CN201781265U - Motor differential protection device - Google Patents
Motor differential protection device Download PDFInfo
- Publication number
- CN201781265U CN201781265U CN2010205125087U CN201020512508U CN201781265U CN 201781265 U CN201781265 U CN 201781265U CN 2010205125087 U CN2010205125087 U CN 2010205125087U CN 201020512508 U CN201020512508 U CN 201020512508U CN 201781265 U CN201781265 U CN 201781265U
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- motor
- differential protection
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- circuit
- motor differential
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Abstract
A motor differential protection device mainly resolves the problem that the existing motor differential protector is instable in operation, and is characterized in that the motor differential protection device further comprises a low-pass filter loop unit, the low-pass filter loop unit is connected among current signal output ends of end sides and a neutral point side of a motor and an input end of a differential AD sampling loop, the low-pass filter loop unit receives current signals output from the current signal output ends of the end sides and the neutral point side of the motor, and after high-frequency harmonic waves are filtered, low-frequency current sampling signals are output to the differential AD sampling loop. The motor differential protection device is added with a low-pass filter loop unit and a photoelectric isolating circuit on the basis of an original structure, higher harmonics in the sampled current signals are filtered and a CPU system is not directly electrically connected with external control electrical equipment, so that stability of the motor differential protection device is increased and service life thereof is prolonged.
Description
Technical field:
The utility model relates to the motor protecting device of using in a kind of oil field operation field, specifically, relates to a kind of electrical control gear that can realize the motor differential protection.
Background technology:
At present on the oil field, most oil pumper all has been equipped with the motor differential protection, operation through the long period, find that existing motor differential protection can realize the protective effect to motor substantially when current imbalance, but equally also there are the following problems: at first, current signal distolateral by the machine of motor and that neutral point side is adopted all contains high order harmonic component, make follow-up difference AD sampling circuit and cpu system that the fault of distortion easily takes place thus, cause the protective device fluctuation of service; Secondly; existing motor differential protection directly inserts cpu system with the switching value input circuit of external control electric equipment; in case external control electric equipment generation overcurrent or accidents such as short circuit, ground connection; can directly cause electric infringement, reduce the useful life of this kind device the CPU in the protective device.
The utility model content:
The technical problem of mentioning in order to solve in the background technology; the utility model provides a kind of motor differential protection; this kind motor differential protection has increased a low-pass filtering circuit units and a photoelectric isolating circuit on the basis of original structure; realized thus that high order harmonic component in the sample rate current signal is filtered out and cpu system and external control electric equipment between no longer for directly being electrically connected; thus, the stability and the useful life of the operation of motor differential protection have been improved.
The technical solution of the utility model is: this kind motor differential protection; comprise a difference AD sampling circuit that can receive the distolateral and neutral point side current signal of motor machine; cpu system; the switching value input circuit; the relay logic loop; human-machine interface module and power module; it is characterized in that: described motor differential protection also comprises a low-pass filtering circuit units; described low-pass filtering circuit units is connected between the input of motor machine distolateral and neutral point side current signal output end and described difference AD sampling circuit; described low-pass filtering circuit units receives and comes from the current signal that described motor machine is distolateral and the neutral point side current signal output end is exported; behind the filtering high-frequency harmonic, to the current sampling signal of described difference AD sampling circuit output low frequency.
In addition; for realizing the electrical isolation between cpu system and the external control electric equipment; be provided with the photoelectric isolating circuit that comprises luminous tube and photodiode in described motor differential protection between switching value input circuit and cpu system, the switching signal of described switching value input circuit output outputs to the switching value signal input part of described cpu system by the optocoupler effect of photoelectric isolating circuit.
When finishing such scheme, preferred described low-pass filtering circuit units adopts the Butterworth LPF chip, and described photoelectric isolating circuit adopts linear optical coupling HCNR200 chip.
The utlity model has following beneficial effect: the described motor differential protection of this kind is owing to set up a low-pass filtering circuit units between the input of and neutral point side current signal output end and described difference AD sampling circuit distolateral at the motor machine; by this low-pass filtering circuit units the current signal that comes from motor is carried out low-pass filtering; You Hai high order harmonic component just can be filtered and only be kept the useful electric current of low frequency like this, and difference AD sampling circuit and the cpu system in the protective device just the problem of distortion can not occur again like this.In addition; in described motor differential protection, between switching value input circuit and cpu system, be provided with the photoelectric isolating circuit that comprises luminous tube and photodiode; the switching signal of described switching value input circuit output outputs to the switching value signal input part of described cpu system by the optocoupler effect of photoelectric isolating circuit; like this; just can realize the electrical isolation between cpu system and the external control electric equipment, guarantee the safe and reliable work of cpu system.
Description of drawings:
Fig. 1 is a composition schematic diagram of the present utility model.
Embodiment:
The utility model is described in further detail below in conjunction with accompanying drawing:
By shown in Figure 1; this kind motor differential protection; comprise a difference AD sampling circuit that can receive the distolateral and neutral point side current signal of motor machine; cpu system; the switching value input circuit; the relay logic loop; conventional structure such as human-machine interface module and power module; its unique distinction is: described motor differential protection also comprises a low-pass filtering circuit units; described low-pass filtering circuit units is connected between the input of motor machine distolateral and neutral point side current signal output end and described difference AD sampling circuit; described low-pass filtering circuit units receives and comes from the current signal that described motor machine is distolateral and the neutral point side current signal output end is exported; behind the filtering high-frequency harmonic, to the current sampling signal of described difference AD sampling circuit output low frequency.
In addition; be provided with the photoelectric isolating circuit that comprises luminous tube and photodiode in described motor differential protection between switching value input circuit and cpu system, the switching signal of described switching value input circuit output outputs to the switching value signal input part of described cpu system by the optocoupler effect of photoelectric isolating circuit.
During concrete enforcement, described low-pass filtering circuit units adopts the Butterworth LPF chip, and described photoelectric isolating circuit adopts linear optical coupling HCNR200 chip.HCNR200 molded lines optocoupler is made up of light-emitting diode, feedback light electric diode and output photodiode.When light-emitting diode passes through drive current, send infrared light as servo luminous flux.This light is radiated at respectively on feedback light electric diode and the output photodiode, and the feedback light electric diode absorbs the part of feedback light electric diode luminous flux, thereby produces Control current.The linear ratio of servo luminous flux that output current that the output photodiode produces and light-emitting diode send.The signal that HCNR200 is operated under the photoconductive pattern is the positive polarity input, positive polarity output.Need the size of the elementary amplifier input bias current of resistance adjustment in the buffer circuit, electric capacity plays feedback effect, filtering simultaneously the burr signal in the circuit, avoid the aluminum gallium arsenide light-emitting diode of HCNR200 to be subjected to unexpected impact.
In addition, the signal of switching value input circuit input cpu system, cpu system is provided with three tunnel outputs, connects communication module, human-machine interface module MMI and relay logic loop and power module respectively.And also can be provided with photoelectric isolating circuit between cpu system and the relay logic loop, act on identical with the former.In addition, communication module comprises ethernet communication interface, CAN Netcom communication interface and RS485 communication interface, human-machine interface module comprises LCDs, keyboard and clearing lamp, cpu system is made of 32-bit microprocessor CPU, RAM, ROM, Flash memory etc., high performance 32-bit microprocessor CPU, jumbo ROM, RAM and Flash memory, will make cpu system have extremely strong data processing and registering capacity, can realize various complex failure processing schemes and a large amount of fault data of record.Recordable record ripple report is no less than 10 times in the Flash memory, and recordable event number is no less than 500 times.Operation configuration informations such as protection definite value also deposit in this memory, and these information all can not lost after the device power down.
The switching value input circuit open into amount be divided into inside open into the outside open into, inside open into employing DC24V open into, power supply is provided by power module of the present utility model, open into employing two-stage optical coupling isolation circuit the outside, realizes the direct incoming level of DC220V.
Communication module of the present utility model comprises 10M Ethernet interface and CAN communication interface, Ethernet interface is the main communication interfaces of this device connecting system, the CAN communication interface provides second communication interface when forming double-network communication, in particular cases, also can provide optical fiber interface.
Power module is imported direct current 220V or 110V voltage behind the anti-interference filtration loop; utilize the inversion principle to export three groups of direct voltages that this device needs; be 5V, 24V; 24V and 5V are not altogether; and adopt floating ground mode, continuous with the shell of motor differential protection, wherein; 5V is the working power that is used for CPU and AD conversion loop, 24V be used to drive the relay logic loop and outside open into power supply.
For strengthening the antijamming capability of power supply module, can be at the direct-flow input end installing filter of the utility model power module.
Human-machine interface module MMI major function is the information that shows the integrated cpu system output of protection, and display screen adopts four lines, the LCD of eight Chinese characters of every row, and man-machine interface is clear understandable, and the keyboard operation mode makes human-computer dialogue convenient and simple for operation.Also disposed the clearing lamp indication information on the human-machine interface module MMI, made the operation information of this device more directly perceived.
This kind of protective device is applicable to the mesohigh high capacity motor differential protection of 3-10KV electric pressure.Both can be dispersed in switch cubicle and install on the spot, and also can concentrate group screen to install.And communication interface is provided, can protect with other, automation equipment together, form automated system by communication interface.
Claims (3)
1. motor differential protection; comprise a difference AD sampling circuit that can receive the distolateral and neutral point side current signal of motor machine; cpu system; the switching value input circuit; the relay logic loop; human-machine interface module and power module; it is characterized in that: described motor differential protection also comprises a low-pass filtering circuit units; described low-pass filtering circuit units is connected between the input of motor machine distolateral and neutral point side current signal output end and described difference AD sampling circuit; described low-pass filtering circuit units receives and comes from the current signal that described motor machine is distolateral and the neutral point side current signal output end is exported; behind the filtering high-frequency harmonic, to the current sampling signal of described difference AD sampling circuit output low frequency.
2. according to the motor differential protection described in the claim 1; it is characterized in that: be provided with the photoelectric isolating circuit that comprises luminous tube and photodiode in the described motor differential protection between switching value input circuit and cpu system, the switching signal of described switching value input circuit output outputs to the switching value signal input part of described cpu system by the optocoupler effect of photoelectric isolating circuit.
3. according to the motor differential protection described in the claim 2, it is characterized in that: described low-pass filtering circuit units adopts the Butterworth LPF chip, and described photoelectric isolating circuit adopts linear optical coupling HCNR200 chip.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205125087U CN201781265U (en) | 2010-09-01 | 2010-09-01 | Motor differential protection device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2010205125087U CN201781265U (en) | 2010-09-01 | 2010-09-01 | Motor differential protection device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN201781265U true CN201781265U (en) | 2011-03-30 |
Family
ID=43794468
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2010205125087U Expired - Lifetime CN201781265U (en) | 2010-09-01 | 2010-09-01 | Motor differential protection device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN201781265U (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102364799A (en) * | 2011-11-07 | 2012-02-29 | 四川省电力公司遂宁公司 | Differential protection system for power system substation |
| CN112600163A (en) * | 2020-12-09 | 2021-04-02 | 北京博阳慧源电力科技有限公司 | Motor differential protection method based on optical fiber communication |
-
2010
- 2010-09-01 CN CN2010205125087U patent/CN201781265U/en not_active Expired - Lifetime
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102364799A (en) * | 2011-11-07 | 2012-02-29 | 四川省电力公司遂宁公司 | Differential protection system for power system substation |
| CN112600163A (en) * | 2020-12-09 | 2021-04-02 | 北京博阳慧源电力科技有限公司 | Motor differential protection method based on optical fiber communication |
| CN112600163B (en) * | 2020-12-09 | 2022-05-31 | 北京博阳慧源电力科技有限公司 | Motor differential protection method based on optical fiber communication |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| ASS | Succession or assignment of patent right |
Owner name: DAQING OIL FIELD AUTOMATION INSTRUMENT CO., LTD. Free format text: FORMER OWNER: DAQING OILFIELD NEW CENTURY ELECTRIC POWER AUTOMATION CO., LTD. Effective date: 20111124 |
|
| C41 | Transfer of patent application or patent right or utility model | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20111124 Address after: 163453 Heilongjiang Province, Daqing City Ranghulu District Longnan Co-patentee after: DAQING OILFIELD AUTOMATION INSTRUMENT CO., LTD. Patentee after: Daqing Petroleum Administration Address before: 163453 Heilongjiang Province, Daqing City Ranghulu District Longnan Co-patentee before: Daqing Oilfield Xinshiji Electric Automatization Co., Ltd. Patentee before: Daqing Petroleum Administration |
|
| CX01 | Expiry of patent term | ||
| CX01 | Expiry of patent term |
Granted publication date: 20110330 |