随着可再生能源接入电网比例的逐步增大,热力发电厂需要应对更加频繁、更大范围的负荷变化,给电厂的高阶大惯性过热汽温过程的控制带来严峻的挑战。为此,文中针对一类高阶大惯性过热汽温过程,提出一种基于相位补偿的自抗扰控制(phase co...随着可再生能源接入电网比例的逐步增大,热力发电厂需要应对更加频繁、更大范围的负荷变化,给电厂的高阶大惯性过热汽温过程的控制带来严峻的挑战。为此,文中针对一类高阶大惯性过热汽温过程,提出一种基于相位补偿的自抗扰控制(phase compensation based active disturbance rejection control,PC-ADRC)方法。首先,阐述过热汽温系统的工作原理和控制难点。然后,采用低频近似法详细推导相位补偿(phase compensation,PC)网络模型,提出采用PC网络对模型动态特性进行补偿,得到等效降阶模型的简化思路。为便于工程应用,给出PC-ADRC系统的简单实现方法和等效模型分析。最后,对PC-ADRC系统的稳定性和鲁棒性进行研究。理论分析和仿真结果表明,所提出的PC-ADRC系统能有效提升高阶过程控制系统的鲁棒性和快速响应能力。展开更多
Recognition and correction of ionospheric phase path contamination is a vital part of the global radar signal processing sequence. A number of model-based correction algorithms have been developed to deal with the rad...Recognition and correction of ionospheric phase path contamination is a vital part of the global radar signal processing sequence. A number of model-based correction algorithms have been developed to deal with the radar performance degradation due to the ionospheric distortion and contamination. This paper addresses a novel parametric estimation and compensation method based on High-order Ambiguity Function (HAF) to solve the problem of phase path contamination of HF skywave radar signals. When signal-to-noise ratio and data sequence available satisfy the predefined conditions, the ionospheric phase path contamination may be modeled by a polynomial phase signal (PPS). As a new parametric tool for analyzing the PPS, HAF is introduced to estimate parameters of the polynomial-phase model and reconstruct the correction signal. Using the reconstructed correction signal, compensation can be performed before coherent integration so that the original echo spectrum can be restored. A piecewise scheme is proposed to track rapid variation of the phase contamination based on HAF method, and it can remove the Doppler spread effect caused by the ionosphere nonstationarity. Simulation and experimental results are given to demonstrate the efficiency of the proposed algorithm.展开更多
电力系统的瞬时性故障易产生暂态衰减直流分量DDC(decaying DC component)、高次谐波等干扰信号,有效滤除干扰信号以实现电压基波幅值相位的快速、准确检测,对于提升电能质量非常重要。为此,基于三相畸变电压信号的周期性和半波对称性,...电力系统的瞬时性故障易产生暂态衰减直流分量DDC(decaying DC component)、高次谐波等干扰信号,有效滤除干扰信号以实现电压基波幅值相位的快速、准确检测,对于提升电能质量非常重要。为此,基于三相畸变电压信号的周期性和半波对称性,提出在abc坐标系下对畸变电压分别延迟半周期、全周期采样,实现DDC分量的单位周期检测。其次,针对同时含有DDC与高次谐波的畸变信号,在dq旋转坐标系下将DDC检测算法与滑动平均滤波算法结合,实现单位周期同时滤除DDC与高次谐波分量。最后,将所提检测算法与电压相位开环算法结合,通过搭建RT-LAB半实物实时仿真平台对基波电压幅值相位进行检测验证。实验结果表明:在dq坐标系下同时滤除DDC与高次谐波干扰信号的检测算法响应时间仅为20 ms,验证了所提算法的有效性以及分析结论的正确性。展开更多
文摘随着可再生能源接入电网比例的逐步增大,热力发电厂需要应对更加频繁、更大范围的负荷变化,给电厂的高阶大惯性过热汽温过程的控制带来严峻的挑战。为此,文中针对一类高阶大惯性过热汽温过程,提出一种基于相位补偿的自抗扰控制(phase compensation based active disturbance rejection control,PC-ADRC)方法。首先,阐述过热汽温系统的工作原理和控制难点。然后,采用低频近似法详细推导相位补偿(phase compensation,PC)网络模型,提出采用PC网络对模型动态特性进行补偿,得到等效降阶模型的简化思路。为便于工程应用,给出PC-ADRC系统的简单实现方法和等效模型分析。最后,对PC-ADRC系统的稳定性和鲁棒性进行研究。理论分析和仿真结果表明,所提出的PC-ADRC系统能有效提升高阶过程控制系统的鲁棒性和快速响应能力。
文摘Recognition and correction of ionospheric phase path contamination is a vital part of the global radar signal processing sequence. A number of model-based correction algorithms have been developed to deal with the radar performance degradation due to the ionospheric distortion and contamination. This paper addresses a novel parametric estimation and compensation method based on High-order Ambiguity Function (HAF) to solve the problem of phase path contamination of HF skywave radar signals. When signal-to-noise ratio and data sequence available satisfy the predefined conditions, the ionospheric phase path contamination may be modeled by a polynomial phase signal (PPS). As a new parametric tool for analyzing the PPS, HAF is introduced to estimate parameters of the polynomial-phase model and reconstruct the correction signal. Using the reconstructed correction signal, compensation can be performed before coherent integration so that the original echo spectrum can be restored. A piecewise scheme is proposed to track rapid variation of the phase contamination based on HAF method, and it can remove the Doppler spread effect caused by the ionosphere nonstationarity. Simulation and experimental results are given to demonstrate the efficiency of the proposed algorithm.
文摘电力系统的瞬时性故障易产生暂态衰减直流分量DDC(decaying DC component)、高次谐波等干扰信号,有效滤除干扰信号以实现电压基波幅值相位的快速、准确检测,对于提升电能质量非常重要。为此,基于三相畸变电压信号的周期性和半波对称性,提出在abc坐标系下对畸变电压分别延迟半周期、全周期采样,实现DDC分量的单位周期检测。其次,针对同时含有DDC与高次谐波的畸变信号,在dq旋转坐标系下将DDC检测算法与滑动平均滤波算法结合,实现单位周期同时滤除DDC与高次谐波分量。最后,将所提检测算法与电压相位开环算法结合,通过搭建RT-LAB半实物实时仿真平台对基波电压幅值相位进行检测验证。实验结果表明:在dq坐标系下同时滤除DDC与高次谐波干扰信号的检测算法响应时间仅为20 ms,验证了所提算法的有效性以及分析结论的正确性。
