEC) cooling module which utilizes the cold side of the Thermo Electric Cooler (TEC). The size of the DC input voltage on the Thermo Electric Cooler (TEC) is adjusted using a buck converter with fuzzy control. When the buck converter closed loop condition with fuzzy control has a rise time value, the settling time and error percentage have a relatively better value than the open loop condition. When the buck converter set point 40V, the minimum water temperature in the air cooler can be reached 220C, when the buck converter set point is 48V the minimum water temperature in the water cooler can be reached 190C, and when the buck converter set point is 56V the minimum water temperature in the air cooler can be reached 180C. When the water cooler uses air cooler by Peltier, the input air temperature and output air temperature decrease in temperature around 10C. this is caused by the evaporative effect caused by water cooled by the peltier.

Isolated single-phase single-stage DC-AC cascaded transformer-based multilevel inverter for stand-alone and grid-tied applications

This paper proposes a new single-phase DC-AC Cascaded Transformer-based Modular Multilevel Inverter (CTMLI) with its PWM switching technique considering minimum components count per output voltage level. The proposed CTMLI converts the constant input DC voltage to 19-level AC voltage at its output terminals in a single-stage using only three full-bridge (FB) circuits in addition to three single-phase cascaded transformers. The three FB circuits are connected in parallel to the same DC supply, whereas the output terminals of the cascaded transformers are connected in series. In order to realize the 19-level output voltage, each FB circuit is controlled by different switching frequency and each single-phase transformer has different turn’s ratio. Detailed mathematical model of the proposed CTMLI is presented considering the optimal transformer turn’s ratio in addition to the power distribution among them. Also, cost estimation model for the MLI is presented in details in order to investigate the cost reduction in the proposed CTMLI. In addition, a detailed comparison with the recently published MLI is presented to confirm the merits of the proposed inverter. The validity of the proposed CTMLI has been investigated experimentally using laboratory prototype (220 V, 1.2 kW) controlled with dspace DS-1103 digital controller in stand-alone applications considering closed-loop voltage control and in grid-tied applications considering closed-loop current control.

Design and Simulation Converter with Buck-boost Converter as The Voltage Stabilizer

Buck-boost Converter is the device with the function to convert DC Voltage input to the setpoint DC Voltage output. Buck-boost converter can be used for regulating unstable voltage became a stable voltage by the user’s needs. Using a Buck-boost Converter in the research is about how to apply a Buck-boost Converter of the AC to AC Converter device, AC to AC Converter is the device to convert AC voltage to AC Voltage where the voltage can be modified. In the research, the input Voltage of AC to AC Converter is unstable, so that the output Voltage is unstable too in the range of 190 V to 250 V. To solve this problem, that the Buck-boost can be installed to AC to AC Converter, it is useful to keep output Voltage stable even though the input Voltage is unstable. The AC to AC Converter device in this research consist of Rectifier, Buck-boost Converter, and Inverter. The experiment result of this research show that unstable AC input Voltage, 190 V to 250 V from the source after passing a Rectifier, became an unstable DC input Voltage, then be regulated by Buck-boost Converter became a stable DC Voltage, and then after passing the Inverter, a stable DC Voltage is converted became a stable AC Voltage, corresponding with the set point. For further development, AC to AC Converter combined with Buck-boost Converter can be applied to maintain a standard of Voltage 220 V AC from the sources to keep it stable.

Control of a Single Stage Boost Inverter Based on Dynamic Sliding Mode Control with Power Decoupling

In this paper, the problem of control a single-stage boost inverter is studied. The goal is to achieve a system with robustness against variations in parameters, fast response, high-quality AC voltage, and smooth DC current. To this end, a new type of dynamic sliding mode control is proposed to apply to various scenarios such as parameter uncertainties and DC input voltages. In comparison with the conventional double-loop controllers, the proposed sliding mode controller utilizes only a single loop in its design, while having attractive features such as robustness against parametric uncertainties. In addition, a methodology is proposed for the decoupling of double-frequency power ripples based on proportional-resonant (PR) control to remove the low-frequency current ripples without using additional power components. Compared to conventional controllers, the proposed controller provides several features such as fast and chattering-free response, robustness against uncertainty in the parameters, smooth control, proper steady-state error, decoupled power and good total harmonic distortion (THD) over the output voltage and input currents, and simple implementation. In a fair comparison with classical sliding mode control, simulation results demonstrate more satisfactory performance and effectiveness of the proposed control method.

An S-CLC Compensated Load-Independent Inductive Power Relay System With Constant Voltage Outputs

This article proposes an S-CLC compensation network to achieve a relay system to power multiple gate drivers of series modules. There are three major contributions. First, it achieves the constant voltage (CV) and load-independent property, meaning the induced voltage on each receiver is immune to load variations. Second, the S-CLC circuit topology is compact to be constructed, and an integrated coil structure is proposed to limit the system size. Third, the efficiency of the power relay system is analyzed, including parasitic resistances of resonant components and coils, which reveal the load regulation phenomenon in practical applications. In order to validate the proposed topology, the parameter design methodology to achieve the highest efficiency is proposed, and a single-input-four-output prototype is implemented. The coil size is 180 mm × 175 mm, the transfer distance between receivers is 50 mm, and the switching frequency is 200 kHz. When the input dc voltage is 18 V, the induced voltage of each receiver is around 15 V, and the voltage difference between receivers is within 2 V. When the load resistances vary in a wide range from 15 to 100 Ω, the output voltage regulation rate is within 17.01%. The maximum power of the receiver can reach 13.53 W, and the maximum efficiency can reach 89.79%, showing that the proposed system can be used in practical applications. Besides, the prototype is exploited to power gate drivers with a total power consumption of 2.75 W, further verifying the practical application value.

Two-Mode Controlled Single/Dual-Input DC–AC Inverter With Wide-Range DC Input

This article presents a two-mode controlled step-up inverter (TMCSI), which is capable of handling single or dual inputs with a wide range of dc input voltage. In comparison to traditional multistage dc/dc power conversion systems, the power conversion stage is reduced and the voltage/current stress of device is significantly alleviated without using high-voltage dc-bus capacitors. As a result, the reliability and overall conversion efficiency are improved accordingly. By combining the two working modes, the proposed inverter achieves uniform distribution of duty ratio under single/dual-input with a wide range of input voltage, and thereby is very suitable for systems having large input voltage variation. Moreover, based on the dual-input TMCSI, a novel power allocation method is also proposed to improve the system load-bearing ability. The power allocation method is controlled separately from two working modes that allows the two-input sources directly supply the ac load simultaneously. In this article, topology derivation, two-mode control strategy, characteristics of steady principle, and design criteria for the key circuit parameters are systematically analyzed, and important conclusions are obtained. Finally, the experimental results from the single/dual-input 500 VA 96-192 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">dc</sub> input and 220 V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">ac</sub> /50 Hz output inverter prototype verify the effectiveness of the proposed TMCSI topology and its associated power regulation approach.

Step‐Up seven‐level neutral‐point‐clamped inverter based topology for TL‐PVS

Single-phase transformerless inverters are widely installed in grid connected photovoltaic systems due to their outstanding advantages, namely, high efficiency, low cost and high power density. The lack of galvanic isolation leads to common-mode voltage (or current) issues, which are solved by means of modifications to topologies, control schemes and modulation strategies. This study proposes a novel multilevel inverter for single-phase transformerless photovoltaic systems. The topology is based on the neutral-point-clamped inverter, and is aimed to attenuate the leakage ground current. The latter is caused by the common-mode voltage fluctuations affecting the stray capacitances formed between the photovoltaic cells and the grounded frame. On the one hand, the proposed multilevel inverter can synthesise a seven levels output voltage, which reduces the total harmonic distortion. On the other hand, the magnitude of the output voltage can reach up to 1.5 times the DC input voltage, which eliminates the need of a voltage-boosting stage for grid interconnection. This study also presents three dedicated pulse-width modulation strategies, all of them based on the level-shifted multicarrier sinusoidal pulse-width modulation scheme. Numerical simulations and experimental tests in a 1 kW setup have been performed to evaluate the performance of the proposed topology

Novel multi‐level inverters with flyback high frequency link

A novel topological family of multi-level inverters with flyback high frequency link is proposed in this study. The inverters can transfer high DC voltage into regulated sinusoidal voltage with low total harmonic distortion (THD). The circuit configuration consists of high DC input voltage, DC-link capacitors, novel multi-level conversion unit, high frequency flyback transformer, cyclo-converter, output filter capacitor and AC load. This topological family includes diode-clamp type full-wave mode, hybrid-clamp half-bridge mode, multi-end mode and improved multi-end mode. To achieve reliable multi-level inversion and overcome DC-link capacitor voltages unbalance, multi-carrier modulation and DC-link capacitor voltage balancing strategy are presented. In addition, steady principle and AC small-signal model are analysed. Simulation and experimental results are given to prove that the novel flyback high frequency isolated multi-level inverters have the following advantages such as the high frequency electrical isolation, the bi-directional power flow, the two-stage power conversion (DC-high frequency AC (HFAC) - low frequency AC (LFAC)), the lower voltage stress of power switches and the low THD of output voltage.

Three-Phase Sinusoidal Output Buck-Boost GaN Y-Inverter for Advanced Variable Speed AC Drives

Motor drive systems supplied by a fuel-cell/battery are especially demanding when it comes to the design of the inverter. Besides a high performance (high efficiency <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\eta }$ </tex-math></inline-formula> and power density <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\rho }$ </tex-math></inline-formula> ), the inverter has to cope with the wide dc voltage variation of the fuel-cell/battery that supplies the motor drive. A promising three-phase inverter topology, denoted as Y-voltage source inverter (VSI), is presented in this article. The Y-VSI is a modular three-phase inverter and comprises three identical phase-modules connected to a common star “Y” point. Each phase-module is equivalent to a buck-boost dc/dc converter, which allows the ac output voltages to be higher or lower than the dc input voltage. Thereby, the Y-VSI effectively copes with the wide variation of the fuel-cell/battery voltage. Each phase-module can be operated in a similar fashion to a conventional dc/dc converter, independently of the remaining two phases. Accordingly, a straightforward and simple operation/control of the Y-VSI is possible. In addition, the Y-VSI features an integrated output filter. This allows for continuous/sinusoidal motor voltage waveforms, eliminating the need for an additional filter between the inverter and the motor. This article details the operating principle of the Y-VSI and comparatively evaluates two modulation strategies. In order to validate the proposed concepts, a Y-VSI hardware prototype is assembled within the context of a high-speed motor drive. In the investigated drive system, a fuel-cell supplies the Y-VSI, which in return controls a 280-kr/min 1-kW electric compressor. The Y-VSI hardware prototype is compared against a state-of-the-art hardware prototype, which features two energy conversion stages. It is shown that the Y-VSI is <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\Delta \eta = +2.3 \%}$ </tex-math></inline-formula> more efficient and at the same time <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">${\Delta \rho = +10 \%}$ </tex-math></inline-formula> more power-dense compared with the conventional inverter solution.

Investigation on performance of solar photovoltaic fed hybrid semi impedance source converters

Normally the output voltage of the solar photovoltaic panel is very low; it varies widely under the influence of environment and climatic conditions. In this paper the combination of each power system and the output of the dc-dc converters are regulated by some kind of increased dc input voltage. The structure of the dc-dc converter is also very important for photo voltaic power systems. Various voltage raising technologies have indeed been thoroughly tested to date, such as rectifier circuit, managed to switch inductance, capacity to change, coupled inductance, impedance matching, and spiralled raising technologies. However, these processes are both dynamic with poor accuracy and greater cost. The effectiveness of the hybrid semi impedance source converter is greater.

Analysis and Design of Quadratic Following Boost Converter

A boost converter which closely follows the quadratic converter voltage gain is proposed in this article. At tradeoff duty ratios, this converter is able to boost a lower input dc voltage to higher values at load side, higher than the traditional boost converter. This article also proposes a double-loop voltage-mode controller (DLVMC) for load voltage regulation, which exhibits better reference tracking as well as robust performance over the conventional proportional-integral-derivative (PID)-type robust controller. Also, addition of load voltage forward term suppresses the sensitivity and stability issues. An analytical and graphical approach is established to formulate the stabilizing region for the DLVMC parameter set. Parameter-space approach is the basis for the evolution of all possible controller parameter stabilizing regions. Furthermore, guaranteed combined sensitivity and guaranteed up–down glitch margin-related multiple performance constraints are simultaneously adopted in addition to absolute stability. As a result, any parameter combination corresponding to these stabilizing regions definitely ensures the proposed closed-loop converter system stability with sufficient robustness. An optimization methodology using integral time square error performance index is adopted to arrive at the optimal parameter set for DLVMC belonging to robust stabilizing regions. In order to assess the efficacy of the proposed robust controller design technique, a 75-W laboratory prototype is designed for experimentation. The DLVMC effectiveness in terms of load voltage regulation against the load and source perturbations along with reference tracking features is demonstrated experimentally. To also highlight its performance improvements, dynamic responses are compared and illustrated with the sample PID controller dynamic performance characteristics.

Harmonic minimization of a single-phase asymmetrical TCHB multilevel inverter based on nearest level control method

Multilevel inverters are gaining special interest among researchers and in the industry due to their widespread applications and numerous merits. Obtaining high quality, more reliable output while using a reduced number of electronic components is the main purpose of most of the research conducted in this area of study. The purpose of this study is to apply the nearest level control (NLC) method to a 13-level transistor-clamped H-bridge (TCHB) inverter with unequal DC voltage supplies. The NLC method operates at the fundamental frequency, thus reducing switching losses, and can reduce the harmonic content significantly. The adopted multilevel inverter consists of two TCHB cells supplied with two asymmetrical DC input sources with a voltage ratio of 1:2. This structure reduces the number of electronic components, and the asymmetry in the DC input voltages results in a higher number of levels. The adopted topology and its proposed control method were simulated in Matlab/Simulink, and the simulation results were verified through experiments using an Altera field-programmable gate array (FPGA) board. The results showed that the topology and its control method are efficient in obtaining a high-quality output with an improved total harmonic distortion (THD).

Design and analysis of a novel quasi Z source based asymmetric multilevel inverter for PV applications

A novel Quasi Z source (QZS) based Asymmetric Multilevel Inverter for Photovoltaic application is proposed in this paper. It consists of an Impedance source-based dc-dc converter and Asymmetric Multilevel Inverter (AMLI). QZS network can buck/boost the input DC voltage eliminating separate DC-DC boost converter. MLI topology with reduced switches and DC input provide high quality output with large levels. DC input magnitude of the inverter is based on an algorithm. The system ensures high voltage gain, low switching stress, lessened gate circuitry, high reliability and better harmonic profile. Low THD values ensures reduced filter size and hence cost. The theoretical concepts and parameter design of the proposed topology is illustrated in detail. The performance analysis is verified using Matlab/Simulink environment.

A Reduced Device Count Single DC Hybrid Switched-Capacitor Self-Balanced Inverter

Multilevel inverter (MLI) with switched-capacitor combinations have attained lots of attention for reducing the switch count, source count and control complexity. This brief discloses a cross-switched hybrid 13-level inverter (CHI) topology consisting of switched-capacitor circuits. The proposed CHI includes a single-dc source and only 12 switches to generate the 13-level triple voltage boost output. The desired output voltage levels are realized by self-balanced operation of the capacitors. The voltage across two capacitors is inherently maintained at input dc voltage (V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</sub> ) and other two capacitors are self-charged to 0.5V <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">in</sub> , which reduces the control complexity. Comparative assessment with prior-art MLIs indicates the merits such as fewer devices and low voltage stress of proposed CHI. To ascertain the operational principles simulation and experimental results are finally acquired under several steady and dynamic conditions.

Operational Principles of Three-Phase Single Active Bridge DC/DC Converters Under Duty Cycle Control

Single active bridge (SAB) dc/dc converters are attractive options for unidirectional dc/dc conversion in future medium power generation applications, offering galvanic isolation and a diode-based output side. SAB dc/dc converters must be controlled by adjusting the active bridge switching duty cycle, unlike dual active bridge converters where the phase-shift angle control is normally used. This article presents a comprehensive analysis of the operational principles of three-phase SAB dc/dc converters that arise from different duty cycle operation ranges. Moreover, the converter performances such as transformer harmonic currents are analyzed and compared between different input and output dc voltage conditions. Finally, an experimental validation using a small-scale prototype is presented.

Example of Inrush Current Elimination After Connection of High Input DC Voltage

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Application of new algorithms on asymmetric cascaded multilevel inverter

Purpose Multilevel inverter (MLI) is an established design approach for inverter applications in medium-voltage and high-voltage range of applications. An asymmetric design synthesizes multiple DC input voltage sources of unequal magnitudes to generate a high-quality staircase sinewave comprising a large number of steps or levels. However, the implications of using sources of unequal magnitudes results in the requirements of a large variety of inverter switches and higher magnitudes of the total blocking voltage (TBV) rating of the inverter, which increase the cost. The purpose of this study is to present a solution based on algorithms for establishing DC source magnitudes and other design parameters. Design/methodology/approach The approach used in this study is to develop algorithms that bring an asymmetric cascaded MLI (ACMLI) design close to symmetric design. This approach then reduces the variety of switch ratings and minimizes the TBV of the inverter. Thus, the benefits of both asymmetric design (generation of a large number of voltage levels in the output waveform) and symmetric design (modularity) are achieved. The proposed algorithms can be applied to a number of ACMLI topologies, including classical cascaded H-bridge (CHB). The effectiveness of the proposed algorithms is validated by simulation in Matlab-Simulink and experimental setup. Findings Two new algorithms are proposed that reduce the number of variety of switches to just three. The variety can further be reduced to two under a specified condition. The algorithms are compared with the existing ones, and the results are promising in minimizing the TBV rating of the inverter, which results in cost reduction as well. For a specific case of four CHBs, the proposed Algorithm-1 produced 27% and Algorithm-2 produced 53% higher levels. Moreover, the presented algorithms produced minimum values of the TBV and resulted in minimum cost of inverter. Originality/value The proposed algorithms are novel in structure and have achieved the targeted values of minimized switch variety and reduced TBV ratings. Due to less variety, the inverter achieves a near symmetric design, which enables to attain the added advantages of modularity and reduced difference of power sharing among the DC sources.

Sistem Pengujian Tegangan Boost Converter Pada Pembangkit ListrikTenaga Air (PLTH) Picohydro Kapasitas Rendah

Voltage testing, on hybrid power plants (PLTH), uses two sources that are solar/solar power plants and waterwheel power plants. Supporting components to produce electric energy conversion one of them is boostconverter which is the main subject. Therefore the author is interested in making and testing the voltage, on the boost converter with the aim to maximize the performance of the DC Genertator as a pensupplay Batterai/accu on PLTH Pico Hydro. The DC-voltage source of the DC-DC converter can be obtained from a generator, or an AC voltage source that is air-conditioned to DC. While Dc-DC converter is a power electronic circuit, to convert a DC to DC voltage input into the output voltage with a greater value. The test results of the voltage from the field data can be concluded as follows. The voltage boost converter test results, on the Pico Hydro Hybrid power plant can produce a voltage of 13 volts from the output DC Generator 8.39 Volt. The output voltage generated by the boost converter is 13.4 volts, can be stable although the output voltage of the generator is variable. With the addition of the tool boost converter on PLTH Pico Hydro, can help battery charging/ACCU to charge the required voltage of the battery is 12 volts, from the boos convevter 13.4 volt long time charging ACCU 5.3 hours.

Cascaded single-phase, PWM multilevel inverter with boosted output voltage

Splitting of a dc voltage source with two capacitors has been the approach in generating 5-level output voltage with single- and three-phase full-bridge circuits and added bidirectional switch. Associated with this configuration is the problem of voltage imbalance between the splitting capacitors. In addition, the inverter output voltage magnitude is obviously limited to the value of the split input voltage source. Presented in this paper is a unit topology for single-phase 5-level multilevel inverter, MLI. It simply consists of a full-bridge circuit, a capacitor, charge-discharge unit and a dc source. The charge-discharge unit with the capacitor is the interface between the full-bridge and the dc source. The proposed unit cell can generate a 5-level output voltage waveform whose peak value is twice the input voltage value. For higher output voltage level, a cascaded structure of the developed unit cell is presented. Comparing the proposed inverter with CHB inverter and some recent developed MLI topologies, it is found that the proposed inverter configuration generates higher output voltage value, at reduced component-count, than other topologies, for a specified number of dc input voltages. For two cascaded modules, simulation and experimental verifications are carried out on the proposed inverter topology for an R-L load.&#x0D; Keywords: Cascaded multilevel, Inverter, total harmonic distortion, topologies, waveform