A new approach to decrease reserve demand when bulky wind power or UHV is connected

Since wind power is more versatile and unpredictable than traditional thermal power, increasing wind penetration level generally need more spinning reserve, which is not economical. Frequency related voltage control can be helpful to solve this problem. When frequency become lower due to wind farm decreases its output, voltage can be lowered too to decrease active power absorbed by loads. This method can be used together with AGC to restore frequency to normal level. Consequently less spinning reserve is needed. This method can also be used when large generation (like 1000kV UHV line) is lost to avoid load shedding. Simulation also validates the effectiveness of this method.