The increasing penetration of renewable generation presents challenges for system frequency regulation due to short-term power fluctuations and system inertia reductions. This article presents a coordinated control strategy for frequency regulation in which inverter air-conditioning (IAC) units are used to perform primary frequency regulation (PFR) and fixed frequency air-conditioning (FFAC) units are used to perform secondary frequency regulation (SFR). In PFR, the regulation power is provided by adjusting the setpoints of the IAC units. A random number generation method is proposed to stochastically trigger IAC units based on the frequency deviation in real time. Furthermore, a recovery method is presented to stably restore the IAC units to their initial operating states after regulation. In SFR, a constant equivalent duty ratio method is raised to keep the regulation power stable over a long instruction interval. Based on this, the transforming time interval method is presented to determine the ON/OFF status of FFAC units to provide the required regulation power. Additionally, a recovery method for FFAC units is proposed to mitigate the power rebound after regulation. The proposed control strategy achieves an improved frequency regulation effect with fewer communication demands. Dynamic simulations in a six-machine two-area system and an isolated microgrid with wind power verify the effectiveness of the proposed control strategy.

中文翻译：

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用于系统频率调节的空调负荷的协调控制

由于短期功率波动和系统惯性降低，可再生能源发电的普及率不断提高，对系统频率调节提出了挑战。本文提出了一种用于频率调节的协调控制策略，其中变频空调（IAC）单元用于执行一次频率调节（PFR），而固定频率空调（FFAC）单元用于执行二次频率调节（SFR） 。在PFR中，通过调节IAC单元的设定点来提供调节功率。提出了一种基于频率偏差实时随机触发IAC单元的随机数生成方法。此外，提出了一种恢复方法，以在调节后将IAC单元稳定地恢复到其初始运行状态。在SFR中，提出了一种恒定的等效占空比方法，以在较长的指令间隔内保持调节功率稳定。在此基础上，提出了变换时间间隔法来确定FFAC单元的ON / OFF状态，以提供所需的调节功率。另外，提出了一种用于FFAC单元的恢复方法，以减轻调节后的功率回弹。所提出的控制策略以较少的通信需求实现了改进的频率调节效果。在六机两区系统和带有风力的隔离微电网中进行的动态仿真验证了所提出的控制策略的有效性。提出了变换时间间隔法来确定FFAC单元的ON / OFF状态，以提供所需的调节功率。另外，提出了一种用于FFAC单元的恢复方法以减轻调节后的功率回弹。所提出的控制策略以较少的通信需求实现了改进的频率调节效果。在六机两区系统和带有风力的隔离微电网中进行的动态仿真验证了所提出的控制策略的有效性。提出了变换时间间隔法来确定FFAC单元的ON / OFF状态，以提供所需的调节功率。另外，提出了一种用于FFAC单元的恢复方法以减轻调节后的功率回弹。所提出的控制策略以较少的通信需求实现了改进的频率调节效果。在六机两区系统和带有风力的隔离微电网中进行的动态仿真验证了所提出的控制策略的有效性。