CN110690078B - Zero-phase switch with fault protection function such as diode - Google Patents
Zero-phase switch with fault protection function such as diode Download PDFInfo
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- CN110690078B CN110690078B CN201910939306.6A CN201910939306A CN110690078B CN 110690078 B CN110690078 B CN 110690078B CN 201910939306 A CN201910939306 A CN 201910939306A CN 110690078 B CN110690078 B CN 110690078B
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- 238000001514 detection method Methods 0.000 claims abstract description 18
- 238000000034 method Methods 0.000 claims description 20
- 230000002159 abnormal effect Effects 0.000 abstract description 2
- 230000009286 beneficial effect Effects 0.000 abstract description 2
- 238000010586 diagram Methods 0.000 description 9
- 238000006243 chemical reaction Methods 0.000 description 6
- 239000003990 capacitor Substances 0.000 description 3
- 230000003287 optical effect Effects 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000008033 biological extinction Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000016507 interphase Effects 0.000 description 1
- 230000035772 mutation Effects 0.000 description 1
Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
- H01H47/22—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current for supplying energising current for relay coil
- H01H47/223—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current for supplying energising current for relay coil adapted to be supplied by AC
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H47/00—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current
- H01H47/22—Circuit arrangements not adapted to a particular application of the relay and designed to obtain desired operating characteristics or to provide energising current for supplying energising current for relay coil
- H01H47/32—Energising current supplied by semiconductor device
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- Relay Circuits (AREA)
Abstract
The invention provides a zero-phase switch with fault protection, such as a diode, comprising: the main relay contact protection circuit is formed by connecting an auxiliary relay contact K1 with two diodes D1 and D2 in series, and two ends of the auxiliary relay contact K are connected with the main relay contact K in parallel; the main relay contact detection circuit is formed by connecting an input end of an optocoupler OP with a diode D3 in series, two ends of the optocoupler OP are connected with two ends of a D1 and a D2 in parallel, and an output end of the optocoupler OP is connected to the relay control circuit. The beneficial effects of the invention are as follows: the main contact detection circuit can prevent the switch accident caused by the dead contact of the main relay, and when the switch is in operation, the main contact detection circuit can immediately stop the operation of the main contact when detecting that the contact is in abnormal operation, further expansion of faults is prevented, and the switch is informed of faults, so that the reliability of zero-phase switching such as a diode can be improved.
Description
Technical Field
The invention relates to an alternating current relay switch, in particular to a relay switch which is characterized in that a diode and an auxiliary relay contact are connected in series to realize that the contact of the alternating current relay switch does not generate an arc when being closed or opened, and the relay switch has fault protection and alarm, and the international classification numbers are H01H9/54 and H01H9/56.
Background
The chinese patent application 2013102656141.1 provides a zero-phase switch such as a diode, in which the auxiliary relay contacts are closed first when the switch is turned on/off, so as to ensure that the main relay contacts will not strike fire or arc when they are turned on or off, and the auxiliary relay contacts only work in the instant of the switching action, so that the service life of the auxiliary relay contacts is far longer than that of the main relay contacts. In practical use, the randomness of the action time of the main relay contact is found to be large, and if the closing time of the main relay contact exceeds the time that the auxiliary branch diode is possibly conducted during closing, the main relay contact may be burnt and stuck or the arcing is continuously generated. In addition, the diode and other zero-phase switches are mainly applied to the fields of power supply commutation or commutation, the commutation or commutation without current mutation can be realized, and the switch can be applied to the fields of a power supply switching commutating switch, a transformer on-load voltage regulating switch, a three-phase unbalanced commutation switch and the like. Under the application condition of commutation and commutation, the principle is that the contact of the main relay of the A path is opened, the contact of the main relay of the B path is closed, and auxiliary diode branches are used for freewheeling at the moment of opening to closing, namely, the conversion from the A path to the B path is realized. However, if the a-way relay contact is not opened due to a fault, the B-way relay contact is closed, and an accident of short-circuiting the a-way power supply and the B-way power supply occurs. In order to avoid the commutation short-circuit accident caused by the fact that the main relay contact does not act, chinese patent ZL201520930559.4 discloses a method for detecting whether the main relay contact acts, by checking the current of the main relay contact loop, whether the main relay contact is closed or opened can be confirmed, and the commutation interlock is realized by a single pole double throw relay switch. However, this detection method cannot determine whether the small relay is closed before the main relay contacts are operated, and if the small relay is not closed, the large relay is not protected during the closing and opening operations.
Disclosure of Invention
The invention aims to provide a detection circuit and a control method for improving the reliability of zero-phase switches such as diodes, and the zero-phase switches such as the diodes are protected by judging the closing of auxiliary relay contacts and the closing/opening of main relay contacts.
The invention aims at realizing the following technical scheme:
The zero-phase switch with fault protection such as a diode comprises a main relay contact protection circuit, a main relay contact detection circuit, a main relay contact and a relay control circuit, wherein the main relay contact protection circuit is formed by connecting a fuse tube F, an auxiliary relay contact KD and two diodes D1 and D2 in series, and two ends of the main relay contact are connected with a main relay contact K in parallel; the main relay contact detection circuit is formed by connecting an input end of an optocoupler OP with a diode D3 in series, two ends of the optocoupler OP are connected with two ends of a D1 and a D2 in parallel, and an output end of the optocoupler OP is connected to the relay control circuit.
Further, the main relay contact protection circuit is formed by connecting more than 2 diodes with auxiliary relay contacts in series.
Further, the auxiliary relay contact branch is connected with a fuse F in series, and rated current of the fuse tube is 1/5-1/100 of rated current of the main relay contact.
Furthermore, the power input end of the relay control circuit is connected with the lower end of the auxiliary relay contact branch series fuse, and when the fuse is blown, the relay control circuit has no power supply.
The protection method of the zero-phase switch of the diode and the like comprises the following steps:
Step 1) relay closing process: when the voltage changes to the positive half cycle, if the optocoupler does not output, the small relay contacts are not closed or the diodes are short-circuited, and the control circuit should immediately send out a large relay opening instruction; if the optocoupler is output within the preset closing time period of the large relay, the large relay is not closed, the control circuit opens the small relay in the next negative half cycle of the current, and a fault alarm is sent out;
Step 2) relay opening process: the small relay is closed before the large relay is opened, the large relay is opened in the positive half cycle of the current, and if the optocoupler does not output within the preset opening period of the large relay contact, the relay control circuit stops executing the control instruction of the next step and gives an alarm.
The beneficial effects of the invention are as follows: the main contact detection circuit can prevent the switch accident caused by the dead contact of the main relay, and when the switch is in operation, the main contact detection circuit can immediately stop the operation of the main contact and further expansion of faults when finding that the contact is in abnormal operation, and inform the switch of faults, so that the reliability of zero-phase switches such as diodes can be improved.
Drawings
The invention is described in further detail below with reference to the accompanying drawings.
Fig. 1 is a schematic diagram of a zero-phase switching circuit such as a diode with fault protection according to an embodiment of the present invention;
FIG. 2 is a schematic diagram of a zero-phase switching circuit with a fault protection diode according to an embodiment of the present invention;
FIG. 3 is a schematic diagram of a three-phase unbalanced regulated phase change switch circuit with short-circuit protection according to an embodiment of the present invention;
FIG. 4 is a schematic diagram of a converter switch with short-circuit protection according to an embodiment of the present invention;
fig. 5 is a schematic diagram of a capacitor switching circuit with fuse protection according to an embodiment of the present invention.
Detailed Description
As shown in FIG. 1, the schematic diagram of a zero-phase switch with a fault protection diode and the like according to the embodiment of the invention comprises a main relay contact K, a main relay contact protection circuit, a main relay contact detection circuit and a relay control circuit, wherein the main relay contact protection circuit is formed by connecting an insurance tube F, an auxiliary relay contact KD and a diode D1 and D2 in series, two ends of the main relay contact protection circuit are connected with the main relay contact K in parallel, the main relay contact detection circuit is formed by connecting an input end of an optocoupler OP, a resistor R and a diode D3 in series, two ends of the main relay contact detection circuit are connected with two ends of a D1 and a D2 in parallel, and an output end of the optocoupler OP is connected to the relay control circuit.
The main relay contact detection circuit operates as follows: (1) When the switch is closed, firstly the auxiliary relay contact KD is closed in the negative half cycle, as D1 and D2 are in the reverse direction, no current passes through the main relay contact protection branch, and D3 is also in the reverse direction, no current passes through the main relay contact detection branch, when the voltage is changed from negative to positive, D1, D2 and D3 are conducted, at this time, current is shunted to flow through the auxiliary relay contact detection circuit, and the optocoupler OP has current output. And closing the main relay contact K during the positive half cycle of the voltage to finish the closing process of the switch. If the auxiliary relay contact K1 is not closed, the optocoupler OP does not output pulse current at the moment of positive voltage, the relay control circuit immediately stops closing the main relay contact K or sends out a main relay contact opening instruction, and then sends out a fault alarm; if the main relay contact K is not closed for a predetermined time during the positive half cycle of the voltage, the optocoupler OP continues to have current output, and the relay control circuit will send an opening command to the main relay and open the auxiliary relay contact KD during the negative half cycle of the voltage. In the switch closing process, no matter the auxiliary relay contact is not closed or the main relay contact is not closed or is closed in a delayed manner, the main relay contact is possibly damaged to cause switch faults, and the zero-switch protection circuits such as diodes can prompt the switch faults. (2) When the switch is opened, the auxiliary relay contact is closed, and no current passes through the main relay contact electric shock protection circuit and the main relay contact detection circuit because the main relay contact is in a closed state, the main relay contact K is opened at the positive half cycle of the current, and once the main relay contact K is opened. Current flows through branches KD, D1 and D2 of the auxiliary relay contacts, a branch D3 of the auxiliary relay contacts and an optical coupler OP, so that arc discharge is avoided when the main relay contacts are disconnected, meanwhile, the optical coupler OP has current output, a relay control circuit obtains a signal for disconnecting the main relay contacts, and a process of switching off a switch is completed when the auxiliary relay contacts KD are disconnected in the next negative half cycle of the current. If the main relay contact is not opened at a predetermined time, the relay control circuit immediately stops the action of opening the main relay contact and gives a fault alarm. The resistor R connected in series with the optocoupler branch circuit has the function of preventing the optocoupler branch circuit from being burnt out excessively, the resistance value of the resistor R is 0-1000 omega, and a proper resistance value can be obtained by a common technician through a test.
Fig. 2 is a schematic diagram of a zero-phase switch with a fault protection diode, etc. according to an embodiment of the present invention, a current transformer detects the current of an auxiliary relay contact branch, the output of the transformer is connected to a relay control circuit, and the current transformer can detect the current change of the auxiliary relay contact branch during the closing or opening process of the switch, so as to determine the state of closing or opening the contacts of the main relay. The main relay contacts can be normally closed or opened in a preset time, and the mutual inductor outputs a current signal with corresponding change; if the main relay contact cannot be normally closed or opened within a preset time, the mutual inductor outputs a current signal with corresponding change, and the relay control circuit detects that the main relay contact fails, so that a switch failure alarm can be made. The disadvantage of using the current transformer to realize the main relay contact detection function is that if the diodes D1 and D2 are short-circuited, the current transformer outputs current signals as usual, so that it is not possible to sense whether the diodes D1 and D2 are short-circuited, and the short-circuited condition of the diodes D1 and D2 still continues the switching on or switching off process, which will cause larger faults.
Fig. 3 is a schematic circuit diagram of a zero-phase switch with fault protection, such as a diode, applied to a three-phase commutation switch according to an embodiment of the present invention, where the switch can solve the problem of three-phase imbalance of a low-voltage distribution network. The phase change switch consists of three groups of zero-phase switches such as a diode with fault protection and the like, wherein one ends of the three groups of switches are respectively connected to A, B, C three phases, and the other ends of the three groups of switches are connected with a load in parallel. When the A-way switch is closed, the A phase is used for supplying power; when the B-way switch is closed, the B-phase is used for supplying power, and A, B, C three-way switches can only be closed at the same time, otherwise interphase short circuit can occur. The specific phase change working process is as follows: assuming that the phase change switch is powered by the a phase, the B phase is now switched to be powered by A, B, the a phase advances the B phase by 6.67mS/50Hz, the load is resistive, the auxiliary relay contact KAD is closed first in the negative half cycle of the a phase current during the phase change, the main relay contact KA is opened in the positive half cycle, the optocoupler OPA has level change output to be sent to the phase change relay control circuit when the KA is opened, if the phase change relay control circuit does not receive a change signal of the optocoupler output in a preset time, the phase change relay control circuit determines that the main relay contact KA is not opened, the phase change relay control circuit does not send an instruction for closing the auxiliary relay contact switches KBD and B relay JB, and opens the auxiliary relay contact KAD in the negative half cycle of the current in the following phase change, so that the possibility of A, B phase short circuit when the main relay contact KB is closed can be avoided. Then if KA is closed without problem, the relay control circuit controls the auxiliary relay contact KBD to be closed, when the B-phase voltage is higher than the A-phase voltage, diodes DA1 and DA2 of the auxiliary relay contact branch of the A-way switch are cut off, diodes DB1 and DB2 of the auxiliary relay contact branch of the B-way switch are conducted, the phase change switch smoothly changes phases, then the relay control circuit controls the B-phase main relay contact KB to be closed, and then the auxiliary relay contact KAD of the A-way switch is opened, so that the phase change process is completed. If the auxiliary relay contact KAD of the a-way switch is not disconnected for some reason, when the a-phase voltage is higher than the B-phase voltage, a short circuit occurs between A, B, and then the fuse tube FA connected in series with the auxiliary branch of the a-way switch is quickly fused, so that the occurrence of short circuit accident can be avoided, the capacity of the fuse tube is generally selected to be between 1/5 and 1/100 of the current of the main loop, for example, the normal working current of the switch is 100A, and the fuse tube can be selected to be 5A.
If the phase A and the phase B are in an inverse relationship, the process from the phase A to the phase B and various protection processes can be completed by the ordinary skilled in the art according to the above description, and the description is omitted here.
Fig. 4 is a schematic circuit diagram of a zero-phase switch with fault protection such as a diode for switching power and a converter switch with short-circuit protection according to an embodiment of the present invention, where the power conversion circuit is powered by two power supplies to a load, and when KA is closed, the power conversion circuit is powered by an a power supply, when KB is closed, the power conversion circuit is powered by a B power supply, and when KA and KB are switched, if KA and KB are simultaneously closed, a A, B power supply short-circuit occurs; if KA and KB are disconnected at the same time during commutation, the situation of load outage occurs. In fig. 4, KA and KB each have two auxiliary branches KAD1, KAD2, KBD1 and KBD2, and each switch branch is provided with two auxiliary branches with opposite polarities of diodes, so that A, B power supply can be ensured to perform current conversion in any positive and negative half cycles, and the current conversion principle and process are similar to those of the phase-change switch in fig. 3, and are not repeated.
Fig. 5 shows a capacitor switching switch with fuse protection for capacitor switching, according to an embodiment of the present invention. The two ends 1 and 2 of the relay control circuit are power ends of the relay control circuit, the end 1 is connected between the FA and the KAD of the A-phase switch auxiliary branch, the end 2 is connected between the FC and the KCD of the C-phase switch auxiliary branch, the relay control circuit is equivalent to directly taking electricity from the A, C phases of the three-phase power supply through the fuse FA and the FC, the fuse FA or the FC is blown due to the switching failure, and the relay control circuit cannot continue to work due to the fact that no power supply is provided, so that further expansion of the failure can be avoided.
The invention discloses a diode contact protection compound switch, which is a switch with current zero crossing on/off, and realizes the arc extinction of the switch by zero technology such as a diode. This allows the switch to have smaller volumes, more intelligent protection functions and remote control functions, enabling truly intelligent switching, which would be a revolution in ac power switches.
The present application is not limited to the above-described preferred embodiments, and any person who can obtain other various products and methods according to the present application, however, any change in shape or structure of the products and methods is within the scope of the present application, and all the products and methods having the same or similar technical solutions to the present application are included.
Claims (4)
1. A zero-phase switch with fault protection diode, comprising: the main relay contact protection circuit is formed by connecting an insurance tube F, an auxiliary relay contact KD and two diodes D1 and D2 in series, and two ends of the main relay contact protection circuit are connected with a main relay contact K in parallel; the main relay contact detection circuit is formed by connecting an input end of an optocoupler OP with a diode D3 in series, wherein two ends of the optocoupler OP are connected with two ends of a D1 and a D2 in parallel, and an output end of the optocoupler OP is connected to the relay control circuit; the zero-phase switch with fault protection such as a diode is controlled by the following steps:
Step 1) relay closing process: when the voltage changes to the positive half cycle, if the optocoupler does not output, the small relay contacts are not closed or the diodes are short-circuited, and the control circuit should immediately send out a large relay opening instruction; if the optocoupler is output within the preset closing time period of the large relay, the large relay is not closed, the control circuit opens the small relay in the next negative half cycle of the current, and a fault alarm is sent out;
Step 2) relay opening process: the small relay is closed before the large relay is opened, the large relay is opened in the positive half cycle of the current, and if the optocoupler does not output within the preset opening period of the large relay contact, the relay control circuit stops executing the control instruction of the next step and gives an alarm.
2. The zero-phase switch with fault protection diode and the like according to claim 1, wherein the main relay contact protection circuit is formed by connecting more than 2 diodes in series with auxiliary relay contacts.
3. A zero-phase switch such as a diode with fault protection as claimed in claim 2, wherein the auxiliary relay contact branch is connected in series with a fuse F, the rated current of which is 1/5-1/100 of the rated current of the main relay contact operation.
4. A zero-phase switch such as a diode with fault protection as claimed in claim 3 wherein the power input of the relay control circuit is connected to the lower end of the auxiliary relay contact branch series fuse and the relay control circuit is not powered when the fuse is blown.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910939306.6A CN110690078B (en) | 2019-09-30 | 2019-09-30 | Zero-phase switch with fault protection function such as diode |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910939306.6A CN110690078B (en) | 2019-09-30 | 2019-09-30 | Zero-phase switch with fault protection function such as diode |
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| Publication Number | Publication Date |
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| CN110690078A CN110690078A (en) | 2020-01-14 |
| CN110690078B true CN110690078B (en) | 2024-06-25 |
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| Publication number | Priority date | Publication date | Assignee | Title |
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| CN114459137A (en) * | 2022-01-11 | 2022-05-10 | 珠海格力电器股份有限公司 | Zero-line and fire-line conditioning device of air conditioner, control method of zero-line and fire-line conditioning device and air conditioner |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103928913A (en) * | 2014-03-31 | 2014-07-16 | 华中科技大学 | High-voltage direct-current circuit breaker based on rapid repulsion force mechanism and insulating transformer |
| CN104252995A (en) * | 2013-06-28 | 2014-12-31 | 王海 | Control circuit of diode contact protection combination switch and control method of relay |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6538870B2 (en) * | 2001-02-02 | 2003-03-25 | Eaton Corporation | Circuit breaker and electrical distribution panel employing the same |
| KR101253097B1 (en) * | 2012-11-28 | 2013-04-11 | 중앙제어 주식회사 | Relay circuit system for preventing arc |
| WO2016082704A1 (en) * | 2014-11-25 | 2016-06-02 | 王海 | On-load voltage regulation tap switch for transformer and switch control method |
| JP6713660B2 (en) * | 2016-01-11 | 2020-06-24 | 嶋田 隆一 | Arc-free current switchgear |
| CN106653433B (en) * | 2017-02-08 | 2021-09-17 | 国源容开国际科技（北京）股份有限公司 | High-voltage large-current equal-zero-phase switch and control method |
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Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104252995A (en) * | 2013-06-28 | 2014-12-31 | 王海 | Control circuit of diode contact protection combination switch and control method of relay |
| CN103928913A (en) * | 2014-03-31 | 2014-07-16 | 华中科技大学 | High-voltage direct-current circuit breaker based on rapid repulsion force mechanism and insulating transformer |
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