For over 20 years, the author has been engaged in electrical management and technical work, possessing extensive experience in high-voltage electrical control design and automatic control technology application. Currently, he is dedicated to the application of VB and data acquisition technology in motor testing and control, as well as the application of HMI-PLC in motor inspection and control and special motor production equipment. He has successfully developed a motor factory testing system based on VB and data acquisition cards, a motor factory testing platform based on HMI-PLC, and an automatic winding machine based on PLC, which has improved the automation level and efficiency of the company's production equipment.
I previously developed a motor testing system using VB and a data acquisition card. For simplicity and efficiency, I successfully developed a DC motor production line test bench using an HMI and PLC. The system can complete the test with just one start button, providing results such as "pass," "fail," "tooth failure," and "torque adjustment failure," all indicated by different colors. This user-friendly testing process eliminates the need for manual judgment.
System composition:
The PLC uses products from Yung-Hong Company, the HMI uses EVIEW HMI products from Shanghai Boke Company, and the signal conditioning uses products from Beijing Hongtuo Technology. These components are all highly reliable, ensuring the success of the architecture.
The PLC program is structured as follows:
The boot screen generated by HMI programming is shown in Figure 1:
The "Operation and Help" option is a button; clicking it will take you to the help page. Clicking the "VIEW" button below will bring up a quick menu as shown in Figure 2. Clicking the various buttons in Figure 2 will take you to different interfaces.
Figure 1 Startup screen
Figure 3 shows the parameter setting interface. After inputting the data for each range, clicking the parameter confirmation button stores the data in the PLC's D or R register. The PLC program then calls this data for calculation during data processing. After the motor starts, a test is performed. The PLC program collects and calculates the data, displays it on the test interface, and automatically determines whether it is qualified or not. If qualified, the multi-state element at the top of the test interface changes to a blue background with red text indicating "Qualified." No manual judgment is required, and the data is stored on the interface until the next test begins.
Figure 4 Test Interface
PLC Program Analysis: The PLC program ladder diagram is large, so only a portion can be cut out as shown in the following figures. Register D1000 corresponds to the multi-state display element of the pass/fail flag on the test interface. The display corresponding to the D1000 value is shown in the table below. During testing, assigning different values to D1000 based on the judgment result will display different graphics and text. In Figure 5, N001...
The network resets D1000 on the rising edge of X3 when entering the test station, and displays "To be tested" on the HMI. Networks N002 to N005 determine the starter gear if the motor speed is lower than the set value 1.5 seconds after starting, stopping the motor and displaying the gear. In Figure 6, network N011 performs integer-to-floating-point conversion and calculation on the voltage and current range data input from the parameter setting interface. Figure 7 shows the conversion and calculation of set values input from the standard parameter interface, such as voltage and current. Network 8 calls the zero-adjustment program. Since signal conditioning or sensors may produce initial offsets, a zero-adjustment program is needed to sample the initial data and store it in certain registers to ensure accurate data calculations during the test process. Figures 9 and 10 show the sampling and calculation of the no-load current and its display in the no-load current column of the HMI test interface. The algorithm reads data from the PLC analog channel R3841 using the MOV instruction, performs floating-point conversion using the I>F instruction, subtracts the zero-adjustment value using the FSUB instruction, multiplies the current range using the FMUL instruction, and removes the necessary 16383 (the settings vary depending on the PLC) using the FDIV instruction. Finally, the data is sent to the HMI for display. Figures 12 and 13 show the comparison of the test values (voltage, current, torque, and speed under no-load and load) with the standard parameter settings after the test, generating different judgment signals. Figure 12 shows the non-compliance judgment display program, and Figure 13 shows the compliance judgment display program. If any parameter is non-compliant, a value of 3 is sent to D1000, and the test interface displays "non-compliant." Only when all parameters are compliant can a value of 1 be sent to D1000 via network 127, and the test interface displays "compliant."
The Promotion of HMI-PLC Architecture in the Motor Industry: PLCs are highly reliable products, while HMIs have developed rapidly in recent years. Both are relatively inexpensive, easy to configure, and already widely used in many devices. I have developed its application for motor testing for the first time, with good results. Although it's for DC motor testing, it can be extended to factory testing of AC asynchronous motors, achieving equally excellent results. This architecture can also be applied to high-end generator sets and dual-power ATS automatic switching systems, although the cost may be higher, it enhances the product's quality.
Figure 5. Procedure for determining the top tooth and resetting it to be qualified.
Figure 6 shows the program for voltage and current range conversion.
Figure 7 Standard Data Transformation Procedure
Figure 8 Calling the zeroing procedure
Figure 9. No-load current sampling and calculation
Figure 10. No-load voltage sampling and calculation (continued)
Figure 11 Comparison of test sample values and standard parameter settings
Figure 12 Non-conformance marking procedure
Figure 13 Conformity Marking Procedure
