What is reverse brake? -Solutions - Huaqiang Electronic Network

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To ensure that the motor speed is reduced to nearly zero, it's important to quickly disconnect the power supply in order to prevent the motor from restarting in the opposite direction. This is why a speed relay is used in the reverse braking circuit. It automatically and promptly cuts off the power when needed. During reverse braking, the relative rotational speed between the rotating magnetic field and the rotor (n1 + n) becomes very high. This causes a large induced current in the rotor winding, which in turn increases the current in the stator winding—often reaching about ten times the motor’s rated current. Because of this high current, reverse braking is typically suitable for small motors with a capacity of 10 kW or less. For motors larger than 4 kW, a current-limiting resistor is usually added to the stator circuit to reduce the braking current and protect the system. Reverse braking offers strong braking force and quick response, making it ideal for applications where rapid stopping is required. However, it also has some disadvantages. The braking accuracy isn't very high, and the process can cause significant mechanical stress, potentially damaging transmission components. Additionally, it consumes a lot of energy and isn't efficient for frequent use. Therefore, reverse braking is commonly used in systems where fast braking is necessary, such as in milling machines and boring machines. These machines often have high inertia and don’t require frequent starting and braking, making reverse braking a practical choice.