CN112557772A - Small-size alternating current of single power keeps apart detection module - Google Patents
Small-size alternating current of single power keeps apart detection module Download PDFInfo
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- CN112557772A CN112557772A CN202011440629.XA CN202011440629A CN112557772A CN 112557772 A CN112557772 A CN 112557772A CN 202011440629 A CN202011440629 A CN 202011440629A CN 112557772 A CN112557772 A CN 112557772A
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- 238000001514 detection method Methods 0.000 title claims abstract description 36
- 238000002955 isolation Methods 0.000 claims abstract description 39
- 238000000819 phase cycle Methods 0.000 claims abstract description 19
- 238000001914 filtration Methods 0.000 claims abstract description 10
- 230000007935 neutral effect Effects 0.000 claims description 9
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R29/00—Arrangements for measuring or indicating electric quantities not covered by groups G01R19/00 - G01R27/00
- G01R29/16—Measuring asymmetry of polyphase networks
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/02—Measuring effective values, i.e. root-mean-square values
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R19/00—Arrangements for measuring currents or voltages or for indicating presence or sign thereof
- G01R19/165—Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values
- G01R19/16566—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533
- G01R19/1659—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 to indicate that the value is within or outside a predetermined range of values (window)
- G01R19/16595—Circuits and arrangements for comparing voltage or current with one or several thresholds and for indicating the result not covered by subgroups G01R19/16504, G01R19/16528, G01R19/16533 to indicate that the value is within or outside a predetermined range of values (window) with multi level indication
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R23/00—Arrangements for measuring frequencies; Arrangements for analysing frequency spectra
- G01R23/02—Arrangements for measuring frequency, e.g. pulse repetition rate; Arrangements for measuring period of current or voltage
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R25/00—Arrangements for measuring phase angle between a voltage and a current or between voltages or currents
- G01R25/005—Circuits for comparing several input signals and for indicating the result of this comparison, e.g. equal, different, greater, smaller, or for passing one of the input signals as output signal
Abstract
The invention belongs to the technical field of alternating current detection, and discloses a single-power-supply small alternating current isolation detection module which consists of 4 parts including voltage division, filtering and protection, an isolation ADC (analog to digital converter) and a microcontroller, wherein a single power supply of 3.3V is adopted for supplying power, and peak-to-peak value, effective value, period, frequency, phase sequence and phase difference detection are supported. The invention has the advantages of small number of chips, small occupied area and high practical value.
Description
Technical Field
The invention belongs to the technical field of alternating current detection, and relates to a single-power small alternating current isolation detection module.
Background
In order to ensure the working stability of the ac electric equipment, it is often necessary to perform isolation detection on the ac electric signal. The existing AC isolation detection mostly adopts modes such as rectification, a comparator or a non-isolation ADC and the like, and isolation is realized through devices such as an optical coupler and the like, and although the above modes all achieve the purpose of detecting whether AC exists, the following one or more problems exist:
firstly, amplitude, phase sequence and phase difference detection cannot be realized simultaneously;
secondly, the number of chips is large, and the occupied area is large;
and thirdly, the single power supply cannot meet the working requirement, and an isolation power supply needs to be added.
Disclosure of Invention
Objects of the invention
The purpose of the invention is: aiming at various problems of the existing alternating current isolation detection mode, a single-power small alternating current isolation detection module is provided.
(II) technical scheme
In order to solve the technical problem, the invention provides a single-power small alternating current isolation detection module which comprises a voltage division unit, a filtering and protecting unit, an isolation ADC unit and a microcontroller unit.
The voltage division unit consists of 6 voltage division resistors R1-R6, wherein a resistor R1 and a resistor R2 are positioned between an input alternating current X phase and a neutral line N, peak voltage is divided into a range of +/-500 mV, the resistor R3 and a resistor R4 are positioned between an input alternating current Y phase and the neutral line N, the peak voltage is divided into a range of +/-500 mV, and the resistor R5 and the resistor R6 are positioned between an input alternating current Z phase and the neutral line N, so that the peak voltage is divided into a range of +/-32 mV; the input ac X, Y, Z phases may be connected to any of the three phase ac A, B, C phases, respectively.
The filtering and protecting unit is composed of a capacitor and a voltage limiting diode, wherein the capacitor filters high-frequency noise, and the diode is conducted when the voltage is too high to achieve the purpose of voltage limiting.
The isolation ADC is composed of an ADE7913 chip and a related peripheral circuit, and voltage acquisition is carried out on an alternating current X, Y, Z three-phase signal subjected to voltage division, filtering and protection processing through three channels, namely V1P, V2P and IP, of the ADE7913 chip.
The microcontroller unit comprises a microcontroller and a microcontroller peripheral circuit which are powered by a single power supply 3.3V, the microcontroller peripheral circuit is connected with an ADE7913 chip through an SPI bus, and the following functions are completed while instantaneous voltages of three channels of V1P, V2P and IP are read in real time: calculating the peak value and the effective value of an input alternating current signal according to the channel voltage and the proportion of the voltage dividing resistance; judging the phase sequence according to the sequence of the voltage zero crossing points of all phases from negative to positive; calculating a period according to the zero crossing time difference of the voltage from negative to positive; calculating the frequency according to the times of the voltage from negative to positive zero crossing points in unit time; calculating phase difference between phases according to the period and the phase time difference; receiving an external bus instruction, switching a working mode, setting an alarm mode, setting parameters and sending a calculation result.
The alternating current isolation detection module supports the following working modes:
a three-phase standard acquisition mode, namely acquiring X, Y, Z three-phase alternating current signals, judging phase sequences, calculating phase differences among phases, and respectively calculating peak-to-peak values, effective values, periods and frequencies of the phases; in the acquisition mode, when the effective value of the one-phase alternating current signal is lower than the set minimum effective value, the single-phase failure is considered; when the effective values of the two-phase alternating current signals are lower than the set minimum effective value, the two phases are considered to be in phase failure; in the case of two-phase loss, no phase difference is calculated; under the single-phase and two-phase-loss modes, the phase sequence is not judged;
and in the three-phase independent acquisition mode, namely X, Y, Z three-phase alternating current signals are independently acquired, the peak value, the effective value, the period and the frequency of each phase are respectively calculated, and when the effective value of a certain alternating current signal is lower than the set minimum effective value, the phase is considered to be open.
The alternating current isolation detection module supports the following alarm modes:
phase-missing alarm mode, namely, when a certain phase is missing, an alarm is given;
the peak-to-peak undervoltage alarm mode is used for alarming when the peak-to-peak value of a certain alternating current signal is lower than a set peak-to-peak undervoltage alarm value;
the peak-peak value overpressure alarm mode is used for alarming when the peak-peak value of a certain alternating current signal is higher than a set peak-peak value overpressure alarm value;
an effective value under-voltage alarm mode, namely, when the effective value of a certain alternating current signal is lower than a set effective value under-voltage alarm value, alarming is carried out;
an effective value overpressure alarm mode, namely, when the effective value of a certain alternating current signal is higher than a set effective value overpressure alarm value, alarming is carried out;
a phase sequence alarm mode, namely, when the phase sequence is inconsistent with the set normal phase sequence, alarming is carried out; this alarm mode is only effective in the three-phase standard acquisition mode.
A phase difference over-low alarm mode, namely when the phase difference between the specified two phases is lower than the set lower limit of the phase difference threshold value, alarming;
the phase difference overhigh alarm mode is used for alarming when the phase difference between two specified phases is higher than the set upper limit of the phase difference threshold;
in the frequency too low alarm mode, when the frequency value of a certain alternating current signal is lower than the set lower frequency limit, an alarm is given;
the frequency overhigh alarm mode is used for alarming when the frequency value of a certain alternating current signal is higher than the set upper frequency limit;
a combined alarm mode, that is, a combination of the above alarm modes, which alarms when any one of the conditions is satisfied or a plurality of the conditions are simultaneously satisfied;
the alternating current isolation detection module of the invention supports alarming in the following way:
sending alarm data over a bus;
outputting an alarm signal through a designated alarm pin;
the alternating current isolation detection module externally provides the following interfaces:
the alternating current input interface is used for accessing 1-3 paths of single-phase or one path of three-phase four-wire alternating current signals;
the 3.3V power supply interface is used for supplying power to the module;
the bus interface is used for instruction and data transmission;
the alarm interface comprises 3 alarm pins and is used for outputting alarm signals;
(III) advantageous effects
The single-power small-sized alternating current isolation detection module provided by the technical scheme adopts a single power supply of 3.3V to supply power, supports peak-to-peak value, effective value, period, frequency, phase sequence and phase difference detection, and has the advantages of small number of chips, small occupied area and high practical value.
Drawings
FIG. 1 is a block diagram of a single power supply small AC isolation detection module according to the present invention.
FIG. 2 is a schematic diagram of the voltage dividing unit of the small AC isolation detection module with a single power supply.
Detailed Description
In order to make the objects, contents and advantages of the present invention clearer, the following detailed description of the embodiments of the present invention will be made in conjunction with the accompanying drawings and examples.
This embodiment will be described by taking a three-phase ac detection of 115V (up to 140V) as an example.
Referring to fig. 1 and 2, a single power supply small ac isolation detection module is composed of 4 parts including voltage division, filtering and protection, isolation ADC, and microcontroller, wherein:
the voltage dividing unit consists of 6 voltage dividing resistors R1-R6, wherein the resistors R1 and R2 are positioned between an input alternating current X phase and a neutral line N, R1 is 100k omega, and R2 is 250 omega, and the highest peak voltage is divided to about +/-495 mV within +/-500 mV; resistors R3 and R4 are located between the input ac Y phase and the neutral line N, R3 ═ 100k Ω, and R4 ═ 250 Ω, which divide the highest peak voltage to about ± 495mV, within a range of ± 500 mV; resistors R5 and R6 are located between the input ac Z phase and the neutral line N, R5 ═ 100k Ω, and R6 ═ 15 Ω, which divide the highest peak voltage to about ± 30mV, within a range of ± 32 mV. The input ac X, Y, Z phase may be connected to any of the three-phase ac A, B, C phases, respectively, and in this embodiment, the input ac X phase is connected to the three-phase ac a phase, the input ac Y phase is connected to the three-phase ac B phase, and the input ac Z phase is connected to the three-phase ac C phase.
The filtering and protecting unit is composed of a capacitor and a voltage limiting diode, wherein the capacitor filters high-frequency noise, the diode is conducted when the voltage is too high to achieve the purpose of voltage limiting, and the TS4148 diode can be selected.
The isolation ADC is composed of an ADE7913 chip and a related peripheral circuit, and voltage acquisition is carried out on an alternating current X, Y, Z three-phase signal subjected to voltage division, filtering and protection processing through three channels, namely V1P, V2P and IP, of the ADE7913 chip.
The microcontroller part is composed of a microcontroller and related peripheral circuits which are powered by a single power supply 3.3V, and is connected with an ADE7913 chip through an SPI bus, and the microcontroller part can read instantaneous voltages of three channels of V1P, V2P and IP in real time and simultaneously complete the following functions: calculating the peak value and the effective value of an input alternating current signal according to the channel voltage and the proportion of the voltage dividing resistance; judging the phase sequence according to the sequence of the voltage zero crossing points of all phases from negative to positive; calculating a period according to the zero crossing time difference of the voltage from negative to positive; calculating the frequency according to the times of the voltage from negative to positive zero crossing points in unit time; calculating phase difference between phases according to the period and the phase time difference; receiving an external bus instruction, switching a working mode, setting an alarm mode, setting parameters and sending a calculation result.
The embodiment works in a three-phase standard acquisition mode, namely X, Y, Z three-phase alternating current signals are acquired, the phase sequence is judged, the phase difference among phases is calculated, and the peak value, the effective value, the period and the frequency of each phase are calculated respectively; in the acquisition mode, when the effective value of the one-phase alternating current signal is lower than the set minimum effective value, the single-phase failure is considered; when the effective values of the two-phase alternating current signals are lower than the set minimum effective value, the two phases are considered to be in phase failure; in the case of two-phase loss, no phase difference is calculated; in the single-phase and two-phase open-phase modes, phase sequence judgment is not carried out.
The embodiment adopts a phase-loss and effective value overpressure combined alarm mode, the lowest effective value is set to be 80V, the effective value overpressure alarm value is set to be 145V, an alarm signal is output through an alarm pin, and the alarm pin defaults to be a low level; when the X phase is in phase failure or the effective value exceeds 145V, an alarm signal is output through an alarm1 pin, and an alarm1 pin is changed from low to high; when the Y phase is in phase failure or the effective value exceeds 145V, an alarm signal is output through an alarm 2 pin, and the alarm 2 pin is changed from low to high; when the Z phase is out of phase or the effective value exceeds 145V, an alarm signal is output through an alarm 3 pin, and the alarm 3 pin is changed from low to high.
The above description is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present invention, and these modifications and variations should also be regarded as the protection scope of the present invention.
Claims (10)
1. A single power supply small AC isolation detection module, comprising: the voltage division unit, the filtering and protecting unit, the isolating ADC unit and the microcontroller unit are connected in sequence;
the voltage division unit comprises 6 voltage division resistors R1-R6, wherein a resistor R1 and a resistor R2 are positioned between an input alternating current X phase and a neutral line N, peak voltage is divided into a range of +/-500 mV, the resistor R3 and a resistor R4 are positioned between an input alternating current Y phase and the neutral line N, the peak voltage is divided into a range of +/-500 mV, and the resistor R5 and the resistor R6 are positioned between an input alternating current Z phase and the neutral line N, so that the peak voltage is divided into a range of +/-32 mV; the input alternating current X, Y, Z phases are respectively connected with any one of three-phase alternating current A, B, C phases;
the filtering and protecting unit comprises a capacitor and a voltage limiting diode, wherein the capacitor filters high-frequency noise in the three-phase signal transmitted by the voltage dividing unit, and the diode is conducted when the voltage is overhigh to achieve the purpose of limiting the voltage;
the isolation ADC unit comprises an ADE7913 chip and a related peripheral circuit, and voltage acquisition is carried out on an alternating current X, Y, Z three-phase signal subjected to voltage division, filtering and protection processing through three channels, namely V1P, V2P and IP, of the ADE7913 chip;
the microcontroller unit comprises a microcontroller and a microcontroller peripheral circuit which are powered by a single power supply 3.3V, the microcontroller is connected with an ADE7913 chip through an SPI bus, and the following functions are completed while instantaneous voltages of three channels of V1P, V2P and IP are read in real time: calculating the peak value and the effective value of an input alternating current signal according to the channel voltage and the proportion of the voltage dividing resistance; judging the phase sequence according to the sequence of the voltage zero crossing points of all phases from negative to positive; calculating a period according to the zero crossing time difference of the voltage from negative to positive; calculating the frequency according to the times of the voltage from negative to positive zero crossing points in unit time; calculating phase difference between phases according to the period and the phase time difference; receiving an external bus instruction, switching a working mode, setting an alarm mode, setting parameters and sending a calculation result.
2. The single power supply miniature alternating current isolation detection module as claimed in claim 1, wherein the working mode of said alternating current isolation detection module is a three-phase standard acquisition mode: collecting X, Y, Z three-phase alternating current signals, judging phase sequence, calculating phase difference among phases, and respectively calculating peak value, effective value, period and frequency of each phase; in the acquisition mode, when the effective value of the one-phase alternating current signal is lower than the set minimum effective value, the single-phase failure is considered; when the effective values of the two-phase alternating current signals are lower than the set minimum effective value, the two phases are considered to be in phase failure; in the case of two-phase loss, no phase difference is calculated; in the single-phase and two-phase open-phase modes, phase sequence judgment is not carried out.
3. The single power supply small ac isolation detection module of claim 2, wherein the operating mode of the ac isolation detection module is a three-phase independent acquisition mode: separately collecting X, Y, Z three-phase AC signals, respectively calculating peak-to-peak value, effective value, period and frequency of each phase, and when the effective value of a certain AC signal is lower than the set minimum effective value, determining that the phase is open.
4. The single power miniature ac isolation detection module of claim 3, wherein said ac isolation detection module's alarm mode comprises: open phase alarm mode, peak-to-peak undervoltage alarm mode, peak-to-peak overpressure alarm mode, live value undervoltage alarm mode, live value overpressure alarm mode, phase sequence alarm mode, phase difference too low alarm mode, phase difference too high alarm mode, frequency too low alarm mode, frequency too high alarm mode, combination alarm mode.
5. The single power supply miniature ac isolation detection module of claim 4, wherein said open-phase alarm mode is: when a certain phase is lack of phase, alarming; the peak-to-peak undervoltage alarm mode is: when the peak-to-peak value of a certain alternating current signal is lower than a set peak-to-peak value under-voltage alarm value, alarming; peak-to-peak overpressure alarm modes are: and when the peak-to-peak value of a certain alternating current signal is higher than a set peak-to-peak value overpressure alarm value, alarming.
6. The single power supply miniature alternating current isolation detection module of claim 5, wherein said active value under-voltage alarm mode is: when the effective value of a certain alternating current signal is lower than the set effective value under-voltage alarm value, alarming; the effective value overpressure alarm mode is: and when the effective value of a certain alternating current signal is higher than the set effective value overpressure alarm value, alarming.
7. The single power supply miniature ac isolation detection module of claim 6, wherein said phase sequence alarm mode is: when the phase sequence is inconsistent with the set normal phase sequence, alarming; this alarm mode is only effective in the three-phase standard acquisition mode.
8. The single power miniature ac isolation detection module of claim 7 wherein said phase difference too low alarm mode is: when the phase difference between the two phases is lower than the set lower limit of the phase difference threshold, alarming; the phase difference over-high alarm mode is as follows: when the phase difference between the two phases is higher than the upper limit of the set phase difference threshold value, alarming; the low frequency alert mode is: when the frequency value of a certain alternating current signal is lower than the set lower frequency limit, alarming; the too high frequency alert mode is: when the frequency value of a certain alternating current signal is higher than the set upper frequency limit, alarming; the combined alert mode is: in the above combination of a plurality of alarm modes, when any one of the conditions is satisfied or a plurality of the conditions are simultaneously satisfied, an alarm is given.
9. The single power miniature ac isolation test module of claim 8, wherein the ac isolation test module supports alarms by: sending alarm data over a bus; an alarm signal is output through a designated alarm pin.
10. The single-power small ac isolation detection module according to claim 9, wherein the ac isolation detection module provides the following interfaces to the outside:
the alternating current input interface is used for accessing 1-3 paths of single-phase or one path of three-phase four-wire alternating current signals;
the 3.3V power supply interface is used for supplying power to the module;
the bus interface is used for instruction and data transmission;
and the array interface comprises 3 array pins and is used for outputting alarm signals.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202011440629.XA CN112557772A (en) | 2020-12-07 | 2020-12-07 | Small-size alternating current of single power keeps apart detection module |
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| CN202011440629.XA CN112557772A (en) | 2020-12-07 | 2020-12-07 | Small-size alternating current of single power keeps apart detection module |
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2020
- 2020-12-07 CN CN202011440629.XA patent/CN112557772A/en active Pending
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Application publication date: 20210326 |