soft starter

soft starter Products Introduction VFS (Variable Frequency Starter) adopts the patented technology developed by RXPE independently to realize the function of discrete frequency conversion and stepless voltage regulation by controlling the thyristor. It can output 12.5 Hz, 25Hz and 50 Hz frequencies, and to realize a lower starting current with higher starting torque by controlling the voltage-frequency ratio of the motor. Also, a number of start and stop control methods can be realized, such as voltage inclination start, constant current start, soft stop, braking stop, and so on. At present, the product has passed the certification of German Classification Society, and are used in the 100,000 tons cargo ship in German. VFS-ApplicationVFS applies to drive soft start and soft stop of blowers, pumps and compressors, and other high-voltage three-phase AC induction motors or synchronous motors, and some occasions requiring fixed frequency conversion speed regulation. Energy saving is achieved. -- Pumps (such as water supply pump, sewage treatment pump, borehole pump, oil transport pump, etc.) -- Fans and blowers -- Extruders -- Centrifuges -- Mixers -- Compressors (such as spiral type, plunger-type, centrifugal type and turbine type) -- Refrigeration compressors -- HVAC systems -- Comminutors -- Conveyors -- Main power devices -- Propellers -- Anchor winches -- Bilge sewage pumpsVFS Working Principles Through the control of the thyristors firing angle to realize the output voltage and output frequency control, through the control, system generate 6 cyclic firing signal, Under certain frequency and by certain sequence to connect 5 group thyristors thus the output frequency could be 12.5Hz-25Hz-50Hz, At the same time, through the adjustment of the motor voltage/frequency ratio, to drive the motor start smoothly and accelerate, to rated speed to obtain the starting current and starting torque in a optimal to suit the transmission condition. Working Principles Besides, VFS could offer a soft stop function. It could simulate the motor stopping process, ensure the motor voltage reduce smoothly. In this way, it could avoid the driving stop suddenly, which will benefit the water pump driving (avoiding the water hammer effect) or the belt conveyer transmission. Also VFS offers step stop function, when stopping the frequency changer from 50Hz-25Hz-12.5Hz. The motor voltage accordingly reduced, and this play a brake action to realize immediate stop. VFS features--With lower starting current and higher starting torque through adopting the frequency conversion method, the starting current could be controlled 2 times the rated current minimum, the starting torque could reach 80-90% the rated torque.--A more flexible starting method we could select different starting combination according to the on-spot starting frequencies.--A more available motor starting control could realize starting both of forward and reverse directions, with free stop, soft stop and brake stop pf stop methods selection.--With adjustable starting time period and starting torque starting time and starting torque could be adjusted according to the on-spot requirement.--With full motor protection.--Adopting digital control method, with MODBUS, PROFIBUS and RS 485 etc. communication interface to suit the industrial applications.