基于增益系数优化的直流电网下垂控制策略  

A droop control strategy for a DC grid based on gain coefficient optimization

作　　者：候文佚 龚雁峰 HOU Wenyi;GONG Yanfeng(North China Electric Power University,Beijing 102206,China;Power China Jiangxi Electric Power Engineering CO.,LTD.,Nanchang 330096,China)

机构地区：[1]华北电力大学,北京102206 [2]中国电建江西省电力设计院有限公司,江西南昌330096

出　　处：《电力系统保护与控制》2021年第24期132-140,共9页Power System Protection and Control

基　　金：国家电网公司总部科技项目资助(SGTYHT/16-JS-198)。

摘　　要：直流电压是衡量直流电网功率平衡的重要指标。系统功率的较大扰动使直流电压严重偏离额定值,影响了直流电网的安全稳定运行。下垂控制可实现多点直流电压控制,是直流电网协调控制的重要手段。为了应对直流电网单个换流站故障退出运行后造成的直流电压偏差超出其安全阈值,提出了基于增益系数优化的新型直流电网下垂控制策略。该控制策略考虑了直流电网中换流站容量限制,根据换流站整流和逆变的运行模式,分别给出不同的下垂控制器增益系数,对各个换流站进行优化功率分配,以此达到减小直流电压偏差量的目标。通过与传统下垂控制方法比较,突出了所提方法采用不同增益系数带来的优异性。并对两种方法进行PSCAD仿真验证,仿真结果表明所提方法在直流电网面对较大功率缺失和溢出情况下的直流电压调节效果优于传统方法。DC voltage is an important indicator in measuring the power balance of a DC grid.A large disturbance in system power makes the DC voltage seriously deviate from the rated value.Droop control can realize multi-point DC voltage control,and this is the main means for coordinated control of the DC grid.In order to deal with the DC voltage deviation exceeding the safety threshold after the failure of a single converter station in a DC network,this paper optimizes the design of the gain parameters of the DC grid droop control.It considers the capacity limit of the converter station in the DC grid.Different droop controller coefficients are given based on the rectifying converting operation modes of the converter station.The power distribution of each converter station is optimized to achieve the goal of reducing the deviation of the DC voltage.The superiority of the proposed different gain coefficient methods over traditional methods is demonstrated.The two methods are simulated and verified using the PSCAD.Simulation results show that the proposed method can regulate the DC voltage in the case of large power loss and overflow in the DC grid.The effect is better than traditional methods.

关 键 词：直流电网 下垂控制 增益系数 优化设计 

分 类 号：TM721.1[电气工程—电力系统及自动化]