In the universal inverter, the new technology of "dynamic braking" will be truly
Posted by sere on March 13th, 2020
In a traditional frequency conversion speed regulation system consisting of a general-purpose inverter, an asynchronous motor, and a mechanical load, when the potential energy load transmitted by the motor is lowered, the motor may be in a regenerative braking state; or when the motor moves from high speed to low speed (including (Stop) When decelerating, the frequency can be abruptly reduced. However, due to the mechanical inertia of the motor, the motor may also be in a regenerative power generation state. The mechanical energy stored in the transmission system is converted into electrical energy by the motor and sent back to the inverter through six freewheeling diodes In the DC link of the frequency converter. The inverter at this time is in a rectified state. At this time, if no energy consumption measures are taken in the inverter, this part of the energy will cause the voltage of the energy storage capacitor in the intermediate circuit to rise. If the brake is too fast or the mechanical load is a hoist, this part of energy may cause damage to the inverter, so we should seriously consider this part of energy.
In general-purpose frequency converters, there are two most commonly used treatment methods for regenerative energy:
1. Dissipated into the "braking resistor" which is set in the DC circuit and connected in parallel with the capacitor, which is called dynamic braking state;
2. If it is fed back to the grid, it is called the feedback braking state (also called regenerative braking state). There is also a braking method, namely DC braking, which is used in situations that require accurate stopping or irregular rotation of the brake motor due to external factors before starting.
In books and publications, many experts have talked about the design and application of inverter braking, especially in recent times there have been many articles on "energy feedback braking". Today, the author provides a new type of braking method, which has the advantages of four-quadrant operation of "feedback braking" and high operating efficiency. It also has the advantages of "dynamic braking" without pollution to the power grid and high reliability.
With the widening of the application area of general-purpose inverters, the application technology of inverter braking will have great development prospects. Specifically, hanging cages (carrying or loading), inclined mine cars (single Tube or double tube), lifting machinery and other industries. In short, all occasions that require energy feedback devices can be used.
□ Escalator □ Cable Machinery □ Printing and Dyeing Equipment □ Chemical Machinery □ Plastic Machinery □ Oil Field Equipment □ Mining Machinery Equipment
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About the Authorsere
Joined: June 6th, 2019
Articles Posted: 740
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