Estimating the Input Power of a Power Plant Using the Efficiency of the Inverter

The study focuses on estimating the input power of a power plant from available data, using the theoretical inverter efficiency as the key parameter. The paper addresses the problem of missing data in power generation systems and proposes an approach based on the efficiency formula widely documented in the literature. In the absence of input data, this method makes it possible to estimate the plant’s input power using data extracted from the site, in particular that provided by the Ministry of the Environment. The importance of this study lies in the need to accurately determine the input power in order to assess the overall performance of the energy system.

Cotidal charts and tidal power input atlases of the global ocean from TOPEX/Poseidon and JASON-1 altimetry

The global distributions of eight principal tidal constituents, M2, S2, K1, O1, N2, K2, P1, and Q1, are derived using TOPEX/Poseidon and JASON-1（T/P-J） satellite altimeter data for 16 a. The intercomparison of the derived harmonics at 7000 subsatellite track crossover points shows that the root mean square （RMS） values of the tidal height differences of the above eight constituents range from 1.19 cm to 2.67 cm, with an average of about 2 cm. The RMS values of the tidal height differences between T/P-J solutions and the harmonics from ground measurements at 152 tidal gauge stations for the above constituents range from 0.34 cm to 1.08 cm, and the relative deviations range from 0.031 to 0.211. The root sum square of the RMS differences of these eight constituents is 2.12 cm, showing the improvement of the present model over the existing global ocean tidal models. Based on the obtained tidal model the global ocean tidal energetics is studied and the global distribution of the tidal power input density by tide-generating force of each constituent is calculated, showing that the power input source regions of semidiurnal tides are mainly concentrated in the tropical belt between 30S and 30N, while the power input source regions of diurnal tides are mainly concentrated off the tropic oceans. The global energy dissipation rates of the M2, S2, K1, O1, N2, P1, K2 and Q1 tides are 2.424, 0.401, 0.334, 0.160, 0.113, 0.035, 0.030 and 0.006 TW, respectively. The total global tidal dissipation rate of these eight constituents amounts to 3.5 TW.

Effects of low temperatures on strength and power input into rock failure

Study results of low temperature effects on the strength index and specific power input into rock failure are presented.It has been experimentally determined that within the range of-5 °С to-15 °С,there is a local minimum at which the compression strength and specific power input into failure of some rocks are 10%-50% lower than those at positive temperatures.

A Novel Method of Auxiliary Power Supply Used in Wide-Range High Voltage Input DC-DC Converter

In high voltage input DC-DC converter, auxiliary winding of isolation transformer is usually used to supply power for control circuit. Due to the wide-range of input voltage, the variable output voltage of auxiliary winding will cause a series of problems, such as variable drive pulse amplitude, increased driver switching devices loss and drive transformer core saturation. This paper analyzes the influence of variable output voltage of auxiliary winding in detail. A novel method is proposed to solve the problem of large variation range of auxiliary winding output voltage, which is adding a buck converter between the auxiliary winding and the control circuit. A dual switch forward convert has been designed with 300 V - 800 V input and 24 V/5 A output. The results show that this method is effective by comparing the different results of using buck converter or not.

Research on Input Power Testing Technology of Smart Toilet

Input power is an important indicator for the safety testing of electrical and electronic products.Smart toilets have been frequently detected that the actual input power is inconsistent with the nominal power.Research and analysis show that the accuracy of the input power measurement results of the smart toilet mainly depends on the temperature control principle and power test method of the product.This article mainly discusses the characteristics of product temperature control,the testing method of mean and peak power and its characteristics,which will provide reference for the input power test of the smart toilet,and will improve the accuracy of power measurement.

An Efficient MMI SOI Splitter with Multimode Input/Output Waveguides

A 1×8 multimode interference power splitter with multimode input/output waveguides in SOI material is designed by the beam propagation method and fabricated by the inductive coupled plasma etching technology for use in fiber optics communication systems.The fabricated device exhibits low loss and good coupling uniformity.The excess loss is lower than 0 8dB,and the uniformity is 0 45dB at the wavelength of 1550nm.Moreover,the polarization dependent loss is lower than 0 7dB at 1550nm.The device size is only 2mm×10mm.

Channel Capacity and Power Allocation of MIMO Visible Light Communication System

In this paper,the channel capacity of the multiple-input multiple-output(MIMO)visible light communication(VLC)system is investigated under the peak,average optical and electrical power constraints.Finding the channel capacity of MIMO VLC is shown to be a mixed integer programming problem.To address this open problem,we propose an inexact gradient projection method to find the channel capacity-achieving discrete input distribution and the channel capacity of MIMO VLC.Also we derive both upper and lower bounds of the capacity of MIMO VLC with the closed-form expressions.Furthermore,by considering practical discrete constellation inputs,we develop the optimal power allocation scheme to maximize transmission rate of MIMO VLC system.Simulation results show that more discrete points are needed to achieve the channel capacity as SNR increases.Both the upper and lower bounds of channel capacity are tight at low SNR region.In addition,comparing the equal power allocation,the proposed power allocation scheme can significantly increase the rate for the low-order modulation inputs.

Ultrasonic power features of wire bonding and thermosonic flip chip bonding in microelectronics packaging

The driving voltage and current signals of piezoceramic transducer (PZT) were measured directly by designing circuits from ultrasonic generator and using a data acquisition software system. The input impedance and power of PZT were investigated by using root mean square (RMS) calculation. The vibration driven by high frequency was tested by laser Doppler vibrometer (PSV-400-M2). And the thermosonic bonding features were observed by scanning electron microscope (JSM-6360LV). The results show that the input power of bonding is lower than that of no load. The input impedance of bonding is greater than that of no load. Nonlinear phase, plastic flow and expansion period, and strengthening bonding process are shown in the impedance and power curves. The ultrasonic power is in direct proportion to the vibration displacement driven by the power, and greater displacements driven by high power (>5 W) result in welding failure phenomena, such as crack, break, and peeling off in wedge bonding. For thermosonic flip chip bonding, the high power decreases position precision of bonding or results in slippage and rotation phenomena of bumps. To improve reliability and precision of thermosonic bonding, the low ultrasonic power (about 1-5 W) should be chosen.

Design and Analysis of Low Power Hybrid Memristor-CMOS Based Distinct Binary Logic Nonvolatile SRAM Cell

Memristor is a newly found fourth circuit element for the next generation emerging nonvolatile memory technology. In this paper, design of new type of nonvolatile static random access memory cell is proposed by using a combination of memristor and complemented metal oxide semiconductor. Biolek memristor model and CMOS 180 nm technology are used to form a single cell. By introducing distinct binary logic to avoid safety margin is left for each binary logic output and enables better read/write data integrity. The total power consumption reduces from 0.407 mw (milli-watt) to 0.127 mw which is less than existing memristor based memory cell of the same CMOS technology. Read and write time is also significantly reduced. However, write time is higher than conventional 6T SRAM cell and can be reduced by increasing motion of electron in the memristor. The change of the memristor state is shown by applying piecewise linear input voltage.

Similarities of Some Wind Input and Dissipation Source Terms

Wind input parameterizations proposed by Jeffreys, Sverdrup and Munk, and Plant are analyzed. It is found by analogy that the similarity of integrals of the three wind input parameterizations exists. Wave breaking dissipation parameterizations proposed by Tsikunov, Hasselmann, and Phillips are also analyzed. Likewise it is found by analogy that the similarity of integrals of the three dissipation parameterizations exists. The similarities of wind input and dissipation are applied to the investigation of the fetch-limited growth of wind waves, together with the 3/2 power law presented by Toba. Some semi-empirical formulas concerning the growth of wave height and period with fetch are presented. The results from the formulas are in good agreement with previous field observations.

Design of Power Amplifier for mm Wave 5G and Beyond

With targets of cost reduction per bit and high energy efficiency,5G and beyond call for innovation in the mmWave transmitter architecture and the power amplifier(PA)circuit.To illustrate these points,this paper firstly explains the benefits and design implications of the hybrid beamforming structure in terms of the mmWave spectrum characteristics,energy efficiency,data rate,communication capacity,coverage and implementation technology choices.Then after reviewing the techniques to improve the power amplifier(PA)output power and efficiency,the design considerations and test results of 60 GHz and 90 GHz mmWave PAs in bulk complementary metal oxide semiconductor(CMOS)process are shown.

A Novel Polymorphic Topology with Hybrid Control Strategy Based LLC Resonant Converter for Ultra-Wide Input Voltage Range Applications

To realize effective utilization of renewable energy sources,a novel polymorphic topology with hybrid control strategy based LLC resonant converter was analyzed and designed in this paper.By combining the merits of a full bridge LLC resonant converter,three-level half bridge LLC resonant converter,and variable frequency control mode,the converter realizes an intelligent estimation of input voltage by automatically changing its internal cir-cuit topology.Under this control strategy,different input voltages determine different operation modes.This is achieved in full bridge LLC mode when the input voltage is low.If the input voltage rises to a certain level,it operates in three-level half bridge LLC mode.These switches are digital and entirely carried out by the DSP(Digi-tal Signal Processor),which means that an auxiliary circuit is unnecessary,where a simple strategy of software modification can be utilized.Experimental results of a 500W prototype with 100V~600V input voltage and full load efficiency of up to 92%are developed to verify feasibility and practicability.This type of converter is suitable for applications with an ultra-wide input voltage range,such as wind turbines,photovoltaic generators,bioenergy,and other renewable energy sources.

A Multi Input Multi Output Converter for Hybrid Energy Systems

Multi input and multi output converters are becoming popular because they are cost effective and compact. This paper proposes a multi input multi output converter for Grid-Solar power integration for uninterrupted power supply. The proposed converter uses four winding transformer with two primary windings and two secondary windings. The grid supply is connected to the first winding of transformer through rectifier-inverter for controlled power transfer. The solar energy is inverted and applied to the second winding of primary. Two output ports are considered. The circuit is designed to get zero current switching during turn-off and zero voltage switching during turn-on to alleviate the switching losses. The simulation results for the proposed configuration are presented in this paper.

基于热功率的焊接热输入分配及稀释率预测

【目的】热输入Q_(HI)仅简单描述了焊接能量的来源与大小,没有阐明焊缝与母材吸收的热量如何分配的不足。【方法】该文利用基于填充金属量提出的热功率PPR概念,通过焊缝尺寸测量,JmatPro与公式计算等手段,实现了焊接热输入分配及稀释率进行的预测。【结果】基于P_(PR)可实现对熔化母材面积A_(mb)的预测,其曲线变化可分为渐增区、快增区、缓增区3个阶段。结合JmatPro计算的材料体积比热容与A_(mb)预测公式,可将不同PPR下的有效焊接热输入Q_(e)进行细分,发现在可焊区形成焊缝的热输入只占其31.77%~34.69%。【结论】提出了基于P_(PR)的焊缝面积百分比稀释率δ预测公式,并给出可焊区的焊接热功率为12.69~47.88 kW/cm^(2),稀释率为48.28%~85.03%。

OPTIMAL POWER ALLOCATION WITH AF AND SDF STRATEGIES IN DUAL-HOP COOPERATIVE MIMO NETWORKS

Dual-hop cooperative Multiple-Input Multiple-Output (MIMO) network with multi-relay cooperative communication is introduced. Power allocation problem with Amplify-and-Forward (AF) and Selective Decode-and-Forward (SDF) strategies in multi-node scenario are formulated and solved respectively. Optimal power allocation schemes that maximize system capacity with AF strategy are presented. In addition, optimal power allocation methods that minimize asymptotic Symbol Error Rate (SER) with SDF cooperative protocol in multi-node scenario are also proposed. Furthermore, performance comparisons are provided in terms of system capacity and approximate SER. Numerical and simulation results confirm our theoretical analysis. It is revealed that, maximum system capacity could be obtained when powers are allocated optimally with AF protocol, while minimization of system's SER could also be achieved with optimum power allocation in SDF strategy. In multi-node scenario, those optimal power allocation algorithms are superior to conventional equal power allocation schemes.

基于DDPG的智能反射面辅助无线携能通信系统性能优化

针对智能反射面(IRS, intelligent reflecting surface)辅助的多输入单输出(MISO, multiple input singleoutput)无线携能通信(SWIPT, simultaneous wireless information and power transfer)系统,考虑基站最大发射功率、IRS反射相移矩阵的单位膜约束和能量接收器的最小能量约束,以最大化信息传输速率为目标,联合优化了基站处的波束成形向量和智能反射面的反射波束成形向量。为解决非凸优化问题,提出了一种基于深度强化学习的深度确定性策略梯度(DDPG, deep deterministic policy gradient)算法。仿真结果表明,DDPG算法的平均奖励与学习率有关,在选取合适的学习率的条件下,DDPG算法能获得与传统优化算法相近的平均互信息,但运行时间明显低于传统的非凸优化算法,即使增加天线数和反射单元数,DDPG算法依然可以在较短的时间内收敛。这说明DDPG算法能有效地提高计算效率,更适合实时性要求较高的通信业务。

一种可拓展双输入高增益DC/DC变换器

针对光伏发电系统中光伏电池板集成汇流的需求,提出了一种可拓展双输入高增益DC/DC变换器。该变换器采用了一种新型拓扑结构,可在实现输入输出电压高增益变换的同时降低了开关器件的电压应力。此外,所提变换器还具有可拓展性,可以根据不同的光伏电池板数量和输出电压要求对端口进行扩展,从而降低系统的复杂性和成本。首先详细介绍了所提变换器的拓扑结构,并推导出变换器在不同工作模态下的运行原理。然后,对该变换器的增益特性、开关器件的电压和电流应力、关键器件的参数选择和损耗计算等方面进行了深入的理论分析。最后,搭建了一台输出功率为1 kW的实验样机,并进行了实验测试。实验结果验证了所提变换器理论分析的正确性和可行性。

基于VMD的MAG焊输入端电信号频域分析

通过电信号采集平台,对焊机输入输出端电信号进行同步采集.分析弧焊电源整流电路,对输入电信号进行整流处理得到输入电压与电流,最终计算得到弧焊电源的输入功率.经过对比发现输出电流与瞬时输入功率峰值变化趋势基本一致.论述了变分模态分解(VMD)原理及方法,并对瞬时输入功率进行分解,得到一系列特征BLIMFs信号.通过对不同过渡模式(大滴过渡、短路过渡和混合过渡)下瞬时输入功率信号、特征IMF信号和焊接输出电流信号在频域上的对比分析,发现VMD能够有效得到低频(IMF1)、中频(IMF2)和高频信号(IMF3),且中频和高频信号表现出了焊机不控整流的脉动信息(300 Hz)以及电网的干扰.而低频IMF1信号与焊接输出电流信号频域一致性良好,并在时域上也有良好的一致性.结果表明了通过对输入瞬时功率的VMD,其低频分量能够有效表征焊接过程,从而为从输入端评定过渡过程稳定性提供了一种新思路.

基于多模式分解和多分支输入的光伏功率超短期预测

针对光伏发电功率随机性强、波动性大导致其预测精度不高的问题,提出一种基于自适应近邻传播聚类(adaptive affinity propagation clustering,adAP)、多模式分解、多分支输入组合的光伏功率预测方法。首先,基于相关性分析找到与光伏发电功率高度相关的气象因素,并利用快速傅里叶变换(fast Fourier transform,FFT)将光伏输出功率从时域转换到频域,与相关度高的气象因素一起作为adAP算法的聚类特征,对具有相似气象特征的日场景进行分类;其次,对聚类相似日较少且输出功率波动剧烈天气类型中的气象相关因素和光伏输出功率添加高斯白噪声,并将其与原始数据合并,达到倍增样本的效果,以提升模型的泛化能力和鲁棒性;然后,使用变分模态分解(variational mode decomposition,VMD)、奇异谱分解(singular spectrum decomposition,SSD)和群分解(swarm decomposition,SWD)对光伏功率、辐照度和温度进行分解,削弱原始序列的波动性,丰富模型的输入特征;最后,搭建多分支的残差网络(residual network,ResNet)和长短期记忆网络(long short term memory network,LSTM)模型,提取数据的时间特征和波动特征,合并后输入到门控循环单元网络(gated recurrent unit network,GRU)中,建立历史特征和未来光伏输出功率的联系,得到预测结果。实验结果表明,所提出的多模型组合预测方法在光伏功率波动较缓天气情况下,能够保持较高的预测精度;在波动剧烈天气情况下,能够较大地提升预测精度。

毫米波非正交多址接入的节能资源分配

用户干扰会降低毫米波大规模多输入多输出非正交多址接入(mMIMO-NOMA)系统的能量效率,解决该问题需要采用合理的资源分配方案。基于已知的信道状态信息建立从基站到用户的系统模型,在考虑基站的发射功率和服务质量情况下,提出具有多个约束条件的能效优化问题。该问题受用户分组、预编码、功率分配等多种因素的影响,是一个复杂的非凸问题。首先在假设功率固定的情况下,提出一种用户分组算法对需要提供服务的用户进行匹配分组,在此基础上,最大化全连接架构增益设计模拟预编码,采用迫零法设计数字预编码。其次将能效最大化问题转化为一系列子问题,并采用惩罚函数进行处理。最后设计基于Dinkelbach的迭代算法用于功率分配,根据能效公式计算出能量效率。MATLAB仿真分析结果表明,该方案能够保证用户间公平性,且在能量效率方面优于现有方案。当信噪比为15 dB时,全连接架构的能量效率提升约25.5%,子链接架构的能量效率提升约25.1%。