基于可控负荷优化利用的微电网频率调节策略研究

发布时间：2018-04-17 08:32

本文选题：微电网 + 频率控制　；参考：《北方工业大学》2017年硕士论文

【摘要】：频率是衡量电网系统电能质量的重要指标,也是维持电力系统稳定运行的关键因素。大量的间歇性可再生能源接入微电网系统时,由于可再生能源发电的输出功率具有随机性、波动性和突变性,以及电网的负荷功率时刻发生变化,容易导致微电网系统发电单元的发电功率与负荷用电功率出现功率不平衡现象,使得电网频率相对于其额定值将有不同程度的波动和偏移,对电力用户的用电质量造成较大影响。为减小系统频率偏差对用户造成的影响,传统的电力系统频率调节方式主要是通过调节发电机组容量,也可切断用户负荷,进行平衡发电侧与负荷侧之间的功率差,实现系统频率的稳定控制。与这些传统的调频方式相比,部分可控负荷因其快速响应特性、储能特性、高可控特性以及零污染等优势,成为电力系统频率调节的主要研究对象。本文以空调为例,针对空调类温控负荷参与电力系统频率调节的方法展开研究。首先,对微电网系统的组成结构、运行控制结构以及各微电源逆变器的控制策略进行分析。考虑到在微电网运行过程中,大量可控负荷的参与会对微电网稳定运行产生一定的影响,故需选取合适的微电网运行控制结构,保证微电网系统的稳定性。此外,通过模拟电力系统的调频原理,使参与调频的储能装置具有能够进行系统频率二次调节的功能,并通过算例仿真,分析微电网系统在发生各种故障的情况下,储能装置二次调频策略对微电网系统作出的响应,以便将其应用到与可控负荷群联合对微电网频率进行调节的过程中。其次,在空调类温控负荷有效参与系统频率的稳定控制时,为使微电网系统频率测量值可以更好的接近于系统频率额定值,需要完成下面几项工作:1、对空调类温控负荷的工作原理、工作特性进行分析,描述出符合空调的数学模型。根据空调的温度变化特性,设计出空调负荷的控制策略,使其参与到微电网系统的频率调节过程中。2、为将微电网系统的频率偏差减小至预定的允许范围内,在上述空调负荷群参与微电网系统调频的同时,还需要建立合适的储能装置调频模型,二者协同完成微电网系统的调频过程。最后,为证实空调类温控负荷联合储能装置对系统频率稳定控制的有效性,需要对空调、储能装置参与系统频率稳定与控制的过程进行仿真验证。通过构建孤立微电网系统模型,对算例进行仿真分析,得出了空调类温控负荷能够替代部分发电侧调频备用、空调类温控负荷对系统频率波动能够起到缓冲作用的结论,验证了空调类温控负荷联合储能装置调频策略对减小系统频率偏差的有效性。
[Abstract]:Frequency is an important index to measure the power quality of power system, and it is also the key factor to maintain the stable operation of power system.When a large number of intermittent renewable energy is connected to the microgrid system, the output power of renewable energy generation is random, fluctuating and abrupt, and the load power of the grid changes at all times.It is easy to cause power imbalance between generating power and load power in micro-grid system, which makes the frequency of power grid fluctuate and deviate in varying degrees relative to its rating.It has great influence on the power quality of electric power users.In order to reduce the influence of system frequency deviation on users, the traditional frequency regulation method of power system is mainly by regulating the capacity of generating units, and also cutting off the user load, and balancing the power difference between the generating side and the load side, so as to balance the power difference between the power generation side and the load side.The stable control of system frequency is realized.Compared with these traditional FM modes, partial controllable load becomes the main research object of frequency regulation for power system because of its advantages of fast response, energy storage, high controllability and zero pollution.In this paper, taking air conditioning as an example, the method of frequency regulation of power system with temperature control load of air conditioning is studied.Firstly, the structure, operation control structure and control strategy of microgrid inverter are analyzed.Considering that the participation of a large number of controllable loads will have a certain impact on the stable operation of microgrid in the process of microgrid operation, it is necessary to select appropriate microgrid operation control structure to ensure the stability of microgrid system.In addition, by simulating the principle of frequency modulation of power system, the energy storage device participating in frequency modulation has the function of secondary regulation of the frequency of the system. Through the simulation of an example, the microgrid system is analyzed in the case of various faults.The response of the secondary frequency modulation strategy of the energy storage device to the microgrid system so as to apply it to the process of regulating the frequency of the microgrid in conjunction with the controllable load group.Secondly, in order to make the frequency measurement value of microgrid system more close to the system frequency rating, when the temperature control load of air conditioning effectively participates in the stable control of the system frequency,It is necessary to finish the following work: 1, to analyze the working principle and working characteristics of the temperature control load of air conditioning class, and to describe the mathematical model that accords with the air conditioning.According to the temperature variation characteristics of air conditioning system, the control strategy of air conditioning load is designed to make it participate in the frequency regulation process of microgrid system. In order to reduce the frequency deviation of microgrid system to a predetermined allowable range,While the air conditioning load group is involved in the microgrid system FM, it is also necessary to establish a suitable FM model of the energy storage device, and the two systems cooperate to complete the FM process of the microgrid system.Finally, in order to verify the effectiveness of the system frequency stability control by the combined temperature control load storage device, it is necessary to simulate the process of the air conditioning and energy storage equipment participating in the frequency stability and control of the system.Based on the model of isolated microgrid system and the simulation analysis of an example, the conclusion is drawn that the temperature control load of air conditioning can replace the frequency modulation reserve of some generation side, and the temperature control load of air conditioning class can buffer the frequency fluctuation of the system.It is verified that the frequency modulation strategy of the combined temperature control load storage device of air conditioning system is effective to reduce the frequency deviation of the system.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM727;TM712

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