【作者】 郭鹏；

【导师】 刘文颖；

【作者基本信息】 华北电力大学(北京) ， 电力系统及其自动化， 2017， 博士

【摘要】 随着我国风电的快速发展,在增加电力供应、缓解阶段性电力需求和供应之间的矛盾的同时,也为我国电网运营带来了新的挑战。一方面由于风电的波动性和不可控性使得电网调峰压力不断加大,风电并网与消纳问题越来越突出,弃风现象越发普遍;另一方面,风电出力的间歇性、随机性和波动性以及远距离输送使得风电集群接入电网网损也呈激增趋势,主要表现在三个方面:1)风电功率波动造成的网损特性复杂化;2)风电功率波动引起电压波动进而造成网损特性复杂化;3)逆向调峰模式引起的网损特性复杂化。因此如何在保证风电消纳水平不变的基础上,降低风电接入电网的网损成为亟待解决的关键问题,而传统的源-网协调控制方法无法满足风电接入电网的降损需求。因此,本文深入研究了风电集群接入对网损的影响机理,揭示了含风电集群接入电网的网损复杂特性;分析了不同有功无功调控设备的运行特性,在此基础上,提出了荷-网-源协调降损控制模式,并对荷-网-源有功无功解耦/耦合协调降损控制方法进行深入研究,取得以下创新性成果:针对风电接入引起的网损,从有功功率波动、电压波动以及常规电源逆向调峰三个角度深入研究风电对网损的影响机理;针对有功功率波动引起的网损,研究风电出力水平、风电波动幅度以及风电波动速率对网损的影响机理;针对电压波动引起的网损,研究风电波动对电压波动的影响以及电压波动对网损的影响,进而研究风电波动引起电压波动造成的网损增加机理;针对逆向调峰引起的网损,研究风电出力增加时对网损的影响机理;最后基于网损公式的全微分形式,提出含风电集群接入电网的网损复杂特性,与传统电网损耗特性有着本质的不同。并在深入分析荷-网-源有功无功调控设备运行及控制特性的基础上,结合上述网损复杂特性,提出荷-网-源协调降损控制模式,为提出荷-网-源协调降损控制方法奠定坚实的基础。深入分析高载能负荷(含离散型及连续型高载能负荷)、常规电源运行控制特性的差异以及不同时间尺度风电功率预测信息误差,建立多时间尺度荷-网-源有功协调降损控制模型;日前有功控制模型以离散型高载能负荷为调控对象,抑制风电大规模波动引起的网损增加,日内有功控制以常规电源及连续型高载能负荷为调控对象,平息日内风电随机性波动引起的网损;为了求解上述模型,提出收敛速度快并且具备全局优化能力的模拟退火-逐步优化算法,既可得到网损全局最优解,而且可以有效减少计算时间,显著提高计算效率;并在此基础上,提出荷-网-源有功协调降损控制方法。针对风电功率波动引起的电网电压波动从而增加的电网损耗,提出荷-网-源多类型无功补偿装置共同参与的多时间尺度无功降损控制模型;日前无功控制模型通过优化电容/电抗器组投切计划、有载调压变压器分接头档位,抑制电压波动幅度,降低网损;日内无功控制通过优化常规电源、SVC/SVG无功出力等连续型无功补偿设备,达到了全局优化降损的目的,进一步降低网损;并在此基础上,提出荷-网-源无功协调降损控制方法。基于节点电压大小与相角对节点注入有功功率和无功功率的响应灵敏度指标,提出荷-网-源有功无功解耦/耦合协调控制条件;并提出荷-网-源有功无功耦.合协调降损二层优化模型,上层优化模型进行有功协调控制,下层优化模型进行无功协调控制,二层计算结果互相传递、交叉迭代优化,可实现有功无功耦合运行状态的全网优化降损;最后,提出了风电集群接入电网的荷-网-源协调降损控制方法,可有效降低风电集群接入电网网损。更多还原

【Abstract】 With the rapid development of wind power in China,the power supply has increased,the contradiction between the power supply and demand is eased,but it also brings about new challenges to China’s power grid operation.On the one hand,due to the volatility and uncontrollability of wind power,the peak load regulation of power grid is getting more difficult,leading to the prominence of the problem of wind power interconnection and consumption,and the problem of the wind power curtailment.On the other hand,the intermittent,randomness and fluctuation of wind power output as well as its long-distance transmission make the losses of power grid with wind power integration get more prominent,which can be shown in three aspects:1)wind power fluctuations causes the complexity of the characteristics of power grid losses;2)voltage fluctuations by wind power fluctuations causes the complexity of the characteristics of power grid losses;3)the mode of reserve-peak load regulation causes the complexity of the characteristics of power grid losses.Therefore,how to reduce the losses of power grid with wind power integration on the basis of ensuring the consumption of wind power becomes a key problem to be solved,however,the traditional source-grid coordinated control method can no longer meet the needs of loss reduction of grid with wind power integration.In this paper,the influence mechanism of wind power integration on grid losses is studied in deep,and the complexity of the characteristics of grid losses with wind power integration is put forward.The operating characteristics of different active and reactive power equipment are analyzed.On this basis,the loss reduction mode of coordinated control of load,grid and source,and in-depth study of decoupling and coupling coordinated control method of the active power and reactive power is put forward,in summary,this article achieved the following innovative achievements:In dealing with the losses of power grid with wind integration,three aspect,i.e.the active power fluctuation,wind power fluctuation and the reserve-peak load regulation by regular generators are analyzed.Aiming at the grid losses caused by active power fluctuation,the influence mechanism of wind power output level,wind power fluctuation amplitude and wind power fluctuation rate on grid losses is studied.The influence of wind power fluctuation on voltage fluctuation and the influence of voltage fluctuation on grid losses are studied,and the mechanism of grid losses caused by voltage fluctuation is studied.The influence mechanism of wind power level on the grid losses is analyzed concerning the reserve-peak load regulation.Finally,based on the fully differential form of the grid losses formula,the complicated characteristics of the losses of grid with wind power integration is proposed,which is far different from the traditional power grid losses characteristic.Based on the analysis of the operating characteristics of the equipment of load-grid-source,as well as the complexity analysis of the losses of grid with wind power integration above,the loss-reduction control mode of load-grid-source is proposed,which is a foundation of load-grid-source coordinated control method.The difference of control characteristics of the high energy load and the conventional power generator and the wind power forecasting errors at different time scales are analyzed,and the multi-time scale active power losses-reduction control model of load-grid-source is established.The day ahead active control model takes the discrete high energy load as the target,depressing the grid losses caused by the large-scale fluctuation of the wind power,while the intra-day active control takes the conventional generators and continuous high energy load as the target,dissipating the grid losses caused by the randomness of the wind power.Regarding to the model proposed,the simulated annealing-progressive optimality algorithm is proposed,which can obtain the global optimal solution while reduces the computation time.On this basis,the active power losses-reduction control method of load-grid-source is proposed.Aiming at the grid losses caused by voltage fluctuation by wind power fluctuation,a multi-time scale reactive power loss-reduction control model with various reactive power compensation devices is proposed.The day ahead reactive power control model concerns the optimization of the discrete capacitor and reactor,and the transformer tap position,to suppress the voltage fluctuation degree and reduce the grid losses;while optimizing the continuous reactive power compensation equipment such as conventional power supply,SVC/SVG reactive power output intraday to achieve the purpose of the overall optimization of power flow,so as to further reducing the grid losses;and on this basis,the reactive power reduction control method is proposed.Based on the response sensitivity index of the input power(active and reactive)the node on node voltage(amplitude,phase angle),the load-grid-source decoupling/coupling coordinated control criterion is proposed.The two-layer optimization model,i.e.the upper-layer optimization model dealt with active power coordination control,while the lower-level optimization model dealt with the reactive power coordinated control is proposed.The two-layer transmitted each calculation results to each other and the optimization keeps cross-iterative,guaranteeing the active and reactive power coupling optimization of the whole power system can be achieved.Finally,a loss-reduction control method of load-grid-source is proposed,which can effectively reduce the loss of grid with wind power integration.更多还原