CN103760410B - A kind of three-phase AC detection circuit and measuring method - Google Patents
A kind of three-phase AC detection circuit and measuring method Download PDFInfo
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Abstract
The invention discloses a kind of three-phase AC detection circuit, comprise first, two, three voltage reduction modules, first, two, three subtraction circuit modules and first, two, three filtration modules, described first voltage reduction module input end is connected with the first three-phase alternating current, output terminal is connected with described first subtraction circuit module positive input and described 3rd subtraction circuit module reverse input end respectively, described second voltage reduction module input end is connected with the second three-phase alternating current, output terminal is connected with described second subtraction circuit module positive input and described first subtraction circuit module reverse input end respectively, described 3rd voltage reduction module input end is connected with the 3rd three-phase alternating current.The defect that the present invention exists for overcoming traditional three-phase alternating current metering circuit, and this invention does not need mandatory requirement to access zero line, whether zero line accesses the measurement that can not affect actual three-phase alternating current.
Description
Technical field
The present invention relates to a kind of three-phase AC detection circuit and measuring method.
Background technology
In the industrial production and in daily life, three-phase alternating current is used to be widely used for equipment carries out powering.But in use, usually need the physical quantitys such as the real-time phase sequence to three-phase electricity, quality of balance, voltage to monitor.And traditional three-phase electricity metering circuit has certain limitation, mainly comprise: " zero line " of triple-phase line must be accessed; Necessarily require " direct current biasing (+Vref) " circuit; " line voltage " must be converted by " phase voltage+phase differential ".
Summary of the invention
The object of the present invention is to provide a kind of three-phase AC detection circuit and measuring method, for overcoming the defect that traditional three-phase alternating current metering circuit exists, and this invention does not need mandatory requirement to access zero line, whether zero line accesses the measurement that can not affect actual three-phase alternating current.
For achieving the above object, present invention employs following technical scheme:
A kind of three-phase AC detection circuit, it comprises first, two, three voltage reduction modules, first, two, three subtraction circuit modules and first, two, three filtration modules, described first voltage reduction module input end is connected with the first three-phase alternating current A, output terminal is connected with described first subtraction circuit module positive input and described 3rd subtraction circuit module reverse input end respectively, described second voltage reduction module input end is connected with the second three-phase alternating current B, output terminal is connected with described second subtraction circuit module positive input and described first subtraction circuit module reverse input end respectively, described 3rd voltage reduction module input end is connected with the 3rd three-phase alternating current C, output terminal is connected with described 3rd subtraction circuit module positive input and described second subtraction circuit module reverse input end respectively, described first subtraction circuit module output terminal is connected with described first filtration module input end, described second subtraction circuit module output terminal is connected with described second filtration module input end, described 3rd subtraction circuit module output terminal is connected with described 3rd filtration module input end, described first voltage reduction module earth terminal, described second voltage reduction module earth terminal and described 3rd voltage reduction module ground connection termination signal ground, described first filtration module earth terminal, described second filtration module earth terminal and the equal ground connection of described 3rd filtration module earth terminal, described first filtration module output terminal, described second filtration module output terminal and described 3rd filtration module output terminal are as signal output part.
Preferably, described 3rd voltage reduction module earth terminal is connected with three-phase alternating current zero line.
Preferably, described first voltage reduction module, comprise the first resistance, the second resistance and the first electric capacity, described first resistance one end is connected with the first three-phase alternating current, the other end is connected with described second resistance one end and described first electric capacity one end respectively, the described second resistance other end and the equal ground connection of the described first electric capacity other end
Described second voltage reduction module, comprise the 8th resistance, the 9th resistance and the 4th electric capacity, described 8th resistance one end is connected with the second three-phase alternating current, the other end is connected with described 9th resistance one end and described 4th electric capacity one end respectively, the described 9th resistance other end and the equal ground connection of the described 4th electric capacity other end
Described 3rd voltage reduction module, comprise the 15 resistance, the 16 resistance and the 7th electric capacity, described 15 resistance one end is connected with the 3rd three-phase alternating current, the other end is connected with described 16 resistance one end and described 7th electric capacity one end respectively, the described 16 resistance other end is connected with three-phase alternating current zero line, the described 16 resistance other end and the equal ground connection of the described 7th electric capacity other end
Described first subtraction circuit module, comprise the 3rd, four, five and six resistance and the first operational amplifier, described 3rd resistance one end is connected with described first electric capacity one end, the described 3rd resistance other end is connected with described 5th resistance one end and described first operational amplifier positive input respectively, described 5th resistance other end ground connection, described 4th resistance one end is connected with described 4th electric capacity one end, the described 4th resistance other end is connected with described 6th resistance one end and described first operational amplifier reverse input end respectively, the described 6th resistance other end is connected with described first operational amplifier output terminal,
Described second subtraction circuit module, comprise the tenth, 11, 12 and 13 resistance and the second operational amplifier, described tenth resistance one end is connected with described 4th electric capacity one end, the described tenth resistance other end is connected with described 12 resistance one end and described second operational amplifier positive input respectively, described 12 resistance other end ground connection, described 11 resistance one end is connected with described 7th electric capacity one end, the described 11 resistance other end is connected with described 13 resistance one end and described second operational amplifier reverse input end respectively, the described 13 resistance other end is connected with described second operational amplifier output terminal,
Described 3rd subtraction circuit module, comprise the 17, 18, 19 and 20 resistance and the 3rd operational amplifier, described 17 resistance one end is connected with described 7th electric capacity one end, the described 17 resistance other end is connected with described 19 resistance one end and described 3rd operational amplifier positive input respectively, described 19 resistance other end ground connection, described 18 resistance one end is connected with described first electric capacity one end, the described 18 resistance other end is connected with described 20 resistance one end and described 3rd operational amplifier reverse input end respectively, the described 20 resistance other end is connected with described 3rd operational amplifier output terminal,
Described first filtration module, comprises the 7th resistance and the 3rd electric capacity, and described 7th resistance one end is connected with described first operational amplifier output terminal, described 3rd electric capacity one end ground connection, the described 7th resistance other end and the described 3rd electric capacity other end connect into node, and this node is as signal output part
Described second filtration module, comprise the 14 resistance and the 6th electric capacity, described 14 resistance one end is connected with described second operational amplifier output terminal, described 6th electric capacity one end ground connection, the described 14 resistance other end and the described 6th electric capacity other end connect into node, this node is as signal output part
Described 3rd filtration module, comprise the 21 resistance and the 9th electric capacity, described 21 resistance one end is connected with described 3rd operational amplifier output terminal, described 9th electric capacity one end ground connection, the described 21 resistance other end and the described 9th electric capacity other end connect into node, and this node is as signal output part.
A measuring method for three-phase AC detection circuit as above, it comprises the steps:
1) be the sinusoidal weak signal of " line voltage " by " phase voltage " of three-phase alternating current by three-phase AC detection circuit conditioning;
2) in the time of setting, microprocessor carries out continuous print AD sampling to " line voltage " the sinusoidal weak signal after conditioning;
3) to step 2) in sampling AD value carry out algorithm process, three-phase electricity is monitored in real time.
Preferably, step 2) described in setting time be greater than half signal period.
Three phase lines and zero line carry out step-down process by voltage reduction module, the sampled signal of phases line voltage is accessed subtraction circuit module and is produced the sinusoidal weak signal of line voltage by filtration module; The signal optional connection load zero-bit of zero line.The weak signal access microprocessor of the three-phase line voltage after conditioning, by microprocessor carrying out AD sampling and processing the weak signal after conditioning, can realize monitoring in real time three-phase alternating current.
Compared with prior art, beneficial effect of the present invention is:
1, do not need to force access zero line, it is wide that on-the-spot applicability compares traditional metering circuit;
2, directly measure " line voltage " not need to be converted by " phase voltage+phase differential ",
Reduce intermediate conversion links, comparatively traditional measurement circuit is high for line voltage measurement precision;
3, judge three-phase electricity zero passage order by doing measurements and calculations to line voltage, zero line is connect
The uncertainty whether entered is got rid of, thus ensure that the standard of the measurement measurement result of three-phase electricity
True property.
Accompanying drawing explanation
Fig. 1 is the circuit block diagram of three-phase AC detection circuit of the present invention;
Fig. 2 is the circuit diagram of three-phase AC detection circuit in a preferred embodiment of the present invention;
Fig. 3 is the sinusoidal weak signal functional arrangement of line voltage when phase sequence is correct in Fig. 2 embodiment;
The sinusoidal weak signal functional arrangement of line voltage when Fig. 4 is phase sequence mistake in Fig. 2 embodiment;
The sinusoidal weak signal functional arrangement of line voltage when Fig. 5 is phase shortage in Fig. 2 embodiment.
Embodiment
Consult Fig. 1-5, this three-phase AC detection circuit comprises the first resistance R1, second resistance R2, 3rd resistance R3, 4th resistance R4, 5th resistance R5, 6th resistance R6, 7th resistance R7, 8th resistance R8, 9th resistance R9, tenth resistance R10, 11 resistance R11, 12 resistance R12, 13 resistance R13, 14 resistance R14, 15 resistance R15, 16 resistance R16, 17 resistance R17, 18 resistance R18, 19 resistance R19, 20 resistance R20, 21 resistance R21, first electric capacity C1, 3rd electric capacity C3, 4th electric capacity C4, 6th electric capacity C6, 7th electric capacity C7, 9th electric capacity C9, first operational amplifier U1, second operational amplifier U2 and the 3rd operational amplifier U3,
First resistance R1 one end and the first three-phase alternating current (also can called after " three-phase alternating current A ") phase L_A is connected, the other end is connected with second resistance R2 one end and first electric capacity C1 one end respectively, the second resistance R2 other end and the first electric capacity C1 other end all meet signal ground Signal_GND
8th resistance R8 one end and the second three-phase alternating current (also can called after " three-phase alternating current B ") phase L_B is connected, the other end is connected with the 9th resistance R9 one end and the 4th electric capacity C4 one end respectively, the 9th resistance R9 other end and the 4th electric capacity C4 other end all meet signal ground Signal_GND
15 resistance R15 one end and the 3rd three-phase alternating current (also can called after " three-phase alternating current C ") phase L_C is connected, the other end is connected with the 16 resistance R16 one end and the 7th electric capacity C7 one end respectively, the 16 resistance R16 other end is connected with three-phase alternating current zero line L_N, the 16 resistance R16 other end and the 7th electric capacity C7 other end all meet signal ground Signal_GND
3rd resistance R3 one end is connected with first electric capacity C1 one end, the 3rd resistance R3 other end is connected with the 5th resistance R5 one end and the first operational amplifier U1 positive input respectively, 5th resistance R5 other end ground connection GND, 4th resistance R4 one end is connected with the 4th electric capacity C4 one end, the 4th resistance R4 other end is connected with the 6th resistance R6 one end and the first operational amplifier U1 reverse input end respectively, the 6th resistance R6 other end is connected with the first operational amplifier U1 output terminal
Tenth resistance R10 one end is connected with the 4th electric capacity C4 one end, the tenth resistance R10 other end is connected with the 12 resistance R12 one end and the second operational amplifier U2 positive input respectively, 12 resistance R12 other end ground connection GND, 11 resistance R11 one end is connected with the 7th electric capacity C7 one end, the 11 resistance R11 other end is connected with the 13 resistance R13 one end and the second operational amplifier U2 reverse input end respectively, the 13 resistance R13 other end is connected with the second operational amplifier U2 output terminal
17 resistance R17 one end is connected with the 7th electric capacity C7 one end, the 17 resistance R17 other end is connected with the 19 resistance R19 one end and the 3rd operational amplifier U3 positive input respectively, 19 resistance R19 other end ground connection GND, 18 resistance R18 one end is connected with first electric capacity C1 one end, the 18 resistance R18 other end is connected with the 20 resistance R20 one end and the 3rd operational amplifier U3 reverse input end respectively, the 20 resistance R20 other end is connected with the 3rd operational amplifier U3 output terminal
7th resistance R7 one end is connected with the first operational amplifier U1 output terminal, the 3rd electric capacity C3 one end ground connection GND, and the 7th resistance R7 other end and the 3rd electric capacity C3 other end connect into node, this node as signal Signal_AB output terminal,
14 resistance R14 one end is connected with the second operational amplifier U2 output terminal, the 6th electric capacity C6 one end ground connection GND, and the 14 resistance R14 other end and the 6th electric capacity C6 other end connect into node, this node as signal Signal_BC output terminal,
21 resistance R21 one end is connected with the 3rd operational amplifier U3 output terminal, and the 9th electric capacity C9 one end ground connection GND, the 21 resistance R21 other end and the 9th electric capacity C9 other end connect into node, and this node is as signal Signal_CA output terminal.
Wherein, the first operational amplifier U1, the second operational amplifier U2 and the 3rd operational amplifier U3 all adopt 12V power supply.
During measurement, be first the sinusoidal weak signal of " line voltage " by three-phase AC detection circuit conditioning by " phase voltage " of three-phase alternating current.Three phase line A phase L_A, B phase L_B, C phase L_C and zero line L_N carry out step-down process by voltage reduction module.The sampled signal of phases line voltage A phase L_A and B phase L_B is accessed the first subtraction circuit module and by first filtration module produce line voltage (L_AB) sinusoidal weak signal Signal_AB; The sampled signal of phases line voltage B phase L_B and C phase L_C is accessed the second subtraction circuit module and by second filtration module produce line voltage (L_BC) sinusoidal weak signal Signal_BC; The sampled signal of phases line voltage C phase L_C and A phase L_A access the 3rd subtraction circuit module is also produced the sinusoidal weak signal Signal_CA of line voltage (L_CA) by the 3rd filter module; The signal optional connection load zero-bit Signal_GND of zero line L_N.
Then, in the time of setting, microprocessor carries out continuous print AD sampling to the line voltage sinusoidal weak signal after conditioning; This step is mainly by analog signal figure, the AD value of every road signal is independently deposited, and the time interval of each AD sampled point can adjust as required in real time, but must ensure that the time interval of all AD sampled points in a resampling process is constant, in the present embodiment, three line voltage AD sampled values are as shown in table 1:
Table 1
Then find signal polarity change location according to table 1, the digital value of inquiry three line voltages, finds the position of change in polarity point in this sampling process of three line voltage signals, and the first time change in polarity point of three line voltages is carried out name placement; Determine that change in polarity point methods is: the AD value of signal is often organized in monitoring, if the polarity of continuous two AD values changes, then thinks that this line voltage signal polarity changes.As " 158 ,-52 " and "-116,118 " of Signal_AB in table 1; "-144,22 " and " 115 ,-76 " of Signal_BC; " 48 ,-169 " and " 67 ,-111 " of Signal_CA.In these group data, the first change in polarity dot sequency of three line voltages is: Signal_CA>Signal_BC>Signal_A B.
Finally, algorithm process is carried out to the sampling AD value in step, three-phase electricity is monitored in real time.
The implementation method of phase sequence monitoring function: judge phase sequence by the first change in polarity dot sequency of real-time inspection three line voltages.As shown in Figure 3, the order in correct phase sequence situation is: Signal_AB-Signal_CA-Signal_BC; As shown in Figure 4, the order in mistake phase sequence situation is: Signal_BC-Signal_CA-Signal_AB.
The implementation method of phase shortage monitoring function: under normal circumstances, as in Figure 3-5, the first change in polarity point of three line voltages is separated from each other and occurs according to fixing order.But in phase shortage situation, as shown in Figure 5, the change in polarity point of wired voltage can overlap, and the direction of the direction of " the change in polarity point " of one of them line voltage and " the change in polarity point " of other two line voltages is contrary.
Line magnitude of voltage measuring method: n sampled point between the first change in polarity point of each line voltage and the 3rd change in polarity point is carried out " all side calculates " (formula is as follows), obtains the effective value of this line voltage.
Judge overvoltage by the effective value comparing three line voltages, whether under-voltage and three-phase balance.
Below be only embody rule example of the present invention, protection scope of the present invention is not constituted any limitation.The technical scheme that all employing equivalents or equivalence are replaced and formed, all drops within rights protection scope of the present invention.
Claims (5)
1. a three-phase AC detection circuit, it is characterized in that, it comprises first, two, three voltage reduction modules, first, two, three subtraction circuit modules and first, two, three filtration modules, described first voltage reduction module input end is connected with the first three-phase alternating current A, output terminal is connected with described first subtraction circuit module positive input and described 3rd subtraction circuit module reverse input end respectively, described second voltage reduction module input end is connected with the second three-phase alternating current B, output terminal is connected with described second subtraction circuit module positive input and described first subtraction circuit module reverse input end respectively, described 3rd voltage reduction module input end is connected with the 3rd three-phase alternating current C, output terminal is connected with described 3rd subtraction circuit module positive input and described second subtraction circuit module reverse input end respectively, described first subtraction circuit module output terminal is connected with described first filtration module input end, described second subtraction circuit module output terminal is connected with described second filtration module input end, described 3rd subtraction circuit module output terminal is connected with described 3rd filtration module input end, described first voltage reduction module earth terminal, described second voltage reduction module earth terminal and described 3rd voltage reduction module ground connection termination signal ground, described first filtration module earth terminal, described second filtration module earth terminal and the equal ground connection of described 3rd filtration module earth terminal, described first filtration module output terminal, described second filtration module output terminal and described 3rd filtration module output terminal are as signal output part.
2. three-phase AC detection circuit according to claim 1, is characterized in that, described 3rd voltage reduction module earth terminal is connected with three-phase alternating current zero line.
3. three-phase AC detection circuit according to claim 1 and 2, is characterized in that,
Described first voltage reduction module, comprise the first resistance, the second resistance and the first electric capacity, described first resistance one end is connected with the first three-phase alternating current, the other end is connected with described second resistance one end and described first electric capacity one end respectively, the described second resistance other end and the described first electric capacity other end all connect signal ground
Described second voltage reduction module, comprise the 8th resistance, the 9th resistance and the 4th electric capacity, described 8th resistance one end is connected with the second three-phase alternating current, the other end is connected with described 9th resistance one end and described 4th electric capacity one end respectively, the described 9th resistance other end and the described 4th electric capacity other end all connect signal ground
Described 3rd voltage reduction module, comprise the 15 resistance, the 16 resistance and the 7th electric capacity, described 15 resistance one end is connected with the 3rd three-phase alternating current, the other end is connected with described 16 resistance one end and described 7th electric capacity one end respectively, the described 16 resistance other end is connected with three-phase alternating current zero line, the described 16 resistance other end and the described 7th electric capacity other end all connect signal ground
Described first subtraction circuit module, comprise the 3rd, four, five and six resistance and the first operational amplifier, described 3rd resistance one end is connected with described first electric capacity one end, the described 3rd resistance other end is connected with described 5th resistance one end and described first operational amplifier positive input respectively, described 5th resistance other end ground connection, described 4th resistance one end is connected with described 4th electric capacity one end, the described 4th resistance other end is connected with described 6th resistance one end and described first operational amplifier reverse input end respectively, the described 6th resistance other end is connected with described first operational amplifier output terminal,
Described second subtraction circuit module, comprise the tenth, 11, 12 and 13 resistance and the second operational amplifier, described tenth resistance one end is connected with described 4th electric capacity one end, the described tenth resistance other end is connected with described 12 resistance one end and described second operational amplifier positive input respectively, described 12 resistance other end ground connection, described 11 resistance one end is connected with described 7th electric capacity one end, the described 11 resistance other end is connected with described 13 resistance one end and described second operational amplifier reverse input end respectively, the described 13 resistance other end is connected with described second operational amplifier output terminal,
Described 3rd subtraction circuit module, comprise the 17, 18, 19 and 20 resistance and the 3rd operational amplifier, described 17 resistance one end is connected with described 7th electric capacity one end, the described 17 resistance other end is connected with described 19 resistance one end and described 3rd operational amplifier positive input respectively, described 19 resistance other end ground connection, described 18 resistance one end is connected with described first electric capacity one end, the described 18 resistance other end is connected with described 20 resistance one end and described 3rd operational amplifier reverse input end respectively, the described 20 resistance other end is connected with described 3rd operational amplifier output terminal,
Described first filtration module, comprises the 7th resistance and the 3rd electric capacity, and described 7th resistance one end is connected with described first operational amplifier output terminal, described 3rd electric capacity one end ground connection, the described 7th resistance other end and the described 3rd electric capacity other end connect into node, and this node is as signal output part
Described second filtration module, comprise the 14 resistance and the 6th electric capacity, described 14 resistance one end is connected with described second operational amplifier output terminal, described 6th electric capacity one end ground connection, the described 14 resistance other end and the described 6th electric capacity other end connect into node, this node is as signal output part
Described 3rd filtration module, comprise the 21 resistance and the 9th electric capacity, described 21 resistance one end is connected with described 3rd operational amplifier output terminal, described 9th electric capacity one end ground connection, the described 21 resistance other end and the described 9th electric capacity other end connect into node, and this node is as signal output part.
4. use a measuring method for three-phase AC detection circuit as claimed in claim 1, it is characterized in that, it comprises the steps:
1) be the sinusoidal weak signal of " line voltage " by " phase voltage " of three-phase alternating current by three-phase AC detection circuit conditioning;
2) in the time of setting, microprocessor carries out continuous print AD sampling to " line voltage " the sinusoidal weak signal after conditioning;
3) to step 2) in sampling AD value carry out algorithm process, three-phase electricity is monitored in real time.
5. three-phase alternating current measuring method according to claim 4, is characterized in that, step 2) described in setting time be greater than half signal period.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201188124Y (en) * | 2008-03-28 | 2009-01-28 | 薛晓明 | Non-induction type phase-exchanging signal detector for brushless DC motor |
| CN201285409Y (en) * | 2008-08-07 | 2009-08-05 | 黑龙江斯福电气有限公司 | Phase voltage detection circuit |
| CN101788615A (en) * | 2010-01-11 | 2010-07-28 | 中色科技股份有限公司 | Simple method for detecting phase sequence of three-phase industrial-frequency alternating current and detection device |
| CN202522633U (en) * | 2012-03-27 | 2012-11-07 | 厦门科华恒盛股份有限公司 | Three-phase voltage open-phase detection circuit of system without zero line |
| CN202583311U (en) * | 2012-04-13 | 2012-12-05 | Tcl空调器(中山)有限公司 | Alternating current zero-crossing detection circuit |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3817814B2 (en) * | 1997-03-05 | 2006-09-06 | 株式会社明電舎 | Main circuit connection judgment method |
| JP4687839B2 (en) * | 2000-04-18 | 2011-05-25 | 株式会社安川電機 | 3-phase power supply phase loss detection circuit |
-
2013
- 2013-06-14 CN CN201310234580.6A patent/CN103760410B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201188124Y (en) * | 2008-03-28 | 2009-01-28 | 薛晓明 | Non-induction type phase-exchanging signal detector for brushless DC motor |
| CN201285409Y (en) * | 2008-08-07 | 2009-08-05 | 黑龙江斯福电气有限公司 | Phase voltage detection circuit |
| CN101788615A (en) * | 2010-01-11 | 2010-07-28 | 中色科技股份有限公司 | Simple method for detecting phase sequence of three-phase industrial-frequency alternating current and detection device |
| CN202522633U (en) * | 2012-03-27 | 2012-11-07 | 厦门科华恒盛股份有限公司 | Three-phase voltage open-phase detection circuit of system without zero line |
| CN202583311U (en) * | 2012-04-13 | 2012-12-05 | Tcl空调器(中山)有限公司 | Alternating current zero-crossing detection circuit |
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