一种适用于线路两侧电势幅值不相等的实时功角计算方法

功角实时计算通常应用于电力系统稳定分析与振荡识别，但是现有的线路功角计算方法在两侧电势幅值不相等时存在较大误差，为此提出了一种新的实时功角计算方法。针对计算电压最低点位于电势连线内、外两种情况进行讨论，得到不同状态下的功角计算公式，并对两种功角计算公式进行判别。考虑到以稳态母线电压来近似电势幅值，会给功角计算带来一定误差，为此对电势幅值进行修正，并将修正后的功角计算误差与现有方法的误差进行对比。基于PSCAD的仿真验证证明了新方法的可靠性和有效性。结果表明，相比于现有功角计算方法而言，新方法有效降低了两侧电势幅值不相等时功角计算的误差，具有良好的计算精度和实用效果。

A real-time power angle calculation method suitable for unequal potential amplitudes on both sides of the line

Real-time calculation of power angle is usually used in power system stability analysis and oscillation identification, but the existing line power angle calculation method has a large error when the potential amplitudes on both sides are not equal. For this reason, a new real-time power angle calculation method is proposed. Two situations where the lowest point of the calculated voltage is located inside and outside the potential connection are discussed, and the power angle calculation formulas under different conditions are obtained and distinguished. The steady-state bus voltage is used to approximate the potential amplitude. This will bring a certain error to the power angle calculation. Therefore, the potential amplitude is corrected and the corrected power angle calculation error is compared with the error of the existing method. Simulation verifications based on PSCAD prove the reliability and effectiveness of the new method. The results show that compared with the existing power angle calculation method, the new method effectively reduces the power angle calculation error when the potential amplitudes on both sides are not equal and has good calculation accuracy and practical effect. This work is supported by the National Key Research and Development Program of China (No. 2021YFB2401000).