CN103487626A - Measuring circuit - Google Patents

Abstract

The invention relates to the field of power grid measurement, in particular to a measuring circuit. The measuring circuit is characterized by comprising a CS 5463-ISZ chip arranged on an MCU single chip microcomputer, a capacitor C6 is connected between a pin VIN+ and a pin VIN- of the CS 5463-ISZ chip, one end of the capacitor C6 is connected with one end of a resistor R8, the other end of the resistor R8 is connected with one fixed end of a potentiometer W2, the other fixed end of the potentiometer W2 is connected with one end of a resistor R9, the other end of the resistor R9 is connected to the other end of the capacitor C6, a capacitor C4 and a capacitor C5 are connected between one end of the resistor R8 and the other end of the resistor R9 in series. The measuring circuit has the advantages of being capable of accurately measuring and metering active electric energy, instantaneous power, current effective values, voltage effective values, current instantaneous values and voltage instantaneous values, and more importantly capable of measuring reactive factors, frequency factors, power factors and the like, and improves sampling measurement accuracy, output voltage stability and degree of distortion of an output waveform.

Description

a measuring circuit

technical field

The invention relates to the field of power grid measurement, in particular to a measurement circuit.

Background technique

Traditional power grid ammeters generally use pointer-type meters, and they all have shortcomings such as small measurement range, poor stability, low precision, inconvenient reading and large errors, etc., which no longer meet the needs of social development. With the rapid development of intelligent measurement and control technology. The advantages of the digital ammeter with the single-chip microcomputer as the core are very obvious. As an indispensable part of the intelligent measurement and control system, the measurement circuit has higher and higher design requirements. In the design, we abandoned the traditional phase-locked loop frequency synthesis technology and directly used TMS320F2812 to directly generate pulse width modulation signals. Such effective value sampling and instantaneous value sampling have very high requirements, and the traditional A/D sampling chip can no longer meet the requirements, which affects the sampling measurement accuracy, output voltage stability, and output waveform distortion, and cannot be corrected during measurement. Measurement of power, frequency and power factor.

Contents of the invention

The purpose of the present invention is to provide a measurement circuit to solve the problem that the ammeter and other devices currently used for power grid measurement cannot meet the requirements of accuracy and output voltage stability, and the output waveform is easily distorted, and the reactive power, frequency, and The problem of measuring power factor.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical solutions: a measurement circuit, comprising a CS5463-ISZ chip installed on an MCU single-chip microcomputer,

A capacitor C6 is connected between the pin VIN+ and the pin VIN- of the CS5463-ISZ chip, one end of the capacitor C6 is connected to one end of the resistor R8, and the other end of the resistor R8 is connected to a fixed end of the potentiometer W2, and the potentiometer The other fixed end of W2 is connected to one end of resistor R9, the other end of resistor R9 is connected to the other end of capacitor C6, and capacitor C4 and capacitor C5 are connected in series between one end of resistor R8 and the other end of resistor R9. The sliding end of the potentiometer W2 is connected between the capacitor C4 and the capacitor C5 and grounded, and the two fixed ends of the potentiometer W2 are connected to the secondary of the transformer T2;

A capacitor C9 is connected between the pin IIN+ and the pin IIN- of the CS5463-ISZ chip, one end of the capacitor C9 is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to a fixed end of the potentiometer W1, the potentiometer The other fixed end of W1 is connected to one end of resistor R14, the other end of resistor R14 is connected to the other end of capacitor C9, and capacitor C7 and capacitor C8 are connected in series between one end of resistor R13 and the other end of resistor R14. The potentiometer The sliding end of W1 is connected between the capacitor C7 and the capacitor C8 and grounded, and the two fixed ends of the potentiometer W1 are connected to the secondary of the transformer T3;

Both the primary stage of the transformer T2 and the primary stage of the transformer T3 are connected to the main circuit of the power grid.

A further technical solution is that the resistance values of the resistor R8, the resistor R9, the resistor R13 and the resistor R14 are all 472Ω, the capacitance values of the capacitor C4, the capacitor C5, the capacitor C7 and the capacitor C8 are all 220PF, and the variable The resistance of the positioner W1 and the positioner W2 is 2KΩ.

A further technical solution is that an oscillator Y1 is connected between the pin XOUT and the pin XIN of the CS5463-ISZ chip.

A further technical solution is that the frequency of the oscillator Y1 is 4.096MHZ.

A further technical solution is that the pin VD+ of the CS5463-ISZ chip is grounded through a capacitor C3, a resistor R4 is connected between the pin VD+ and the pin VA+, the pin VA+ is connected to one end of the resistor R2, and the resistor The other end of R2 is connected to one end of resistor R1, and the other end of resistor R1 is respectively connected to the cathode of diode D1 and the cathode of diode D2, and one end of resistor R2 is also connected to the cathode of diode D3, and the anode of diode D is connected to The other end of the resistor R2, the anode of the diode D is connected to the pin VA+ through the capacitor C2, the pin PFMON of the CS5463-ISZ chip is connected to the other end of the resistor R1 through the resistor R3, and grounded through the resistor R5, the diode The secondary of transformer T1 is connected between the anode of D1 and the anode of diode D2.

A further technical solution is that the resistance value of the resistor R1 is 200Ω, the resistance value of the resistor R2 is 200Ω, the resistance value of the resistor R3 is 5KΩ, the resistance value of the resistor R4 is 100Ω, the resistance value of the resistor R5 is 1KΩ, and the capacitor The capacitance value of C1 is 100μF, the capacitance value of capacitor C2 is 50μF, the capacitance value of capacitor C3 is 100μF, the type of diode D1 and diode D2 is IN4007, and the type of diode D3 is 2CW53.

A further technical solution is that both the pin VREFIN and the pin VREFOUT of the CS5463-ISZ chip are grounded through the capacitor C10, and the pin VA- and the pin DGEN are both grounded.

A further technical solution is that the capacitance of the capacitor C10 is 0.1 μF.

Compared with the prior art, the beneficial effect of the present invention is: it can accurately measure and measure active electric energy, instantaneous power, current effective value, voltage effective value, current instantaneous value, voltage instantaneous value, more importantly, it also has the function of measuring reactive power , frequency, power factor and other characteristics, greatly improve the sampling measurement accuracy, output voltage stability, output waveform distortion.

Description of drawings

Fig. 1 is a connection schematic diagram of a measurement circuit of the present invention.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

Fig. 1 has shown an embodiment of a kind of measuring circuit of the present invention: a kind of measuring circuit comprises the CS5463-ISZ chip installed on the MCU single-chip microcomputer,

A capacitor C6 is connected between the pin VIN+ and the pin VIN- of the CS5463-ISZ chip, one end of the capacitor C6 is connected to one end of the resistor R8, and the other end of the resistor R8 is connected to a fixed end of the potentiometer W2, and the potentiometer The other fixed end of W2 is connected to one end of resistor R9, the other end of resistor R9 is connected to the other end of capacitor C6, and capacitor C4 and capacitor C5 are connected in series between one end of resistor R8 and the other end of resistor R9. The sliding end of the potentiometer W2 is connected between the capacitor C4 and the capacitor C5 and grounded, and the two fixed ends of the potentiometer W2 are connected to the secondary of the transformer T2;

A capacitor C9 is connected between the pin IIN+ and the pin IIN- of the CS5463-ISZ chip, one end of the capacitor C9 is connected to one end of the resistor R13, and the other end of the resistor R13 is connected to a fixed end of the potentiometer W1, the potentiometer The other fixed end of W1 is connected to one end of resistor R14, the other end of resistor R14 is connected to the other end of capacitor C9, and capacitor C7 and capacitor C8 are connected in series between one end of resistor R13 and the other end of resistor R14. The potentiometer The sliding end of W1 is connected between the capacitor C7 and the capacitor C8 and grounded, and the two fixed ends of the potentiometer W1 are connected to the secondary of the transformer T3;

Both the primary stage of the transformer T2 and the primary stage of the transformer T3 are connected to the main circuit of the power grid.

According to a preferred embodiment of a measurement circuit of the present invention, the resistance values of the resistor R8, the resistor R9, the resistor R13 and the resistor R14 are all 472Ω, and the capacitance values of the capacitor C4, capacitor C5, capacitor C7 and capacitor C8 are all is 220PF, and the resistance of the displacer W1 and W2 is 2KΩ. Capacitor C4, capacitor C5, resistor R8, and resistor R9 are symmetrically set on the voltage sampling channel, which enhances the anti-radio frequency interference of the CS5463-ISZ chip. Capacitor C7, capacitor C8, resistor R14, and resistor R14 are symmetrically set on the current sampling channel, which helps In order to reduce the sensitivity of the CS5463-ISZ chip to radio frequency interference, it also improves the sampling measurement accuracy, and the potentiometer W1 plays the role of adjusting the size of the sampling signal.

According to another embodiment of the measurement circuit of the present invention, an oscillator Y1 is connected between the pin XOUT and the pin XIN of the CS5463-ISZ chip. According to another preferred embodiment of a measurement circuit of the present invention, the frequency of the oscillator Y1 is 4.096MHZ.

According to another embodiment of a measurement circuit of the present invention, the pin VD+ of the CS5463-ISZ chip is grounded through a capacitor C3, a resistor R4 is connected between the pin VD+ and the pin VA+, and the pin VA+ is connected to One end of the resistor R2, the other end of the resistor R2 is connected to one end of the resistor R1, the other end of the resistor R1 is respectively connected to the cathode of the diode D1 and the cathode of the diode D2, and one end of the resistor R2 is also connected to the cathode of the diode D3, and the cathode of the diode D The anode of the diode D is connected to the other end of the resistor R2 through the capacitor C1, the anode of the diode D is connected to the pin VA+ through the capacitor C2, and the pin PFMON of the CS5463-ISZ chip is connected to the other end of the resistor R1 through the resistor R3. R5 is grounded, and the secondary of the transformer T1 is connected between the anode of the diode D1 and the anode of the diode D2. According to another preferred embodiment of a measurement circuit of the present invention, the resistance value of the resistor R1 is 200Ω, the resistance value of the resistor R2 is 200Ω, the resistance value of the resistor R3 is 5KΩ, the resistance value of the resistor R4 is 100Ω, and the resistance value of the resistor R5 The resistance value of the capacitor is 1KΩ, the capacitance value of the capacitor C1 is 100μF, the capacitance value of the capacitor C2 is 50μF, the capacitance value of the capacitor C3 is 100μF, the type of the diode D1 and the diode D2 is IN4007, and the type of the diode D3 is 2CW53.

According to another embodiment of the measurement circuit of the present invention, the pin VREFIN and the pin VREFOUT of the CS5463-ISZ chip are both grounded through the capacitor C10, and the pin VA- and the pin DGEN are both grounded. According to another preferred embodiment of a measurement circuit of the present invention, the capacitance value of the capacitor C10 is 0.1 μF.

Preferably, the pins RESET, pin CS, pin SDI, pin SD0, and pin SCLK of the CS5463-ISZ chip are respectively connected to the RESET interface, the IOB0 interface, the IOB1 interface, the IOB2 interface, and the IOB3 interface of the MCU microcontroller. ; The pin CPUCLK, pin INT, pin EDIR and pin EOUT of the CS5463-ISZ chip are empty.

The working principle of the present invention is: the voltage signal is introduced into the pins VIN+ and VIN- of the CS5463-ISZ chip through the rear pole circuit of the transformer T2, and the voltage information is collected, sorted, and measured;

The current signal is introduced into the pins IIN+ and IIN- of the CS5463-ISZ chip through the transformer T3 for current information collection and measurement processing.

TI and the rear pole circuit are the power supply circuit of the CS5463-ISZ chip. It enters the CS5463-ISZ chip through the pins VA+ and VD+, and the pin XOUT and pin XIN of the oscillator Y1 are connected to the CS5463-ISZ chip to ensure that the CS5463-ISZ chip function that works normally.

Although the invention has been described herein with reference to a number of illustrative embodiments thereof, it is to be understood that numerous other modifications and implementations can be devised by those skilled in the art which will fall within the scope of the disclosure disclosed in this application. within the scope and spirit of the principles. More specifically, within the scope of the disclosure, drawings and claims of the present application, various modifications and improvements can be made to the components and/or layout of the subject combination layout. In addition to variations and modifications to the component parts and/or layout, other uses will be apparent to those skilled in the art.

Claims (8)

1. a metering circuit is characterized in that: comprise the CS5463-ISZ chip be arranged on the MCU single-chip microcomputer,

Be connected with capacitor C 6 between the pin VIN+ of described CS5463-ISZ chip and pin VIN-, the end of one end contact resistance R8 of described capacitor C 6, the other end of resistance R 8 connects the stiff end of potentiometer W2, the end of another stiff end contact resistance R9 of potentiometer W2, the other end of resistance R 9 is connected to the other end of capacitor C 6, be serially connected with capacitor C 4 and capacitor C 5 between the other end of an end of resistance R 8 and resistance R 9, the sliding end of described potentiometer W2 is connected between capacitor C 4 and capacitor C 5 and ground connection, two stiff ends of described potentiometer W2 are connected on transformer T2 secondary,

Be connected with capacitor C 9 between the pin IIN+ of described CS5463-ISZ chip and pin IIN-, the end of one end contact resistance R13 of described capacitor C 9, the other end of resistance R 13 connects the stiff end of potentiometer W1, the end of another stiff end contact resistance R14 of potentiometer W1, the other end of resistance R 14 connects the other end of capacitor C 9, be serially connected with capacitor C 7 and capacitor C 8 between the other end of an end of resistance R 13 and resistance R 14, the sliding end of described potentiometer W1 is connected between capacitor C 7 and capacitor C 8 and ground connection, two stiff ends of described potentiometer W1 are connected on transformer T3 secondary,

The main of the main of described transformer T2 and transformer T3 all is connected on the electric power network main circuit.

2. a kind of metering circuit according to claim 1, it is characterized in that: the resistance of described resistance R 8, resistance R 9, resistance R 13 and resistance R 14 is 472 Ω, the capacitance of described capacitor C 4, capacitor C 5, capacitor C 7 and capacitor C 8 is 220PF, and the resistance of described deflection machine W1 and deflection machine W2 is 2K Ω.

3. a kind of metering circuit according to claim 1, is characterized in that: between the pin XOUT of described CS5463-ISZ chip and pin XIN, be connected with oscillator Y1.

4. a kind of metering circuit according to claim 3, it is characterized in that: the frequency of described oscillator Y1 is 4.096MHZ.

5. a kind of metering circuit according to claim 1, it is characterized in that: the pin VD+ of described CS5463-ISZ chip is by capacitor C 3 ground connection, be connected with resistance R 4 between described pin VD+ and pin VA+, the end of described pin VA+ contact resistance R2, the end of the other end contact resistance R1 of resistance R 2, the other end of resistance R 1 connects respectively the negative pole of diode D1 and the negative pole of diode D2, one end of described resistance R 2 also is connected to the negative pole of diode D3, the positive pole of diode D is connected to the other end of resistance R 2 by capacitor C 1, the positive pole of described diode D is connected to pin VA+ by capacitor C 2, the pin PFMON of described CS5463-ISZ chip is connected to the other end of resistance R 1 by resistance R 3, by resistance R 5 ground connection, be connected with the secondary of transformer T1 between the positive pole of the positive pole of described diode D1 and diode D2.

6. a kind of metering circuit according to claim 5, it is characterized in that: the resistance of described resistance R 1 is 200 Ω, the resistance of resistance R 2 is 200 Ω, and the resistance of resistance R 3 is 5K Ω, and the resistance of resistance R 4 is 100 Ω, the resistance of resistance R 5 is 1K Ω, the capacitance of capacitor C 1 is 100 μ F, and the capacitance of capacitor C 2 is 50 μ F, and the capacitance of capacitor C 3 is 100 μ F, the model of diode D1 and diode D2 is IN4007, and the model of diode D3 is 2CW53.

7. a kind of metering circuit according to claim 1 is characterized in that: the pin VREFIN of described CS5463-ISZ chip and pin VREFOUT be all by capacitor C 10 ground connection, pin VA-and the equal ground connection of pin DGEN.

8. a kind of metering circuit according to claim 7, it is characterized in that: the capacitance of described capacitor C 10 is 0.1 μ F.

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