Model Of Power Converter Research Articles

A Modified Algorithm for the L/C-based Switch Model of Power Converters in Real-Time Simulation Based on FPGA

A Modified Algorithm for the L/C-based Switch Model of Power Converters in Real-Time Simulation Based on FPGA

Thermoelectric energy harvesting associated with heat pipes for monitoring highways weather conditions

This work aims to develop a prototype for autonomously monitoring highway weather conditions using thermoelectric energy. The prototype utilizes solar thermal energy, heat absorbed by the asphalt and soil heat to generate, convert, manage, and store energy. The study investigates the optimal functioning of the thermoelectric generator, including utilizing the soil as a heat sink and incorporating passive thermal control devices like heat pipes. A commercial ultra-low power converter model LTC3108 was experimentally tested for efficient energy conversion. The monitoring system is designed to acquire readings from sensors measuring relevant climate parameters such as temperature, atmospheric pressure, and humidity, focusing on ultra-low power characteristics. The acquired data is transmitted via LoRa technology to a server for processing and analysis. The prototype generated 286.24 J of energy with a maximum temperature gradient of 4.25 ºC in the thermoelectric generator. The energy cost of transmitting a 40-byte message through the LoRaWAN module was 0.625 J. The proposed climate data acquisition circuit had a theoretical consumption of 17.69 J. Experimental tests with the LTC3108 converter, and a 0.22 F supercapacitor demonstrated successful data transmission. This work provides a solid foundation for future studies utilizing thermoelectric energy in highway applications, resulting in a prototype suitable for real-world road scenarios.

Full state observer-based pole placement controller for pulse width modulation switched mode voltage-controlled buck Converter

Switched mode DC-DC converters play an important role in today's renewable energy systems, electric Vehicles, consumer electrical appliances, and many more. While many researchers have designed controllers for DC-DC converters, achieving low implementation cost remains a significant hurdle. This paper proposes a cost-effective observer-based pole placement controller for a PWM voltage-controlled Buck converter with clear step by step design approach. The state space averaged model of the DC-DC power converter is used to design pole placement with integrator compensator and full state observer. Pole placement is employed to improve the transient and steady state behavior of Voltage reference tracking response and full state observer is applied to extract the inductor current with the aim of removing the actual current sensor. Design specifications are set to a settling time of less than 5 msec and an overshoot of less than 5 %. While designing Observer-Controller combination, the separation principle, designing the controller and observer independently, is utilized by placing the observer poles far to the left of the controller poles for the Observer to converge faster. The designed controller and observer is verified with simulation in MATLAB/SIMULINK software and design of developed controller and observer are realized using low-cost analog electronics circuit components The results shows that the proposed system's strength in tracking the reference output voltage even in the presence of input voltage disturbance and the mean value of inductor current is well extracted having only the output voltage and MOSFET gate signal.

Real-Time Digital Mapped Method for Sensorless Multitimescale Operation Condition Monitoring of Power Electronics Systems

Operation condition monitoring of power electronics systems can improve analysis visibility for device administrators and researchers. However, the current sensor-based monitoring methods have limitations in accurately monitoring variables at multi-timescales. This article presents a real-time digital mapped (RTDM) method for the sensorless multi-timescale operation condition monitoring in power electronics systems using FPGA simulators. The mathematic models of power converters are deployed in the simulator considering multi-timescale characteristics. Both the digital simulator and the physical power converter are controlled by the same control signals, allowing the simulator to map the accurate operation conditions of the power converters without additional physical sensors. The RTDM method can monitor variables on the switching period timescale to the system transient timescale due to the consideration for the ideal switch modeling of the semiconductor switch. The effectiveness of the proposed method is demonstrated using a 30kW DAB converter as an example, through the integration of an experimental prototype and a simulator to create an RTDM platform. This method offers an easy and sensorless way to monitor multi-timescale variables in power electronics systems, providing a more comprehensive and visual analysis of their operation.

Inclusion of higher-order terms in the border-collision normal form: Persistence of chaos and applications to power converters

The dynamics near a border-collision bifurcation are approximated to leading order by a continuous, piecewise-linear map. The purpose of this paper is to consider the higher-order terms that are neglected when forming this approximation. For two-dimensional maps we establish conditions under which a chaotic attractor created in a border-collision bifurcation persists for an open interval of parameters beyond the bifurcation. We apply the results to a prototypical power converter model to prove the model exhibits robust chaos.

Data-Driven Modeling With Experimental Augmentation for the Modulation Strategy of the Dual-Active-Bridge Converter

For the performance modeling of power converters, the mainstream approaches are essentially knowledge-based, suffering from heavy manpower burden and low modeling accuracy. Recent emerging data-driven techniques greatly relieve human reliance by automatic modeling from simulation data. However, model discrepancy may occur due to unmodeled parasitics, deficient thermal and magnetic models, unpredictable ambient conditions, etc. These inaccurate data-driven models based on pure simulation cannot represent the practical performance in physical world, hindering their applications in power converter modeling. To alleviate model discrepancy and improve accuracy in practice, this paper proposes a novel data-driven modeling with experimental augmentation (D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> EA), leveraging both simulation data and experimental data. In D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> EA, simulation data aims to establish basic functional landscape, and experimental data focuses on matching actual performance in real world. The D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> EA approach is instantiated for the efficiency optimization of a hybrid modulation for neutral-point-clamped dual-active-bridge (NPC-DAB) converter. The proposed D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> EA approach realizes 99.92% efficiency modeling accuracy, and its feasibility is comprehensively validated in 2-kW hardware experiments, where the peak efficiency of 98.45% is attained. Overall, D <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> EA is data-light and can achieve highly accurate and highly practical data-driven models in one shot, and it is scalable to other applications, effortlessly.

Modeling and Control Simulation of Power Converters in Automotive Applications

This research introduces a model-based approach for the analysis and control of an onboard charger (OBC) system for contemporary electrified vehicles. The primary objective is to integrate the modeling of SiC/GaN MOSFETs electrothermal behaviors into a unified simulation framework. The motivation behind this project stems from the fact that existing literature often relies on finite element method (FEM) software to examine thermal dynamics, necessitating the development of complex models through partial derivative equations. Such intricate models are computationally demanding, making it difficult to integrate them with circuit equations in the same virtual environment. As a result, lengthy wait periods and a lack of communication between the electrothermal models limit the thorough study that can be conducted during the design stage. The selected case study for examination is a modular 1ϕ (single phase) onboard computer (OBC). This system comprises a dual active bridge (DAB) type DC/DC converter, which is positioned after a totem pole power factor correction (PFC) AC/DC converter. Specifically, the focus is directed toward a 7 kW onboard computer (OBC) utilizing high-voltage SiC/GaN MOSFETs to ensure optimal efficiency and performance. A systematic approach is presented for the assessment and selection of electronic components, employing circuit models for the totem pole power factor correction (PFC) and dual active bridge (DAB) converter. These models are employed in simulations closely mimicking real-world scenarios. Furthermore, rigorous testing of the generated models is conducted across a spectrum of real-world operating conditions to validate the stability of the implemented control algorithms. The validation process is bolstered by a comprehensive exploration of parametric variations relative to the nominal case. Notably, each simulation adheres to the recommended operational limits of the selected components and devices. Detailed data sheets encompassing electrothermal properties are provided for contextual reference.

Generalized Envelope-Based Modeling of Single-Phase Grid-Connected Power Converters

Generalized Envelope-Based Modeling of Single-Phase Grid-Connected Power Converters

Random decision forest (RDF) and crystal structure algorithm (CryStAl) for uncertainty consideration of RES & load demands with optimal design of hybrid CCHP systems

This manuscript proposes a multi-objective random development mode of hybrid Combined Cooling, Heating, And Power (CCHP) system, supply configuration, enclosing a turbine, cooler/heater, battery and storage tank, and photovoltaic/thermal collectors. The proposed optimal strategy is consolidation of Random Decision Forest (RDF) and Crystal Structure Algorithm (CryStAl), hence it is called RDF-CryStAl technique. The Power center models of power converters along with storage devices are create by assuming the characteristics of non-design elements. The annual value rate falls when system confidence levels drop and uncertainty is used. The yearly value savings rate is shown to be highly sensitive to the price of fossil-fuels as a result of the sensitivity analysis of economic-frontiers based on important economic factors. As a result, the inversion of star-collectors includes a robust impact of the turbine.

Modeling and Prediction of Common Mode Electromagnetic Interference in GaN-Based Switching Power Converters

Behavioral models of common mode (CM) electromagnetic interference (EMI) are proposed herein for a GaN high-electron-mobility transistor (HEMT) synchronous buck converter. First, a CM noise model is developed using a linear equivalent circuit that consists of a voltage source, current source, and two noise impedances. The behavioral parameters of the CM model are then extracted by changing the input-side shunt impedances. A GaN HEMT buck converter setup is then built using switching frequencies of 100 kHz, 200 kHz, and 500 kHz to verify the validity of the CM EMI behavioral model. A comparison between the experimental and predicted results indicated that the proposed CM EMI model of GaN-based power converters was able to predict well the CM EMI current in the 150 kHz–30 MHz frequency range.

Bandwidth oriented approach for the design of a PI controller for a three phase two-stage grid-connected PV system

ABSTRACT The two-stage power converter is currently the most widespread topology for three-phase grid-connected photovoltaic (PV) systems. The PV power is injected to the grid through the regulation of the dc-link voltage. This method is commonly called the voltage control method, whereby the current is controlled indirectly. This paper focuses on the modelling of power converters and the parameter design of proportional-integral (PI) controllers, based on the bandwidth of the inner current loop and the outer voltage loop. It is assumed that the inner loop has a bandwidth that is ten-fold bigger than that of the outer loop, in order to fully decouple the dual loops. The PI parameters are thus determined through this relationship, and two sets of simulations are run to validate the methodology used. Results show that the controllers give highly satisfactory performance even in the presence of transients introduced by rapidly varying irradiance model.

State Feedback with Integral Control Circuit Design of DC-DC Buck-Boost Converter

The pulse-with modulated (PWM) dc-dc buck-boost converter is a non-minimum phase system, which requires a proper control scheme to improve the transient response and provide constant output voltage during line and load variations. The pole placement technique has been proposed in the literature to control this type of power converter and achieve the desired response. However, the systematic design procedure of such control law using a low-cost electronic circuit has not been discussed. In this paper, the pole placement via state-feedback with an integral control scheme of inverting the PWM dc-dc buck-boost converter is introduced. The control law is developed based on the linearized power converter model in continuous conduction mode. A detailed design procedure is given to represent the control equation using a simple electronic circuit that is suitable for low-cost commercial applications. The mathematical model of the closed-loop power converter circuit is built and simulated using SIMULINK and Simscape Electrical in MATLAB. The closed-loop dc-dc buck-boost converter is tested under various operating conditions. It is confirmed that the proposed control scheme improves the power converter dynamics, tracks the reference signal, and maintains regulated output voltage during abrupt changes in input voltage and load current. The simulation results show that the line variation of 5 V and load variation of 2 A around the nominal operating point are rejected with a maximum percentage overshoot of 3.5% and a settling time of 5.5 ms.

Design and Evaluation Framework for Modular Hybrid Battery Energy Storage Systems in Full-Electric Marine Applications

In the context of the maritime transportation sector electrification, battery hybridization has been identified as a promising manner of meeting the critical requirements on energy and power density, as well as lifetime and safety. Today, multiple promising battery hybridization topologies have been identified, while there is not a level playing field enabling comparison between different topologies. This study bridges this gap directly by proposing a generic hybrid battery energy storage system (HBESS) design and evaluation framework in full-electric marine applications that accounts for the key design requirements in the system topology conceptualization phase. In doing so, generalized key component models, such as battery cell models, aging models, power converter models, and thermal models, are established. Additionally, given the selected key requirements in this study, the case study comparing one baseline monotype design and two HBESS topologies has shown the clear advantage of battery hybridization. Furthermore, we find that, depending on the topology selection and the specific load scenario being considered, power converter devices can also worsen the key performance indexes.

Closed-Form Implicit Models for Efficient Simulation of Power Electronics

This document describes novel closed-form implicit (CF-implicit) models of switched-mode power converters, which feature implicit integration but require no iterative numerical solving algorithm for evaluation because they are explicitly solved in CF prior to model execution. The derived models capture the large-signal dynamic behavior of the power converters, so their use and accuracy are not limited to any one set of operating conditions. These models can be directly implemented in any computational environment, including directly on an existing embedded controller. Since no iterative solver is required, the models are highly computationally efficient and have a very predictable worst case execution time (WCET), which makes them especially suitable for real-time (RT) modeling applications, such as hardware-in-the-loop (HIL) simulation or digital twins (DTs). The model derivation process is demonstrated by example on a two-stage power converter, and computational expense is analyzed. A discussion of model error is also included.

A universal model for power converters of battery energy storage systems utilizing the impedance-shaping concepts

Battery energy storage systems (BESSs) render different services in microgrids (MGs) depending on the MG connection mode. In the grid-connected mode, the BESS optimally injects/absorbs power, operated by a power converter controlled as the grid-feeding voltage source converter (GFD-VSC). In the islanded mode, the BESS may work as distributed slack bus controlled by the grid-forming VSC (GFM-VSC). However, for performing with a desirable performance, the GFD-VSC and the GFM-VSC demand different grid characteristics. Specifically, the GFD-VSC has a grid-synchronization issue and may become unstable in weak grids with high inductive impedance. Contrarily, the GFM-VSC reveals better performance when connected to the MG through a feeder with high inductive impedance. Besides, switching between different operating modes may cause undesirable transients. This issue can be addressed by the impedance shaping concept that is realized through the control design of the power converter. However, there is limited flexibility for impedance shaping using conventional PI-based controllers. To this end, in this paper, a universal controller is proposed, which is developed based on the impedance shaping concept. Also, sliding mode control (SMC) is used to overcome the undesirable transients due to switching between operating modes. The effectiveness of the control structure is evaluated in islanded operation, under weak grid connection, and FRT transients in MATLAB/Simulink.

Nonlinear Behavioral Modeling and Real-Time Simulation of Electric Propulsion System for the High-Fidelity X-in-the-Loop Applications

The electric propulsion system (EPS) is an important enabling technology for electrified transportation. The short time-to-market of such a system relies on real-time simulation (RTS)-based efficient X-in-the-loop testing. To ensure high fidelity, the RTS should include the detailed behavior as much as possible while complying with the constraints of the model computing time. Therefore, a nonlinear behavioral real-time modeling approach is proposed for the EPS in this article, including the adaptive curve-fitting (ACF)-based device-level power electronics model and the nonlinear flux-linkage-based spatial harmonic (FLSH) PMSM model. The real-time models are designed and implemented on the NI FLEXRIO FPGA module. Ultralow RTS latencies are realized for the ACF power converter model and the FLSH PMSM model, which are 25 and 160 ns, respectively. The simulation accuracies are consistent with the off-line simulation tools. Moreover, the ACF model and the FLSH model are used in the RTS of a fuel cell electric vehicle (FCEV) EPS together with the generic fuel cell model, the battery model, and the vehicle dynamic motion model. The RTS results prove that the proposed EPS real-time model is an excellent candidate for RTS applications.

State-Space Modeling and Control of Grid-Tied Power Converters With Capacitive/Battery Energy Storage and Grid-Supportive Services

Advances in the fields of renewable generation, electric vehicles, and energy storage systems push forward the research on ac–dc and dc–ac grid-tied power converters. However, the variabilities of power converters create new challenges in modeling and control. Existing state-space models fail to accurately describe various types of grid-tied converters (GTCs), particularly those with grid-supportive services, which are increasingly required by upcoming grid codes. As such, this article first proposes to classify GTCs into four basic types according to their ac and dc characteristics. Subsequently, corresponding detailed state-space models of GTCs are introduced, which serve as a useful tool for stability analysis. On top of that, this article further proposes control implementations of grid-supportive services related to active and reactive power control, including droop, inertia, and oscillation damping. Finally, simulation and experimental results demonstrate the effectiveness of the proposed models and grid-supportive services.

Simplified Nonlinear Current-Mode Control of DC-DC Cuk Converter for Low-Cost Industrial Applications.

This paper presents a robust nonlinear current-mode control approach for a pulse-width modulated DC-DC Cuk converter in a simple analog form. The control scheme is developed based on the reduced-state sliding-mode current control technique, in which a simplified equivalent control equation is derived using an averaged power converter model in continuous conduction mode. The proposed controller does not require an output capacitor current sensor and double proportional-integral compensators as in conventional sliding-mode current controllers; thus, the cost and complexity of the practical implementation is minimized without degrading the control performance. The simplified nonlinear controller rejects large disturbances, provides fast transient response, and maintains a constant switching frequency. The nonlinear control scheme is developed using an analog circuit with minimal added components, which is suitable for low-cost industrial applications. The control law derivation, control circuit design, controller gains selection, and stability analysis are provided. The proposed control methodology is verified via simulating the closed-loop nonlinear power converter model in MATLAB/SIMULINK under abrupt changes in load current and input voltage. The simulation results show that the proposed control scheme provides robust tracking performance, a low percentage overshoot, fast transient response, and a wide operating range. The maximum percentage overshoot and settling time of the closed-loop power converter response during line disturbance are 5.6% and 20 ms, respectively, whereas the percentage overshoot and settling time during load disturbance are 2.8% and 15 ms, respectively.

АЛГОРИТМ ОПРЕДЕЛЕНИЯ ПАРАМЕТРОВ РЕГУЛЯТОРА, УДОВЛЕТВОРЯЮЩИХ ТРЕБОВАНИЯМ ПЕРЕХОДНОГО ПРОЦЕССА В ПОНИЖАЮЩЕМ ПРЕОБРАЗОВАТЕЛЕ ПОСТОЯННОГО НАПРЯЖЕНИЯ

The relevance Any modern simulator of an integral part of the spacecraft power supply system (SC PSS) is an energy-converting complex and is a continuous- discrete, non-stationary system with a variable structure. In order to fully simulate all modes of solar and storage batteries, as well as all types of electrical load, simulators must be developed consisting of several interconnected subsystems that form the overall structure of the simulator. During the tests, depending on the current mode of operation, one of the necessary (not in demand) subsystems at a given time is connected (disconnected), i.e. simulators are systems with a variable structure. Taking into account the power of the PSS of the spacecraft, simulators of the components of the PSS should have no less than the rated power, and therefore they must be created on the basis of power converters of electricity, since the latter have the best efficiency of possible energy-converting electrical systems. In addition, modern power conversion systems are impossible without the use of electronic computing tools — lower-level controllers and computers, on the basis of operating systems of which a fullfledged control software package is deployed. Thus, a modern simulator of the PSS component is a continuous-discrete impulse system. Taking into account the requirements for reliability and the period of active operation imposed on modern solar power plant simulators, it should be borne in mind that over long periods of operation, the parameters of electronic components degrade, on the basis of which power converters are built. Thus, the simulators of the PSS components of the spacecraft are non-stationary systems with long periods of active operation. Thus, at present, it is relevant to consider approaches to determining continuous linear models of power converters of electrical energy in order to synthesize the controllers of their control systems, which form the basis for constructing any simulator of an integral part of the PSS of a spacecraft. Aim of research To form a multilevel computer model of a DC converter and determine the values of the coefficients of the voltage and current PID controllers that provide optimal switching between its operating modes. Research methods Method of multilevel component chains, method of coordinate descent. Results In the format of the method of multilevel component circuits, a multilevel model is formed that provides the determination of the values of the parameters of the coefficients of the voltage and current PID controllers, at which the optimal switching between the modes of its operation is observed in the DC buck converter.

Active and Reactive Power Control in Transmission Line with PSO Optimized PI controlled Five Level UPFC

Abstract: In this paper, particle swarm optimization (PSO) optimized PI controlled five level UPFC is proposed for a double circuit transmission line. To enhance UPFC performance, a different approach is considered here. It uses simplified power system models to derive the decoupled power controllers, but detailed modeling of the UPFC power converters improves their ride-through capability. This paper introduces decoupled linear UPFC power controllers to obtain the reference ac voltages and currents for the two back-to-back-connected three-phase five-level NPC converters that enforce active and reactive power control in the transmission line. This paper proposes three main contributions to increase the dc-link voltage steadiness of multilevel UPFCs under line faults: 1) decoupled active and reactive linear power controllers; 2) real-time PWM generation; and 3) balancing of dc capacitor voltages. The MATLAB/SIMULINK model for the proposed circuit with PSO-optimized PI controlled five level UPFC is shown here with the results.