CN104917423A - Reduced-voltage starting control system - Google Patents

Abstract

The invention discloses a reduced-voltage starting control system. According to the invention, a circuit breaker QF, a contactor 1KM, a contactor 2KM, a contactor 3KM, an autotransformer QZB, a thermal relay FR and a motor form a starting main circuit. A time delay 2KT is arranged in the starting control circuit. After the full-voltage contactor 3KM starts to work, contacts of the time delay relay 2KT are disconnected in a time delay manner, so that a coil of the contactor 1KM on a power terminal of the autotransformer QZB loses power and the main contacts become off-contact and quits the starting process. The electric motor is totally detached from the autotransformer QZB and operates normally in full voltage. The reduced-voltage starting control system has characteristics of large starting stage quantity, small impact current and impact torque, good in smoothness and small in mechanical impact.

Description

A kind of reduced-voltage starting control system

Technical field

The invention belongs to electric motor starting control appliance technical field, especially relate to a kind of control system of motor auto-coupling voltage-reduction starting.

Background technology

Auto-coupling voltage-reduction starting utilizes autotransformer to reduce the starting resistor be added on motor stator winding, after motor start-up, then motor and autotransformer departed from, thus normally run under total head.Auto-coupling voltage-reduction starting is a kind of very ripe technology; because self coupling Starting mode is simple and direct, easy to maintenance; less demanding to operational environment; there is very strong practicality and cheap price advantage; be widely used; it can effectively reduce starting current, and protection motor, reduces the impact to electrical network.

It is few that existing auto-coupling voltage-reduction starting control system existence starts progression, and occur secondary pulse electric current and impact torque in starting process, flatness is bad, the problems such as mechanical shock is large, the lost of life.

Summary of the invention

The object of the invention is to improve the deficiency of existing control system so provide a kind of and start that progression is many, impulse current and impact torque is little, flatness is good, mechanical shock is little reduced-voltage starting control system.

The object of the present invention is achieved like this, a kind of reduced-voltage starting control system, be characterized in three-phase alternating current L11, L12, L13 connects the end of incoming cables of contactor 3KM main contacts respectively by circuit breaker Q F, the end of incoming cables of contactor 1KM main contacts, the leading-out terminal of contactor 3KM main contacts connects three centre taps of three phase electric machine M and autotransformer QZB by thermal relay FR, the power end of the outlet termination autotransformer QZB of contactor 1KM main contacts, make contactor 3KM, thermal relay FR and contactor 1KM, autotransformer QZB is and connects relation, the other end of autotransformer QZB connects the end of incoming cables of contactor 2KM main contacts respectively, the leading-out terminal of contactor 2KM main contacts is shorted together,

L11 in three-phase alternating current meets stop button TA after meeting fuse FU1, the parallel connected end of normally closed auxiliary contact 21 end of contactor 3KM, another termination start button QA of stop button TA, contactor 1KM often leaves auxiliary contact 23 end, on-delay closing contact 13 end of time relay 1KT, the parallel connected end often opening auxiliary contact 13 end of contactor 3KM, start button QA, on-delay break contact 11 end often opening the parallel end connection time relay 2KT of auxiliary contact 24 end of contactor 1KM, on-delay break contact 11 end of time relay 1KT and the parallel connected end of coil, the on-delay break contact 12 termination contactor 1KM of time relay 2KT often opens auxiliary contact 13 end, the parallel connected end often opening auxiliary contact 13 end of 2KM, contactor 1KM often leaves auxiliary contact 14 end, coil one end of often opening the parallel end connection contactor 1KM of auxiliary contact 14 end of 2KM, normally closed auxiliary contact 11 end of the on-delay break contact 12 termination contactor 3KM of time relay 1KT, coil one end of the normally closed auxiliary contact 12 termination contactor 2KM of contactor 3KM, on-delay closing contact 14 end of time relay 1KT, contactor 3KM often leaves normally closed auxiliary contact 11 end of the parallel end connection contactor 2KM of auxiliary contact 14 end, the parallel connected end often opening auxiliary contact 33 end of contactor 1KM, the coil of the normally closed auxiliary contact 12 termination contactor 3KM of contactor 2KM, the parallel connected end of run indicator HR, coil one end of often opening auxiliary contact 34 termination time relay 2KT of contactor 1KM, contactor 3KM normally closed auxiliary contact 23 termination contactor 2KM often leaves auxiliary contact 23 end, the parallel connected end of normally closed auxiliary contact 11 end of contactor 1KM, auxiliary contact 24 termination of often opening of contactor 2KM starts indicator light HY, and normally closed auxiliary contact 12 termination of contactor 1KM stops indicator light HG, the coil of contactor 1KM, the coil of 2KM, the coil of 3KM, the coil of time relay 1KT, the coil of 2KT, run indicator HR, start indicator light HY, stop the parallel connected end serial connection autotransformer QZB of indicator light HG, thermal relay FR, fuse FU2 meets the L13 in three-phase alternating current.

Compared with the prior art the present invention has following distinguishing feature and good effect: control system of the present invention is when the envelope star contactor 2KM main contact of autotransformer QZB disconnects, autotransformer QZB power end contactor 1KM main contact is due to time relay 1KT, the time delay disconnection effect of 2KT does not disconnect immediately, at this moment autotransformer QZB part winding is serially connected in electric motor starting loop as reactor, because the effect of reactor dividing potential drop makes motor start-up voltage be less than total head, but the voltage be greater than when self coupling starts, add startup progression, decrease the impact to electrical network, before total head contactor 3KM main contacts is not closed, contactor 1KM main contact disconnect after during this period of time in, there is not dead electricity inertia running status in motor, thus reduce secondary pulse electric current and impact torque, start-up course forwards total head running to and realizes seamless link, start flatness better, mechanical impact force reduces greatly.Setup times time-delay relay 2KT in startup control loop, after total head contactor 3KM drops into, the time delay of time-delay relay 2KT contact disconnects, make autotransformer QZB power end contactor 1KM coil losing electricity, main contacts disconnects and exits start-up course, motor and autotransformer QZB depart from completely, normally run under total head.Reduced-voltage starting control system after improving, practicality is stronger.

Accompanying drawing explanation

Below in conjunction with drawings and Examples, the present invention is described in further detail.

Fig. 1 is a kind of electronic circuit schematic diagram of the present invention.

Embodiment

A kind of reduced-voltage starting control system, with reference to Fig. 1, three-phase alternating current L11, L12, L13 connects the end of incoming cables of contactor 3KM main contacts respectively by circuit breaker Q F, the end of incoming cables of contactor 1KM main contacts, the leading-out terminal of contactor 3KM main contacts connects three centre taps of three phase electric machine M and autotransformer QZB by thermal relay FR, the power end of the outlet termination autotransformer QZB of contactor 1KM main contacts, make contactor 3KM, thermal relay FR and contactor 1KM, autotransformer QZB is and connects relation, the other end of autotransformer QZB connects the end of incoming cables of contactor 2KM main contacts respectively, the leading-out terminal of contactor 2KM main contacts is shorted together,

L11 in three-phase alternating current meets stop button TA after meeting fuse FU1, the parallel connected end of normally closed auxiliary contact 21 end of contactor 3KM, another termination start button QA of stop button TA, contactor 1KM often leaves auxiliary contact 23 end, on-delay closing contact 13 end of time relay 1KT, the parallel connected end often opening auxiliary contact 13 end of contactor 3KM, start button QA, on-delay break contact 11 end often opening the parallel end connection time relay 2KT of auxiliary contact 24 end of contactor 1KM, on-delay break contact 11 end of time relay 1KT and the parallel connected end of coil, the on-delay break contact 12 termination contactor 1KM of time relay 2KT often opens auxiliary contact 13 end, the parallel connected end often opening auxiliary contact 13 end of 2KM, contactor 1KM often leaves auxiliary contact 14 end, coil one end of often opening the parallel end connection contactor 1KM of auxiliary contact 14 end of 2KM, normally closed auxiliary contact 11 end of the on-delay break contact 12 termination contactor 3KM of time relay 1KT, coil one end of the normally closed auxiliary contact 12 termination contactor 2KM of contactor 3KM, on-delay closing contact 14 end of time relay 1KT, contactor 3KM often leaves normally closed auxiliary contact 11 end of the parallel end connection contactor 2KM of auxiliary contact 14 end, the parallel connected end often opening auxiliary contact 33 end of contactor 1KM, the coil of the normally closed auxiliary contact 12 termination contactor 3KM of contactor 2KM, the parallel connected end of run indicator HR, coil one end of often opening auxiliary contact 34 termination time relay 2KT of contactor 1KM, contactor 3KM normally closed auxiliary contact 23 termination contactor 2KM often leaves auxiliary contact 23 end, the parallel connected end of normally closed auxiliary contact 11 end of contactor 1KM, auxiliary contact 24 termination of often opening of contactor 2KM starts indicator light HY, and normally closed auxiliary contact 12 termination of contactor 1KM stops indicator light HG, the coil of contactor 1KM, the coil of 2KM, the coil of 3KM, the coil of time relay 1KT, the coil of 2KT, run indicator HR, start indicator light HY, stop the parallel connected end serial connection autotransformer QZB of indicator light HG, thermal relay FR, fuse FU2 meets the L13 in three-phase alternating current.

Operation principle of the present invention is as follows:

The breaker of plastic casing QF that closes connects three phase mains, by the adhesive of start button QA A.C. contactor 2KM coil electricity, its main contact closes, autotransformer QBZ coil is connected into star, meanwhile because contactor 2KM assists between normally opened contact 13 end, 14 ends closed, make contactor 1KM coil electricity adhesive and self-locking, the main contact of contactor 1KM closes by the voltage tap of autotransformer QBZ (such as 65%) by 65% of three-phase voltage access motor M, and motor M starts reduced-voltage starting, contactor 1KM assists normally opened contact 23 end, closed between 24 ends, make time relay 1KT coil electricity, and start timing by the time of having adjusted, after the time arrives, on-delay break contact 11 end of time relay 1KT, 12 ends are separated, contactor 2KM coil blackout, contactor 2KM normally opened contact all discharges, main contact disconnects, autotransformer QBZ coil Feng Xingduan is opened, now, because of time relay 2KT on-delay break contact 11 end, not yet disconnect between 12 ends, still there is voltage at contactor 1KM coil two ends, contactor 1KM continues closed, autotransformer QBZ part winding seals in starting-up later time as reactor, starting resistor continues to increase, motor M is steadily accelerated to start, between on-delay closing contact 13 end, 14 of time relay 1KT, end is closed, contactor 3KM coil is made to obtain electric adhesive and self-locking, contactor 3KM main contact connects motor M, contactor 3KM assists between normally opened contact 13 end, 14 ends closed, make time relay 2KT coil electricity, and start timing by the time of having adjusted, after the time arrives, on-delay break contact 11 end of time relay 2KT, 12 ends are separated, contactor 1KM coil decompression, its main contact disconnects, and cut off autotransformer QBZ power supply, motor M is run under total head, during for stopping, can press the stop button TA then whole power-off of control loop, motor M excises power supply and stall, the overload protection of motor M is completed by thermal relay FR.

Claims (1)

1. a reduced-voltage starting control system, it is characterized in that three-phase alternating current L11, L12, L13 connects the end of incoming cables of contactor 3KM main contacts respectively by circuit breaker Q F, the end of incoming cables of contactor 1KM main contacts, the leading-out terminal of contactor 3KM main contacts connects three centre taps of three phase electric machine M and autotransformer QZB by thermal relay FR, the power end of the outlet termination autotransformer QZB of contactor 1KM main contacts, make contactor 3KM, thermal relay FR and contactor 1KM, autotransformer QZB is and connects relation, the other end of autotransformer QZB connects the end of incoming cables of contactor 2KM main contacts respectively, the leading-out terminal of contactor 2KM main contacts is shorted together,

L11 in three-phase alternating current meets stop button TA after meeting fuse FU1, the parallel connected end of normally closed auxiliary contact 21 end of contactor 3KM, another termination start button QA of stop button TA, contactor 1KM often leaves auxiliary contact 23 end, on-delay closing contact 13 end of time relay 1KT, the parallel connected end often opening auxiliary contact 13 end of contactor 3KM, start button QA, on-delay break contact 11 end often opening the parallel end connection time relay 2KT of auxiliary contact 24 end of contactor 1KM, on-delay break contact 11 end of time relay 1KT and the parallel connected end of coil, the on-delay break contact 12 termination contactor 1KM of time relay 2KT often opens auxiliary contact 13 end, the parallel connected end often opening auxiliary contact 13 end of 2KM, contactor 1KM often leaves auxiliary contact 14 end, coil one end of often opening the parallel end connection contactor 1KM of auxiliary contact 14 end of 2KM, normally closed auxiliary contact 11 end of the on-delay break contact 12 termination contactor 3KM of time relay 1KT, coil one end of the normally closed auxiliary contact 12 termination contactor 2KM of contactor 3KM, on-delay closing contact 14 end of time relay 1KT, contactor 3KM often leaves normally closed auxiliary contact 11 end of the parallel end connection contactor 2KM of auxiliary contact 14 end, the parallel connected end often opening auxiliary contact 33 end of contactor 1KM, the coil of the normally closed auxiliary contact 12 termination contactor 3KM of contactor 2KM, the parallel connected end of run indicator HR, coil one end of often opening auxiliary contact 34 termination time relay 2KT of contactor 1KM, contactor 3KM normally closed auxiliary contact 23 termination contactor 2KM often leaves auxiliary contact 23 end, the parallel connected end of normally closed auxiliary contact 11 end of contactor 1KM, auxiliary contact 24 termination of often opening of contactor 2KM starts indicator light HY, and normally closed auxiliary contact 12 termination of contactor 1KM stops indicator light HG, the coil of contactor 1KM, the coil of 2KM, the coil of 3KM, the coil of time relay 1KT, the coil of 2KT, run indicator HR, start indicator light HY, stop the parallel connected end serial connection autotransformer QZB of indicator light HG, thermal relay FR, fuse FU2 meets the L13 in three-phase alternating current.