For demonstrating a multiterminal voltage-source converter(VSC)-based high-voltage DC(HVDC)(VSCHVDC) project, this study puts forward a technical route for calculating the power flow in a 500-kV VSC-HVDC power grid in...For demonstrating a multiterminal voltage-source converter(VSC)-based high-voltage DC(HVDC)(VSCHVDC) project, this study puts forward a technical route for calculating the power flow in a 500-kV VSC-HVDC power grid in comparison with that of an AC power grid. The Jacobian matrix used in the power-flow calculation was deduced through methods such as Newton–Laphson iteration and Taylor series expansion. Further, the operation effect of powerflow calculation on a true bipolar VSC-HVDC power grid was analyzed briefly. The elements of the Jacobian matrix corresponding to VSC were studied under the mode of droop control and the control strategy of VSC-HVDC power grid was analyzed in detail. The power-flow calculation model for VSC-HVDC power grid of the master–slave control mode was simplified using the PQ decomposition method of the power-flow calculation of an AC power grid. Moreover, a four-terminal model of the Zhangbei VSC-HVDC demonstration project was established and tested on MATLAB. The simulation results under two kinds of operating conditions were analyzed and compared to the results of BPA; the deviation between the power-flow results was studied. The results show that the proposed calculation method can provide a feasible support for calculating the power flow in VSC-HVDC grids.展开更多
在实现“双碳”目标的背景下,城市轨道交通需要实现节能低碳运行。现有牵引供电系统(traction power supply system,TPSS)采用下垂控制策略存在再生制动能量利用率低、缺乏对系统潮流主动有效控制及优化手段等问题。该文分析双向变流器...在实现“双碳”目标的背景下,城市轨道交通需要实现节能低碳运行。现有牵引供电系统(traction power supply system,TPSS)采用下垂控制策略存在再生制动能量利用率低、缺乏对系统潮流主动有效控制及优化手段等问题。该文分析双向变流器的下垂参数对系统用电量的影响,进而提出一种实现牵引负荷功率最优分配的协同控制方法,该方法对双向变流器的下垂参数实时优化和调整,促进机车再生制动能量的流动,有效提高再生制动能量利用率,显著提升系统协同控制性能。经仿真计算,采用该方法可年节约0.17亿k W·h电量,有效助力城市轨道交通牵引供电系统安全、经济运行。展开更多
【目的】考虑系统清洁低碳的前提下,综合能源系统中能源产品定价与市场用户的经济利益和能源运营商的盈利能力密切相关。为此,对含电转气-碳捕集电厂(power to gas-carbon capture power plant,P2G-CCPP)的综合能源系统(integrated ener...【目的】考虑系统清洁低碳的前提下,综合能源系统中能源产品定价与市场用户的经济利益和能源运营商的盈利能力密切相关。为此,对含电转气-碳捕集电厂(power to gas-carbon capture power plant,P2G-CCPP)的综合能源系统(integrated energy system,IES)进行㶲经济分析。【方法】从㶲视角出发,兼顾能量的量与质,针对不同能流进行㶲值计算,建立㶲流计算子模型。将系统低碳经济性引入㶲经济分析中,将碳排放权交易成本、碳捕集能耗成本及碳封存成本纳入非能量成本中,建立㶲经济成本分摊子模型。相较于传统定价方法,考虑了碳成本及能量品位差异对系统冷热电单位㶲成本的影响,体现优质优价原则。【结果】仿真算例表明引入P2G-CCPP联动系统能够提高系统低碳减排能力,实现成本合理分摊。【结论】含P2G-CCPP机组的综合能源系统能够有效削减系统总成本及冷热电单位成本,增强了碳利用和燃气生产消费的节能减排途径,具有显著的经济及社会效益。展开更多
合环转供电是提高供电可靠性的关键手段,但直接合环可能产生较大冲击电流影响电网运行安全性。采用旋转潮流控制器(rotary power flow controller,RPFC)的方式能够实现台区的零感知合环,但电压调节轨迹不当将会带来RPFC接入点的电压越...合环转供电是提高供电可靠性的关键手段,但直接合环可能产生较大冲击电流影响电网运行安全性。采用旋转潮流控制器(rotary power flow controller,RPFC)的方式能够实现台区的零感知合环,但电压调节轨迹不当将会带来RPFC接入点的电压越限问题。对此,提出一种基于两阶段最优路径的RPFC配电网柔性合环方法。首先,对输出电压运行轨迹进行合理规划,将其分为两阶段:第1阶段要求合环点两端电压相位一致并约束电压幅值相等,实现端电压的平稳过渡;第2阶段在相位一致的基础上,控制RPFC输出电压至目标值,使合环点两端电压幅值一致。然后,采用分相量夹角计算和旋转角协调控制,选择就近的旋转角设定值作为目标值,从而实现合环点两端电压无差调节;最后,仿真和实验对比分析所提方法将电压越限至少降低至30%,展示RPFC在实现配电网柔性合环中的重要应用价值。展开更多
基金supported by the State Grid Corporation of China Headquarter technology project (52010118000K)
文摘For demonstrating a multiterminal voltage-source converter(VSC)-based high-voltage DC(HVDC)(VSCHVDC) project, this study puts forward a technical route for calculating the power flow in a 500-kV VSC-HVDC power grid in comparison with that of an AC power grid. The Jacobian matrix used in the power-flow calculation was deduced through methods such as Newton–Laphson iteration and Taylor series expansion. Further, the operation effect of powerflow calculation on a true bipolar VSC-HVDC power grid was analyzed briefly. The elements of the Jacobian matrix corresponding to VSC were studied under the mode of droop control and the control strategy of VSC-HVDC power grid was analyzed in detail. The power-flow calculation model for VSC-HVDC power grid of the master–slave control mode was simplified using the PQ decomposition method of the power-flow calculation of an AC power grid. Moreover, a four-terminal model of the Zhangbei VSC-HVDC demonstration project was established and tested on MATLAB. The simulation results under two kinds of operating conditions were analyzed and compared to the results of BPA; the deviation between the power-flow results was studied. The results show that the proposed calculation method can provide a feasible support for calculating the power flow in VSC-HVDC grids.
文摘在实现“双碳”目标的背景下,城市轨道交通需要实现节能低碳运行。现有牵引供电系统(traction power supply system,TPSS)采用下垂控制策略存在再生制动能量利用率低、缺乏对系统潮流主动有效控制及优化手段等问题。该文分析双向变流器的下垂参数对系统用电量的影响,进而提出一种实现牵引负荷功率最优分配的协同控制方法,该方法对双向变流器的下垂参数实时优化和调整,促进机车再生制动能量的流动,有效提高再生制动能量利用率,显著提升系统协同控制性能。经仿真计算,采用该方法可年节约0.17亿k W·h电量,有效助力城市轨道交通牵引供电系统安全、经济运行。
文摘【目的】考虑系统清洁低碳的前提下,综合能源系统中能源产品定价与市场用户的经济利益和能源运营商的盈利能力密切相关。为此,对含电转气-碳捕集电厂(power to gas-carbon capture power plant,P2G-CCPP)的综合能源系统(integrated energy system,IES)进行㶲经济分析。【方法】从㶲视角出发,兼顾能量的量与质,针对不同能流进行㶲值计算,建立㶲流计算子模型。将系统低碳经济性引入㶲经济分析中,将碳排放权交易成本、碳捕集能耗成本及碳封存成本纳入非能量成本中,建立㶲经济成本分摊子模型。相较于传统定价方法,考虑了碳成本及能量品位差异对系统冷热电单位㶲成本的影响,体现优质优价原则。【结果】仿真算例表明引入P2G-CCPP联动系统能够提高系统低碳减排能力,实现成本合理分摊。【结论】含P2G-CCPP机组的综合能源系统能够有效削减系统总成本及冷热电单位成本,增强了碳利用和燃气生产消费的节能减排途径,具有显著的经济及社会效益。
文摘合环转供电是提高供电可靠性的关键手段,但直接合环可能产生较大冲击电流影响电网运行安全性。采用旋转潮流控制器(rotary power flow controller,RPFC)的方式能够实现台区的零感知合环,但电压调节轨迹不当将会带来RPFC接入点的电压越限问题。对此,提出一种基于两阶段最优路径的RPFC配电网柔性合环方法。首先,对输出电压运行轨迹进行合理规划,将其分为两阶段:第1阶段要求合环点两端电压相位一致并约束电压幅值相等,实现端电压的平稳过渡;第2阶段在相位一致的基础上,控制RPFC输出电压至目标值,使合环点两端电压幅值一致。然后,采用分相量夹角计算和旋转角协调控制,选择就近的旋转角设定值作为目标值,从而实现合环点两端电压无差调节;最后,仿真和实验对比分析所提方法将电压越限至少降低至30%,展示RPFC在实现配电网柔性合环中的重要应用价值。
