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In this paper, an extendable fuzzy robust speed controller suitable for induction motor drive systems was proposed. Firstly, the two-degrees-of-freedom (2DOF) robust control technology with feedforward control and disturbance elimination method was adopted. Upon parameter variation and load disturbance, the motor drive system could utilize a robust controller to generate compensation signals and reduce the impact on the controlling performance of the motor drive system. The magnitude of the compensation signal was adjusted via the weighting factor. However, should a fixed weighting factor be adopted, system instability might be generated easily when time delay and saturation of control force occur. Based on the above, the smart method of extendable fuzzy theory (EFT) was adopted in this paper to adjust adequate weighting factors, where the controlling performance of the induction motor drive system could be improved accordingly. Lastly, the simulation software Matlab/Simulink (R2023b version) was applied to simulate the utilization of the controlling method proposed for the induction motor drive system. The simulation results proved that the extendable fuzzy robust speed controller proposed provided better speed tracking and load regulation-controlling performance than the conventional robust controller. [ABSTRACT FROM AUTHOR]

This paper presents the design of a robust speed controller for brushless DC motors (BLDCMs) under field-oriented control (FOC). The proposed robust controller integrates extension theory (ET) and sliding mode theory (SMT) to achieve robustness. First, the speed difference between the speed command and the actual speed of the BLDCM, along with the rate of change of the speed difference, are divided into 20 interval categories. Then, the feedback speed difference and the rate of change of the speed difference are calculated for their extension correlation with each of the 20 interval categories. The interval category with the highest correlation is used to determine the appropriate control gain for the sliding mode speed controller. This gain adjustment tunes the parameters of the sliding surface in the SMT, thereby suppressing the overshoot of the motor's speed. Because a sliding surface reaching law of the sliding mode controller (SMC) adopts the exponential approach law (EAL), the system's speed response can quickly follow the speed command in any state and exhibit an excellent load regulation response. The simplicity of this robust control method, which requires minimal training data, facilitates its easy implementation. Finally, the speed control of the BLDCM is simulated using Matlab/Simulink software (2023b version), and the results are compared with those of the SMC using the constant-speed approach law (CSAL). The simulation and experimental results demonstrate that the proposed robust controller exhibits superior speed command tracking and load regulation responses compared to the traditional SMC. [ABSTRACT FROM AUTHOR]

In this paper, a method based on an improved intelligent bat algorithm (IIBA) in cooperation with a voltage and current sensor was applied in maximum power point tracking (MPPT) for a photovoltaic module array (PVMA), where the power generation performance of a PVMA was enhanced. Due to the partial shading of the PVMA from climate changes or the surrounding environment, multiple peak values were generated on the power–voltage (P-V) curve, where the conventional MPPT technology could only track the local maximum power point (LMPP), hence the reduction in output power of PVMAs. Therefore, the IIBA-based MPPT was proposed in this paper to solve such issues and to ensure the capability of a PVMA in tracking the global maximum power point (GMPP) and utilization for enhancing the output power of a PVMA. Firstly, the Matlab/Simulink software was used to establish a boost converter model that simulated the actual 4-series–3-parallel PVMA under different shaded conditions, where the P-V curve with 1-peak, 2-peak, 3-peak and 4-peak values were generated. Subsequently, the tracking paces of the conventional bat algorithm (BA) were adjusted according to the gradient of the P-V curve for a PVMA. At the same time, 0.8 times the maximum power point (MPP) voltage Vmp under standard test conditions (STCs) for a PVMA was set as the initial tracking voltage. Lastly, the simulation results proved that under different environmental impacts, the proposed IIBA led to better performances in tracking both dynamic and steady responses. [ABSTRACT FROM AUTHOR]

This paper presents an improved version of the firefly algorithm (FA) by which a maximum power point (MPP) tracker was developed to track down the global maximum power point (GMPP) of a partially shaded photovoltaic module array (PVMA). As the first step, our team developed a high-voltage step-up converter where a coupled inductor was used to store the energy so that the duty cycle can be reduced so as to raise the voltage gain. The single-peaked P-V output characteristic curve of a PV array turns out to contain multiple peaks when the array is partially shaded. As a consequence, conventional MPP trackers occasionally track down a local maximum power point (LMPP), instead of the desired GMPP, and the output power of the array falls accordingly. Therefore, an improved version of the FA is proposed as a way to ensure that the GMPP can be tracked down in a more efficient way. Using the Matlab software, the MPP tracking performance of the proposed tracker was finally simulated in five scenarios. As it turned out, the proposed converter provided a high voltage gain at a relatively low duty cycle, and the improved version of the FA outperformed the original in terms of tracking time. [ABSTRACT FROM AUTHOR]

This paper is mainly concerned with the development of a variable-structure system (VSS) controller with model reference speed response for an induction motor drive. An indirect-field-oriented (IFO) induction motor drive is first implemented, and its dynamic model at a nominal operating condition is estimated from measured data. Then, a two-degrees-of-freedom linear model-following controller (2DOFLMFC) is designed to meet the prescribed tracking and load regulation speed responses at the nominal case. As the variations of system parameters and operating condition occur, the prescribed control specifications may not be satisfied further. To improve this, a VSS controller is developed to generate a compensation control signal to reduce the control performance degradation. The proposed VSS controller is easy to implement, since only the output variable is sensed. The existence condition of sliding-mode control is derived, and the chattering suppression during the static period is also considered. Good model-following tracking and load regulation speed responses are obtained by the designed VSS controller. Effectiveness of the proposed controller and the performance of the resulting drive system are confirmed by some simulation and measured results. Index Terms--Chattering suppression, induction motor, model reference control, speed control, variable-structure system.