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Cyclic moving average control approach to cylinder pressure and its experimental validation

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控制理论与应用（英文版） 2009年第4期7卷 345-351页

作者： Po LI Tielong SHEN Junichi KAKO kaipei liu School of electrical engineering Wuhan Unversity Wuhan Hubei 430072 China Department of Mechanical Engineering Sophia University Tokyo 102-8554 Japan Higashifuji Technical Center Toyota Motor Corporation Shizuoka 410-1193 Japan

Cyclic variability is a factor adversely affecting engine performance. In this paper a cyclic moving average regulation approach to cylinder pressure at top dead center （TDC） is proposed, where the ignition time is adopted as the control input. The dynamics from ignition time to the moving average index is described by ARMA model. With this model, a one-step ahead prediction-based minimum variance controller （MVC） is developed for regulation. The performance of the proposed controller is illustrated by experiments with a commercial car engine and experimental results show that the controller has a reliable effect on index regulation when the engine works under different fuel injection strategies, load changing and throttle opening disturbance.

关键词： In-cylinder pressure balancing Cyclic moving average modeling ARMA model MVC

Improved edge lightweight YOLOv4 and its application in on-site power system work

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Global Energy Interconnection 2022年第2期5卷 168-180页

作者： Kexin Li Liang Qin Qiang Li Feng Zhao Zhongping Xu kaipei liu School of Electrical Engineering and Automation Wuhan UniverstiyWuhan430072P.R.China State Grid Information&Telecommunication Group Co. LtdBeijing102211P.R.China Beijing State Grid Information&Telecommunication Accenture Information Technology Co. Ltd.Beijing 100052P.R.China

A“cloud-edge-end”collaborative system architecture is adopted for real-time security management of power system on-site work,and mobile edge computing equipment utilizes lightweight intelligent recognition algorithms for on-site risk assessment and *** to its lightweight and fast speed,YOLOv4-Tiny is often deployed on edge computing equipment for real-time video stream detection;however,its accuracy is relatively *** study proposes an improved YOLOv4-Tiny algorithm based on attention mechanism and optimized training methods,achieving higher accuracy without compromising the ***,a convolution block attention module branch is added to the backbone network to enhance the feature extraction capability and an efficient channel attention mechanism is added in the neck network to improve feature ***,three optimized training methods:transfer learning,mosaic data augmentation,and label smoothing are used to improve the training effect of this improved ***,an edge computing equipment experimental platform equipped with an NVIDIA Jetson Xavier NX chip is established and the newly developed algorithm is tested on *** to the results,the speed of the improved YOLOv4-Tiny algorithm in detecting on-site dress code compliance datasets is 17.25 FPS,and the mean average precision(mAP)is increased from 70.89%to 85.03%.

关键词： On-site power system work YOLOv4-Tiny Convolution block attention mechanism Efficient channel attention Optimized training methods.

Harmonic analysis based on time domain mutual-multiplication window

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Journal of Modern Power Systems and Clean Energy 2016年第1期4卷 47-53页

作者： Tianyuan TAN Wenjuan CHEN kaipei liu Niu XIONG Junmin ZHANG Junhua WANG School of Electrical Engineering Wuhan UniversityWuhan 430072China School of Computer Science South-Central University for NationalitiesWuhan 430072China

The signal spectral leakage and fence effect are prone to take place during the power harmonic analysis by fast fourier transform(FFT) under asynchronous *** inhibiting ability of classical window functions is restricted by side-lobe behaviors. A new type window function called time domain mutual-multiplication window, is obtained by multiplication operation of several window functions. A novel approach of harmonic analysis is developed through analyzing performances of main-lobe and side-lobe of the new window. Simulation results show that the time domain mutual-multiplication window can significantly suppress frequency spectral leakage and improve the accuracy of harmonic parameter estimation.

关键词： Mutual-multiplication window Fast Fourier Transform Harmonic Analysis Main-lobe Side-lobe

Study on the ratio change measurement of 1000 kV HVDC divider based on improved DC voltage summation method

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High Voltage 2020年第2期5卷 202-208页

作者： Dengyun Li kaipei liu Min Lei Feng Zhou Changxi Yue Jicheng Yu School of Electrical Engineering Wuhan UniversitySchool of Electrical EngineeringWuhan 430072People's Republic of China China Electric Power Research Institute Wuhan 430074People's Republic of China

Determining the voltage ratio change is one of the core issues in the traceability of the DC voltage *** on the previous research results,this study proposes an improved DC voltage summation method to evaluate the voltage division ratio error of 1000 kV DC resistance *** principle of the method is to calibrate the voltage divider with rated voltage 2U by using two auxiliary voltage dividers which are with rated voltage U,wherein the high-voltage(HV)arm and the low-voltage arm of the auxiliary voltage divider can be *** results show that compared with the conventional method,the method can reduce one measurement variable when determining the divider's ratio change,thus simplifying the calibration *** voltage ratio of 100 kV measured by the method of this study was well-verified by the calibration results from the National Institute of Metrology(NIM,China)and Physikalisch-Technische Bundesanstalt(PTB,Germany).Using the proposed method,the ratio change of DC voltage divider at an applied voltage of 1000 kV was effectively obtained and the uncertainty of 2.5μV/V was *** results can provide technical guarantee for the accurate measurement of HVDC magnitude.

关键词： divider ratio method

Adaptive VSG control of flywheel energy storage array for frequency support in microgrids

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Global Energy Interconnection 2024年第5期7卷 563-576页

作者： Penghui Ren Jingwen Zheng Liang Qin Ruyin Sun Shiqi Yang Jiangjun Ruan kaipei liu Tinghui Ouyang Hubei Key Laboratory of Power Equipment&System Security for Integrated Energy Wuhan 430072P.R.China School of Electrical Engineering and Automation Wuhan UniversityWuhan 430072P.R.China Electric Power Research Institute State Grid Hubei Electric Power Co.Ltd.Wuhan 430077P.R.China Center for Computational Sciences University of Tsukuba(UT)Ibaraki 305-8577Japan

The application of virtual synchronous generator(VSG)control in flywheel energy storage systems(FESS)is an effective solution for addressing the challenges related to reduced inertia and inadequate power supply in *** the significant variations among individual units within a flywheel array and the poor frequency regulation performance under conventional control approaches,this paper proposes an adaptive VSG control strategy for a flywheel energy storage array(FESA).First,by leveraging the FESA model,a variable acceleration factor is integrated into the speed-balance control strategy to effectively achieve better state of charge(SOC)equalization across ***,energy control with a dead zone is introduced to prevent SOC of the FESA from exceeding the *** dead zone parameter is designed based on the SOC warning intervals of the flywheel array to mitigate its impact on regular *** addition,VSG technology is applied for the grid-connected control of the FESA,and the damping characteristic of the VSG is decoupled from the primary frequency regulation through power differential *** ensures optimal dynamic performance while reducing the need for frequent involvement in frequency ***,a parameter design method is developed through a small-signal stability ***,considering the SOC of the FESA,an adaptive control strategy for the inertia damping and the P/ωdroop coefficient of the VSG control is proposed to optimize the grid support services of the ***,the effectiveness of the proposed control methods is demonstrated through electromagnetic transient simulations using MATLAB/Simulink.

关键词： Flywheel array control Virtual Synchronous Generator Microgrid Frequency regulation Adaptive control

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电能计量误差分析与电能计费问题的讨论

电工技术学报 2005年第2期20卷 63-68页

作者：周莉刘开培武汉大学电气工程学院武汉430074

在电力市场化的条件下如何计算谐波电能和暂态电能,谐波电能和暂态电能损耗由谁承担,以及这部分损耗采取何种计费标准,都是亟待解决的问题。本文首先分析了瞬时功率的构成,得到有功功率的公式,接着探讨了前置滤波器对电能计量的影响、... 详细信息

在电力市场化的条件下如何计算谐波电能和暂态电能,谐波电能和暂态电能损耗由谁承担,以及这部分损耗采取何种计费标准,都是亟待解决的问题。本文首先分析了瞬时功率的构成,得到有功功率的公式,接着探讨了前置滤波器对电能计量的影响、暂态情况下的电能计量问题和用户类型对电能转换的影响,最后对有功计费提出了一些建议。

关键词：谐波暂态电能有功滤波器

基于Walsh变换的PWM优化脉冲调制方法

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电工技术学报 2007年第4期22卷 118-123页

作者：秦亮刘开培张慧武汉大学电气工程学院武汉430072

选择性谐波消除技术在计算开关角时涉及到非线性超越方程的求解,需要对开关角赋初值进行离线迭代计算,很难保证初值求解一定收敛,而且选择性谐波消除技术只能控制谐波幅值,不能控制相位。基于上述原因,提出基于Walsh变换的计算方法,得... 详细信息

选择性谐波消除技术在计算开关角时涉及到非线性超越方程的求解,需要对开关角赋初值进行离线迭代计算,很难保证初值求解一定收敛,而且选择性谐波消除技术只能控制谐波幅值,不能控制相位。基于上述原因,提出基于Walsh变换的计算方法,得到求解开关角的线性表达式,不需要对开关角赋初值,简单的线性计算就可以得到开关角的值,并且可以同时达到对谐波幅值控制和相位的控制,最后通过算例证明了该方法的正确性。

关键词：脉冲宽度调制 Walsh变换选择性谐波消除法

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C型滤波器在混合型有源滤波器中应用及优化

电力自动化设备 2009年第2期29卷 39-43页

作者：陶骞刘开培湖北省电力试验研究院湖北武汉430077 武汉大学电气工程学院湖北武汉430072

为了在减小有源电力滤波器设计容量、降低成本的同时确保其谐波补偿性能,将C型无源滤波器代替通常的单调谐无源环节与有源滤波器串联,利用其在基波频率时表现出高阻抗,而在谐波频率时表现为低阻抗来承栽大部分基波电压,从而可有效地减... 详细信息

为了在减小有源电力滤波器设计容量、降低成本的同时确保其谐波补偿性能,将C型无源滤波器代替通常的单调谐无源环节与有源滤波器串联,利用其在基波频率时表现出高阻抗,而在谐波频率时表现为低阻抗来承栽大部分基波电压,从而可有效地减小有源滤波器的设计容量。通过分析C型滤波器的阻抗频率特性方程,给出了C型滤波器的参数算法及优化过程。仿真及试验结果表明C型滤波器在低于截止频率时表现为电容特性,而在高频段表现出纯电阻特性,90%的电压由C型滤波器承担,系统的总谐波含量THD低于5%,5次和7次谐波基本消除。

关键词：混合有源滤波器 C型滤波器基波频率谐波频率阻抗频率特性优化

Research on Optimal Transformer Maintenance Scheme Based on LS-SVM

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中国电机工程学报 2012年第22期32卷 I0013-I0013页

作者： liu Jian liu kaipei ZHOU Shijie GUO Wei Wuhan University