CN211453891U - Power failure detection circuit of power quality device - Google Patents
Power failure detection circuit of power quality device Download PDFInfo
- Publication number
- CN211453891U CN211453891U CN201920624495.3U CN201920624495U CN211453891U CN 211453891 U CN211453891 U CN 211453891U CN 201920624495 U CN201920624495 U CN 201920624495U CN 211453891 U CN211453891 U CN 211453891U
- Authority
- CN
- China
- Prior art keywords
- circuit
- input
- voltage
- resistor
- operational amplifier
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000001514 detection method Methods 0.000 title claims abstract description 17
- 238000002955 isolation Methods 0.000 claims abstract description 88
- 238000006243 chemical reaction Methods 0.000 claims abstract description 81
- HEZMWWAKWCSUCB-PHDIDXHHSA-N (3R,4R)-3,4-dihydroxycyclohexa-1,5-diene-1-carboxylic acid Chemical compound O[C@@H]1C=CC(C(O)=O)=C[C@H]1O HEZMWWAKWCSUCB-PHDIDXHHSA-N 0.000 claims abstract description 77
- 230000003287 optical effect Effects 0.000 claims abstract description 51
- 230000008878 coupling Effects 0.000 claims abstract description 29
- 238000010168 coupling process Methods 0.000 claims abstract description 29
- 238000005859 coupling reaction Methods 0.000 claims abstract description 29
- 239000003990 capacitor Substances 0.000 claims description 60
- 238000001914 filtration Methods 0.000 claims 1
- 238000010586 diagram Methods 0.000 description 12
- 230000006870 function Effects 0.000 description 4
- 238000005034 decoration Methods 0.000 description 2
- 230000005611 electricity Effects 0.000 description 2
- 230000000630 rising effect Effects 0.000 description 1
Images
Landscapes
- Dc-Dc Converters (AREA)
Abstract
The utility model discloses a power-down detection circuit of an electric energy quality device, which comprises a DCDC boost isolation power circuit, a primary side voltage acquisition circuit, a level conversion circuit and an optical coupling isolation circuit; the input end of the DCDC boosting isolation power supply circuit is connected with a voltage power supply, and the output end of the DCDC boosting isolation power supply circuit is respectively connected with the input end of the primary side voltage acquisition circuit and the input end of the level conversion circuit; the output end of the primary side voltage acquisition circuit is connected with the input end of the level conversion circuit, the output end of the level conversion circuit is connected with the input end of the optical coupling isolation circuit, and the output end of the optical coupling isolation circuit is connected with the processor.
Description
Technical Field
The utility model relates to a power quality device technical field especially relates to a power quality device falls electric detection circuitry.
Background
At present, along with the rapid development of the power grid, the demand of user power consumption increases and the requirement on power quality is higher and higher, and power quality device wide application carries out power quality's detection in the middle of the power grid, because power quality device itself needs external power source to supply power, and under the occasion of no UPS, the power grid outage makes power quality device fall the power, leads to power quality data can't in time preserve.
Disclosure of Invention
The utility model provides a power quality device falls electric detection circuitry, the problem that can effectively prior art power quality device power quality data can't carry out timely saving when falling the electricity can realize once side voltage and secondary side voltage isolation, realizes detecting interchange, the direct current power supply power condition of falling simultaneously, reliable and stable.
In order to achieve the above object, an embodiment of the present invention provides a power failure detection circuit for an electric energy quality device, including a DCDC boost isolation power circuit, a primary side voltage acquisition circuit, a level conversion circuit, and an optical coupling isolation circuit;
the input end of the DCDC boosting isolation power supply circuit is connected with a voltage power supply, and the output end of the DCDC boosting isolation power supply circuit is respectively connected with the input end of the primary side voltage acquisition circuit and the input end of the level conversion circuit;
the output end of the primary side voltage acquisition circuit is connected with the input end of the level conversion circuit, the output end of the level conversion circuit is connected with the input end of the optical coupling isolation circuit, and the output end of the optical coupling isolation circuit is connected with the processor.
Preferably, the DCDC boost isolation power supply circuit comprises a voltage input circuit, a voltage output circuit and a DCDC isolator;
the input end of the voltage input circuit is connected with the input end of the DCDC boosting isolation power supply circuit; a first output end of the voltage input circuit is connected with a first input end of the DCDC isolator, and a second output end of the voltage input circuit is connected with a second input end of the DCDC isolator; the second input end of the DCDC isolator is grounded;
a first input end of the voltage output circuit is connected with a first output end of the DCDC isolator, and a second input end of the voltage output circuit is connected with a second output end of the DCDC isolator; the output end of the voltage output circuit is connected with the second output end of the DCDC isolator and the output end of the DCDC boosting isolation power supply circuit; the first output terminal of the DCDC isolator is grounded.
Further, the voltage input circuit comprises a first capacitor and a second capacitor;
the first end of the first capacitor is respectively connected with the input end of the voltage input circuit and the first output end of the voltage input circuit, and the second end of the first capacitor is connected with the second output end of the voltage input circuit; the second capacitor is electrically connected in parallel to two ends of the first capacitor.
Furthermore, the voltage output circuit comprises a first resistor and a third capacitor;
one end of the third capacitor is connected with the first input end of the voltage output circuit, and the other end of the third capacitor is connected with the second input end of the voltage output circuit; the first resistor is electrically connected in parallel with two ends of the third capacitor.
Preferably, the primary side voltage acquisition circuit comprises an operational amplifier difference circuit and a voltage raising circuit;
the input end of the primary side voltage acquisition circuit is respectively connected with the first input end of the operational amplifier difference circuit and the input end of the voltage lifting circuit;
the output end of the voltage lifting circuit is connected with the second input end of the operational amplifier difference calculating circuit;
a third input end and a fourth input end of the operational amplifier difference calculating circuit are respectively connected with an external power supply;
the output end of the voltage lifting circuit and the output end of the operational amplifier difference calculating circuit are respectively connected with the output end of the primary side voltage collecting circuit.
Further, the voltage boost circuit comprises a second resistor, a third resistor and a first operational amplifier;
one end of the second resistor is connected with the input end of the voltage lifting circuit, and the other end of the second resistor is connected with the first input end of the first operational amplifier;
one end of the third resistor is connected with the first input end of the first operational amplifier, and the other end of the third resistor is grounded;
the second input end of the first operational amplifier is connected with the output end of the first operational amplifier;
the output end of the first operational amplifier is connected with the output end of the voltage lifting circuit.
Furthermore, the operational amplifier difference calculating circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second operational amplifier, a fourth capacitor and a fifth capacitor;
one end of the fourth resistor is connected with the second input end of the operational amplifier difference calculating circuit, and the other end of the fourth resistor is connected with the first input end of the second operational amplifier;
one end of the fifth resistor is connected with the third input end of the operational amplifier difference calculating circuit, and the other end of the fifth resistor is connected with the first input end of the second operational amplifier;
one end of the sixth resistor is connected with the fourth input end of the operational amplifier difference calculating circuit, and the other end of the sixth resistor is connected with the second input end of the second operational amplifier;
one end of the seventh resistor is connected with the second input end of the second operational amplifier, and the other end of the seventh resistor is connected with the output end of the second operational amplifier;
the fifth capacitor is electrically connected to two ends of the seventh resistor in parallel;
a third input end of the second operational amplifier is respectively connected with a first input end of the operational amplifier difference calculating circuit and a first end of the fourth capacitor; a second end of the fourth capacitor is grounded;
a fourth input end of the second operational amplifier is grounded;
and the output end of the second operational amplifier is connected with the output end of the operational amplifier difference calculating circuit.
Preferably, the level shift circuit includes a threshold voltage input circuit, a sixth capacitor, an eighth resistor, and a level shift chip;
the output end of the DCDC boosting isolation power supply circuit is connected with the first input end and the fourth input end of the level switching circuit;
a first interface of the level conversion chip is connected with a first input end of the level conversion circuit and a first end of a sixth capacitor, and a second end of the sixth capacitor is grounded;
a second input end of the level conversion circuit is connected with an output end of the voltage lifting circuit, and a third input end of the level conversion circuit is connected with an output end of the operational amplifier difference calculating circuit;
a second input end of the level conversion circuit is connected with a first input end of the threshold voltage input circuit, a third input end of the level conversion circuit is connected with a second input end of the threshold voltage input circuit, a first output end of the threshold voltage input circuit is connected with a second interface of the level conversion chip, and a second output end of the threshold voltage input circuit is connected with a third interface of the level conversion chip;
a fourth input end of the level conversion circuit is connected with a fourth interface of the level conversion chip;
one end of the eighth resistor is connected with the fifth interface of the level conversion chip, and the other end of the eighth resistor is grounded;
a sixth interface of the level conversion chip is grounded; and a seventh interface of the level conversion chip is connected with the output end of the level conversion circuit.
Further, the threshold voltage input circuit includes a seventh capacitor, a ninth resistor, and a tenth resistor;
a first end of the ninth resistor is connected with the second input end of the threshold voltage input circuit, and a second end of the ninth resistor is connected with the second output end of the threshold voltage input circuit;
one end of the tenth resistor is connected with the second end of the ninth resistor, and the other end of the tenth resistor is grounded;
one end of the seventh capacitor is connected with the first output end of the threshold voltage input circuit, and the other end of the seventh capacitor is connected with the second output end of the threshold voltage input circuit.
Preferably, the optical coupler isolation circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor and an optical coupler;
one end of the eleventh resistor is connected with the input end of the optical coupler isolation circuit, and the other end of the eleventh resistor is connected with the first port of the optical coupler; the second port and the third port of the optical coupler are grounded;
a fourth port of the optical coupler is connected with a first end of the twelfth resistor, a first end of the thirteenth resistor and an output end of the optical coupler isolation circuit; a second end of the twelfth resistor is connected with a voltage power supply; a second end of the thirteenth resistor is grounded.
Compared with the prior art, the utility model discloses a power quality device power-down detection circuit, through power quality device power-down detection circuit includes DCDC boost isolation power supply circuit, primary side voltage acquisition circuit, level conversion circuit, opto-coupler isolation circuit; the input end of the DCDC boosting isolation power supply circuit is connected with a voltage power supply, and the output end of the DCDC boosting isolation power supply circuit is respectively connected with the input end of the primary side voltage acquisition circuit and the input end of the level conversion circuit; the output end of the primary side voltage acquisition circuit is connected with the input end of the level conversion circuit, the output end of the level conversion circuit is connected with the input end of the optical coupling isolation circuit, the output end of the optical coupling isolation circuit is connected with the processor, when the power quality device is powered off, the DCDC boost isolation power supply circuit isolates a system voltage power supply of the power quality device and supplies power to the primary side voltage acquisition circuit and the level conversion circuit, the primary side voltage acquisition circuit converts an external power supply supplied with power by the power quality device into a threshold voltage according to a certain proportion and transmits the threshold voltage to the level conversion circuit, the level conversion circuit adjusts and outputs a level signal according to the threshold voltage, the optical coupling isolation circuit transmits the output level signal of the level conversion circuit to the processor of the power quality device after optical coupling isolation, and the processor detects the system power off, therefore, the data of the power quality device is stored in a time delay manner, the problem that the power quality data cannot be stored in time when the power quality device in the prior art is powered down can be solved, the primary side voltage and the secondary side voltage can be isolated, the power down condition of an alternating current power supply and a direct current power supply can be detected simultaneously, and the power down detection circuit is stable and reliable.
Drawings
Fig. 1 is a schematic structural diagram of a power failure detection circuit of an electric energy quality device in an embodiment of the present invention;
fig. 2 is a circuit diagram of a DCDC boost isolated power supply circuit in an embodiment of the present invention;
fig. 3 is a circuit diagram of an operational amplifier differencing circuit in an embodiment of the present invention;
fig. 4 is a circuit diagram of a voltage boost circuit in an embodiment of the present invention;
fig. 5 is a circuit diagram of a level shift circuit according to an embodiment of the present invention;
fig. 6 is a circuit diagram of the optical coupling isolation circuit in the embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.
Referring to fig. 1, which is a schematic structural diagram of a power-down detection circuit of an electric energy quality device in an embodiment of the present invention, the power-down detection circuit of the electric energy quality device includes a DCDC boost isolation power circuit 100, a primary side voltage acquisition circuit 200, a level conversion circuit 300, and an optical coupling isolation circuit 400;
the input end of the DCDC boost isolation power supply circuit 100 is connected to a voltage power supply, and the output end of the DCDC boost isolation power supply circuit 100 is connected to the input end of the primary side voltage acquisition circuit 200 and the input end of the level shift circuit 300 respectively;
the output end of the primary side voltage acquisition circuit 200 is connected with the input end of the level conversion circuit 300, the output end of the level conversion circuit 300 is connected with the input end of the optical coupling isolation circuit 400, and the output end of the optical coupling isolation circuit 400 is connected with the processor.
It should be noted that, when the power quality device is powered down, the DCDC boost isolation power supply circuit 100 isolates the system voltage power supply of the power quality device and supplies power to the primary side voltage acquisition circuit 200 and the level conversion circuit 300, the primary side voltage acquisition circuit 200 converts an external power supply supplied by the power quality device into a threshold voltage according to a certain proportion and transmits the threshold voltage to the level conversion circuit 300, then the level conversion circuit 300 adjusts an output level signal according to the threshold voltage, and then the optical coupling isolation circuit 400 transmits the output level signal of the level conversion circuit 300 to the processor of the power quality device after optical coupling isolation, so that the processor detects the system power failure, and stores the data of the power quality device in a time delay.
Preferably, referring to fig. 2, it is a circuit diagram of the DCDC boost isolation power supply circuit 100 in the embodiment of the present invention, where the DCDC boost isolation power supply circuit 100 includes a voltage input circuit 101, a voltage output circuit 102 and a DCDC isolator U1;
the input end VCC of the voltage input circuit 101 is connected with the input end of the DCDC boost isolation power supply circuit 100; a first output terminal of the voltage input circuit 101 is connected to a first input terminal of the DCDC isolator U1, and a second output terminal of the voltage input circuit 101 is connected to a second input terminal of the DCDC isolator U1; a second input terminal of the DCDC isolator U1 is grounded;
a first input terminal of the voltage output circuit 102 is connected to a first output terminal of the DCDC isolator U1, and a second input terminal of the voltage output circuit 102 is connected to a second output terminal of the DCDC isolator U1; the output end of the voltage output circuit 102, the second output end of the DCDC isolator U1 and the output end V of the DCDC boost isolation power supply circuit 100aConnecting; the first output of the DCDC isolator U1 is connected to ground.
Preferably, the voltage input circuit 101 comprises a first capacitor C1 and a second capacitor C2;
a first end of the first capacitor C1 is connected to the input terminal VCC of the voltage input circuit and the first output terminal of the voltage input circuit 101, respectively, and a second end of the first capacitor C1 is connected to the second output terminal of the voltage input circuit 101; the second capacitor C2 is electrically connected in parallel across the first capacitor C1.
Preferably, the voltage output circuit 102 includes a first resistor R1 and a third capacitor C3;
one end of the third capacitor C3 is connected to the first input end of the voltage output circuit 102, and the other end is connected to the second input end of the voltage output circuit 102; the first resistor R1 is electrically connected in parallel across the third capacitor C3.
It can be understood that the DCDC boost isolated power supply circuit 100 is used to supply power to the primary side voltage acquisition circuit 200 and the level conversion circuit. The DCDC isolator U1 is used for realizing the isolated conversion of the system voltage power supply 3.3V into the voltage source 5V. The first input end of the DCDC isolator is a Vin positive electrode interface, specifically a 3.3V voltage input end, and the second input end of the DCDC isolator is a Vin negative electrode interface and is connected with the ground. The system voltage supply 3.3V is input to the DCDC isolator U1 through the voltage input circuit 101. The first output terminal and the second output terminal of the DCDC isolator U1 are 5V voltage output terminals, and the DCDC isolator U1 converts the voltage supply VCC _3V3 on the secondary side of the system of the power quality device into VCC _ PW5V0 output voltage on the primary side. And is transmitted to the output end V of the DCDC boost isolated power supply circuit 100 through the voltage output circuit 102aThe voltage output circuit 102 functions as a filter. Therefore, the isolation of the primary side circuit and the secondary side circuit can be effectively realized, and the internal system circuit of the electric energy quality device is protected.
Preferably, the primary side voltage acquisition circuit 200 includes an operational amplifier difference circuit 201 and a voltage boost circuit 202;
the input terminal of the primary side voltage collecting circuit 200 is respectively connected with the first input terminal V of the operational amplifier differencing circuit 201eInput end V of the voltage boost circuit 202bConnecting;
the output terminal V of the voltage boost circuit 202cAnd a second input terminal V of the operational amplifier differencing circuit 201dConnecting;
a third input terminal V of the operational amplifier differencing circuit 201LA fourth input terminal VNAre respectively connected with an external power supply;
the output terminal V of the voltage boost circuit 202cThe output end V of the operational amplifier difference calculating circuit 201fAre respectively connected with the output end of the primary side voltage acquisition circuit 200.
Preferably, referring to fig. 4, the voltage boost circuit 202 in the embodiment of the present invention is a circuit diagram, where the voltage boost circuit 202 includes a second resistor R2, a third resistor R3, and a first operational amplifier U2;
one end of the second resistor R2 is connected to the input end of the voltage boost circuit 202, and the other end is connected to the first input end of the first operational amplifier U2;
one end of the third resistor R3 is connected with the first input end of the first operational amplifier U2, and the other end is grounded;
a second input of the first operational amplifier U2 is connected with an output of the first operational amplifier U2;
the output terminal of the first operational amplifier U2 is connected to the output terminal of the voltage boost circuit 202.
Preferably, referring to fig. 3, the circuit diagram of the operational amplifier differencing circuit 201 in the embodiment of the present invention is shown, where the operational amplifier differencing circuit 201 includes a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a seventh resistor R7, a second operational amplifier U3, a fourth capacitor C4, and a fifth capacitor C5;
one end of the fourth resistor R4 and the second input terminal V of the operational amplifier differencing circuit 201dThe other end of the first operational amplifier U3 is connected with a first input end of the second operational amplifier U3;
one end of the fifth resistor R5 and the third input terminal V of the operational amplifier differencing circuit 201LThe other end of the first operational amplifier U3 is connected with a first input end of the second operational amplifier U3;
one end of the sixth resistor R6 and the fourth input terminal V of the operational amplifier differencing circuit 201NThe other end of the second operational amplifier is connected with a second input end of the second operational amplifier U3;
one end of the seventh resistor R7 is connected to the second input end of the second operational amplifier U3, and the other end is connected to the output end of the second operational amplifier U3;
the fifth capacitor C5 is electrically connected in parallel at two ends of the seventh resistor R7;
the third input terminals of the second operational amplifier U3 and the first input terminal V of the operational amplifier differencing circuit 201 respectivelyeThe fourth capacitorA first end connection of C4; a second end of the fourth capacitor C4 is grounded;
a fourth input terminal of the second operational amplifier U3 is grounded;
the output terminal of the second operational amplifier U3 and the output terminal V of the operational amplifier differencing circuit 201fAnd (4) connecting.
It should be noted that the primary side voltage collecting circuit 200 includes an operational amplifier difference circuit 201 and a voltage boost circuit 202, and is configured to convert an ac or dc voltage of an external power supply supplied by the power quality device into a threshold voltage according to a certain ratio. In the operational amplifier differencing circuit 201, the third input terminal V of the operational amplifier differencing circuitLA fourth input terminal VNThe input voltage of (a) is an alternating current or direct current voltage for supplying power to an external power supply of the power quality device, wherein R4/R5 is R7/R6. Output terminal V of DCDC boost isolation power supply circuit 100aThe output signal VCC _ PW5V0 (output voltage 5V) supplies power to the second operational amplifier U3. since there is no negative voltage supplying the second operational amplifier U3, the second operational amplifier U3 clips the input ac voltage, thus adding the 2.5V dc voltage boost circuit 202. The voltage boost circuit 202 is a voltage follower circuit of the operational amplifier, and a voltage is provided by a 5V voltage of VCC _ PW5V0 of the DCDC boost isolation power supply circuit 100, and is divided by the second resistor R2 and the third resistor R3 to obtain a 2.5V voltage, which is input to a first input terminal (non-inverting input terminal) of the first operational amplifier U2; the second resistor R2 and the third resistor R3 are divider resistors with equal resistance. The output terminal of the first operational amplifier U2 outputs a dc boost voltage VREF of 2.5V, and the dc boost voltage VREF is input to the fourth resistor R4 of the operational amplifier differencing circuit 201 and the second interface of the level shifter circuit 300.
Preferably, the primary side voltage collecting circuit 200 may be a chip with a primary side voltage collecting function, such as a TLC2272IDR chip. Wherein, the 1 pin of the chip is the output end V of the operational amplifier difference calculating circuit 201f(output terminal of the second operational amplifier) connected to the third interface of the level shift circuit 300; the 2 pin of the chip is the second input end of a second operational amplifier U3 and passes through a sixth resistorR6 and the fourth input terminal V of the operational amplifier differencing circuit 201NConnecting; the 3 pin of the chip is the first input terminal of the second operational amplifier U3, and is connected to the third input terminal V of the operational amplifier difference circuit 201 through the fifth resistor R5LConnecting; the 4-pin of the chip is a fourth input end of a second operational amplifier U3 and is connected with the ground; the chip has a pin 5 as a first input terminal of a first operational amplifier U2, which is connected to an input terminal V of the voltage boost circuit 202 via a second resistor R2bConnecting; pin 6 of the chip is a second input end of the first operational amplifier U2, pin 7 of the chip is an output end of the first operational amplifier U2, and pin 6 is connected with pin 7; the 8-pin of the chip is the third input terminal of the second operational amplifier U3, and the first input terminal V of the operational amplifier differencing circuit 201eAnd (4) connecting.
Preferably, referring to fig. 5, the circuit diagram of the level shift circuit in the embodiment of the present invention is shown, where the level shift circuit 300 includes a threshold voltage input circuit 301, a sixth capacitor C6, an eighth resistor R8, and a level shift chip X1;
output end V of the DCDC boosting isolation power supply circuit 100cAnd a first input terminal V of the level shift circuit 300iA fourth input terminal VlConnecting;
the first interface of the level shift chip X1 and the first input terminal V of the level shift circuit 300iThe first end of the sixth capacitor C6 is connected, and the second end of the sixth capacitor C6 is grounded;
a second input terminal V of the level shift circuit 300hAnd the output end V of the voltage boost circuit 202cConnected to a third input terminal V of said level shifter circuit 300gAnd the output terminal V of the operational amplifier differencing circuit 201fConnecting;
a second input terminal V of the level shift circuit 300hA third input terminal V of the level shift circuit 300 connected to the first input terminal of the threshold voltage input circuit 301gA second input terminal of the threshold voltage input circuit 301, and a first output terminal of the threshold voltage input circuit 301 and the level shift chipA second interface connection of the X1, wherein a second output terminal of the threshold voltage input circuit 301 is connected to a third interface of the level shift chip X1;
a fourth input terminal V of the level shifter circuit 300lThe fourth interface of the level conversion chip X1 is connected;
one end of the eighth resistor R8 is connected with the fifth interface of the level shift chip X1, and the other end is grounded;
the sixth interface of the level conversion chip X1 is grounded; the seventh interface of the level shift chip X1 and the output terminal V of the level shift circuit 300jAnd (4) connecting.
Further, the threshold voltage input circuit 301 includes a seventh capacitor C7, a ninth resistor R9, and a tenth resistor R10;
a first end of the ninth resistor R9 is connected to the second input end of the threshold voltage input circuit 301, and a second end of the ninth resistor R9 is connected to the second output end of the threshold voltage input circuit 301;
one end of the tenth resistor R10 is connected with the second end of the ninth resistor R9, and the other end is grounded;
one end of the seventh capacitor C7 is connected to the first output end of the threshold voltage input circuit 301, and the other end is connected to the second output end of the threshold voltage input circuit 301.
It should be noted that the primary side voltage acquisition circuit 200 converts the external power voltage supplied by the power quality device into a threshold voltage according to a certain ratio, and the threshold voltage input circuit 301 is a circuit that inputs the threshold voltage into the level conversion chip X1. The level shift chip X1 may be an ADCMP609BRMZ2 chip, and has input pins of a second interface (Vp) and a third interface (Vn), the input pin of the second interface is the output voltage VREF of the voltage boost circuit 202, and the input pin of the third interface is the output voltage of the operational amplifier difference circuit 201. Then, when the second interface Vp is greater than the third interface Vn, the seventh interface of the output pin is at a high level, otherwise, the seventh interface of the output pin is at a low level. For example, in the embodiment, the output VREF of the 2.5V voltage boost circuit 202 is input to the second interface, the voltage of the output voltage of the operational amplifier difference calculating circuit 201 is input to the third interface, the voltage of the ninth resistor R9 and the tenth resistor R10 passes through the voltage dividing resistor, the seventh interface of the level shift circuit 300 outputs a 5V square wave having the same frequency as the supplied ac voltage when the ac voltage is supplied to the power quality device, and the seventh interface of the level shift circuit 300 outputs a low level when the dc voltage is supplied to the power quality device.
Preferably, referring to fig. 6, the circuit diagram of the optical coupling isolation circuit in the embodiment of the present invention is shown, where the optical coupling isolation circuit 400 includes an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and an optical coupler U4;
one end of the eleventh resistor R11 and the input end V of the optical coupler isolation circuit 400kThe other end of the optical coupler is connected with a first port of the optical coupler U4; the second port and the third port of the optical coupler U4 are grounded;
a fourth port of the optical coupler U4, a first end of the twelfth resistor R12, a first end of the thirteenth resistor R13 and an output end V of the optical coupler isolation circuit 400OUTConnecting; a second end of the twelfth resistor R12 is connected with a voltage power supply; a second end of the thirteenth resistor R13 is grounded.
The optocoupler U4 of the optocoupler isolation circuit 400 is a unidirectional optocoupler, the pin 1 of the input optocoupler U4 is a signal which enables an output signal INT _ PW _ DT _ AC 'of the level conversion chip X1 of the level conversion circuit 300 to pass through the eleventh resistor R11 of the current limiting resistor, and when the output signal INT _ PW _ DT _ AC' of the level conversion chip X1 is at a high level, the pin 4 of the optocoupler U4 outputs a signal INT _ PW _ DT _ AC at a low level, and otherwise, the pin is at a high level. Further, an INT _ PW _ DT _ AC signal output by the optocoupler U4 is divided by a twelfth resistor R12 and a thirteenth resistor R13 to obtain a voltage of 3.3V. Therefore, when the power quality device is supplied with alternating voltage, the INT _ PW _ DT _ AC output by the 4 pins of the optocoupler U4 of the optocoupler isolation circuit 400 is a 3.3V square wave with the same frequency as the supplied alternating voltage; when the power quality device is supplied with direct-current voltage, the output INT _ PW _ DT _ AC of the 4-pin output of the optocoupler U4 of the optocoupler isolation circuit 400 is at a high level of 3.3V.
Further, the optical coupling isolation circuit 400 output terminal VOUTAnd the processor is connected with the processor and used for judging whether the system is powered down or not. Specifically, a 4-pin output signal INT _ PW _ DT _ AC of the optocoupler U4 of the optocoupler isolation circuit 400 is connected to a GPIO pin of the power quality device processor, and whether power is supplied to the power quality device by AC or dc, the power failure is determined according to the fact that the power failure is determined when the INT _ PW _ DT _ AC signal is at a low level and the power failure of the system is not detected after a certain delay. By way of example, the delay may be 40ms when 50Hz ac is supplied to the power quality device. The electric energy quality device uses an enhanced power supply, can continuously keep running for about 2S when power supply is lost, and can store important data into a memory of the electric energy quality device in about 2S after the processor judges that the electric energy quality device is powered off.
The embodiment of the utility model provides a theory of operation is:
when the power quality device is powered off, the external power supply cannot supply power to the primary side voltage acquisition circuit 200, and the primary side voltage acquisition circuit 200 and the level conversion circuit 300 are supplied with power by the DCDC boost isolation power supply circuit 100. The primary side voltage acquisition circuit 200 converts the output 5V voltage of the DCDC boost isolation power supply circuit 100 to a boost voltage of 2.5V through the voltage boost circuit 202, and the boost voltage of 2.5V is connected to the level conversion circuit 300. In addition, the 2.5V boosted voltage is input to the operational amplifier differencing circuit 201, and is divided by the ninth resistor R9 and the tenth resistor R10 of the level shifter circuit 300, and the resultant voltage is input to the level shifter chip X1 and is compared with the 2.5V boosted voltage. At this time, since the input voltage of the second interface of the level shift chip X1 is greater than the input voltage of the third section, the output of the level shift circuit 300 is always at the high level. Furthermore, the output of level shift circuit 300 is connected through current-limiting resistance and opto-coupler U4 of opto-coupler isolation circuit 400, opto-coupler isolation circuit 400 has isolation function and has level conversion function simultaneously, convert the output high level of level shift circuit 300 into the low level, thereby the output of opto-coupler isolation circuit 400 is connected to the treater, it falls to judge the power quality device to fall the electricity along the rising edge when the treater does not detect after certain delay, the treater deposits power quality device data in the memory of power quality device in the extension time.
When the power quality device is not powered down, if the power quality device is supplied with alternating voltage, the seventh interface of the level conversion circuit 300 outputs 5V square waves with the same frequency as the alternating voltage of the power supply, and then after the output signal of the level conversion circuit 300 is input into the optical coupling isolation circuit 400 for level conversion, the output signal of the optical coupling 4 pin of the optical coupling isolation circuit 400 is divided into 3.3V square waves with the same frequency as the alternating voltage of the power supply, so that the processor judges that the power quality is not powered down. If the power quality device is supplied with direct-current voltage, the seventh interface of the level conversion circuit outputs low level, and then the output signal of the pin 4 of the optical coupler isolation circuit is 3.3V high level, so that the processor judges that the power quality is not powered down.
Compared with the prior art, the utility model discloses a power quality device power-down detection circuit, through power quality device power-down detection circuit includes DCDC boost isolation power supply circuit, primary side voltage acquisition circuit, level conversion circuit, opto-coupler isolation circuit; the input end of the DCDC boosting isolation power supply circuit is connected with a voltage power supply, and the output end of the DCDC boosting isolation power supply circuit is respectively connected with the input end of the primary side voltage acquisition circuit and the input end of the level conversion circuit; the output end of the primary side voltage acquisition circuit is connected with the input end of the level conversion circuit, the output end of the level conversion circuit is connected with the input end of the optical coupling isolation circuit, the output end of the optical coupling isolation circuit is connected with the processor, when the power quality device is powered off, the DCDC boost isolation power supply circuit isolates a system voltage power supply of the power quality device and supplies power to the primary side voltage acquisition circuit and the level conversion circuit, the primary side voltage acquisition circuit converts an external power supply supplied with power by the power quality device into a threshold voltage according to a certain proportion and transmits the threshold voltage to the level conversion circuit, the level conversion circuit adjusts and outputs a level signal according to the threshold voltage, the optical coupling isolation circuit transmits the output level signal of the level conversion circuit to the processor of the power quality device after optical coupling isolation, and the processor detects the system power off, therefore, the data of the power quality device is stored in a time delay manner, the problem that the power quality data cannot be stored in time when the power quality device in the prior art is powered down can be solved, the primary side voltage and the secondary side voltage can be isolated, the power down condition of an alternating current power supply and a direct current power supply can be detected simultaneously, and the power down detection circuit is stable and reliable.
The foregoing is a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, a plurality of improvements and decorations can be made without departing from the principle of the present invention, and these improvements and decorations are also considered as the protection scope of the present invention.
Claims (1)
1. A power failure detection circuit of an electric energy quality device is characterized by comprising a DCDC boosting isolation power supply circuit, a primary side voltage acquisition circuit, a level conversion circuit and an optical coupling isolation circuit;
the input end of the DCDC boosting isolation power supply circuit is connected with a voltage power supply, and the output end of the DCDC boosting isolation power supply circuit is respectively connected with the input end of the primary side voltage acquisition circuit and the input end of the level conversion circuit;
the output end of the primary side voltage acquisition circuit is connected with the input end of the level conversion circuit, the output end of the level conversion circuit is connected with the input end of the optical coupling isolation circuit, and the output end of the optical coupling isolation circuit is connected with the processor;
the DCDC boost isolation power supply circuit comprises a voltage input circuit, a voltage output circuit for filtering and a DCDC isolator;
the input end of the voltage input circuit is connected with the input end of the DCDC boosting isolation power supply circuit; a first output end of the voltage input circuit is connected with a first input end of the DCDC isolator, and a second output end of the voltage input circuit is connected with a second input end of the DCDC isolator; the second input end of the DCDC isolator is grounded;
a first input end of the voltage output circuit is connected with a first output end of the DCDC isolator, and a second input end of the voltage output circuit is connected with a second output end of the DCDC isolator; the output end of the voltage output circuit is connected with the second output end of the DCDC isolator and the output end of the DCDC boosting isolation power supply circuit; the first output end of the DCDC isolator is grounded;
the DCDC isolator is used for realizing the isolation conversion of a system voltage power supply from 3.3V to a voltage source from 5V; the first input end of the DCDC isolator is a Vin positive electrode interface, particularly a 3.3V voltage input end, and the second input end of the DCDC isolator is a Vin negative electrode interface and is connected with the ground; a system voltage power supply of 3.3V is input into the DCDC isolator through a voltage input circuit; the first output end and the second output end of the DCDC isolator are 5V voltage output ends, and the DCDC isolator converts a voltage power supply VCC _3V3 on the secondary side of a system of the power quality device into VCC _ PW5V0 output voltage on the primary side;
the voltage input circuit comprises a first capacitor and a second capacitor;
the first end of the first capacitor is respectively connected with the input end of the voltage input circuit and the first output end of the voltage input circuit, and the second end of the first capacitor is connected with the second output end of the voltage input circuit; the second capacitor is electrically connected to two ends of the first capacitor in parallel;
the voltage output circuit comprises a first resistor and a third capacitor;
one end of the third capacitor is connected with the first input end of the voltage output circuit, and the other end of the third capacitor is connected with the second input end of the voltage output circuit; the first resistor is electrically connected to two ends of the third capacitor in parallel;
the primary side voltage acquisition circuit comprises an operational amplifier difference circuit and a voltage lifting circuit;
the input end of the primary side voltage acquisition circuit is respectively connected with the first input end of the operational amplifier difference circuit and the input end of the voltage lifting circuit;
the output end of the voltage lifting circuit is connected with the second input end of the operational amplifier difference calculating circuit;
a third input end and a fourth input end of the operational amplifier difference calculating circuit are respectively connected with an external power supply;
the output end of the voltage lifting circuit and the output end of the operational amplifier difference circuit are respectively connected with the output end of the primary side voltage acquisition circuit;
the voltage lifting circuit comprises a second resistor, a third resistor and a first operational amplifier;
one end of the second resistor is connected with the input end of the voltage lifting circuit, and the other end of the second resistor is connected with the first input end of the first operational amplifier;
one end of the third resistor is connected with the first input end of the first operational amplifier, and the other end of the third resistor is grounded;
the second input end of the first operational amplifier is connected with the output end of the first operational amplifier;
the output end of the first operational amplifier is connected with the output end of the voltage lifting circuit;
the operational amplifier difference calculating circuit comprises a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a second operational amplifier, a fourth capacitor and a fifth capacitor;
one end of the fourth resistor is connected with the second input end of the operational amplifier difference calculating circuit, and the other end of the fourth resistor is connected with the first input end of the second operational amplifier;
one end of the fifth resistor is connected with the third input end of the operational amplifier difference calculating circuit, and the other end of the fifth resistor is connected with the first input end of the second operational amplifier;
one end of the sixth resistor is connected with the fourth input end of the operational amplifier difference calculating circuit, and the other end of the sixth resistor is connected with the second input end of the second operational amplifier;
one end of the seventh resistor is connected with the second input end of the second operational amplifier, and the other end of the seventh resistor is connected with the output end of the second operational amplifier;
the fifth capacitor is electrically connected to two ends of the seventh resistor in parallel;
a third input end of the second operational amplifier is respectively connected with a first input end of the operational amplifier difference calculating circuit and a first end of the fourth capacitor; a second end of the fourth capacitor is grounded;
a fourth input end of the second operational amplifier is grounded;
the output end of the second operational amplifier is connected with the output end of the operational amplifier difference calculating circuit;
the level conversion circuit comprises a threshold voltage input circuit, a sixth capacitor, an eighth resistor and a level conversion chip;
the output end of the DCDC boosting isolation power supply circuit is connected with the first input end and the fourth input end of the level switching circuit;
a first interface of the level conversion chip is connected with a first input end of the level conversion circuit and a first end of a sixth capacitor, and a second end of the sixth capacitor is grounded;
a second input end of the level conversion circuit is connected with an output end of the voltage lifting circuit, and a third input end of the level conversion circuit is connected with an output end of the operational amplifier difference calculating circuit;
a second input end of the level conversion circuit is connected with a first input end of the threshold voltage input circuit, a third input end of the level conversion circuit is connected with a second input end of the threshold voltage input circuit, a first output end of the threshold voltage input circuit is connected with a second interface of the level conversion chip, and a second output end of the threshold voltage input circuit is connected with a third interface of the level conversion chip;
a fourth input end of the level conversion circuit is connected with a fourth interface of the level conversion chip;
one end of the eighth resistor is connected with the fifth interface of the level conversion chip, and the other end of the eighth resistor is grounded;
a sixth interface of the level conversion chip is grounded; a seventh interface of the level conversion chip is connected with the output end of the level conversion circuit;
the threshold voltage input circuit comprises a seventh capacitor, a ninth resistor and a tenth resistor;
a first end of the ninth resistor is connected with the second input end of the threshold voltage input circuit, and a second end of the ninth resistor is connected with the second output end of the threshold voltage input circuit;
one end of the tenth resistor is connected with the second end of the ninth resistor, and the other end of the tenth resistor is grounded;
one end of the seventh capacitor is connected with the first output end of the threshold voltage input circuit, and the other end of the seventh capacitor is connected with the second output end of the threshold voltage input circuit;
the optical coupler isolation circuit comprises an eleventh resistor, a twelfth resistor, a thirteenth resistor and an optical coupler;
one end of the eleventh resistor is connected with the input end of the optical coupler isolation circuit, and the other end of the eleventh resistor is connected with the first port of the optical coupler; the second port and the third port of the optical coupler are grounded;
a fourth port of the optical coupler is connected with a first end of the twelfth resistor, a first end of the thirteenth resistor and an output end of the optical coupler isolation circuit; a second end of the twelfth resistor is connected with a voltage power supply; a second end of the thirteenth resistor is grounded.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920624495.3U CN211453891U (en) | 2019-04-30 | 2019-04-30 | Power failure detection circuit of power quality device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201920624495.3U CN211453891U (en) | 2019-04-30 | 2019-04-30 | Power failure detection circuit of power quality device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211453891U true CN211453891U (en) | 2020-09-08 |
Family
ID=72317360
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201920624495.3U Active CN211453891U (en) | 2019-04-30 | 2019-04-30 | Power failure detection circuit of power quality device |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN211453891U (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114115181A (en) * | 2021-11-12 | 2022-03-01 | 天津航空机电有限公司 | Voltage acquisition circuit of solid-state power controller |
-
2019
- 2019-04-30 CN CN201920624495.3U patent/CN211453891U/en active Active
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114115181A (en) * | 2021-11-12 | 2022-03-01 | 天津航空机电有限公司 | Voltage acquisition circuit of solid-state power controller |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN206096314U (en) | Power failure detection system and electric meter system | |
| CN105572523A (en) | AC detection circuit | |
| CN103580272A (en) | Time-delay circuit for outage of power source | |
| CN101950820A (en) | Static zero consumption energy-saving charging device | |
| CN211453891U (en) | Power failure detection circuit of power quality device | |
| CN209224953U (en) | High-voltage interlocking detection device and vehicle | |
| CN202488204U (en) | Main-auxiliary power supply automatic switching circuit used for state grid three-phase intelligent electric energy meter | |
| CN110601569A (en) | Current transformer gets electric circuit | |
| CN204008785U (en) | Measurement loop fault monitoring system | |
| CN209419207U (en) | Dc source power output limits protection circuit | |
| CN213122225U (en) | Power failure detection circuit | |
| CN204287447U (en) | A kind of alternating current-direct current input detecting circuit | |
| CN207502604U (en) | A kind of electric energy meter | |
| CN107968643A (en) | A kind of DC load singly-bound touch control on-off circuit | |
| CN204649888U (en) | A kind of novel lan device electrical interface identification circuit | |
| CN210629083U (en) | Electric leakage protection device and electric equipment | |
| CN211266785U (en) | Current transformer power taking circuit | |
| CN211318588U (en) | Intelligent electric energy meter with low-frequency load shedding function | |
| CN209282906U (en) | Power circuit and electrical equipment | |
| CN207263840U (en) | The power-fail detection circuit of power quality device | |
| CN208479488U (en) | A kind of Switching Power Supply with power down self-locking protective circuit | |
| CN207283400U (en) | A kind of on/off circuit and electronic product | |
| CN101478153B (en) | Pilot type control circuit | |
| CN110890779A (en) | Incoming call self-starting circuit of lithium battery management system and lithium battery management system | |
| CN206819200U (en) | A kind of fictitious load control circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |