CN201742080U - Frequency converter differential input overcurrent protection circuit for centrifugal machine - Google Patents
Frequency converter differential input overcurrent protection circuit for centrifugal machine Download PDFInfo
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- CN201742080U CN201742080U CN2010201788828U CN201020178882U CN201742080U CN 201742080 U CN201742080 U CN 201742080U CN 2010201788828 U CN2010201788828 U CN 2010201788828U CN 201020178882 U CN201020178882 U CN 201020178882U CN 201742080 U CN201742080 U CN 201742080U
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Abstract
The utility model discloses a frequency converter differential input overcurrent protection circuit for a centrifugal machine, which is simple, realizes double protection for hardware and software, meets the reliable requirements of safety and stability on the centrifugal machine, and avoids the safety hazard for error protection due to interference of the circuit. The differential input overcurrent protection circuit consists of a current sampling resistor R, resistors R1-R5, an operational amplifier U1 and a comparator U2; an IGBT (Insulated Gate Bipolar Transistor) three-phase driver is used for realizing hardware protection, a controller is used for realizing software protection; and the specific steps are as follows: when an overcurrent signal occurs, high level is converted into low level, the controller carries out software protection when receiving the overcurrent signal, and the overcurrent signal end of the IGBT three-phase driver receives the overcurrent signal for carrying out hardware protection. The differential input overcurrent protection circuit is low in cost, fast in responding speed, and can effectively filter common-mode noise, thus reducing circuit disturbance and improving the reliability of a frequency converter.
Description
Technical field
The utility model relates to a kind of centrifuge with frequency converter difference input current foldback circuit, and particularly each components and parts prevents owing to short circuit produces overcurrent in the frequency converter used of protection centrifuge or the Switching Power Supply.
Background technology
In traditional circuit engineering field, current foldback circuit is a kind of a kind of circuit that can protect entire circuit under the excessive situation of the electric current of flowing through.
Please refer to Fig. 1; this figure is existing current foldback circuit structure chart; comprise that one can connect the inverter circuit 2 with IGBT to the three phase alternating current motor 1 of inverter circuit power supply; the controller 3 that can produce pwm signal transmits pwm signal and gives the IGBT three-phase drive device 4 that can drive IGBT; this IGBT three-phase drive device 4 transmits pwm signal and gives inverter circuit 2; the output of described inverter circuit 2 is divided into two-way; lead up to current sampling resistor R ground connection; another road connects the negative input end of amplifier U1 by first resistance R 1; the positive input terminal ground connection of this amplifier U1; serial connection second resistance R 2 between the negative input end of amplifier U1 and output; and the output of amplifier U1 connects the negative input end of the second comparator U2; the positive input terminal of described comparator U2 is divided into two-way; the 3rd resistance of leading up to meets power supply VCC, leads up to the 4th resistance R 4 ground connection, and the output of described comparator U2 is divided into two-way; one the tunnel connects the fault input of IGBT three-phase drive device 4, and another road connects controller 3 by a reverser.
In existing current foldback circuit, with current sampling resistor R sample rate current, U1 amplifies current signal by amplifier, compare by overcurrent threshold voltage with comparator U2, if current signal is more than or equal to the overcurrent threshold voltage, then the output overcurrent signal is delivered to over-current signal the fault input of IGBT three-phase drive device this moment on the one hand, turn-off 6 tunnel pulses output of PWM2, carry out hardware protection; On the other hand over-current signal is delivered to MCU, turn-off 6 tunnel pulses output of PWM1, carry out software protection.
This circuit defect is: the common-mode noise on can not filtering current sampling resistor R, and noise can be exaggerated, when the voltage amplification of noise to surpassing the overcurrent threshold voltage, and newspaper over-current signal, thereby will increase the probability of wrong report over-current signal, and cause centrifuge to have hidden danger with the reliability of frequency converter.
The utility model content
Technical problem to be solved in the utility model is to provide a kind of centrifuge to import current foldback circuit with the frequency converter difference at the existing many technical problems of existing current foldback circuit; can effectively suppress null offset and improve common-mode rejection ratio; and can effectively filtering common-mode noise; disturb thereby reduce circuit, improve the reliability of frequency converter.
In order to realize the foregoing invention purpose, the technical scheme that the utility model adopted is:
A kind of centrifuge is imported current foldback circuit with the frequency converter difference; comprise that one can connect the inverter circuit with IGBT to the three phase alternating current motor of inverter circuit power supply; the controller that can produce pwm signal transmits pwm signal and gives the IGBT three-phase drive device that can drive IGBT; this IGBT three-phase drive device transmits pwm signal and gives inverter circuit; the output of described inverter circuit is divided into two-way; one the tunnel connects an end of current sampling resistor; another road connects the negative input end of described amplifier by first resistance; serial connection second resistance between the negative input end of amplifier and output; the output of described amplifier connects the negative input end of described comparator; the positive input terminal of described comparator is divided into two-way; the 3rd resistance of leading up to connects power supply; lead up to the 4th grounding through resistance; the output of described comparator is divided into two-way; one the tunnel connects the fault input of IGBT three-phase drive device; another road is by a reverser access controller; it is characterized in that; the other end of described current sampling resistor is divided into two-way; one tunnel ground connection, another road connect the positive input terminal of first amplifier by the 5th resistance.
Further being characterized as described controller is the MCU controller.
Description of drawings
Fig. 1 is existing current foldback circuit structure chart.
Fig. 2 is a circuit structure diagram of the present utility model.
Embodiment
In order to make technological means of the present utility model, creation characteristic, to reach purpose and effect is easy to understand, the utility model is further elaborated below in conjunction with embodiment.
As shown in Figure 2; a kind of centrifuge is imported current foldback circuit with the frequency converter difference; comprise that one can connect the inverter circuit 2 with IGBT to the three phase alternating current motor 1 of inverter circuit power supply; the controller 3 that can produce pwm signal transmits pwm signal and gives the IGBT three-phase drive device 4 that can drive IGBT; this IGBT three-phase drive device 4 transmits pwm signal and gives inverter circuit 2; the output of described inverter circuit 2 is divided into two-way; one the tunnel connects the end of current sampling resistor R; another road connects the negative input end of amplifier U1 by first resistance R 1; the other end of described current sampling resistor R is divided into two-way; one tunnel ground connection; another road connects the positive input terminal of amplifier U1 by the 5th resistance R 5; serial connection second resistance R 2 between the negative input end of amplifier U1 and output; and the output of amplifier U1 connects the negative input end of comparator U2; the positive input terminal of described comparator U2 is divided into two-way; the 3rd resistance R 3 of leading up to meets power supply VCC; lead up to the 4th resistance R 4 ground connection; the output of described comparator U2 is divided into two-way; one the tunnel connects the fault input of IGBT three-phase drive device 4, and another road connects controller 3 by a reverser.
At the circuit middle controller is the MCU controller.
Current sampling resistor R among Fig. 2, resistance R 1, R2, R3, R4, R5 and amplifier U1 and comparator U2 constitute difference input current foldback circuit, wherein resistance R 3, R4 provides the overcurrent protection threshold value, the difference input can effectively suppress null offset and improve common-mode rejection ratio, and can effectively filtering common-mode noise, thereby reducing circuit disturbs, it is characterized in that the input of current sampling signal Vin1 and Vin2 difference, U1 is enlarged into Vin3 with over-current signal by amplifier, Vin3 and Vref compare, when over-current phenomenon avoidance not occurring, Vin3＜Vref, Vout exports high level, when over-current phenomenon avoidance occurring, Vin3＞Vref, Vout becomes low level (Vout=0V) by high level, over-current signal Vout is delivered to the overcurrent protection end of three-phase inversion driver, cut off the output of three-phase drive device drive signal, realize hardware protection; Simultaneously, overcurrent protection signal Vout delivers to MCU through reverser, and MCU receives overcurrent protection signal (Vout=0), realizes software protection thereby turn-off the output of six road pwm pulses, and the utility model is anti-interference strong, and response speed is fast, reliability is high.
More than show and described basic principle of the present utility model and principal character and advantage of the present utility model.The technical staff of the industry should understand; the utility model is not restricted to the described embodiments; that describes in the foregoing description and the specification just illustrates principle of the present utility model; under the prerequisite that does not break away from the utility model spirit and scope; the utility model also has various changes and modifications; these changes and improvements all fall in claimed the utility model scope, and the claimed scope of the utility model is defined by appending claims and equivalent thereof.
Claims (2)
1. a centrifuge is imported current foldback circuit with the frequency converter difference; comprising can be by the three phase alternating current motor of inverter circuit power supply; the inverter circuit that connection is made up of IGBT; can produce the controller of pwm signal; transmit pwm signal and give the IGBT three-phase drive device that can drive IGBT; this IGBT three-phase drive device transmits pwm signal and gives inverter circuit; the output of described inverter circuit is divided into two-way; one the tunnel connects an end of current sampling resistor; another road connects the negative input end of amplifier U1 by resistance R 1; connecting resistance R2 between the negative input end of amplifier U1 and output; the output of described amplifier U1 connects the negative input end of comparator U2; the positive input terminal of described comparator U2 is divided into two-way; the resistance R 3 of leading up to connects power supply; lead up to resistance R 4 ground connection; the output of described comparator U2 is divided into two-way; one the tunnel connects the fault input of IGBT three-phase drive device; another road is by a reverser access controller; it is characterized in that; the other end of described current sampling resistor is divided into two-way; one tunnel ground connection, another road connect the positive input terminal of amplifier U1 by resistance R 5.
2. a kind of centrifuge according to claim 1 is characterized in that with frequency converter difference input current foldback circuit described controller is the MCU controller.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010201788828U CN201742080U (en) | 2010-04-28 | 2010-04-28 | Frequency converter differential input overcurrent protection circuit for centrifugal machine |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010201788828U CN201742080U (en) | 2010-04-28 | 2010-04-28 | Frequency converter differential input overcurrent protection circuit for centrifugal machine |
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| Publication Number | Publication Date |
|---|---|
| CN201742080U true CN201742080U (en) | 2011-02-09 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN2010201788828U Expired - Fee Related CN201742080U (en) | 2010-04-28 | 2010-04-28 | Frequency converter differential input overcurrent protection circuit for centrifugal machine |
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| CN (1) | CN201742080U (en) |
Cited By (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102629751A (en) * | 2012-04-26 | 2012-08-08 | 深圳市汉拓数码有限公司 | Over-current protection circuit |
| CN102858049A (en) * | 2011-06-30 | 2013-01-02 | 海洋王照明科技股份有限公司 | Over-current protection sampling circuit, light-emitting diode (LED) drive circuit and LED lamp |
| CN106130331A (en) * | 2016-06-28 | 2016-11-16 | 中车青岛四方车辆研究所有限公司 | Rail vehicle accessory power supply short-circuit protection and guard method |
| CN109672147A (en) * | 2019-02-19 | 2019-04-23 | 国电南瑞科技股份有限公司 | A kind of fast current protection method of Thyristor Current Source type convertor circuit |
| CN109921384A (en) * | 2019-03-21 | 2019-06-21 | 惠州市蓝微电子有限公司 | A kind of brushless electric machine starting short-circuit detecting circuit and detection method |
| CN109950877A (en) * | 2019-04-24 | 2019-06-28 | 苏州易德龙科技股份有限公司 | A kind of three-phase motor driver overcurrent protective device |
| CN110369160A (en) * | 2019-06-25 | 2019-10-25 | 深圳市四方电气技术有限公司 | Centrifuge driver protects circuit |
| CN110854811A (en) * | 2018-08-21 | 2020-02-28 | 南京德朔实业有限公司 | Electric tool |
-
2010
- 2010-04-28 CN CN2010201788828U patent/CN201742080U/en not_active Expired - Fee Related
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102858049A (en) * | 2011-06-30 | 2013-01-02 | 海洋王照明科技股份有限公司 | Over-current protection sampling circuit, light-emitting diode (LED) drive circuit and LED lamp |
| CN102858049B (en) * | 2011-06-30 | 2015-02-18 | 海洋王照明科技股份有限公司 | Over-current protection sampling circuit, light-emitting diode (LED) drive circuit and LED lamp |
| CN102629751A (en) * | 2012-04-26 | 2012-08-08 | 深圳市汉拓数码有限公司 | Over-current protection circuit |
| CN102629751B (en) * | 2012-04-26 | 2015-05-13 | 深圳市汉拓数码有限公司 | Over-current protection circuit |
| CN106130331B (en) * | 2016-06-28 | 2019-06-18 | 中车青岛四方车辆研究所有限公司 | Rail vehicle accessory power supply short-circuit protection and guard method |
| CN106130331A (en) * | 2016-06-28 | 2016-11-16 | 中车青岛四方车辆研究所有限公司 | Rail vehicle accessory power supply short-circuit protection and guard method |
| CN110854811A (en) * | 2018-08-21 | 2020-02-28 | 南京德朔实业有限公司 | Electric tool |
| CN109672147A (en) * | 2019-02-19 | 2019-04-23 | 国电南瑞科技股份有限公司 | A kind of fast current protection method of Thyristor Current Source type convertor circuit |
| CN109672147B (en) * | 2019-02-19 | 2019-09-24 | 国电南瑞科技股份有限公司 | A kind of fast current protection method of Thyristor Current Source type convertor circuit |
| CN109921384A (en) * | 2019-03-21 | 2019-06-21 | 惠州市蓝微电子有限公司 | A kind of brushless electric machine starting short-circuit detecting circuit and detection method |
| CN109950877A (en) * | 2019-04-24 | 2019-06-28 | 苏州易德龙科技股份有限公司 | A kind of three-phase motor driver overcurrent protective device |
| CN110369160A (en) * | 2019-06-25 | 2019-10-25 | 深圳市四方电气技术有限公司 | Centrifuge driver protects circuit |
| CN110369160B (en) * | 2019-06-25 | 2021-07-30 | 深圳市四方电气技术有限公司 | Centrifuge driver protection circuit |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20110209 Termination date: 20190428 |
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| CF01 | Termination of patent right due to non-payment of annual fee |