同步电动机节能是电动机节能的一个重要组成部分。同步电动机因其转速恒定，功率因数可调被广泛应用。同步电动机励磁系统的调节一般为开环手动调节，在负载变化的情况下，控制器不能实现闭环跟踪控制，浪费大量的电能，因此研究新型同步电动机节能控制器十分必要。 首先，本文从同步电动机不同负载时效率较低的原因出发，分析同步电动机的能耗关系，同时对调节功率因数节能的可行性和晶闸管触发角的变化对定子电枢电流的影响进行了研究。其次，采用PID控制器来控制晶闸管触发角，实现同步电动机不同负载时的节能自动控制。最后，选用DSPTMS320F2812为节能控制器的控制核心，设计同步电动机节能控制器的软硬件，搭建同步电动机的实验平台，对同步电动机节能控制器的各模块及整体进行了测试，并对不同负载条件下的测试结果进行分析。 实验结果表明：本文设计的同步电动机节能控制器硬、软件配合良好，响应速度快，控制精度高，实验结果正确，达到了预期的设计目标。

Saving energy for synchronous motor is an important component of saving energy for motor. The synchronous motor is used widely because of the constant speed and adjustable power factor. The adjustment method of the excitation system of synchronous motor is open-loop manual adjustment. When the load changed， the current controller cannot implement closed-loop control to save power energy. Therefore， it is necessary to research new synchronous motor controller to economize energy. First of all， this dissertation starts from the reason for synchronous motor in low efficient with different loads， analyzing the relationship of energy consumption and researches the feasibility of saving energy by adjusting power factor and the influence of stator armature current control by changing the firing angle. Secondly， PID controller is applied to control the firing angle of SCR， in order to realize energy saving control for synchronous motor in different loads. Thirdly， DSPTMS320F2812， developed by TI Company in USA， is adopted as the processing core of the controller. After software and hardware of controller designed， and the experiment platform established， I tested all the modules and the whole controller， and analyzed the test results in different loads. The results of experiment indicate that the designed energy-saving controller for synchronous motor performs excellently in software and hardware， responses quickly， and operates accurately. The research can be testified correctly and the prospective goal achieved successfully.