Constant Output Voltage Research Articles

Robust PWM control scheme for switched-capacitor MLI with leakage current suppression in grid-connected renewable energy application

Typically, parasitic capacitances exist between the ground and the solar panel terminals in grid-connected PV systems. These parasitic capacitances provide a path for a leakage current, which leads to significant safety concerns, observable and seriously hazardous harmonic orders aligned with the injected grid current, and significant safety difficulties. In this research, a robust PWM controlling method that used competently in reducing the level of the leakage current and improving the power quality of a switched-capacitor Multilevel Inverter. This technique creates developed reference signals from the main signal to generate the switching scheme for the converter circuit. Additionally, the suggested control strategy only works with a small number of carrier signals, resulting in a quick system response and a simpler controller algorithm. Likewise, this controlling approach offers a stable way to maintain a constant output voltage in the suggested converter by adjusting the switching capacitors' voltages, which is not possible with traditional control techniques. MATLAB/Simulink is used to simulate the outcomes for both the suggested control approach and the traditional Phase Disposition (PD) PWM control method whereas the leakage current component reduces to 25 % compared to the captured component with the PDPWM. The simulation and the practical results based on the dSPACE-1103 hardware are quite similar.

Hybrid Topology with Reconfigurable Rectifier for Enable CC and CV Output Characteristics in Wireless Power Transfer Systems

To achieve simple and reliable conversion from constant current (CC) charging mode to constant voltage (CV) charging mode in wireless power transfer systems, this paper proposes a hybrid topology equipped with a reconfigurable rectifier. An AC switch is adapted to simultaneously realize the change from half-bridge rectification to full-bridge rectification and achieve the shift from a topology with capacitors in the series compensated primary and secondary sides to a topology with capacitors in the series compensated primary side and the inductor-capacitor-inductor (LCL) compensated secondary side. Notably, communication between the transmitter and receiver sides is not necessary in the proposed method. Furthermore, the zero phase angle characteristic is successfully maintained in both charging modes. The experimental results obtained using the 48 V/0.7 A experimental prototype, which was built to validate the relevant theoretical analysis, show that output current/voltage can be achieved in CC/CV charging mode independent of load resistance. Notably, the maximum power transfer efficiency of the system during the charging process reached 95.33%.

Analysis and design of wireless power transfer system with anti-misalignment constant voltage output characteristics

PurposeThis study aims to solve the problem of high output voltage fluctuation and low efficiency caused by the misalignment of the magnetic coupling structure in the wireless charging system for electric vehicles. To address these issues, this paper proposes a dual LCC-S wireless power transfer (WPT) system based on the double-D double-layer quadrature (DDDQ) coil, which can realize the anti-misalignment constant voltage output of the system.Design/methodology/approachFirst, this paper establishes the equivalent circuit of a WPT system based on dual LCC-S compensation topology and analyzes its constant-voltage output characteristics and the relationship between system transmission efficiency and coupling coefficient. 1. Quadruple D (Ahmad et al., 2019) and double-D quadrature pad (DDQP) (Chen et al., 2019) coils have good anti-misalignment in the transverse and longitudinal directions, but the magnetic induction intensity in the center of the coils is weak, making it difficult for the receiving coil to effectively couple to the magnetic field energy. 2. Based on the double-D quadrature (DDQ) structure coil that can eliminate the mutual inductance between coupling coils and cross-coupling, Gong et al. (2022a) proposed a parameter optimized LCC-LC series-parallel hybrid topology circuit, which ensures that the output current fluctuation is controlled within 5% only when the system is misaligned within the 50% range along the X direction, achieving constant current output with anti-misalignment. The magnetic coupling structure’s finite element simulation model is established to analyze the change in magnetic induction intensity and the system’s anti-misalignment characteristics when the coil offsets along the x and y axes. Finally, an experimental prototype is developed to verify the constant voltage output performance and anti-misalignment performance of the system, and the proposed anti-misalignment system is compared with the systems in existing literature, highlighting the advantages of this design.FindingsThe experimental results show that the system can achieve a constant voltage output of 48V under a time-varying load, and the output voltage fluctuates within ±5% of the set value within the range of ±60 mm lateral misalignment and ±72 mm longitudinal misalignment.Originality/valueBased on the dual LCC-S WPT system, the mutual inductance between the same side coils is reduced by adding decoupling coils, and the anti-misalignment characteristics and output power of the system are improved in a certain range. It is aimed at improving the stability of the system output and transmission efficiency.

Design and development of an LC compensated WPT system with multiple constant voltage outputs function

SummaryWith the increasing demand for the constant voltage (CV) charging of multiple loads, this article proposes an LC compensated wireless power transfer (WPT) system with multiple load‐independent CV outputs function. Each transmission channel consists of a compensation capacitor and a compensation inductor forming a resonant loop. By configuring different combinations of compensation inductor and capacitor for each transmission channel, different CV outputs can be achieved without affecting the output voltages of other transmission channels. In addition, the proposed system can achieve near zero phase angle (ZPA) and zero‐voltage switching (ZVS) operations, thereby improving system efficiency. Firstly, a detailed theoretical derivation of the proposed system with multiple load‐independent CV outputs and ZPA operation is performed, and the detailed parameter design process is provided. Secondly, the implementation method of ZVS operation is introduced and verified through simulation. Finally, an experimental prototype of two transmission channels is taken as an example to verify the correctness and rationality of the proposed system.

Empirical Investigation of a Single-phase Input Switched AC-DC Boost Converter with Improved Power Quality

The Boost converter topology is most widely used for power factor correction (PFC) converters. The conventional passive Boost PFC converter inherently suffers from the lack of controllability and non-ideal characteristics of the diode-bridge rectifier. Replacing diodes with active switch(es) offers viable solutions but increases the circuit complexity. Addressing this trade-off, a novel design of a single–phase input switched AC to DC Boost converter has been presented in this article. The active switch of the Boost DC converter is shifted to the input side of the full-bridge diode rectifier which provides more control on the input current without increasing much of the circuit complexity. Two Boost inductors and two output split capacitors are used for providing higher step-up operation compared to the conventional. The converter has been simulated both in open-loop and closed-loop conditions using the PSIM software. The simulation results show that the proposed converter provides good dynamic response and can maintain a constant stable output voltage during sudden load change. Furthermore, to evaluate the experimental performance of the suggested converter, a prototype converter has been developed. A scaled-down experiment has been performed which shows that the converter can achieve up to 85.2 % efficiency and an input power factor of 0.9.

Mutual Inductance Identification and Bilateral Cooperation Control Strategy for MCR-BE System

Considering that the excitation method of an electric excitation synchronous motor has the disadvantages of the brush and slip ring, this article proposes a new brushless excitation system, which includes two parts: a wireless charging system and a motor. To meet the requirements of maximum transmission efficiency and constant voltage output of the system, a bilateral cooperation control strategy is proposed. For the strategy, the buck converter in the receiving side of the system can maintain maximum transmission efficiency through impedance matching, while the inverter in the transmitting side can keep the output voltage constant through phase shift modulation. In the control process, considering that the offset of coupling coils will affect the control results, a grey wolf optimization–particle swarm optimization algorithm is proposed to identify mutual inductance. Simulation and experimental results show that this identification algorithm can improve the identification accuracy and maximize the avoidance of falling into local optima. The final experimental result shows that the bilateral cooperation control strategy can maintain the output voltage around 48 V and the transmission efficiency around 84.5%, which meets the expected requirements.

High-Efficiency WPT Systems for Potable Electronics Based on DC-Bias-Voltage- Controlled Variable Capacitor

The power density of wireless power transfer (WPT) systems employed in portable electronics can be enhanced by increasing the operating frequency, but at the expense of lower efficiency due to increased switching and parasitic losses. This paper proposes a method, based on the DC-bias-voltage-controlled variable capacitor (VC) and variable frequency (VF) regulation, to improve the overall efficiency of the WPT system for portable electronics. The method uses VC on the primary side to detune the resonant tank and dynamically regulate the output power, while VF is employed to improve the system efficiency using a look-up table based on a power loss model. A DC bias voltage control module with self-supply ability is employed to control the equivalent capacitance of the VC. A control strategy is proposed to regulate both VC and VF. Experimental results of a 150W prototype are presented to demonstrate that constant output voltage can be maintained despite a wide load range, with an overall efficiency range of 82.1% (@25W) and 92.2% (@150W).

Investigation on the Effect of Parasitic Elements on PID Control of DC-DC Buck Converter

DC-DC converter circuits are used in many electronic devices to adjust the voltage to a certain level such as Electric Vehicle. DC-DC Buck converters, which are the most used type of DC-DC converters, reduce the input voltage and keep the output voltage constant at a desired reference voltage value. In this study, the effect of parasitic elements in Buck DC-DC converters is examined on the PID controllers. Parasitic elements cause a non-linear effect on the Buck converter system model. Studies in the literature generally control the output voltage by designing controllers on the Buck converter model without parasitic elements. Alternatively, linear controllers such as PID are designed according to the linearizing model, taking into account the effect of parasitic elements. In addition, nonlinear controllers are designed on the full model with the effect of parasitic elements. In this study, the effect of parasitic elements on linear controllers, especially PID, is examined.

Switchable-coupled-inductor input-regulated Class-E converter at fixed 50%-duty-cycle 1-MHz switching signal

To achieve simple topology and easy controllability, this paper presents a Class-E converter adopting the proposed switchable-coupled-inductor input-regulating (SCI-IR) method to achieve a constant output voltage under variable inputs. In comparison to other regulating or control schemes, this method features a simple circuit structure and incurs negligible power losses during the input-regulation process. By analysing the circuits with resonance tank at steady-state operations, we formulate the SCI-IR design parameters and procedures, and demonstrated experimentally with a Class-E at fixed 50%-duty-cycle 1-MHz switch signal. The measurement reveals that the prototype supports input-regulation with voltage range from 12V to 16V, and delivers the targeted constant output voltage/power of 10V/1W. At all input conditions, the converter remains in the zero-voltage-switching operation and obtains a conversion efficiency of better than 76.2 %.

A Control Strategy for Achieving Constant Voltage Output with an Extensive ZVS Operating Range in Bidirectional Wireless EV Charging Systems

Variations in the coupling coefficient of loosely coupled transformers and dynamic loads have a significant impact on the overall performance of bidirectional inductive power transfer (BIPT) systems. However, a wide range of load and coupling coefficient variations are common in the actual charging process, which may cause the converter on both sides to operate in a hard switching state, resulting in switching noise, reduced efficiency, and potential safety concerns. In this paper, a triple-phase-shift control (TPSC) strategy is proposed to study the zero-voltage switching (ZVS) operating range and constant-voltage output (CVO) characteristics of the double-side-LCC (DS-LCC) topology. To ensure a CVO over the wide range of coupling coefficient variations, a dual-phase-shift control is introduced for AC voltage matching. Based on this, the third phase-shift angle control between the converters on both sides is introduced to ensure the ZVS realization. Meanwhile, the time-domain model is developed to analyze the rationality of the proposed third phase-shift angle and the ZVS operating range. Finally, the effectiveness of the proposed TPSC strategy is validated through a 1.5 kW experimental prototype with an air gap of 100–150 mm.

An on-chip soft-start pseudo-current hysteresis-controlled buck converter for automotive applications

This paper introduces a novel direct current to direct current (DC-DC) buck converter that uses a pseudo-current hysteresis controller and an on-chip soft start circuit for improved transient performance in automotive applications. The proposed converter, implemented with Taiwan semiconductor manufacturing company (TSMC) 0.18 µm complementary metal oxide semiconductor (CMOS) one-poly-six-metal (1P6M) technology, includes a rail-to-rail current detection circuit and an on-chip soft start circuit to handle transient responses and improve efficiency. Transient response analysis shows fast settling times of 28 µs for both load current changes from 100 mA to 1 A and reversals with consistent transient voltages of approximately 190 mV and peak power efficiency of 99.32% at 5 V output voltage and 100 mA load current. Additionally, the converter maintains a constant output voltage of approximately 5 V across the entire load current range with an average accuracy of 90.41%. A comparative analysis with previous work shows superior performance in terms of figure of merit (FOM). Overall, the proposed pseudo-current hysteresis controlled buck converter exhibits remarkable transient response, load regulation and power efficiency, positioning it as a promising solution for demanding applications, particularly in automotive systems where precise voltage regulation is crucial.

Design and Analysis of an H-Type Pickup for Multi-Segment Wireless Power Transfer Systems

To tackle the complex wireless power supply requirements in the Automated Material Handling System (AMHS) of semiconductor wafer factories, this paper presents a design method for a magnetic coupling mechanism based on a Multi-Segment Wireless Power Transfer (MSWPT) system for dynamic wireless power supply in segmented track configurations. Firstly, the track is approached using Inductive Power Transfer (IPT) technology combined with an LCC-S resonant structure transmitter (Tx). Following this, the feasibility of the H-type pickup is assessed through magnetic and electrical circuit analyses, which leads to the preliminary determination of the pickup dimensions by means of finite element magnetic and thermal simulations. Furthermore, an analysis of the mutual inductance drop is conducted under various track structure parameters during track crossing and curve negotiation operation conditions. Secondly, a dual-coil winding method is proposed to reduce the insulation stress on the PCB board. Additionally, a method for calculating the wire length and a design process for the overall parameters of the pickup are derived. Finally, two Txs and a 1.5 kW power receiver (Rx) were designed to verify the mutual inductance fall under the aforementioned conditions. During low-speed full-load operations, a constant-voltage output was achieved through the proposed dual-loop PI control strategy, thereby meeting the requirements for a constant-voltage output in industrial applications.

Wind Energy Conversion System using Cascading H-Bridge Multilevel Inverter in High Ripple Scenario

This paper presents wind energy conversion system using CHB MLI and phase interleaved boost converter to overcome high voltage and current ripple. Developments in power electronics technology have a direct impact on advances in wind energy conversion systems. WECS output voltage may fluctuate depending on wind speed. For WECS to maintain a constant output voltage, a power converter is required. This paper explains how to configure a phase-interleaved boost converter and voltage controller to maintain a stable intermediate circuit voltage in the system. The proposed cascading H-bridge multilevel inverter (CHB MLI) converts DC/AC using a novel topology. Separate DC sources are not utilizing the suggested topology. Multi-level inverters are operated by specific harmonic disposal pulse width modulation, or SHE-PWM are utilized. PMSG voltage, CHB-MLI voltage, boost converter voltage and rotor speed have seven different levels of simulated waveforms. Among the many advantages of three-phase alternating DC-DC boost converters, that are high efficiency, fast dynamics and very low current ripple. The output voltage is increased to 400 V using a three-phase interleaving converter, which also maintains a higher efficiency of about 98%. DC-DC power converters have proven to be essential components of many applications and topologies. The interleaving technique is necessary to address the main disadvantages of DC-DC power converters: increased voltage, reduced efficiency, and rippled current. Interleaved boost converters have several advantages, including lower switching losses, lower voltage and current ripple, increased efficiency, and more. To improve the converter's overall functionality, the "n" parallel converter is connected through an interleaved boost converter. This paper presents a performance analysis of a multiphase alternating boost converter to reduce high voltage and current ripple. MATLAB/Simulink is used for analysis and simulation of phase-interleaved boost converters.

A Single-Switch WPT Circuit With Inherent CCO–CVO for Battery Charging

In order to obtain a highly reliable and low-cost wireless charging method. This paper proposes a single-switch wireless power transfer (WPT) circuit with inherent constant current output (CCO) and constant voltage output (CVO) for battery charging. Compared with a full bridge WPT circuit, the structure and control strategy of the proposed circuit is simple. And the shoot-through problem could be avoided in the proposed circuit. In order to realize the inherent CCO-CVO without the wireless communication and extra control circuit, the double-D quadrature (DDQ) coils are used in this paper to remove cross-coupling between coils. And the corresponding compensation network is designed to realize the automatic transition from the CCO to CVO. There are no active control schemes used in the proposed method. The compensation design could enable primary-side protection of over-current against the accidental removal of the secondary side. There is no compensation inductor in the secondary circuit, which reduces the volume and weight of the secondary circuit. Moreover, the transfer gain does not rely on the transformer parameters, and more parameters design freedom can be realized. Finally, the simulation and the experimental verification are carried out to verify the superiority of the proposed circuit.

Efficient and Reliable Fast Charging Station for Electric Vehicles: Integrating PV System and Optimized Control

In this study, an innovative electric vehicle (EV) charging station that integrates multiple energy sources for efficient EV charging is introduced. It combines photovoltaic (PV) panels, a battery storage system, and grid connectivity to ensure reliable and sustainable charging. The PV panels act as the primary source of clean and renewable energy, prioritizing PV energy for EV charging to reduce grid reliance and promote eco-friendly charging. A modified bidirectional Zeta-KY converter is utilized to maintain a constant output voltage, with a chaotic dragonfly optimized PI controller for precise regulation. During periods of insufficient PV power, the bidirectional converter steps down grid power for EV charging. The flow of grid power to the EV station’s battery is managed by a dynamic power source management algorithm for uninterrupted power availability. The efficacy of the design is demonstrated through comprehensive simulation and experimental outcomes. The suggested converter outperforms other counterparts, achieving peak efficiencies of 97% in boost mode and 96.8% in buck mode. A comparative analysis of controllers reveals that the Chaotic Dragonfly optimized PI controller excels with a low settling time of 0.10 sec, zero overshoot, rapid rise time, and a low steady-state error of 0.1%.

A Hybrid-Frequency-Based Multi-Load Wireless Power Transfer System With Constant Current or Voltage Outputs

A Hybrid-Frequency-Based Multi-Load Wireless Power Transfer System With Constant Current or Voltage Outputs

Approach to the Modeling of LDO-Assisted DC-DC Voltage Linear Regulators

This paper presents the design of a LDO-assisted DC-DC converters in Cadence Virtuoso based on a 350-nm CMOS technology. This kind of voltage regulators consists of a switching converter together with a classic or LDO (low drop out) linear voltage regulator. While the linear regulator provides the constant output voltage, the switching converter conducts nearly all the current provided in the output load, and keeping the regulator current close to zero where the higher efficiency is achieved. In addition, current article shows the modeling in Matlab/Simulink. This modeling is mandatory in order to predict and assure the stability of the circuit. In addition, it can allow improving the performance of the circuit.

Self-Heating Induced Instability of a Non-Linear Inductor in a SMPS: a Case Study

This paper proposes a case study to show that the non-linear operation of a power inductor in a SMPS can induce instability of the control system leading to overheating of the inductor beyond its allowable temperature and to an excessive peak of the maximum current. The case study is performed by a commercial ferrite inductor employed in a synchronous boost converter encompassing a control system to adjust the duty cycle, assuring a constant output voltage. The thermal transient is described by the time domain waveforms and thermal images.

A Single-Stage IPT Converter with Optimal Efficiency Tracking and Constant Voltage Output Against Dynamic Variations of Coupling and Load

A Single-Stage IPT Converter with Optimal Efficiency Tracking and Constant Voltage Output Against Dynamic Variations of Coupling and Load

Self-Tuning WPT System With Constant Voltage Output Under Resonance Frequency Shift

Self-Tuning WPT System With Constant Voltage Output Under Resonance Frequency Shift