基于电气量特征的水轮发电机电磁转矩分析方法

Electromagnetic torque analysis of large hydrogenerator based on fundamental electric quantity characteristics

为解决大型水轮发电机电磁参数分析困难的现状问题,提出一种基于基波电气量特征的电磁转矩分析方法。通过各相各分支定子线圈的实际连接关系,确定大型水轮发电机稳定运行状态,建立相应稳定运行状态的定子侧三相基波电压、定子侧三相基波电流与电磁功率的数学关系,利用300 MVA大型水轮发电机的有限元模型验证所提方法的有效性。结果表明,基于基波电气量特征的电磁转矩分析方法可准确辨识出大型水轮发电机在稳定运行状态下基波电磁转矩和二次谐波电磁转矩,最大相对误差为10.18%,最小相对误差为0.01%。

This paper proposes an electromagnetic torque analysis method based on fundamental electric quantity to address the difficulty in electromagnetic parameter analysis of large hydrogenerator.The study includes determining the steady running state of large hydro-generator through the actual connected relation of each phase and each branch stator coil;Building up the mathematical relations of three-phase fundamental voltage,three-phase fundamental current and electromagnetic power under the condition of steady running state;and verifying the validity of the proposed method by using the finite element model with a 300 MVA large hydrogenerator.The results show that the electromagnetic torque analysis method based on fundamental electric quantity characteristics can identify the fundamental electromagnetic torque and the second harmonic electromagnetic torque accurately under the condition of steady running state of large hydro-generator stead.The maximum of relative error is 10.18%and the minimum of relative error is 0.01%.