【作者】 范杰；

【导师】 王明渝；

【作者基本信息】 重庆大学 ， 电气工程， 2007， 硕士

【摘要】 测功机是电机性能测试台、机械传动测试台、以及发动机性能测试台等试验装置中的核心设备。传统的测功机,比如磁滞测功机、电涡流测功机、机械测功机、水力测功机均是将测试中所产生的能量转化为热能而消耗掉,不仅造成能量浪费,而且还需配置散热设备。电力测功机运行时相当于一台发电机,可以将原动机输入的机械能转化为电能回馈到电网,这是其它类型测功机所不具备的。本文在直接转矩控制理论的基础上提出了一种新型的电力测功机:它采用永磁同步电机作为测功电机,可以实现负载转矩的估算,因此测试过程不需要转矩传感器,降低了系统的硬件成本;通过使用公共直流母线技术,被测电机从电网吸收能量带动测功电机旋转,测功电机通过逆变器将能量回馈到直流母线,提供给被测电机,实现了能量的循环利用,既节约了电能,又提高了测量范围。目前国内多数测功机被用于静态加载实验,通过测量转矩-转速特性曲线、功率损耗、效率等对原动机的性能进行评估。对于电机调速系统的测试,静态加载并不能满足要求。因为动态和非线性因素对一些负载的影响是很重要的,所以用于调速系统测试的测功机应该能够进行动态测试。本文所研究的便是一种动态测功机方案,不仅可以进行静态加载,还可以使输出转矩随转速而改变,实现动态加载。本文首先在直接转矩控制理论的基础上对测功电机的控制系统进行了仿真研究,然后用这个控制系统搭建了测功机系统的模型并进行了仿真:仿真过程分为静态和动态两部分,分别研究测功机静态和动态加载的能力。仿真结果表明测功机系统在两种情况下都能实时跟踪给定转矩的变化,所以这是一种可行的方案。在确定了理论上的可行性后,开始搭建系统实验平台。采用TI公司的DSP芯片TMS320LF2407作为处理器,对富士公司的IPM模块7MBP50RA120进行控制,驱动永磁同步电机。最后对硬件驱动电路进行了实验,结果表明所设计的驱动电路可以输出给定频率的驱动信号。更多还原

【Abstract】 The dynamometer is core equipment of motor performance test station, mechanical drive test station and engine performance test station. Traditional dynamometers, such as hysteretic dynamometers, eddy current dynamometers, mechanic dynamometers and waterpower dynamometers, may consume lots of fuels and electrical energy while working, which causes the energy waste. Also, these dynamometers should be equipped with additional radiators to keep the dynamometers cool. Electrical dynamometer works as a generator when operating, which can convert mechanical energy to electrical energy and feed it back to the AC networks, the others do not have this function. A type of novel electrical dynamometer based on direct torque control (DTC) is presented in this dissertation. A permanent magnet synchronous motor (PMSM) is used and the load torque is estimated so as to eliminate the torque transducer which can reduce the hardware cost. The motor under test receive power from AC network and drive the load machine which feed back the energy to the DC-bus by an inverter. The common DC bus technology which achieves the circular use of power can not only save the energy cost but also improve the testing range.Mostly, dynamometers have been used to perform static load tests. The performance is then evaluated by measuring the torque-speed characteristic, power losses, efficiency, etc. For testing variable speed electric drives, static load tests are not sufficient, because dynamic or non-linear effects in some loads can be dominant. Therefore a dynamometer for testing of drives should be able to perform dynamical tests. The dynamometer presented by this dissertation can not only used for static load test but also make the load torque change with the shaft velocity in order to be used for dynamic load test. Firstly, a variable speed drive system based on DTC is simulated, then a simulation model of dynamometer is established. The simulation consists of two parts: dynamic test and static test. The result shows that the system can track the changing torque reference, so this is a feasible strategy.After the feasible research a experimental platform is established. Use digital signal processor (DSP) TMS320LF2407 as CPU, to control IPM 7MBP50RA120 which drive the PMSM. At last, an experiment is done to check the drive circuit. The result shows that the drive board works well and can output the needed drive signal.更多还原