1.School of Electrical Engineering, Southwest Jiaotong University, Chengdu 610031, China;2.New Smart City High-quality Power Supply Joint Laboratory of China Southern Power Grid (Shenzhen Power Supply Co., Ltd.), Shenzhen 518020, China

With the rapid development of power system, its scale is getting larger and the number of nodes is increasing. As the two most widely used harmonic resonance analysis methods, the frequency scanning method and modal analysis method urgently need to be improved on the computational efficiency. Based on traditional methods, the frequency scanning method based on the adaptive step size and the modal analysis method based on the adaptive step size are proposed, respectively. First, by setting corresponding criteria to adaptively change the scanning step size, the scanning interval can quickly reach the vicinity of the resonant frequency point, thus greatly reducing the computational cost. Then, the quadratic interpolation method is used near the resonant frequency point to determine the resonant frequency, thus guaranteeing the calculation accuracy of the resonant frequency. Finally, the IEEE 14-bus, IEEE 39-bus and IEEE118-bus systems are taken as examples for analysis. The results show that compared with traditional methods, the proposed two methods can greatly improve the calculation speed while ensuring the accuracy of the resonant frequency, verifying the accuracy and efficiency of the proposed methods.

This work is supported by China Southern Power Grid Company Limited (No. 090000KK52220014/SZKJXM20220021).