This paper introduces an online testing method using a servo drive as the test platform: using a servo drive as the feed test platform, adjustable simulated load and no-load test platforms, and using a test platform with a motor, a test platform with inherent load running motor, and a test platform.
1. Servo Driver Inter-Drive Test Platform
This system includes a three-phase PWM rectifier, a test servo drive system, a load servo drive system, and a computer control system. The test motor is in electrical operation mode, while the load motor is in production mode. The system uses a speed closed-loop method to control the speed of the entire test platform. The load servo motor system operates in a torque closed-loop mode, simulating changes in motor load by altering the load motor's torque through changes in its current. This allows for flexible adjustment of the traction test platform's speed and torque, enabling testing of various functions.
The host computer monitors the entire system in real time. It controls the two servo drives according to testing needs, and acquires, analyzes, and displays their data. Controlling the speed and torque of the motor and load device allows for dynamic and static simulations under different load conditions, accurately testing the dynamic characteristics of the servo drive. However, due to the use of two different servo-motor control methods, this measurement system is quite large and cannot meet portable requirements.
2. Adjustable Simulated Load Test Platform
This system comprises three main modules: a test servo drive system, a simulated load adjustment system, and a computer control system. Adjustable simulated loads, such as magnetic powder brakes and power dynamometers, are coaxially connected to the machine under test. The host computer and data acquisition card control the adjustable simulated load and acquire, analyze, and display data from the servo system. This test system can also simulate the dynamic and static performance of the servo drive under different load conditions using the adjustable simulated load to achieve accurate testing. However, this test system is still quite large, failing to meet portable requirements, and the measurement and control circuitry is relatively complex and expensive.
3. Test Platform with Actuator Motor and No-Load Function
Servo drives fall into two main categories: servo drive motors and computers. The host computer transmits speed command signals to the servo drive, which then starts according to the instructions. During operation, the computer and data acquisition circuitry complete the data acquisition, storage, analysis, and display of the servo system. Because this test system uses a no-load motor, its size is smaller than the previous two test systems, and its measurement and control circuit is also simpler. However, this system cannot fully simulate actual servo drives. Typically, this test system only detects the speed and angular displacement of the system under test under no-load conditions, and cannot perform precise detection.
4. The intrinsic load of the test platform is driven by the actuator.
This system consists of three main components: a servo drive motor system, the system's inherent load, and a computer. The host computer transmits speed command signals to the servo drive, and the servo system starts working according to the commands. During operation, the computer and data acquisition circuit complete the data acquisition, storage, analysis, and display of the servo system.
In this experiment, the load is the inherent load of the system under test. Therefore, the measurement process is similar to the actual working conditions of the servo drive, and the measurement results are accurate. However, because some loads of the system under test are difficult to remove from the device, the test process can only be carried out on the device, which is inconvenient.