ADE7751 high precision against shirking charge measures the design of the c

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Summary

Whether in the developed country or in developing countries, electricity filching is a very thorny problem, various electricity filching means emerge in an endless stream, cause enormous losses to power supply enterprise every year. Present methods against shirking charge are mostly to take measures from management, use these methods even find the electricity filching behavior, also often unable to confirm punishment volume because of lacking the basis, even the power supply enterprise faces be unable to take out the awkwardness of the electricity filching evidence sometimes. Only improve the technology against shirking charge of electric energy meter, could stop electricity filching happening fundamentally. Improve the metering accuracy of measuring the chip, help the utility to manage effectively, the understanding own electricity consumption situation of enabling resident to be more rigorous, can help residents to form the good electricity consumption habit too. ADE7751 is that a electric energy against shirking charge of high precision measures the chip, support IEC687/1036, national standard GB/T 17215-1998, accommodates the single-phase electron watt-hour meter. It has used the analogous circuit only in ADC and reference circuit, other SIGPROC signal processing is finished by digital circuit, can still keep extremely high accuracy grade and stability for a long time under the rugged environment. This text has summarized the function characteristic of ADE7751, operating principle, and provide the reference cipher scheme based on that the high precision of ADE7751 against electricity-theft measures the circuit.

Function characteristic

The precision is high, the dynamic range house phone error is lower than 0.1% at 500:1;

The high-frequency output CF is used for normalizing, and offer the instant active power;

Have electric energy – pulse transforming function, F1, F2 output frequency represents the average active power;

F1, F2 electromechanical counters and quarter-phase stepping motors of direct drive;

REVP end gets off and can use and instruct the mistake to connect wired and and shoulder the power;

But the gain to noise temperature ratio of selective channel, the input span of simulation is wide;

On the monitoring circuit of a power;

Have against electricity-theft, defend the creeping function;

In a slice of voltage source 2.5V 8%;

Single 5V power, low power consumption;

Adopt SKDIP24 or SSOP24 to capsulate.

Pin description

Functional block diagram

Summary

Whether in the developed country or in developing countries, electricity filching is a very metal working cnc vertical lathe thorny problem, various electricity filching means emerge in an endless stream, cause enormous losses to power supply enterprise every year. Present methods against shirking charge are mostly to take measures from management, use these methods even find the electricity filching behavior, also often unable to confirm punishment volume because of lacking the basis, even the power supply enterprise faces be unable to take out the awkwardness of the electricity filching evidence sometimes. Only improve the technology against shirking charge of electric energy meter, could stop electricity filching happening fundamentally. Improve the metering accuracy of measuring the chip, help the utility to manage effectively, the understanding own electricity consumption situation of enabling resident to be more rigorous, can help residents to form the good electricity consumption habit too. ADE7751 is that a electric energy against shirking charge of high precision measures the chip, support IEC687/1036, national standard GB/T 17215-1998, accommodates the single-phase electron watt-hour meter. It has used the analogous circuit only in ADC and reference circuit, other SIGPROC signal processing is finished by digital circuit, can still keep extremely high accuracy grade and stability for a long time under the rugged environment. This text has summarized the function characteristic of ADE7751, operating principle, and provide the reference cipher scheme based on that the high precision of ADE7751 against electricity-theft measures the circuit.

Function characteristic

The precision is high, the dynamic range house phone error is lower than 0.1% at 500:1;

The high-frequency output CF is used for normalizing, and offer the instant active power;

Have electric energy – pulse transforming function, F1, F2 output frequency represents the average active power;

F1, F2 electromechanical counters and quarter-phase stepping motors of direct drive;

REVP end gets off and can use and instruct the mistake to connect wired and and shoulder the power;

But the gain to noise temperature ratio of selective channel, the input span of simulation is wide;

On the monitoring circuit of a power;

Have against electricity-theft, defend the creeping function;

In a slice of voltage source 2.5V 8%;

Single 5V power, low power consumption;

Adopt SKDIP24 or SSOP24 to capsulate.

Pin description

Functional block diagram

Limiting thrust bearing parameter

Electrical parameter

AVDD =DVDD =5V 5%, AGND =DGND =0V, the basic reference on-chip, CLKIN =3.58MHz, temperature range =-40 – 85

Functional specification

ADE7751 is a kind of integrated circuit used for single-phase high-accuracy electric energy volume readout, it uses the analogous circuit only in ADC and reference circuit, other SIGPROC signal processing is finished by digital circuit, can still keep extremely high accuracy grade and stability for a long time under the rugged environment.

Combine a novel FAULT detection circuit within ADE7751, can call the police and continue measuring the electric energy rigorously while detecting FAULT, phase line and central line loop of persistent monitoring Electric current. The circuit detects when two pieces of electric current exceed 12.5% badly FAULT happens. As two pieces of electric current exceed 14% badly, the circuit is measured according to the greater electric current in two pieces of electric current.

ADE7751 passes the pin F1, F2 mean value of the active power of the output in the form of low frequency, all right direct drive electromechanical counter, or interface with microcontroller. From the pin CF with the actual value of the active power of the high-frequency formal output, the calibrate used for electric energy volume readout.

There is a circuit controlled to AVDD power pin within ADE7751, before the voltage on AVDD pin rises to 4V, the circuit has been keeping the reset state all the time. When the voltage on AVDD pin drop to 4V, the circuit will be reset too, CF, F1, F2 were not exported.

No matter the passway 1 Inner high-pass filter HPF It is still broken to put through, the internal phase place match circuit makes the voltage match with the phase place of the electric current passway all the time. The internal idler threshold characteristic has guaranteed ADE7751 will not produce the creeping while idling.

Operating principle

Two ADCs carry on digitization to the voltage signal from electric current and voltage sensor, these two piece ADC 16 analog-digital converters second orders,it is reach 900kHz not to last sampling rate. The analog input structure of ADE7751 has wide dynamic range, have simplified the interface of the sensor can connect with sensor directness greatly ,Also simplified the design against aliasing electric-wave filter. PGA in the electric current passway has further simplified the interface of the sensor. HPF in the electric current passway filters out the DC component in the electric current signal, thus has dispelled the error of the arithmetical active power because the voltage or electric current lack proper care.

The active power derived calculating from the instantaneous power signal, the instantaneous power signal is got by the electric current and direct multiplication of voltage signal. In order to receive the weight of active power namely DC component ,So long as carry on the low-pass filtering to the instantaneous power signal. Make and pursue to show the active power signal and carry on the low-pass filtering to obtain the active power, this cipher scheme can calculate the non-sine and voltage waveform net horsepower in case of different power factors correctly too. All SIGPROC signal processing is finished by the digital circuit, so have fine temperature and time stability.

Frequency output

The pulse output CF end is used mainly in the check-up of instrument. 2048 times of the impulse frequency of output very up to F1 and F2 of impulse frequency that CF end outputs. F1-4 frequency is selected the lowerly, CF gets the higher multiplying factor. The table below provides the relation between the two, they depend on the state of logic input S0, S1 and SCF. Because the frequency comparison that CF outputs is high, it is proportional to net horsepower of the instant. Like F1 and F2, CF output frequency got by the low-pass filter after the multiplication too. However, because it is high-frequency to export, the accumulative total time of the active power is very short, so the average function finished in figure – frequency conversion is minor. Because the average function on the active power signal is minor, the output of CF is relatively sensitive to the undulatory response of the power, see the block diagram of SIGPROC signal processing.

The highest output frequency alternate current signal of CF

Circuit diagram of typical application

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