In the traditional drainage pump system, the Motor Used generally use Y / △ start, auto-step-down start and other start mode. These start-up methods exist a single control, not flexible, the impact of the system, easy to control components, maintenance workload and other shortcomings. Especially Y / △ start, start the current impact is relatively large, and with a secondary current shock, which may threaten the safety of the entire power supply system, and even worse, will cause a direct stop pump, causing the "water hammer" phenomenon, easy to give The entire drainage pump system creates an unpredictable loss. In recent years, with the maturity of computer technology, soft starters have been widely used in the field of drainage system. Soft starter is used to control the new Motor Used equipment, can achieve soft start, soft stop, low speed brake, light load energy and other protection. The soft starter has the advantages of small starting current, smooth starting speed, reliable starting performance and small impact on the power grid. The soft starter has improved its application in the control of the drainage pump. The existing soft start control system, using circuit breaker + soft start + bypass way to achieve. While the current Motor Used control, the vast majority have been used to control and protect the switchgear (CPS) as the main power distribution and protection of electrical components. In the existing Motor Used soft start control system, CPS, whether as a circuit breaker or bypass contactors are inappropriate, it can not play CPS small size, high breaking, full protection of the technical advantages. In order to solve this technical problem, the soft start control module is designed and developed, so that the soft start and soft stop function of the load can be realized by CPS + soft start control module. Compared with the traditional soft-start control system, not only reduces the required components, and makes CPS high breaking and protection functions can be fully developed.
1 CPS-based soft-start control system basic working principle CPS-based soft starter control system consists of a KB0 series CPS and KB0 supporting soft-start control module. The system is a Motor Used control system that integrates a variety of protection functions such as soft start, soft stop, overload, overcurrent, short circuit, block, block, overvoltage, undervoltage, undercurrent, phase loss, residual current and so on. The system also has a communication function, the Motor Used can start, stop and run the process of a variety of current, voltage data and fault sent to the host computer for alarm or protection. Before introducing the basic working principle of the system, the working principle of the soft start control module is introduced first. Compared with the traditional Y / △ starter, auto-step-down starter, etc., the initial torque of the soft starter system based on CPS can be adjusted according to the load, the adaptability of the load is strong, and the built-in bypass contactor is soft Start after the completion of timely conduction, so that the SCR only work in the Motor Used start and stop phase, greatly extending the life of the entire system.
2 system start and stop mode system consists of KB0 and soft start module, KB0 is responsible for the completion of the main circuit of the various protection and the host computer data communication, soft start control module is responsible for the completion of the Motor Used soft start, bypass, soft stop The KB0 main circuit connected, press the start button, soft start control module will be based on the man-machine interface on the initial voltage potentiometer set thyristor conduction angle, resulting in an initial voltage to overcome the Motor Used static friction torque, Reduce the current start of the Motor Used generated by the impact of the current, the initial voltage can be set. Then, according to the man-machine interface on the start time potentiometer set value to continuously adjust the thyristor conduction angle, the Motor Used start voltage control, to achieve the Motor Used soft start. After the soft-start process is completed, the soft-start control module internal bypass contactor bypass the main circuit to reduce the working time of the thyristor. When the stop button is pressed, the soft start control module switches the main return bypass contactor back to the thyristor control circuit, and then adjusts the thyristor angle according to the stop time setting value of the display unit To reduce the thyristor output voltage, to achieve a smooth soft stop. No matter what the soft starter in the working state, once the soft starter control module detects the Motor Used failure, KB0 will be the first time to cut off the main circuit to achieve the protection of the Motor Used, while the soft-start control module reset, wait The next start signal is issued.