The synchronizing torque of a power system may be weakened by increasing installation of static power converters accompanied by renewable energy resources because they used to trade their favorable active power by syn...The synchronizing torque of a power system may be weakened by increasing installation of static power converters accompanied by renewable energy resources because they used to trade their favorable active power by synchronizing their output voltage with the one at the point of common coupling. In the circumstances, a concept of Virtual Synchronous Machine (VSM) is proposed, where the self-commutated power converters are emulating synchronous generators. This paper describes a converter control to contribute to enhancing the synchronizing torque. The proposed control is similar to the VSM but it simply realizes active power trades among power generation units including converter-based generators by modulating phase angles of their output voltages. Therefore, it can provide an effective support to regulate the system frequency where the total rated power of the converter-based generators increases as much as the one of conventional rotating generators like a microgrid. This paper especially focuses on its robustness where the number of converter-based generators is increased or they are dispersed in the power network. The effectiveness is verified by simulation study based on instantaneous values.展开更多
With the advent of phasor measurement unit (PMU) technology, the grid observability has got a new dimension. This facet of technology helps in getting the real-time and dynamic scenario of the grid operations which wa...With the advent of phasor measurement unit (PMU) technology, the grid observability has got a new dimension. This facet of technology helps in getting the real-time and dynamic scenario of the grid operations which was a remote possibility some decades before. Achieving this level of observability puts us at an advantage of responding to the system faults with reduced response time, and helps in restoring the grid stability within fraction of second. This paper demonstrates the detailed fault characterization from the PMU inputs, after illustrations from various real-time examples and different faults occurred in India. This paper tries to shed some light on areas where the accurate fault characterization can help the operator in taking the right decision for reliable grid operations.展开更多
远程终端单元(remote terminal unit, RTU)是当前电网中最主要的测量终端,但是其量测量没有统一时标,更新频率低,而且存在不确定性的传输时延。而同步相量测量单元(phasor measurement unit, PMU)具有高同步、高精度等特点,成为电力系...远程终端单元(remote terminal unit, RTU)是当前电网中最主要的测量终端,但是其量测量没有统一时标,更新频率低,而且存在不确定性的传输时延。而同步相量测量单元(phasor measurement unit, PMU)具有高同步、高精度等特点,成为电力系统中重要的数据采集装置。为协调利用这两种测量数据,首先归纳出RTU量测非同步的来源,分析了量测数据不同步对状态估计和潮流计算的影响,并给出了相关的验证结果。并提出基于能量交互算子的量测数据相关性分析方法。该方法应用同步数据间相关性最大的原理,利用PMU所产生的精确数据来同步RTU数据,为混合测量系统确定测量基准时刻。通过对IEEE39节点电网和广东83节点实际电网的仿真,结果表明该方法能有效校正量测数据非同步以及改善状态估计和潮流计算精度。展开更多
为提升含高比例电力电子设备的电力系统暂态稳定性,提出一种基于广域测量系统(wide area measurement system,WAMS)的静止无功补偿器(static var compensator,SVC)优化控制策略。通过同步相量测量单元实时获取发电机母线电压相量,构建...为提升含高比例电力电子设备的电力系统暂态稳定性,提出一种基于广域测量系统(wide area measurement system,WAMS)的静止无功补偿器(static var compensator,SVC)优化控制策略。通过同步相量测量单元实时获取发电机母线电压相量,构建以发电机电功率与机械功率偏差最小为目标函数的粒子群优化模型,并结合电压幅值与相角灵敏度系数动态计算SVC最优无功功率注入量。创新性引入灵敏度系数刻画发电机有功功率对SVC无功功率的依赖关系,实现多发电机转子角振荡协同阻尼。在DIgSILENT PowerFactory平台搭建IEEE 14节点系统,仿真结果表明,所提策略可有效降低转子角振荡幅度及斜率,使临界清除时间延长40 ms。与传统本地控制方法相比,所提方法突破了单一振荡阻尼限制,利用WAMS信息实现多机协调控制,为提升复杂电力系统暂态稳定性提供了新思路。展开更多
文摘The synchronizing torque of a power system may be weakened by increasing installation of static power converters accompanied by renewable energy resources because they used to trade their favorable active power by synchronizing their output voltage with the one at the point of common coupling. In the circumstances, a concept of Virtual Synchronous Machine (VSM) is proposed, where the self-commutated power converters are emulating synchronous generators. This paper describes a converter control to contribute to enhancing the synchronizing torque. The proposed control is similar to the VSM but it simply realizes active power trades among power generation units including converter-based generators by modulating phase angles of their output voltages. Therefore, it can provide an effective support to regulate the system frequency where the total rated power of the converter-based generators increases as much as the one of conventional rotating generators like a microgrid. This paper especially focuses on its robustness where the number of converter-based generators is increased or they are dispersed in the power network. The effectiveness is verified by simulation study based on instantaneous values.
文摘With the advent of phasor measurement unit (PMU) technology, the grid observability has got a new dimension. This facet of technology helps in getting the real-time and dynamic scenario of the grid operations which was a remote possibility some decades before. Achieving this level of observability puts us at an advantage of responding to the system faults with reduced response time, and helps in restoring the grid stability within fraction of second. This paper demonstrates the detailed fault characterization from the PMU inputs, after illustrations from various real-time examples and different faults occurred in India. This paper tries to shed some light on areas where the accurate fault characterization can help the operator in taking the right decision for reliable grid operations.
文摘远程终端单元(remote terminal unit, RTU)是当前电网中最主要的测量终端,但是其量测量没有统一时标,更新频率低,而且存在不确定性的传输时延。而同步相量测量单元(phasor measurement unit, PMU)具有高同步、高精度等特点,成为电力系统中重要的数据采集装置。为协调利用这两种测量数据,首先归纳出RTU量测非同步的来源,分析了量测数据不同步对状态估计和潮流计算的影响,并给出了相关的验证结果。并提出基于能量交互算子的量测数据相关性分析方法。该方法应用同步数据间相关性最大的原理,利用PMU所产生的精确数据来同步RTU数据,为混合测量系统确定测量基准时刻。通过对IEEE39节点电网和广东83节点实际电网的仿真,结果表明该方法能有效校正量测数据非同步以及改善状态估计和潮流计算精度。
文摘为提升含高比例电力电子设备的电力系统暂态稳定性,提出一种基于广域测量系统(wide area measurement system,WAMS)的静止无功补偿器(static var compensator,SVC)优化控制策略。通过同步相量测量单元实时获取发电机母线电压相量,构建以发电机电功率与机械功率偏差最小为目标函数的粒子群优化模型,并结合电压幅值与相角灵敏度系数动态计算SVC最优无功功率注入量。创新性引入灵敏度系数刻画发电机有功功率对SVC无功功率的依赖关系,实现多发电机转子角振荡协同阻尼。在DIgSILENT PowerFactory平台搭建IEEE 14节点系统,仿真结果表明,所提策略可有效降低转子角振荡幅度及斜率,使临界清除时间延长40 ms。与传统本地控制方法相比,所提方法突破了单一振荡阻尼限制,利用WAMS信息实现多机协调控制,为提升复杂电力系统暂态稳定性提供了新思路。
