CN110247387A - Servo-driven module with fault-tolerance - Google Patents
Servo-driven module with fault-tolerance Download PDFInfo
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- CN110247387A CN110247387A CN201910468627.2A CN201910468627A CN110247387A CN 110247387 A CN110247387 A CN 110247387A CN 201910468627 A CN201910468627 A CN 201910468627A CN 110247387 A CN110247387 A CN 110247387A
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- resistor
- servo
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- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02H—EMERGENCY PROTECTIVE CIRCUIT ARRANGEMENTS
- H02H11/00—Emergency protective circuit arrangements for preventing the switching-on in case an undesired electric working condition might result
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02P—CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- H02P25/00—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details
- H02P25/16—Arrangements or methods for the control of AC motors characterised by the kind of AC motor or by structural details characterised by the circuit arrangement or by the kind of wiring
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- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Rectifiers (AREA)
Abstract
The present invention provides a kind of servo-driven modules with fault-tolerance, including input port, servo unit main circuit, braking resistor port, output port, sampling control circuit and accessory power supply;Servo unit main circuit includes input EMI filter module, rectification module, soft start and braking circuit, main power module, first capacitor and the second capacitor;The input terminal of EMI filter module is connect with input port, and output end is connected with the input terminal of rectification module;The output end of rectification module and main power module are connected to P, N-terminal;Second capacitor is connected with the P of main power module, N-terminal;Soft start and braking circuit include first resistor and the first relay;One end of first resistor and one end of the first relay are connected to the end P, and the other end of first resistor is connect with the anode of the other end of the first relay and first capacitor;The negative terminal of first capacitor is connected to N-terminal.The access of the real power line of present invention energy is fault-tolerant, without damaging this module.
Description
Technical field
The present invention relates to Industry Control and automatic field more particularly to a kind of servo-driven modules with fault-tolerance.
Background technique
Servo-driven module on the market at present, generally use various fool proof connecting terminals and various marks standardize input and
The cut-in method of output power line, but during the rectification of production, aging and lathe, this method does not always evade operator
Carelessness, the wiring of operator's mistake causes servo drive circuit badly damaged, causes certain even irreversible damage
It loses.
Summary of the invention
The purpose of the present invention is to provide a kind of servo-driven modules with fault-tolerance, it is intended to for solving existing watch
The problem of circuit damages caused by taking drive module and not can avoid because of operator's wiring error.
The present invention is implemented as follows:
The present invention provides a kind of servo-driven module with fault-tolerance, including input port, servo unit main circuit, system
Dynamic resistance port, output port, sampling control circuit and accessory power supply;
The input of the servo unit main circuit is connected to the input port, and output is connected to the output port;Institute
Braking resistor port is stated to be connected with the servo unit main circuit;The input terminal of the sampling control circuit and auxiliary electricity
The output end in source connects, and output end and the servo unit main circuit are connected with each other;The accessory power supply and the servo unit
Main circuit interconnects;
The servo unit main circuit includes input EMI filter module, rectification module, soft start and braking circuit, main function
Rate module, first capacitor C1 and the second capacitor C2;The input terminal of the EMI filter module is connect with the input port, defeated
Outlet is connected with the input terminal of the rectification module;The output end of the rectification module is connected to the main power module
P, N-terminal;The second capacitor C2 is connected with P, the N-terminal of the main power module;The first capacitor C1 is electrolytic capacitor, institute
Stating the second capacitor C2 is high frequency capacitance;
The soft start and braking circuit include first resistor R1 and the first relay J1;One end of the first resistor R1
The end P, the other end of the other end of the first resistor R1 and the first relay J1 are connected to one end of the first relay J1
And the anode connection of first capacitor C1;The negative terminal of the first capacitor C1 is connected to N-terminal.
Further, the servo drive unit main circuit further includes first diode D1, the second diode D2, third electricity
Hinder R3, second resistance R2 and the first optocoupler U1;The anode of the first diode D1 and the second diode D2 are respectively connected to
The cathode of the end R1, S1 of rectification module input, the first diode D1 and the second diode D2 are simultaneously with 3rd resistor R3's
One end connection;Another input terminal for being connected to accessory power supply of the 3rd resistor R3;One end of the second resistance R2 with it is whole
The end the T1 connection of flow module input, another anode for being connected to the first optocoupler U1;The cathode and N-terminal of the first optocoupler U1 connects
It connects, collector meets power supply VCC, and emitter connects the input terminal of sampling control circuit.
Further, the soft start and braking circuit further include third diode D3 and the 7th power tube Q7;It is described
The cathode of third diode D3 is connected to the end BK1 of braking resistor port, and anode connects the anode of first capacitor C1;7th power
The source electrode of pipe Q7 connects N-terminal, and drain electrode connects the end BK2 of braking resistor port.
Compared with prior art, the invention has the following advantages:
The access of this servo-driven module with fault-tolerance provided by the invention, the real power line of energy is fault-tolerant, without
This module is damaged, non-standard operation is avoided and servo-driven module bring is damaged, and without adding too many device, is sufficiently sent out
It has waved that circuit structure is simple, the simple advantage of control circuit, has not needed to reduce costs, especially using the fool proof terminal special procured
It is applicable in the existing servo-driven module of substitution.
Detailed description of the invention
Fig. 1 is a kind of block diagram of the servo-driven module with fault-tolerance provided in an embodiment of the present invention;
Fig. 2 is a kind of circuit diagram of the servo-driven module with fault-tolerance provided in an embodiment of the present invention;
Fig. 3 is the circuit diagram of conventional servo-driven module.
Specific embodiment
Following will be combined with the drawings in the embodiments of the present invention, and technical solution in the embodiment of the present invention carries out clear, complete
Site preparation description, it is clear that described embodiments are only a part of the embodiments of the present invention, instead of all the embodiments.It is based on
Embodiment in the present invention, it is obtained by those of ordinary skill in the art without making creative efforts all other
Embodiment shall fall within the protection scope of the present invention.
As shown in Figure 1, the embodiment of the present invention provides a kind of servo-driven module with fault-tolerance, including input (R, S,
T) port 11, servo unit main circuit 13, braking resistor port (BK1, BK2) 12, output port (U, V, W) 14, controlling of sampling
Circuit 15 and accessory power supply 16;The input of the servo unit main circuit 13 is connected to the input port 11, output termination
To the output port 14, for realizing the transmitting and conversion of energy;The braking resistor port 12 is used for external braking resistor,
It is connected with the servo unit main circuit 13, is let out by the brake pipe in external braking resistor and servo unit main circuit 13
Put P, the braking energy of N bus;The full name of the sampling control circuit 15 is to sample & logic control, display and interface circuit,
Input terminal is connect with the output end of the accessory power supply 16, output end and the servo unit main circuit 13 and external servo motor
It is connected with each other, for receiving the sampling and feedback signal of servo unit main circuit 13 and external servo motor, and issues control letter
Number give servo unit main circuit 13, control the operation of servo motor;The accessory power supply 16 and the servo unit main circuit 13
It interconnects, for powering and realizing the fault-tolerant processing to external power line cable.
Specifically, as shown in Fig. 2, the servo unit main circuit 13 include input EMI filter module 7, rectification module 8,
Soft start and braking circuit 9, main power module 10, first capacitor C1 and the second capacitor C2;The EMI filter module 7 it is defeated
Enter end to connect with the input port 11, output end is connected with the input terminal of the rectification module 8;The rectification module 8
Output end and the main power module 10 are connected to P, N-terminal, and the main power module 10 is IGBT, IPM or MOS module list
Member;The second capacitor C2 is connected with P, the N-terminal of the main power module 10;The first capacitor C1 is the electrolysis of large capacity
Capacitor, can be multiple capacitor series, parallel and series-parallel combination, and the second capacitor C2 is high frequency capacitance.
The soft start and braking circuit 9 include first resistor R1, the first relay J1, third diode D3, the eight or three
Grade pipe Q8 and the 7th power tube Q7;One end of the first resistor R1 and one end of the first relay J1 are connected to the end P, institute
The other end for stating first resistor R1 is connect with the anode of the other end of the first relay J1 and first capacitor C1;The first capacitor
The negative terminal of C1 is connected to N-terminal;One end 1 of the line packet of the first relay J1 meets power supply VCC1, and the other end 2 of line packet connects the eight or three
The collector of grade pipe Q8, the emitter of the 8th triode Q8 connect N-terminal.
Through the above scheme, it if the power line for the 220V or 380V sum that will enter into the end R, S, T is connected to the end U, V, W, and incites somebody to action
U, the cable that the power line at the end V, W is connected to motor originally is connected to the end R, S, T, and at this moment 220V or 380V voltage passes through main power module
10 built-in diode rectification, the voltage after rectification are applied directly to P, N-terminal and the both ends C2 all the way, and C2 is high frequency capacitance, input electricity
Press the surge current very little that is formed to C2, another way slowly gives C1 charging by soft start resistance R1, on this when C2
Charging current is limited by R1, will not form excessively high dash current, therefore misconnection will not damage circuit.
Preferably, the soft start and braking circuit 9 further include third diode D3;The cathode of the third diode D3
It is connected to the end BK1 of braking resistor port 12, anode connects the anode of first capacitor C1;The source electrode of the 7th power tube Q7 connects N-terminal,
Drain electrode connects the end BK2 of braking resistor port 12.If by the power line misconnection at the end T to the end BK1, when the end BK1 is exchange positive half cycle
D3 is reversely by preventing from damaging circuit.
Optimize above-described embodiment, the servo drive unit main circuit 13 further includes first diode D1, the second diode
D2,3rd resistor R3, second resistance R2 and the first optocoupler U1;The anode of the first diode D1 and the second diode D2
It is respectively connected to the end R1, S1 of the input of rectification module 8, the cathode while and third of the first diode D1 and the second diode D2
One end of resistance R3 connects;Another input terminal for being connected to accessory power supply 16 of the 3rd resistor R3;The second resistance R2
One end connect with the end T1 that rectification module 8 inputs, another anode for being connected to the first optocoupler U1;The yin of the first optocoupler U1
Pole is connect with N-terminal, and collector meets power supply VCC, and emitter connects the input terminal of sampling control circuit 15.
In above scheme, the power line signal at second resistance R2 and the first optocoupler U1 detection end T, by optocoupler side by signal
It is transmitted to sampling control circuit 15, the power line at the only end R, S, T correctly accesses, and sampling control circuit 15 just issues signal control
Q8 conducting in soft start and braking circuit 9 processed, is closed relay J1, completes Soft Start-up Process, circuit enters standby mode.
First diode D1, the second diode end D2,3rd resistor R3 can be used as the enabling signal of accessory power supply 16, in the port R, S
Power line correctly access in the case where, accessory power supply 16 starts to work normally.Therefore above scheme can further prevent mistake
Pair of connecting wires circuit damages.
The operation principle of the present invention is that:
The power line at the correct connection end R, S, T, the end BK1, BK2 and the end U, V, W, closes the connection between connection power cable
The alternating voltage of switch, input 220 or 380 accesses the end R, S, T, through input EMI filter module 7 and rectification module 8, after rectification
Voltage-drop loading to P, N-terminal slowly charges through R1 to C1 all the way, and another way is fed directly to the input of C2 and main power module 10
End, on the other hand, the alternating voltage at the end R1, S1 constitute electricity by the built-in diode inside rectification module 8 by D1, D2, R3
It flows back to road and provides enough starting voltage and currents to accessory power supply 16, accessory power supply 16 starts normally to start, and gives other electricity
Road provides required normal voltage, and the alternating voltage at the end T1 that rectification module 8 inputs is by two built in R2, U1 and rectification module 8
The circuit that pole pipe is formed, and signal is passed to sampling control circuit 15 by optocoupler side by the AC signal that will test the end T1,
Sampling control circuit 15 detects P, after the signal of N busbar voltage and optocoupler side, export all the way signal to soft start and braking electricity
Road 9 controls the conducting of Q8 pipe, and 3,4 ends of relay J1 are attracted, and soft start is completed, and complete machine enters standby mode.
Several situations of lower surface analysis power line misconnection and misconnection:
If the power line for the 220V or 380V sum that 1, will enter into the end R, S, T is connected to the end U, V, W, and by the dynamic of the end U, V, W
The cable that the line of force is connected to motor originally is connected to the end R, S, T, since the starting of accessory power supply 16 is by detecting 220V or 380V Lai complete
At starting work, thus relay J1 in the whole process when off-state, at this moment 220V or 380V voltage passes through main power
The built-in diode of module 10 rectifies, and the voltage after rectification is applied directly to P, N-terminal and the both ends C2 all the way, and C2 is high frequency capacitance, defeated
Enter the surge current very little that voltage forms C2, another way slowly gives C1 charging by soft start resistance R1, this when C2
On charging stream limited by R1, excessively high dash current will not be formed, misconnection will not damage circuit, restore correct
Wiring.
If the wherein single line in the power line for the 220V or 380V sum that 2, will enter into the end R, S, T is connected to the end BK1, BK2
And any end at the end U, V, W, it is assumed here that by the power line misconnection at the end T to the end BK1, the D3 when the end BK1 is exchange positive half cycle
Reversely by when the end BK1 is exchange negative half period, alternating voltage passes through diode-built-in, the end P, R1 and the second level of rectification module 8
Pipe D3 halfwave rectifier is back to the end BK1, resistance R3 fever, and at this moment accessory power supply 16 gets the voltage through the end R1, S1 and normal work
Make, while supply voltage needed for other circuits are provided, due to wiring error, optocoupler U1 does not detect the voltage signal at the end T1,
Therefore relay J1 is not attracted, and sampling control circuit 15 exports alarm signal.
It compared to the servo-driven module circuit of Fig. 3 routine, works in the first situation, alternating voltage 220V or 380V are logical
The built-in diode rectification crossed in main power module directly acts on P, and N-terminal, due to C1, C2 directly simultaneously P, N-terminal certainly will be to main function
Rate module causes very big surge current, causes the protective device in power grid to have trip operation, or directly damage in this unit
Device;Second situation, since the start-up resistor of accessory power supply connects at the end P, at this moment power supply is worked normally, relay J1 closure,
The built-in diode of C1, C2 capacitor and rectification module of the alternating voltage at the end BK1 by D1 and parallel connection returns to the end R, S, T and is formed back
Road causes to have biggish dash current in circuit and burn D1 due to the electrolytic capacitor that C1 is large capacity.
Therefore, this servo-driven module with fault-tolerance provided in an embodiment of the present invention, the real power line of energy connect
Enter fault-tolerant, without damaging this module, avoids non-standard operation and servo-driven module bring is damaged, and is too many without addition
Device, has given full play to that circuit structure is simple, the simple advantage of control circuit, does not need to reduce using the fool proof terminal special procured
Cost, the particularly suitable existing servo-driven module of substitution.
The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the invention, all in essence of the invention
Within mind and principle, any modification, equivalent replacement, improvement and so on be should all be included in the protection scope of the present invention.
Claims (3)
1. a kind of servo-driven module with fault-tolerance, it is characterised in that: including input port, servo unit main circuit, system
Dynamic resistance port, output port, sampling control circuit and accessory power supply;
The input of the servo unit main circuit is connected to the input port, and output is connected to the output port;The system
Dynamic resistance port is connected with the servo unit main circuit;The input terminal of the sampling control circuit and the accessory power supply
Output end connection, output end and the servo unit main circuit are connected with each other;The accessory power supply and the main electricity of the servo unit
Road interconnects;
The servo unit main circuit includes input EMI filter module, rectification module, soft start and braking circuit, main power mould
Block, first capacitor C1 and the second capacitor C2;The input terminal of the EMI filter module is connect with the input port, output end
It is connected with the input terminal of the rectification module;The output end of the rectification module and the main power module are connected to P, N
End;The second capacitor C2 is connected with P, the N-terminal of the main power module;The first capacitor C1 is electrolytic capacitor, described
Second capacitor C2 is high frequency capacitance;
The soft start and braking circuit include first resistor R1 and the first relay J1;One end of the first resistor R1 and the
One end of one relay J1 is connected to the end P, the other end and of the other end of the first resistor R1 and the first relay J1
The anode of one capacitor C1 connects;The negative terminal of the first capacitor C1 is connected to N-terminal.
2. as described in claim 1 with the servo-driven module of fault-tolerance, it is characterised in that: the servo drive unit master
Circuit further includes first diode D1, the second diode D2,3rd resistor R3, second resistance R2 and the first optocoupler U1;It is described
The first diode D1 and the second diode D2 anode be respectively connected to rectification module input the end R1, S1, the one or two pole
The cathode of pipe D1 and the second diode D2 are connect with one end of 3rd resistor R3 simultaneously;Described the another of 3rd resistor R3 is connected to
The input terminal of accessory power supply;One end of the second resistance R2 is connect with the end T1 that rectification module inputs, another to be connected to first
The anode of optocoupler U1;The cathode of the first optocoupler U1 is connect with N-terminal, and collector meets power supply VCC, and emitter connects controlling of sampling electricity
The input terminal on road.
3. as described in claim 1 with the servo-driven module of fault-tolerance, it is characterised in that: the soft start and braking electricity
Road further includes third diode D3 and the 7th power tube Q7;The cathode of the third diode D3 is connected to braking resistor port
The end BK1, anode connect the anode of first capacitor C1;The source electrode of the 7th power tube Q7 connects N-terminal, and drain electrode connects braking resistor port
The end BK2.
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CN201910468627.2A CN110247387B (en) | 2019-05-31 | 2019-05-31 | Servo driving module with fault tolerance |
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CN201910468627.2A CN110247387B (en) | 2019-05-31 | 2019-05-31 | Servo driving module with fault tolerance |
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CN110247387B CN110247387B (en) | 2021-03-16 |
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Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113541122A (en) * | 2021-07-20 | 2021-10-22 | 珠海格力电器股份有限公司 | Protection device and method for servo driver and servo motor |
Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN2753054Y (en) * | 2004-08-20 | 2006-01-18 | 庹建国 | AC drive with protection against miswiring |
CN2805210Y (en) * | 2005-03-16 | 2006-08-09 | 刘文辉 | Main circuit for high energy feed back type electronic loading device |
CN201838994U (en) * | 2010-06-18 | 2011-05-18 | 北京茨浮电气有限公司 | Input and output reverse protection device of frequency converter |
CN102280862A (en) * | 2011-08-26 | 2011-12-14 | 广州三晶电气有限公司 | Frequency converter input/output reverse connection detection protection method and device |
CN203675031U (en) * | 2014-01-22 | 2014-06-25 | 浙江禾川科技股份有限公司 | Frequency converter motor drive circuit and frequency converter |
EP3336994A1 (en) * | 2016-12-01 | 2018-06-20 | Camlin Technologies Limited | Circuit protection apparatus with auxiliary switch device |
CN208337441U (en) * | 2018-06-15 | 2019-01-04 | 广东石油化工学院 | A kind of servo-driver with multi-stage protection |
CN109417286A (en) * | 2017-06-28 | 2019-03-01 | 深圳配天智能技术研究院有限公司 | A kind of detection circuit and servo-driver of servo-driver |
-
2019
- 2019-05-31 CN CN201910468627.2A patent/CN110247387B/en active Active
Patent Citations (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN2753054Y (en) * | 2004-08-20 | 2006-01-18 | 庹建国 | AC drive with protection against miswiring |
CN2805210Y (en) * | 2005-03-16 | 2006-08-09 | 刘文辉 | Main circuit for high energy feed back type electronic loading device |
CN201838994U (en) * | 2010-06-18 | 2011-05-18 | 北京茨浮电气有限公司 | Input and output reverse protection device of frequency converter |
CN102280862A (en) * | 2011-08-26 | 2011-12-14 | 广州三晶电气有限公司 | Frequency converter input/output reverse connection detection protection method and device |
CN203675031U (en) * | 2014-01-22 | 2014-06-25 | 浙江禾川科技股份有限公司 | Frequency converter motor drive circuit and frequency converter |
EP3336994A1 (en) * | 2016-12-01 | 2018-06-20 | Camlin Technologies Limited | Circuit protection apparatus with auxiliary switch device |
CN109417286A (en) * | 2017-06-28 | 2019-03-01 | 深圳配天智能技术研究院有限公司 | A kind of detection circuit and servo-driver of servo-driver |
CN208337441U (en) * | 2018-06-15 | 2019-01-04 | 广东石油化工学院 | A kind of servo-driver with multi-stage protection |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN113541122A (en) * | 2021-07-20 | 2021-10-22 | 珠海格力电器股份有限公司 | Protection device and method for servo driver and servo motor |
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