大容量空冷同步调相机冷却气体风量分配及优化OA

Large-capacity air-cooled synchronous condensers can provide dynamic reactive power support to the grid and enhance voltage stability during severe voltage faults.However,the high reactive power output also causes a larger temperature rise of the synchronous condensers and further limits their operational capacity.Rational air volume allocation plays a crucial role in reducing the hotspot temperatures of the synchronous condenser.To investigate the impact of air volume allocation on the operational capability of a synchronous condenser,a coupled electromagnetic-fluid-temperature field model of the air-cooled synchronous condenser is established.The temperature distribution patterns under various operating conditions are computed,and an optimized air-volume allocation scheme is proposed. Based on the electromagnetic-fluid-temperature field model,the location of the synchronous condenser's maximum temperature is investigated,and the relationship between air volume allocation and hotspot temperature is analyzed.Using the pilOPT multivariate optimization algorithm,the air volume allocation of the synchronous condenser is optimized to determine the optimal flow allocation scheme.The fluid-flow distribution patterns,stator and rotor temperature distribution patterns,and cooling effectiveness of the cooling system are compared before and after optimization. The results indicate that under different operating conditions of the synchronous condenser,the maximum temperatures stabilize at 99.36℃,79.15℃,72.56℃,and 72.85℃,respectively,under the optimized air volume allocation scheme.The hotspot temperatures are significantly reduced,and the uniformity of the temperature distribution is markedly improved.For Operating Condition 1,the maximum fluid velocity in the synchronous condenser decreases from 107 m/s to 100 m/s,thereby improving fluid uniformity.The temperature in the stator cooling air zone and at the axial edge position decreases significantly.The stator core hotspot temperature drops from 114℃to 96℃,while the stator winding hotspot temperature decreases from 119℃to 99℃.In the rotor region,the hotspot shifts toward the axial center,reducing the hotspot area to one-third of its original size.The core hotspot temperature decreases from 85℃to 77℃,and the maximum temperature of the rotor windings decreases from 85℃to 73℃.The optimized airflow distribution scheme effectively reduces stator and rotor temperatures in the synchronous condenser,thereby significantly improving the cooling efficiency of the cooling system. The conclusions are as follows.(1)Based on the optimized airflow distribution scheme,the maximum flow velocity of the synchronous condenser cooling air is significantly reduced,and the uniformity of the fluid field distribution in the stator and rotor regions is improved.(2)Under four operating conditions,the maximum temperature reduction of the stator core in the synchronous condenser is 18℃,16℃,13℃,and 14℃,while the winding temperature reduction is 20℃,15℃,18℃,and 13℃,demonstrating significant cooling effectiveness.The rotor core and windings exhibit slight temperature reductions under different operating conditions.The cooling effect along the bottom axial direction is pronounced,with a considerable reduction in hotspot regions.(3)After optimization,the standard deviation of the sampling lines for the upper and lower stator windings of the synchronous condenser is vastly reduced,indicating that the uniformity of the temperature distribution is improved while the temperature decreases.