Harmonic pollution has a major detrimental effect on the power quality of low voltage distribution networks as a result of the proliferation of non-linear loads. The filter injects compensating current equal to the harmonic current needed by non-linear loads at the point of common coupling. Progressive harmonic compensation can be achieved by using shunt active filters at the metering point of each non-linear consumer. This paper proposes a modification in the control scheme of filter based on resistive load synthesis approach. The analysis of the proposed method is carried out in MATLAB Simulink. The control algorithm is used to calculate the filter current by identifying the harmonic current contribution of source at each consumer location. The efficiency of the suggested method in enhancing power quality of system is validated by real time simulation using OPAL-RT.

In this parper we consider an Alpazur oscillator which consists of a Rayleigh-type oscillator and a DC power supply controlled by a switch that modifies the operating mode. The oscillator denotes some special phenomena in some parameter settings and are called chaos or bifurcation. In addition, we observe the behavior of this oscillator over a wide rage of parameter variation. Chaos theory tools such as, bifurcation, phase portrait, poincaré section and Matching Energy (ME) was examined in the analysis of dynamic of the system. Simulations were carried out using the 4th-order Runge-Kutta algoritm in Matlab. The results shows that Alpazur oscillator is sensitive to parameter variation and exhibts a wide range dynamics from fundamental periodicty to chaos.

The work elucidated in this scientific article presents a novel non-isolated high gain switched capacitor (HGSC) DC-DC converter engulfed for carbon neutral energy applications. A hybrid utilization of complementary switching approach switches enables simplified control and high voltage gain of HGSC even at low duty cycle owing to the switched capacitor along with boost inductors. Further, the proposed structure also features high efficacy, reduced voltage stress and current stress on semiconductor switching devices. The proposed HGSC DC-DC converter principle of operation along with the steady-state analysis and different switching stages were discussed in detail. Small signal analysis has been performed to analyze the stability of the proposed converter, whereas an averaging technique is performed to know its dynamics performance. Furthermore, the converter is thoroughly analyzed in terms of power losses. For comparing the practical efficiency of the designed converter, non-idealities voltage gain is derived. The efficiency of the proposed converter is validated practically and extensive performance comparison is carried out with other solutions in the literature. When a supply of input voltage 20 V feed into the proposed converter. It produces an output voltage of 140 V to 240 V output. A 200W laboratory proto model is developed; accordingly conducted extensive experimental analysis to validate the feasibility of the proposed HGSC DC-DC converter topology.

The double-line frequency ripple power exists inherently in single-phase power converters. To address this problem, active power decoupling technique (APD) is widely used. It diverts the ripple power into a small energy storage element through introducing passive and active power devices. This inevitably involves more voltage and current sensors for corresponding control, which raises the cost while decreasing reliability and power density. In this paper, a Lyapunov-based methodology is proposed to achieve APD control without adding any sensor. According to the designed controller laws, the practical decoupling capacitor voltage will converge to its reference. The decoupling voltage reference is given by taking into account buffering the double-line frequency ripple power. Afterwards, the robustness against parameter perturbations of the proposed method is discussed. Finally, the experimental results verify the feasibility of the proposed control strategy.

The long transmission distance in wireless power transmission(WPT) system will lead to a sharp decline in transmission efficiency, this paper presents a novel ortho-octagonal double helix metamaterial that can effectively enhance the transmission efficiency of WPT systems, theoretically derived and experimentally verified the enhancement of evanescent wave transmission by this metamaterial dielectric plate. A WPT simulation system operating at 10.78 MHz is constructed by HFSS software, and the effects of adding passive relay coils and different shapes of metamaterials on the transmission efficiency are comparatively investigated. Both simulation and experimental results show that the transmission efficiency of the WPT system can be improved to different degrees after inserting different shapes of metamaterials at the transceiver end of the system. When the transceiver coil spacing of the WPT system is greater than 22 cm, the effect of metamaterials on the system transmission efficiency enhancement shows an increasing and then decreasing trend as the distance increases. The positive octagonal metamaterial improves 12% over the circular metamaterial in the mid-range transmission distance due to its better magnetic coupling effect. When the transceiver coil spacing is 22 cm, the open-circuit voltage of the receiving coil after loading the metamaterial is stabilized to be enhanced by nearly 5 times, and it has the best effect at 30 cm, and the transmission efficiency is enhanced from 30% to 60%, which verifies the effective enhancement of the metamaterial on the transmission efficiency of the WPT system.

This paper proposes a fully integrated low dropout (LDO) regulator with gate-couple flipped voltage follower(GC-FVF). The proposed GC-FVF addresses the limited output swing issue of conventional PMOS FVF in LDOs while maintaining a low output impedance. Besides, this LDO introduces a cascode compensation loop, which, along with the low output impedance of GC-FVF, pushes the output pole far away from the unity-gain bandwidth under both light and heavy load conditions. Consequently, the LDO becomes a stable two-pole system, supporting a high loop gain of up to 100dB and significantly enhancing the load and line regulation. Key specifications include a preset output voltage of 1.8V, a minimum unregulated input voltage of 2V, a maximum output current of 100mA, a ground current of 32μA, and an active chip area of 260μm×180μm. Notably, this LDO achieves high load regulation of 4.8μV/mA and high line regulation of 13.8μV/V without the need for off-chip capacitors.

As the increasing demands for the constant voltage (CV) charging of multiple loads, this article proposes an LC compensated wireless power transfer (WPT) system with multiple CV outputs function. The proposed WPT system can achieve multiple voltage outputs without decoupling method. Each voltage output channel is composed of a compensation capacitor and a compensation inductor connected in series. By configuring different compensation inductors and capacitors for each output channel, it can achieve different CV outputs without affecting the output voltage of other output channels. In addition, the system can achieve near-zero phase angle (ZPA) and zero-voltage switching (ZVS) operations, which can improve system efficiency. Finally, the correctness and rationality of the proposed WPT system is verified by built an experimental prototype with two CV output channels.

Accurate estimation of lithium-ion battery state of energy (SOE) is an important prerequisite for prolonging battery life and ensuring battery safety. To achieve a high-precision estimation of SOE, this study focuses on ternary lithium-ion batteries and proposes an SOE estimation method that combines limited-memory recursive least squares (LM-RLS) with strong tracking adaptive window Multi-innovation cubature Kalman filtering (STF-MCKF). A finite set of data is used for model parameter updates at the current time to solve the problem of data saturation and improve the identification accuracy of the RLS algorithm. By utilizing the STF algorithm, the CKF algorithm is optimized to enhance its robustness under strong disturbances. An adaptive window Multi-innovation strategy is proposed to improve the accuracy of SOE estimation and the stability of the CKF algorithm while maintaining a balance between computational complexity and estimation accuracy. To validate the effectiveness of the algorithm, experiments are conducted under DST and BBDST conditions. The results show that the STF-MCKF algorithm has a maximum convergence time of 4s and an SOE estimation error within 1.04% under DST conditions. Under BBDST conditions, the STF-MCKF algorithm has a maximum convergence time of 3s and an SOE estimation error within 2.34%. Furthermore, the STF-MCKF algorithm demonstrates good stability under both the two conditions, indicating the effectiveness of the proposed improved algorithm for lithium battery SOE estimation.

The demand for wireless power transfer (WPT) systems that can maintain a constant voltage output (CVO)characteristic is gradually increasing in some practical application areas of WPT, such as industrial power supplies. However, existing CVO-type systems are often limited by the parameter design of the loosely coupled transformer (LCT) and the configuration of the receiver side is not compact enough. Therefore, this paper proposes a strongly coupled system with CVO function composed of capacitor-inductor-capacitor-none (CLC-N) topology. The system’s primary side uses a CLC compensation, while the secondary side conforms to a minimalist design without the need for compensation components such as capacitors and inductors. The initial segment of the paper pertains to the discussion of the conditions required to satisfy both zero-phase-angle (ZPA) and CVO functionality of the suggested system. Subsequently, an in-depth approach to parameter design is outlined, accentuating that the output voltage remains unrestricted by the LCT’s parameters. Additionally, this paper examines the realization of zero-voltage switching (ZVS) within the suggested system, as well as the influence that variations in compensation components have on the CVO function. To underscore the benefits of the suggested CVO-type WPT system that employs CLC-N compensation, the paper presents a comparison with a range of other CVO-type WPT systems. Ultimately, an experimental prototype is fabricated to test the theoretical framework, and the results from these experiments confirm the feasibility of the suggested CVO-type WPT system based on CLC-N compensation.

This paper presents a shadow signal generator that produces square and triangular waveforms. The oscillator frequency can be changed using an external circuit (shadow oscillator). This method will make the conversion speed better than the conventional oscillators. The technique is based on utilizing an external circuit to modify the comparator’s tripping point. The circuit is built using widely available commercial integrated circuits, 1% accurate resistors, and DC supplies with a ±5V voltage. The recommended setup is suitable for instrumentation where the oscillation frequency is directly proportional to the variation in the resistance of the sensor. The functionality of the proposed design was confirmed by experimentation and simulation. The oscillation’s frequency can be changed to be nearly 10 times greater than its starting value, according to the results.

Despite the performed progressive research work, the interpretation of negative group delay (NGD) function remains not familiar to non-specialist design and fabrication circuit engineers. The functionality misunderstanding limits the NGD circuit applications compared to other classical electronic functions. The present paper is dealing on the design of tunable property circuit by operating with positive and negative delay behaviors. The topology of the tunable circuit by using low-pass (LP) type NGD one is described. The design formulas for calculating the circuit resistor and capacitor parameters from the desired delay are expressed. The design feasibility of the tunable circuit composed of LP-NGD cell and RC-circuit is validated with a proof-of-concept (PoC) implemented on a test board. Two different signals with pulse and arbitrary waveforms having tens-milliseconds duration were considered during the validation tests. As expected by tuning a varistor from 0.4 kΩ to 1 kΩ, the negative delay behavior varying from about -0.4 ms was verified thanks to the time-advanced effect due to the LP-NGD property. Then, the output signal delay was observed to become positive when the varistor is tuned from 1 kΩ to 3 kΩ.

This paper presents the development of an interleaved bidirectional DC-DC converter with single-phase high-frequency isolation associated with two different pulse width modulations (PWM), one for each power flow direction. The converter stages analysis, DC voltage gains expressions, and voltage/current stresses in CCM are presented. The proposed converter advantages are new modulation, the current ripple frequency and voltage in two ports is four times higher than the switching frequency, volume and weight reduction of passive elements, and balanced current distribution between the legs. Besides, the single-phase transformer that provides galvanic isolation between the DC bus and the battery or supercapacitor. An experimental prototype is implemented in the laboratory to validate the mathematical and theoretical analysis for both energy flow senses under the test conditions at converter-rated power 2.5kW, Low voltage side 180V, and high voltage side 380V.

Multi module isolated converters (MMICs) find extensive application in various DC-DC applications due to their remarkable features of galvanic isolation, bi-directional power flow, high power density and enhanced efficiency. However, voltage and current sharing among the converter modules are the most significant issues in MMICs. This paper proposes Multi-port Integrated-Magnetics Transformers (MpIMTs) which address the input-output DC-link voltage imbalances within an ISOS converter. The proposed transformers ensure the input voltage sharing (IVS) and output voltage sharing (OVS) through balancing windings within their structures, thus substitutes the complicated active control scheme with the balancing winding. Besides, the input side and output side modules are decoupled from each other, thus the impact of parameters variation and inter-module energy transfer during a transient of one side does not reflect to the other side. These properties are achieved by proposing a custom-designed core and an off the shelf available U core assembled MpIMTs. The magnetic and electrical equivalent along with the design criteria of the balancing winding are also presented. Furthermore, the paper includes the comparative analysis of the proposed transformers which reveals that while the U-core MpIMT offers simplified construction, it comes at the expense of slightly reduced efficiency compared to the custom-designed MpIMT. Finally, the proposed U core MpIMT is validated through a laboratory prototype.

Wireless power transfer (WPT) system in seawater exhibits distinct transmission characteristics from those in air due to the unique properties of seawater medium and the complexity of the seawater environment. In this paper, a 2-transmitter (2TX) and 1-receiver (1RX) WPT system in the frequency band of 350~550 kHz in seawater is observed. When the transfer distance is at midrange, the maximum load voltage point of the system is shifted from 460 kHz to 430 kHz compared to that in air, and the maximum transfer efficiency is 7 times of that in air. The system maintains a stable output voltage when the receiving coil is at different offsets. To grasp the influence mechanism of seawater on wireless power transfer, two new parameters, complex self-inductance and complex mutual inductance, are introduced into the circuit model to summarize the propagation of electromagnetic waves in attenuating medium, and the model is verified through experiments.

This paper introduces a new non-isolated double-input triple-output (DITO) high voltage gain DC-DC converter with a wide range of applications, including hybrid voltage source systems, solar home appliances, dc bus power distribution systems, and electrical vehicles (EV). The proposed DITO converter interfaces two hybrid voltage sources to supply three different output loads with varying voltage and power levels. Compared to conventional converters of the same type, the proposed DITO converter offers several advantages, including operation for all duty cycles, integration of hybrid energy sources to transfer power to multiple loads, high voltage conversion ratio for all three output ports, a higher ratio of total voltage gain to total components number, common grounded input and output DC ports, simultaneous DC voltage regulation of three output ports by tuning separate controlling parameters of duty cycles, an additional turn ratio of coupled inductors to increase the voltage gain of output ports, and medium voltage stress on switches. The proposed DITO converter utilizes a new single-switch single-coupled-inductor DC-DC structure, which is analyzed and verified through a prototype implementation for 25V and 30V input voltages and 210V, 330V, and 400V output voltages with a total power of 480W. The experimental results confirm the simulation results and theoretical analysis.

A document by Zisong Mo. Click on the document to view its contents.

Among the power inverters, modular multilevel converters (MMC) have gained popularity due to their advantages over conventional two-level inverters. Although the MMC utilizes more power switches than traditional inverters, the former exhibits notable benefits such as low total harmonic distortion, low switching losses with lower voltage stress, high power quality, reduced electromagnetic interface, and modularity with numerous degrees of freedom to synthesize output waveforms. Concerning the synthesized voltage quality, several low-frequency modulation techniques have been proposed to produce output voltage with low harmonic content. A particular case of study consisting of a three-phase even-level MMC inverter is taken as a benchmark to comparatively evaluate four methods for synthesizing high-quality output voltage. The employed techniques are ( i) selective harmonic elimination (SHE), ( ii) generalized SHE, ( iii) THD Voltage Minimization, and ( iv) Optimum Nearest Level Modulation, selected based on the phase and line-to-line output voltage THD. The model is formulated to compute the commutating angles to control the MMC submodules. Simulations show individual performance under the same operating conditions. A lab-scale prototype is built to corroborate the theoretical approach. The results allow the selection of the most convenient modulation technique based on the number of commutations and harmonic spectrum.

Brushless DC motor (BLDCM) is widely used in aerospace equipment. But the neuter port in conventional BLDCM windings could lead to torque ripples and low reliability. Each phase winding of the open winding BLDC is connected to an H-bridge inverter, and its phase voltage and phase current could be controlled independently, which has a certain fault tolerance. Firstly, the circuit topology and conduction mode of the open-winding brushless DC motor are introduced, and a Matlab simulation model is established according to the mathematical equation of the motor. Then, the operation characteristics of the open winding brushless DC motor with power device failure are analyzed, and the characteristics of two fault-tolerant control methods, compensation and reconstruction, are discussed. Finally, the open winding brushless DC motor and controller are processed, and the experimental platform is built to verify the operation characteristics of the open winding brushless DC motor with normal operation and compensation operation.