Search

ABSTRACT In this experimental study, a new technique is designed and presented for controlling the rotor side converter of an induction generator (IG) for multi‐rotor wind turbine (MRWT) systems. The direct power command (DPC) strategy is used to regulate the reactive and active power (Qs and Ps). DPC is characterized by several drawbacks, the most prominent of which are low durability, low current/power quality, and the use of power estimation. Therefore, a new PDPI (proportional‐derivative proportional‐integral) regulator is used as a suitable solution to overcome these shortcomings while maintaining simplicity, achieving a rapid dynamic response, and obtaining gains that characterize the DPC. The suggested DPC for controlling the IG inverter of an MRWT system uses two PDPI regulators and pulse width modulation (PWM) to create and generate the pulses necessary to run and regulate the IG inverter. First, the DPC‐PDPI‐PWM is verified in a MATLAB using different tests, and the characteristics of the DPC‐PDPI‐PWM is compared to that of DPC under different working conditions for a 1500 kW IG. Second, the validity of the simulated results is verified using the Hardware‐in‐the loop (HIL) test for the DPC‐PDPI‐PWM, and dSPACE 1104 is used for this purpose. The results demonstrate the effectiveness of the DPC‐PDPI‐PWM approach over DPC, as the harmonic distortion of the stream is minimized by 36.66%, 22.68%, and 33.33% in the three proposed tests. Also, the overshoot value of Ps was reduced compared to DPC by ratios estimated at 70.96%, 71.42%, and 70.31% in all tests. DPC‐PDPI‐PWM also reduces the steady‐state error of Qs compared to DPC by 68.33%, 58.82%, 67.90% in all tests performed. The experimental results confirm the numerical results, suggesting that the DPC‐PDPI‐PWM is a suitable solution in the field of command in the future.

Permanent magnet synchronous machines (PMSMs) contain a simple structure, high efficiency, and simple control. However, their cost has increased significantly due to the increase in the price of permanent magnets. Wound rotor synchronous machines (WRSMs) can be used as an alternative to PMSMs. In WRSMs, there is no need for permanent magnets as the rotors of these machines are electromagnets. However, there is the sparking issue which consequently requires regular maintenance of slip rings and carbon brushes. The research focus in recent times is to eliminate the brushes and slip rings in the conventional WRSMs. This manuscript presents a novel brushless wound rotor synchronous machine (BL-WRSM) utilizing an inherent subharmonic component (SHC). The proposed design achieves a brushless function by utilizing the inherent SHC of the stator magnetomotive force (MMF) inherently available in the air gap. As compared to the existing distributed winding BL-WRSM, the proposed BL-WRSM does not involve any extra circuitry at the stator side, additional inverter, or special stator winding arrangements. Utilizing SHC provides benefits such as reduced torque ripple and symmetrical flux distribution as compared to existing brushless machines. There are two distinct windings present on the rotor in the suggested BL-WRSM. These are field winding (FW) and harmonic winding (HW). A rectifier connects these windings in parallel with one another. The SHC of stator MMF generates an AC voltage in HW. This AC voltage is converted to DC by a rectifier, which powers the rotor FW. Validation of brushless operation of the suggested 8-pole, 12-slot machine is conducted through a 2-dimensional finite element analysis with the help of JMAG software. The suggested topology results in desired torque at rated speed with low torque ripples.

In order to avoid large vibration response and transcritical motion instability of ultra-high speed centrifugal impeller rotor system caused by unbalanced excitation, the unbalanced excitation response of ultra-high speed centrifugal impeller rotor system was analyzed by using Ansys rotor dynamics response analysis module and comprehensively considering the stiffness and damping of sliding bearing, the dynamic response of ultra-high speed centrifugal impeller rotor system under different unbalanced excitation was obtained.At the same time, DEWESoft vibration test system was used to track and record the rotating frequency vibration value of ultra-high speed centrifugal impeller rotor system, and compared with the unbalanced response analysis results, it was concluded that the dynamic balance accuracy level of the ultra-high speed centrifugal impeller rotor system should be better than G1 level. The unbalanced excitation response analysis and control method has been well verified by tests, which has important engineering application significance.

Abstract In this paper, a high speed slotted solid-rotor induction motor (SSRIM) with rated power of 15 kW and rated speed of 120krpm is studied, and its electromagnetic performance and rotor mechanical structure are optimized. First, according to the empirical formula of motor design, the volume size of the motor is determined. Then, by constructing a two-dimensional finite element model, the slot matching scheme and coil pitch are optimized, and the influence of different slot matching scheme and coil pitch on the output torque and harmonics of the motor is compared. Then, the influence of rotor slot size on electromagnetic and mechanical properties of the motor is described in detail. Finally, a finite element model is constructed to verify the mechanical strength of the rotor, and the influence of temperature on the deformation and stress of the rotor is explored. Through the analysis, it is found that the slot matching scheme has a great influence on the torque ripple of the motor, and the torque ripple can be reduced by selecting the slot matching scheme reasonably. Secondly, the size of the rotor slot has a great impact on the electromagnetic and mechanical properties of the motor, and it is necessary to comprehensively consider and jointly optimize its size.

In this study, we present an improved linear quadratic closed-loop rotor vibration controller that uses a steady-state Kalman filter and an augmented integral controller to improve the traditional T-matrix-based rotor vibration controller. The proposed linearized vibration controller features closed-loop stability more rigorously than the conventional algebraic T-matrix-based controller. A relative multi-loop stability margin analysis was performed and examined using a nonlinear aeroservoelastic rotor software-in-the-loop simulation. The rotor aeroservoelastic simulation was performed using the multi-body dynamic analysis software DYMORE, equipped with a new improved inflow model employing multiple trailer time-marching free-vortex wakes. A linear time periodic representation of the rotor was identified from the exponentially modulated periodic response obtained using a recursive Fourier series filter. We found that the proposed linear controller showed improved numerical phase-margin prediction accuracy compared with the T-matrix-based method. Finally, the trade-off between the rotor vibratory load reduction performance and closed-loop stability was evaluated and discussed. We found that the proposed controller asymptotically reduced the N/rev vibratory loads that were included in the Kalman filter, and the amount of load reduction was similar to that predicted from the LTP rotor harmonic system.

Abstract The direct power control (DPC) algorithm is one of the most popular linear techniques used to implement notable controllers, known for their simplicity and fast dynamic response. However, this approach has drawbacks that cause a decrease in the current quality and disturbances in the network. Therefore, this experimental work presents a simple and efficient solution that uses a proportional-integral regulator based on a genetic algorithm to regulate the power quality. The designed approach uses a pulse width modulation to produce control pulses for the operation of the rotor inverter of a doubly-fed induction generator-based multi-rotor wind system. This approach is first verified in MATLAB using a 1500 kW generator operating under different working conditions. Furthermore, the processor-in-the-loop (PIL) test using dSPACE 1104 is used to verify the efficacy and ability of the designed approach in enhancing the effectiveness of the power system under study. The results obtained in all tests demonstrate that compared to DPC, the designed approach reduces active power ripples with estimated percentages of 71.42%, 66.67%, and 70%, and the reactive power overshoot value is reduced with estimated percentages of 92.85%, 56.48%, and 79.21%. In addition, the experimental results (using the PIL test) confirm the ability of the designed control algorithm to enhance the energy and current quality, which makes this designed technique a suitable solution in the field of control.

Abstract In wind energy generation systems, ensuring high energy quality is critical but is often compromised due to the limited performance and durability of conventional regulators. To address this, this work presents a novel controller for managing the machine-side inverter of a single-rotor large wind turbine system using an induction machine-type generator. The proposed controller is designed using proportional, integral, and derivative error-based mechanisms, which fundamentally differ from traditional proportional-integral (PI) regulators. Key features of the proposed regulator include its simplicity, cost-effectiveness, ease of implementation, reduced number of gains, and rapid dynamic response. This regulator enhances the direct power control (DPC) approach, as it integrates two tailored controllers alongside a pulse width modulation strategy to manage the machine inverter. The DPC strategy incorporating the proposed controller was implemented and tested using MATLAB, with various simulations to evaluate its performance and effectiveness. The proposed regulator demonstrated a significant improvement over the PI regulator, with reductions in active power ripples of 69%, 61.70%, and 59.14% across different tests. Additionally, the steady-state error of reactive power was reduced by 54.84%, 85.23%, and 62.68%, and the total harmonic distortion of current decreased by 48.12%, 50.55%, and 56.05%. These results underscore the high efficiency, robustness, and effectiveness of the proposed controller in improving system performance compared to conventional PI regulators. The controller’s outstanding performance makes it a promising solution for broader industrial applications.

This paper deals with the development, modeling, identification, and robust control of a twin-rotor MIMO system (TRMS). The TRMS is a two rotational degree-of-freedom unstable structure with significant channel-coupling, nonlinear characteristics, and external disturbances, which resembles a real helicopter’s characteristics and can be used as an aerodynamic testing setup. The coupled nonlinear state-space representation of the developed TRMS is obtained, and model parameters are identified. The identified model is validated using different experimental test scenarios. To estimate the lumped uncertainty including cross-coupling effects and external disturbances, a novel finite-time sliding mode disturbance observer is proposed. Based on the presented disturbance observer, a finite-time sliding mode controller is designed for the coupled identified TRMS. Performance evaluation of the presented observer-based controller is demonstrated through a series of experiments and simulations. The robustness of the proposed scheme is shown. Moreover, an average improvement of approximately 20% in system performance, as measured by the reduction in the Integrated Squared Error (ISE), is observed compared to the PID controller.