中文摘要：

为降低数控机床空载运行时的功率损失，建立基于频率的数控机床主传动系统的空载能量参数模型，在此基础上对机床空载运行下的能量参数特性进行了分析，其中能量参数包括空载功率、空载电流和功率因数。主传动系统空载功率的分析结果表明，当电源频率小于基准频率时空载功率是单调递增的，电源频率大于基准频率主传动系统的空载功率的增减性与其结构参数有关，并给出了存在最小空载功率的充分条件；空载电流的分析结果表明，电流在基准频率以下是单调递增的，基准频率以上是单调递减的；功率因数的分析结果表明，其变化无论在基准频率以下还是以上都依赖于主传动系统结构参数。对一台5坐标数控机床进行实验研究，实验结果表明了能量参数特性分析的有效性。

英文摘要：

To reduce the power loss of Computerized Numerical Control （CNC） machine tool during no-load operation, a no-load energy-parameter model of CNC machine tool main transmission system was proposed based on frequency turned by Variable Voltage and Variable Frequency （VVVF）. On these basis, the characteristics of no-load energy parameters under no-load operation were analyzed, which included no-load power, no-load current and power factor. The analysis result on the tare power showed that when power supply frequency was less than the base frequency, the tare power increased monotonically with the increase of power supply frequency, whereas when power supply frequency was more than the base frequency, the monotonicity of tare power depended on the parameters of main transmission system. In addition, a sufficient condition was presented for determining whether the minimum of tare power existed or not when the power supply frequency was greater than the base frequency. Furthermore, the analysis result on the no-load current showed that the no-load current increased when the power supply frequency was less than the base frequency and decreased when the supply frequency was greater than the base frequency, and the monotonicity of power factor was parameter-dependent within the whole range of the power supply frequency. The experiments were conducted on a 5-axis CNC machine tool and the result demonstrated the effectiveness of the characteristics of no-load energy parameters.