海洋孤岛微电网协调控制策略研究

发布时间：2019-06-29 08:23

【摘要】：由于传统的大陆电网向海岛具有输电线路远、成本高、可靠性低的特点,同时海岛上拥有丰富的可再生资源,促进海岛经济稳定发展的一项重要措施是建立稳定可靠的海岛微电网。为了实现海岛微电网安全、稳定、经济的运行,同时针对分布式发电单元出现的问题,本文具体研究内容如下:本文首先介绍了微电网的研究现状,以砣矶岛为研究对象,然后深入研究了光伏发电系统,并进行了数学建模,针对利用DC/DC方法来进行最大功率点跟踪(MPPT)存在负载阻抗只能进行单方向的转换的问题,本文采用改进的粒子群算法进行MPPT控制,并进行了仿真验证。其次,对风力发电系统进行研究,了解典型的风力发电形式,对砣矶岛原有的风力发电机组进行改进,重点研究了在风速超过额定风速的情况下,运用桨距角控制策略,目的是使得机组输出的功率快速保持在额定功率附近,仿真结果可以看出该方法控制效果良好。由于光伏、风力等发电单元具有随机性和间歇性的特点,容易造成直流母线电压的不稳定,为此在采用蓄电池和超级电容双储能控制策略的基础上,提出总有一组电池处于放电状态,维持直流母线电压稳定的方法,同时可以快速抑制其波动。最后,对并网逆变器进行研究,针对并网谐波对电能质量影响较大,提出一种PDFI(比例延时反馈积分)控制和模糊控制的复合控制方法,不仅可以抑制电网谐波,而且可以快速准确地跟踪并网参考电流,仿真表明,该方法具有良好的控制效果,有效地提高了电能质量。
[Abstract]:Because the traditional continental power grid to the island has the characteristics of long transmission line, high cost and low reliability, and there are abundant renewable resources on the island, one of the important measures to promote the stable development of the island economy is to establish a stable and reliable island microgrid. In order to realize the safe, stable and economical operation of island microgrid, and aiming at the problems of distributed power generation unit, the specific research contents of this paper are as follows: firstly, this paper introduces the research status of microgrid, takes the island as the research object, then deeply studies the photovoltaic power generation system, and carries on the mathematical modeling. In order to solve the problem that the load impedance can only be converted in one direction when the maximum power point tracking (MPPT) is carried out by using DC/DC method, the improved particle swarm optimization algorithm is used for MPPT control, and the simulation results are verified by simulation. Secondly, the wind power generation system is studied, the typical wind power generation form is understood, and the original wind turbine in Tuoji Island is improved. When the wind speed exceeds the rated wind speed, the pitch angle control strategy is used in order to keep the output power of the unit near the rated power quickly. The simulation results show that the control effect of this method is good. Because photovoltaic, wind power and other power generation units have the characteristics of randomness and intermittent, it is easy to cause the instability of DC bus voltage. On the basis of adopting the double energy storage control strategy of battery and supercapacitor, a method of maintaining DC bus voltage stability is proposed, which can keep the DC bus voltage stable, and at the same time, it can restrain the fluctuation of DC bus voltage quickly. Finally, the grid-connected inverter is studied. Aiming at the great influence of grid-connected harmonics on power quality, a compound control method of PDFI (proportional delay feedback integral) control and fuzzy control is proposed, which can not only suppress the harmonics of power grid, but also track the reference current of grid-connected quickly and accurately. Simulation results show that this method has good control effect and effectively improves power quality.
【学位授予单位】：江苏科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM727

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