A quasi-linear relationship between voltage angles and voltage magnitudes in power flow calculation is presented. An accurate estimation of voltage magnitudes can be provided by the quasi-linear relationship when voltage angles are derived by classical DC power flow. Based on the quasi-linear relationship, a novel extended DC power flow (EDCPF) model is proposed considering voltage magnitudes. It is simple, reliable and accurate for both distribution network and transmission network in normal system operation states. The accuracy of ED-CPF model is verified through a series of standard test systems.

中文翻译：

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考虑电压幅度的扩展直流潮流模型

提出了潮流计算中电压角与电压幅值之间的准线性关系。当电压角由经典的直流潮流导出时，可以通过准线性关系来准确估算电压大小。基于准线性关系，提出了一种考虑电压幅度的新型扩展直流潮流（EDCPF）模型。在正常的系统运行状态下，它对于配电网和传输网都是简单，可靠和准确的。ED-CPF模型的准确性通过一系列标准测试系统进行了验证。