CN202372573U - Frequency detection module for radio frequency charge monitoring instrument - Google Patents
Frequency detection module for radio frequency charge monitoring instrument Download PDFInfo
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- CN202372573U CN202372573U CN2011205416509U CN201120541650U CN202372573U CN 202372573 U CN202372573 U CN 202372573U CN 2011205416509 U CN2011205416509 U CN 2011205416509U CN 201120541650 U CN201120541650 U CN 201120541650U CN 202372573 U CN202372573 U CN 202372573U
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Abstract
The utility model discloses a frequency detection module for a radio frequency charge monitoring instrument, and belongs to the field of measurement. The frequency detection module comprises a frequency detection module connected with a control module singlechip, wherein the frequency detection module consists of a first voltage feeding circuit, a second voltage feeding circuit, a third voltage feeding circuit, a superposition circuit and an operational amplifier output circuit; the input ends of the first voltage feeding circuit, the second voltage feeding circuit and the third voltage feeding circuit are correspondingly connected with three phases of voltage sampling ends A, B and C; the output ends of the first voltage feeding circuit, the second voltage feeding circuit and the third voltage feeding circuit are connected with the input end of the operational amplifier output circuit through three corresponding input ends of the superposition circuit; and the output end of the operational amplifier output circuit is connected with the input/output (I/O) port of the control module singlechip. The frequency detection module is used for detecting frequency in a voltage superposition mode; the frequency can be detected under the condition of single-phase voltage, and the frequency detection requirement under the three-phase voltage condition is met; a good precondition is created for modularization and universalization of an intelligent power grid; and the frequency detection module can be widely applied to the field of frequency detection of a power charge monitoring instrument.
Description
Technical field
The utility model belongs to field of measurement, relates in particular to a kind of electric load device for monitoring that is used for.
Background technology
Along with the development of technology and the raising of properties of product, in the observation process of the quality of power supply/power supply management, the use of load monitoring appearance is universal day by day.
Existing load monitoring appearance is generally used for voltage, electric current, active power, power factor (PF), applied power, reactive power, electric energy, the isoparametric measurement of frequency, calculating and demonstration.
Existing load monitoring appearance generally all is furnished with powerful measurement and data processing software, accomplishes measurement, calculating and the demonstration of various measurement parameters, is particularly useful for the measurement and the maintenance of on-the-spot power equipment and supply line.
In carrying out load monitoring and metering process, need the frequency parameter of monitored electrical network be incorporated in the Central Control Module of load monitoring appearance, so that carry out the storage of detection, record, computing and the measurement result of correlation parameter.
Existing load monitoring appearance is to the collection of frequency parameter; The modes that adopt step-by-step counting more; It gathers three-phase voltage and three-phase electricity flow simultaneously through two sampling A, through phaselocked loop (PLL) to the number of accepting and believing frequency carry out synchronized sampling, SF and signal fundamental frequency are changed synchronously.
Though the said frequencies acquisition mode has extensively obtained adopting; But because it need carry out (being usually said A/D conversion) after the digitizing with mains voltage signal (being an analog quantity); Send into again in the single-chip microcomputer of central control module; Handle accordingly and use; And can only detect the frequency of a certain phase in the three-phase supply usually, can not the single-phase double wire system of simultaneous adaptation, the supply line of three-phase three-wire system and three-phase four-wire system, need confirm the concrete frequency detection circuit form of load monitoring appearance to the actual concrete condition of monitored electrical network.
Technique scheme makes the range of application of existing load monitoring appearance product be restricted; Can not adapt to of the requirement of modernized intelligent grid to measurement mechanism " modularization ", " universalization "; Increase the kind and the minimum stored number requirement of which kind of monitoring device and spare part virtually, also had influence on the overall economic efficiency of operation power administrative section.
The utility model content
The utility model technical matters to be solved provides a kind of frequency detection module of radio frequency load monitoring appearance; It adopts the mode of voltage stack to carry out frequency detecting; Not only realized in the frequency detecting of having only under the phase voltage situation, and can satisfy the frequency detecting of three-phase voltage situation simultaneously.
The technical scheme of the utility model is: the frequency detection module that a kind of radio frequency load monitoring appearance is provided; Comprise the frequency detection module that links to each other with the control module single-chip microcomputer, it is characterized in that: described frequency detection module constitutes to tertiary voltage place in circuit, a supercircuit and an amplifier output circuit by first; Said first input end to the tertiary voltage place in circuit is with A, B, the corresponding connection respectively of C three-phase voltage sampling end; Said first the output terminal to the tertiary voltage place in circuit, three corresponding input ends through supercircuit are connected with the input end of amplifier output circuit; The output terminal of said amplifier output circuit is connected with the I/O port of control module single-chip microcomputer.
Concrete, described first to the tertiary voltage place in circuit be voltage amplifier circuit.
Further, above-mentioned voltage amplifier circuit is a discharge circuit.
Its described supercircuit is a voltage overlaying circuit.
Further, above-mentioned voltage overlaying circuit adds resistance by first to triple-lap and constitutes, and said first adds the terminal parallel connection of resistance to triple-lap, is connected with " just " input end of amplifier output circuit; Said first adds the head end of resistance to triple-lap, respectively with the first corresponding connection of output terminal to the tertiary voltage place in circuit.
Its described amplifier output circuit is a voltage amplifier circuit.
Further, above-mentioned voltage amplifier circuit is an operational amplification circuit.
Further, the described first voltage place in circuit comprises the first amplifier U3B, A4, A7 and A8 resistance; The described second voltage place in circuit comprises the second amplifier U3D, B4, B8 and B27 resistance; Described tertiary voltage place in circuit comprises the 3rd amplifier U3C, C4, C7 and C26 resistance; Described supercircuit comprises N7, N8, N9 and N10 resistance; Described amplifier output circuit comprises four high guaily unit U3A, N11, the 76th resistance and N3 and N4 electric capacity.
Wherein, the positive input terminal of the first amplifier U3B is connected with A phase sampler voltage end through A7 resistance, and its negative input end is connected with reference voltage end VREF through A8 resistance, and A4 resistance two ends are connected with output terminal with the negative input end of the first amplifier U3B.
The positive input terminal of the second amplifier U3D is connected with B phase sampler voltage end through B27 resistance, and its negative input end is connected with reference voltage end VREF through B8 resistance, and B4 resistance two ends are connected with output terminal with the negative input end of the second amplifier U3D.
The positive input terminal of the 3rd amplifier U3C is connected with C phase sampler voltage end through C26 resistance, and its negative input end is connected with reference voltage end VREF through C7 resistance, and C4 resistance two ends are connected with output terminal with the negative input end of the 3rd amplifier U3C.
The output terminal of first to the 3rd amplifier; Be connected with the positive input terminal of four high guaily unit U3A through N8, N7, N9 resistance respectively; The negative input end of four high guaily unit U3A is connected with reference voltage end VREF through resistance N10, and the output terminal of four high guaily unit U3A is through the 76th resistance output frequency signal.
The two ends of N11 resistance and N4 electric capacity, between the positive input terminal and ground of four high guaily unit U3A, are connected in series N3 electric capacity at be connected corresponding with output terminal of negative input end with four high guaily unit U3A.
Compare with prior art, the utility model has the advantages that:
1. ABC three-phase voltage sampled value (is realized) stack by three amplifiers of U3B, U3C, U3D among the figure after three times of amplifications; Positive input terminal as amplifier U3A; The negative input end of amplifier U3A is connected with reference voltage VREF, and the frequency of a square wave that obtains like this is exactly the frequency of electrical network;
2. whole frequency detection circuit is simple for structure, and components and parts are few, and working stability is convenient to maintenance, helps to reduce and makes and maintenance cost;
3. adopt the present technique scheme not to be only applicable to have only the situation of a phase voltage, and can satisfy the use occasion of three-phase voltage, make whole frequency detection module have versatility.
Description of drawings
Fig. 1 is the structural representation of the utility model functional module;
Fig. 2 is the wiring diagram of frequency detection module embodiment.
Embodiment
Below in conjunction with accompanying drawing and embodiment the utility model is further specified.
Among Fig. 1; This radio frequency load monitoring appearance mainly comprises power circuit, metering units circuit, frequency detection circuit, harmonic wave processing, MCU core circuit (also claiming central control module, down together), watchdog circuit, data storage and clock circuit, impedance detection output circuit, 485 communicating circuits.
Content by background technology can be known; Mostly existing frequency detection circuit is directly to adopt the A/D translation circuit to obtain the change in voltage of electrical network, carry out digitizing again after, send into again in the single-chip microcomputer of central control module; Handle accordingly and use; And can only detect the frequency of a certain phase in the three-phase supply usually, can not the single-phase double wire system of simultaneous adaptation, the supply line of three-phase three-wire system and three-phase four-wire system, be unfavorable for the needs of modularization, unitized modernized administration of power networks requirement and real work.
Among Fig. 2, the present technique scheme comprises the frequency detection module that links to each other with the control module single-chip microcomputer, and its described frequency detection module constitutes to tertiary voltage place in circuit, a supercircuit and an amplifier output circuit by first; Said first input end to the tertiary voltage place in circuit is with A, B, the corresponding connection respectively of C three-phase voltage sampling end; Said first the output terminal to the tertiary voltage place in circuit, three corresponding input ends through supercircuit are connected with the input end of amplifier output circuit; The output terminal of said amplifier output circuit is connected with the I/O port of control module single-chip microcomputer.
Concrete, described first to the tertiary voltage place in circuit be voltage amplifier circuit, above-mentioned voltage amplifier circuit is a discharge circuit.
Its described supercircuit is a voltage overlaying circuit, and above-mentioned voltage overlaying circuit adds resistance by first to triple-lap and constitutes, and said first adds the terminal parallel connection of resistance to triple-lap, is connected with " just " input end of amplifier output circuit; Said first adds the head end of resistance to triple-lap, respectively with the first corresponding connection of output terminal to the tertiary voltage place in circuit.
Its described amplifier output circuit is a voltage amplifier circuit, and above-mentioned voltage amplifier circuit is an operational amplification circuit.
Further, as shown in the figure, the described first voltage place in circuit comprises the first amplifier U3B, A4, A7 and A8 resistance; The described second voltage place in circuit comprises the second amplifier U3D, B4, B8 and B27 resistance; Described tertiary voltage place in circuit comprises the 3rd amplifier U3C, C4, C7 and C26 resistance; Described supercircuit comprises N7, N8, N9 and N10 resistance; Described amplifier output circuit comprises four high guaily unit U3A, N11, the 76th resistance and N3 and N4 electric capacity.
Wherein, the positive input terminal of the first amplifier U3B is connected with A phase sampler voltage end through A7 resistance, and its negative input end is connected with reference voltage end VREF through A8 resistance, and A4 resistance two ends are connected with output terminal with the negative input end of the first amplifier U3B.
The positive input terminal of the second amplifier U3D is connected with B phase sampler voltage end through B27 resistance, and its negative input end is connected with reference voltage end VREF through B8 resistance, and B4 resistance two ends are connected with output terminal with the negative input end of the second amplifier U3D.
The positive input terminal of the 3rd amplifier U3C is connected with C phase sampler voltage end through C26 resistance, and its negative input end is connected with reference voltage end VREF through C7 resistance, and C4 resistance two ends are connected with output terminal with the negative input end of the 3rd amplifier U3C.
The output terminal of first to the 3rd amplifier; Be connected with the positive input terminal of four high guaily unit U3A through N8, N7, N9 resistance respectively; The negative input end of four high guaily unit U3A is connected with reference voltage end VREF through resistance N10, and the output terminal of four high guaily unit U3A is through the 76th resistance output frequency signal.
The two ends of N11 resistance and N4 electric capacity, between the positive input terminal and ground of four high guaily unit U3A, are connected in series N3 electric capacity at be connected corresponding with output terminal of negative input end with four high guaily unit U3A.
This frequency detection module is used for the detection of grid frequency signal, and whole frequency detection module realizes (U3 among the figure) through an amplifier IC chip.
Three voltage sample values of ABC (are realized) stack by three amplifiers of U3B, U3C, U3D among the figure after three times of amplifications, as the positive input terminal of amplifier U3A.
Three voltages need connect stack resistance (RN7, RN8, RN9) respectively before inserting the amplifier anode; Three the stack resistance resistance have at least one different with other two; If because get identical resistance, the A of three-way four-wire system, B, C phase voltage stack result are 0, for example; The resistance of A, B two mutually desirable tens of k levels, peek the mutually resistance of hundred K levels of C.
The negative input end of amplifier U3A meets reference voltage VREF, and wherein enlargement factor is 2M/1.2K, so output terminal is the saturated value of magnification of positive terminal voltage.Its output waveform is a square wave in fact, can know that through theoretical derivation the frequency of square wave is exactly the frequency of electrical network.Just the frequency of electrical network can have been confirmed as long as detect this frequency.
The present technique scheme adopts said method, has not only realized having only the frequency detecting under the phase voltage situation, and can satisfy the frequency detecting requirement of three-phase voltage situation simultaneously, for good condition precedent has been created in modularization, the universalization of intelligent grid.
The utility model can be widely used in the frequency detecting field of electric load monitor.
Claims (8)
1. the frequency detection module of a radio frequency load monitoring appearance comprises the frequency detection module that links to each other with the control module single-chip microcomputer, it is characterized in that:
Described frequency detection module constitutes to tertiary voltage place in circuit, a supercircuit and an amplifier output circuit by first;
Said first input end to the tertiary voltage place in circuit is with A, B, the corresponding connection respectively of C three-phase voltage sampling end;
Said first the output terminal to the tertiary voltage place in circuit, three corresponding input ends through supercircuit are connected with the input end of amplifier output circuit;
The output terminal of said amplifier output circuit is connected with the I/O port of control module single-chip microcomputer.
2. according to the frequency detection module of the described radio frequency load monitoring of claim 1 appearance, it is characterized in that described first to the tertiary voltage place in circuit be voltage amplifier circuit.
3. according to the frequency detection module of the described radio frequency load monitoring of claim 2 appearance, it is characterized in that described voltage amplifier circuit is a discharge circuit.
4. according to the frequency detection module of the described radio frequency load monitoring of claim 1 appearance, it is characterized in that described supercircuit is a voltage overlaying circuit.
5. according to the frequency detection module of the described radio frequency load monitoring of claim 4 appearance; It is characterized in that described voltage overlaying circuit adds resistance by first to triple-lap and constitutes; Said first adds the terminal parallel connection of resistance to triple-lap, is connected with " just " input end of amplifier output circuit; Said first adds the head end of resistance to triple-lap, respectively with the first corresponding connection of output terminal to the tertiary voltage place in circuit.
6. according to the frequency detection module of the described radio frequency load monitoring of claim 1 appearance, it is characterized in that described amplifier output circuit is a voltage amplifier circuit.
7. according to the frequency detection module of the described radio frequency load monitoring of claim 6 appearance, it is characterized in that described voltage amplifier circuit is an operational amplification circuit.
8. according to the frequency detection module of the described radio frequency load monitoring of claim 1 appearance, it is characterized in that the described first voltage place in circuit comprises the first amplifier U3B, A4, A7 and A8 resistance; The described second voltage place in circuit comprises the second amplifier U3D, B4, B8 and B27 resistance; Described tertiary voltage place in circuit comprises the 3rd amplifier U3C, C4, C7 and C26 resistance; Described supercircuit comprises N7, N8, N9 and N10 resistance; Described amplifier output circuit comprises four high guaily unit U3A, N11, the 76th resistance and N3 and N4 electric capacity;
Wherein, the positive input terminal of the first amplifier U3B is connected with A phase sampler voltage end through A7 resistance, and its negative input end is connected with reference voltage end VREF through A8 resistance, and A4 resistance two ends are connected with output terminal with the negative input end of the first amplifier U3B;
The positive input terminal of the second amplifier U3D is connected with B phase sampler voltage end through B27 resistance, and its negative input end is connected with reference voltage end VREF through B8 resistance, and B4 resistance two ends are connected with output terminal with the negative input end of the second amplifier U3D;
The positive input terminal of the 3rd amplifier U3C is connected with C phase sampler voltage end through C26 resistance, and its negative input end is connected with reference voltage end VREF through C7 resistance, and C4 resistance two ends are connected with output terminal with the negative input end of the 3rd amplifier U3C;
The output terminal of first to the 3rd amplifier; Be connected with the positive input terminal of four high guaily unit U3A through N8, N7, N9 resistance respectively; The negative input end of four high guaily unit U3A is connected with reference voltage end VREF through resistance N10, and the output terminal of four high guaily unit U3A is through the 76th resistance output frequency signal;
The two ends of N11 resistance and N4 electric capacity, between the positive input terminal and ground of four high guaily unit U3A, are connected in series N3 electric capacity at be connected corresponding with output terminal of negative input end with four high guaily unit U3A.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205416509U CN202372573U (en) | 2011-12-21 | 2011-12-21 | Frequency detection module for radio frequency charge monitoring instrument |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN2011205416509U CN202372573U (en) | 2011-12-21 | 2011-12-21 | Frequency detection module for radio frequency charge monitoring instrument |
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| Publication Number | Publication Date |
|---|---|
| CN202372573U true CN202372573U (en) | 2012-08-08 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN2011205416509U Expired - Fee Related CN202372573U (en) | 2011-12-21 | 2011-12-21 | Frequency detection module for radio frequency charge monitoring instrument |
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| Country | Link |
|---|---|
| CN (1) | CN202372573U (en) |
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2011
- 2011-12-21 CN CN2011205416509U patent/CN202372573U/en not_active Expired - Fee Related
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| 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: 20120808 Termination date: 20191221 |