CN2212856Y - Soft starting speed regulator for asynchronous motor - Google Patents

Abstract

The utility model relates to a soft-starting speed regulating device for an asynchronous motor, which comprises a main circuit, a controller which uses an 8098 single-chip machine as a core, and circuits, such as a trigger circuit, a synchronous pulse circuit, a regulating circuit for a starting current, etc., and is characterized in that the primary side of a synchronous transformer in the trigger circuit (2) is connected with the voltage of a power cord. The utility model has high cost performance, can automatically realize the process of the quasi optimum soft starting, and can realize smooth stepless speed regulation by a potentiometer, being applicable to the motors with various capacity.

Description

Soft starting speed regulator for asynchronous motor

The utility model relates to a kind of motor starting speed regulating device, belongs to electric and electronic technical field.

In recent years, domestic research to asynchronous motor starting, speed governing aspect has had remarkable progress, in order to overcome level is arranged, jumping and the shortcoming of over-current shock that electrical network and power consumption equipment are brought of starting process, people have added " translation circuit automatically " or system controlled by computer in product, reduced the loss of electric machine, play certain energy-conserving action, but they all are with starting of star angle or reduced voltage starting, cause above over-current shock inevitably twice; For this reason, the applicant has invented " the digital asynchronous machine soft start of the economical and energy saving type speed regulator " of Chinese patent " ZL93247188.9 ", suppresses circuit from seeking best Soft Start-up Process with starting current, but smooth starting and be set in maximum energy-saving point and go up and move.But it can not guarantee when lowest speed to be that broad pulse triggers, and it is unreliable to move on the motor of no center line, and antijamming capability is low.

The purpose of this invention is to provide a kind of former from seek best Soft Start-up Process and can be improved on the soft start speed regulating device basis of operation on the maximum energy-saving point, be fit to various capacity electrical machineries, asynchronous machine that antijamming capability is strong starts speed regulating device.

The utility model is realized its purpose as follows: it comprises the main circuit of being made up of thyristor or power model 1; With 8098 single-chip microcomputers is control core device 7; Be connected to the three-phase trigger circuit of controller 7 high-speed output ends, the output signal of controller 7 triggers little bidirectional thyristor behind photoelectricity coupling and pulse transforming, be connected to the gate pole of main bidirectional thyristor in the main circuit again through the secondary of synchrotrans; Be connected to the clock circuit 3 of controller 7 external interrupt application EXTINT end, synchrotrans TB _AThe voltage signal of secondary passes through transistor T every 180 ° after rectification, dividing potential drop ₁₁, photocoupler N ₁₁, transistor T ₁₂And T ₁₃To EXTINT end input pulse; Be connected to the starting current regulating circuit 4 of controller 7 high speed inputs, the current signal of current transformer secondary after rectification, computing are amplified by photocoupler and transistorized break-make to the NAND gate output signal, control controller 7 interrupt service routines is characterized in that: the synchrotrans TB in the A phase circuits for triggering _AFormer edge joint power line voltage U _AC, the synchrotrans TB in the B phase circuits for triggering _BFormer edge joint power line voltage U _BA, the synchrotrans TB in the C phase circuits for triggering _CFormer edge joint power line voltage U _CB(B phase, C phase circuits for triggering are with the A phase, so slightly in the accompanying drawing).

The utility model is simple and reasonable, ratio of performance to price height, and practicality and antijamming capability are strong, can not only make asynchronous motor under variable loads realize accurate best Soft Start-up Process, and can realize energy-saving run by the smooth adjustment rotating speed.

Embodiment further specifies the utility model below in conjunction with accompanying drawing.

Fig. 1 is the circuit theory diagrams of this starting speed regulating device.

Fig. 2 is the control procedure flow chart of this starting speed regulating device.

This starting arrangements for speed regulation mainly are made of seven parts: the main circuit that (1) is made up of IGCT or power model; (2) circuits for triggering; (3) clock circuit; (4) starting current regulating circuit; (5) rotation-speed setting circuit; (6) phase detector circuit; (7) controller take single-chip microcomputer 8098 chips as core. Each bidirectional thyristor gate pole all links to each other with circuits for triggering 2 in the main circuit 1, and clock circuit 3 is connected to the 8098 chip exterior interruption application EXTINT end of controller 7. Starting current regulating circuit 4 is connected to the high speed input of 8098 chips of controller 7. The open-phase protection of device adopts implicit mode, and phase discriminator 6 meets A, C and reaches mutually power supply center line N one, if wiring is errorless, A, C phase voltage are normal, then neon lamp flicker. And the voltage-stabilized power supply of the chips such as 8098 or 2764 is connected on AC power B and goes up mutually, if the B phase voltage is normal, then power supply indicator is bright, and device just can start to work, otherwise can not move.

In clock circuit 3, photocoupler N₁₁Diode on be parallel with a button K₂, when normally moving, voltage signal is through rectification, and dividing potential drop makes transistor T when high level₁₁Conducting, photocoupler N₁₁, transistor T₁₂、T ₁₃Also all conductings, thereby output pulse signal; When at the scene in service because various strong jammings when the SR of use 8098 can not be realized effectively stopping, are pressed K₂Can make photocoupler N₁₁The cut-off and stop paying out pulse, system is stopped immediately; When system resets, also must be earlier can start by 8098 SR, avoided " self-starting " phenomenon.

Because being in operation with the keyboard input speed can not be given and can only be given in static state, so the utility model is to add a two-way K switch in the conventional rotating speed given circuit₁One of the high input impedance mouth of circuit 5 access controllers 7, two-way switch K₁One be connected between two diodes, it is respectively D.C. regulated power supply U in two ends in addition₁The movable end b of end a and potentiometer is K switch₁When being allocated to a point, electric motor starting will be by full speed running after finishing; K₁When being allocated to the b point, namely use the given speed of service of the adjustable end of potentiometer, make system's variable speed energy saving operation. Can be at dymamic setting, working stability is reliable.

In each phase circuits for triggering, little bidirectional thyristor KS_A' or KS_B' or KS_C' gate pole and negative electrode between be parallel with capacitor C₁, can eliminate clutter interference pulse and burr, little bidirectional thyristor output waveform is improved greatly.

Pulse of the present utility model, triggering, seek optimum start and certainly, be prior art, so no longer repeat at this in processes and " the digital asynchronous machine soft start of economical and energy saving type speed regulator " basically identical that the aforementioned inventor invents such as the operations of energy-conservation point.

Embodiment: be used to implement the soft start and the variable speed energy saving operation of 7.5KW centrifugal water pump.The power conversion circuit of this device is made up of three bidirectional thyristors, circuits for triggering weekly the phase send the broad pulse at 180 ° at two intervals, clock circuit sends a lock-out pulse every 180 °.According to the loading condition of this water pump, the starting current times of adjusting is 4 times of rated current.Adopt DJ-III type economic run tester for electric motor and other supporting instrument to survey, situation is as follows:

The actual starting time is 15 seconds, and output voltage is reduced to 289.3V from 382.3V, COS

Be raised to 0.952 from 0.516, load factor then reduces to 0.405 by 0.54.

The full speed running rotating speed is 2930rpm

The full speed running load factor is B=0.54

Full speed running input active power P1=4.59KW

Full speed running input reactive power Q 1=7.6KVar

Full speed running active power of output P2=5.02KW

The energy-saving run rotating speed is 2410rpm

The energy-saving run load factor is B=0.405

Energy-saving run input active power P1=3.47KW

Energy-saving run input reactive power Q 1=1.11KVar

Energy-saving run active power of output P2=3.04KW

After this water pump adopted the utility model device, the economize on electricity situation was:

Meritorious fractional energy savings (4.59-3.47)/4.59=24.4%

Idle fractional energy savings (7.6-1.11)/7.6=85.4%

Test situation shows: adopt the utility model that tangible power savings is arranged.Because the water pump load factor is higher, function, energy-saving is arranged well below no function, energy-saving, power factor obviously rises, and is elevated to 0.952 from 0.516, and starting process is steady, and electrical network and motor are not had impact.In starting process, when electric current reached the setting current multiple, voltage topped out, and raise up to motor speed, and electric current drops to the hysteresis characteristic set point when following, just boosts again.If will shorten the starting time, starting current times can be strengthened.

Claims (5)

1, a kind of asynchronous motor soft start speed regulating device comprise: the main circuit of being made up of thyristor or power model (1); With 8098 single-chip microcomputers is control core device (7); Be connected to the three-phase trigger circuit of controller (7) high-speed output end, the output signal of controller (7) triggers little bidirectional thyristor behind photoelectricity coupling and pulse transforming, be connected to the gate pole of main bidirectional thyristor in the main circuit again through the secondary of synchrotrans; Be connected to the clock circuit (3) of controller (7) external interrupt application EXTINT end, synchrotrans TB _AThe voltage signal of secondary passes through transistor T every 180 ° after rectification, dividing potential drop ₁₁, photocoupler N ₁₁, transistor T ₁₂And T ₁₃To EXTINT end input pulse; Be connected to the starting current regulating circuit (4) of controller (7) high speed input, the current signal of current transformer secondary after rectification, computing are amplified by photocoupler and transistorized break-make to the NAND gate output signal, control controller (7) interrupt service routine is characterized in that: the synchrotrans TB in the A phase circuits for triggering _AFormer edge joint power line voltage U _AC, the synchrotrans TB in the B phase circuits for triggering _BFormer edge joint power line voltage U _BA, the synchrotrans TB in the C phase circuits for triggering _CFormer edge joint power line voltage U _CB

2, motor starting speed regulating device according to claim 1 is characterized in that: photocoupler N in the clock circuit (3) ₁₁Diode on be parallel with a button K ₂

3, motor starting speed regulating device according to claim 1 and 2 is characterized in that being connected to rotation-speed setting circuit (5) at the high input impedance mouth of controller (7), bidirectional switch K in the circuit ₁One be connected between two diodes, it is respectively D.C. regulated power supply U in two ends in addition ₁The movable end b of end a and potentiometer.

4, motor starting speed regulating device according to claim 1 and 2 is characterized in that being parallel with capacitor C between the gate pole of the little bidirectional thyristor in the circuits for triggering (2) and negative electrode ₁

5, motor starting speed regulating device according to claim 3 is characterized in that being parallel with capacitor C between the gate pole of the little bidirectional thyristor in the circuits for triggering (2) and negative electrode ₁

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