Hey there! As a supplier of 18.5KW VFDs (Variable Frequency Drives), I often get asked about how to use the braking function of these drives. Today, I'm gonna break it down for you in a simple and easy - to - understand way.
First off, let's talk about why you need the braking function in a 18.5KW VFD. In many industrial applications, motors need to stop quickly and precisely. For example, in conveyor systems, when there's an emergency or the end of a cycle, you want the conveyor to stop right away. That's where the braking function of the VFD comes in handy. It helps dissipate the energy generated by the motor during the deceleration process, allowing for a faster and more controlled stop.
Types of Braking in VFDs
There are mainly two types of braking that you can use with a 18.5KW VFD: dynamic braking and regenerative braking.
Dynamic Braking
Dynamic braking is the more common method. When the motor is decelerating, it acts as a generator and produces electrical energy. In dynamic braking, this energy is dissipated as heat through a braking resistor. The VFD detects the excess energy and redirects it to the braking resistor.
To use dynamic braking with your 18.5KW VFD, you first need to select the right braking resistor. The resistor's power rating and resistance value are crucial. You can usually find guidelines in the VFD's manual on how to choose the appropriate resistor based on the motor's power and the application requirements. Once you've installed the braking resistor correctly, you'll need to configure the VFD settings.
In the VFD's parameter settings, you'll find options related to braking. You need to set the braking torque and the braking time. The braking torque determines how quickly the motor will stop. A higher braking torque will result in a faster stop, but it also means more energy will be dissipated in the resistor, so you need to make sure the resistor can handle it. The braking time is the duration over which the braking will occur. You can adjust these settings according to your specific application needs.
Regenerative Braking
Regenerative braking is a bit more advanced. Instead of dissipating the energy as heat, it feeds the excess energy back into the power supply system. This is not only more energy - efficient but also better for the environment. However, it requires additional equipment, such as a regenerative unit.
To use regenerative braking with your 18.5KW VFD, you'll need to install a regenerative unit between the VFD and the power supply. The regenerative unit converts the DC voltage from the VFD into AC voltage that can be fed back into the grid. After installation, you'll need to configure the VFD and the regenerative unit to work together. This involves setting parameters like the feedback power limit and the voltage at which the energy will be fed back.
Safety Considerations
When using the braking function of your 18.5KW VFD, safety is of utmost importance. If you're using dynamic braking, the braking resistor can get very hot. Make sure it's installed in a well - ventilated area and away from flammable materials. You should also use proper insulation to prevent any electrical hazards.
For regenerative braking, since you're feeding energy back into the power supply, there are potential issues with power quality and grid compatibility. You need to ensure that the regenerative unit is properly rated and that it meets all the relevant electrical standards.
Common Mistakes to Avoid
One common mistake is choosing the wrong braking resistor for dynamic braking. If the resistor's power rating is too low, it can overheat and even burn out. On the other hand, if it's too high, it may not be effective in dissipating the energy. Always double - check the resistor's specifications before installation.
Another mistake is incorrect parameter setting in the VFD. If the braking torque is set too high, it can cause mechanical stress on the motor and the connected equipment. If it's set too low, the motor may not stop quickly enough. Take the time to understand the application requirements and adjust the parameters accordingly.
Related Products
If you're not sure if a 18.5KW VFD is the right fit for your application, we also offer 5.5KW VFD and 7.5KW VFD. These smaller - capacity VFDs can be a great option for less power - hungry applications. And if you're dealing with single - phase power sources and need to drive a three - phase motor, our VFD Single Phase To 3 Phase is the perfect solution.
Conclusion
Using the braking function of a 18.5KW VFD can greatly improve the performance and safety of your motor - driven applications. Whether you choose dynamic braking or regenerative braking, make sure you understand the principles and follow the correct procedures. If you have any questions or need further assistance, don't hesitate to reach out. We're here to help you make the most of your VFD. If you're interested in purchasing our 18.5KW VFDs or other related products, feel free to contact us for a detailed quote and to discuss your specific requirements.
References
- VFD User Manuals
- Electrical Engineering Textbooks on Motor Control