How Dc Injection Provides Controlled Braking?

By Author: Chris Holmes
Total Articles: 4
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With DC injection you can adjust the braking rate to a specific requirement. It is commonly used on three-phase AC windings. The injected DC produces a pulsating torque motion bringing the circuit to stop. The braking system is effectively used in industrial operations.

DC injection is an efficient method for providing controlled braking for AC electric motors. It satisfies the reliability requirements for industrial machines. Breaking operation is rapid, helping in increasing the production rates, yet adhering to the safety norms.

The halting system works by the sudden input of a direct current into an alternating current system, causing the machine to slow down and stop. The braking system is effectively used in industrial operations and vehicles such as centrifuges, chippers, conveyor systems, rock crushers, circular saws, shredders, grinders, fans, band saws, etc.

Another advantage of DC injection is that you can adjust the braking rate to a specific requirement. This is achieved by injecting a closed loop current control. It is most commonly used on three-phase AC windings. A direct current volt is ...
... injected into the circuit while the rotor is still in motion. This produces a pulsating torque motion bringing the entire circuit to stop. In variable speed drives, engineers may prefer to build a power transistor circuit making a dynamic braking system.

Plugging is another braking technique used with AC drives. The mechanism reverses the power supplied to the electric motor. Plugging causes the machine to stop though the operation is not as smooth or controlled as the DC injection process.

Engineers usually prefer DC injection as it is smoother and more efficient. It causes less stress and friction to the system, making the entire drive more durable and resistant to damage.

It is important to make sure that the braking system you choose complies with the relevant safety standards. Such a system will pose no safety risk during breaking or normal operations. DC injection electric motor systems used in industrial machines often features an integrated starting system offering several safety and functional advantages. DC Injection braking systems can manipulate systems running at high speeds with heavy loads effectively. It is achieved easily and reliably, making it the preferred braking system for several industrial operations.

DC Injection technique can also be used for preheating the motor and ensuring that water vapor does not condense in the motor windings. However, it needs to be taken into account that DC current applied across a winding acts like a short circuit. The mechanism must make sure that the current is limited and the time limit is set.

A small amount of DC injection may saturate the core of magnetic circuits in rotating electrical machines and transformers. Uncontrolled injection may result in some pulsating torque and overheating. Interference in measurement transducers may also appear.

DC injection is the standard feature of AC motor drives today. In case the DC injection is not injected, the motor would slow on the removal of feed, but would take a long time to stop that may not be admissible in emergency conditions. As there is no need for touching the parts, mechanical maintenance is also minimal.

Synchronous wind turbine generators are one of the many examples of DC injection break. When consistent quick winds put wind turbines under great stress, the rate of rotation of the propellers may damage the turbine structure. Injection of DC electric brake slows the rotation of the propeller.

Author of this article is associated with ICP (Industrial Clutch Parts) that deals in a broad range of products including electric brake, centrifugal clutch, fluid couplings, friction materials and other such products.