CN216904693U - Circuit for detecting voltage sag - Google Patents
Circuit for detecting voltage sag Download PDFInfo
- Publication number
- CN216904693U CN216904693U CN202123399196.0U CN202123399196U CN216904693U CN 216904693 U CN216904693 U CN 216904693U CN 202123399196 U CN202123399196 U CN 202123399196U CN 216904693 U CN216904693 U CN 216904693U
- Authority
- CN
- China
- Prior art keywords
- circuit
- phase
- rectifying
- resistor
- diode
- 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
Images
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y04—INFORMATION OR COMMUNICATION TECHNOLOGIES HAVING AN IMPACT ON OTHER TECHNOLOGY AREAS
- Y04S—SYSTEMS INTEGRATING TECHNOLOGIES RELATED TO POWER NETWORK OPERATION, COMMUNICATION OR INFORMATION TECHNOLOGIES FOR IMPROVING THE ELECTRICAL POWER GENERATION, TRANSMISSION, DISTRIBUTION, MANAGEMENT OR USAGE, i.e. SMART GRIDS
- Y04S10/00—Systems supporting electrical power generation, transmission or distribution
- Y04S10/50—Systems or methods supporting the power network operation or management, involving a certain degree of interaction with the load-side end user applications
- Y04S10/52—Outage or fault management, e.g. fault detection or location
Abstract
The utility model discloses a circuit for detecting voltage sag, comprising: the power supply control circuit comprises a detection power grid RST, a rectifying circuit, a current-limiting resistor circuit, a critical turn-off Zener diode D4, a photoelectric coupler U1, a fourth resistor R4 and a power supply; the rectification circuit is connected with a detection power grid RST; one end of the current-limiting resistance circuit is connected with one end of the rectifying circuit, and the other end of the current-limiting resistance circuit is connected with a critical turn-off Zener diode D4; the other end of the critical turn-off zener diode D4 is connected with pin 1 of the photoelectric coupler U1; pin 2 of the photoelectric coupler U1 is connected with the other end of the rectifying circuit; pin 3 of the photocoupler U1 is grounded; pin 4 of the photoelectric coupler U1 is connected with a fourth resistor R4; the other end of the fourth resistor R4 is connected to a power supply. The utility model has simple structure, quick response to the voltage sag of the circuit and excellent accuracy on the premise of facing auxiliary power grid distortion, harmonic wave and inter-harmonic interference.
Description
Technical Field
The utility model relates to the technical field of voltage sag, in particular to a circuit for detecting voltage sag.
Background
In recent years, with the deep development of various industrial industries, the influence of the electric energy quality on the safe and stable operation of equipment is increasingly prominent, so that the monitoring and the timely early warning of the electric energy quality become an important part in engineering application.
The voltage sag is a problem that the power grid has a high probability, when the power grid has the voltage sag, the voltage sag cannot be quickly responded, so that the method has relatively great harmfulness, for example, in the application of a numerical control machine tool, tripping protection of servo driving equipment and PWM rectifier equipment, damage of a file of a computer system without a UPS (uninterrupted power supply), uncontrolled power failure of a servo shaft in work, damage of a machined blank, a cutter and the like are caused.
Disclosure of Invention
The utility model provides a circuit for detecting voltage sag, which aims to solve the technical problem that the circuit cannot respond quickly when the voltage sag of a power grid occurs.
In order to achieve the purpose, the technical scheme of the utility model is as follows:
a circuit for detecting a voltage sag, comprising: the power supply control circuit comprises a detection power grid RST, a rectifying circuit, a current-limiting resistor circuit, a critical turn-off Zener diode D4, a photoelectric coupler U1, a fourth resistor R4 and a power supply;
the rectification circuit is connected with a detection power grid RST; the detection power grid comprises an R-phase detection line, an S-phase detection line and a T-phase detection line;
one end of the current-limiting resistance circuit is connected with one end of the rectifying circuit, and the other end of the current-limiting resistance circuit is connected with the critical turn-off Zener diode D4;
the other end of the critical turn-off Zener diode D4 is connected with a pin 1 of the photoelectric coupler U1; pin 2 of the photoelectric coupler U1 is connected with the other end of the rectifying circuit; pin 3 of the photoelectric coupler U1 is grounded; pin 4 of the photoelectric coupler U1 is connected with the fourth resistor R4; the other end of the fourth resistor R4 is connected with a power supply.
Further, the rectification circuit comprises an R-phase rectification circuit, an S-phase rectification circuit and a T-phase rectification circuit;
the R-phase rectifying circuit is connected with the R-phase detection line; the S-phase rectifying circuit is connected with the S-phase detection line; the T-phase rectifying circuit is connected with the T-phase detection line;
the R-phase rectifying circuit, the S-phase rectifying circuit and the T-phase rectifying circuit are connected in parallel.
Further, the R-phase rectifying circuit includes a first rectifying diode D1 and a fifth rectifying diode D5; the first rectifying diode D1 and the fifth rectifying diode D5 are connected in series; the R phase detection line is connected to the junction of the first rectifier diode D1 and a fifth rectifier diode D5;
the S-phase rectifying circuit comprises a second rectifying diode D2 and a sixth rectifying diode D6; the second rectifying diode D2 and a sixth rectifying diode D6 are connected in series; the S-phase detection line is connected to the junction of the second rectifier diode D2 and a sixth rectifier diode D6;
the T-phase rectifying circuit comprises a third rectifying diode D3 and a seventh rectifying diode D7; the third rectifying diode D3 and the seventh rectifying diode D7 are connected in series; the T-phase detection line is connected to a junction of the third rectifier diode D3 and the seventh rectifier diode D7.
Furthermore, the current-limiting resistance circuit comprises a plurality of current-limiting resistance branches;
one end of the current-limiting resistor branch circuit is connected with one end of the R-phase rectifying circuit, and the other end of the current-limiting resistor branch circuit is connected with the critical turn-off Zener diode D4;
and a plurality of current-limiting resistor branches are connected in series.
Further, the current-limiting resistance branch comprises a first resistor R1 and a fifth resistor R5;
the first resistor R1 and the fifth resistor R5 are connected in parallel;
one end of the first resistor R1 is connected with the R-phase rectifying circuit, and the other end is connected with the critical turn-off Zener diode D4.
Further, an eighth resistor R8 is also included;
one end of the eighth resistor R8 is connected with pin 1 of the photoelectric coupler U1; the other end is connected with pin 2 of the photoelectric coupler U1.
Has the advantages that: the circuit for detecting the voltage sag has a simple structure, is quick in response to the voltage sag of the circuit, and still has excellent accuracy on the premise of facing auxiliary power grid distortion, harmonic waves and inter-harmonic interference.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the description of the embodiments or the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.
FIG. 1 is a block diagram of the hardware circuit for detecting voltage sags of the present invention;
FIG. 2 is a schematic diagram of rectification of a rectifier circuit according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The embodiment provides a circuit for detecting voltage sag, which is characterized by comprising: the power supply control circuit comprises a detection power grid RST, a rectifying circuit, a current-limiting resistor circuit, a critical turn-off Zener diode D4, a photoelectric coupler U1, a fourth resistor R4 and a power supply;
the rectification circuit is connected with a detection power grid RST; the detection power grid comprises an R-phase detection line, an S-phase detection line and a T-phase detection line;
specifically, the rectification circuit comprises an R-phase rectification circuit, an S-phase rectification circuit and a T-phase rectification circuit; the R-phase rectifying circuit is connected with the R-phase detection line; the S-phase rectifying circuit is connected with the S-phase detection line; the T-phase rectifying circuit is connected with the T-phase detection line; the R-phase rectifying circuit, the S-phase rectifying circuit and the T-phase rectifying circuit are connected in parallel to form a three-phase bridge rectifying circuit;
preferably, the R-phase rectification circuit includes a first rectification diode D1 and a fifth rectification diode D5; the first rectifying diode D1 and the fifth rectifying diode D5 are connected in series; the R phase detection line is connected to the junction of the first rectifier diode D1 and a fifth rectifier diode D5; the S-phase rectifying circuit comprises a second rectifying diode D2 and a sixth rectifying diode D6; the second rectifying diode D2 and a sixth rectifying diode D6 are connected in series; the S-phase detection line is connected to the junction of the second rectifier diode D2 and a sixth rectifier diode D6; the T-phase rectifying circuit comprises a third rectifying diode D3 and a seventh rectifying diode D7; the third rectifying diode D3 and the seventh rectifying diode D7 are connected in series; the T-phase detection line is connected to a junction of the third rectifier diode D3 and the seventh rectifier diode D7.
The R-phase rectification circuit, the S-phase rectification circuit and the T-phase rectification circuit form a three-phase bridge rectification circuit; the three-phase bridge rectifier circuit comprises 3 groups of 6 rectifier diodes in total, and no energy storage element is added, so that rectified pulsating direct current can quickly follow the voltage sag process of a three-phase power grid, and the three-phase voltage sag is reflected in the reduction of the amplitude of direct current pulsating voltage after passing through the three-phase bridge rectifier circuit.
One end of the current-limiting resistance circuit is connected with one end of the rectifying circuit, and the other end of the current-limiting resistance circuit is connected with the critical turn-off Zener diode D4;
specifically, the current-limiting resistance circuit comprises a plurality of current-limiting resistance branches; one end of the current-limiting resistor branch is connected with the common end P of the R-phase rectifying circuit, the S-phase rectifying circuit and the T-phase rectifying circuit, and the other end of the current-limiting resistor branch is connected with the critical turn-off Zener diode D4; and a plurality of current-limiting resistor branches are connected in series.
Preferably, the current-limiting resistance branch comprises a first resistor R1 and a fifth resistor R5; the first resistor R1 and the fifth resistor R5 are connected in parallel; one end of the first resistor R1 is connected with the R-phase rectifying circuit, and the other end is connected with the critical turn-off Zener diode D4.
The current-limiting resistor circuit of this embodiment is 6 resistance combinations, can control resistance surface temperature rise below the rated operating temperature of resistance, can guarantee resistance life, ensures the circuit steady operation of whole detection voltage sag. In this embodiment, the current-limiting resistor circuit composed of 6 resistors controls the temperature rise of the resistor surface to be less than 40 degrees by increasing the total heat dissipation surface area of the current-limiting resistor circuit.
The other end of the critical turn-off Zener diode D4 is connected with a pin 1 of the photoelectric coupler U1; pin 2 of the photoelectric coupler U1 is connected with the other end of the rectifying circuit; pin 3 of the photoelectric coupler U1 is grounded; pin 4 of the optoelectronic coupler U1 is connected with the fourth resistor R4; the other end of the fourth resistor R4 is connected with a power supply.
Specifically, the critical turn-off zener diode D4 in this embodiment is a critical turn-off zener diode with a turn-on threshold of 82V, and is used to turn off the three-phase bridge rectifier circuit quickly when the output voltage is lower than 82V, so as to accelerate the detection process. The photoelectric coupler can isolate the rectifying circuit, the current-limiting resistance circuit and the component to be controlled, and can protect the component to be controlled. The pull-up resistor, i.e., the fourth resistor R4, is a common connection method of an open-circuit output mode of a collector of a photoelectric coupler. Its resistance is 10K ohms.
Specifically, the circuit for detecting a voltage sag of the present embodiment further includes an eighth resistor R8; one end of the eighth resistor R8 is connected with pin 1 of the photoelectric coupler U1; the other end is connected with pin 2 of the photoelectric coupler U1. The eighth resistor R8 can accelerate the turn-off when the critical turn-off zener diode D4 turns off. Its resistance is 10K ohms.
Specifically, in this embodiment, when a voltage sag of the three-phase power grid occurs, the amplitude of the dc voltage passing through the three-phase bridge rectifier circuit decreases, and before the amplitude of the dc voltage decreases to 82V, current flows through the light emitting diode at the input side of the photoelectric coupler, so that the output does not jump. Then the amplitude of the direct current voltage is reduced to be lower than 82V, the critical turn-off Zener diode is turned off, no current flows through the light emitting diode on the input side of the photoelectric coupler, and the output jumps.
The results of the voltage sag detection circuit for this example are given according to the IEC reference test standard as follows: the test equipment used Chroma 61830:
| |
|
Class 3/Level 3 | Class 4/Level4 | |
| IEC61000-4-27 | test without cost | Not giving an alarm | Not giving an alarm | Not giving an alarm |
| IEC61000-4-13 | Not giving an alarm | Not giving an alarm | Not giving an alarm | Test without cost |
| IEC61000-4-14 | Test without cost | Not giving an alarm | Not giving an alarm | Test without cost |
| IEC61000-4-28 | Test without cost | Not giving an alarm | Not giving an alarm | Not giving an alarm |
From the table above, it can be seen that the circuit for detecting voltage sag of the power grid anomaly embodiment except for voltage sag does not trigger an alarm, and the output signal jumps, i.e., the voltage sag, without additional efforts of secondary judgment.
Specifically, in one embodiment of the present invention, the rated line voltage Uc of the three-phase grid is 380Vrms, the dc ripple value is ignored after passing through the bridge rectifier circuit, and the maximum value is 540V. The total resistance R of the current-limiting resistor circuit of this embodiment is 300K ohms, and the total heating power PR is 0.69W, and 6 2512 package resistors can control the surface temperature rise of a single resistor at 20 degrees centigrade and the ambient temperature of the resistor not to exceed 40 degrees centigrade. The operating voltage threshold Ud of the critical turn-off zener diode D4 is 82V. The on-state voltage drop Uvf of the light emitting diode at the input side of the photoelectric coupler U1 is 1.17V, the current transfer ratio CTR is 200-400%, and the influence of the parallel resistor R8 at the input side of the photoelectric coupler U1 on the main circuit current is ignored. The withstand voltage of each diode of the rectifying circuit is 1000V; the parameters selected were calculated as follows:
r8 is the photocoupler U1 turn-off accelerating resistor with the resistance of 10K ohm.
Specifically, in the present embodiment,
rated main circuit current at input side of photoelectric coupler U1:
rated current-limiting resistance heating power, i.e. maximum heating power:
PR＝I2·R＝1.522·300·10-3＝0.69W
rated critical turn-off zener diode heating power, i.e., maximum heating power:
PD＝I·U＝1.52·82·10-3＝0.12W
the current of the output side of the photoelectric coupler is calculated according to the minimum current transfer ratio CTR which is 200 percent:
IS-100％＝I·200％＝3mA
according to the 3.3V system power supply, the jump-type pull-up resistor R is not output under the rated working statepullupThe resistance is at least 1.1K ohms.
When the voltage of the power grid fluctuates, the system should not output jump, and when the power grid is temporarily reduced to 40% of the rated value, the system does not give an alarm.
The parameter calculation method at this time is as follows:
rated main circuit current at input side of photoelectric coupler:
the current of the output side of the photoelectric coupler is calculated according to the minimum current transfer ratio CTR which is 200 percent:
IS-40％＝I·200％＝0.88mA
according to the 3.3V system power supply, the jump-type pull-up resistor R is not output under the rated working statepullup-40％Resistance of at least 3.75K ohms:
from the above calculations it can be found that:
when the parameters are selected on the voltage sag input side, the pull-up resistance on the output side is at least 3.75K ohms, and the pull-up resistance of 10K ohms is selected in consideration of the error of hardware parameters and a lower alarm threshold, so that the alarm threshold can be set to be closer to about 58V of line voltage, namely the direct-current voltage behind the rectifier bridge is about 82V.
The circuit for detecting the voltage sag has a simple structure, is quick in response to the voltage sag of the circuit, and has excellent accuracy on the premise of facing auxiliary power grid distortion, harmonic waves and inter-harmonic interference because the system does not give an alarm when the power grid sag is 40% of a rated value, and other interference cannot act on the circuit when the power grid sag is not reduced to a threshold value for starting the circuit.
Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the utility model has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.
Claims (6)
1. A circuit for detecting a voltage sag, comprising: the power supply control circuit comprises a detection power grid RST, a rectifying circuit, a current-limiting resistor circuit, a critical turn-off Zener diode D4, a photoelectric coupler U1, a fourth resistor R4 and a power supply;
the rectification circuit is connected with a detection power grid RST; the detection power grid comprises an R-phase detection line, an S-phase detection line and a T-phase detection line;
one end of the current-limiting resistance circuit is connected with one end of the rectifying circuit, and the other end of the current-limiting resistance circuit is connected with the critical turn-off Zener diode D4;
the other end of the critical turn-off Zener diode D4 is connected with pin 1 of the photoelectric coupler U1; pin 2 of the photoelectric coupler U1 is connected with the other end of the rectifying circuit; pin 3 of the photoelectric coupler U1 is grounded; pin 4 of the photoelectric coupler U1 is connected with the fourth resistor R4; the other end of the fourth resistor R4 is connected with a power supply.
2. The circuit for detecting a voltage sag of claim 1, wherein the rectification circuit comprises an R-phase rectification circuit, an S-phase rectification circuit, and a T-phase rectification circuit;
the R-phase rectifying circuit is connected with the R-phase detection line; the S-phase rectifying circuit is connected with the S-phase detection line; the T-phase rectifying circuit is connected with the T-phase detection line;
the R-phase rectifying circuit, the S-phase rectifying circuit and the T-phase rectifying circuit are connected in parallel.
3. The circuit for detecting a voltage sag of claim 2,
the R-phase rectifying circuit comprises a first rectifying diode D1 and a fifth rectifying diode D5; the first rectifying diode D1 and the fifth rectifying diode D5 are connected in series; the R phase detection line is connected to the junction of the first rectifier diode D1 and a fifth rectifier diode D5;
the S-phase rectifying circuit comprises a second rectifying diode D2 and a sixth rectifying diode D6; the second rectifying diode D2 and a sixth rectifying diode D6 are connected in series; the S-phase detection line is connected to the junction of the second rectifier diode D2 and a sixth rectifier diode D6;
the T-phase rectifying circuit comprises a third rectifying diode D3 and a seventh rectifying diode D7; the third rectifying diode D3 and the seventh rectifying diode D7 are connected in series; the T-phase detection line is connected to a junction of the third rectifier diode D3 and the seventh rectifier diode D7.
4. The circuit of claim 1, wherein the current limiting resistor circuit comprises a plurality of current limiting resistor branches;
one end of the current-limiting resistor branch circuit is connected with one end of the R-phase rectifying circuit, and the other end of the current-limiting resistor branch circuit is connected with the critical turn-off Zener diode D4;
and a plurality of current-limiting resistor branches are connected in series.
5. A circuit for detecting a voltage sag according to claim 4,
the current-limiting resistance branch comprises a first resistor R1 and a fifth resistor R5;
the first resistor R1 and the fifth resistor R5 are connected in parallel;
one end of the first resistor R1 is connected with the R-phase rectifying circuit, and the other end is connected with the critical turn-off Zener diode D4.
6. The circuit for detecting a voltage sag of claim 1, further comprising an eighth resistor R8;
one end of the eighth resistor R8 is connected with pin 1 of the photoelectric coupler U1; the other end is connected with pin 2 of the photoelectric coupler U1.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123399196.0U CN216904693U (en) | 2021-12-30 | 2021-12-30 | Circuit for detecting voltage sag |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123399196.0U CN216904693U (en) | 2021-12-30 | 2021-12-30 | Circuit for detecting voltage sag |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN216904693U true CN216904693U (en) | 2022-07-05 |
Family
ID=82210623
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123399196.0U Active CN216904693U (en) | 2021-12-30 | 2021-12-30 | Circuit for detecting voltage sag |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN216904693U (en) |
-
2021
- 2021-12-30 CN CN202123399196.0U patent/CN216904693U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8422249B2 (en) | Apparatus for a microinverter particularly suited for use in solar power installations | |
| CN102638177B (en) | Two-way four-quadrant frequency converter | |
| CN106026702B (en) | A kind of high power DC plasma electrical source | |
| CN215728707U (en) | Three-phase power supply phase loss detection circuit and motor controller of BLDC motor | |
| CN108718152A (en) | Interleaved PFC control circuit and motor-drive circuit | |
| US11418023B2 (en) | Current protection circuit and method for high voltage system | |
| CN104659787A (en) | Method and system for aging constant current power supply and detection system | |
| CN216904693U (en) | Circuit for detecting voltage sag | |
| CN101064480B (en) | AC power source converting apparatus and method | |
| CN112398171A (en) | Photovoltaic system, control method thereof and air conditioning system | |
| CN114337324A (en) | Circuit for detecting voltage sag | |
| CN204465001U (en) | The system that a kind of constant-current supply is aging and detection system | |
| CN210380651U (en) | Power supply protection circuit and alternating current-direct current power supply conversion circuit | |
| CN105896563A (en) | Zero-crossing trigger control circuit for anti-parallel thyristor split-phase switched capacitor | |
| CN205754028U (en) | A kind of high power DC plasma electrical source | |
| CN220985649U (en) | Novel synchronous signal acquisition circuit of thyristor | |
| CN211603358U (en) | Controllable open-phase detection circuit | |
| CN109613409B (en) | Wind power converter insulation detection circuit and method and wind power converter | |
| CN217935067U (en) | Over-voltage and under-voltage protection circuit and three-phase self-recovery over-voltage and under-voltage protector | |
| CN217159542U (en) | Common-mode surge voltage impact resistance circuit of air conditioner variable frequency controller | |
| CN212627300U (en) | Multi-power-supply automatic switching device | |
| CN210982598U (en) | High-voltage load monitoring circuit based on current detection | |
| CN217942164U (en) | Fault protection circuit of high-frequency welding machine | |
| CN109768712B (en) | Reactor shunt circuit and PWM energy feedback unit | |
| CN213637057U (en) | Silicon controlled rectifier load short-circuit protection circuit |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |