Output Voltage Of Converter Research Articles

Methods and techniques of synchronous multi-zone modulation for the control of power electronic converters

This paper presents a short survey of the results of elaboration and investigation of novel methods, schemes, and algorithms of synchronous multi-zone space-vector modulation of signals in power electronic converters of electrical energy parameters, focused on improvement of operation efficiency of converter-based transport-oriented electric drives and of photovoltaic power conversion systems, which were published mainly in the two-year period 2019–2020. These methods and algorithms of synchronous pulse-width modulation (PWM) allow providing continuous synchronization and symmetries of waveforms of the converters output voltage, with minimization of undesirable sub-harmonics in spectra of voltage and current, and also with minimization of undesirable common-mode voltage in electric transport systems and in photovoltaic systems, which leads to corresponding loss reduction and efficiency increasing of these systems.

Modeling and Simulation of a Double-Stage Single-Phase Grid-Connected PV System

This paper presents the design model and simulation of a double-stage single-phase grid-connected PV system. This system includes an MPPT DC-DC boost power converter and a transformer-less single-phase DC-AC power inverter, which is connected to the power grid with an LCL filter. In the DC-DC boost converter, the Perturb and Observe algorithms are combined. The output voltage of the DC-DC converter is regulated, and the DC/AC output voltage is synchronized with the grid. The MATLAB-Simulink environment is used for the closed-loop simulation of the proposed setup. The simulation results are presented for various solar irradiance conditions and show that photovoltaic current is generated and matches the phase of grid voltage.

Optimized Weight Point ADF using SOS Algorithm

Active dc filter (ADF) has become the most viable alternatives for the compensation of the harmonics in the power system analysis. These filters are capable enough to minimize the total harmonic distortion (THD) and provide compensation towards the power quality issues appearing in the transmission system. A simulated model of a HVDC system is designed in MATLAB and the disturbance is injected in the form of load change and the controller efficacy is checked. This paper basically deals with the operational characteristics of the active filter for specific voltage rating irrespective of load and used to reduce harmonics present in the output voltage of the HVDC converter when cascaded with the inverter. The gains of the ADF are optimized with Symbiotic Organism Search Optimization (SOS) with THD as a constraint.

Design and Simulation of LLC Resonant Converter for Hydrogen Production Based on Proton Exchange Membrane Electrolysis

This paper studies the relationship between the parameters in LLC resonant circuit based on the fundamental wave analysis method, analyzes the gain curve and the soft-switching conditions of the power tube, gives the selection method of the parameters k and Q and calculates the resonant component parameters. In this paper, a closed-loop frequency modulation control method is used to control the DC output voltage of the resonant converter. At the same time, mathematical modeling and analysis are carried out for the electrochemical model and thermal model of the proton exchange membrane (PEM) hydrogen production electrolyzer, and the Simulink simulation tool is used to complete the joint simulation of the PEM electrolysis model and the LLC resonant converter. The simulation results fully reflect the actual control process.

An Analysis-Supported Design of a Single Active Bridge (SAB) Converter

Currently, due to its various applications, the high-performance isolated dc-dc converter is in demand. In applications where unidirectional power transfer is required, the single active bridge (SAB) is the most suitable one due to its simplicity and ease of control. The general schematic of the SAB converter consists of an active bridge and a passive bridge, which are connected through a high-frequency transformer thus isolated. The paper summarizes the behavior of this converter in its three operation modes, namely the continuous, discontinuous, and boundary modes. Later, the features of this converter, such as its input-to-output and external characteristics are discussed. Input-to-output characteristics include the variation of converter output power, voltage, and current with an input control variable i.e., phase-shift angle, whereas the external characteristic is the variation of the output voltage as a function of output current. In this discussion, the behavior of this converter in its extreme operating conditions is also examined. The features of the characteristics are elucidated with the help of suitable plots obtained in the MATLAB environment. Afterward, the specifications of a SAB converter are given and, based on the results of the analysis, a detailed design of its electrical elements is carried out. To validate the features and the design procedures presented in this paper, a prototype is developed. An element-wise loss estimation is also carried out and the efficiency of the converter has been found to be approximately equal to 93%. Lastly, the test was executed on this prototype, confirming the theoretical findings concerning this converter.

Analysis of Control Methods for the Traction Drive of an Alternating Current Electric Locomotive

The analysis of operating conditions of traction drives of electric locomotives with asynchronous traction motors has been carried out. It was found that during operation in the output converter of an asynchronous motor, defects may occur, which leads to asymmetric modes of its operation. Models of a traction drive of an electric locomotive with asynchronous motors with scalar and vector control of the output converter are proposed, taking into account asymmetric operating modes. As a result of the simulation, the starting characteristics of the traction drive were obtained for various control methods both in normal and emergency modes of the drive. For the drive-in emergency mode, the following cases were investigated: the balance of the converter output voltages and the turn-to-turn circuit of 10% of phase A winding of the motor stator; imbalance of the output voltages of the inverter and an intact motor; imbalance of the output voltages of the converter and interturn short circuit of 10% of phase A winding of the motor stator. Comparison of the simulation results have shown that in emergency modes in the traction drive, the torque ripple on the motor shaft in the drive with vector control is 13% less, and in scalar control, the phase current unbalance coefficient is 22% less. The results of this work can be used to study the influence of the output converter control methods on the energy efficiency indicators of the traction drive of an AC electric locomotive.

Simulation Analysis and Experimental Study of Piezoelectric Power Generation Device Based on Shape Memory Alloy Drive.

In order to solve the problem of waste heat collection from energy consumption, a thermal energy generation device combining shape memory alloy and piezoelectric materials has been designed. The shape memory alloy is heated and deformed to drive the drive wheel continuously, and the impact wheel is deformed against the piezoelectric cantilever beam during the rotation of the drive wheel to generate electricity. In this paper, the impact force generated by the impact wheel and the output voltage of the piezoelectric cantilever beam during the rotation process are given. Finally, the experimental test shows that the larger the radius of the drive wheel, the lower the impact force of the wheel and the lower the output voltage of the piezoelectric cantilever beam; the larger the diameter of the shape memory alloy wire, the higher the impact force of the wheel and the higher the output voltage of the piezoelectric cantilever beam; the more teeth of the drive wheel, the higher the impact frequency of the piezoelectric cantilever beam and the higher the output voltage. The maximum output voltage of the thermoelectric converter is 14.2 V, when the drive wheel radius is 13 mm, the shape memory alloy wire diameter is 1 mm and the number of impact wheel teeth is 6. The new structural design provides a new structural model for waste heat recovery and thermal energy generation technology. The new structural design provides a new approach and idea for waste heat recovery and thermal energy generation technology.

Realization of Hardware-in-the-loop Simulator of Thyristor-based Power Electronics Converters

Hardware-in-the-loop (HIL) simulation is very popular in various fields such as aerospace, automotive industry, power engineering, etc. It is a technique used to develop and test different complex systems in real time. The HIL simulator can almost ideally replace a real physical device or system, during the phase of rapid prototyping of the control structures of that device or system. In this paper, the HIL simulator of various thyristor-based power electronics converters is proposed and experimentally verified. Except the HIL simulator, the regulator for the control of the mean and effective value of the converter's output voltage is also implemented.

Direct Current Motor Position Control by a Sliding Mode Controlled Dual Three-Phase AC-DC Power Converter

Direct voltage source (DC) and a DC/DC power converter can be used to control the position, speed or torque of a DC motor. In such an operational condition, a rectifier is needed to have a DC voltage source, if a three-phase voltage source is available only. The objective of this study is to replace a rectifier and DC/DC power converter with one AC/DC power converter such that its output would be equal to the voltage needed for control of DC motor. It is assumed that the control algorithm of a DC motor is selected, which means that the desired output voltage of the AC/DC converter as a time function or function of the motor state is known. First, the sliding mode methodology is applied to control the converter's three branches to make three-phase input current track source voltages multiplied by a time-varying gain. Then the gain is selected such that the converter output voltage is equal to the desired input of the DC motor. It is shown that this condition holds if the time-varying gain satisfies the first-order differential equation, which can be implemented as part of the controller. The application of the Lyapunov theory confirmed that the position regulation process has a stable equilibrium point at the origin and the time gain variation is bounded. The power efficiency is equal to one which is a desirable setting in the proposed controller. A numerical simulation demonstrates the application of the developed control methodology for both constant and time-varying angular position reference.

A Novel Modified Adaptive Controller Design for Non Negative DC–DC Converter Using Meta-Heuristic Algorithms for Bio Medical Hybrid Application

Purpose: Meta-heuristic (MH) methods are used to develop an adaptive sliding mode controller for a POEL converter. MH algorithms have been used to address a variety of engineering optimization problems. Which will use for Bio medical hybrid systems applications. Design/Methodology: Particle Swarm Optimization (PSO) approach is well known and it could expedite the convergence characteristic in numerous applications. By means of amending PSO parameters like, inertia mass, social and perceptive agents at every generation, Modern Parameter Improved Particle Swarm Optimization (MPIPSO) algorithm which is a more enhanced version of PSO is developed. Findings: Since the converter output voltage’s integral squared error (ISE) has been chosen as a neutral function, the optimal PI controller design may be expressed in terms of optimization problems. Originality/Value: The superiority of the proposed MPIPSO based sliding mode controller has been shown by comparing the results with other existing MH optimization methodologies.

Analysis and Design of High-Efficiency Modular Multilevel Resonant DC-DC Converter

This paper demonstrates a high-efficiency modular multilevel resonant DC-DC converter (MMRC) with zero-voltage switching (ZVS) capability. In order to minimize the conduction loss in the converter, optimizing the root-mean-square (RMS) current flowing through switching devices is considered an effective approach. The analysis of circuit configuration and operating principle show that the RMS value of the current flowing through switching devices is closely related to the factors such as the resonant tank parameters, switching frequency, converter output voltage and current, etc. A quantitative analysis that considers all these factors has been performed to evaluate the RMS current of all the components in the circuit. When the circuit parameters are carefully designed, the switch current waveform can be close to the square waveform, which has a low RMS value and results in low conduction loss. And a design example based on the theoretical analysis is presented to show the design procedures of the presented converter. A 600 W 48 V-to-12 V prototype is built with the parameters obtained from the design example section. Simulation and experiments have been performed to verify the high-efficiency feature of the designed converter. The measured converter peak efficiency reaches 99.55% when it operates at 200 kHz. And its power density can be as high as 795 W/in <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> .

Active Voltage Balancing Control of a Seven-Level Hybrid Multilevel Converter Topology

The series connection of a standard three-level active neutral-point-clamped (ANPC) inverter and two cascaded H-bridge (CHB) modules comprising the flying capacitors (FCs) instead of the isolated dc voltage sources forms a seven-level hybrid topology that is referred to as improved ANPC (I-ANPC) converter. This article proposes an active voltage balancing technique for control of this hybrid multilevel inverter. The suggested method is based on a set of effortless logic equations that aim to stabilize the FC voltages within the CHB modules at their requisite reference values as well as to control the output voltage of the overall hybrid converter based on the phase-shifted-carrier pulsewidth modulation strategy. The experimental results obtained from a single-phase I-ANPC inverter's prototype are presented to validate the proposed control technique and its simple logic equations.

Single-Input Dual-Output Three-Level DC–DC Converter for EV

This paper presents the development of a non-isolated single-input dual-output three-level dc–dc converter (SIDO-TLC) appropriate for medium- and high-voltage applications. 3 level Buck-Boost converter is used in order to achieve the controllable output voltages. The main merits of this project include reducing voltage stress across semiconductor devices, improving efficiency, and reducing passive components size. This converter shows very good stability, even under simultaneous step changes of the loads and input voltage. Simulation analysis of converter output voltages for various duty cycles is presented for three cases of duty cycle control range.

Design of High-Frequency ZVS Full-Bridge Power Converter for Photovoltaic Applications

This paper presents the design of a high-frequency Zero Voltage Switching (ZVS) full-bridge converter with a phase-shifted driving signal for photovoltaic applications. According to the rapid development of power electronics technology, the smart power converter could provide high-power capacity with the high-frequency operation and achieve high energy delivery to the load. This power converter could also reduce the size of the transformer compared to the same power rating. The transformer has been developed using resonant technique and selecting the optimal switching frequency whereby the power converter could reduce switching loss and improve the system efficiency. The phase-shifted modulation switching technique has been selected to drive the power semiconductor switches of a full-bridge power converter based on the switching loss minimization method. The desired output voltage has been controlled using a closed-loop controller under a loop gain stability margin. The simulation results have showed that the output voltage could be controlled to the desired constant when the input voltage has changed from 370 VDC to 400 VDC. The output voltage of the power converter could be controlled at a constant of 24 VDC. Therefore, the proposed study has showed the effectiveness of the phase-shifted ZVS full-bridge power converter for photovoltaic applications such as the battery charging system. This power converter could operate at the desired voltage system and reduce the sizing of the power converter under high-performance efficiency.

Robust nonlinear control of a quasi‐resonant DC‐DC converter with turn‐on and turn‐off zero current switching

In this paper, a new robust control strategy is proposed to regulate the output voltage of a quasi-resonant converter. The proposed approach completely eliminates the switching losses and the electromagnetic interferences due to high current changing rates. The circuit structure is simple and affordable and does not have many auxiliary switches. The regulated output voltage of a buck converter must be robust to input voltage variations. Moreover, the controller must be robust to the circuit parameter uncertainties. In this paper, a new control strategy with nonlinear structure is used with the advantage of robustness, and turn-on and turn-off zero current switching. The robustness of the converter to the input voltage variations and the parameter uncertainties is investigated. The new proposed control strategy can be implemented using different controller types. Therefore, a comparison between the proposed nonlinear controller and a conventional PI controller, which is most widely used in practice, is performed. The simulation results show the efficiency and robustness of the proposed method. Finally, the simulation results are verified by the experimental tests.

An Adaptive Backstepping Sliding Mode Cascade-Control Method for a DC Microgrid Based on Nonlinear Virtual Inertia

In order to improve the bus voltage robustness of distributed multi-source DC microgrid, a new cascade control method based on nonlinear virtual inertia and adaptive backstepping sliding mode is proposed. Firstly, the mathematical model of distributed multi-source DC microgrid with a buck–boost interface converter is analyzed and established. A nonlinear virtual inertia control method based on a variable droop coefficient is given by introducing the converter output voltage variation rate feedback term and a saturation function equation. Secondly, the voltage and current double closed-loop cascade controller is designed by using backstepping sliding mode control and adaptive algorithms. Finally, the system and cascade control models are built in MATLAB/Simulink for multi-case simulation. The feasibility and effectiveness of the proposed method is verified by comparing the results with traditional control methods.

Optimal Design Methodology on Compensation Parameters of Inductive Power Transfer Converter for Electric Vehicles

Compensation topologies of the inductive power transfer (IPT) converter for electric vehicles (EVs) have been researched in previous works. However, a methodology for designing a compensation topology based on the efficiency of the IPT converter has been barely discussed. This paper proposes an optimal design methodology for compensation parameters to achieve optimal efficiency of the IPT converter with LCC-S. The optimal output voltage is derived using the losses analysis of the IPT converter, and the IPT converter is designed for the optimal output voltage to achieve the optimal efficiency. Furthermore, the battery management (BM) converter on the receiving side is designed based on the output voltage of the IPT converter, the fluctuation range of the coupling coefficient, and the battery charging voltage. The validity of the proposed IPT converter design methodology is verified by designing different compensation parameters and BM converters. The power rating of the three design cases is 3.3 kW with the same magnetic pads satisfying the SAE J2954 WPT 1 class.

A new level Increased NLM method of modular multi-level converters for reducing THD of output voltage

ABSTRACT This paper proposes a new modified level, increased nearest level modulation (NLM) method to improve the THD quality and enhance the quality of output voltage of modular multilevel converters (MMCs). Offshore wind farm links need connections from onshore national grids, and this paper is consistent with higher level voltage generation techniques by using MMC. By changing the on-number sub-modules (SM) at the middle position after using the round function, the generated gate logic by using the proposed method maintains a fixed magnitude value of phase voltage with a maximal number of (2 N + 1) levels, where N is the number of sub-modules per arm. The proposed method maintains the advantages of the conventional NLM such as simple implementation and low switching loss and avoids the disadvantages of the existing NLM method such as capacitor voltage ripple, peak value of arm inductor voltage, complexity in topology, etc. Both the advantages and disadvantages of the proposed and the conventional schemes are also studied, and an illustrated comparison shows the THD result differences for four methods. The system is simulated using MATLAB-Simulink to validate the feasibility of the proposed scheme and carried out by a hardware-in-the-loop simulation (HILS) system. By reviewing the simulation and experimental results, it was found that the proposed scheme improves the output voltage and THD quality.

A Power Factor Corrected Resonant EV Charger Using Reduced Sensor Based Bridgeless Boost PFC Converter

A reduced sensor based bridgeless boost (BLB) power factor correction (PFC) converter fed full-bridge inductor–inductor capacitor (FBLLC) converter for electric vehicle (EV) charging, is presented in this article. This converter is a twin stage converter, where the first stage is a PFC-BLB converter operating in continuous conduction mode of its boost inductors, and the second stage is an FBLLC converter, which converts the output voltage of the PFC-BLB converter to an isolated low voltage for constant current/constant voltage (CC/CV) charging of an EV battery. The BLB converter is switched at fixed frequency using pulsewidth modulated control, whereas FBLLC converter employs a pulse frequency modulation control to enable CC/CV charging of EV battery. An experimental prototype of EV charger is developed and the digital control of PFC-BLB and FBLLC converter, is implemented using a 32 bit <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$TMS320F28035$</tex-math></inline-formula> digital signal processor to charge an EV battery with a maximum power of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$2.7\text{ kW}$</tex-math></inline-formula> and a current of <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$50\text{ A}$</tex-math></inline-formula> .

Nonlinear Controller for the Set-Point Regulation of a Buck Converter System

In this paper, we present a nonlinear PID controller based on saturation functions with variable parameters in order to regulate the output voltage of a buck converter in the presence of changes in the input voltage. The main feature of the proposed controller is to bound the control input with a variable parameter to avoid the windup effect generated by the combination of the integral control action and some operation conditions. The main advantages of the proposed nonlinear PID controller are its low computing cost and the simple tuning task to implement the control strategy in an embedded system. The acceptable behavior of the closed-loop system is presented through the simulation and experimental results.