The increasing number of weak-grid-connected renewable energy resources in power systems has created various challenges in recent years. Some examples include un-damped voltage oscillations in the ERCOT and sub-synchronous resonance in the North-China power grid. Several solutions for these challenges have been proposed, such as Static Compensators and Synchronous Condensers (SynCons). SynCons, being synchronous machines without a prime mover, provide several benefits in weak power systems, such as frequency support, system strength, and voltage regulation. Although SynCons are widely-utilized to mitigate the weak grid integration challenges, their installation /operation costs make them a costly solution. Additionally, their lead-time can be more than a year, which means their initial sizing and allocation must be optimal. In this paper, a method for the optimal allocation and sizing of SynCons is proposed. The main objective of this method is maintaining Short Circuit Ratio (SCR) in the system greater than pre-defined values while the investment and operation costs of SynCons, and voltage deviation in the system are minimized. Three meta-heuristic optimization algorithms are used to implement the proposed method, and its performance is evaluated via Electromagnetic Transient (EMT) time-domain simulation in a modified IEEE 39-bus system. The PSCAD/EMTDC software is used for the time-domain simulation. The simulation results confirm that with optimized allocation and sizing, the SCR of the network in all areas is more than pre-defined values, and also, all renewable energy resources can ride through disturbances and comply with given grid codes.

中文翻译：

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风力发电场和太阳能发电场渗透率增加的弱电网中同步冷凝器的最优分配和尺寸确定

近年来，电力系统中连接弱电网的可再生能源越来越多，这带来了各种挑战。一些示例包括ERCOT中的无阻尼电压振荡和华北电网中的次同步谐振。已经提出了针对这些挑战的几种解决方案，例如静态补偿器和同步电容器（SynCons）。作为没有原动机的同步电机，SynCons在弱电系统中具有多项优势，例如频率支持，系统强度和电压调节。尽管SynCons广泛用于缓解薄弱的电网集成挑战，但其安装/运行成本使它们成为昂贵的解决方案。此外，它们的交货时间可能超过一年，这意味着它们的初始大小和分配必须是最佳的。在本文中，提出了一种优化SynCons分配和大小的方法。该方法的主要目的是使系统中的短路比（SCR）大于预定值，同时使SynCons的投资和运营成本以及系统中的电压偏差最小化。使用三种元启发式优化算法来实现该方法，并在改进的IEEE 39总线系统中通过电磁暂态（EMT）时域仿真来评估其性能。PSCAD / EMTDC软件用于时域仿真。仿真结果证实，通过优化分配和规模调整，所有区域的网络SCR都将超过预定值，并且所有可再生能源都可以渡过干扰并符合给定的电网规范。