基于LM算法的集群电机系统能耗评估校正模型

为了保证和提高电机系统能耗模型的计算精度与评估能力,该文提出了一种基于参数辨识理论的集群电机系统能耗校正方法。采用列文伯格-马夸尔特(levenberg-marquardt algorithm,LM)算法,对单台电机和集群电机系统的额定效率、额定可变损耗及不变损耗参数进行辨识,建立了电机能耗计算的校正模型。在此基础上,以典型三机集群电机系统为算例,搭建真实物理试验平台,对集群电机系统进行全域负载率能耗计算。结果表明,该文提出的能耗校正模型的计算误差远远小于能耗出厂模型(误差率不到1%),可以大幅降低集群电机系统的能耗计算误差,工程实用性较强,为电机用能系统的能耗评估和节能改造提供了一种有效的技术手段。

Correction model of energy consumption evaluation of cluster motor system based on levenberg-marquardt algorithm

Abstract: China is a large agricultural country. Motor is the main energy consuming equipment in agricultural production. With the continuous growth of global energy consumption, environmental and energy problems are becoming increasingly prominent. Energy-saving of motor systems has become the focus of attention in China. There are 3 main methods for calculating the conventional energy consumption of motor systems. One is to calculate the energy consumption of the system in real time by monitoring the input and output data of the motor. However, this method is limited to monitor the current energy consumption level and cannot analyze the energy consumption under the global load rate. The other is to construct the energy consumption model of the system based on the nameplate of the motor manufacturer and calculate the energy consumption with the measurable data. However, with the increase of the use time of the motor and the improper maintenance, or because of the influence of temperature, humidity and aging of the motor on the running state of the motor, the real value of the energy consumption parameters in the energy consumption model often cannot reach the initial value. The initial value leads to large calculation error. The last one is to build motor loss model by measuring and calculating iron loss, copper loss, mechanical loss and stray loss, and then analyze its energy consumption. However, this method requires high data measurement ability and complex calculation, and even requires shutdown operation, which is not practical in application.The aim of this study was to propose an energy consumption correction method for cluster motor system based on the parameter identification theory to ensure and increase the calculation accuracy and evaluation capability of the energy consumption model. The levenberg-marquardt (LM) algorithmwas used to recognize the rated efficiency, rated variable loss and constant loss parameters of a single motor and cluster motor system, then a calibration model for energy consumption calculation of the motor based on recognized parameters was constructed to achieve correction of system energy consumption model. Based on the above theory, a typical three-motor cluster motor system was set up as a physical experiment platform sample to acquire real operating data, which included rated voltage UN=220 V, rated current IN=0.5 A, rated frequency fN=50 Hz, rated power PN=1 000 W, as well as rated rotor speed nN=1 420 r/min. The results showed that the calibration energy consumption model of this study can dramatically decrease the error of energy consumption calculation of cluster motor system and have strong engineering practicability, and it provided an effective technical approach for energy evaluation and energy saving modification of motor energy consumption system.