CN201181840Y - Phase-loss protector for three-phase electrical motor - Google Patents
Phase-loss protector for three-phase electrical motor Download PDFInfo
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- CN201181840Y CN201181840Y CNU2008200768228U CN200820076822U CN201181840Y CN 201181840 Y CN201181840 Y CN 201181840Y CN U2008200768228 U CNU2008200768228 U CN U2008200768228U CN 200820076822 U CN200820076822 U CN 200820076822U CN 201181840 Y CN201181840 Y CN 201181840Y
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- motor
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Abstract
The utility model relates to a phase-lacking protector of a three-phase motor, in particular relates to a motor safety protection device, which comprises a transformer (B), a plurality of rectifying filtering circuits (D10, D11, D12, D13, D14), and a relay (J), wherein, the input end of the transformer (B) is respectively connected with any two phases of a three-phase power source, and the output end is connected with the rectifying filtering circuits (D10, D11, D12, D13, D14). The relay (J) is connected with the rectifying filtering circuits (D10, D11, D12, D13, D14) through a control circuit; the input end of the three-phase power source is provided with a star balancing symmetrical circuit, a rectifying filtering circuit and a voltage comparison circuit; the star balancing symmetrical circuit is connected with the three-phase power source; the neutral point of the three-phase alternative-voltage is taken out through the star balancing symmetrical circuit; after being connected with the rectifying filtering circuit, the relay is connected with the control circuit through the voltage comparison circuit. The relay only has one mechanical contact, thereby overcoming the weakness of the malfunction of the protection system caused by the poor contact of the mechanical contact, so that the protector is safer and more reliable to run. In addition, the protection action time of the device is rapid, and is 0.5 second; moreover, the structure is simple, the cost is low, and the installation is convenient for no zero line is required.
Description
Technical field
The utility model relates to a kind of motor safety protective device, is specially a kind of open-phase protector for three-phase motor.
Background technology
Three phase electric machine is when normal operation, and when phase shortage occurring owing to some well-known reason power supply, current of electric increases, and exceeds rated current, makes motor coil overheated, thereby burns motor.Be damaged for fear of motor when the power supply generation open-phase fault, several alternative open-phase protector for three-phase motor are provided in the prior art.02277176.X disclosed open-phase protector for three-phase motor is a normal open switch characteristic of utilizing relay, realizes the open-phase protection of motor.But because the contact of relay is a mechanical contact; the problem of the poor contact of contacts that causes because the contact is too much can cause protector system down; the operate time of influence or prolongation system; motor also can cause its decreasing insulating because of coil is overheated, reduces the useful life of motor or burns motor.200620051072.X disclosed open-phase protector for three-phase motor; transformer, current rectifying and wave filtering circuit and relay have been adopted; this protector is when phase shortage appears in power supply in motor operation course; because transformer still has the power supply input; protective circuit can because of charged move malfunctioning, do not reach the protection motor purpose.
Summary of the invention
The purpose of this utility model provides a kind of compared with prior art when the power supply open-phase fault takes place, open-phase protection fast, safety, reliable operate time, and open-phase protector for three-phase motor simple in structure, that cost is low, easy for installation.
For realizing described purpose; open-phase protector for three-phase motor of the present utility model comprises transformer, current rectifying and wave filtering circuit and relay; the input of its transformer is connected with any two of three phase mains respectively; output is connected with current rectifying and wave filtering circuit; be connected by control circuit between described relay and the current rectifying and wave filtering circuit, this control circuit is formed by connecting by the base stage supplying resistance of control triode, damper diode and control triode.Input design at three phase mains has star-like balanced, symmetrical circuit, rectification, filter circuit and voltage comparator circuit.Described star-like balanced, symmetrical circuit is connected with three phase mains, and the neutral point through star-like balanced, symmetrical circuit taking-up three-phase alternating voltage is connected to form and corresponding three direct voltages of three-phase alternating current line voltage with rectification, filter circuit; Rectification, filter circuit are connected with control circuit by voltage comparator circuit.
Described star-like balanced, symmetrical circuit is to be made of the resistance parallel connection;
Described rectification, filter circuit are to be made of diode, resistance, electric capacity connection in series-parallel;
Described voltage comparator circuit is to be made of diode, resistance, electric capacity, voltage-stabiliser tube and controllable silicon connection in series-parallel.
The used relay of open-phase protector for three-phase motor described in the utility model has only a mechanical contact, has overcome because of the mechanical contact loose contact causes the malfunctioning defective of protection system, makes that the protector operation is safer, reliable.In addition, the utility model operate time of protection is fast, only is 0.5 second, and simple in structure, and cost is low, owing to do not need the connecting to neutral line, it is very convenient to install.
Description of drawings
Fig. 1 is a circuit structure diagram of the present utility model.
Fig. 2 is the connection diagram of the utility model and power supply and motor.
Fig. 3 is the connection diagram of the utility model and power supply and motor.
Embodiment
With reference to accompanying drawing, will describe specific embodiments of the present utility model in detail.
Fig. 1 has provided the circuit structure of open-phase protector for three-phase motor described in the utility model.As shown in Figure 1, this open-phase protector for three-phase motor has five terminals, and A, B, C are the three-phase alternating-current supply input, and K1, K2 are the switching value control output end, and K1, K2 are normally open, is serially connected with in the alternating current machine secondary starting and stopping control loop.
The input of transformer B is connected with A, the B of three phase mains respectively, and output is connected with current rectifying and wave filtering circuit D10, D11, D12, D13, C4.Be connected by control circuit between relay J and the current rectifying and wave filtering circuit.This control circuit is made of base stage supplying resistance R10, the R11 of control triode Q1, damper diode D14 and control triode Q1.The collector electrode of control triode Q1 is connected with relay J, and emitter is connected with current rectifying and wave filtering circuit, and base stage then is connected with controllable silicon Q2 in the control circuit.Normally opened contact connection of relay J and K1, K2 switching value control output end.
Input design at three phase mains A, B, C has star-like balanced, symmetrical circuit and connected rectification, filter circuit and voltage comparator circuit.Star-like balanced, symmetrical circuit is made of R1, R2, R3 parallel connection; Rectification, filter circuit by diode D1, D2, D3,, resistance R 4, R5, R6,, capacitor C 1, C2, C3, resistance R 7, R8, R9 connection in series-parallel constitute, resistance R 7, R8, R9 are the discharge resistances of capacitor C 1, C2, C3; Voltage comparator circuit is by six diode D4, D5, D6, D7, D8, D9, resistance R 13,, capacitor C 5 and voltage-stabiliser tube D15, controllable silicon Q2 connection in series-parallel constitute.
A, B, C three-phase alternating voltage are via star-like balanced, symmetrical circuit R1, R2, R3, take out the neutral point of three-phase alternating voltage, simultaneously again through rectification, filter circuit diode D1, D2, D3,, resistance R 4, R5, R6,, capacitor C 1, C2, C3, resistance R 7, R8, R9, on capacitor C 1, C2, C3, form and corresponding three direct voltages of three-phase alternating current line voltage, this direct voltage is through diode D4, D5, D6, D7, D8, D9 in the voltage comparator circuit, and resistance R 13 backs form a comparative voltage on capacitor C 5.Resistance R 12 is the discharge resistance of capacitor C 5.Voltage-stabiliser tube D15 is 20 volts of voltage-stabiliser tubes.
When three phase mains normally moved, the phase voltage between A, B was powered to relay J and control circuit behind D10, D11, D12, D13, C4 rectifying and wave-filtering through 12 volts of alternating voltages of transformer B output.Control triode Q1 keeps the saturation conduction state, and relay J obtains the operating voltage adhesive, K1, K2 closure, motor operate as normal.This moment the three-phase alternating voltage symmetrical balance, three direct voltages behind rectifying and wave-filtering equate that the voltage that forms on the capacitor C 5 in the voltage comparator circuit is 0 volt.Perhaps when the unbalance voltage of three-phase alternating voltage is very little, the voltage that forms on capacitor C 5 after relatively through rectifying and wave-filtering is also very little, deficiency is so that voltage-stabiliser tube D15 conducting, also can not trigger controllable silicon Q2 conducting, controllable silicon Q2 is in cut-off state, to not influence of control triode Q1, relay J conducting, K1, K2 closure, the motor operate as normal.
When three phase mains in that motor is in service when phase shortage occurring suddenly, three-phase alternating current phase voltage disequilibrium, unbalanced three-phase alternating current phase voltage forms a higher comparative voltage through rectification, filtering, after relatively, with voltage-stabiliser tube D15 conducting, thereby trigger controllable silicon Q2 conducting, the base voltage of control triode Q1 is by short circuit, and control triode Q1 ends, and the relay J voltage contact of losing the job disconnects.Because K1, K2 be serially connected with in the motor starting and stopping control circuit, the power supply of control circuit is cut off, and the contactor main contacts in time disconnects, and cuts off motor power, makes motor protected, and has avoided three characteristics of the middle term AC power phase shortage and causes motor to be damaged.
Fig. 2, Fig. 3 have provided the connected mode of the utility model and power supply and motor.DK is a master switch among the figure, and RD1 is total insurance, and RD2 is the secondary insurance, and ZC is a main contactor, and RJ is a thermal protector, and M is a three phase electric machine, and TA is a stop button, and QA is a start button, and BHQ is this open-phase protector for three-phase motor.
Shown in Figure 2, this open-phase protector for three-phase motor is connected to the upper end of main contactor ZC, when open-phase fault appears in three phase mains, open-phase protector for three-phase motor BHQ action, motor M is out of service.But this moment, open-phase protector for three-phase motor BHQ was still charged.If when motor M phase shortage occurs before not starting, open-phase protector for three-phase motor BHQ will work in guard mode, secondary control circuit power supply is cut off, and motor M can not start.
Shown in Figure 3, this open-phase protector for three-phase motor is directly in parallel with motor M, when open-phase fault occurring, cuts off the electricity supply the protection motor M.This moment, motor M and open-phase protector for three-phase motor BHQ all cut off the power supply, and be out of service.If motor M when A phase shortage occurs mutually before not starting, is pressed start button QA, motor will obtain a three phase mains of phase shortage; moment works in abnormality, and behind the start button QA to be released, open-phase protector for three-phase motor BHQ moves at once; cut off the electricity supply the protection motor.
Claims (5)
1; a kind of open-phase protector for three-phase motor; comprise transformer (B); current rectifying and wave filtering circuit (D10; D11; D12; D13; C4) and relay (J); the input of its transformer (B) is connected with any two of three phase mains respectively; output and current rectifying and wave filtering circuit (D10; D11; D12; D13; C4) connect; it is characterized in that: described relay (J) and current rectifying and wave filtering circuit (D10; D11; D12; D13; C4) connect by control circuit between; input design at three phase mains has star-like balanced, symmetrical circuit; rectification; filter circuit and voltage comparator circuit; described star-like balanced, symmetrical circuit is connected with three phase mains; through the neutral point of star-like balanced, symmetrical circuit taking-up three-phase alternating voltage, with rectification; filter circuit connects the back and is connected with control circuit by voltage comparator circuit.
2, open-phase protector for three-phase motor according to claim 1 is characterized in that: described control circuit is to be formed by connecting by the base stage supplying resistance (R10, R11) of controlling triode (Q1), damper diode (D14) and control triode.
3, open-phase protector for three-phase motor according to claim 1 is characterized in that: described star-like balanced, symmetrical circuit is to constitute by resistance (R1, R2, R3) is in parallel.
4, open-phase protector for three-phase motor according to claim 1; it is characterized in that: described rectification, filter circuit are by diode (D1, D2, D3); resistance (R4, R5, R6), electric capacity (C1, C2, C3), resistance (R7, R8, R9) connection in series-parallel constitutes.
5, open-phase protector for three-phase motor according to claim 1; it is characterized in that: described voltage comparator circuit is by diode (D4, D5, D6, D7, D8, D9); resistance (R13, R12), electric capacity (C5), voltage-stabiliser tube (D15) and controllable silicon (Q2) connection in series-parallel constitute.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
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CNU2008200768228U CN201181840Y (en) | 2008-04-11 | 2008-04-11 | Phase-loss protector for three-phase electrical motor |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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CNU2008200768228U CN201181840Y (en) | 2008-04-11 | 2008-04-11 | Phase-loss protector for three-phase electrical motor |
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CN201181840Y true CN201181840Y (en) | 2009-01-14 |
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CNU2008200768228U Expired - Fee Related CN201181840Y (en) | 2008-04-11 | 2008-04-11 | Phase-loss protector for three-phase electrical motor |
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101593966B (en) * | 2009-04-01 | 2011-04-20 | 卫斌鹏 | Open-phase protector for three-phase motor |
CN101539783B (en) * | 2009-04-29 | 2011-07-20 | 卫斌鹏 | Automatic pumping controller |
-
2008
- 2008-04-11 CN CNU2008200768228U patent/CN201181840Y/en not_active Expired - Fee Related
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN101593966B (en) * | 2009-04-01 | 2011-04-20 | 卫斌鹏 | Open-phase protector for three-phase motor |
CN101539783B (en) * | 2009-04-29 | 2011-07-20 | 卫斌鹏 | Automatic pumping controller |
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Legal Events
Date | Code | Title | Description |
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C14 | Grant of patent or utility model | ||
GR01 | Patent grant | ||
C17 | Cessation of patent right | ||
CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20090114 Termination date: 20110411 |