CN211741424U - Cascaded converter unit input phase loss detection circuit - Google Patents
Cascaded converter unit input phase loss detection circuit Download PDFInfo
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- CN211741424U CN211741424U CN201922193771.8U CN201922193771U CN211741424U CN 211741424 U CN211741424 U CN 211741424U CN 201922193771 U CN201922193771 U CN 201922193771U CN 211741424 U CN211741424 U CN 211741424U
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Abstract
The utility model discloses a cascaded type converter unit input lacks looks detection circuitry, include: the circuit comprises a voltage division circuit, a rectifying circuit, an optical coupling circuit and a control circuit; the voltage division circuit is used for connecting a power unit of the converter unit, dividing the voltage of each phase line of the three-phase power supply and then introducing the divided voltage into the rectification circuit; the rectifying circuit rectifies a three-phase power supply into a direct current and inputs the direct current into the optical coupling circuit; the optocoupler circuit comprises a voltage stabilizing diode, a protection diode and a photoelectric coupler, wherein the cathode of the voltage stabilizing diode is connected with the positive electrode of direct current, the anode of the voltage stabilizing diode is connected with the positive electrode of the primary side of the photoelectric coupler and the cathode of the protection diode, and the negative electrode of the primary side of the photoelectric coupler and the anode of the protection diode are connected with the negative electrode of the direct current; the control circuit is connected with the secondary side of the photoelectric coupler. The utility model provides a detection circuitry simple structure, the security is high, and the reaction is sensitive, can detect out fast whether three-phase electricity lacks the looks.
Description
Technical Field
The utility model relates to a circuit detection technical field, in particular to cascaded converter unit input lacks looks detection circuit.
Background
The rectification and inversion of the power are realized by the cascade type converter in a mode of cascading module units, and the stable and reliable power supply of the module units is the basis for the normal operation of the whole cascade type converter. When the three-phase power input is in the conditions of phase loss, undervoltage and the like, the three-phase load is changed into a two-phase load, so that the equipment can not work normally easily, and when the phase loss occurs, the current flowing through the equipment is increased, so that the transformer and the equipment are easily burnt.
SUMMERY OF THE UTILITY MODEL
In view of the above technical problem, the present invention provides a coupled converter unit input open-phase detection circuit to solve or at least partially solve the above problems.
In order to achieve the above purpose, the utility model adopts the following technical scheme:
the application discloses cascaded type converter unit input lacks looks detection circuit includes: voltage divider circuit, rectifier circuit, opto-coupler circuit and control circuit.
The voltage division circuit is used for connecting the power unit of the converter unit, dividing the voltage of each phase line of the three-phase power supply and then introducing the divided voltage into the rectification circuit.
The rectifying circuit rectifies the three-phase power supply into a direct current and inputs the direct current to the optical coupling circuit.
The optocoupler circuit comprises a voltage stabilizing diode, a protection diode and a photoelectric coupler, wherein the cathode of the voltage stabilizing diode is connected with the positive electrode of the direct current, the anode of the voltage stabilizing diode is connected with the positive electrode of the primary side of the photoelectric coupler and the cathode of the protection diode, and the negative electrode of the primary side of the photoelectric coupler and the anode of the protection diode are connected with the negative electrode of the direct current.
The control circuit is connected with the secondary side of the photoelectric coupler.
Further, the optical coupling circuit further comprises a pull-up resistor; the positive electrode of the secondary side of the photoelectric coupler is connected with a power supply through the pull-up resistor, the negative electrode of the secondary side of the photoelectric coupler is grounded, and the control circuit is connected with the positive electrode of the secondary side of the photoelectric coupler.
Further, the voltage stabilizing diode is a 1N4742 type voltage stabilizing diode.
Further, the photoelectric coupler is a PC817 linear photoelectric coupler.
Further, the voltage division circuit comprises a first resistor, a second resistor and a third resistor; the front ends of the first resistor, the second resistor and the third resistor are respectively connected with one phase line of a three-phase power supply.
The rectifying circuit comprises a first diode, a second diode, a third diode, a fourth diode, a fifth diode and a sixth diode; the anode of the first diode and the cathode of the second diode are connected with the rear end of the first resistor, the anode of the third diode and the cathode of the fourth diode are connected with the rear end of the second resistor, the anode of the fifth diode and the cathode of the sixth diode are connected with the rear end of the third resistor, the cathodes of the first diode, the third diode and the fifth diode are connected, and the anodes of the second diode, the fourth diode and the sixth diode are connected.
Furthermore, the first resistor, the second resistor and the third resistor are respectively formed by connecting a plurality of resistors in series.
Furthermore, a filter capacitor is connected between the direct current positive electrode and the direct current negative electrode of the rectifying circuit.
Further, the filter capacitor is a 10nF ceramic capacitor.
Further, the control circuit comprises a microprocessor, and a state indicating device and a trip switch protection device which are connected with the microprocessor.
Further, the microprocessor is a CPLD.
To sum up, the beneficial effects of the utility model are that:
the utility model discloses a set up bleeder circuit, reduce the electric current, play the effect of protection circuit, bleeder circuit can also share voltage simultaneously, reduces the partial pressure on the opto-coupler circuit, improves the security and the stability of circuit; through the design of the rectification circuit, the optocoupler circuit and the control circuit, whether the three-phase voltage is normal or not can be judged quickly and effectively, and if the phase loss or the undervoltage occurs, the control circuit can act quickly, so that the equipment is protected effectively; the utility model discloses circuit structure is simple, and sensitivity is high, and the security is good.
Drawings
Fig. 1 is a schematic diagram of a connection structure of a coupled converter unit input open-phase detection circuit according to an embodiment of the present invention;
fig. 2 is a schematic circuit diagram of a coupled converter unit input open-phase detection circuit according to an embodiment of the present invention.
Detailed Description
Exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present application are shown in the drawings, it should be understood that the present application may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.
Fig. 1 is a schematic diagram of a connection structure of a coupled converter unit input open-phase detection circuit according to an embodiment of the present invention; fig. 2 is a schematic circuit diagram of a coupled converter unit input open-phase detection circuit according to an embodiment of the present invention. As shown in fig. 1 to fig. 2, an embodiment of the present application discloses a cascaded converter unit input open-phase detection circuit, including: voltage divider circuit, rectifier circuit, opto-coupler circuit and control circuit.
The voltage division circuit is used for connecting the power unit of the converter unit, and introducing each phase line of the three-phase power supply into the rectification circuit after voltage division. Through bleeder circuit, can effectual reduction electric current, make the electric current restriction in safe range, and then improve operating personnel's security. The three-phase alternating current is rectified by the rectifying circuit to obtain direct current with pulsating voltage. In this embodiment, when the three-phase power is normal, the ripple voltage value is always equal to the sum of the reverse breakdown voltage value of the zener diode D8 and the conduction voltage drop of the input diode of the photoelectric coupler OP 1; when the three-phase power is in phase loss or under-voltage, the pulse voltage value is periodically or continuously lower than the reverse breakdown voltage value of the voltage stabilizing diode D8. When the phase is lost, the pulsating direct current voltage is periodically lower than the reverse breakdown voltage of the voltage stabilizing diode D8, so that the photoelectric coupler OP1 is periodically turned off, and at the moment, the photoelectric coupler circuit outputs a periodic high level; when the voltage is undervoltage, the pulsating direct current voltage is always lower than the reverse breakdown voltage of the voltage stabilizing diode D8, the photoelectric coupler OP1 is continuously in an off state, and the optical coupler circuit outputs continuous high level.
Rectifier circuit inputs opto-coupler circuit after becoming direct current with three phase power rectification, and corresponding reaction is made according to the direct current voltage's of input circumstances to opto-coupler circuit, and in the embodiment that this application figure 2 shows, when three-phase voltage is normal, opto-coupler circuit output continuous low level, when three-phase voltage lack of phase or under-voltage, opto-coupler circuit output periodic high level or continuous high level.
As shown in fig. 2, the optocoupler circuit includes a zener diode D8, a protection diode D7, and a photocoupler OP1, a cathode of the zener diode D8 is connected to a dc positive electrode, an anode of the zener diode D8 is connected to a primary positive electrode of the photocoupler OP1 and a cathode of the protection diode D7, and a primary negative electrode of the photocoupler OP1 and an anode of the protection diode D7 are connected to a dc negative electrode. The voltage stabilizing diode D8 plays a role in stabilizing voltage, and the protection diode D7 plays a role in protecting the optocoupler circuit.
The control circuit is connected to the secondary side of the opto-coupler OP 1.
In one embodiment, the optocoupler circuit further includes a pull-up resistor R4; the positive electrode of the secondary side of the photocoupler OP1 is connected with a power supply VCC through a pull-up resistor R4, and the power supply VCC is a high level, such as 5V, 3.3V and the like, or determined according to requirements. The negative electrode of the secondary side of the photoelectric coupler OP1 is grounded, and the control circuit is connected with the positive electrode of the secondary side of the photoelectric coupler OP 1. When the three-phase voltage is normal, the secondary positive electrode of the photoelectric coupler OP1 and the secondary negative electrode of the photoelectric coupler OP1 are in a conducting state, the signal output end ULOST is pulled down to be at a low level, namely, the photoelectric coupler circuit outputs a continuous low level, the control circuit can receive a low level signal and does not generate protection action, when the three-phase voltage is in a phase loss state or under-voltage state, the secondary positive electrode of the photoelectric coupler OP1 and the secondary negative electrode of the photoelectric coupler OP1 are in a disconnecting state, the signal output end ULOST is pulled up to be at a high level through the pull-up resistor R4, namely, the photoelectric coupler circuit outputs a periodic or continuous high level, and the control circuit can receive a high level signal and further generate protection action.
In one embodiment, the 1N4742 type voltage stabilizing diode is selected as the voltage stabilizing diode D8, the clamping voltage is about 12V during breakdown, on one hand, the conduction voltage (1V) of the optical coupler OP1 is supplemented, the problem that the bearable voltage of an optical coupler circuit is too low is solved, on the other hand, the direct current bus voltage is limited, most of the voltage is loaded on the voltage dividing circuit, the voltage born by the rectifying circuit is greatly reduced, and the whole circuit has higher safety and stability.
In one embodiment, the opto-coupler OP1 is a PC817 linear opto-coupler.
In one embodiment, the voltage dividing circuit includes a first resistor R1, a second resistor R2, and a third resistor R3; the front ends of the first resistor R1, the second resistor R2 and the third resistor R3 are respectively connected with one phase line of a three-phase power supply.
The rectifying circuit includes a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5 and a sixth diode D6; an anode of the first diode D1 and a cathode of the second diode D2 are connected to a rear end of the first resistor R1, an anode of the third diode D3 and a cathode of the fourth diode D4 are connected to a rear end of the second resistor R2, an anode of the fifth diode D5 and a cathode of the sixth diode D6 are connected to a rear end of the third resistor R3, cathodes of the first diode D1, the third diode D3 and the fifth diode D5 are connected, and anodes of the second diode D2, the fourth diode D4 and the sixth diode D6 are connected. The three-phase power is integrated into direct current after passing through a rectifying circuit. Since the ac power passing through the first resistor R1 can only flow from the cathode of the first diode D1 to the anode of the first diode D1, but cannot flow through the anode of the second diode D2 to the cathode of the second diode D2, the ac power is converted into dc power by the unidirectional conductivity of the diodes. The full-bridge rectifier circuit is used in the embodiment, all alternating current phases are combined into direct current, alternating current phase information is not lost, and unified detection is facilitated.
In one embodiment, the first resistor R1, the second resistor R2, and the third resistor R3 are each formed by serially connecting a plurality of resistors. The current in the circuit can be limited to about 2mA by connecting a plurality of resistors in series, so that the safety of operators is improved. Meanwhile, the resistors connected in series can play a role in voltage division, the voltage division of the rectifier diode is effectively reduced, and the whole circuit has high safety and stability.
In one embodiment, a filter capacitor C1 is connected between the positive and negative dc poles of the rectifier circuit, and the filter capacitor C1 is a dc support capacitor, which plays a role of filtering, so that the dc in the circuit can be smoother, thereby ensuring the stability of the circuit.
In one embodiment, the filter capacitor C1 is a 10nF ceramic capacitor, the filter capacitor C1 is a capacitor with a small capacitance value, the charging and discharging time is short, and when a phase failure or undervoltage occurs, the voltage in the rectifier circuit can drop rapidly, so that the response rate of the circuit is improved.
In one embodiment, the control circuit comprises a microprocessor MCU, and a state indicating device and a trip switch protection device connected with the microprocessor. When the control circuit receives a low level, the microprocessor MCU sends a circuit normal instruction to the state indicating device, so that the state indicating device displays normal, and the trip switch protection device does not act; when the control circuit receives the high level, the microprocessor MCU sends a circuit abnormal instruction to the state indicating device, so that the state indicating device displays abnormal state, the trip switch protection device is disconnected, and the device is protected.
In one embodiment, the microprocessor MCU is a CPLD (Complex Programmable Logic Device).
The technical conception of the utility model is that: in the input open-phase detection circuit of the cascaded converter unit provided by the embodiment, three-phase alternating current output by the power unit enters the rectification circuit after being subjected to voltage division and current reduction by the voltage division circuit, the three-phase alternating current in the rectifying circuit is integrated into direct current, the optical coupling circuit reacts according to the pulsating voltage of the rectified direct current, when the three-phase power is normal, the rectified direct current voltage keeps high, the photoelectric coupler OP1 is conducted, the optical coupler circuit continuously outputs low level, the control circuit displays that the three-phase alternating current is normal after receiving the low level, when three-phase power is in open-phase or under-voltage, the rectified direct current voltage is remarkably reduced to cause the photoelectric coupler OP1 to be cut off, at the moment, the photoelectric coupler circuit outputs periodic or continuous high level, the control circuit displays the open-phase state after receiving the high level, and the switch is instructed to be switched off to protect the equipment, so that the equipment is prevented from being damaged when the three-phase power is in phase failure or under voltage.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of the changes, substitutions or improvements within the technical scope of the present invention, and all should be covered by the scope of the present invention.
In the description provided herein, numerous specific details are set forth. However, it is understood that embodiments of the application may be practiced without these specific details. In some instances, well-known methods, structures and techniques have not been shown in detail in order not to obscure an understanding of this description.
Claims (10)
1. A cascaded converter unit input phase loss detection circuit is characterized by comprising: the circuit comprises a voltage division circuit, a rectifying circuit, an optical coupling circuit and a control circuit;
the voltage division circuit is used for connecting the power unit of the converter unit, dividing the voltage of each phase line of the three-phase power supply and then introducing the divided voltage into the rectification circuit;
the rectifying circuit rectifies the three-phase power supply into a direct current and inputs the direct current to the optical coupling circuit;
the optical coupling circuit comprises a voltage stabilizing diode, a protection diode and a photoelectric coupler, wherein the cathode of the voltage stabilizing diode is connected with the positive electrode of the direct current, the anode of the voltage stabilizing diode is connected with the positive electrode of the primary side of the photoelectric coupler and the cathode of the protection diode, and the negative electrode of the primary side of the photoelectric coupler and the anode of the protection diode are connected with the negative electrode of the direct current;
the control circuit is connected with the secondary side of the photoelectric coupler.
2. The cascaded converter unit input open-phase detection circuit of claim 1, wherein the optical coupling circuit further comprises a pull-up resistor;
the positive electrode of the secondary side of the photoelectric coupler is connected with a power supply through the pull-up resistor, the negative electrode of the secondary side of the photoelectric coupler is grounded, and the control circuit is connected with the positive electrode of the secondary side of the photoelectric coupler.
3. The cascaded converter cell input open-phase detection circuit according to claim 1, wherein the zener diode is 1N4742 type zener diode.
4. The cascaded converter unit input open-phase detection circuit as claimed in claim 1, wherein the photo coupler is a PC817 linear photo coupler.
5. The cascaded converter unit input open-phase detection circuit of claim 1, wherein the voltage dividing circuit comprises a first resistor, a second resistor and a third resistor; the front ends of the first resistor, the second resistor and the third resistor are respectively connected with one phase line of a three-phase power supply;
the rectifying circuit comprises a first diode, a second diode, a third diode, a fourth diode, a fifth diode and a sixth diode; the anode of the first diode and the cathode of the second diode are connected with the rear end of the first resistor, the anode of the third diode and the cathode of the fourth diode are connected with the rear end of the second resistor, the anode of the fifth diode and the cathode of the sixth diode are connected with the rear end of the third resistor, the cathodes of the first diode, the third diode and the fifth diode are connected, and the anodes of the second diode, the fourth diode and the sixth diode are connected.
6. The cascaded converter unit input open-phase detection circuit of claim 5, wherein the first resistor, the second resistor and the third resistor are respectively formed by connecting a plurality of resistors in series.
7. The cascaded converter unit input open-phase detection circuit of claim 1, wherein a filter capacitor is connected between a direct current positive electrode and a direct current negative electrode of the rectifying circuit.
8. The cascaded converter cell input open-phase detection circuit as claimed in claim 7, wherein said filter capacitor is a 10nF ceramic capacitor.
9. The cascaded converter unit input open-phase detection circuit as claimed in claim 1, wherein the control circuit comprises a microprocessor, and a state indicating device and a trip switch protection device connected with the microprocessor.
10. The cascaded converter unit input open-phase detection circuit of claim 9, wherein the microprocessor is a CPLD.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922193771.8U CN211741424U (en) | 2019-12-09 | 2019-12-09 | Cascaded converter unit input phase loss detection circuit |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201922193771.8U CN211741424U (en) | 2019-12-09 | 2019-12-09 | Cascaded converter unit input phase loss detection circuit |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN211741424U true CN211741424U (en) | 2020-10-23 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201922193771.8U Active CN211741424U (en) | 2019-12-09 | 2019-12-09 | Cascaded converter unit input phase loss detection circuit |
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| CN (1) | CN211741424U (en) |
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