Hello everyone, I am new to this forum and seeking help. I am currently dealing with a client's program that was created by someone else. The issue I am encountering is that the client has informed me that the VFD (Variable Frequency Drive) is generating a higher torque than necessary, impacting the quality of the materials being produced. The programmer utilized the formula "(Torque Current Feedback/Factor)*100", with the 'factor' value set at 235. The result of this calculation is compared to 105 to trigger a drive run command interlock. This information is displayed on the SCADA system to the operator as "Torque". In essence, the question is, "Why is the 'Torque Current Feedback' value exceeding the desired level?" Can someone provide an explanation?
It is difficult to determine without sufficient information. How is the 755 programmed - for speed, position, or torque control? Is it an axis control or a standard 755 model? What is the 755 system controlling, and what are the load characteristics involved? Additionally, is there an encoder being used in this setup?
Hello Robertmee, the motor at position 755 is currently operating in SVC mode without an encoder to control an Induction Motor. The client's objective is to run the motor at maximum speed while maintaining desired torque levels. However, there is an issue where the torque exceeds the desired value at maximum speed, impacting production speed and the quality of the output material. The client seeks to effectively control the torque at maximum speed to ensure production efficiency and maintain the physical properties of the output material within optimal ranges.
Can you confirm if the motor in question has a Full Load Amperage (FLA) of 235? I am unclear on how Torque Curve Feedback (Torque Cur Fdbk) differs from Output Current in calculating torque percentage. According to the manual, Torque Cur Fdbk represents the current in phase with the voltage and is only a component of the overall output current.
Nauman_95 pointed out that the variable frequency drive (VFD) is generating higher torque than necessary, impacting the quality of the materials being produced. The client's priority is to regulate torque at optimal levels while maintaining production speed and ensuring the physical properties of the output material are within specifications. As a newcomer to this subject, I am curious about how motor torque influences product output at a consistent speed. Would a larger motor operating at a lower torque percentage yield the same results as a smaller motor running at higher torque, or am I mistaken in assuming that the issue is causing a reduction in production speed?
The relationship between speed and torque in a motor is based on its rated power, with torque being necessary to achieve the desired speed depending on the load. It is important to understand that there is no quick fix to reduce torque at maximum speed without adjusting load characteristics. When clients mistake higher torque for causing product variance, it is actually the product characteristics such as weight, tension, and friction that are responsible. By addressing the root cause through process improvements, the torque will naturally stabilize at the appropriate level.
Welcome to the forum! The problem you've described could be due to a wide range of factors. Firstly, you might want to check the calibration of the sensors providing the 'Torque Current Feedback'. Miscalibration could lead to higher readings than what is actually produced. Moreover, the 'factor' in the formula might need to be adjusted. If the factor was determined for a specific case or circumstances and then applied to a different scenario, it might not yield the appropriate 'Torque'. Other things to consider might be the type of load and if any changes have happened there, also age and wear could affect the VFD performance. But without more information, it's hard to pinpoint exactly where things may have gone wrong.
Hey there, welcome to the forum! In the case of the VFD, it's possible that the issue might not originate from the programming side. It could be a mechanical issue or even an issue with the motor itself, perhaps, an issue with the supply voltage, load imbalance or even an aging motor working beyond its designated limit. So, I'd recommend checking these factors first. However, if you believe it's software oriented, you might want to look at how the 'Torque Current Feedback' value is being retrieved and processed. Whether from a sensor or an algorithm, it might be returning values higher than normal due to a fault or miscalculation. Of course, debugging the program will give greater insight. Remember, both hardware and software factors could play into this. Good luck.
It sounds like you've got a unique issue on your hands! One possible reason that the 'Torque Current Feedback' value may be exceeding its desired level is that the function is reading inaccurate or over amplified current levels. Perhaps the drive's current sensors or signaling to the SCADA system is compromised or incorrectly calibrated. Or, the 'factor' value being set to 235 could itself be the issue; maybe it needs adjustment to suit the specific characteristics of the VFD in question. Another probable cause could lie within the mechanical components interacting with the VFD – excessive load, mechanical wear, friction or misalignment could all lead to a higher than needed output torque. Also, environmental variables such as temperature, voltage fluctuations or poor quality of the power supply can influence the performance of a VFD, including its torque. I'd suggest you to start by reviewing these elements and see how you go. If everything checks out, then it might be time to look into potential issues with the program itself.
Welcome to the forum! It sounds like your system might be overcompensating due to an incorrectly set factor value which is causing an increase in torque. You mentioned that the 'factor' is currently set to 235. This value, depending on the specific VFD model, may be too high or too low. It also correlates directly to the torque produced. A lower factor increases the torque and a higher factor reduces it, it's inversely proportional. So, I would suggest verifying the correct default setting for the 'factor' in this calculation from the VFD manufacturer and adjust it accordingly.
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Answer: Answer: The issue of higher torque could be due to factors such as incorrect programming, incorrect calibration of torque sensors, or electrical faults within the system.
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