CN203904461U - Cathode protection potentiostat of metal ground grid of substation - Google Patents
Cathode protection potentiostat of metal ground grid of substation Download PDFInfo
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- CN203904461U CN203904461U CN201420283325.0U CN201420283325U CN203904461U CN 203904461 U CN203904461 U CN 203904461U CN 201420283325 U CN201420283325 U CN 201420283325U CN 203904461 U CN203904461 U CN 203904461U
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Abstract
The utility model discloses a cathode protection potentiostat of a metal ground grid of a substation. The cathode protection potentiostat comprises a controllable rectifying circuit, a voltage stabilizing filter circuit, a high-frequency switch, a transformer and a rectifying filter circuit sequentially connected in series and also comprises a first protection circuit, a first drive circuit, a PWM control circuit, a second drive circuit, a second protection circuit and a DSP controller, wherein the DSP controller is connected with the controllable rectifying circuit through the first protection circuit; the DSP controller is connected with the high-frequency switch through the second protection circuit; the DSP controller is connected with the PWM control circuit; the PWM control circuit is connected with the controllable rectifying circuit through the first drive circuit; the PWM control circuit is connected with the high-frequency switch through the second drive circuit. According to the cathode protection potentiostat disclosed by the utility model, by adopting a double-loop series adjustment structure, the adjustment speed is increased, and more importantly, the adjustment margin of a power tube is increased so as to improve the reliability and stability of the potentiostat.
Description
Technical field
The utility model relates to substation's aseptic technic field, particularly relates to a kind of substation metal grounding network cathodic protection potentiostat.
Background technology
Ground net is one of key of guaranteeing the normal operation of substation.Ground net is embedded in underground for a long time, due to the galvanic corrosion of soil, particularly due to the impact of large stray current, makes the corrosion prevention of ground net be different from the corrosion and protection of general underground hardware.Ground net 10 years at most, the several years is just damaged and even ruptures at least.Along with the continuous increase of power system capacity, the earth mat of flowing through to enter ground short circuit electric current also more and more large.In the time that accident occurs; if ground net causes ground connection performance bad because of corrosion; can not bear the electric current that lightning impulse or short circuit accident form; short-circuit current cannot fully spread in soil; cause ground net potential rise, make the metal shell band high-voltage of grounding apparatus and jeopardize personnel safety and puncture secondary protector insulation, even damage equipment; expansion accident, destroys network system stable.Along with the development of electric power network technique, the importance of electricity net safety stable improves constantly, and ground net corrosion has become the essential major issue solving.
Ground net corrosion has many reasons: micro-cell corrosion, the stray current corrosion of soil ununiformity burn into etc.Stray current corrosion is in fact a kind of galvanic corrosion that exists leakage current to produce because of soil, and the position that stray current enters metal from soil is that cathodic area is protected, and is positive column and stray current flows out position from metal, can produce dissolved corrosion.Because the effect of grounding net of transformer substation discharges all kinds of fault currents, induced current, thunder-strike current to the earth exactly, therefore grounding net of transformer substation stray current corrosion is especially serious.
Galvanic protection is protected metal to be applied to negative current make the negative burning reduction equilibrium potential that moves to of its electropotential by cathodic polarization, thus but the guard method of resistance metal reaction.In galvanic protection, judge whether completely protection of metal, conventionally adopt minimum protective potential and Minimal Protective electric current to determine.
Minimum protective potential: metal just can reach guard mode completely in the case of necessary cathodic polarization, makes its combined potential reach the anode equilibrium potential of its corrosion microbattery, and this current potential is known as minimum protective potential.Minimum protective potential and metal species, ambient condition are relevant, and can determine by rule of thumb data or experiment.
Minimum protective current density: when metal is protected completely, needed current density is called minimum protective current density.The kind of its numerical value and metal, metallic surface state, ambient condition etc. are relevant, and generally when the corrodibility of metal in medium is stronger, when cathodic polarization degree is lower, needed protective current density is just larger.
Protection potential is topmost parameter, because electrode process depends on electropotential, its determines the degree of protection of metal, and can utilize it to judge that whether can control galvanic protection complete.And the influence factor of protective current density is more, numerical value change is very large, and when protection potential one timing, current density also can change according to the variation of system, therefore be a minor parameter.In ground net galvanic protection, select protection potential or definite protective current density can reach good anticorrosion ability.
The cloudy potentiostat of impressed current for traditional anticorrosive metal, adopt controlled rectification mode to realize the adjustment of output rating, also the employing IGBT having or MOSFET are as the high frequency switching device in power conversion circuit, when potentiostat output is adjusted, easily there is the problems such as switching tube turn-offs not in time, over-current and-load, cause the damage of instrument device.There is the problems such as efficiency is low, poor stability, reliability is lower, function is simple in these modes.The large stray current present situation of substation's Special complex, needs stable performance, regulates potentiostat sensitive, the high requirement of precision.
Utility model content
For above practical situation, the purpose of this utility model is to provide a kind of substation metal grounding network cathodic protection potentiostat, and this device adopts double loop tandem control, can effectively slow down the erosion rate of grounding net of transformer substation.
To achieve these goals, the utility model adopts following technical scheme:
A kind of substation metal grounding network cathodic protection potentiostat, comprises controlled rectification circuit, filter circuit of pressure-stabilizing, HF switch, transformer and the current rectifying and wave filtering circuit of connecting successively.
The utility model further improves and is: also comprise the first holding circuit, the first driving circuit, pwm control circuit, the second driving circuit, the second holding circuit and dsp controller; Dsp controller connects controlled rectification circuit by the first holding circuit, and dsp controller connects HF switch by the second holding circuit; Dsp controller connects pwm control circuit, and pwm control circuit connects controlled rectification circuit by the first driving circuit, and pwm control circuit connects HF switch by the second driving circuit.
The utility model further improves and is: also comprise voltage sampling circuit and current sampling circuit; The input terminus of voltage sampling circuit connects the output terminal of current rectifying and wave filtering circuit, and the output terminal of voltage sampling circuit connects dsp controller; The input terminus of current sampling circuit connects the output terminal of current rectifying and wave filtering circuit, and the output terminal of current sampling circuit connects dsp controller.
The utility model further improves and is: dsp controller is connected with reference electrode.
The utility model further improves and is: also comprise micro-chip and man-machine interface, man-machine interface connects micro-chip, and micro-chip connects dsp controller.
The utility model further improves and is: micro-chip has RS232/485 interface and multichannel 4-20mA analog interface.
With respect to prior art, the utlity model has following beneficial effect:
A kind of substation of the utility model metal grounding network cathodic protection potentiostat, input power is civil power alternating current 220V, through AC/DC, after DC/DC conversion, output ground net protection required voltage, electric current.The single phase alternating current of this potentiostat input is adjusted the output rating of potentiometer through controlled rectification circuit, belong to single-phase rectifier, adopts controlled rectification mode, when output rating changes, feed back to input terminus, adjust the angle of flow of rectifying tube, thereby adjust the size of output rating.The driving control of the conduction angle of controlled rectifier adopts existing PWM control mode, can change fast the angle of flow of rectifying tube.The setting pulse of rectifying tube conduction angle, adopts the dsp chip that arithmetic speed is higher to produce PWM ripple, acts on the driving circuit of rectifying tube.Through further voltage regulation filtering, become direct current by the electric current after rectification.Direct current, regulating through the PWM of IGBT HF switch pipe, is further adjusted output voltage.
The output of controlled rectification adjusting and HF switch pipe regulating constant potentiometer in the utility model, this is equivalent to have two to adjust loops; The utility model adopts double loop tandem adjustment structure, is the speed of accelerating adjustment on the one hand, and prior reason is the adjustment nargin that increases power tube, to increase the reliability and stability of instrument.
Brief description of the drawings
Fig. 1 is potentiostat structural representation.
Embodiment
Refer to shown in Fig. 1; the utility model substation metal grounding network cathodic protection potentiostat is for the anti-corrosion protection of grounding net of transformer substation; adopt double loop control texture, structure forms as shown in Figure 1: comprise controlled rectification circuit, filter circuit of pressure-stabilizing, HF switch, transformer, current rectifying and wave filtering circuit, the first holding circuit, the first driving circuit, pwm control circuit, the second driving circuit, the second holding circuit, voltage sampling circuit, current sampling circuit, dsp controller.
The input terminus of controlled rectification circuit connects alternating-current AC, output terminal connects the input terminus of filter circuit of pressure-stabilizing, the output terminal of filter circuit of pressure-stabilizing connects one end of HF switch, the input terminus of the other end connection transformer of HF switch, the output terminal of transformer connects the input terminus of current rectifying and wave filtering circuit, the direct current DC after the output terminal output rectification filter of current rectifying and wave filtering circuit.
The input terminus of voltage sampling circuit connects the output terminal of current rectifying and wave filtering circuit, and the output terminal of voltage sampling circuit connects dsp controller.
The input terminus of current sampling circuit connects the output terminal of current rectifying and wave filtering circuit, and the output terminal of current sampling circuit connects dsp controller.Reference electrode connects dsp controller.
Dsp controller connects controlled rectification circuit by the first holding circuit, and dsp controller connects HF switch by the second holding circuit; Dsp controller connects pwm control circuit, and pwm control circuit connects controlled rectification circuit by the first driving circuit, and pwm control circuit connects HF switch by the second driving circuit.
The input of the utility model substation metal grounding network cathodic protection potentiostat is single phase alternating current AC, through controlled rectification circuit rectification; The first driving circuit adopts the conduction angle of the rectifying tube of PWM mode control controlled rectification circuit; The size of the conduction angle of rectifying tube or ON time control output rating, the size of output rating changes according to the ground net current potential size of feedback.The PWM ripple that the utility model produces by dsp controller, amplifies the ON time of the rectifying tube of rear drive controlled rectification circuit through the first driving circuit.Electric current after rectifying tube rectification still has very large fluctuation, needs the processing of further filter circuit of pressure-stabilizing, and the direct current of fluctuation is become to more stable direct current.This step of potentiostat belongs to the process of AC-DC conversion.
The after-current of voltage regulation filtering, still needs further conversion just can reach the requirement of device output, adopts HF switch pipe and transformer composition DC-DC translation circuit, the size of regulation output voltage or electric current.HF switch pipe adopts IGBT pipe, and its driving also adopts PWM control mode, and PWM frequency ratio is higher, produces and uses same dsp controller with the PWM of rectifying tube.
The direct current of filter circuit of pressure-stabilizing output regulates by the PWM of IGBT HF switch, further adjusts output voltage; The PWM ripple that the utility model produces by dsp controller, amplifies rear drive HF switch through the second driving circuit.
The output terminal of transformer connects the input terminus of current rectifying and wave filtering circuit, reaches device output require direct current DC through the further rectifying and wave-filtering of current rectifying and wave filtering circuit.
Dsp controller is connected with reference electrode, measures real protection current potential; According to the current potential detecting, produce PWM ripple control controlled rectification circuit and HF switch, control output voltage or the electric current of potentiostat; The change of output voltage or electric current causes the variation of protection potential, the protection potential of ground net is controlled at-below 850mV, the anti-corrosion protection of the earth mat that achieves a butt joint.Controlled rectification regulates the output with HF switch pipe regulating constant potentiometer, and this is equivalent to have two to adjust loop; The utility model adopts double loop tandem adjustment structure, is the speed of accelerating adjustment on the one hand, and prior reason is the adjustment nargin that increases power tube, to increase the reliability and stability of instrument.
Preferably, the utility model can also comprise singlechip controller and man-machine interface, and man-machine interface connects micro-chip, and micro-chip connects dsp controller; Micro-chip is for man-machine interface input, the output of system, the contact of communication interface etc., the control of the two whole system of having worked in coordination and detection.Man-machine interface adopts technical grade touch-screen, the setting of protection potential, and the setting of controlling parameter can be arranged and be checked by touch-screen.Micro-chip has RS232/485 interface and multichannel 4-20mA analog interface, can make in the TT&C system such as the on-the-spot PLC of the direct access industrial of instrument or DCS.TT&C system connects by RS232/485 interface, according to the communications protocol designing, can teletransmission control, detect output voltage, the electric current of potentiostat, the current potential height of ground net, and the operating mode of system is set.Potentiostat has multichannel 4-20mA analog interface, is respectively used to the detection of voltage, electric current, the setting of current potential, voltage, electric current.
Claims (6)
1. substation's metal grounding network cathodic protection potentiostat, is characterized in that, comprises controlled rectification circuit, filter circuit of pressure-stabilizing, HF switch, transformer and the current rectifying and wave filtering circuit of series connection successively.
2. substation according to claim 1 metal grounding network cathodic protection potentiostat, is characterized in that, also comprises the first holding circuit, the first driving circuit, pwm control circuit, the second driving circuit, the second holding circuit and dsp controller; Dsp controller connects controlled rectification circuit by the first holding circuit, and dsp controller connects HF switch by the second holding circuit; Dsp controller connects pwm control circuit, and pwm control circuit connects controlled rectification circuit by the first driving circuit, and pwm control circuit connects HF switch by the second driving circuit.
3. substation according to claim 1 metal grounding network cathodic protection potentiostat, is characterized in that, also comprises voltage sampling circuit and current sampling circuit; The input terminus of voltage sampling circuit connects the output terminal of current rectifying and wave filtering circuit, and the output terminal of voltage sampling circuit connects dsp controller; The input terminus of current sampling circuit connects the output terminal of current rectifying and wave filtering circuit, and the output terminal of current sampling circuit connects dsp controller.
4. substation according to claim 1 metal grounding network cathodic protection potentiostat, is characterized in that, dsp controller is connected with reference electrode.
5. substation according to claim 1 metal grounding network cathodic protection potentiostat, is characterized in that, also comprises micro-chip and man-machine interface, and man-machine interface connects micro-chip, and micro-chip connects dsp controller.
6. substation according to claim 5 metal grounding network cathodic protection potentiostat, is characterized in that, micro-chip has RS232/485 interface and multichannel 4-20mA analog interface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420283325.0U CN203904461U (en) | 2014-05-29 | 2014-05-29 | Cathode protection potentiostat of metal ground grid of substation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420283325.0U CN203904461U (en) | 2014-05-29 | 2014-05-29 | Cathode protection potentiostat of metal ground grid of substation |
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| Publication Number | Publication Date |
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| CN203904461U true CN203904461U (en) | 2014-10-29 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201420283325.0U Expired - Fee Related CN203904461U (en) | 2014-05-29 | 2014-05-29 | Cathode protection potentiostat of metal ground grid of substation |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104988512A (en) * | 2015-02-28 | 2015-10-21 | 中国石油大学(北京) | Cathode protection device and protection method thereof |
| CN105112921A (en) * | 2015-08-17 | 2015-12-02 | 国家电网公司 | Intelligent anti-corrosion protecting and monitoring system of grounding network |
| CN116262972A (en) * | 2021-12-13 | 2023-06-16 | 中国石油天然气股份有限公司 | Casing cathode protection equipment based on impressed current |
-
2014
- 2014-05-29 CN CN201420283325.0U patent/CN203904461U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104988512A (en) * | 2015-02-28 | 2015-10-21 | 中国石油大学(北京) | Cathode protection device and protection method thereof |
| CN104988512B (en) * | 2015-02-28 | 2017-10-10 | 中国石油大学(北京) | A kind of cathode protection device and its guard method |
| CN105112921A (en) * | 2015-08-17 | 2015-12-02 | 国家电网公司 | Intelligent anti-corrosion protecting and monitoring system of grounding network |
| CN116262972A (en) * | 2021-12-13 | 2023-06-16 | 中国石油天然气股份有限公司 | Casing cathode protection equipment based on impressed current |
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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: 20141029 |