Triboelectric nanogenerator with mechanical switch and clamp circuit for low ripple output

For new renewable clean energy,triboelectric nanogenerators(TENGs)have shown great potential in response to the world energy crisis.Nevertheless,the alternating-current signal generated by a TENG needs to be converted into a direct-current signal to be effective in applications.Therefore,a power management circuit,comprising a clamp rectifier circuit and a mechanical switch,is proposed for the conversion and produces a signal having a low ripple coefficient.The power management circuit adopts a clamp circuit as the rectifier circuit to increase the rectified voltage,and reduces the loss resulted from the components by reducing the use of discrete components;the electronic switch in the buck regulator circuit is replaced with a mechanical switch to reduce cost and complexity.In a series of experiments,this power management circuit displayed a stable output voltage with a ripple voltage of 0.07 V,crest factor of 1.01,and ripple coefficient of 2.2%.The TENG provides a feasible method to generate stable electric energy and to supply power to low-consumption electronic devices.

A multi-mode low ripple charge pump with active regulation

In order to improve efficiency and reduce the output ripple, a novel multi-mode charge pump is presented. The proposed charge pump includes dual-loop regulation topology-skip and linear modes. It consumes low quiescent current in skip mode for light loads, and produces low ripple in linear mode for heavy loads, which closes the gap between linear mode and skip mode with active regulation; a multi-mode charge pump employing the technique has been implemented in the UMC 0.6-μm-BCD process. The results indicate that the charge pump works well and effectively; it has low ripple with special regulation, and minimizes the size of the capacitance, then decreases the area of the PCB board. The adjustable output of the positive charge pump is 10-30 V, and the maximum output ripple is 100 mV when the load current is 200 mA. The line regulation is 0.2%/V, and load regulation is 0.075%.

A novel low ripple charge pump with a 2X/1.5X booster for PCM

A low ripple switched capacitor charge pump applicable to phase change memory （PCM） is presented. For high power efficiency, the selected charge pump topology can automatically change the power conversion ratio between 2X/1.5X modes with the input voltage. For a low output ripple, a novel operation mode is used. Compared with the conventional switched capacitor charge pump, the flying capacitor of the proposed charge pump is charged to Vo- 14n during the charge phase （Vo is the prospective output voltage）. In the discharge phase, the flying capacitor is placed in series with the Vin to transfer energy to the output, so the output voltage is regulated at Vo. A simulation was implemented for a DC input range of 1.6-2.1 V in on SMIC standard 40 nm CMOS process, the result shows that the new operation mode could regulate the output of about 2.5 V with a load condition from 0 to 10 mA, and the ripple voltage is lower than 4 mV. The maximum power efficiency reaches 91%.

Airgap-harmonic-oriented Partitioned Design Method of PMV Motor with Improved Torque Performances

Here,we introduce a partitioned design method that is oriented toward airgap harmonic for permanent magnet vernier(PMV)motors.The method proposes the utilization of airgap flux harmonics as an effective bridge between the torque design region and the torque performances.To illustrate the efficacy of this method,a partitioned design PMV motor is presented and compared with the initial design.Firstly,the torque design region of the rotor is artfully divided into the torque enhancement region and ripple reduction region.Meanwhile,the main harmonics that generate output torque are chosen and enhanced,optimization.Moreover,the harmonics that generate torque ripple are selected and reduced based on torque harmonics optimization.Finally,the functions of the partitioned PMV motor torque are assessed based on the finite element method.By the purposeful design of these two regions,the output torque is strengthened while torque ripple is inhibited effectively,verifying the effectiveness and reasonability of the proposed design method.

Single Phase Induction Motor Drive with Restrained Speed and Torque Ripples Using Neural Network Predictive Controller

In industrial drives, electric motors are extensively utilized to impart motion control and induction motors are the most familiar drive at present due to its extensive performance characteristic similar with that of DC drives. Precise control of drives is the main attribute in industries to optimize the performance and to increase its production rate. In motion control, the major considerations are the torque and speed ripples. Design of controllers has become increasingly complex to such systems for better management of energy and raw materials to attain optimal performance. Meager parameter appraisal results are unsuitable, leading to unstable operation. The rapid intensification of digital computer revolutionizes to practice precise control and allows implementation of advanced control strategy to extremely multifaceted systems. To solve complex control problems, model predictive control is an authoritative scheme, which exploits an explicit model of the process to be controlled. This paper presents a predictive control strategy by a neural network predictive controller based single phase induction motor drive to minimize the speed and torque ripples. The proposed method exhibits better performance than the conventional controller and validity of the proposed method is verified by the simulation results using MATLAB software.

Design of an Asymmetric Rotor Pole for Wound Field Synchronous Machines

This study proposes a novel asymmetric rotor pole design for wound field synchronous machines(WFSMs),which can achieve high saliency ratio and also low torque ripple.The key point is the optimal design of the asymmetric rotor pole with the inverse-cosine-shaped(ICS)plus reverse 3rd harmonic shaping.The asymmetric rotor pole can help to improve the average output torque by enhancing the saliency ratio.The reverse 3rd harmonic shaping on the rotor pole surface is mainly used to reduce the torque ripple.To certify the effectivity of the proposed design,three-phase 54-slot/6-pole 4.7kW WFSMs with uniform air gap and with non-uniform air gap shaped by the ICS plus optimum reverse 3rd harmonic are utilized as the basic model and referenced model for comparison.For the referenced model,the optimum amplitude of reverse 3rd harmonic is preferred as 1/6.Finally,all electromagnetic characteristics of the investigated machines are predicted by the finite-element method(FEM).The highest saliency ratio and comparatively low torque ripple have been verified.

Fast corrector power supply design for HEPS

Background High-energy photon source under construction is a fourth-generation synchrotronradiation light source with energy of 6 Gev and ultra-low emittance(lower than 0.1 nm rad).The ultra-low beam emittance requires high beam stability.Purpose In order to meet this requirement of low beam emittance,the fast close orbit correctionsystem is used to keep beam on the right orbit.The fast close orbit correction system need fast corrector power supply to drive the calibration magnet to complete track correction.So,a fastcorrector power supply prototype with high bandwidth and low current ripple to improve the performance of the fast close orbit correction system to prove the high beam stability had beendeveloped.Methods The prototype use a novel multilevel switch-mode structure to provide the dynamicrequirement.The prototype adopts FPGA for full-digital control and use high-speed ADC with temperature control.By using a precision sampling circuit(ADC+DCCT),the prototypeoutputs current ripple can meet the requirement.Results and conclusion The designed for HEPS meet the design requirement.Through test,the prototype has asmall signal bandwidth of 10 kHz and output current ripple lower than 20 ppm.