引入分位数概念来改善评估稳定性,并采用序贯最小优化策略来提高计算速度.首先,采用新能源和系统特征构建表征电力系统暂态稳定性的原始特征集,有效表征新能源接入对暂态稳定性的影响;然后,引入分位数来改变稳定类与不稳定类的最近点位置,降低由于新能源的波动性和不确定性对评估稳定性的影响,进而引入序贯最小优化策略,将弹球损失支持向量机的高维优化问题转化为多个低维优化问题,有效提高计算速度.最后,以修改后的IEEE-39测试算例进行仿真分析,验证所提方法的有效性和准确性.

为提高大型区域互联系统连续潮流的计算效率,提出一种改进的基于快速解耦电力系统连续潮流并行计算方法.通过在校正阶段采用快速解耦法求解潮流方程,根据系统的阻抗参数和功率增长方向构造修正方程组的系数矩阵,对潮流方程修正方程组进行预处理,并采用基于CPU-GPU混合架构加速的稳定双共轭梯度法进行求解.基于IEEE-118节点系统、Case13802等多个不同规模测试系统的算例分析表明,该改进算法有效提高了连续潮流的计算速度.

为有效预测大扰动过程中直流送端系统的暂态过电压,提出一种基于卷积神经网络(convolutional neural networks,CNN)的直流送端系统暂态过电压估算方法.首先,基于CNN输入特征构建的基本原理,搭建具有多层隐含层的非线性网络结构,将广域量测装置采集的各节点电压、相角及功率作为输入层,依据电网节点的拓补关系及故障发生到切除的时间顺序进行拼接,得到表征电网状态的矩阵.然后,优化调整CNN的超参数,采用梯度下降法进行有监督训练,通过逐层优化输入层与卷积层之间的权重矩阵,实现关键特征值的自动提取,同时利用CNN的深层架构构建暂态过电压与输入数据间的映射模型,快速准确地估算直流送端系统暂态过电压.最后,对修改后的Nordic32交直流混合系统和广东电网系统进行分析,验证该方法的有效性和准确性.

提出一种基于数据驱动的电力系统动态等值方法.根据发电机同调关系与节点间电气距离,明确网络划分原则;以所研究区域边界母线电压及联络线功率作为输入,辨识外部区域等值发电机的暂态电抗;以等值发电机有功输出与原始系统联络线有功功率误差最小为目标函数,基于最小二乘辨识等值发电机的惯性常数TJ和阻尼系数D,进而构建等值系统;以动曲线均方根误差及拟合度指标,定量评价等值系统;最后将所提方法应用于修改的IEEE-68节点测试系统和张北四端柔性直流电网工程,结果验证了所提方法的正确性和有效性.

基于三线双极结构的高压直流(TWBS-HVDC)输电系统能够较大程度地发挥直流线路的输电能力,是一种实现交改直和线路增容改造的有效方式.针对TWBS-HVDC系统与双极直流系统在接线形式上的差异,文中提出了一种适用于两端TWBS-HVDC的直流侧短路故障电流计算方法.首先基于模块化多电平换流器(MMC)暂态等效电路建立两端TWBS-HVDC在不同直流侧故障发生至线路直流断路器动作阶段的暂态等效模型.以暂态等效电路中独立回路数和动态元件阶数为标准,将所有直流故障归纳为3类,分析推导各类故障下的状态方程,通过求解状态方程中系数矩阵的特征值和特征向量得到故障电流解析表达式.最后在MATLAB/Simulink数字仿真平台中,搭建两端TWBS-HVDC模型进行仿真验证,结果验证了所提TWBS-HVDC直流侧短路故障状态方程求解法的准确性和有效性,为直流断路器选型和限流电抗器参数整定提供了可靠依据.

为抑制风电经高压直流外送方式下的直流送端系统暂态过电压,提出一种直流和风电控制参数协调优化方法.首先,从整流站与风电场之间的无功转换角度分析了直流送端系统暂态过电压的产生机理,进而从系统无功特性入手研究了直流整流侧、风电转子侧变流器控制参数影响暂态过电压的机理,为抑制暂态过电压的控制参数协调优化提供了理论依据.然后,构建了以直流送端系统暂态过电压峰值最小为目标的优化模型,通过联合调用的方式,可在电磁暂态模型准确模拟交直流系统电磁暂态过程的基础上,进一步采用改进粒子群优化算法协调优化直流和风电控制参数,从而有效抑制直流送端系统暂态过电压.最后,通过修改后的4机11节点系统和新英格兰39节点系统的仿真分析,验证了所提方法的有效性和准确性.

AC system equivalence is needed in HIL(Hardware-In-Loop) test to give the considerations of simulation scale and interaction between AC and DC,for which,a method of large-scale AC system equivalence is proposed based on the principle that the short circuit capacities before and after equivalence should be consistent.The rated capacity and access reactance of equivalent generator are set according to the short circuit current of equivalent node.A new criterion is proposed based on the short circuit current contribution ratio according to the relationship between short circuit current and dynamic system characteristics,which is used to choose the dominative controller of equivalent generator and calculate the controller parameters.The static Ward equivalence is improved to eliminate the conditions of negative resistance and negative generator active power output.As an example,the system voltages,power flows and short circuit capacities before and after equivalence are compared and the post-fault dynamic response characteristics are analyzed,verifying the effectiveness of the proposed method.

In this paper,a fast method based on critical failure impedance boundary is proposed to determine the commutation failure of multi-infeed HVDC system. Based on the nodal impedance matrix, leading in the definition of nodal voltage influencing factor( VIF) to calculate the extinction angles of convert stations while three-phase grounding fault happens at any buses in AC system,and taking critical extinction angle as criteri-on. Using power system simulation software PSS/E,the simulation results of a two-infeed HVDC test system proved the effective and accuracy of the method,that derived in this paper which delimiting the commutation failure of multi-infeed HVDC system based on critical failure impedance boundaries.

Load demand control,steam press control,turbine-boiler coordinated control of one plant's 7# unit CCS are analyzed.The unit has a poor load demand response,and an unstable steam press.After optimization,the unit performs reputably in adjusted quality,and the security and economical efficiency are guaranteed.

随着现代工业的发展，DCS控制系统已经被广泛应用，并具备了一定的实践经验。本文主要介绍了DCS的应用功能，并简单分析了DCS的优点以及在应用中可能遇到的问题。

Based on the successful application of the LN2000 DCS in the biomass power plant in Huimin county,this essay summarizes the technological process and the system requirements of the biomass power plant as well as designing a control system for it with LN2000 DCS.Besides,this essay also focuses on the hardware configuration of the network structure of the DCS,the monitoring interface of the system,the control mode of the system and the major control system.

Based on the fuzzy control,this article presents a way of composing a fuzzy control inquiry platform,by using DCS conventional functional modules.Practical application has shown that it is easy to be realized with good control effects.

本论文通过分析火电厂的主蒸汽温度控制现状和影响过热汽温的主要因素,同时针对单元机组主汽温控制的滞后特性,提出了神经内分泌智能控制算法,此方法具有较好的鲁棒性、稳定性、快速响应性和抗干扰能力,为主汽温的复杂控制提出了一种新方法。

在循环流化床中对生物质和煤进行共气化实验,将生物质的混掺比例固定在50%,观察空气当量比ER和水蒸气/燃料质量比S/F对气体组分的影响,最终得到参数最优的共气化模型,为生物质、煤共气化的优化设计提供了一条可实现的现实途径。

Low pH of acid rain in China is a typical sulfuric acid rain. The smoke ejecting from the coal-fired power plants have a great amount of sulfur dioxide, which occupies 40%~50% of the total amount of sulfur dioxide emission in China. So controlling the total emissions of sulfur dioxide of coal-fired power plants becomes the key of preventing the acid rain pollution . The factors that affect the efficiency of desulfurization of FGD systems applied in power plants were analyzed, and the scheme of using DCS to enhance the rate of flue gas desulfurization program was proposed.