Transient voltage stability control of 110kV oilfield power grid under power flow disturbance caused by high proportion of new energy grid connection

Abstract

A fixed-proportion load shedding scheme with fixed-parameter reactive power compensation can barely maintain voltage under weak disturbances. Once the output of new energy sources fluctuates drastically, the adaptive matching control strategy cannot be implemented, resulting in poor transient voltage control stability of the 110 kV oilfield power grid. Therefore, this paper proposes a transient voltage stability control method for the 110 kV oilfield power grid under power flow disturbance caused by a high proportion of new energy grid connection. Based on synchronous phasor measurement technology and an improved state equation, combined with a Kalman filter algorithm, the transient voltage changes of the oilfield power grid are accurately and in real time sensed. By constructing a coupled model of new energy output, power flow propagation, and voltage frequency response, the grid operation risk is quantified and classified into three risk levels. Finally, combined with the oilfield load characteristics, the priority of the three load control levels is distinguished. A graded load shedding strategy adapted to the risk level is adopted, combined with SVG adaptive dynamic reactive power compensation optimization control. Through active and reactive power coordinated control, the grid disturbance caused by new energy grid connection is quickly mitigated, achieving transient voltage stability control of the 110 kV oilfield power grid. Experiments show that the research method controls the transient voltage deviation of the 110 kV oilfield power grid nodes within 1.7 kV throughout the entire process under the power flow disturbance caused by a high proportion of renewable energy grid connection. Compared with the voltage deviation of 8.46 kV in Comparison Method 1, 4.12 kV in Comparison Method 2, and 1.82 kV in Comparison Method 3, the method reduces the deviation by 79.9%, 58.7%, and 6.6%, respectively. The absolute node transient voltage deviation is 1.7 kV for the proposed method, 8.46 kV for Comparison Method 1, 4.12 kV for Comparison Method 2, and 1.82 kV for Comparison Method 3. Simultaneously, it maintains the transient stability margin within a high safety range of 85%–92%, an improvement of 50 percentage points compared to Comparison Method 1, effectively improving the transient voltage stability control performance of the 110 kV oilfield power grid.