CN2037888U - Phase-failure protector for triphase motor - Google Patents

Phase-failure protector for triphase motor Download PDF

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Publication number
CN2037888U
CN2037888U CN 88208942 CN88208942U CN2037888U CN 2037888 U CN2037888 U CN 2037888U CN 88208942 CN88208942 CN 88208942 CN 88208942 U CN88208942 U CN 88208942U CN 2037888 U CN2037888 U CN 2037888U
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CN
China
Prior art keywords
voltage
phase
capacitor
motor
circuit
Prior art date
Application number
CN 88208942
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Chinese (zh)
Inventor
梁有为
Original Assignee
梁有为
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
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Publication date
Application filed by 梁有为 filed Critical 梁有为
Priority to CN 88208942 priority Critical patent/CN2037888U/en
Publication of CN2037888U publication Critical patent/CN2037888U/en

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Abstract

Disclosed is a voltage detecting type phase-failure protector for a triphase motor, comprising an electrical source and signal testing circuit, a signal conversion circuit and a delaying output circuit. The utility model can realize the phase-failure protection of triphase motors of various models and specifications at a range of triphase line voltage line voltage unbalance <=13%. The three input terminals of the device are directly connected with the three connecting terminals of a motor, phase orders are random, and connections with a zero line or a neutral line are not required. The utility model has the advantages of convenient operation, low power consumption and strong anti-interference ability.

Description

The utility model relates to a kind of voltage detecting type threephase motor open phase protection.
In the various faults of motor, the open-phase running fault accounts for significant proportion.In order to prevent the phase failure, people have developed multiple open phase protection, are divided into voltage-type, current mode, phase type and temperature mode according to the phase failure signal difference that detects.And belong to the voltage-type open phase protection together zero-sequence voltage protection, negative sequence voltage protection and fracture of wire voltage protection are arranged, all there is certain problem separately in these several protective devices, zero-sequence voltage protection must be provided with artificial neutral point, the misoperation that produces in order to escape that residual voltage that voltage fluctuation and Voltage unbalance cause changes, therefore, cause the selection of zero phase-sequence relay action parameter relatively more difficult, cause its range of application to be restricted; The negative sequence voltage protector has overcome above-mentioned shortcoming, but sequence filter is too responsive to the imbalance of three-phase line voltage, and requires very harsh to the specifications parameter of Resistor-Capacitor Unit.In addition, also must follow the requirement of phase sequence during wiring; The protection range of fracture of wire voltage protector only is confined to the fuse part, and the number all too of its line is many, uses extremely inconvenient.
Problem in view of above-mentioned prior art existence; task of the present utility model is that a kind of universal performance of design is good; the branch of no phase sequence; protective feature is not influenced by voltage fluctuation and capacity motor, the accuracy of the imbalance of three-phase line voltage and component values is not had the voltage detecting type open phase protection of specific (special) requirements.
The utility model is made up of power supply and signal testing circuit, signal change-over circuit and time-delay output circuit.According to motor phase failure theory analysis as can be known, the voltage of motor changes during open-phase running, it is asymmetric that it is embodied in the terminal voltage of motor, asymmetric terminal voltage signal detects after utilizing power supply and signal testing circuit with the phase failure, this signal as the triggering signal of signal change-over circuit, make its conducting, and the signal of telecommunication become contact signal, thereby, force motor out of service by time-delay output circuit drive motors main circuit controller.
Below in conjunction with description of drawings structure of the present utility model and operation principle.
Fig. 1-be electrical schematic diagram of the present utility model
Fig. 2-be the utility model practice figure
As shown in Figure 1, the three-phase bridge full-wave rectifier, linear potentiometer R1, R2, diode D7, D8, capacitor C 1 and the voltage-stabiliser tube DW1 that are made of diode D1-D6 of power supply of the present utility model and signal testing circuit forms.The input of rectifier is connected with connecting terminal of motor after sealing in fuse RD1-RD3, voltage divider R1, R2 are connected between the both positive and negative polarity of rectifier output end, the negative pole of one termination rectifier output end of capacitor C 1, be connected between R1 and the R2 after the other end and the diode D7 differential concatenation, the anode of voltage-stabiliser tube DW1 connects the positive pole of rectifier output end, is connected on C1 and D7 connecting place after negative electrode and the diode D8 differential concatenation.
Before the motor phase failure, the voltage of binding post equates with service voltage, this moment, three line voltages were in a basic balance, three-phase voltage is after the rectification of three-phase bridge full-wave rectifier, the output peak value is Um, valley is the unidirectional pulsating dc voltage of 0.866Um, this voltage is through R1, the R2 dividing potential drop, the span R2/ of its voltage ratio (R1+R2)=0.7-0.85, the value of voltage ratio is 0.75 in this example, voltage after partial is crossed D7 fills UC1-R2/ (R1+R2) Um=0.75Um with to C1 voltage, no matter be at peak value or valley, the current potential that a is ordered occupy between Um 〉=Ua 〉=0.866Um, its height overall is in node b current potential (Ub=Uc1-0.75Um), and D8 ends, and C1 does not discharge, therefore voltage-stabiliser tube DW1 no current passes through, and power supply and signal testing circuit be output signal not.
When in three supply lines of motor arbitrary when disconnecting, its binding post Voltage unbalance of the motor of institute's on-load 〉=50% will surpass 15% (being confirmed by putting into practice).The peak value of the unidirectional pulsating voltage that obtain this moment is Um, but valley is less than 0.75Um, a point current potential is between Um 〉=Ua and Ua<0.75Um, when Ua<0.75Um, the current potential that a is ordered is lower than the current potential of node b, D8 forward conduction, C1 be through D8->DW1->R1->R2 discharge, and phase failure voltage signal is taken from formed discharge pressure drop on the positive best C1 of rectifier output end and the element between the D7 connecting place.
The signal change-over circuit is by field effect transistor BG, voltage-stabiliser tube DW2, diode D9-D12, capacitor C 2 and relay J 1 constitute, the grid of field effect transistor BG is connected on the D8 negative electrode, source electrode links to each other with the positive pole of rectifier output end, before the phase failure, and the no signal input, BG is in cut-off state, J1 discharges then only in the adhesive of the moment of C2 initial charge, and C2 fills the voltage of Uc2=Um with, during open-phase running, have only as Ua<0.75Um, power supply and signal testing circuit are input to detected phase failure signal among the field effect transistor BG, the BG conducting, and the voltage on the capacitor C 2 is higher than a point current potential, C2 is through D12->J1->D9->BG->R1->R2 discharge, and J1 gets electric adhesive, after BG changes over to and ends, pulsating direct current is crossed J1 to the C2 boost charge, repeat above-mentioned discharge process later on again,, and drive the double-throw contact action so J1 keeps adhesive.
The time-delay output circuit is by resistance R 3-R5; capacitor C 3-C4; trigger tube D13; controllable silicon CT and relay J 2 formed, and the effect of this circuit mainly is in order to prevent protective device in motor starting process and voltage fluctuation, and interference signal is invaded and the misoperation that produces; before the phase failure; J1 discharges, and J2 discharges, and normally-closed contact J2 is kept closed; behind the open-phase running; J1 adhesive, pulsating voltage are crossed R3 to C3 and C4 charging, after the several seconds kind; D13 punctures; the CT conducting, the J2 adhesive, normally-closed contact J2 disconnects.
The effect of R4 when C3 fills electric charge with because of interference, can be fallen tele-release by R4, to guarantee the precision of time-delay.
In this example, DW1, DW2 use as clipping element, also shouldn't, and field effect transistor BG can be substituted by other amplifier element.
This device compared with prior art has following characteristics:
1, easy to use. Three inputs of the present utility model can be connected to arbitrarily on three binding posts of motor, and no phase sequence requirement does not also have neutral point or zero line requirement, can put into operation after installing, and need not adjust and debug parameter.
2, three supply arbitrary disconnection in the electric lead, and the effect that its signal detects is fully identical.
3, be applicable to the threephase motor of protection all size model.
4, protective feature is not subjected to the influence of voltage fluctuation.
5, antijamming capability is stronger, and component parameter is not had specific (special) requirements, low in energy consumption (<4W), cost is low.
6, guarantee reliably working in the scope of on-Line Voltage imbalance≤13%.
The practical application of this device in the threephase motor control circuit as shown in Figure 2, the DB among the figure promptly is this device, and the normally-closed contact 4,5 of J2 in the time-delay output circuit of this device is serially connected in the loop of A.C. contactor.

Claims (5)

1; a kind of voltage detecting type threephase motor open phase protection; comprise power supply and signal testing circuit; signal change-over circuit and time-delay output circuit; it is characterized in that above-mentioned power supply and signal testing circuit are by three-phase bridge full-wave rectifier (D1-D6); linear potentiometer (R1-R2); diode (D7-D8); capacitor C 1 and voltage-stabiliser tube DW1 form; the input of rectifier seals in fuse (RD1-RD3) back and is connected with connecting terminal of motor; voltage divider (R1; R2) be connected between the both positive and negative polarity of rectifier output end; the termination negative pole of R2; the negative pole of one termination rectifier output end of capacitor C 1; be connected on R1 and R2 connecting place after the other end and the diode D7 differential concatenation; the anode of voltage-stabiliser tube DW1 connects the positive pole of rectifier output end; be connected on C1 and D7 connecting place after negative electrode and the diode D8 differential concatenation, phase failure signal take from the discharging current of capacitor C 1 or by this electric current at C1 and D7 connecting place formed voltage to the element between the rectifier output cathode.
2,, it is characterized in that the signal change-over circuit is made up of field effect transistor BG, diode D9-D12, voltage-stabiliser tube DW2, capacitor C 2 and relay J 1 by the described open phase protection of claim 1.
3, by the described open phase protection of claim 1, the output circuit that it is characterized in that delaying time is by resistance R 3-R5, and capacitor C 3-C4, trigger tube D13, controllable silicon CT and relay J 2 are formed.
4, by the described open phase protection of claim 1, it is characterized in that linear potentiometer voltage ratio R2/ (R1+R2)=0.7-0.85.
5,, it is characterized in that field effect transistor BG can substitute with other amplifier element by the described open phase protection of claim 2.
CN 88208942 1988-07-23 1988-07-23 Phase-failure protector for triphase motor CN2037888U (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN 88208942 CN2037888U (en) 1988-07-23 1988-07-23 Phase-failure protector for triphase motor

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN 88208942 CN2037888U (en) 1988-07-23 1988-07-23 Phase-failure protector for triphase motor

Publications (1)

Publication Number Publication Date
CN2037888U true CN2037888U (en) 1989-05-17

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Application Number Title Priority Date Filing Date
CN 88208942 CN2037888U (en) 1988-07-23 1988-07-23 Phase-failure protector for triphase motor

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CN (1) CN2037888U (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104022542A (en) * 2013-02-28 2014-09-03 三美电机株式会社 Charge/discharge control circuit and method for controlling charge/discharge

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104022542A (en) * 2013-02-28 2014-09-03 三美电机株式会社 Charge/discharge control circuit and method for controlling charge/discharge
CN104022542B (en) * 2013-02-28 2018-02-06 三美电机株式会社 Charge-discharge control circuit and charge/discharge control method

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