CN2043798U - Electronized multifunctional protector for three phase motor - Google Patents
Electronized multifunctional protector for three phase motor Download PDFInfo
- Publication number
- CN2043798U CN2043798U CN 89200446 CN89200446U CN2043798U CN 2043798 U CN2043798 U CN 2043798U CN 89200446 CN89200446 CN 89200446 CN 89200446 U CN89200446 U CN 89200446U CN 2043798 U CN2043798 U CN 2043798U
- Authority
- CN
- China
- Prior art keywords
- phase
- current
- voltage
- motor
- unit
- Prior art date
- Legal status (The legal status 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 status listed.)
- Expired - Lifetime
Links
Images
Landscapes
- Protection Of Generators And Motors (AREA)
Abstract
The utility model discloses an electronic multifunctional protector for a three phase motor. The utility model is characterized in that three phase current can be sampled; the wide inverse time-lag of over-current protection ranges from 9 seconds to 20 minutes; three phase unbalance and open-phase protection have movable delaying; the protector can protect a motor from the unbalance of three phase current, phase lack, locked rotations, overcurrent, short circuit, overvoltage, undervoltage and creepage.
Description
The utility model relates to electric motor protective device, is specifically related to a kind of electronic type three phase electric machine comprehensive protection device.
Motor protecter is a kind of electric motor protective device commonly used at present.But disclosed protector in the prior art (as CN87216391 and 87204387) lacks the unbalance protection of three-phase current function, and its open-phase protection time-delay is changeless; The inverse time lag scope of overcurrent protection is narrower, causes the heat accumulation of motor not protect to interrupted overload.
The electronic type three phase electric machine comprehensive protection device that the purpose of this utility model is a kind of inverse time lag wide ranges that can protect, have activity time-delay, overcurrent protection to three-phase current unbalance of design, can protect the heat accumulation that interrupted overload causes.
The design that the utility model provides comprises sampling unit, residual current protective unit, and three-phase imbalance, phase-lacking protective unit, over-current protecting unit, overvoltage, under-voltage protection unit and performance element is characterized in that:
1) sampling unit includes three current transformers, can detect respectively three-phase current like this.
2) three-phase imbalance, phase-lacking protective unit comprise activity delay unit and the isolated amplifier that is inversely proportional to the degree of detecting unit, time-delay length and three-phase current unbalance the while also is inversely proportional to the size of current of motor.Like this, for the three-phase current unbalance degree big or when starting the delay time of phase shortage just very short, with the protection motor of in time cutting off the electricity supply; And the time-delay of or in service phase shortage little to the current imbalance degree is just long, to avoid the unnecessary protection action.
3) over-current protecting unit comprises two voltage comparators that reference voltage is different, reference voltage divider resistance R
17, R
16, R
7, R
8, sampled signal divider resistance R
23, R
24, charging capacitor Ct, two charging resistor Rt1, Rt2 that resistance is different, isolated amplifier M
5With discharger R
11, D
12, M
1During light the overload, first voltage comparator conducting, to charging capacitor Ct charging, charging resistor is bigger because signal voltage is less through bigger charging resistor Rt for sampled signal voltage, so can obtain long time-delay.When heavily transshipping, second also conducting of voltage comparator, simultaneously to the charging capacitor charging, because signal voltage is bigger, charging resistor Rt2 is less through two charging resistors for signal voltage, so time-delay can be very short.So just can obtain very wide reference time delay.During overcurrent, charging capacitor is not by discharger R
11, D
12, M
1Discharge, operating current is little, and discharge is just fast, and the big discharge of operating current is just slow, therefore can reflect the heat accumulation situation of the interrupted overload of motor, when heat accumulation surpasses design load, the protector action.
The utility model has following accompanying drawing:
Fig. 1 protector functional-block diagram
Fig. 2 protector electrical schematic diagram
Fig. 3 three-phase imbalance, phase-lacking protective unit block diagram
V during Fig. 4 three-phase balance
10, V
11Oscillogram
A V when phase current is big in Fig. 5 three-phase current
10, V
11, V
13Oscillogram
V when two-phase current is big in Fig. 6 three-phase current
10, V
11, V
13Oscillogram
Fig. 7 protector components and parts relative position schematic diagram
Below in conjunction with accompanying drawing the utility model is described in detail.
Fig. 1 is the utility model functional-block diagram, comprises sampling unit 1, residual current protective unit 2, over-current protecting unit 3, three-phase imbalance, phase-lacking protective unit 4, overvoltage, under-voltage protection unit 5, performance element 6 and power supply 7.
Fig. 2 is the utility model electricity principle schematic.The same with prior art, sampling unit 1 is selected current transformer for use, it is characterized in that selecting for use three current transformers respectively three-phase current to be sampled, and all can protect to guarantee arbitrary breaking down mutually, and functional reliability is higher.Sampling unit 1 is by mutual inductor A, B, C, diode D
1, D
2, D
3, D
4, resistance R
0, R
1, potentiometer W and capacitor C
1Form.
Three-phase imbalance, phase-lacking protective unit comprise that detector 8, delayer 9 and isolated amplifier 10(are referring to Fig. 3).The time-delay length of delayer 9 and the degree of three-phase current unbalance are inversely proportional to, and the size of while and motor working current also is inversely proportional to.Detector 8 is by voltage comparator M
3, resistance R
4, R
5, R
6With diode DW
1Form; Activity delayer 9 is by resistance R
12, R
21, R
14, diode D
9, D
15And capacitor C
3Form; Isolated amplifier 10 is by diode D
7With voltage comparator M
4Form.
When undesired or motor coil has partial short-circuit when line voltage, because serious over-current phenomenon avoidance might not take place each phase current, so only can not find this class fault by over-current protecting unit.The utility model has been selected three current transformers for use, and the three-phase current to motor carries out signal sampling respectively, takes out one of amplitude maximum in the motor three-phase current and all the other phase current magnitude and compares.Sampled signal is through D
1, D
2, D
3Behind the three phase half wave rectification, regulated by potentiometer W, make sampled signal output valve Vj greater than certain value (for example 6V), sampled signal one tunnel is through D
4Isolation, C
1Filtering becomes direct current signal Vj, then through R
5, R
6Divide and be sent to voltage comparator M
311 ends, as M
3Reference voltage V
11Another road of sampled signal is through R
4Deliver to M
310 ends, this signal is pulsating direct current signal V
10V
10, V
11Waveform when three-phase balance is referring to Fig. 4, at this moment, and M
3Reference voltage V
11Be designed to be lower than slightly M
3The pulsating direct current signal V of 10 ends
10Potential minimum, i.e. V
11Always less than V
10, M
313 ends be electronegative potential, capacitor C
3Last no-voltage, performance element is failure to actuate.
During the motor three-phase current unbalance, M
3The reference voltage V of 11 ends
11In three variations of half cycle in the time very little (referring to Fig. 5, Fig. 6), but M
3The pulsating direct current signal V of 10 ends
10Variation but big (referring to Fig. 5, Fig. 6).As t at a time
1Beginning V
10＜V
11, to t
2Constantly recover V again
10＞V
11, so at t
1～t
2Time in M
313 ends all export high potential, through D
9To C
3Charging.At t
2V constantly
10＞V
11, C
3Through R
14Discharge.Along with the increase of uneven degree, t
1～t
2Time also increase, charging interval lengthening, shorten discharge time relatively, C
3Power on and press the increase of increasing degree degree.Work as C
3On voltage when being increased to design load (for example 5V), promote performance elements 6 through isolated amplifier 10, make the protector execute protection.
Charging capacitor C
3The high speed of the voltage rise that powers on is also relevant with the size of sampled voltage Vj.When the motor vacant phase starting, current of electric is very big, and at this moment sampled voltage V is very high, and this voltage is to delay capacitor C
3Charging, C
3On voltage reach design load soon, for example can cut off motor power less than 0.1 second time chien shih protector action.When motor is in operation phase shortage, current of electric when not very big again, sampled voltage Vj is just smaller, delay capacitor C
3On voltage to rise to time of design load just longer, can obtain the time-delay of longer (for example 1～2 second), to adapt to the different phase shortage situation of motor, the unnecessary protection action of having avoided constant time lag to cause.
Over-current protecting unit 3 comprises two voltage comparator M
1, M
2, reference voltage divider resistance R
17, R
16, R
7, R
8, signal voltage divider resistance R
23, R
24, charging capacitor Ct, two charging resistor Rt1, Rt2 that resistance is different, isolated amplifier M
5With the discharger R of discharge resistance with the motor working current variation
11, D
12, M
1
When motor working current does not have overrate, sampled signal voltage V
jLower, through resistance R
23, R
24Deliver to voltage comparator M after the dividing potential drop
19 ends and voltage comparator M
27 ends, suitably select divider resistance R
7, R
8, R
17, R
16, make M
1The voltage V of 9 ends
9Be lower than M
1The voltage V of 8 ends
8, make M
2The voltage V of 7 ends
7Be lower than M
2The voltage V of 6 ends
6, i.e. V
9＜V
8, V
7＜V
6, this moment M
114 ends and M
21 end be zero potential.Therefore, when the motor nonoverload, there is not voltage on the charging capacitor Ct, isolated amplifier M
5The voltage V of 4 ends
4Be lower than the voltage V of 5 ends
5, i.e. V
4＜V
5So, M
5The voltage V of 2 ends
2Be high potential, performance element 6 is failure to actuate.
When motor gently transshipped, signal voltage Vj rose, through R
23, R
24Deliver to M after the dividing potential drop
19 ends, make V
9＞V
8, M at this moment
1Conducting, M
114 terminal potentials rise V
14Set point be greater than M
5V
5Owing to be light overload, the Vj value is not very big, by design M of the present utility model
2V
7Still less than V
6, M
21 end still be zero potential.Therefore, Vj only charges to Ct by charging resistor Rt1, because the Vj value is not very big, and the resistance of Rt1 is very big again, so the rising of the voltage Vc on the Ct is very slow, make Vc greater than V again
5Need the long time, for example can accomplish 20 minutes～1 hour, so just realized the long time limit delay function of light overload.
Along with the rising of current of electric, Vj rises to very high value, M gradually
1V
9And M
2V
7Also raise, make V
9＞V
8, V
7＞V
6, M
114 ends, M
21 end all become high potential.Vj charges through Rt1, Rt2 two road direction Ct.Because Vj is very high, Rt2 is little a lot of than Rt1 again, accelerates so Ct goes up the voltage Vc rate of climb, and the time that is charged to design load shortens.For example, when load-rate of motor was 700%, this time can foreshorten to 9 seconds.As Vc＞V
5The time, protector execute protection function is cut off motor power.So just realized the short duration defencive function when motor heavily transships.
In the real work (as electric saw, electric planer), motor normally is operated in the variability load condition, and interrupted overload phenomenon is arranged during motor, and promptly the break-make ratio of motor overload changes
Break-make ratio=(nonoverload time * rated current * rated current)/(overload time * operating current * overload current.)
The motor overload electric current is big more, overload time is long more, and break-make ratio is more little.Along with reducing of break-make ratio, motor will produce heat accumulation, surpasses certain hour, and the life-span of motor will be affected; Break-make ratio is during greater than certain value, and motor can operate as normal, so will distinguish this two kinds of different situations.And all there is not this function in the prior art.
By design of the present utility model, during motor overload, the current potential Vc on the Ct raises gradually, and how many interior at one time Vc rises by the current of electric decision, is directly proportional with current value.During the motor nonoverload,,, have only Ct to pass through discharge paths R so V can not charge to Ct owing to 14 ends of M, 1 end of M all are electronegative potential
11, D
12To M
1The discharge of 14 ends.How much what Vc reduced is determined by the length of motor nonoverload time and the size of operating current.
When break-make ratio during less than certain value Ct institute charge volume more than the electric weight that bleeds off, Vc will intermittently rise like this, when Vc rose to design load, protector was an execute protection, prevented that the heat accumulation of interrupted overload from damaging motor.
The relative position of each components and parts and connecting relation are seen Fig. 7 in the utility model.Voltage comparator M
1, M
2, M
3And M
4Be an integrated package altogether, for example can select LM339 for use; Voltage comparator M
5, M
6, M
7And M
8Be an integrated package altogether, also can select LM339 for use, operating voltage is provided through corresponding resistance by the output voltage E of power supply 7.Residual current protective unit 2 adopts known technologies, and with three-phase imbalance, phase-lacking protective unit 4 common voltage comparator M
4The overvoltage protection of overvoltage, under-voltage protection unit 5 is same as the prior art; Under-voltage protection is adjustable when voltage is produced as the 80%(that is lower than rated voltage when electric motor starting) execute protection; When motor rotation, line voltage is lower than 65% o'clock ability execute protection of rated value, i.e. the operating value of under-voltage protection is not changeless, but has the return difference value.M
7For the isolation of under-voltage protection unit is amplified.
Each unit of protector has wherein been selected integrated package LM7812 for use by power subsystem 7 power supplies.
Compared with prior art, the utility model has the following advantages:
1. can carry out protection to three-phase current unbalance, for example when the three-phase electricity flow valuve differed by more than 50%, protector can cut off motor power after time-delay in 2 seconds, can be used for the three phase electric machine of 5～500KW.
2. can be to motor overload, overcurrent execute protection. This protector can all detect the three-phase current of motor, and when arbitrary phase current surpassed the motor load current value, protector can both clock, and when the overcurrent time surpassed the limit that motor allows, protector just cut off motor power, and concrete data are as follows:
The load-rate of motor protector time delay time
700% 9 seconds
440% 41 seconds
300% 54 seconds
200% 1 minutes 22 seconds 8
150% 5 minutes 23 seconds
120% 14 minutes 36 seconds
110% 20 minutes 35 seconds 8
3. can be to connecting terminal of motor or coil short execute protection
When arbitrary phase current of motor three-phase current during greater than 8～10 times of motor rated current, protector can the instantaneous trip power supply, prevents that machine wire apparatus is on fire, avoids the generation of serious consequence.
4. can be to the motor rotation blockage execute protection
In the time can not rotating after the stuck energising of motor, protector can be after 3 seconds time-delay execute protection.
5. can be to motor phase shortage execute protection
When the motor vacant phase starting, protector energy instantaneous trip power supply; When motor phase shortage in service, execute protection action after can delaying time 1～2 second.
6. can execute protection when electrical network is under-voltage
When line voltage be lower than rated voltage 80% the time (adjustable during production), protector can self-locking, refusal is to the contactor energising, prevents that contactor from producing shake and burn;
When contactor adhesive, line voltage is not less than 65% o'clock of rated value, not execution error of protector action;
When line voltage be lower than rated value 65% the time, protector can execute protection.
7. electrical network overvoltage protection
Adjustable when line voltage surpasses the 115%(production of load voltage value), protector can the execute protection action.
8. earth leakage protective
When motor or device housings electrical leakage voltage during greater than 36 volts, this protector can moment execute protection action.
Claims (2)
1, a kind of electronic type three phase electric machine comprehensive protection device; comprise sampling unit 1, residual current protective unit 2, over-current protecting unit 3, three-phase imbalance, phase-lacking protective unit 4, overvoltage, under-voltage protection unit 5, performance element 6 and power supply 7, of the present utility model being characterised in that:
1) include three current transformer A, B, the C that respectively three-phase current is sampled in the sampling unit 1,
2) over-current protecting unit 3 comprises two voltage comparator M that reference voltage is different
1, M
2, reference voltage divider resistance R
17, R
16, R
7, R
8, signal voltage divider resistance R
23, R
24, charging capacitor Ct, two charging resistor R that resistance is different
T1, R
T2, isolated amplifier M
5With discharger R
11, D
12, M
1,
3) include detector 8, time-delay length and three-phase current unbalance degree activity delayer 9 and the isolated amplifier 10 that the while also is inversely proportional to the motor working current size that be inversely proportional in three-phase imbalance, the phase-lacking protective unit 4.
2, electronic type three phase electric machine comprehensive protection device as claimed in claim 1 is characterized in that said detector 8 is by voltage comparator M
3, sampled signal distributes resistance R
5, R
6, R
4With voltage stabilizing didoe DW
1Form, activity delayer 9 is by resistance R
12, R
21, R
14, diode D
9, D
15And capacitor C
3Form, isolated amplifier 10 is by voltage comparator M
4With diode D
7Form.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 89200446 CN2043798U (en) | 1989-01-14 | 1989-01-14 | Electronized multifunctional protector for three phase motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 89200446 CN2043798U (en) | 1989-01-14 | 1989-01-14 | Electronized multifunctional protector for three phase motor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2043798U true CN2043798U (en) | 1989-08-30 |
Family
ID=4858535
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 89200446 Expired - Lifetime CN2043798U (en) | 1989-01-14 | 1989-01-14 | Electronized multifunctional protector for three phase motor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2043798U (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101908754A (en) * | 2010-08-20 | 2010-12-08 | 三一重型装备有限公司 | High-voltage isolation protective circuit |
| CN102005727A (en) * | 2010-11-12 | 2011-04-06 | 煤炭科学研究总院重庆研究院 | Single motor protection device for dragging double motor through single frequency conversion |
| CN104882855A (en) * | 2015-06-15 | 2015-09-02 | 浙江德伦电气有限公司 | Comprehensive protector for intelligent motor |
| CN105680419A (en) * | 2016-03-09 | 2016-06-15 | 北京航空航天大学 | Motor stalling self-checking method for electric vehicle start-up process |
| CN106410753A (en) * | 2016-09-20 | 2017-02-15 | 珠海格力节能环保制冷技术研究中心有限公司 | Motor abnormality detection circuit and control method thereof |
-
1989
- 1989-01-14 CN CN 89200446 patent/CN2043798U/en not_active Expired - Lifetime
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101908754A (en) * | 2010-08-20 | 2010-12-08 | 三一重型装备有限公司 | High-voltage isolation protective circuit |
| CN101908754B (en) * | 2010-08-20 | 2013-01-02 | 三一重型装备有限公司 | High-voltage isolation protective circuit |
| CN102005727A (en) * | 2010-11-12 | 2011-04-06 | 煤炭科学研究总院重庆研究院 | Single motor protection device for dragging double motor through single frequency conversion |
| CN104882855A (en) * | 2015-06-15 | 2015-09-02 | 浙江德伦电气有限公司 | Comprehensive protector for intelligent motor |
| CN104882855B (en) * | 2015-06-15 | 2018-11-20 | 浙江德伦电气有限公司 | Intelligent electric machine comprehensive protection device |
| CN105680419A (en) * | 2016-03-09 | 2016-06-15 | 北京航空航天大学 | Motor stalling self-checking method for electric vehicle start-up process |
| CN106410753A (en) * | 2016-09-20 | 2017-02-15 | 珠海格力节能环保制冷技术研究中心有限公司 | Motor abnormality detection circuit and control method thereof |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN1018877B (en) | Solid-state trip apparatus comprise circuit of instantaneous trip independent of power voltage | |
| SE452823B (en) | Series capacitor EQUIPMENT | |
| CN1009786B (en) | Trip releaser with numerical solid state circuit auto-surveillance | |
| TW201310839A (en) | A DC chopper of doubly fed induction generator system and DC chopping method thereof | |
| CN1262802A (en) | Method and system for detecting shot-circuit in low-voltage mains | |
| CN1141767C (en) | Earthing protection method for small current earthing system | |
| CN107294135B (en) | Self-adaptive current protection method for power grid with distributed power supply access | |
| CN2043798U (en) | Electronized multifunctional protector for three phase motor | |
| EP0252493B1 (en) | Protective device for an electrical power line against its transient overvoltages | |
| CN115940081A (en) | Overvoltage protection device based on combination of multi-characteristic nonlinear resistance cards | |
| CN2308191Y (en) | Over voltage automtic power-off protection circuit | |
| CN213959736U (en) | Reliable heavy current protection circuit | |
| US20050083628A1 (en) | Close tolerance surge suppression circuit | |
| CN205986105U (en) | Circuit breaker zero -pressure time delay trip gear | |
| WO2010070403A1 (en) | An overvoltage protection assembly for medium voltage wind turbines | |
| WO1996013091A1 (en) | Transient suppressor for electronics systems | |
| CN1072294A (en) | Multi-function automatic monitor for power consumption | |
| CN202276154U (en) | Low voltage ride-through control device for double-fed wind power generation system | |
| RU194140U1 (en) | Surge protection device | |
| CN2355485Y (en) | Multifunctional three phase protection electronic switch | |
| CN2299377Y (en) | Explosion-proof device of lightning protector | |
| CN101340081B (en) | Electric protective method for electromagnetic forming machine | |
| CN2382128Y (en) | Breaker against electric leakage and fire | |
| CN2371713Y (en) | Induction motor protector | |
| CN2354283Y (en) | Motor protective switch |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C17 | Cessation of patent right | ||
| CX01 | Expiry of patent term |