CN203216631U - Power transformer Pt100 signal conversion apparatus with lightning-stroke protection - Google Patents
Power transformer Pt100 signal conversion apparatus with lightning-stroke protection Download PDFInfo
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- CN203216631U CN203216631U CN 201320210327 CN201320210327U CN203216631U CN 203216631 U CN203216631 U CN 203216631U CN 201320210327 CN201320210327 CN 201320210327 CN 201320210327 U CN201320210327 U CN 201320210327U CN 203216631 U CN203216631 U CN 203216631U
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Abstract
The utility model, which belongs to the field of temperature detection of a power transformer, especially discloses a power transformer Pt100 signal conversion apparatus with lightning-stroke protection. The signal conversion apparatus comprising a circuit connected with a Pt100 temperature sensor in a power transformer is characterized in that a lightning protection circuit and a Pt100 temperature collection circuit are installed at the circuit; the Pt100 temperature collection circuit is communicated with a non-linear compensation circuit; the non-linear compensation circuit is communicated with a 4 to 20-mA current generation circuit; and an AC-DC power supply circuit is respectively communicated with the non-linear compensation circuit and the 4 to 20-mA current generation circuit. According to the utility model, the anti-interference capability is good. Multiple lightning protection measures are taken inside the apparatus to suppress inductive lightning waves from a signal line and a power line; and the apparatus has a lightning surge self-recovery function.
Description
(1) technical field
The utility model belongs to power transformer temperature detection field, particularly a kind of anti-thunderbolt power transformer Pt100 chromacoder.
(2) background technology
Power transformer is equipped with temperature-detecting device can prevent effectively that transformer Yin Wendu is too high and accidents caused, can also promote the scientific management to the transformer use simultaneously, thereby effectively prolongs the serviceable life of transformer.At present, the temperature detection sensor of power transformer mostly adopts the Pt100 platinum resistance temperature sensor.The resistance value of metal platinum varies with temperature and changes, and has good reappearance and stability, the scales that utilizes this physical characteristics of platinum to make is platinum resistance temperature sensor, normally used platinum resistance temperature sensor zero degree resistance is 100 Ω, resistance change rate be about 0.3851 Ω/℃.Platinum resistance temperature sensor precision height, good stability, temperature limit is wide, is the most frequently used a kind of Temperature Detector of middle low-temperature space (200 ~ 650 ℃), not only is widely used in industrial thermometric, and is made into various standard thermometers for metering and calibration use.
The Pt100 sensor is exactly to utilize the resistance of platinum resistance to vary with temperature and change and the characteristic that is certain funtcional relationship is carried out the temperature sensor of thermometric, Pt100 is a kind of temperature-measuring element of widespread use, has advantages such as precision height, good stability in-200 ℃ ~ 600 ℃ scope.
The temperature of Pt100/resistance corresponding relation is: (1)-200 ℃＜
tIn the time of＜0 ℃,
R Pt100
=100[1+At+B
t 2+ C
t 3(
t-100)]
(2) 0 ℃≤
tIn the time of≤850 ℃,
R Pt100
=100(1+A
t+ B
t 2)
In the formula, A=3.90802 * 10
-3B=-5.80 * 10
-7C=4.2735 * 10
-12
From top formula as can be seen, the resistance of Pt100 temperature sensor raises with temperature and increases, present the relation of approximately linear, but be not absolute linear relationship, and temperature more high linearity is more poor.
Because the Pt100 sensor is temperature variant to be resistance value, generally need to convert thereof into voltage or current signal and use with convenient.The advantage that changes into the voltage signal use is that signal is handled well, and shortcoming is that long Distance Transmission signal has decay, and is subject to relatively disturb; Converting the advantage that electric current use to use to is to grow Distance Transmission, and in the not decay of input terminal voltage of back-end processing equipment, the antijamming capability voltage signal that compares is strong; Therefore a lot of industry spot Pt100 signals transmit and all adopt 4 ~ 20mA electric current, represent zero-signal with 4mA, the full scale of representing signal with 20mA, again current signal is converted to voltage signal to receiving end, to reduce the transfer wire impedance to the interference to signal of the influence of signal and delivering path, realized that long distance reliably transmits.
The temperature monitoring of power transformer mostly adopts Pt100 as temperature sensor, adopts 4 ~ 20mA electric current as the transmission signal, and temperature-measuring range is 0 ℃ ~ 160 ℃ or 0 ℃ ~ 200 ℃.The signal processing model that present power transformer Pt100 chromacoder mostly adopts is, the Pt100 thermal resistance is converted to voltage signal through the Pt100 signal acquisition circuit, by amplify, conditioning is by A/D(mould/number) change-over circuit is converted to digital signal, again by single-chip microcomputer or dsp chip by software programming, adopt mode such as table look-up to realize nonlinear compensation to the Pt100 sensor, digital signal after the compensation is through the D/A(D/A) change-over circuit is converted to voltage signal, again through the V/I(voltage/current) change-over circuit is converted to 4～20mA current signal.
(3) summary of the invention
The utility model provides the anti-thunderbolt power transformer Pt100 chromacoder that a kind of antijamming capability is strong, reliability is high in order to remedy the deficiencies in the prior art.
The utility model is achieved by the following technical solution:
A kind of anti-thunderbolt power transformer Pt100 chromacoder; comprise the circuit that connects Pt100 temperature sensor in the power transformer; it is characterized in that: lightning protected circuit and Pt100 temperature collection circuit are installed on the described circuit; Pt100 temperature collection circuit and non-linear compensation circuit are interconnected; non-linear compensation circuit is communicated with 4 ~ 20mA current generating circuit, and the AC-DC power circuit is communicated with non-linear compensation circuit and 4 ~ 20mA current generating circuit respectively.
The present invention utilizes the non-linear of analog calibration circuit compensation Pt100 temperature sensor, and all function switching signal realizes that by mimic channel the stable output signal after the conversion is good fully, and antijamming capability is strong, the reliability height.Direct warm swap when breaking down is changed under no cut-off condition, can effectively reduce the power off time outside the plan of power transformer, shortens the breakdown maintenance time.
This uses novel hardware using modular design; multinomial lightning protected measure has been taked in device inside; can suppress from the induction lightening ripple on signal wire and the power lead, possess the lightning impulse self-recovering function, can effectively improve the average non-failure operation time of power transformer.
4 ~ 20mA current output signal good stability after this conversion equipment is changed in addition, antijamming capability is strong, and the reliability height has characteristics such as volume is little, in light weight, reliable.Hardware plug formula interface, the mounting, commissioning and maintenance cost is low.Adopt the power transformer temperature monitoring system of this conversion equipment need not external lightning protection equipment, can recover automatically behind the lightning impulse.
More excellent scheme of the present utility model is:
Described lightning protected circuit comprises that the sensor that connects the Pt100 temperature collection circuit inserts the lightning protected circuit of passage, is communicated with the lightning protected circuit of 4 ~ 20mA output channel of 4 ~ 20mA current generating circuit and is connected lightning protected circuit three parts of 220V interchange input channel of AC-DC power circuit.
The utility model utilizes the non-linear of analog calibration circuit compensation Pt100 temperature sensor, thereby do not need use to be subject to electromagnetic interference (EMI), the single-chip microcomputer that needs software-driven, digital signal processor little process chip such as (DSP) and the gate circuit that is subject to the spike interference, logical devices such as trigger carry out the nonlinear compensation of Pt100 temperature sensor, all function switching signal is realized by mimic channel fully, thereby overcome originally because adopting single-chip microcomputer, digital signal processor and mould/number, DLC (digital logic circuit) such as D/A switch and the problem that is subject to electromagnetic interference (EMI) that causes, reliability and the antijamming capability of system have been improved greatly, and when breaking down direct warm swap, under no cut-off condition, change, can effectively reduce the power off time outside the plan of power transformer, shorten the breakdown maintenance time.
In addition; original system or other do not take the Pt100 chromacoder of lightning protected measure because there not being lightning protected measure; components and parts (especially single-chip microcomputer and DLC (digital logic circuit)) damage easily when running into thunderbolt or other strong electromagnetic; thereby cause 4 ~ 20mA current signal to lose; must can safeguard just behind system blackout when this thing happens that inside the plan power failure requirement is very disadvantageous to transformer for this.Multinomial lightning protected measure has been taked in the utility model device inside; can suppress from the induction lightening ripple on signal wire and the power lead; possesses the lightning impulse self-recovering function; thereby overcome the anti-thunderbolt poor performance of original system and break down after the shortcoming that must have a power failure change, thereby average non-failure operation time of effectively having improved power transformer.
The utility model antijamming capability is strong, and multinomial lightning protected measure has been taked in device inside, can suppress to possess the lightning impulse self-recovering function from the induction lightening ripple on signal wire and the power lead; 4 ~ 20mA current output signal good stability after the conversion, the reliability height has characteristics such as volume is little, in light weight, reliable.
(4) description of drawings
Below in conjunction with accompanying drawing the utility model is further described.
Fig. 1 is structural representation of the present utility model.
Among the figure; 1 power transformer; 2 Pt100 temperature sensors; 3 sensors insert the lightning protected circuit of passage, 4 Pt100 temperature collection circuits, 5 non-linear compensation circuits; 64 ~ 20mA current generating circuit; 7 AC-DC power circuits, the lightning protected circuit of 84 ~ 20mA output channel, 9 220V exchange the lightning protected circuit of input channel.
(5) embodiment
Accompanying drawing is a kind of specific embodiment of the present utility model.This embodiment comprises the circuit that connects Pt100 temperature sensor 2 in the power transformer 1, lightning protected circuit and Pt100 temperature collection circuit 4 are installed on the described circuit, Pt100 temperature collection circuit 4 and non-linear compensation circuit 5 are interconnected, non-linear compensation circuit 5 is communicated with 4 ~ 20mA current generating circuit 6, and AC-DC power circuit 7 is communicated with non-linear compensation circuit 5 and 4 ~ 20mA current generating circuit 6 respectively; Described lightning protected circuit comprises that the sensor that connects Pt100 temperature collection circuit 4 inserts the lightning protected circuit 3 of passage, is communicated with the lightning protected circuit 8 of 4 ~ 20mA output channel of 4 ~ 20mA current generating circuit 6 and is connected lightning protected circuit 9 three parts of 220V interchange input channel of AC-DC power circuit 7.
Pt100 temperature collection circuit 4 is responsible for the Pt100 signals collecting, is converted into voltage signal, amplifies, nurses one's health the back as the input of non-linear compensation circuit.Pt100 temperature sensor 2 adopts three-wire system, three sectional area of wire of drawing from sensor and identical length with, the circuit of measuring the Pt100 platinum resistance is unbalanced bridge, the Pt100 platinum resistance is as an arm resistance of electric bridge, with power end of receiving electric bridge of lead, on all the other two brachium pontis of receiving the brachium pontis at platinum resistance place respectively and being adjacent, when bridge balancing, the variation of conductor resistance to measurement result without any influence, so just eliminate the measuring error that wire line resistance brings, reduced the additive error that conductor resistance brings greatly.By the Pt100 platinum resistance is connected in the bridge diagram, make the resistance variations signal be converted to voltage change signal, adjust the size of bridge circuit output voltage by the size of selecting electric bridge brachium pontis resistance, the voltage signal amplifying circuit of forming through operational amplifier LM324 amplifies and nurses one's health then, sends into non-linear compensation circuit 5 and compensates.
The voltage signal that Pt100 temperature sensor 2 signals convert to after Pt100 temperature collection circuit 4 is gathered, amplified is:
V O=
k×{[(
?R Pt100
/(
R B1 +
R Pt100
)]?×
V CC -[(
100/(
R B1 +
100)]?×
V CC }
Wherein
kBe the enlargement factor of amplifier in the Pt100 temperature collection circuit 4,
R B1 For removing in the unbalanced bridge
R Pt100
Another outer arm resistance,
V CC Supply voltage for electric bridge.When
R B1 Much larger than
R Pt100
The time, but the following formula abbreviation is:
V O=
k* (
C 1*
R Pt100
-
C 2) *
V CC (wherein
C 1,
C 2Be by
R B1 The constant that determines)
The voltage signal that is Pt100 temperature sensor 2 after gathering, amplifying conversion and the resistance of sensor itself
R Pt100
And the supply voltage of electric bridge
V CC Be directly proportional, therefore by suitably regulating
V CC Big I effectively eliminate the non-linear of Pt100 temperature sensor 2.Specific implementation can be finished by the adjustable integrated regulator LM317 of three ends, will
V OAs the voltage adjustment end of negative-feedback signal control LM317, make LM317 voltage output with
V OIncrease and suitably reduce, thereby just compensate by Pt100 temperature sensor 2 cause non-linear.
4 ~ 0mA current generating circuit 6 is used for realizing the V/I(voltage/current) conversion, Pt100 temperature collection circuit 4 is gathered, amplified and be converted to 4 ~ 20mA current signal through non-linear compensation circuit 5 compensated voltage signals.The specific implementation that 4 ~ 20mA electric current produces is finished by V/I conversion chip AD694.
Lightning protected circuit comprises that sensor inserts that passage is lightning protected 3,220V exchanges input channel lightning protected 9 and lightning protected 8 three partial circuits of 4 ~ 20mA output channel.Sensor inserts the lightning protected circuit 3 of passage for the treatment of the electromagnetic interference signals such as lightning surge from Pt100 temperature sensor 2 and connecting line introducing thereof; 2 three connecting lines of Pt100 temperature sensor respectively connect a voltage dependent resistor (VDR) and a two-way transient absorption diode over the ground; three connecting lines between any two respectively 30V connect voltage dependent resistor (VDR) and two-way transient absorption diode; form parallel anti-lightning surge holding circuit, effectively prevent from disturbing damage Pt100 temperature sensor 2 and chromacoder from the thunder and lightning that Pt100 temperature sensor 2 connecting lines are introduced.220V exchanges the lightning protected circuit 9 of input channel for the treatment of the electromagnetic interference signals of introducing from AC power such as lightning surge; 220V exchanges between input live wire and the zero line and connects 470V voltage dependent resistor (VDR) and 0.1uF electric capacity; live wire and zero line connect the high-voltage capacitance of 0.0022uF over the ground respectively; form the anti-lightning surge circuit of parallel single-phase formula; realization common mode, difference are touched full guard, thereby effectively prevent from exchanging thunder and lightning interference or other electromagnetic interference (EMI) damage Pt100 chromacoder that input channel is introduced from 220V.The lightning protected circuit 8 of 4 ~ 20mA output channel is for the treatment of the electromagnetic interference signals of introducing from 4 ~ 20mA electric current loop such as lightning surge; meet 30V between 4 ~ 20mA electric current loop and connect voltage dependent resistor (VDR) and two-way transient absorption diode; connect simultaneously the high-voltage capacitance of 0.0022uF over the ground; form the parallel anti-lightning surge holding circuit of current loop, prevent from disturbing damage Pt100 chromacoder and relevant back-end processing circuit from the thunder and lightning that 4 ~ 20mA electric current loop is introduced.
AC-DC power circuit 7 is used for from 220V AC power generation+24V DC voltage; produce 6 and lightning protectedly wait the circuit use for Pt100 temperature acquisition 4, nonlinear compensation 5,4 ~ 20mA electric current; AC-DC power circuit 7 has adopted interlock circuits such as isolation, filtering, decoupling, guaranteed whole Pt100 chromacoder required+reliability and the antijamming capability of 24V DC voltage.
The utility model utilizes the non-linear of analog calibration circuit compensation Pt100 temperature sensor, in 0 ℃ ~ 200 ℃ whole range ability, nonlinearity erron is less than 0.1%, the temperature detection error is less than 1%, and the signal conversion performance reaches or is better than adopting single-chip microcomputer (or dsp chip) to carry out the monolithic type Pt100 chromacoder of Pt100 sensor nonlinear compensation.Owing to the whole function switching signals of anti-thunderbolt Pt100 chromacoder are realized by mimic channel fully, and install inside and taked multinomial lightning protected measure, thereby have very strong anti-electromagnetic interference capability and lightning impulse automatic recovery ability.Adopt this device can improve power transformer temperature monitoring system reliability of operation greatly, effectively reduce the power off time outside the plan of power transformer, improve the average non-failure operation time of power transformer.
Claims (2)
1. anti-thunderbolt power transformer Pt100 chromacoder; comprise the circuit that connects power transformer (1) interior Pt100 temperature sensor (2); it is characterized in that: lightning protected circuit and Pt100 temperature collection circuit (4) are installed on the described circuit; Pt100 temperature collection circuit (4) and non-linear compensation circuit (5) are interconnected; non-linear compensation circuit (5) is communicated with 4 ~ 20mA current generating circuit (6), and AC-DC power circuit (7) is communicated with non-linear compensation circuit (5) and 4 ~ 20mA current generating circuit (6) respectively.
2. anti-thunderbolt power transformer Pt100 chromacoder according to claim 1 is characterized in that: described lightning protected circuit comprises that the sensor that connects Pt100 temperature collection circuit (4) inserts the lightning protected circuit of passage (3), is communicated with the lightning protected circuit of 4 ~ 20mA output channel (8) of 4 ~ 20mA current generating circuit (6) and is connected lightning protected circuit (9) three parts of 220V interchange input channel of AC-DC power circuit (7).
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320210327 CN203216631U (en) | 2013-04-24 | 2013-04-24 | Power transformer Pt100 signal conversion apparatus with lightning-stroke protection |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 201320210327 CN203216631U (en) | 2013-04-24 | 2013-04-24 | Power transformer Pt100 signal conversion apparatus with lightning-stroke protection |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN203216631U true CN203216631U (en) | 2013-09-25 |
Family
ID=49206158
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 201320210327 Expired - Fee Related CN203216631U (en) | 2013-04-24 | 2013-04-24 | Power transformer Pt100 signal conversion apparatus with lightning-stroke protection |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN203216631U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103234653A (en) * | 2013-04-24 | 2013-08-07 | 山东达驰电气有限公司 | Pt100 signal conversion device for thunder-strike resisting electric transformer |
-
2013
- 2013-04-24 CN CN 201320210327 patent/CN203216631U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103234653A (en) * | 2013-04-24 | 2013-08-07 | 山东达驰电气有限公司 | Pt100 signal conversion device for thunder-strike resisting electric transformer |
| CN103234653B (en) * | 2013-04-24 | 2015-07-15 | 山东达驰电气有限公司 | Pt100 signal conversion device for thunder-strike resisting electric transformer |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20130925 Termination date: 20160424 |