Origin of Motor Testing System
Power supply – for supplying power to the system and the motor under test.
For users, the dynamometer solves the most troublesome problem—loading and data acquisition—but the processing of test results still requires manual intervention. From a demand perspective, this is illustrated in the following diagram:
In reality, motor testing based on dynamometers is still very slow, which led to the development of the next generation of products—motor testing systems.
The self-cultivation of a motor testing system
An ideal motor testing system allows testers to focus solely on the input (setting test environment parameters) to obtain the output (test results and reports) for each test item. Therefore, the dynamometer has undergone a significant upgrade by introducing a PLC and industrial computer, achieving automation of control, loading, and measurement.
At this point, the basic framework of motor testing systems has matured. This type of motor testing system is currently the most widely used, but due to user habits, many still refer to it as a "dynamometer." Such systems can already meet the routine testing needs of most common motors.
The Future of Industrialization and Specialization
The basic framework of current motor testing systems is mature, so where should the next step of development lead? Let's revisit the test object: the motor. The motor family is vast, and as mentioned earlier, different types of motors possess different characteristics, requiring different performance focus points. For example, servo motors focus on control linearity and speed, household appliance motors on efficiency, and electric vehicle motors on power density and high-efficiency range… In the future, motor testing systems will also need to supplement and improve their testing functions to keep pace with different motor industry applications.
As we all know, an electric motor is a fusion of electrical and mechanical components. To evaluate the performance of an electric motor, it is often necessary to comprehensively assess the results of many tests. Generally, from research and development to production, an electric motor needs to go through two stages: type testing (research and development, pilot production, quality inspection) and production testing (factory delivery). Depending on the type of motor and the application industry, there may be more than ten or even dozens of test items (as shown in the figure below).
Given the numerous testing items required for motors, a wide variety of testing instruments and equipment are needed to complete each test. For example, acquiring voltage, current, and power data requires electrical parameter testing equipment; acquiring speed and torque data requires corresponding sensors; during testing, mechanical loads must be added to allow the motor to operate under different conditions; after testing, manual data processing and curve plotting are also necessary… All of this is quite complex and troublesome for testing personnel. Is there a one-time, foolproof testing solution?
The Birth of the Dynamometer
Since there is industry demand, corresponding products will emerge in the market. Testing equipment manufacturers discovered that most motor tests need to be conducted under load, and with the increasing development of embedded technology, communication and control of sensors and instruments are becoming more and more convenient. Therefore, they integrated testing instruments, sensors, and mechanical loading systems—a preliminary testing system, the dynamometer, was born.
A dynamometer has a simple structure, consisting of a cabinet and a test bench, often called a dynamometer head. It typically integrates the torque and speed sensor with the brake. The test bench includes a mounting base, a torque and speed sensor, and a mechanical load (brake). The cabinet includes an electrical parameter tester, a motor tester, a dynamometer controller, and a power supply. The functions of each component are as follows:
Mounting base – used for mounting and securing the motor under test;
Torque-speed sensor – used to acquire the speed and torque of the motor under test;
Mechanical load – generally using brakes, but sometimes using motors – is used to provide reverse rotational torque to the motor under test, absorb the power of the motor under test during operation, realize the “loading” of the motor under test, and simulate its actual operating conditions.
Electrical parameter tester – used for acquiring and displaying electrical parameters such as voltage, current, and power of the tested motor;
Motor tester – used to acquire the output signals of torque and speed sensors and digitally display the speed, torque, and mechanical power of the motor under test;
Dynamometer controller – used to control the output torque of mechanical loads;
