Energies

Editorial

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2 pages, 148 KiB

Open AccessEditorial

Control of Power Electronics Converters and Electric Motor Drives

by Federico Barrero and Jorge Rodas

Energies 2021, 14(15), 4591; https://doi.org/10.3390/en14154591 - 29 Jul 2021

Cited by 1 | Viewed by 1705

Abstract

With the increased emphasis on climate change and reducing harmful emissions in the atmosphere, interest in power electronics converters and electric motor drives has led to significant new developments in areas such as renewable energy systems or electric propulsion [...] Full article

(This article belongs to the Special Issue Control of Power Electronics Converters and Electric Motor Drives)

Research

Jump to: Editorial

14 pages, 4301 KiB

Open AccessArticle

Discrete Terminal Super-Twisting Current Control of a Six-Phase Induction Motor

by Yassine Kali, Maarouf Saad, Jesus Doval-Gandoy and Jorge Rodas

Energies 2021, 14(5), 1339; https://doi.org/10.3390/en14051339 - 1 Mar 2021

Cited by 12 | Viewed by 1975

Abstract

In this manuscript, the high-accuracy stator currents tracking issue is considered for a six-phase induction motor subject to external perturbations and uncertainties due to unmeasurable rotor currents and electrical parameter variations. To achieve the control goals, the common two-cascade controllers structure is required [...] Read more.

In this manuscript, the high-accuracy stator currents tracking issue is considered for a six-phase induction motor subject to external perturbations and uncertainties due to unmeasurable rotor currents and electrical parameter variations. To achieve the control goals, the common two-cascade controllers structure is required for this type of motor. The first controller in the outer loop consists of a proportional integral to regulate the speed. Then, the second is the proposed inner nonlinear stator currents controller based on a robust discrete-time terminal super-twisting algorithm supported by the time-delay estimation method. For the design procedure, the discrete-time stator currents dynamics are derived; for example, the vector of the matched perturbations and unmeasurable rotor currents are specified to simplify the estimation. A detailed stability analysis of the closed-loop error dynamics using Lyapunov theory is given. Finally, a real asymmetrical six-phase induction motor is used to implement in real-time the developed method and to illustrate its effectiveness and robustness. The results obtained reveal a satisfactory stator currents tracking in steady state and transient conditions and under variation in the magnetizing inductance. Moreover, a comparative study with an existing method in steady state for two different rotor speeds is presented to show the superiority of the proposed discrete-time technique. Full article

(This article belongs to the Special Issue Control of Power Electronics Converters and Electric Motor Drives)

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25 pages, 14875 KiB

Open AccessArticle

A New Robust Digital Non-Linear Control for Power Factor Correction—Arc Welding Applications

by Quentin Bellec, Jean-Claude Le Claire, Mohamed Fouad Benkhoris and Peyofougou Coulibaly

Energies 2021, 14(4), 991; https://doi.org/10.3390/en14040991 - 13 Feb 2021

Cited by 3 | Viewed by 1927

Abstract

A welding power source is commonly assimilated to a non-linear load. Arc welding market being in full growth, the resulting harmonic pollution is becoming an increasingly difficult problem to ignore. Therefore, the main purpose of this work is to define and implement the [...] Read more.

A welding power source is commonly assimilated to a non-linear load. Arc welding market being in full growth, the resulting harmonic pollution is becoming an increasingly difficult problem to ignore. Therefore, the main purpose of this work is to define and implement the most suitable solution for power factor correction in a welding power source. Due to the high non-linearity of the electric arc, the current controller used to control grid current need to show high robustness. Consequently, this paper focuses on the digitization of a very robust Phase-Shift Self-Oscillating Current Controller (PSSOCC), which only exists in its analog version until then, to carry out this task. After quick descriptions of the entire energy conversion chain and the PSSOCC operation principle, a model of the digital PSSOCC is proposed. Then, the quality and the accuracy of the aforementioned model are evaluated and its operating limits are identified. Afterwards, the behavior of the digital controller is studied within a Power Factor Correction (PFC) regulation for several specific arc welding operating modes. Finally, excellent robustness of this new FPGA-based digital current controller, named DPSSOCC, is confirmed on a three-phase Vienna converter test bench. Full article

(This article belongs to the Special Issue Control of Power Electronics Converters and Electric Motor Drives)

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15 pages, 6140 KiB

Open AccessArticle

Discrete Fundamental AC Voltage Controller for Three-Phase Standalone Converters

by Alejandro García-Fernández, Jesús Doval-Gandoy and Diego Pérez-Estévez

Energies 2021, 14(3), 650; https://doi.org/10.3390/en14030650 - 27 Jan 2021

Cited by 1 | Viewed by 1721

Abstract

Voltage control of standalone converters with LC filter is usually based on proportional-resonant or proportional-integral controllers, which often require further active damping methods to achieve stability. These solutions place design constraints in the selection of the closed-loop pole locations which limit the achievable [...] Read more.

Voltage control of standalone converters with LC filter is usually based on proportional-resonant or proportional-integral controllers, which often require further active damping methods to achieve stability. These solutions place design constraints in the selection of the closed-loop pole locations which limit the achievable bandwidth and increase the design complexity. In contrast, in state-space based controllers, the closed-loop poles can be placed freely through state feedback, which makes them particularly suitable for high order plants and/or low sampling frequencies. Among the modern control methods, direct pole placement is a simple technique that enables the establishment of a straightforward relationship between outcome and design, as opposed to more advanced approaches. This paper presents a discrete state-space voltage controller for standalone converters with LC output filter. The proposed method combines the direct pole placement technique with a virtual disturbance observer in order to compensate the effects produced by the load and model mismatches. The design process takes into account both the filter parameters and the sampling frequency, rendering the performance of the obtained controller independent of both. The result is a streamlined design procedure that leads to consistent outcomes for a wide range of plant parameter variations, requiring only one input: the desired closed-loop bandwidth. Full article

(This article belongs to the Special Issue Control of Power Electronics Converters and Electric Motor Drives)

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24 pages, 14486 KiB

Open AccessArticle

Interior Permanent Magnet Synchronous Motor Drive System with Machine Learning-Based Maximum Torque per Ampere and Flux-Weakening Control

by Faa-Jeng Lin, Yi-Hung Liao, Jyun-Ru Lin and Wei-Ting Lin

Energies 2021, 14(2), 346; https://doi.org/10.3390/en14020346 - 9 Jan 2021

Cited by 15 | Viewed by 3012

Abstract

An interior permanent magnet synchronous motor (IPMSM) drive system with machine learning-based maximum torque per ampere (MTPA) as well as flux-weakening (FW) control was developed and is presented in this study. Since the control performance of IPMSM varies significantly due to the temperature [...] Read more.

An interior permanent magnet synchronous motor (IPMSM) drive system with machine learning-based maximum torque per ampere (MTPA) as well as flux-weakening (FW) control was developed and is presented in this study. Since the control performance of IPMSM varies significantly due to the temperature variation and magnetic saturation, a machine learning-based MTPA control using a Petri probabilistic fuzzy neural network with an asymmetric membership function (PPFNN-AMF) was developed. First, the d-axis current command, which can achieve the MTPA control of the IPMSM, is derived. Then, the difference value of the dq-axis inductance of the IPMSM is obtained by the PPFNN-AMF and substituted into the d-axis current command of the MTPA to alleviate the saturation effect in the constant torque region. Moreover, a voltage control loop, which can limit the inverter output voltage to the maximum output voltage of the inverter at high-speed, is designed for the FW control in the constant power region. In addition, an adaptive complementary sliding mode (ACSM) speed controller is developed to improve the transient response of the speed control. Finally, some experimental results are given to demonstrate the validity of the proposed high-performance control strategies. Full article

(This article belongs to the Special Issue Control of Power Electronics Converters and Electric Motor Drives)

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18 pages, 6117 KiB

Open AccessArticle

LLC LED Driver with Current-Sharing Capacitor Having Low Voltage Stress

by Wen-Zhuang Jiang, Kuo-Ing Hwu and Jenn-Jong Shieh

Energies 2021, 14(1), 112; https://doi.org/10.3390/en14010112 - 28 Dec 2020

Cited by 2 | Viewed by 2086

Abstract

In this paper, an LLC light-emitting diode (LLC LED) driver based on the current-sharing capacitor is presented. In the proposed LED driver, the LLC resonant converter is used to step down the high input voltage, to provide galvanic isolation, to offer a constant [...] Read more.

In this paper, an LLC light-emitting diode (LLC LED) driver based on the current-sharing capacitor is presented. In the proposed LED driver, the LLC resonant converter is used to step down the high input voltage, to provide galvanic isolation, to offer a constant current for LEDs. Moreover, the current-sharing capacitor connected to the central-tapped point of the secondary-side winding is used to balance the currents in two LED strings. By doing so, the voltage stress on this capacitor is quite low. Above all, the equivalent forward voltages of the two LED strings are generally influenced by the temperature and the LED current, and this does not affect the current-sharing performance, as will be demonstrated by experiment on the difference in number of LEDs between the two LED strings. In addition, only the current in one LED string is sensed and controlled by negative feedback control, while the current in the other LED string is determined by the current-sharing capacitor. Moreover, this makes the current control so easy. Afterwards, the basic operating principles and analyses are given, particularly for how to derive the effective resistive load from the LED string. Eventually, some experimental results are provided to validate the effectiveness of the proposed LED driver. Full article

(This article belongs to the Special Issue Control of Power Electronics Converters and Electric Motor Drives)

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25 pages, 3817 KiB

Open AccessFeature PaperArticle

An Adaptive Model-Based MPPT Technique with Drift-Avoidance for Grid-Connected PV Systems

by Mostafa Ahmed, Mohamed Abdelrahem, Ibrahim Harbi and Ralph Kennel

Energies 2020, 13(24), 6656; https://doi.org/10.3390/en13246656 - 17 Dec 2020

Cited by 23 | Viewed by 2305

Abstract

In this article, a modified control structure for a single-stage three phase grid-connected photovoltaic (PV) system is presented. In the proposed system, the maximum power point tracking (MPPT) function is developed using a new adaptive model-based technique, in which the maximum power point [...] Read more.

In this article, a modified control structure for a single-stage three phase grid-connected photovoltaic (PV) system is presented. In the proposed system, the maximum power point tracking (MPPT) function is developed using a new adaptive model-based technique, in which the maximum power point (MPP) voltage can be precisely located based on the characteristics of the PV source. By doing so, the drift problem associated with the traditional perturb and observe (P&O) technique can be easily solved. Moreover, the inverter control is accomplished using a predictive dead-beat function, which directly estimates the required reference voltages from the commanded reference currents. Then, the reference voltages are applied to a space vector pulse width modulator (SVPWM) for switching state generation. Furthermore, the proposed inverter control avoids the conventional and known cascaded loop structure of the voltage oriented control (VOC) method by elimination of the outer PI controller, and hence the overall control strategy is simplified. The proposed system is compared with different MPPT techniques, including the conventional P&O method and other techniques intended for drift avoidance. The evaluation of the suggested control methodology depends on various radiation profiles created in MATLAB. The proposed technique succeeds at capturing the maximum available power from the PV source with no drift in comparison with other methods. Full article

(This article belongs to the Special Issue Control of Power Electronics Converters and Electric Motor Drives)

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13 pages, 4437 KiB

Open AccessArticle

Expansion of Operating Speed Range of High-Speed BLDC Motor Using Hybrid PWM Switching Method Considering Dead Time

by Ho-Jin Kim, Hyung-Seok Park and Jang-Mok Kim

Energies 2020, 13(19), 5212; https://doi.org/10.3390/en13195212 - 6 Oct 2020

Cited by 10 | Viewed by 3587

Abstract

In vehicle electrical systems with limited battery power, the output torque and speed of high-speed brushless DC (BLDC) motors can decrease due to unstable and reduced supply voltage or manufacturing errors in the motor back electromotive force (EMF). This paper presents a method [...] Read more.

In vehicle electrical systems with limited battery power, the output torque and speed of high-speed brushless DC (BLDC) motors can decrease due to unstable and reduced supply voltage or manufacturing errors in the motor back electromotive force (EMF). This paper presents a method that can guarantee the output performance of an inverter through a control algorithm without a separate power supply system and DC-link voltage increase. The proposed control algorithm can increase the output torque and speed of a high-speed BLDC motor by using appropriate selection and change of the inverter’s pulse width modulation (PWM) control method. In this paper, the operation and electrical characteristics of various PWM methods of BLDC motors are analyzed, and the optimal PWM method for improving the control performance of high-speed BLDC motors is presented. In addition, the relationship between the switching frequency, dead time, and voltage utilization was mathematically analyzed. Based on the results of this analysis, the proposed control algorithm automatically changes the PWM switching mode at the point where the output torque and speed need to be extended. The effectiveness and feasibility of the control method proposed in this paper is verified through the experimental results on the designed and manufactured high-speed BLDC motor system for vehicles. Full article

(This article belongs to the Special Issue Control of Power Electronics Converters and Electric Motor Drives)

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