CN203759116U - Intelligent electric meter with fundamental-wave metering function - Google Patents
Intelligent electric meter with fundamental-wave metering function Download PDFInfo
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- CN203759116U CN203759116U CN201420163045.6U CN201420163045U CN203759116U CN 203759116 U CN203759116 U CN 203759116U CN 201420163045 U CN201420163045 U CN 201420163045U CN 203759116 U CN203759116 U CN 203759116U
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Abstract
The utility model relates to intelligent electric meters, in particular to an intelligent electric meter with a fundamental-wave metering function. The intelligent electric meter comprises a voltage changer, a current changer, a DSP (digital signal processor), an LCD (liquid crystal display) and a communication chip. Measured analog voltage signals and measured analog current signals are converted into digital signals by the aid of an A/D (analog/digital) converter of the DSP, the digital voltage signals and the digital current signals are subjected to low-pass filtering processing respectively by the aid of a CPU (central processing unit) of the DSP, fundamental-wave voltage values and fundamental-wave current values are extracted and are multiplied with one another, and then sums of the fundamental-wave voltage values and the fundamental-wave current values are calculated, so that measured power values can be acquired. The intelligent electric meter has the advantages that the intelligent electric meter is simple in structure, metering chips can be omitted, accordingly, the integral cost of the intelligent electric meter can be reduced, and the intelligent electric meter has complicated metering and managing functions.
Description
Technical field
The utility model relates to intelligent electric meter, specifically a kind of intelligent electric meter with first-harmonic function of measuring.
Background technology
Intelligent electric meter is a kind of taking computer technology and mechanics of communication as basis, the measuring apparatus of energy information being carried out to data sampling and processing and management.Because intelligent electric meter has electric energy metrical, information storage, network communication, Real-Time Monitoring, automatically controls and the function such as information interaction, can realize " flow of power, information flow, the Business Stream " two-way interaction between electrical network and user, thereby raising power consumption efficiency is one of infrastructure device building intelligent grid.
The theory diagram of existing intelligent electric meter as shown in Figure 1, is made up of four parts such as computation chip, microcontroller, communication chip and LCD display.Computation chip theory diagram wherein as shown in Figure 2, is made up of voltage changer, power pack, multiplier and voltage/frequency transducer four parts.Voltage changer in computation chip and power pack are respectively by tested voltage u with tested current i converts corresponding low-voltage to and little electric current is delivered in multiplier, the instantaneous value that multiplier completes voltage and current multiplies each other, export a DC voltage being directly proportional to the average power in a period of time, and then by voltage/frequency transducer, convert the DC voltage of multiplier output to corresponding pulse duration frequency signal.The pulse duration frequency signal counting of microcontroller to computation chip output, and show corresponding electric energy by LCD display.Communication chip is used for carrying out exchanges data with miscellaneous equipment, checks meter, arranges table meter parameter etc.
There is in actual applications following shortcoming in existing intelligent electric meter:
(1) there is no harmonic wave harmful in filtering electrical network.Directly the instantaneous value of tested voltage and tested electric current is directly multiplied each other, what obtain is fundamental energy and harmonic electric energy sum, and anharmonic wave user's electric energy measurement data is increased, and harmonic wave user's electric energy measurement data reduces on the contrary.
(2) accuracy of electric energy metrical is difficult to improve.The computing of the multiplier in computation chip and voltage/frequency transducer, the accuracy of conversion and stability directly affect the accuracy of intelligent electric meter electric energy metrical.
(3) computation chip has increased complicacy and the hardware cost of intelligent electric meter system.
Utility model content
For above-mentioned technical matters, the utility model proposes a kind of simple in structure, measure intelligent electric meter accurately, concrete technical scheme is:
An intelligent electric meter with first-harmonic function of measuring, comprises,
Voltage changer, for being divided into 220V alternating voltage the required input voltage of A/D analog to digital converter that is applicable to DSP digital signal processor;
Power pack, for being converted to phase line alternating current the required input voltage of A/D analog to digital converter that is applicable to DSP digital signal processor;
DSP digital signal processor, for being converted to discrete digital signal by the analog voltage signal of voltage changer and power pack output; And discrete digital signal is carried out to low-pass filtering treatment, extract fundamental voltage value and fundamental current value; Finally fundamental voltage value and fundamental current value are multiplied each other and sued for peace, obtain power measurement values;
LCD display, for showing all kinds of numerical value of power, voltage, electric current, time, remaining sum of DSP digital signal processor output;
Communication chip, for DSP digital signal processor and miscellaneous equipment communication.
Wherein, DSP(Digital Singnal Processor) first the A/D analog to digital converter of digital signal processor Embedded be converted to digital voltage signal and digital current signal by tested analog voltage and tested analog current, CPU in DSP digital signal processor carries out respectively low-pass filtering to digital voltage signal and digital current signal, extract the fundamental signal in tested voltage signal and tested current signal, and then tested voltage fundamental signal and tested current first harmonics signal are carried out to multiplying processing, thereby realize the Measurement accuracy of power.
The intelligent electric meter measuring method with first-harmonic function of measuring the utility model proposes, comprises the following steps:
(1) to tested analog voltage
uwith tested analog current
isample, obtain discrete digital voltage signal
u(t)with digital current signal
i(t),
tfor sampling instant,
t=1,2,3;
(2) to discrete digital voltage signal
u(t)with discrete digital current signal
i(t)carry out respectively low-pass filtering treatment, formula calculates respectively discrete digital voltage signal calculated as described below
u(t)with discrete digital current signal
i(t)the moving average that counts
u ma (t)with
i ma (t):
（1）
（2）
In formula (1) and formula (2):
u ma (t)it is the digital voltage signal of t phase
u(t)the moving average that counts,
u (t-i+1)be
t-i+1the digital voltage signal value of phase;
i ma (t)it is the digital current signal of t phase
i(t)the moving average that counts,
i (t-i+1)be
t-i+1the digital current signal value of phase;
tfor sampling instant,
mfor the computation period number of the moving average that counts,
mvalue be generally 1/4 of measured signal primitive period T;
(3) by the digital voltage signal of synchronization
u(t)the moving average that counts
u ma (t), digital current signal
i(t)the moving average that counts
i ma (t)multiply each other and sue for peace again, can obtain the mean value of active power in one-period
p(t),
（3）
In formula (3)
nfor the sampled point quantity in measured signal primitive period T.
The utility model that adopts technique scheme, compared with prior art, its outstanding feature is:
Intelligent electric meter uses DSP digital signal processor to carry out analog to digital conversion, low-pass filtering treatment and multiplying, has not only simplified intelligent electric meter structure, and has saved computation chip and reduced device holistic cost, can realize complicated metering and management function simultaneously.The intelligent electric meter measuring method with first-harmonic function of measuring the utility model proposes, first tested simulating signal is carried out to digital sample and low-pass filtering treatment, filter harmonic electric quantity, carry out power calculation according to the fundametal compoment signal extracting from measured signal, thereby eliminated harmonic electric energy and have a strong impact on the problem of electric energy metrical degree of accuracy.
Brief description of the drawings
Fig. 1 is the theory diagram of existing intelligent electric meter.
Fig. 2 is the computation chip theory diagram in existing intelligent electric meter.
Fig. 3 is the intelligent electric meter theory diagram that the utlity model has first-harmonic function of measuring.
Fig. 4 is the measurement procedure block diagram that the utlity model has the intelligent electric meter measuring method of first-harmonic function of measuring.
Embodiment
Below in conjunction with embodiment, the utility model is described in further detail, and object is only better to understand the utility model content.Therefore, the cited case unrestricted protection domain of the present utility model.
What the present embodiment provided has first-harmonic function of measuring intelligent electric meter, and its theory diagram as shown in Figure 3, comprises voltage changer, power pack, DSP digital signal processor, LCD display and communication chip.
Voltage changer, is applicable to the required input voltage of A/D analog to digital converter for 220V alternating voltage is divided into.In the present embodiment, the output terminal of voltage changer is connected with the A/D analog to digital converter input end of DSP digital signal processor;
Power pack, is applicable to the required input voltage of A/D analog to digital converter for phase line alternating current is converted to.The output terminal of power pack is connected with the A/D analog to digital converter input end of DSP digital signal processor;
DSP digital signal processor, for being converted to discrete digital signal by the analog voltage signal of voltage changer and power pack output; And it is carried out to low-pass filtering treatment, extract fundamental voltage value and fundamental current value; Finally fundamental voltage value and fundamental current value are multiplied each other and sued for peace, obtain power measurement values.
LCD display, for showing all kinds of numerical value such as power, voltage, electric current, time, remaining sum of DSP digital signal processor output.The GPIO(General Purpose Input Output of LCD display and DSP digital signal processor) general input/output port is connected;
Communication chip, is used for carrying out exchanges data with miscellaneous equipment, checks meter, arranges table meter parameter etc.Communication chip is connected with the GPIO general input/output port of DSP digital signal processor.
Described in the present embodiment, in intelligent electric meter, voltage changer adopts precision resistance bleeder circuit; Power pack adopts precision resistance divided circuit; DSP digital signal processor adopts the TMS320C2802 digital signal processor of American TI Company, and Embedded has 12 A/D analog to digital converters and 32 bit CPUs of 16 passages; Communication chip adopts RS485/ infrared communication chip.
Described in the present embodiment, the principle of work of intelligent electric meter is as shown in Figure 4:
Voltage changer and power pack convert tested voltage u and tested current i to corresponding low voltage signal respectively and deliver to the A/D analog to digital converter input end in DSP digital signal processor; The analog voltage signal of voltage changer and power pack output is converted to discrete digital signal by A/D analog to digital converter; First to the digital signal of A/D analog to digital converter output, it carries out low-pass filtering treatment to CPU in DSP digital signal processor, extract fundamental voltage value and fundamental current value, then fundamental voltage value and fundamental current value are multiplied each other and sued for peace, obtain power measurement values, finally result is demonstrated.
The measuring method of intelligent electric meter described in the present embodiment, comprises the following steps:
(1) to tested analog voltage
uwith tested analog current
isample, by analog voltage
uwith tested analog current
ibe converted to discrete digital voltage signal
u(t)with discrete digital current signal
i(t),
tfor sampling instant,
t=1,2,3;
(2) to digital voltage signal
u(t)with digital current signal
i(t)carry out respectively low-pass filtering treatment, formula calculates respectively digital voltage signal calculated as described below
u(t)with digital current signal
i(t)the moving average that counts
u ma (t)with
i ma (t):
In formula:
u ma (t)it is the digital voltage signal of t phase
u(t)the moving average that counts,
u (t-i+1)be
t-i+1the digital voltage signal value of phase;
i ma (t)it is the digital current signal of t phase
i(t)the moving average that counts,
i (t-i+1)be
t-i+1the digital current signal value of phase;
tfor sampling instant,
mfor the computation period number of the moving average that counts,
mvalue be generally 1/4 of measured signal primitive period T;
(3) by the digital voltage signal of synchronization
u(t)the moving average that counts
u ma (t), digital current signal
i(t)the moving average that counts
i ma (t)multiply each other and sue for peace again, can obtain the mean value of active power in one-period
p(t),
In formula
nfor the sampled point quantity in measured signal primitive period T.
Claims (1)
1. an intelligent electric meter with first-harmonic function of measuring, is characterized in that: comprises,
Voltage changer, for being divided into 220V alternating voltage the required input voltage of A/D analog to digital converter that is applicable to DSP digital signal processor;
Power pack, for being converted to phase line alternating current the required input voltage of A/D analog to digital converter that is applicable to DSP digital signal processor;
DSP digital signal processor, for being converted to discrete digital signal by the analog voltage signal of voltage changer and power pack output; And discrete digital signal is carried out to low-pass filtering treatment, extract fundamental voltage value and fundamental current value; Finally fundamental voltage value and fundamental current value are multiplied each other and sued for peace, obtain power measurement values;
LCD display, for showing all kinds of numerical value of power, voltage, electric current, time, remaining sum of DSP digital signal processor output;
Communication chip, for DSP digital signal processor and miscellaneous equipment communication.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN201420163045.6U CN203759116U (en) | 2014-04-04 | 2014-04-04 | Intelligent electric meter with fundamental-wave metering function |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420163045.6U CN203759116U (en) | 2014-04-04 | 2014-04-04 | Intelligent electric meter with fundamental-wave metering function |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103852637A (en) * | 2014-04-04 | 2014-06-11 | 唐山紫光智能电子有限公司 | Intelligent electric meter with fundamental wave metering function and measurement method thereof |
-
2014
- 2014-04-04 CN CN201420163045.6U patent/CN203759116U/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103852637A (en) * | 2014-04-04 | 2014-06-11 | 唐山紫光智能电子有限公司 | Intelligent electric meter with fundamental wave metering function and measurement method thereof |
| CN103852637B (en) * | 2014-04-04 | 2015-07-01 | 唐山紫光智能电子有限公司 | Intelligent electric meter with fundamental wave metering function and measurement method thereof |
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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 |
Granted publication date: 20140806 Termination date: 20180404 |
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| CF01 | Termination of patent right due to non-payment of annual fee |