面向一次调频的炉—机—网协调控制方法研究

发布时间：2018-12-17 05:55

【摘要】：风电等新能源的波动性使超临界机组的功率频繁波动,进而影响直流锅炉的寿命及经济性。本文针对超临界机组设计炉、机、网协调的一次调频控制方法,既降低锅炉寿命损耗,又增加了电力系统调频能力,达到网源双赢。首先,建立用于一次调频分析的炉、机、网模型。依据直流锅炉的能量、质量、动量方程,建立能反映锅炉能量动态的非线性模型。依据汽轮机及其调节系统的动态特性,建立用于一次调频分析的汽轮机线性模型。依据不同类型汽轮机的动态特性,建立包含不同类型机组的电力系统一次调频模型,以研究炉-机-网协调控制方法对锅炉安全、系统调频的影响。其次,依据网源能量状态设计炉-机-网协调控制策略。为了使网源能量相协调,本文定量分析锅炉能量偏差与电力系统功率偏差,在汽轮机功率给定处增加了反映锅炉能量与系统需求的修正量,并针对不同的电网频率和不同的锅炉主蒸汽压力设计不同的修正量。最终效果是锅炉能量较高(低)时,多参与电网频率较低(高)时段的调节,而少参与频率较高(低)时段的调节,从而达到网源双赢。不同网源能量状态下的仿真表明,炉-机-网协调控制方法更利于消除频差,且使直流炉主蒸汽压力趋于平稳。最后,定量研究炉-机-网协调控制方法对锅炉寿命、系统CPS值、系统潮流的影响。依据应力循环次数计算锅炉寿命损耗,仿真表明,新方法使锅炉水冷壁、过热器的寿命分别提高约3%、7%。基于包含不同类型机组的电力系统调频模型,对比该方法使用前后电力系统的调频性能,结果表明,炉-机-网协调控制方法对CPS改善效果明显。基于节点注入功率与系统潮流的关系,研究该方法广泛应用时潮流的变化,结果表明,炉-机-网协调控制方法不会对系统潮流造成大幅影响。
[Abstract]:The fluctuation of new energy sources, such as wind power, makes the power of supercritical units fluctuate frequently, thus affecting the life and economy of once-through boilers. In this paper, the primary frequency modulation control method for supercritical unit is designed, which not only reduces the boiler life loss, but also increases the power system frequency modulation ability to achieve a win-win network source. First, the model of furnace, machine and net for primary frequency modulation analysis is established. According to the energy, mass and momentum equations of once-through boiler, a nonlinear model which can reflect the energy dynamics of the boiler is established. According to the dynamic characteristics of steam turbine and its regulating system, a linear model of steam turbine for primary frequency modulation analysis is established. According to the dynamic characteristics of different types of steam turbines, the primary frequency modulation model of power system including different types of units is established to study the influence of the coordinated control method of boiler, machine and network on boiler safety and system frequency modulation. Secondly, the coordinated control strategy of furnace-machine-network is designed according to the energy state of network source. In order to coordinate the energy of grid sources, the boiler energy deviation and the power deviation of power system are quantitatively analyzed in this paper, and the correction quantity reflecting the boiler energy and system requirement is added to the given power of steam turbine. Different correction quantities are designed for different power network frequency and boiler main steam pressure. The final effect is that when the boiler energy is high (low), it is more involved in the regulation of the lower (high) period of power grid frequency, and less in the regulation of the period of higher (low) frequency, thus achieving the win-win situation of the network source. The simulation results show that the coordinated control method is more favorable to eliminate the frequency difference and make the main steam pressure of the direct current furnace more stable. Finally, the influence of boiler-machine-network coordinated control method on boiler life, system CPS value and system power flow is studied quantitatively. The life loss of boiler is calculated according to the number of stress cycles. The simulation results show that the new method can increase the service life of boiler water wall and superheater by about 3 / 7 respectively. Based on the power system FM model with different types of units, the FM performance of the power system before and after the use of this method is compared. The results show that the steer-machine-network coordinated control method can improve the CPS obviously. Based on the relationship between nodal injection power and system power flow, the variation of power flow when the method is widely used is studied. The results show that the coordinated control method of furnace machine network has no significant influence on the power flow of the system.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM621

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