CN2135858Y - Ac motor phase-lose protector - Google Patents

Abstract

The utility model relates to an alternating-current motor phase-lose protector, which is mainly used for enabling the motor to automatically disengage from the electric network when the power supply of the motor has phase loss or phase lack. The utility model is characterized in that the protector regards three resistances as a sensor, and is installed into the full electronic formula by a diode, a rectifier, an electrolytic capacitance, a voltage stabilizing tube, a photocoupler, a transistor, a single-direction/bidirectional controlled silicon, an ac/dc converter, a plurality of resistances, etc. According to a certain circuit. Three input conducting lines are connected with the line connecting terminal of the motor; one zero line is connected with a power supply zero line, and two output conducting lines are connected with a controller. The utility model has the advantages of novel design, reasonable structure, small size, easy line connection, high sensitivity, high safety, sufficient protection of the motor, etc.

Description

Ac motor phase-lose protector

A kind of alternating current motor phase failure protector belongs to emergency protective circuit device technique field, is mainly used to when making when the three phase mains phase failure or phase shortage motor break away from electrical network automatically with protection motor and power circuit in the motor work.

Open phase protection roughly is divided into three kinds in prior art: first condenser type; it detects phase failure signal with three capacitors as detecting sensor; with mechanical relay as switch element; simple in structure; but capacitor must be high pressure resistant; thereby volume is big, heavy, and useful life is short.It two is induction types, and it is to do alternating magnetic field around the sensor alternating current motor power line with three air core coils, obtains phase failure signal.The subject matter that it exists is different confidential this class protectors of selecting different model for use of AC electrical, makes troubles to use.The third is exactly the full electronic protector, on three fuses that it has six roots of sensation detection line to be connected in parallel on respectively will to detect.The subject matter that its exists is: it only can detect the break-make situation of fuse in parallel, and can not detect non-full-phase state in the power supply grid, thereby motor can not get sufficient protection.Alternating current motor is the widely used a kind of power set of all trades and professions, and because of the operation of motor phase shortage causes the example of heavy economic losses of common occurrence, to study a kind of new more perfect open phase protection imperative for this reason.

The purpose of this utility model is to provide that a kind of structure is more perfect, defencive function is complete, safe and reliable, wiring is simple, easy to operate, volume is little, in light weight; under phase failure phase shortage situation, all can make alternating current motor break away from electrical network automatically, thus the new full electronic open phase protection that makes motor and circuit obtain adequately protecting.

Differ 120 ° basic principle according to three phase mains vector phase angle, at the subject matter that exists in the prior art, basic design of the present utility model is: make transducer with three resistance, three phase mains is checked, one end, three statures of these three resistance connect three phase mains, and three statures of the other end link together, and by rectifier ground connection, when three phase mains not during phase shortage, three phasor1s and be null value at this resistance common point place.Usually three-phase voltage may be slightly uneven, should go here and there diode with two reversal connections between ground and rectifier for this reason, with the counteracting unbalance voltage.Trigger photoelectrical coupler by the above-mentioned default phase signal that obtains, make it to be turned to output " 0 " and turn-off one-way SCR, cut off bidirectional triode thyristor then by output " 1 ".This bidirectional triode thyristor is connected in the interior control circuit loop of Motor Control case as the switch element with inductive load, when it is turned off under default phase signal triggers, also just the electricity went off for control circuit, thereby alternating current motor breaks away from electrical network, realizes purpose of design.

Of the present utility modelly be characterised in that described alternating current motor phase failure protector, the resistance-type power supply check sensing device of being made up of three resistance, two balances are regulated resistance, diode, photoelectrical coupler, four resistance, triode, one-way SCR, direct current--a-c transducer, bidirectional triode thyristor and three input lead A, B, C, a zero line and two output lead D with reversal connection diode, rectifier, electrochemical capacitor, voltage-stabiliser tube, saturation voltage drop ₁And D ₂Constitute; Each above-mentioned electronic devices and components are according to the circuit theory diagrams shown in the accompanying drawing 2; be installed on the single side printed wiring board; this wiring board by screw in the plastic casing of opposite opened; three above-mentioned input lead A, B, C receive on three terminals 2 of the alternating current motor that will protect; the zero line that zero line gets access to grid, output lead D ₁, D ₂Be connected in the control circuit.Circuit diagram shown in the above-mentioned accompanying drawing 2 comprises sensing, balance, rectification, photoelectricity coupling, direct current--exchange conversion and controlling output circuit six partly.Above-mentioned resistance-type power supply check sensing device, constitute with three all identical resistance of structure by resistance, three joints of these three resistance one ends meet above-mentioned three input lead A, B, C respectively, three joints of the other end are become a bit, and by above-mentioned rectifier and and two reversal connection diodes of the uneven usefulness of bucking voltage of this rectifier serial connection after ground connection.Above-mentioned photoelectrical coupler is made of input infraluminescence formula diode and output triode.

Outstanding advantage of the present utility model is: it is that transducer only connects motor with three leads that this protector adopts three resistance, and wiring is simple, full electronic; science rational in infrastructure; volume has only two matchboxes size like that, and wiring is installed and used all convenient, highly sensitive; perfect in shape and function is complete; no matter can not only check the phase failure in the fuse, and can also detect arbitrary phase shortage in the three phase network, be the phase failure or phase shortage; alternating current motor is broken away from from electrical network, thereby adequately protect motor.

Accompanying drawing 1 is one of the utility model most preferred embodiment assembling back overall structure schematic diagram, and Fig. 2 is its circuit theory and line map is installed that Fig. 3 is Motor Control and carries out loop diagram.1～3 three phase mains of forming transducer is checked resistance, 4～5 balanced voltages reversal connection diode, 6 rectifiers (4) among the figure, 7 electrochemical capacitors, 8 voltage-stabiliser tubes, 9 saturation voltage drops are regulated resistance, 10 diodes, 11 photoelectrical couplers, 12～14 and 18～19 are resistance, 15 triodes, 16 one-way SCRs, 17 direct currents--a-c transducer, 20 bidirectional triode thyristors, 21 A.C. contactors, 22 locking keys, 23 start buttons, 24 motor, 25～26 normally closed interlocks, 27 motor are carried out the fuse in loop, 28 single side printed wiring boards, 29 opposite opened plastic casings.

In this embodiment, resistance 1～3 all adopts the 39K.2W metalfilmresistor, diode 4～5 adopts the general diode of known technology, rectifier 6 adopts 1N4007.1A/1000V, electrochemical capacitor 7 is 2.2 μ F/16 volts, voltage-stabiliser tube 8 is 6V/ 1/2 W, resistance 9 is got 820 Ω, 1/4 W metalfilmresistor, diode 10 is the 1N4148 type, input diode in the photoelectrical coupler 11 is the infrared emission formula, output triode is the encapsulation of NPN type standard 6 pin biserials, resistance 12 is 240K 1/4 W metalfilmresistor, and resistance 13 is 390K 1/4 W metalfilmresistor, and resistance 14 is 10K 1/4 W metalfilmresistor, triode 15 is NPN type 9013.VCEO 〉=25 volts, one-way SCR 16 is 1A/800 volt MCR100-8, and direct current--a-c transducer 17 adopts known general standard component, and resistance 18 is got 150 Ω, 1/4 W metal film, resistance 19 is got 240 Ω, 1/2 W metal film, and bidirectional triode thyristor 20 is the 3A/600 volt.

As follows to alternating current motor phase failure protector operation principle described in the utility model and procedure declaration in conjunction with the accompanying drawings: A, B, the C three with this protector terminates on three binding posts of alternating current motor as shown in Figure 3, the zero line zero line that gets access to grid, D ₁, D ₂Be connected in the control circuit.When the every phase of three phase mains is all switched on, since resistance 1～3 common point that has two diodes 4 and 5 of reversal connection to offset to cause by each phase institute bringing onto load imbalance to zero vector and about 0.5 volt the error amount that may occur, at this moment the voltage in the output of rectifier 6 DC side is zero volt, infrarede emitting diode in the photoelectrical coupler is not luminous, its phototriode collector electrode is then exported " 1 ", the conducting that is triggered of the control utmost point of one-way SCR 16, the DC side of direct current--a-c transducer 17 is by short circuit, AC side and resistance 18,19, bidirectional triode thyristor 20 constitutes the loop, resistance 19 generation voltages are reduced to bidirectional triode thyristor 20 provides triggering signal, bidirectional triode thyristor 20 conductings.D ₁, D ₂Between 1.3 volts of tube voltage drops are arranged approximately.Press start button 23, A.C. contactor 21 energisings, normally closed interlock 25 and 26 closures, motor 24 normally moves.In carrying out the fuse 27 in loop, motor has one mutually on fusing or the power supply network during phase shortage, it is poor to produce a voltage vector between the common node of above-mentioned resistance 1～3 and the zero line, 2 volts of voltages of rectifier 6 output (its value depend on resistance 1～3 and 9 and the model of photoelectrical coupler 11), make the led lighting in the photoelectrical coupler 11, phototriode saturated (0.3 volt of saturation voltage drop is following), the one-way SCR 16 control utmost points are vised under trigger voltage, thereby are turned off; The DC side dead electricity of direct current---a-c transducer 17, normally closed interlock 25 and 26 disconnects, and motor 24 breaks away from electrical network, thereby is protected.

Change as present embodiment:

1, above-mentioned electrochemical capacitor 7, value is changeable, also can cancel, and decides on actual needs, if need from receiving phase failure signal a little longerly to the time that plays a protective role, then capacity can be more greatly, otherwise then littler, it is the shortest to have cancelled the time;

2, photoelectrical coupler 11 can replace with 4N28 or JIL117;

3, unidirectional any model little with 20 available volume with bidirectional triode thyristor 16, that parameter is identical with parameter that present embodiment is got all can replace.

Claims (4)

1; a kind of alternating current motor phase failure protector; by three electric capacity or air core coil; or some resistance; electric capacity; rectifier; diode; triode; controllable silicon and six roots of sensation detection line are formed, and of the present utility modelly are characterised in that described alternating current motor phase failure protector is by resistance-type power supply check sensing device 1～3; balance reversal connection diode 4～5; rectifier 6; electrochemical capacitor 7; voltage-stabiliser tube 8; saturation voltage drop is regulated resistance 9; diode 10; photoelectrical coupler 11; resistance 12～14 and 18～19; triode 15; one-way SCR 16; DC-AC converter 17; bidirectional triode thyristor 20 and three input lead A; B; C; a zero line and two output line D ₁, D ₂Constitute; Each above-mentioned electronic devices and components are installed on the single side printed wiring board 28 according to certain circuit; this wiring board 28 by screw in the plastic casing 29 of opposite opened; three above-mentioned input lead A, B, C connect three terminals of the alternating current motor 24 that will protect; the zero line that zero line gets access to grid, output lead D ₁D ₂Be connected in the control circuit.

2, alternating current motor phase failure protector according to claim 1 is characterized in that above-mentioned certain circuit is by sensing, balance, rectification, photoelectricity coupling, direct current---interchange conversion and controlling output circuit six are partly formed.

3, according to claim 1 and 2 described alternating current motor phase failure protectors; it is characterized in that above-mentioned resistance-type power supply check sensing device 1～3; constitute with 1,2,3 three all identical resistance of structure by resistance; three joints of these three resistance one ends meet above-mentioned three input lead A, B, C respectively; three joints of the other end are become a bit, and by above-mentioned rectifier 6 and and two reversal connection diodes 4 and 5 of the uneven usefulness of bucking voltage of this rectifier serial connection after ground connection.

4,, it is characterized in that above-mentioned photoelectrical coupler 11 is made of input infraluminescence formula diode and output triode according to claim 1 and 2 described alternating current motor phase failure protectors.

Images