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An exponential curve-based (ECB) control strategy has been proposed in this paper. The proposed ECB control strategy is based on the growth and decay of charge in the series RC circuit and the harmonic elimination by detecting the Fourier expansion series of the auxiliary equipment power supply system’s (AEPSS) three-phase output voltage level. It can quickly adjust each duty cycle to the best value for driving the isolated three-phase inverter (ITPI) and produce a three-phase 380 VAC/60 Hz output. A comparison of the AEPSS output performance using the traditional voltage cancellation method (VCM) and the proposed ECB control strategy was performed. The hardware implementation of the system was performed on the prototype developed in the laboratory. These control strategies are tested under three conditions, i.e., (i) Vi = 550 VDC. (ii) Vi = 750 VDC. (iii) Vi = 800 VDC. The total harmonic distortion (THD) is 13.7%, 14.5%, and 14.9%, and the output voltage Vo is 372.3 VAC, 377.3 VAC, and 385.3 VAC using the traditional control strategy at three test conditions, respectively. However, the THD is 7.2%, 7.8%, and 8.0%, and the output voltage Vo is 382.2 VAC, 381.2 VAC, and 381.9 VAC using the proposed ECB control strategy under the test conditions. It is obvious from the hardware results that the output voltage harmonics and output voltage level for the proposed ECB control strategy are superior to the traditional VCM. The voltage produced from the AEPSS using the proposed ECB control strategy is more stable and has better quality. In addition, the filter size is also reduced.

This study proposes a new isolated intelligent adjustable buck-boost (IIABB) converter with an intelligent control strategy that is suitable for regenerative energy systems with unsteady output voltages. It also serves as a reliable voltage source for loads such as battery systems, microgrids, etc. In addition, the hill climbing (HC) maximum power point tracking (MPPT) algorithm can be utilized with this innovative IIABB converter to capture the MPP and then enhance system performance. In this converter, five inductors (LA, LB, LC, LD, and LE) and four power MOSFETs (SA, SB, SC, and SD) are used in the proposed novel isolated intelligent adjustable buck-boost (IIABB) converter to adjust the applied voltage across the load side. It also has a constant, stable output voltage. The new IIABB converter is simulated and verified using MATLAB R2021b, and the performances of the proposed IIABB converter and conventional SEPIC converter are compared. The solar photovoltaic module output voltages of 20 V, 30 V, and 40 V are given as inputs to the proposed IIABB converter, and the total output voltage of the proposed converter is 48 V. In the new IIABB converter, the duty cycle of the power MOSFET has a small variation. The proposed IIABB converter has an efficiency of 92~99%. On the other hand, in the conventional SEPIC converter, the duty cycle of a power MOSFET varies greatly depending on the relationship between the output and input voltage, which deteriorates the efficiency of the converter. As a result, this research contributes to the development of a novel type of IIABB converter that may be employed in renewable energy systems to considerably increase system performance and reduce the cost and size of the system.

In this paper, a dynamic operational linear regulator (DOLR) based on a GaN high-electron-mobility transistor (HEMT) and wide-bandwidth operational amplifier was developed and implemented. The driving current could be regulated and controlled by the DOLR for 632 nm laser diodes. The constant-current mode for the continuous-wave laser and the pulse-width modulation (PWM) mode for the short-pulsed laser were realizable using this DOLR. This study focused on the rising-edge time change on the laser driving current when the DOLR was operated under the high-frequency PWM mode, because the parasitic components on the GaN HEMT, laser diodes, printed circuit board, and power wires could influence the current’s dynamic behavior. Therefore, the equivalent circuit models of the laser diode and GaN HEMT were applied to establish a DOLR simulation circuit in order to observe the rising-edge time change on the laser driving current. A DOLR prototype was achieved, and so experimental waveform measurements could be implemented to verify the DOLR simulation and operation.

This study aims to implement a single-stage differential boost inverter (SSDBI) applied in a single-stage battery energy storage system (BESS) topology that can supply power from a lower-voltage battery module to an alternating current (AC) load. Compared with the common two-stage topology, which has a two-stage converter and higher-voltage battery module array, the single-stage topology can reduce the number of cells and components and improve the power density. In addition, a modified sinusoidal pulse-width modulation (SPWM) control was proposed to reduce the control complexity of the SSDBI while improving the total harmonic distortion (THD) of the inverter. The modified SPWM control can reduce the duty ratio of the SSDBI and the stress on the components in order to improve the AC voltage output waveform and reduce the THD.

This article presents a novel buck–boost converter-based topology suitable for supercapacitors and grid-connected solar PV system applications. The proposed converter can handle a wide range of voltage variations at the input side, making it ideal for extracting most of the energy from supercapacitors or a solar PV system connected to the input side of the converter. The output voltage of the converter is non-inverting which makes the control easier. The design of passive components, continuous mode operation, and discontinuous mode operation are all thoroughly discussed. A low-power hardware prototype of three hundred watts is developed and tested in the laboratory to validate the theoretical aspects of the converter.

In this paper, the analysis and discussion are presented for two prominent types of wireless charging, namely inductive power transfer (IPT) and capacitive power transfer (CPT). The paper presents a comparative analysis between CPT and IPT. A comparison between different geometries of plates used in CPT is performed and it is shown that rectangular-shaped plates have the best power transfer efficiency. The effect of foreign particles between the capacitor plates of a single-module as well as a double-module CPT system on capacitance and energy transfer density are also investigated in the paper. The case of ceramic coating on the capacitor plates and its effects on the capacitance and energy transfer density with varying thickness are analyzed and presented. Different naturally occurring particles such as water, sand and wet sand have been simulated between the capacitor plates of the CPT system and their respective impact on power transfer is analyzed and the simulation results are demonstrated.

The traditional perturbation and observation (P&amp, O) maximum power point tracking (MPPT) algorithm of a structure is simple and low-cost. However, the P&amp, O algorithm is prone to divergence under solar radiation when the latter varies rapidly and the P&amp, O algorithm cannot track the maximum power point (MPP) under partial shading conditions (PSCs). This study proposes an algorithm from the P&amp, O algorithm combined with the solar radiation value detection scheme, where the solar radiation value detection is based on the solar photovoltaic (SPV) module equivalent conductance threshold control (CTC). While the proposed algorithm can immediately judge solar radiation, it also has suitable control strategies to achieve the high efficiency of MPPT especially for the rapid change in solar radiation and PSCs. In the actual test of the proposed algorithm and the P&amp, O algorithm, the MPPT efficiency of the proposed algorithm could reach 99% under solar radiation, which varies rapidly, and under PSCs. However, in the P&amp, O algorithm, the MPPT efficiency was 96% under solar radiation, which varies rapidly, while the MPPT efficiency was only 80% under PSCs. Furthermore, in verifying the experimental results, the proposed algorithm’s performance was higher than the P&amp, O algorithm.

This study implements a multifunctional charger based on a dual-switching, bidirectional flyback converter (DSBFC). The proposed charger adopts seven charging methods, including the incremental-current charging, constant-voltage (CV) charging, constant-current (CC) charging, pulse-current (PC) charging, triangular-current (TC) charging, sinusoidal-current (SC) charging, and positive/negative pulse-current (Reflex) charging methods. The charging process of a lithium-ion battery is divided into three stages: an initial term, a mid-term, and a final term. In the initial term, the incremental-current charging method is used in the initial term of charging for a soft start and to inhibit an increase in temperature. In the mid-term, five charging methods, including CC, PC, TC, SC, and Reflex-current charging, are used for charging. The CV charging method prevents overcharging the lithium-ion battery in the final term. Based on our experimental results, this study compares the four charging methods (PC, TC, SC, and Reflex-current) with the CC charging method to verify their improvement of the charging speed and increase in temperature in the mid-term. The charging speeds increased by 14.38%, 14.04%, 16.36%, and 27.27%, respectively, and the rise in temperature decreased by 37.8%, 40.5%, 48.6%, and 13.51%, respectively; all performed better than the CC charging method. Finally, users can adjust the charging method of the proposed DSBFC according to the needs of batteries so as to achieve excellent performance.

This study proposes a novel maximum power point tracking (MPPT) control strategy for the solar photovoltaic power system (SPPS). The proposed system adopts two solar photovoltaic modules of 430 W, which are connected to a boost converter and an MPPT controller, since the traditional MPPT algorithm (such as perturbation and observation [P&O] algorithm) can hardly reach maximum power point (MPP) under low irradiance level and partial shading conditions (PSC), which leads to the low efficiency of the SPPS. The speed of light optical path difference measurement (SLOPDM) MPPT control strategy has been developed in this study to overcome this problem. The estimation of the optical path angle difference is used as the basis for the proposed control strategy. This is done by determining the relationship between the optical path angle difference, solar photovoltaic power impedance Rspv and load Ro, and then calculating the duty cycle corresponding to the MPP, which then drives the boost converter to capture the MPP. The experimental results verify the proposed system, which shows the efficiency comparison between the SLOPDM MPPT algorithm, solar angle and horizon (SAH) algorithm, and P&O algorithm under PSC and uniform irradiance conditions (UIC) at irradiance levels of 700 W/m2 and 65 W/m2. It is evident from the comparison that the efficiency of the SLOPDM MPPT algorithm is 99% under both conditions, which is higher than the SAH and P&O algorithms. The SLOPDM MPPT algorithm can precisely, rapidly, and stably be operated at MPP. The contribution of this study is that the proposed MPPT control strategy can help achieve the high−performance of SPPS without changing the hardware circuit design and requiring any additional solar power meter. This reduces the cost and the complexity of the system significantly.

This research proposed a novel global maximum power point tracking (global-MPPT) algorithm. The proposed algorithm eliminates the perturbation and observation (P&O) technique disturbance problem that the power point will be stuck at the local peak power point under a partial shading condition (PSC). The proposed global-MPPT algorithm detects the photovoltaic module (PV-M) environment irradiance level by the relationship between the output power and voltage of the PV-M. In the proposed algorithm, the important parameter w is determined by the PV-M output power and irradiance level, which is also the compensation parameter that corresponds to the relationship of temperature. The proposed global-MPPT algorithm is aimed to predict the best duty cycle of the global-MPPT based on the irradiance level, parameter w, PV-M output voltage, and load, and then achieve the maximum power point (MPP) quickly and accurately. The measurement results under UIC and PSC verify that the proposed global-MPPT technique performs better than the particle swarm optimization (PSO) and P&O techniques. This research contributes to the proposed method that can find the global-MPP in time based on the irradiance level, temperature, and load.