For testing system is often said to test accuracy, can do how many people will ask the system precision, because everyone knows that the precision of the test system is influenced by many factors, is by no means a simple measuring instrument can guarantee accuracy. Today is about torque of motor test system how to ensure accuracy.

In motor test system, torque measurement is often done by torque sensor. Below is a typical way of motor torque test:

Tested motor through a shaft coupling torque sensor, motor load torque sensor through the other end shaft coupling. Measured motor system is working, work in the speed loop (or torque loop), work in torque load motor ring (or the speed ring), torque sensor to measure the torque size and the torque values through the signal is transmitted to the measuring instrument. To understand the torque testing process, we can find the key factor for torque test points, the first: torque sensor measurement accuracy; The second: the measure precision of the instrument; Third: the motor (and load) being measured torque loading precision; Fourth: machinery installation precision of the system. Next we for each factor is analyzed.

The first is the accuracy of measurement of torque sensor. Someone said that the torque sensor is simple, each sensor has a nominal accuracy, check the manual data can know directly. Really no matter domestic or foreign torque sensor, has its nominal accuracy of measurement, but the torque sensor has its measuring range, how to choose the suitable range is also the crucial factor. Here are a "three principles", the so-called "three principles" is when the test torque in 1 n. m within, in order to ensure the accuracy of measurement, suggested measurement range is not less than a third of the range, such as the range of 1 n. m sensor, 0.33 N.m recommended minimum detectable; When measuring the torque in n. 1 m above, in order to ensure the accuracy of measurement, not in the measuring range is less than one 5 of the range, such as the range of 10 n. m sensor, recommended minimum detectable 2 n. m. Only in this way can guarantee the measurement precision of the torque sensor.

Second test instrument measuring accuracy, the traditional motor test system is use the discrete instruments such as electric parameter table, torque of electric parameters and torque speed parameter test to measure, respectively, under the steady state accuracy can guarantee that once the transient parameter measurement will greatly influence the accuracy of measurement. So in transient test cases must be the use of precision measuring instruments, such as the rf power analyzer synchronization measure the electric parameters and torque speed test, keep the accuracy of the measured data.

The third torque loading precision, when we can guarantee the accuracy, loading precision of the system must be considered. Such as system in the process of test, we want to test 5 n. m moment, through the controller to send command, control motor to load, the system must be able to sync monitoring the actual amount of torque, and real-time through the PID adjustment, ensure that the output torque in 5 n. m (error on the large degree of optimization of PID control).

Machinery installation precision of the fourth system, low mechanical installation accuracy, means that the test bench of the angular deviation in the machinery of motor test system in the long run will appear when the deformation, abnormal vibration test bench, such as screw, coupling fracture problem. Therefore must guarantee the accuracy, otherwise everything will be turned into empty before.