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In recent years, wind power generation has been promoted as a countermeasure to global environmental problems. However, the introduction of many wind power generators into the power system may cause system frequency fluctuations. This paper proposes a control method to reduce system frequency fluctuations by using the rotor kinetic energy (RKE) of a variable speed wind turbine (VSWT). When the frequency falls, this method suppresses fluctuations by consuming RKE to increase VSWT power generation, and when it rises, it decreases VSWT power generation by accumulating RKE. The effectiveness of this method is confirmed through simulations using PSCAD/EMTDC. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract To solve the problem of oscillation instability in permanent magnetic synchronous generator (PMSG)-based wind power connected systems during low-voltage ride through (LVRT) process, a parameter adjustment strategy based on interaction energy path optimization is proposed in this paper. Firstly, a modular state-space model of PMSG under fault transient conditions is constructed, and the system is divided into five subsystems. Then, the dynamic energy function of subsystems reflecting the oscillation stability of the system is derived. Based on that, the dynamic energy flow path is described considering the introduction of LVRT control. On this basis, the interaction energy between LVRT control links and subsystems is analyzed, and the coupling mechanism of voltage support and damping characteristics in the LVRT process is explained. Further, aiming at the optimal change rate of the total interaction energy in the LVRT process, the adjustment strategy of LVRT control parameters is constructed to meet voltage and damping requirements. Finally, a PMSG-connected system model is built on the MATLAB/Simulink platform to verify the effectiveness of the adjustment strategy. The results show that the proposed method can effectively improve the damping level under the fault transient condition, as well as supporting system voltage.

To solve the problem of oscillation instability in permanent magnetic synchronous generator (PMSG)-based wind power connected systems during low-voltage ride through (LVRT) process, a parameter adjustment strategy based on interaction energy path optimization is proposed in this paper. Firstly, a modular state-space model of PMSG under fault transient conditions is constructed, and the system is divided into five subsystems. Then, the dynamic energy function of subsystems reflecting the oscillation stability of the system is derived. Based on that, the dynamic energy flow path is described considering the introduction of LVRT control. On this basis, the interaction energy between LVRT control links and subsystems is analyzed, and the coupling mechanism of voltage support and damping characteristics in the LVRT process is explained. Further, aiming at the optimal change rate of the total interaction energy in the LVRT process, the adjustment strategy of LVRT control parameters is constructed to meet voltage and damping requirements. Finally, a PMSG-connected system model is built on the MATLAB/Simulink platform to verify the effectiveness of the adjustment strategy. The results show that the proposed method can effectively improve the damping level under the fault transient condition, as well as supporting system voltage. [ABSTRACT FROM AUTHOR]

A local commodity, Yellow rasbora Rasbora lateristriata (Bleeker, 1854), can potentially be used as food by the Kulon Progo community. Added to that, aquaculture is known to optimize this potential and will also prevent illegal fishing where yellow rasbora are listed as a vulnerable species in the IUCN Red list. This study induced male yellow rasbora using the hormone OODEV® injection, which comprises Pregnant Mare Serum Gonadotropin (PMSG) and anti-dopamine. Yellow rasbora was nurtured to the age of six months and treated with four different treatments (dose) for a month, namely 0 mL/Kg, 0.25 mL/Kg, 0.5 mL/Kg, and 0.75 mL/Kg. Observed parameters included motility (movement and duration) as well as sperm count, sperm viability, sperm morphology, sperm morphometry, gonad somatic index (GSI), and survival rate (SR). Data obtained were analyzed using SPSS with the One-way ANOVA test and continued with Duncan's test if the results were significant. The obtained results had no significant effect on the IGS value. In addition, administration of OODEV® also improved sperm quality with the best results at 0.75 mL/Kg in terms of motility with the highest progressive movement compared to other doses but not significant compared to the control and significantly longer movement duration compared to other doses. In terms of morphometry and tail width, it was not significant compared to other doses, longest tail length but not significant with other doses except with 0.25 mL/Kg, and significantly had the longest sperm total length. Every dose showed a 100% percentage of survival rate. [ABSTRACT FROM AUTHOR]

In this work, an optimal control scheme based on the Maximum Power Point tracking for the Wind Energy Conversion System using Permanent Magnet Synchronous Generator (PMSG) is proposed and also modeled. The system studied in this paper consists of wind energy system powering a battery using a buck-boost converter as an interface. By modifying the buck-boost duty cycle, we vary the reflected voltage at PMSG, and accordingly its speed. It is controlled with Perturb and Observe (P&O) Maximum Power Point Tracking (MPPT) approach. The overall system is simulated with MATLAB/SIMULINK. [ABSTRACT FROM AUTHOR]

The grid interconnections for direct-drive wind farms have triggered multiple new sub-synchronous oscillation events, which can prevent the power system from operating safely and stably. However, the excessively high order of the detailed model for large-scale wind farms with multiple direct-drive permanent magnet synchronous generators (PMSGs) connected to power systems poses a challenge when investigating small disturbance stability and instability mechanisms. This study establishes a model of the grid-connected PMSG system based on the voltage/power excitation–response relationship to describe the dynamic characteristics of the port of the PMSG, and the analysis of active and reactive response characteristics of PMSG lays the foundation for model simplification. Based on the unit model, a direct-drive wind farm aggregation equivalence method based on the excitation–response relationship is proposed. The equivalent model obtained by this method is suitable for the small disturbance stability analysis of direct-drive wind farms grid connected system, with good accuracy. The simulation verified the effectiveness of the aggregation model. [ABSTRACT FROM AUTHOR]

Background: Three-dimensional (3D) printing is becoming increasingly popular around the world not only in engineering but also in the medical industry. This trend is visible, especially in aortic modeling for both training and treatment purposes. As a result of advancements in 3D technology, patients can be offered personalized treatment of aortic lesions via physician-modified stent grafts (PMSG), which can be tailored to the specific vascular conditions of the patient. The objective of this systematic review was to investigate the utility of 3D printing in PMSG in aortic lesion repair by examining procedure time and complications. Methods: The systematic review has been performed using the PRISMA 2020 Checklist and PRISMA 2020 flow diagram and following the Cochrane Handbook. The systematic review has been registered in the International Prospective Register of Systematic Reviews: CRD42024526950. Results: Five studies with a total number of 172 patients were included in the final review. The mean operation time was 249.95± 70.03 min, and the mean modification time was 65.38 ± 10.59 min. The analysis of the results indicated I2 of 99% and 100% indicating high heterogeneity among studies. The bias assessment indicated the moderate quality of the included research. Conclusions: The noticeable variance in the reviewed studies' results marks the need for larger randomized trials as clinical results of 3D printing in PMSG have great potential for patients with aortic lesions in both elective and urgent procedures. [ABSTRACT FROM AUTHOR]

In order to explore the optimal estrus synchronization plan for Cervus nippon, 163 healthy, normal estrus cycle, and well reproducing female deer were selected from Shuangyang Deer Industry Breeding Co., Ltd. in Jilin Province and randomly divided into three groups: Group A was treated with domestic vaginal progesterone suppositories (CIDR), Group B was treated with imported CIDR, and Group C was treated with secondary PG supplemented with pregnant horse serum gonadotropin (PMSG). Another 100 female deer were randomly divided into four groups, and the selected optimal plan was combined with different doses of PMSG treatment (100 IU in Group Ⅰ, 300 IU in Group Ⅱ, 500 IU in Group Ⅲ, and 700 IU in Group Ⅳ), to explore the effects of different estrus treatment plans on the estrus effect, estrus time distribution, conception rate, and twin lambing rate of C. nippon, as well as the effects of different PMSG doses on the estrus conception of female deer. The results showed that there was no significant difference in the synchronous estrus rate between Group A and Group B, but the synchronous estrus rate in Group A and Group B was 23. 5% and 33. 3% higher than those in Group C, respectively (p<0. 01), and the thrombus shedding rate in Group A was 8. 8% higher than that in Group B (p<0. 05). The three treatment schemes had a significant impact on the distribution of estrus time (p<0. 01). Compared with Groups A and C, the fertility rate and farrowing rate in Group B wer higher than those in Groups A and C, respectively 6. 5% and 9. 8% (p> 0. 05), the twin rate is higher than 13. 4% and 17. 6% (p>0. 05). Adopting imported CIDR combined with different doses of PMSG for synchronous estrus treatment of C. nippon revealed that the estrus rate in the Groups Ⅱ, Ⅲ, and Ⅳ was 36. 0%, 40. 0%, and 48. 0% higher than that in Group Ⅰ (p<0. 05), showing an increasing trend with the increase of PMSG dose. There was no significant difference between the other Groups (p>0. 05), but the estrus time was concentrated between 24-48 hours. The conception rates of Groups Ⅰ, Ⅱ, Ⅲ and Ⅳ were 46. 2%, 61. 9%, 59. 1%, and 50. 0%, respectively, showing a trend of first increasing and then decreasing (p>0. 05). In summary, the estrus plan of vaginal embedding is significantly better than the secondary PG method, and imported CIDR is better than domestic CIDR. The estrus rate and conception rate of imported CIDR+PMSG female deer increase significantly with the increase of PMSG dose, but the estrus time is not affected by PMSG dose. The appropriate dose of PMSG is 300 IU. [ABSTRACT FROM AUTHOR]

This paper presents the control strategies and performance analysis of doubly fed induction generator (DFIG) for grid-connected wind energy conversion system (WECS). The wind power produces environmentally sustainable electricity and helps to meet national energy demand as the amounts of non-renewable resources are declining. The development of the WECS can be seen with development in power electronics technology. Currently, two types of major generator used in WECS these are DFIG and the permanent magnet synchronous generator (PMSG). Both variable oprational speed are used in wind turbine. Because its high performance, reliability, controllability and high-power and voltage capabilities, multilevel converters have become a popular option for multi-MW WECSs. This paper focuses on the application of back-to-back modular multilevel converters in a DFIG and PMSG-based WECS. A comparative performance analysis of the two systems based on power quality, active, reactive power, and modular multilevel converter dynamics is presented. The comparison is based on simulation results created in MATLAB/Simulink software. [ABSTRACT FROM AUTHOR]

The goal of this paper is to optimize the rotor design parameters of 4000 rpm permanent magnet synchronous generator. The factors namely embrace, offset, outer diameter, and magnet thickness are selected as the design parameters those will be optimized in order to hold the magnetic flux density (MFD) distribution and the flux density on stator teeth and stator yoke within a desirable range while maximizing efficiency. The numerical simulations are carried out in the Maxwell environment for this purpose. The mathematical relationships between the responses and the factors are then derived using regression modeling over the simulation data. Following the modeling phase, the moth flame optimization is applied to these regression models to optimize the rotor design parameters. The motivation is determining mathematical relation between the important design parameters of the high speed generator and the measured responses, when standard M530-50A lamination material is used and then to demonstrate the utility of MFO to the readers on this design problem. The optimum factor levels for embrace, offset, outer diameter, and magnet thickness are calculated as 0.68, 30, 161.56, and 8.92 respectively. Additionally, confirmations are done by using Maxwell and the efficiency is calculated as 94.85%, and magnetic distributions are calculated as 1.64, 0.26, and 0.93 Tesla for stator teeth flux density, stator yoke flux density, and MFD; respectively. The results show that the efficiency is maximized and the magnetic distributions are kept within an appropriate range. [ABSTRACT FROM AUTHOR]

In modern power systems, the increasing penetration of renewable energy resources has reduced frequency stability. Consequently, wind turbines (WTs) are expected to participate in frequency regulation. By integrating the electrostatic energy stored in the DC capacitor with the kinetic energy stored in the rotating mass of the WT, an advanced control method is implemented to facilitate frequency regulation. However, previous studies have mainly concentrated on frequency control using WTs but ignored the rotor speed recovery of WT. Therefore, this work proposes a novel control strategy that separates the operating mode of a WT into two distinct states: the frequency support and the recovery of rotation speed stages. The proposed method improves the recovery process for rotor speeds after a WT participates in frequency support, returning the WT quickly to its normal operation to reduce wind energy loss. Furthermore, a new adaptive DC virtual inertia (DVIC) coefficient that utilizes real-time DC voltage to adjust the DVIC’s output smoothly is proposed. The proposed strategy is compared with other mature control strategies and implemented in PSCAD/EMTDC to verify their effectiveness and robustness. The simulation results demonstrate that the proposed method outperforms other mature methods because it reduces wind energy loss by at least 15 % when WTs participate in the frequency support process.

The potential of renewable energy in Indonesia is very large with a total of 3,643.0 GW. One of them is wind energy, the huge potential of wind energy which is 154.9 GW is very wasted if it is not optimized as well as possible. The biggest obstacle to utilizing wind potential is low wind speed in some areas in Indonesia. So an effective generation system is needed to produce efficient output. A permanent Magnet Synchronous Generator (PMSG) is very suitable for use in areas of potential low-speed winds because low rotation can produce good efficiency. The output value of the Permanent Magnet Synchronous Generator (PMSG) is currently still low and can still be improved, for this research will analyze the broad influence of the cross-section of the winding wire on the stator on the efficiency of the 18 slots 16 poles Permanent Magnet Generator with rotational speed based on wind speed in Indonesia. Variations were carried out on a cross-sectional area of 0.6 mm2-3.6 mm2 winding wire and rotating speeds of 500 rpm, 750 rpm, and 1000 rpm. By using MagNet Infolytica 7.5 software based on Finite Element Method (FEM) to obtain output values in the form of voltage, current, and torque. For efficiency values, data is reprocessed using Microsoft Excel. The results of this study show that the value of efficiency increases. The best efficiency produced when the rotating speed is 500 rpm is 97.04% at a cross-sectional area of 2.6 mm2 winding wire, for a rotating speed of 750 rpm the efficiency reaches 97.24% at a cross-sectional area of 2.4 mm2 winding wire and at a rotating speed of 1000 rpm the resulting efficiency is 97.16% at a cross-sectional area of 2.4 mm2 winding wire.

This paper presents a study of a robust control strategy based on the Attractive Ellipsoid Method (AEM) to achieve trajectory tracking for a Permanent Magnet Synchronous Generator (PMSG). For the PMSG system, trajectory tracking control is necessary such that the maximum power point tracking can be carried out, which depends on controlling time-varying references (the generator angular speed), mainly when the generator motion is originated from a variable and intermittent energy source such as the wind. The proposed controller is based on the selection of the best gain matrix by numerically employing the AEM with the bilinear matrix inequality technique application. The controller guarantees that the trajectory tracking error reaches an ellipsoid of small enough size, which is determined in an optimized way, such that the practical stability for the tracking error is ensured. The effectiveness of the proposed controller is verified via simulations for a PMSG coupled with a three-phase rectifier, where the variables to be controlled reach the desired time-varying references, additionally a comparison is made against a classical Proportional Integral (PI) control scheme and a state feedback LQR controller. [ABSTRACT FROM AUTHOR]

In recent era, the reduction of greenhouse gas emission and fuel consumption is accompanied by adopting photovoltaic (PV) and wind turbine-based hybrid renewable energy sources (HRES). In nature, an intermittent characteristic of the wind speed and solar irradiation makes these sources unpredictable, and hence, energy produced by wind and PV system generates uncertain conditions in operation of microgrid. In such cases, the security and reliability of microgrid are enhanced by integration of energy storage system (ESS). This work deals with an energy management in a hybrid system incorporating PV source and permanent magnet synchronous generator (PMSG)-based wind energy system. The PV output is enhanced with a help of switched trans-quasi-Z-source (TQZS) boost converter in which cuckoo search-assisted radial basis function neural network (RBFNN) approach is used as maximum power point tracking (MPPT) technique for tracking maximum photovoltaic power. The proposed approach results in high-power tracking efficiency with reduced power loss and settling time. A battery is incorporated to address an intermittent nature of RES. Artificial neural networks (ANN), which are capable of self-learning battery dynamics, keep track of the state-of-charge (SOC) of the battery. The system thus framed is implemented using MATLAB software, and promising results are generated in terms of power management with improved efficiency of 92%, gain ratio of 1:10 and total harmonic distortion (THD) value of 2.33%, respectively. [ABSTRACT FROM AUTHOR]

This research explores the use of contemporary controllers, especially fuzzy logic, to improve how the wind turbine systems react on external disturbances such as blades distortion. The study concentrates on these controllers' workability in relation to the speed control for turbines integrated into the network-based management and production system, using a wind turbine with permanent magnet synchronous generator (PMSG). Pitch of the blade control strategies are being compared using a comparative analysis between traditional ones and the one with multiple variables performed in terms of fuzzy logic controller. The focus here is on the assessment of how such controllers affect the transient speed signals, with a brief mention regarding the average value derived from simulations. The results show that the fuzzy logic-PI control significantly outperforms the standard controllers in terms of wind turbine speeding performance. [ABSTRACT FROM AUTHOR]

This paper deals with the design of five-phase permanent magnet synchronous machines (PMSMs) exploiting the third harmonic for torque generation. Through the optimization of the stator size and rotor structure, the objective functions related to mass and electric losses are minimized for a targeted electromagnetic power (10 kW and 400 rpm) and a given volume. The study takes into account saturation, thermal, electrical and mechanical constraints. On that note, a 1D analytical magnetic model, considering the existence and use of the third harmonic, is presented. The design optimization then shows how the use of harmonic 3 can improve the machine's performance. It will be shown that, for a given electromagnetic torque, taking the third harmonic into account in the sizing process leads to a mass reduction that can reach 20% and electrical losses that can go up to 21%. A finite element analysis model of the five-phase PMSM is then established in order to verify the results of the optimization and validate them. [ABSTRACT FROM AUTHOR]

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Energy storage systems (ESS) and permanent magnet synchronous generators (PMSG) are speculated to be able to exhibit frequency regulation capabilities by adding differential and proportional control loops with different control objectives. The available PMSG kinetic energy and charging/discharging capacities of the ESS were restricted. To improve the inertia response and frequency control capability, we propose a short-term frequency support strategy for the ESS and PMSG. To this end, the weights were embedded in the control loops to adjust the participation of the differential and proportional controls based on the system frequency excursion. The effectiveness of the proposed control strategy was verified using PSCAD/EMTDC. The simulations revealed that the proposed strategy could improve the maximum rate of change of the frequency nadir and maximum frequency excursion. Therefore, it provides a promising solution of ancillary services for frequency regulation of PMSG and ESS. [ABSTRACT FROM AUTHOR]

Low-voltage ride-through (LVRT) capability is crucial for wind power plants that are grid-connected. A grid code requires wind farms to remain on-grid and inject a specific reactive current when a grid fault occurs. The requirements are satisfied by a cooperative control scheme of a battery energy storage system (BESS) and grid-side converter (GSC) for improving the LVRT capacity of wind turbine generators using permanent magnet synchronous generators. The proposed approach uses the BESS to absorb a power difference that appears in the back-to-back converters during the LVRT operation. Hence, the DC-link voltage is regulated by the BESS. In addition, the GSC control allows reactive current to be injected into the grid according to the grid code requirements. Finally, the wind turbine generators, which use the proposed approach, are built in MATLAB/Simulink. The theoretical analysis of the proposed method is validated by simulation.

This work presents the study of a wind energy conversion system based on permanent magnet synchronous generator controlled by an advanced frequency techniques applied to two levels of control system: turbine speed control which allows to extract the maximum wind power based on the control of the PMSG electromagnetic torque and Vdc (DC-link voltage) control based on vector control to ensure a constant tension under the variations in the wind speed. The robust H∞ control efficacy is validated in comparison with the MPPT controller based on perturb and observe algorithm and conventional regulator PID. The computer simulation results obtained by a realized graphical user interface (GUI) using robust H∞ controller with robustness test (variations in electrical and mechanical parameters) show considerable improvements in dynamics performances, robustness stability and good adaptation of the robust H∞ parameters under uncertain constraints. [ABSTRACT FROM AUTHOR]

In this paper, a sliding mode controller is implemented to a permanent synchronous generator direct driven wind energy conversion system. The goal of this proposed work is to control the stator directly and quadrature axis currents to minimize the chattering phenomenon. To achieve this goal, we use two numerical techniques which are PSO (particle swarm optimization) and GWO (grey wolf optimization) algorithms to obtain gains parameters of the controller. The analysis of the recommended approach robustness and responsiveness of the system has been carried out under the real wind speed of the Adrar region (south of Algeria) and simulation results are tested under MATLAB/Simulink tool. The main result shows the effectiveness and the better performance of the PSO compared to the GWO. [ABSTRACT FROM AUTHOR]

Comparative studies of intravaginal sponges containing three different doses of progesterone on estrous synchronization; fertility, fecundity and prolificacy of synchronized does by natural mating were conducted during the breeding season at Central Sheep Breeding Farm, Hisar. A total of 60 Beetal does selected randomly and divided into group I, II and III with 20 does in each, and subsequently intravaginal sponges containing 50, 100 and 150 mg P4 were inserted respectively for 14 days and an i/m injection of PMSG (@200IU/doe) was injected just after sponge removal in each doe. Effective number of animals remained 55 as 5 does dropped their sponges. Forty eight to sixty hrs after sponge removal, 14, 16 and 15 does from group I, group II and group III respectively were synchronized to estrus and subsequently hand mated individually with bucks of proven fertility. The fertility, fecundity and prolificacy per cent after synchronization of oestrus in group I, group II and group III were 78.57, 87.50 and 86.66;128.57, 156.25 and 166.66; 163.63, 178.57 and 192.30 respectively. Eighteen animals (6 does from each group) selected randomly out of 60 animals for progesterone estimation. Blood samples were collected immediately before insertion of intravaginal sponges (day 0) and then subsequently on day 7, 14 after sponge insertion and 48 and 72 hrs after sponge removal. Progesterone concentration was above basal level in most of animals on day 0 in all the groups. Increase in plasma progesterone concentration (with in group) was recorded on day 7 and decreased on day 14 & 48 hrs after sponge removal. These changes were significant in group II & III while non-significant in group I. Progesterone concentration decreased non-significantly 72 hours after sponge removal in all the three groups. Significant difference in plasma P4 concentration was reported in between group I and group II & III on day 7 & 14. [ABSTRACT FROM AUTHOR]

In view of the importance of the trend and the need for energy transition throughout the world, and in Algeria in particular, the production of electrical energy based on renewable energy, wind energy depends essentially on wind speed, and as this is of a random nature, it therefore constitutes the problem of control to instantly extract the maximum power produced. The aim is to apply adaptive backstepping control on the turbine side and to evaluate the performance of the permanent magnet synchronous generator operating at variable speed. As well as a genetic algorithm-adjusted Integral Proportional Controller (IPC) to overcome the drawbacks of parameter sensitivity, in order to ensure efficient power management on the grid side to which the wind turbine system is connected, makes a significant contribution to improving performance, stability, reliability and research in the field of grid-connected wind power systems. The efficiency of the structure under consideration is validated using MatLab Simulink. [ABSTRACT FROM AUTHOR]

Ensuring the quality and stability of the electrical grid is of utmost importance during the phase of electrical energy production. As wind energy plays an increasingly significant role in a country's energy composition, maintaining stability and optimal quality has emerged as a prerequisite for the generated electricity. This article aims to devise a dynamic nonlinear algorithm that can be implemented in the wind energy conversion system (WECS) featuring a direct-drive permanent magnet synchronous generator (PMSG). Notably, the adaptive backstepping control relies on the nonlinear model of the controlled system. It harnesses the principles of the Lyapunov stability theory to regulate various parameters and uphold the overall system's stability. Employing simulation analysis through the Matlab–Simulink environment, the proposed control strategy is evaluated using a 1.5 MW wind turbine. The results showcase the robust capability of the suggested control algorithm: it effectively maintains the DC bus voltage and produces high-quality electrical energy with a total harmonic distortion (THD) below 0.38%. Moreover, the algorithm demonstrates added resilience. The practical viability of the adaptive control algorithm is validated through an experimental study on the dSPACE DS1104 prototyping platform. This study underscores the algorithm's proficiency in achieving all control objectives under diverse wind scenarios. [ABSTRACT FROM AUTHOR]

The aim of the present study was to induce estrus synchronization in ewes after administration of progestagen for 12 days and various subsequent treatments (with FFA, GnRH analogue or no treatment) after cessation of its action. The experiment was conducted in August, 2022, with 27 sheep from the Synthetic Bulgarian Dairy Population. All ewes were treated with vaginal sponges, containing 30 mg FGA (duration of stay - 12 days) and the formation of experimental groups was according to follow-up treatment after sponge removal: I group - experimental animals were treated with 400 UI of PMSG at the time of removal of sponges. II group - the sheep were treated with 1 ml of GnRH analogue, containing busorelin acetate 0.004 mg/ml, 24 hours after sponge removal. III group – no treatment after sponge removal. The next parameters were studied: estrus synchronization rate, fertility and fecundity were studied. The estrus synchronization rate was the highest for I group - 100% and the lowest for II group - 66.67%. Fertility was highest in III group - 87.50%, and lowest in II group - 50.0%. Fecundity was highest in I group - 171.43%, while in other groups it was 133.33% and 128.57%, respectively, for II group and III group. Based on the obtained results, it could be concluded that GnRH analogue treatment, given solely 24 hours after sponge removal, didn’t have the synchronization effect as the classical follow- up treatment with PMSG. No follow-up treatment after sponge removal was better alternative that GnRH treatment. [ABSTRACT FROM AUTHOR]

At present, the direct drive permanent magnet synchronous generator (DD-PMSG) grid connected system based on virtual synchronous generator (VSG) control will experience power oscillation at sub synchronous frequencies. The mechanism and characteristics of this new type of sub-synchronous interaction (SSI) are not yet clear, and the system cannot recover to steady state solely based on the characteristics of VSG itself. Especially when connected to a weak current network, oscillations are more pronounced, affecting the stability of the system. In severe cases, the system may trigger shutdown protection and be disconnected from the network. Existing research has only analyzed the oscillation mechanism under this phenomenon and has not proposed corresponding control strategies. This article proposes a VSM control strategy based on the VSG control algorithm, which balances the dq axis component of voltage and current, and improves the voltage and current loop of VSG control to reduce the impact of sub-synchronous oscillation (SSO) on the power grid. In MATLAB/Simulink, a simulation model of the proposed control strategy was built to verify its correctness and effectiveness. [ABSTRACT FROM AUTHOR]

In this paper, Fast space vector pulse width modulation (SVPWM) and a switching structure based on sliding mode control (SMC) and active disturbance rejection control (ADRC) are proposed to improve the dynamic performance and restrain the disturbance of the offshore permanent magnet synchronous generator (PMSG) wind power system. According to the known or unknown system states and the types of disturbance, the control systems switch to the different controller to overcome the unknown states and disturbances effects. Compared to the traditional SVPWM algorithm, the fast SVPWM algorithm has more strong function of pulse modulation and harmonic wave restraints, and shortens the data processing time. The simulation results show that the SMC and ADRC control based on the switching structure restrain the different types of disturbances in complicated offshore environment, and improve the response speed and energy conversion rate of the PMSG wind power system. [ABSTRACT FROM AUTHOR]

The goal of this paper is to optimize the rotor design parameters of 4000 rpm permanent magnet synchronous generator. The factors namely embrace, offset, outer diameter, and magnet thickness are selected as the design parameters those will be optimized in order to hold the magnetic flux density (MFD) distribution and the flux density on stator teeth and stator yoke within a desirable range while maximizing efficiency. The numerical simulations are carried out in the Maxwell environment for this purpose. The mathematical relationships between the responses and the factors are then derived using regression modeling over the simulation data. Following the modeling phase, the moth flame optimization is applied to these regression models to optimize the rotor design parameters. The motivation is determining mathematical relation between the important design parameters of the high speed generator and the measured responses, when standard M530-50A lamination material is used and then to demonstrate the utility of MFO to the readers on this design problem. The optimum factor levels for embrace, offset, outer diameter, and magnet thickness are calculated as 0.68, 30, 161.56, and 8.92 respectively. Additionally, confirmations are done by using Maxwell and the efficiency is calculated as 94.85%, and magnetic distributions are calculated as 1.64, 0.26, and 0.93 Tesla for stator teeth flux density, stator yoke flux density, and MFD; respectively. The results show that the efficiency is maximized and the magnetic distributions are kept within an appropriate range.

Wind energy is one of the alternative energies that can overcome global warming caused by fossil energy. Permanent Magnet Synchronous Generator (PMSG) has a higher efficiency compared to other types of generators. The previous permanent magnet synchronous generator model was only able to produce efficiency at a rotational speed of 500 rpm of 67.30% and at a rotational speed of 1500 rpm of 80.9%, so further research is needed to get a higher efficiency value. This study aims to analyze the effect of magnetic thickness and rotational speed on PMSG characteristics and obtain a higher efficiency value. Using variations in magnetic thickness of 7.5mm, 9 mm, and 10 mm and variations in rotational speed of 500 rpm, 1000 rpm, and 1500 rpm using software based on Finite Element Methode, this study obtained the results of the largest current, voltage, input power, and output power at a magnetic thickness of 10mm with a rotational speed of 1500 rpm of 20.40 A, 204.06 V, 4979.60 W, and 4266.21 W, with the greatest efficiency being in the magnetic thickness of 9mm and 10 rpm of 89.20%

Wind energy in Indonesia has great potential so it needs to be utilized to produce electrical energy in the context of energy transition. However, its medium-low speed is a challenge to maximize its potential. A suitable generator for use is a Permanent Magnet Synchronous Generator (PMSG). However, the PMSG used today has low efficiency and characteristics. This study uses the best parameters from previous studies and adds updates to the magnetic thickness and number of windings to produce high-characteristic PMSG. Researchers design and test through simulation with the help of Magnet Infolytica software with Finite Element Method (FEM) method. The simulated values are processed using Microsoft Excel to produce input power, output power, and efficiency values. The variations in magnetic thickness used are 3 mm, 6 mm, and 9 mm. The variations in the number of windings used are 20, 30, and 40 windings. The results of the research simulation showed that the highest characteristics produced were PMSG thickness of 9 mm and winding 40 with a current of 26,59 A, voltage of 265,88 V, torque of -73,85 Nm, input power of 7.744,71 W and output power of 7.266,01 W. While the greatest efficiency is PMSG thickness of 9 mm and winding 30 with a current of 24,36 A, voltage of 243,58 V, torque of -61,52 Nm, Input power 6.441,46, output power 6.101,13 and efficiency 94,70%.

Background: Three-dimensional (3D) printing is becoming increasingly popular around the world not only in engineering but also in the medical industry. This trend is visible, especially in aortic modeling for both training and treatment purposes. As a result of advancements in 3D technology, patients can be offered personalized treatment of aortic lesions via physician-modified stent grafts (PMSG), which can be tailored to the specific vascular conditions of the patient. The objective of this systematic review was to investigate the utility of 3D printing in PMSG in aortic lesion repair by examining procedure time and complications. Methods: The systematic review has been performed using the PRISMA 2020 Checklist and PRISMA 2020 flow diagram and following the Cochrane Handbook. The systematic review has been registered in the International Prospective Register of Systematic Reviews: CRD42024526950. Results: Five studies with a total number of 172 patients were included in the final review. The mean operation time was 249.95± 70.03 min, and the mean modification time was 65.38 ± 10.59 min. The analysis of the results indicated I2 of 99% and 100% indicating high heterogeneity among studies. The bias assessment indicated the moderate quality of the included research. Conclusions: The noticeable variance in the reviewed studies’ results marks the need for larger randomized trials as clinical results of 3D printing in PMSG have great potential for patients with aortic lesions in both elective and urgent procedures.

The purpose of frequency response of PMSG wind turbine is to provide additional energy support to the power system’s frequency regulation demand through its rotor kinetic energy. However, the inherent control loop represented by the PMSG speed controller, and its inherent control purpose is to maintain a stable operation of the rotor speed, thus the difference between these two control blocks will lead to a conflict situation between frequency response performance and operation safety of the wind turbine. Therefore, a novel fuzzy-based coordinated control and parameter correction strategy for speed controller of PMSG wind turbine in frequency response is proposed in this paper. First, to clarify the function role of key parameters of the wind turbine in frequency response process, a mapping equivalence model consisting of wind turbine’s frequency response parameters and operation states is proposed by establishing the energy correspondence relationship between PMSG rotor kinetic energy, de-loading reserve by pitch angle control and power demand of frequency response. Then, the frequency response performances of the speed controller’s parameters are tested under various wind speeds. Moreover, based on the fuzzy logic algorithm, a dynamic operation strategy for the wind turbine’s speed controller is proposed to improve the frequency response performance, which alleviates its conflict against the PMSG frequency response control block. Finally, a simulation model is built to verify the proposed strategy under various wind scenarios. The test results demonstrate that the frequency response performance and the speed controller’s inherent control function of the PMSG-wind turbine can be effectively coordinated by deploying the proposed strategy, and the frequency support capability of the power system is effectively improved.