CN205374613U - Unbalanced three phase detection circuitry - Google Patents
Unbalanced three phase detection circuitry Download PDFInfo
- Publication number
- CN205374613U CN205374613U CN201521127634.XU CN201521127634U CN205374613U CN 205374613 U CN205374613 U CN 205374613U CN 201521127634 U CN201521127634 U CN 201521127634U CN 205374613 U CN205374613 U CN 205374613U
- Authority
- CN
- China
- Prior art keywords
- phase
- operational amplifier
- circuit
- resistance
- input end
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Abstract
The utility creatively provides an unbalanced three phase detection circuitry, including three current transformer, three accurate rectifier circuit and a voltage follower, three current transformer's input is used for connecting three phase current's U respectively, and V, W three -phase, every current transformer's output connect an accurate rectifier circuit, the input of connecting voltage follower after 3 outputs incorporation of three accurate rectifier circuit. Compared with the prior art, the utility model discloses the creation has following advantage: through detecting three -phase 12 synthetic steamed bun ripples, with regard to detectable three phase current imbalance degree in the one -period, improved unbalanced three phase's response speed greatly, the emergence of accident is avoided in the big improvement of real -time, and then the protection of in time reporting to the police.
Description
Technical field
The invention belongs to the detection technique field of three-phase current sampling and current unbalance factor, especially relates to a kind of three-phase imbalance testing circuit.
Background technology
Three-phrase burden balance is the basis of safe power supply.Three-phase load is seriously asymmetric, and neutral point potential will offset, and line drop and power loss will be greatly increased.The problems such as low voltage easily occurs in the single-phase user being connected on heavy load phase, and electric light does not work, electrical equipment usefulness reduces, little water pump easily burns.And the single-phase user being connected on light load phase easily occurs that voltage is higher, it is possible to cause electrical apparatus insulation to puncture, shorten electrical equipment service life or damage electrical equipment.For power user, imbalance of three-phase voltage, motor overheating phenomenon can be caused.Three-phase load keeps balance to be energy efficient, drops the basis damaging price reduction.Three-phase load unbalance will produce unbalance voltage, and high voltage offsets, and increase neutral current, thus increasing line loss.It was verified that generally three-phase load unbalance can cause line loss per unit to raise 2%-10%, if three-phase load unbalance degree is more than 10%, then line loss dramatically increases.Only three-phase impedance balance, guarantee low-voltage leakage always protects good operation, it is prevented that person electric shock casualty accident.
Detect three-phase current unbalance at present and mostly be sampling three-phase electric current respectively, by calculating three-phase current data, calculate current differential, and then obtain current unbalance factor, the sampling period so can be caused long, it is impossible to carry out alarm and protection in time.
Summary of the invention
In view of this, the invention is directed to a kind of three-phase imbalance testing circuit, long to solve the sampling period, it is impossible to the problem carrying out alarm and protection in time.
For reaching above-mentioned purpose, the technical scheme of the invention is achieved in that
A kind of three-phase imbalance testing circuit, including three current transformers, three precise rectification circuits and a voltage follower, the input of described three current transformers is respectively intended to connect the U of three phase mains, V, W three-phase, the outfan of each current transformer connects a precise rectification circuit, and 3 outfans of described three precise rectification circuits connect the input of voltage follower after merging.
Further, each precise rectification circuit includes anti-phase scaling circuit 1 and anti-phase scaling circuit 2, and the outfan of described anti-phase scaling circuit 1 connects the reverse input end of anti-phase scaling circuit 2 by the first diode connected and the first resistance；Described anti-phase scaling circuit 1 includes one-level operational amplifier, an indirect diode of described one-level operational amplifier reverse input end and outfan, the anode of the first diode connects one-level operational amplifier reverse input end by a resistance, and described one-level operational amplifier reverse input end is also by the reverse input end of the second resistance connected, the 3rd resistance anti-phase scaling circuit two of connection；
The outfan of each described current transformer two resistance in parallel, the rear reverse input end being connected one-level operational amplifier by the second resistance.
Relative to prior art, the invention has the advantage that
By detecting 12 steamed bread ripples of three-phase synthesis, within a cycle, just can detect three-phase current unbalance degree, improve greatly the response speed of three-phase imbalance, the big raising of real-time, and then carry out alarm and protection in time, it is to avoid the generation of accident.
Accompanying drawing explanation
The accompanying drawing constituting the part of the invention is used for providing being further appreciated by the invention, and the schematic description and description of the invention is used for explaining the invention, is not intended that the improper restriction to the invention.In the accompanying drawings:
Fig. 1 is the circuit diagram of three-phase imbalance testing circuit described in the invention embodiment；
Fig. 2 is the enlarged drawing of a precise rectification circuit in Fig. 1；
Fig. 3 is the enlarged drawing of voltage follower partial circuit described in Fig. 1.
Detailed description of the invention
It should be noted that when not conflicting, the embodiment in the invention and the feature in embodiment can be mutually combined.
Describe the invention below with reference to the accompanying drawings and in conjunction with the embodiments in detail.
A kind of three-phase imbalance testing circuit, as shown in Figures 1 to 3, including three current transformers, the precise rectification circuit of three identical attachment structures and a voltage follower, the input of described three current transformers is respectively intended to connect the U of three phase mains, V, W three-phase, the outfan of each current transformer connects a precise rectification circuit, and 3 outfans of described three precise rectification circuits connect the input of voltage follower after merging.
As shown in Figure 2, it it is one of them precise rectification circuit, including anti-phase scaling circuit 1 and anti-phase scaling circuit 2, the outfan of described anti-phase scaling circuit one connects the reverse input end of anti-phase scaling circuit two by the diode D4 connected and resistance R4；
Described anti-phase scaling circuit 1 includes operational amplifier U1C, an indirect diode D3 of described operational amplifier U1C reverse input end and outfan, the anode of diode D4 connects the reverse input end of operational amplifier U1C by resistance R9, and the reverse input end of described operational amplifier U1C connects the reverse input end of anti-phase scaling circuit 2 also by the resistance R3, the resistance R7 that connect；The outfan of Current Transmit 1 two resistance R1, R2 in parallel, the rear reverse input end being connected one-level operational amplifier by resistance R3.
Two sampling resistors R1, R2 that the output signal flow of described Current Transmit 1 is excessively in parallel, ac voltage signal is generated at resistance R1, R2 two ends, when the positive half-wave of voltage signal, diode D3 ends, diode D4 turns on, operational amplifier U1C forms anti-phase scaling circuit, and the anti-phase scaling circuit 2 then through operation amplifier U2B composition exports the ADC mouth arriving MCU.When the negative half-wave of voltage signal, diode D3 turns on, and diode D4 ends, and operational amplifier U1C is output as 0, exports on the ADC mouth of MCU then through anti-phase scaling circuit 2, obtains precision rectifying waveform.The function of the precise rectification circuit of three-phase electricity is to convert faint alternating voltage to DC voltage, and rectification output retains the shape of input voltage, and only changes the phase place of input voltage.
As it is shown on figure 3, described voltage follower, input stage signal be the composite signal of output signal of above three precise rectification circuit, three-phase resultant voltage is synchronization, for the maximum after three-phase current rectification, and then obtains the steamed bread ripple of 12.
What the operational amplifier constituting described anti-phase scaling circuit 1 and anti-phase scaling circuit 2 and the operational amplifier constituting described voltage follower all selected is model is the operational amplifier of LM224D.
Innovation and creation realize U, V, W three-phase current is first through current transformer, the ADC mouth sending MCU by precise rectification circuit carries out current sample, due to U, V, W three-phase current mutual deviation 120 °, frequency is power frequency 50HZ, cycle T is 20mS, after precision rectifying, the steamed bread ripple direct current signal on three one cycle T/12 of current signal synthesis, roads, this steamed bread ripple signal send the ADC mouth of MCU to carry out sampling and the computing of current unbalance factor through voltage follower, by comparing the difference of the instantaneous value of 12 steamed bread ripples in the cycle, calculate corresponding current unbalance factor, when current unbalance factor is beyond setting value, by the corresponding block of MCU output and alarm signal, equipment is protected.
The foregoing is only the preferred embodiment of the invention; not in order to limit the invention; within all spirit in the invention and principle, any amendment of making, equivalent replacement, improvement etc., should be included within the protection domain of the invention.
Claims (3)
1. a three-phase imbalance testing circuit, it is characterized in that: include three current transformers, three precise rectification circuits and a voltage follower, the input of described three current transformers is respectively intended to connect the U of three phase mains, V, W three-phase, the outfan of each current transformer connects a precise rectification circuit, and 3 outfans of described three precise rectification circuits connect the input of voltage follower after merging.
2. three-phase imbalance testing circuit according to claim 1, it is characterized in that: each precise rectification circuit includes anti-phase scaling circuit 1 and anti-phase scaling circuit 2, the outfan of described anti-phase scaling circuit 1 connects the reverse input end of anti-phase scaling circuit 2 by the first diode connected and the first resistance；
Described anti-phase scaling circuit 1 includes one-level operational amplifier, an indirect diode of described one-level operational amplifier reverse input end and outfan, the anode of the first diode connects one-level operational amplifier reverse input end by a resistance, and described one-level operational amplifier reverse input end is also by the reverse input end of the second resistance connected, the 3rd resistance anti-phase scaling circuit two of connection；
The outfan of each described current transformer two resistance in parallel, the rear reverse input end being connected one-level operational amplifier by the second resistance.
3. three-phase imbalance testing circuit according to claim 2, it is characterised in that: what the operational amplifier constituting described anti-phase scaling circuit 1 and anti-phase scaling circuit 2 and the operational amplifier constituting described voltage follower all selected is model is the operational amplifier of LM224D.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521127634.XU CN205374613U (en) | 2015-12-30 | 2015-12-30 | Unbalanced three phase detection circuitry |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201521127634.XU CN205374613U (en) | 2015-12-30 | 2015-12-30 | Unbalanced three phase detection circuitry |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN205374613U true CN205374613U (en) | 2016-07-06 |
Family
ID=56257946
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201521127634.XU Expired - Fee Related CN205374613U (en) | 2015-12-30 | 2015-12-30 | Unbalanced three phase detection circuitry |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN205374613U (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107247194A (en) * | 2017-07-17 | 2017-10-13 | 国网江西省电力公司电力科学研究院 | A kind of detection method and device of uneven platform area phase modulation effect |
| CN109521284A (en) * | 2018-10-24 | 2019-03-26 | 杜育宽 | Three-phase electricity power failure detection method based on dual factors algorithm |
| CN112070396A (en) * | 2020-09-08 | 2020-12-11 | 国网河北省电力有限公司石家庄供电分公司 | Visualization-based regional power supply risk assessment system and method |
-
2015
- 2015-12-30 CN CN201521127634.XU patent/CN205374613U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107247194A (en) * | 2017-07-17 | 2017-10-13 | 国网江西省电力公司电力科学研究院 | A kind of detection method and device of uneven platform area phase modulation effect |
| CN107247194B (en) * | 2017-07-17 | 2020-04-14 | 国网江西省电力公司电力科学研究院 | Method and device for detecting phase modulation effect of unbalanced transformer area |
| CN109521284A (en) * | 2018-10-24 | 2019-03-26 | 杜育宽 | Three-phase electricity power failure detection method based on dual factors algorithm |
| CN112070396A (en) * | 2020-09-08 | 2020-12-11 | 国网河北省电力有限公司石家庄供电分公司 | Visualization-based regional power supply risk assessment system and method |
| CN112070396B (en) * | 2020-09-08 | 2024-04-09 | 国网河北省电力有限公司石家庄供电分公司 | Regional power supply risk assessment system and method based on visualization |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN205374613U (en) | Unbalanced three phase detection circuitry | |
| CN103701152A (en) | Method and system for obtaining flicker transmission coefficient of grid connection of photovoltaic power stations | |
| CN101246187B (en) | Inverter input current detecting device and method thereof | |
| CN203204062U (en) | Comparator-based voltage signal detection circuit | |
| CN208350969U (en) | A kind of detection circuit and frequency converter | |
| Gopalan et al. | Voltage unbalance: Impact of various definitions on severity assessment for adjustable speed drives | |
| CN102291018B (en) | Single-phase rectifier with APFC (active power factor correction) circuit and alternating-current input voltage amplitude detection method thereof | |
| CN107402324B (en) | Power supply sampling circuit and method based on single current transformer and low-voltage circuit breaker thereof | |
| CN104343713B (en) | The failure detector circuit of ac fan | |
| CN206832896U (en) | A kind of three-phase power input phase-loss detection circuit | |
| CN107478975A (en) | A kind of Insulation Inspection System of energy-accumulating power station | |
| CN206225989U (en) | A kind of phase of three-phase voltage protection circuit | |
| WO2018006517A1 (en) | Method for detecting instantaneous current in intermediate dc link of ac-dc-ac circuit and locomotive | |
| CN206099298U (en) | Power supply monitoring circuit | |
| CN203554321U (en) | IGBT rectifier circuit | |
| CN203929900U (en) | Simple and easy three-phase power supply phase sequence indicator | |
| CN205960977U (en) | Multi -functional DC power supply controller | |
| CN203490357U (en) | Self-detection-type residual current transformer detection circuit | |
| CN206270398U (en) | A kind of voltage x current loop comprehensive tester | |
| CN205193149U (en) | Simple and easy detection circuitry of line voltage | |
| CN210347906U (en) | Sine half-wave and sine alternating current generating device for current transformer detection | |
| CN203942463U (en) | 1000V adjustable DC power supply | |
| CN209525397U (en) | A kind of pile defection device of n phase power supply | |
| CN202939210U (en) | Apparatus used for detecting voltage and phase of low-voltage three-phase transformer | |
| CN216981806U (en) | Debugging table for debugging thyristor in steel rail potential limiting device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20170401 Address after: 300384 in Tianjin Binhai high tech Zone Huayuan Industrial Zone (outer ring) five Haitai Development Road No. 16 Building No. -301 B-9 Patentee after: TIANJIN HINOW SCIENCES&TECHNOLOGY CO., LTD. Address before: 300384 in Tianjin Binhai high tech Zone Huayuan Industrial Zone (outer ring) five Haitai Development Road No. 16 Building No. -201 B-9 Patentee before: TIANJIN CHENGDIAN TECHNOLOGY CO., LTD. |
|
| 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: 20160706 Termination date: 20201230 |