CN2665720Y - Hand-held pincerlike digital current harmonic analyzer - Google Patents
Hand-held pincerlike digital current harmonic analyzer Download PDFInfo
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- CN2665720Y CN2665720Y CN 200320118489 CN200320118489U CN2665720Y CN 2665720 Y CN2665720 Y CN 2665720Y CN 200320118489 CN200320118489 CN 200320118489 CN 200320118489 U CN200320118489 U CN 200320118489U CN 2665720 Y CN2665720 Y CN 2665720Y
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Abstract
The utility model relates to a hand-held pincer-shaped digital current harmonic analyzer which comprises a power supply circuit, an electromagnetic mutual inductor, a sampling circuit, an automatic gear selecting circuit, an adjusting circuit, a digital signal processor, a keyboard circuit and a display circuit. Measuring current signals are obtained by the sampling circuit and are inputted to the digital signal processor by the adjusting circuit to be processed. Measuring value and dynamical displaying harmonic conditions can be displayed on a liquid crystal display by keyboard selection. Meanwhile, the digital signal processor controls the automatic gear selecting circuit to select the measuring range according to the measured processing result feedback. The utility model has the advantages of wide measuring range, accurate measurement, simple, convenient and rapid operation, small volume and portability. The utility model is convenient for the use of an adjusting site.
Description
Technical field
The utility model relates to a kind of digital current harmonic analysis instrument, particularly relates to a kind of pincerlike digital current harmonic analysis instrument of hand-held that is used for testing electric power network harmonic current content.
Background technology
Existing harmonic analysis instrument generally is to adopt mimic channel to realize, the anti-external interference ability of working at the scene, though the employing digital circuit that has, circuit can not be selected the electric current gear automatically.Under little current conditions, just select little electric current gear; Under big current conditions, just select big electric current gear.Select the electric current gear need go artificially to select, select which type of gear just to be difficult to accomplish at the electric current of middle part.On the other hand, the harmonic analysis instrument that uses generally is that large-scale instrument or dependence computing machine are analyzed at present, and volume ratio is bigger, can not carry, be not easy to the power department field monitoring, even there is portable type measuring equipment to use, basically be import, cost an arm and a leg.In addition, also there are some problems in prior art: (1) processing power is poor, but the extension storage space is less, and arithmetic speed is slower, and the algorithm that is difficult to the running precision strictness carries out a large amount of real time data processings; (2) existing processor generally is with 51 series and 96 series monolithics, along with electric system to the improving constantly of real-time, data volume and computing power, these devices can not well adapt to the requirement of electric system aspect computing power; (3) analyser that has does not have communication and control output function, can not satisfy the demand for development of power system networkization, robotization.
The utility model content
The purpose of this utility model is to provide a kind of pincerlike digital current harmonic analysis instrument of hand-held that is used for testing electric power network harmonic current content.
For achieving the above object, the technical scheme that the utility model adopted is: comprise power circuit, the electromagnetic type mutual inductor, metering circuit, digital signal processor, keyboard circuit and LCD display circuit, described metering circuit comprises sample circuit, automatic gear selecting circuit and modulate circuit, sample circuit is made up of sampling resistor R1 and R2, automatically gear selecting circuit master is put pipe T and relay is formed by pushing away, modulate circuit is by operational amplifier A V1, AV2 and additional device are formed, the end of sampling resistor R1 and R2 is connected an end of the secondary of pincers type mutual inductor, the other end of sampling resistor R1 and R2 is connected the other end of the secondary of pincers type mutual inductor through the switch contact of relay, the secondary two ends of pincers type mutual inductor are the positive inverting input of concatenation operation amplifier AV1 also, the normal phase input end of the output terminal concatenation operation amplifier AV2 of operational amplifier A V1, the output terminal of operational amplifier A V2 connects the measurement current signal input port of described digital signal processor, and the range control signal output ends of described digital signal processor connects to push away puts the base stage of managing T.Obtain to measure current signal by sample circuit and be input to digital signal processor processes through modulate circuit, selecting by keyboard can be measured value and show that dynamically the situation of harmonic wave is presented on the LCD, and digital signal processor processes is selected range according to the automatic gear selecting circuit of the result FEEDBACK CONTROL that records simultaneously.
The utility model is connected the filtering circuit of being made up of capacitor C, resistance R C1 and RC2 between the normal phase input end of operational amplifier A V1 and output terminal.
The utility model connects the clamping protective circuit of being made up of diode D1 and D2 at the output terminal of operational amplifier A V2.
The utility model also comprises the communication interface circuit, and the communication interface circuit is connected on the corresponding port of digital signal processor.
The utility model adopts high integrated digital signal processing chip, and that the utility model adopts is TMS320F2407A.
Automatic selection electric current gear described in the utility model adopts digital circuit and software to realize selecting automatically the electric current gear, and the software design program is divided function of initializing module, analog-to-digital conversion functional module, calculation of parameter and index analysis functional module by function.Can be divided into master routine, sampling interruption subroutine, 3 parts of keyboard interrupt subroutine.Master routine is finished the initialization of system, sets various zone bits and corresponding state flag bit, waits for then and interrupting, and judge the setting of keyboard, whether judgment data gathers finishes, intact in data acquisition, carries out computing and obtains various indexs and output to LCD.
Described sampling interruption subroutine, the look-at-me that sampling interruption subroutine response analog-to-digital conversion data-switching finishes, the access sampled data, sampling is calculated, the data sampling that determines whether one-period finishes, and can carry out FFT computing and other evaluation work, control figure signal processing chip DSP timer.
Described keyboard interrupt process flow diagram be to be simplified circuit design, has utilized the I/O of F2407A to carry out the hardware design of Keysheet module.KeyEvent is with interruption form notice digital signal processing chip, the interrupt pin of keyboard is an I/O mouth multiplexing pins, so after the generation of keyboard interrupt incident, this pin is set to the triggering once more that input pin is avoided interrupt event, read this pin level after postponing 30 milliseconds, if level is low, explanation is correct down trigger, otherwise is shake.The function that Keysheet module is finished is mutual between system and the user, allows the user to carry out the operation and the setting of various functional parameters by keyboard.
The utility model principle of work: when measuring electric current after over-sampling circuit is handled, through transforming, obtain the discrete digital sequence of one-period, handle rank rear through window adding technology again and calculate the amplitude of 1-50 subharmonic and the effective value of content and electric current, select the situation that to read any value and show harmonic wave dynamically by keyboard by fast fourier transform.
The beneficial effects of the utility model are: (1) selects the electric current gear automatically, and measurement range is wide, has adopted window adding technology on the algorithm, has prevented spectrum leakage, automatic gear selecting when the 0.5-500A large-range measuring; (2) measure accurately, high-precision electromagnetic type mutual inductor has been adopted in design, and system adopts double-dial way when measuring electric current, measures small-signal with big sampling resistor, measures large-signal and then adopts little sampling resistor, guarantees the precision of measuring; (3) volume is little, adopts the high integrated less peripheral expansion of digital signal processing chip (TMS320F2407A), and is simple in structure, with better function, reduced volume, is easy to carry, easy and simple to handle, measures fast, is convenient to debugging on-the-spot the use; (4) adopt digital circuit and software to realize selecting automatically the electric current gear, can guarantee that the gear of selecting automatically can be the most accurate, more reliable than mimic channel; (5) adopt latest digital signal processor (DSP), the instrument total digitalization, anti-external interference ability is strong; (6) adopt communication interface, and be connected the preservation data with computing machine, LCD shows, the picture image; (7) low cost of manufacture, performance is good, and is lower than import like product price.
Description of drawings
Fig. 1 is the utility model outward appearance front elevation;
Fig. 2 is the utility model system architecture block scheme;
Fig. 3 is the utility model circuit theory diagrams;
Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Figure 10 are the utility model display and key panel start user mode synoptic diagram.
Embodiment
Below in conjunction with drawings and Examples the utility model is described in further detail.
With reference to Fig. 1～2, the utility model mainly comprises electromagnetic type mutual inductor, digital signal processor, keyboard circuit, LCD display circuit, sample circuit, automatic gear selecting circuit, modulate circuit, RS232 communication interface and power circuit.Measure current sample after treatment, transform through A/D, obtain the discrete digital sequence of one-period, handle rank rear through window adding technology again and calculate the amplitude of 1-50 subharmonic and the effective value of content and electric current, select the situation of reading measured value and showing harmonic wave dynamically by keyboard by fast fourier transform.Current measuring range 0.5A-500A, measurement range is wide, adopts high-precision electromagnetic type mutual inductor, error linearity 0.2L.Mutual inductor ratio 1/2000, secondary current are 0.25-250mA, and dynamic range is 1000 times.System adopts double-dial way when measuring electric current, measure small-signal with big sampling resistor, measures large-signal and then adopts little sampling resistor, guarantees the precision of measuring.During sampling, controlling selector channel successively by DSP chip expansion I/O mouth selects, selection principle is: begin open-minded successively from smallest passage, select not surpass the passage of AD measurement range by the voltage maximum, make the signal amplitude of each sampling approach the AD full scale as far as possible like this, improved the precision of measuring, signal through switch is the smaller bipolar signal of amplitude, be not suitable for the AD sampling request, so again through 10 times of amplifications, level promotes, and becomes the signal call number word signal processor that AD can measure in the 0-3V scope and carries out sampling processing.
With reference to Fig. 3, one of the utility model embodiment, it comprises power circuit, the electromagnetic type mutual inductor, metering circuit, digital signal processor, keyboard circuit and LCD display circuit, metering circuit comprises sample circuit, automatic gear selecting circuit and modulate circuit, sample circuit is made up of sampling resistor R1 and R2, automatically the gear selecting circuit is put pipe T and relay J is formed by pushing away, modulate circuit is by operational amplifier A V1, AV2 and additional device are formed, the end of sampling resistor R1 and R2 is connected an end of the secondary of pincers type mutual inductor, the other end of sampling resistor R1 and R2 is connected the other end of the secondary of pincers type mutual inductor through the switch contact of relay J, the secondary two ends of pincers type mutual inductor are the positive inverting input of concatenation operation amplifier AV1 also, the normal phase input end of the output terminal concatenation operation amplifier AV2 of operational amplifier A V1, the output terminal of operational amplifier A V2 connects the measurement current signal input port of described digital signal processor, and the range control signal output ends of digital signal processor connects to push away puts the base stage of managing T.Obtain to measure current signal by sample circuit and be input to digital signal processor processes through modulate circuit, select measured value and show that dynamically the situation of harmonic wave is presented on the LCD by keyboard, digital signal processor processes is according to the automatic gear selecting circuit selection of the result FEEDBACK CONTROL that records range simultaneously.Between the normal phase input end of operational amplifier A V1 and output terminal, be connected the filtering circuit of forming by capacitor C, resistance R C1 and RC2; output terminal at operational amplifier A V2 connects the clamping protective circuit of being made up of diode D1 and D2; the communication interface circuit is connected on the corresponding port of digital signal processor, adopts high integrated digital signal processing chip TMS320F2407A.
Measure electric current I through pincers type mutual inductor, sampling resistor R1 on the mutual inductor secondary and R2 select sample rate current by being connected on digital signal processor DSP, being used for little current sampling resistor is 200 Ω, being used for big current sampling resistor is 5 Ω, the back connects an operational amplifier and capacitor C, resistance R C1 and RC2 and is used for filtering again, eliminate the above high frequency interference of 5KHZ, eliminated high-frequency signal after, signal enters modulate circuit.Modulate circuit is made up of a very wide operational amplifier and an additional device of frequency range, signal enters operational amplifier through RT2, level lifting current potential at the anode warp+3V of operational amplifier, follow the tracks of the unipolar signal of this lifting current potential then through operational amplifier, eliminate high frequency interference through RT4 again, signal condition is become in the scope of 0-3V, simultaneously ambipolar signal is become unipolar signal and accept by DSP.D1 and D2 are holding circuits, prevent that current potential from surpassing the process range of DSP.
Keyboard is made up of 4 keys, restarts key REST, sampling key START, options button CHOOSE, determine key ENTER, 4 keys of keyboard are connected to the IOPE1 of DSP, IOPE2, IOPE3, above the ADCSOC interface, be high level at ordinary times, remain on 3.3V, help anti-interferencely like this, when key is pressed, just make level become low level.According to the variation of level, program is just done corresponding thing.That liquid crystal display LCD selects for use is the graphic lcd module 128*64 in South Asia, model LMA97S005AD.Liquid crystal display LCD is connected on the DSP, connected mode is that the D0-D7 data port of LCD is connected on the IOPB0-7 pin of DSP, D/I is connected on the IOPA2, R/W is connected on the IOPA3, E is connected on the IOPA4, CS1 and CS2 are connected on respectively on IOPA5 and the IOPA6, according to selecting different button operations by keyboard on the LCD picture displayed, want content displayed to be shown on the LCD by the data line handle then.Communication interface is selected RS232 for use, has the PC service routine.Power circuit has adopted the power conversion chip of low-power consumption, selects the 9V powered battery for use, guarantees the stand-by time of battery.DSP and keyboard will adopt the 3.3V power supply, and LCD will adopt the 5V power supply, and modulate circuit is directly powered with 9V.
With reference to Fig. 4, Fig. 5, Fig. 6, Fig. 7, Fig. 8, Fig. 9, Figure 10, the utility model display and key panel start operation instruction are as follows:
(1) start
The LCD picture shows: welcome to use the pincerlike digital current harmonic analysis instrument of hand-held, see Fig. 4.
(2) option
Press down-sampling key START, the picture of LCD picture appearance simultaneously is 4 options, and 4 options are respectively effective value, frequency analysis, spectrum analysis and systematic analysis, see Fig. 5, can determine to enter lower floor by definite key ENTER by the options button CHOOSE selection that circulates:
If 1. select first effective value, to press and determine key ENTER, the picture of appearance is: the effective value XXX.XX that you measure, see Fig. 6, then the effective value of read current.
If 2. select second frequency analysis, to press and determine key ENTER, the picture of appearance is seen Fig. 7, is with that to select overtone order, presses options button and selects overtone order, reads corresponding value by definite key and sees Fig. 8.
If 3. select the 3rd spectrum analysis, to press and determine key ENTER, the picture of appearance is seen Fig. 9.
If 4. select the 4th system's information, to press and determine key ENTER, the picture of appearance is seen Figure 10.
Claims (4)
1. the pincerlike digital current harmonic analysis instrument of hand-held comprises power circuit, electromagnetic type mutual inductor, metering circuit, digital signal processor, keyboard circuit and display circuit, it is characterized in that:
Described metering circuit comprises sample circuit, automatic gear selecting circuit and modulate circuit, sample circuit is made up of sampling resistor R1 and R2, automatically gear selecting circuit master is put pipe T and relay is formed by pushing away, modulate circuit is by operational amplifier A V1, AV2 and additional device are formed, the end of sampling resistor R1 and R2 is connected an end of the secondary of pincers type mutual inductor, the other end of sampling resistor R1 and R2 is connected the other end of the secondary of pincers type mutual inductor through the switch contact of relay, the secondary two ends of pincers type mutual inductor are the positive inverting input of concatenation operation amplifier AV1 also, the normal phase input end of the output terminal concatenation operation amplifier AV2 of operational amplifier A V1, the output terminal of operational amplifier A V2 connects the measurement current signal input port of described digital signal processor, and the range control signal output ends of described digital signal processor connects to push away puts the base stage of managing T.
2. the pincerlike digital current harmonic analysis instrument of hand-held according to claim 1 is characterized in that being connected the filtering circuit of being made up of capacitor C, resistance R C1 and RC2 between the normal phase input end of operational amplifier A V1 and output terminal.
3. the pincerlike digital current harmonic analysis instrument of hand-held according to claim 1 is characterized in that connecting the clamping protective circuit of being made up of diode D1 and D2 at the output terminal of operational amplifier A V2.
4. the pincerlike digital current harmonic analysis instrument of hand-held according to claim 1 is characterized in that comprising the communication interface circuit, and the communication interface circuit is connected on the corresponding port of digital signal processor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200320118489 CN2665720Y (en) | 2003-11-25 | 2003-11-25 | Hand-held pincerlike digital current harmonic analyzer |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 200320118489 CN2665720Y (en) | 2003-11-25 | 2003-11-25 | Hand-held pincerlike digital current harmonic analyzer |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2665720Y true CN2665720Y (en) | 2004-12-22 |
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ID=34347326
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 200320118489 Expired - Fee Related CN2665720Y (en) | 2003-11-25 | 2003-11-25 | Hand-held pincerlike digital current harmonic analyzer |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2665720Y (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102221643A (en) * | 2011-06-14 | 2011-10-19 | 中国矿业大学 | Converter harmonic detector of direct current mine hoist |
| CN101839936B (en) * | 2009-03-19 | 2013-09-25 | 北京普源精电科技有限公司 | Current measurement device |
| CN105891601A (en) * | 2016-06-23 | 2016-08-24 | 中国人民解放军63888部队 | Harmonic component assistant testing device |
-
2003
- 2003-11-25 CN CN 200320118489 patent/CN2665720Y/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101839936B (en) * | 2009-03-19 | 2013-09-25 | 北京普源精电科技有限公司 | Current measurement device |
| CN102221643A (en) * | 2011-06-14 | 2011-10-19 | 中国矿业大学 | Converter harmonic detector of direct current mine hoist |
| CN105891601A (en) * | 2016-06-23 | 2016-08-24 | 中国人民解放军63888部队 | Harmonic component assistant testing device |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |