CN201133914Y

CN201133914Y - Electric energy metering chip double-current comparing structure

Info

Publication number: CN201133914Y
Application number: CNU2007200759135U
Authority: CN
Inventors: 王祥莉; 韩明
Original assignee: Shanghai Beiling Co Ltd
Current assignee: Shanghai Beiling Co Ltd
Priority date: 2007-11-23
Filing date: 2007-11-23
Publication date: 2008-10-15
Anticipated expiration: 2017-11-23

Abstract

The utility model discloses a dual-current comparison structure in an electrical energy metering chip, which is proposed for aiming to the poor anti-electricity-theft performance of the existing electrical energy meter. The dual-current comparison structure comprises the details as follows: the current signals which are inputted into two current channels are sampled and converted into digital signals for obtaining the signal sample module of the sampling current value; the sampling current values are compared and the comparison module of the current value used for metering is outputted; the starting or stopping of a timing module is carried out according to the comparison result of the comparison modules; moreover the current value outputted from the comparison module is contrasted with the preset threshold and a threshold comparator of the current value used for actual metering is outputted. The utility model can realize the detection and the anti-electricity-theft measurement during the current imbalance, thereby assuring the electrical energy metering chip to have the anti-electricity-theft performance, and greatly reducing the fabrication cost of the electricity meter with anti-electricity-theft function in current imbalance.

Description

Double-current comparative structure in a kind of electric energy computation chip

Technical field

The utility model relates to a kind of circuit structure in chip, relates in particular to a kind of double-current comparative structure of realizing anti-electricity-theft electric energy metrical designing requirement in electric energy computation chip.

Background technology

Current, the status of the anti-theft electricity technology of electronic electric energy meter in the electric energy meter industry is more and more important, and the electric energy meter market in country variant, area is all requiring the anti-electricity-theft metering of electric energy meter in varying degrees.The stealing electricity phenomenon that people recognized and the type of anti-theft electricity technology are being on the increase, and all can work out corresponding anti-theft electricity technology at new electricity filching behavior every year.In the electric energy computation chip field, correspondingly require chip to have anti-electricity-theft detection and function of measuring.

Compare with three-phase electric energy meter, single-phase electric energy meter is paid attention to the anti-theft electricity technology of electric energy meter more.Fig. 1 is not for designing the simple single-phase electric energy table model synoptic diagram of anti-stealing electricity function, and it is the current signal of energy measurement live wire and the voltage signal of electric energy meter end of incoming cables only, even and be helpless for very simple electricity filching behavior yet.

Usually current imbalance is presented as the ground connection pattern, and in fact current imbalance comprises the unbalanced situation of the resulting load current of measurement of any live wire and zero line.Stealing may be the bypass segment electric current, and the measured value that causes ammeter is less than actual value.As shown in Figure 2, electricity filching person may be thrown the terminals of ammeter with simple metal wedge 3 into, and this electricity filching behavior ratio is easier to implement.When meter reading was chargeed, electricity filching person can remove the metal wedge 3 of by-pass current in several seconds, so be difficult to detect this stealing mode.

The utility model content

At the problem that prior art exists, the purpose of this utility model is to provide a kind of double-current comparative structure of realizing the anti-stealing electricity function that designs at the electricity filching behavior of current imbalance in electric energy computation chip.

Double-current comparative structure in the electric energy computation chip that the utility model provides comprises: the current signal to two current channels of input is sampled, and is converted to the signal sampling module that digital signal obtains the sample rate current value;

Sample rate current value to described signal sampling module output compares, and exports the comparison module of the current value that is used to measure;

Comparative result according to described comparison module starts or stops timing, and clocking information is fed back to the timing module of described comparison module.

Further, comprise that also current value and the preset threshold value with described comparison module output compares, and export the threshold value comparer of the actual current value that is used for measuring.Because when load is very little, the error-detecting of current imbalance may take place, this should be avoided, so the current value the when threshold value in the preset threshold value comparer is less than the electric energy computation chip operate as normal in the electric energy computation chip.When the current value of comparison module output greater than preset threshold value, current imbalance detects and just works, the current value that the output comparison module is exported; When the current value of comparison module output less than preset threshold value, illustrate that the current value that sampling obtains is little, belong to little loaded work piece, then need to close comparison module, no longer carry out the double-current comparison, comparison module does not switch the current value of output.

Detection and anti-electricity-theft measurement when the double-current comparative structure in the electric energy computation chip that the utility model provides is realized current imbalance, thereby guaranteed that electric energy computation chip has anti-electricity-theft function, reduced the ammeter manufacturing cost of anti-current imbalance stealing greatly; And double-current comparative structure of the present utility model is simple in structure, is easy to realize.

Below in conjunction with accompanying drawing, concrete enforcement of the present utility model is described in further detail.For the person of ordinary skill in the field, to the detailed description of the present utility model, described and other purposes of the present utility model, feature and advantage will be apparent.

Description of drawings

Fig. 1 is the simple single-phase electric energy table model synoptic diagram that does not design anti-stealing electricity function;

Fig. 2 is the single-phase electric energy table model synoptic diagram that adopts the current imbalance electricity filching behavior;

Fig. 3 is the anti-electricity-theft single-phase electric energy table model synoptic diagram of the anti-current imbalance electricity filching behavior of the utility model one preferred implementation;

Fig. 4 is the double-current comparative structure synoptic diagram of the utility model one preferred implementation;

Fig. 5 is the workflow synoptic diagram of the double-current comparative structure of the utility model one preferred implementation.

Embodiment

See also Fig. 3, this is the anti-electricity-theft single-phase electric energy table model synoptic diagram of the anti-current imbalance electricity filching behavior of the utility model one preferred implementation.Detect the just inevitable cost that increases ammeter of imbalance of electric current, must additionally increase a current transformer 4, to realize the current detecting of zero line; Owing to isolating reason, can on the current channel of the first via, select copper-manganese resistance cheaply for use, but another road just must the higher relatively current transformer of use cost.In Fig. 3, the electric energy computation chip 2 in the electronic electric energy meter 1 measures simultaneously through the live wire electric current of copper-manganese resistance sampling with through the neutral line current of current transformer sampling.Under normal circumstances, leakage current is very little, so electric current basically identical in live wire loop and zero line loop, preset the percent value n of the stealing of one two current channel can for electric energy computation chip 2, when the difference of two current values during greater than default percent value n, electric energy computation chip 2 is judged the current imbalance of two current channels, and showing has electricity filching behavior to take place.

See also Fig. 4, this is the double-current comparative structure synoptic diagram of the utility model one preferred implementation.In order to realize the anti-stealing electricity function of electric energy computation chip 2, adopt the sampling of two current channels, and compare the size of current of two current channels automatically, detection and anti-electricity-theft measurement when realizing current imbalance.The double-current comparative structure is made up of signal sampling module 401, comparison module 402, timing module 403, threshold value comparer 404.

Signal sampling module 401 is sampled to the live wire electric current of input and the current signal of neutral line current respectively, and is converted to digital signal, obtains being used for two sample rate current values of comparison.Under normal circumstances, the electric current basically identical in live wire loop and zero line loop can be given tacit consent to the wherein current value of arbitrary passage of comparison module 402 output earlier.402 pairs of sample rate current values through 401 samplings of signal sampling module of comparison module compare, and export the current value that is used to measure, if the difference of the current value of two passages less than preset value, keeps the current value of the former passage of output.When the difference of the current value of two passages surpasses preset value, start timing module 403, if in the schedule time, when the difference of the current value of two passages no longer surpasses preset value, then keep the current value of the former passage of output, timing module 403 zero clearings; If in the schedule time, when the difference of the current value of two passages surpasses preset value all the time, then switch the current value of another passage of output, timing module 403 zero clearings, and there is the signal of the electricity filching behavior of current imbalance in indication.This indication action can be finished by the outer indicator of chip, and this indicator can be pilot lamp, also can similarly can indicate the indicator that has current imbalance for digital indicator or other.Timing module 403 starts or stops according to the comparative result of comparison module, and feeds back to comparison module 403.

Consider in the actual measurement, when load is very little, the error-detecting of current imbalance may take place, this should be avoided, so a threshold value comparer 404 is set, the current value of the threshold value in the electric energy computation chip 2 in the preset threshold value comparers 404 during in this double-current comparative structure less than electric energy computation chip 2 operate as normal.When the current value of comparison module 402 output greater than preset threshold value, current imbalance detects and just works, the current value that output comparison module 402 is exported; When the current value of comparison module 402 output less than preset threshold value, illustrate that the current value of sampling acquisition is little, belong to little loaded work piece, then need to close comparison module 402, no longer carry out double-current relatively, do not switch the current value of output, guarantee to export the actual current value that is used for measuring.

Please in conjunction with Fig. 4 referring to Fig. 5, this is the comparison module 402 workflow synoptic diagram of the double-current comparative structure of the utility model one preferred implementation.The utility model preferably is used for comparison module 402 workflows of double-current comparative structure, mainly is divided into comparison and starts or stops two functions of timing module.

Represent the current value of two current channels sampling gained, at first step 501 respectively with A and B: the current value of comparison module 402 acquiescence output A channels.Carry out step 502 then: the current value of B passage and the current value of A channel are compared, if the current value of B passage smaller or equal to (1+n) of the current value of A channel doubly, n then returns step 501 for a default percent value, and comparison module 402 is still exported the current value of A channel; If the current value of B passage greater than (1+n) of the current value of A channel doubly then carry out step 503, start timing module 403 and carry out timing.Step 504, whether the time that the current value of judging the B passage continues during greater than (1+n) of the current value of A channel times arrives N second, N is the default time, if N second is not arrived in timing, the current value of B passage no longer greater than (1+n) of the current value of A channel doubly, then return step 501, comparison module 402 is still exported the current value of A channel, at this moment the timer zero clearing in the timing module 403; If N second is arrived in timing, the current value of B passage all the time doubly greater than (1+n) of the current value of A channel, step 505 then, comparison module 402 switches the current value of output B passages, timer in the timing module 403 makes zero, and provides the electricity filching behavior that indicator signal represents to exist current imbalance.Step 506: the current value of A channel and the current value of B passage are compared, if the current value of A channel smaller or equal to (1+n) of the current value of B passage doubly then returns step 505, comparison module 402 is still exported the current value of B passage; If the current value of A channel greater than (1+n) of the current value of B passage doubly, then carry out step 507, start timing module 403 and carry out timing, carry out step 508 then, whether the time that the current value of judging A channel continues during greater than (1+n) of the current value of B passage times arrives N second, if N second is not arrived in timing, the current value of A channel no longer greater than (1+n) of the current value of B passage doubly, then return step 505, comparison module 402 is still exported the current value of B passage, the timer zero clearing in the timing module 403; If N second is arrived in timing, the current value of A channel greater than (1+n) of the current value of B passage doubly, then returns step 501 all the time, and comparison module 402 switches the current value of output A channels, timer in the timing module 403 makes zero, and provides the electricity filching behavior that indicator signal represents to exist current imbalance.

Like this, the preferred double-current comparative structure of the utility model has been realized the sampling of two current channels, and compares the size of current of two current channels automatically, detection and anti-electricity-theft measurement when realizing current imbalance.

In sum, detection and anti-electricity-theft measurement when the preferred double-current comparative structure of the utility model is realized current imbalance, thus guaranteed that electric energy computation chip has anti-electricity-theft function, reduce the ammeter manufacturing cost of anti-current imbalance stealing greatly; Whole double-current comparative structure simple in structure is easy to realize.

Certainly; the utility model also can have other embodiment; under the situation that does not deviate from the utility model spirit and essence thereof; the person of ordinary skill in the field works as can make various corresponding changes and distortion according to the utility model, but these corresponding changes and distortion all should belong to the protection domain of claim of the present utility model.

Claims

1, the double-current comparative structure in a kind of electric energy computation chip is characterized in that, comprises

The current signal of two current channels to input is sampled, and is converted to the signal sampling module that digital signal obtains the sample rate current value;

Described sample rate current value is compared, and export the comparison module of the current value that is used to measure;

2, the double-current comparative structure in the electric energy computation chip according to claim 1, it is characterized in that, also comprise the threshold value comparer that is electrically connected with described comparison module, described threshold value comparer compares the current value and the preset threshold value of described comparison module output, when the current value of described comparison module output during greater than described threshold value, described threshold value comparer is exported the current value of described comparison module output; When the current value of described comparison module output during less than described threshold value, described threshold value comparer is closed described comparison module.