What is a Soft Launch?

The soft starter uses three opposite parallel thyristors as voltage regulators. Using such a circuit as a three-phase full-control bridge rectifier circuit, when a soft starter is used to start the motor, the output voltage of the thyristor gradually increases, and the motor gradually accelerates until the thyristor is fully conducting. On, the motor works on the mechanical characteristics of the rated voltage to achieve smooth start, reduce the starting current, avoid starting overcurrent trip, and connect it between the power supply and the motor stator.

Soft start

The soft starter uses three opposite parallel thyristors as voltage regulators. Using such a circuit as a three-phase full-control bridge rectifier circuit, when a soft starter is used to start the motor, the output voltage of the thyristor gradually increases, and the motor gradually accelerates until the thyristor is fully conducting. On, the motor works on the mechanical characteristics of the rated voltage to achieve smooth start, reduce the starting current, avoid starting overcurrent trip, and connect it between the power supply and the motor stator.

Chinese name

Soft start

Foreign name

soft starter

Function

Regulator

The voltage is gradually increased from zero to the rated voltage. In this way, the starting current of the motor during the starting process is changed from uncontrollable overload surge current to controllable. And you can adjust the size of the starting current as needed. There is no shock torque during the whole process of motor starting, but smooth starting operation. This is soft start. ^[1]

A soft starter is a set

Soft start generally has the following starting methods:

(1) Soft start for ramp boost;

(2) Constant-current ramp soft start;

(3) Step start;

(4)

Soft starter using

At present, China's economy has entered a new stage of development, more and more large enterprises and large equipment, more and more applications of large motors (5000kW ~ 60,000kW), and the starting methods of large motors have become more and more important.

There are stages in social development. At different stages, people's production methods, production tools and daily necessities are very different. In the 1980s and 1990s, China's economic strength was still weak. At that time, small cement and steel developed rapidly. The application of 1000kW to 4000kW motors grew rapidly. Liquid starters that were compatible with the economic foundation of the time appeared. It is economical and practical and solves some problems in motor starting. It played a certain role in the economic development at that time. By the turn of the century, China's economic strength had developed greatly, production methods and tools had also developed greatly, and motor capacity had also increased greatly. People began to dissatisfy the low performance of liquid starters, so thyristors were connected in series. The application of solid-state (solid-state) soft-start devices has begun to increase, and then there have been switching transformer-type soft-start devices and magnetic saturation.

HPS2D conventional soft starter

Energy-saving operation mode: reducing the voltage at light load reduces the exciting current, and the motor current is divided into active and reactive components (excitation component) to improve COS.

Energy-saving operation mode: When the motor is lightly loaded, the soft starter is in the state of selecting the energy-saving function, and the PF switch is hot dialed to the Y position. Under the action of current feedback, the soft starter automatically reduces the motor voltage. Reduced motor current

Usually pay attention to check the environmental conditions of the soft start to prevent operation in excess of its allowed environmental conditions. Pay attention to check whether there is any object around the soft starter that hinders its ventilation and heat dissipation, and ensure that there is enough space around the soft starter (greater than 150mm).

Regularly check whether the terminals of the power distribution line are loose, and whether the components in the cabinet are overheating, discoloring, scorching, and other abnormal phenomena.

Clean the dust regularly to avoid affecting the heat dissipation, to prevent the thyristor from being damaged due to excessive temperature rise, and to avoid leakage and short circuit caused by dust accumulation.

The dust can be cleaned with a dry brush, and can also be used for a tiger blower and a vacuum cleaner. For large dirt, it can be removed with an insulating rod. If necessary, it can be blown off with compressed air of about 0.6MPa.

Usually observe the operation of the fan, and if it is found that the speed of the fan is slow or abnormal, it should be repaired in time (such as removing grease, dust, oil, and replacing damaged or deteriorated capacitors). Replace damaged fans in a timely manner. If the soft starter is used without a fan, the thyristor will be damaged.

If the soft start use environment is humid or easy to dew, it should be dried with infrared light bulb or hair dryer frequently to drive off moisture to avoid leakage or short circuit. ^[3]