下垂控制孤岛微电网的三相不对称随机潮流计算方法研究

发布时间：2018-04-04 22:11

本文选题：下垂控制　切入点：频率修正模块　出处：《西安理工大学》2017年硕士论文

【摘要】：微电网是一个微型发、配、用电系统,由分布式电源、储能系统、能量转换装置、负荷等组成。分布式电源具有分散性、不确定性、出力较小和靠近用电负荷等特点,使得微电网与传统电网的系统结构差别较大,尤其在微电网处于孤岛运行模式时表现更为明显,此时传统电网的潮流计算方法将不再适用于微电网。本文主要研究孤岛微电网的稳态模型和潮流计算方法,为孤岛微电网的电压和功率分布提供理论依据。首先将微电源从输出功率的角度分为两类:可控微电源和不可控微电源。对于可控微电源,如蓄电池、燃汽轮机等,将其看成松弛的PQ节点,采用下垂控制计及频率的变化,根据每次迭代的电压和频率更新微电源的出力。对于不可控微电源,如风机、光伏等,在潮流计算中将其视为PQ节点,考虑到光强、风速等变化的随机性,对其出力进行随机模拟以得到它们的输出功率。根据孤岛微电网的实际情况,选用改进的牛拉法来进行潮流计算。此算法采用全节点的雅可比矩阵,不设置平衡节点,并通过在雅可比矩阵中引入有功和无功偏差对频率偏差的偏导模块来修正系统的频率,再通过反复迭代求得系统的潮流解。针对三相系统,本文采用序分量法进行三相潮流计算,其正序网络采用改进的牛拉法进行潮流计算,负序和零序网络均采用高斯法进行潮流计算。对于微电网的随机性问题,本文在确定性潮流的基础上引入随机潮流,采用蒙特卡洛法对不可控微电源和随机负荷的出力进行模拟,然后根据多次模拟的功率值分别进行多次潮流计算,最后通过对统计结果的分析,得到孤岛微电网的电压、频率等参数的概率特征。采用MATLAB语言编写了孤岛微电网的三相随机潮流计算程序,利用IEEE33节点算例验证了基于下垂控制孤岛微电网随机潮流算法的正确性。
[Abstract]:Micro grid is a miniature, with power system, the distributed power, energy storage system, energy conversion device, load etc.. Distributed power is decentralized, uncertainty, and small output close to the power load characteristics, the difference between micro grid and traditional power grid system structure greatly, especially in the micro grid in island operation mode is more obvious, the trend of the traditional grid calculation method will no longer apply to micro grid. Calculation method of steady state model and the trend of this paper mainly studies the island micro grid, for voltage and power distribution and provide a theoretical basis for the island micro grid. The micro power output power from the point of view two: controllable micro power and controllable micro power. For the controllable micro power supply, such as batteries, gas turbine, as PQ node relaxation, the change of droop control and frequency meter, according to each iteration The output voltage and frequency of micro power generation update. The uncontrolled micro power supply, such as wind, photovoltaic, calculation, as the PQ node in the trend, considering the randomness of light intensity, wind speed changes, the output of random simulation to obtain their output power. According to the actual situation of the island micro grid selection, improved Niulafalai flow calculation. This algorithm uses the Jacobi matrix of all nodes, do not set the balance node, and by the Jacobi matrix is introduced in the active and reactive power deviation on the frequency deviation of the partial module to correct the frequency of the system, and then through the iterative algorithm to solve the system. For three-phase power flow solution system, this paper adopts sequence component method three phase power flow calculation, the positive sequence network using the improved Newton method for power flow calculation, negative and zero sequence network using Gauss method for power flow calculation. For the random micro grid The problem, based on the deterministic trend on the introduction of stochastic trend output by using Monte Carlo method of controllable micro power and random load is simulated, then according to the power of many simulation values were repeated power flow calculation, and finally through the statistical analysis of the results obtained, the voltage of isolated microgrid, the probability characteristic frequency parameters the use of MATLAB language. The island micro grid three-phase stochastic power flow calculation procedures, examples validate the droop control of isolated microgrid stochastic power flow algorithm based on IEEE33 using the node.

【学位授予单位】：西安理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM744

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