Improving the Capability of Interconnected Grid Based on AC Modulation Method

This paper proposes a method based on AC modulation to improve transmission capacity of wide-area interconnected power system. The power flow of the important transmission channel was regarded as the modulation signal and sent to the AVR (Auto Voltage Regulator) of the main generator in the power system. Using the rapid regulation of AVR, the AC modulation method could inhibit voltage reduction of the transmission channel´s hub substation, hence the transmission capacity was improved. Furthermore, it used the PSASP to design a controller of AC and the key parameters of the controller were optimized and coordinated according to EHV (extra-high voltage) power system in China. Then, it made the proposed method to EPRI-7 and a practical engineering power gird. At last, based on the weakness of the research power grid, it compared the effects with the other engineering methods. Finally, the robustness of the proposed method was tested. The results for some examples show that the method for improving the transmission capacity is effective and applicable in engineering.