CN201038780Y - Three-phase co-supplement type composite switch - Google Patents

Abstract

The utility model relates to a three-phase common-compensation intelligent compound switch. A signal control input circuit is connected with a program control circuit. Silicon symmetrical switch triggered circuits and magnetic latching relay triggered circuits are respectively connected with the program control circuit. The magnetic latching relay triggered circuits are respectively connected with a magnetic latching relay, and the silicon symmetrical switch triggered circuits are respectively connected with a silicon symmetrical switch. A-phase is singly provided with the magnetic latching relay for switching and loading works and B-phase and C-phase are respectively connected in parallel with the silicon symmetrical switches through the contacts of the magnetic latching relays for switching and loading works. The utility model completely eliminates the problems of electric arc emergence and contact agglomeration. The utility model has a safe and reliable capability and can save energy and protect environment, without power cost, heating and harmonic pollutions.

Description

Three-phase co-complementary intelligent composite switch

Technical field:

The utility model relates to a switching control device when a power capacitor is used for reactive power compensation of a low-voltage power grid, in particular to an intelligent composite switch specially designed for a capacitor with a delta connection method.

Background technique:

In the past, AC contactors and thyristor non-contact switches were generally used as components for switching low-voltage reactive power compensation power capacitors. When using an AC electromagnetic contactor, the contacts of the contactor are easy to burn out due to the inrush current generated at the moment when the capacitor is turned on and off; when the capacitor is put into operation, the electromagnetic coil of the contactor itself not only has power consumption, but also may burn out due to heat Extremely strong, so the service life is short and the safety is poor. When the SCR non-contact switch is used, its operating power consumption is high and it emits a large amount of heat. Fan cooling measures must be taken, which will also invisibly increase the power consumption of the fan. Once the fan fails, the SCR will burn out quickly; Another more serious problem is that the thyristor will produce harmonic pollution when it enters the power grid.

Utility model content:

The purpose of the utility model is to provide a three-phase co-complementary intelligent composite switch, which solves the problems of the above two switch elements, and is safe and reliable.

In order to achieve the above object, the solution adopted by the utility model is: a three-phase co-complementary intelligent composite switch, the control signal input circuit is connected with the program control circuit, the bidirectional thyristor trigger circuit, the magnetic latching relay trigger circuit are connected with the program control circuit respectively The control circuit is connected, the magnetic latching relay trigger circuit is respectively connected with the magnetic latching relay, the bidirectional thyristor trigger circuit is respectively connected with the bidirectional thyristor, the single magnetic latching relay of A phase is responsible for on-off and carrying work, and the B phase and C phase are respectively The contacts of the magnetic latching relay and the bidirectional thyristor are connected in parallel to form the on-off and load-carrying work; the control signal input circuit composed of optocoupler elements and integrated circuits receives the compensation three-phase capacitor switching and switching signals sent by the compensation controller, After photoelectric isolation processing, the signal is sent to the program control circuit; the program control circuit programmed by the single-chip microcomputer, when receiving the command to invest in the compensation three-phase capacitor, first starts the A-phase magnetic latching relay trigger circuit, so that the A-phase magnetic latching relay Closed, when the three-phase load does not form a loop, first connect the A phase of the compensation three-phase capacitor to the power grid, then make a logical judgment, select the zero-crossing point, and start the B-phase and C-phase bidirectional thyristor trigger circuit, so that Phase B and phase C bidirectional thyristor conduction, and then start B phase, C phase magnetic latching relay trigger circuit output pulse positive voltage, B phase, C phase magnetic latching relay pulls in, the normally open contact turns into a closed state, and maintains , the program control circuit finally instructs the B-phase and C-phase bidirectional thyristor trigger circuits to turn off the bidirectional thyristor, and the conduction operation of the compensation three-phase capacitor is performed by the closed contact of the magnetic latching relay; when the program control circuit receives When cutting off the command to compensate the three-phase capacitor, first start the B-phase and C-phase bidirectional thyristor trigger circuits to turn on the bidirectional thyristor, and then start the B-phase and C-phase magnetic latching relay trigger circuits to output pulse negative voltage, so that the B-phase , Phase C magnetic latching relay is released, and its closed contact is converted into a normally open state; after the program control circuit makes a logical judgment, selects the zero-crossing point, instructs the B-phase and C-phase bidirectional thyristor trigger circuit to close the bidirectional thyristor, and compensates the three Phase B and phase C of the phase capacitor leave the grid, and finally the program control circuit instructs the phase A magnetic latching relay to trigger the circuit to output pulse negative voltage, so that the phase A magnetic latching relay is released, and its closed contact is converted into a normally open state to compensate the three-phase capacitor Cut off the grid completely.

The utility model has the advantages of: adopting program control, bidirectional thyristor zero-crossing switching, and magnetic latching relay contact closure to ensure the operation of compensating three-phase capacitors, completely eliminating the problems of arc generation and contact sintering, and safe Reliable; bidirectional thyristor zero-crossing switching is completed instantly, no power consumption, no heat, no harmonic pollution, energy saving and environmental protection; compared with the use of contactors, the flexibility of three magnetic latching relays is very good, especially Phase A is connected first before no loop is formed. Similarly, phase A is disconnected after the loop is cut off, and the switching and switching actions are completed in a state of no current. The degree of intelligence is high and the design is very reasonable; the function is electronic. Finally, a lot of resources (non-ferrous metals) are saved.

Description of drawings:

Fig. 1 is a structural schematic diagram of this embodiment.

In the figure: DL1-control signal input circuit, DL2-program control circuit, DL3-bidirectional thyristor trigger circuit, DL4-magnetic latching relay trigger circuit, DL5-power supply circuit, DL6-fault and operation monitoring circuit, DL7-voltage loss And phase loss protection circuit, DL8-no-load protection circuit, JD1-magnetic latching relay, JD2-magnetic latching relay, JD3-magnetic latching relay, KB-bidirectional thyristor, KC2-bidirectional thyristor, C1, C2, C3 - Compensation for three-phase capacitors.

Detailed ways:

Below in conjunction with embodiment and accompanying drawing thereof, the utility model is described again.

Referring to Fig. 1, a three-phase co-compensation intelligent composite switch, the control signal input circuit DL1 is connected to the program control circuit DL2, the bidirectional thyristor trigger circuit DL3, and the magnetic latching relay trigger circuit DL4 are respectively connected to the program control circuit DL2, and the magnetic The holding relay trigger circuit DL4 is respectively connected with the magnetic holding relays JD1, JD2, and JD3, and the bidirectional thyristor trigger circuit is respectively connected with the bidirectional thyristor. The phases are composed of the contacts of the magnetic latching relays JD2 and JD3 in parallel with the bidirectional thyristor KB and KC, which are responsible for on-off and load-carrying work; the control signal input circuit DL1 composed of optocoupler elements and integrated circuits receives the signal sent by the compensation controller. Compensation of the three-phase capacitor C1, C2, C3 switching signal, the signal is sent to the program control circuit DL2 after photoelectric isolation processing; the program control circuit DL2 programmed by the single-chip computer, when receiving the input compensation three-phase capacitor C1, C2, When the command of C3 is given, first start the trigger circuit DL4 of the phase A magnetic latching relay to close the phase A magnetic latching relay JD1. In the case that the three-phase load does not form a loop, first let the phase A of the compensation three-phase capacitors C1, C2, and C3 Connect to the power grid, then make a logical judgment, select the zero-crossing point, start the B-phase, C-phase triac trigger circuit DL3, make the B-phase, C-phase triac KB, KC conduction, and then start the B-phase, C-phase Phase magnetic latching relay trigger circuit DL4 outputs positive pulse voltage, phase B and phase C magnetic latching relays JD2 and JD3 pull in, normally open contacts are converted to closed state, and hold, program control circuit DL2 finally indicates B phase, C phase bidirectional The thyristor trigger circuit DL3 closes the bidirectional thyristor KB, KC, and the conduction operation of the compensation three-phase capacitors C1, C2, and C3 is performed by the closed contacts of the magnetic latching relays JD1, JD2, and JD3; when the program control circuit When DL2 receives the command to cut off the compensation three-phase capacitors C1, C2 and C3, it first starts the B-phase and C-phase bidirectional thyristor trigger circuit DL3 to turn on the bidirectional thyristor KB and KC, and then starts the B-phase and C-phase magnetic The holding relay trigger circuit DL4 outputs pulse negative voltage to release the B-phase and C-phase magnetic holding relays JD2 and JD3, and their closed contacts are converted into normally open states; after the program control circuit DL2 makes a logical judgment, select the zero-crossing point and indicate the B-phase , Phase C bidirectional thyristor trigger circuit DL3 turns off bidirectional thyristor KB, KC, compensates phase B and phase C of three-phase capacitors C1, C2, and C3 to leave the power grid, and finally program control circuit DL2 instructs phase A magnetic latching relay trigger circuit DL4 outputs pulsed negative voltage to release phase A magnetic latching relay JD1, and its closed contact is converted into a normally open state, and the compensation three-phase capacitors C1, C2, and C3 are completely disconnected from the power grid.

Referring to Figure 1, the working principle of the compound switch is briefly described as follows: when K+ and K- generate level signals (from the upper level compensation controller), the signals are sent to the program control circuit through the photoelectric coupling process of the control signal input circuit DL1 DL2, DL2 indicates that the phase A magnetic latching relay trigger circuit DL4, output pulse positive voltage, JD1 pulls in, its normally open contact is converted into a closed state, and maintains, and the A phase of the compensation three-phase capacitor C1, C2, C3 is connected to the power grid At this time, phase B and phase C are not connected, and a three-phase circuit has not yet been formed, so that no current passes through the contact of JD1, and no arc is generated; DL2 makes a logical judgment, selects a zero-crossing point, and instructs the bidirectional thyristor trigger circuit DL3, Trigger KB and KC to be turned on, and the phases B and C of the three-phase capacitors C1, C2, and C3 will be connected to the power grid at the same time. Then, DL2 will instruct the magnetic latching relay trigger circuit DL4 to output a positive pulse voltage to make JD2 and JD3 pull in. The normally open contact is converted into a closed state and kept in parallel with KB and KC respectively; the program control circuit DL2 finally instructs the B-phase and C-phase bidirectional thyristor trigger circuit DL3 to close the bidirectional thyristor KB and KC. The instantaneous disconnection process is completed by KB and KC, and the conduction operation of the compensation three-phase capacitors C1, C2, and C3 is performed by the closed contacts of the magnetic latching relays JD1, JD2, and JD3; when K+, K- are on the level When the signal disappears (the instruction to cut off the compensation three-phase capacitors C1, C2, and C3), the control signal input circuit DL1 immediately conveys this instruction to the program control circuit DL2, and DL2 instructs the B-phase and C-phase bidirectional thyristor trigger circuit DL3 to conduct Pass the bidirectional thyristor KB, KC, and then start the B-phase, C-phase magnetic latching relay trigger circuit DL4 to output pulse negative voltage, so that the B-phase, C-phase magnetic latching relay JD2, JD3 are released, and their closed contacts are converted into normally open state, exiting the load circuit; after the program control circuit DL2 makes a logical judgment, selects the zero-crossing point, instructs the B-phase and C-phase triac trigger circuit DL3 to close the triac KB, KC, and compensates the three-phase capacitors C1, C2, Phase B and phase C of C3 leave the power grid, and finally the program control circuit DL2 instructs the phase A magnetic latching relay trigger circuit DL4 to output pulse negative voltage, so that the phase A magnetic latching relay JD1 is released, and its closed contact is converted into a normally open state. In the state of the three-phase circuit, the A-phase load is cut off, and the compensation three-phase capacitors C1, C2, and C3 are completely cut off from the power grid.

Referring to Fig. 1, the program control circuit DL2 is connected to a power supply circuit DL6, and DL6 is responsible for the public power supply of the composite switch and provides the necessary DC regulated power supply.

Referring to FIG. 1 , the program control circuit DL2 is connected with a voltage loss and phase loss protection circuit DL7 composed of a monitoring circuit and a voltage comparison circuit. DL7 feeds back the voltage of each phase to DL2. When the circuit loses phase, the switch refuses to close; if there is a phase loss after it is connected, it will automatically retire; when it is connected and encounters a sudden power failure (loss of voltage), it will automatically trip and disconnect.

Referring to Fig. 1, the program control circuit DL2 is connected with a no-load protection circuit DL8 composed of a monitoring circuit and an inverter. DL8 feeds back load information to DL2. If no load is connected, DL2 stops executing any program.

Referring to Fig. 1, the program control circuit DL2 is connected with a fault and operation monitoring circuit DL6 composed of an integrated circuit and a light-emitting diode. DL6 automatically monitors the operating states of K1, K2, K3 and JD1, JD2, and JD3. If there is a fault, the light-emitting diode (fault indicator light) will light up, and prompt DL2 to instruct the relevant circuit to react so that the switch refuses to close or automatically withdraws and disconnects.

Claims (2)

1. a three-phase is mended the formula intelligent compound switch altogether, it is characterized in that: the control signal input circuit is connected with sequence circuit, bidirectional triode thyristor circuits for triggering, magnetic latching relay circuits for triggering are connected with sequence circuit respectively, the magnetic latching relay circuits for triggering are connected with magnetic latching relay respectively, the bidirectional triode thyristor circuits for triggering are connected with bidirectional triode thyristor respectively, A singly has magnetic latching relay to be responsible for break-make, carrying work mutually, and B phase, C constitute responsible break-make, carrying work by the contact of magnetic latching relay is in parallel with bidirectional triode thyristor respectively mutually; Thrown, cut signal from the compensation three-phase capacitor that compensating controller sends by the control signal input circuit reception that photoelectricity coupling element and integrated circuit are formed, signal is sent to sequence circuit after the photoelectricity isolation processing; The sequence circuit that adds programming by single-chip microcomputer, when receiving the instruction of input compensation three-phase capacitor, start A phase magnetic latching relay circuits for triggering earlier, make A phase magnetic latching relay closure, do not form in threephase load under the situation in loop, allow the A of compensation three-phase capacitor insert in the electrical network mutually earlier, carry out logic determines then, select zero crossing, start the B phase, C phase bidirectional triode thyristor circuits for triggering, make the B phase, the B phase is restarted in the conducting of C phase bidirectional triode thyristor, C phase magnetic latching relay circuits for triggering output pulse positive voltage, the B phase, the adhesive of C phase magnetic latching relay, normally opened contact is converted to closure state, and keep, sequence circuit is indicated the B phase at last, C phase bidirectional triode thyristor circuits for triggering are closed bidirectional triode thyristor, and the conducting operation work of compensation three-phase capacitor is promptly carried out by the closing contact of magnetic latching relay; When sequence circuit receives the instruction of cutting off the compensation three-phase capacitor, start B phase, C phase bidirectional triode thyristor circuits for triggering conducting bidirectional triode thyristor earlier, and then start B phase, C phase magnetic latching relay circuits for triggering output pulse negative voltage, B phase, C phase magnetic latching relay are discharged, and its closing contact converts normally open to; After sequence circuit carries out logic determines, select zero crossing, indication B phase, C phase bidirectional triode thyristor circuits for triggering are closed bidirectional triode thyristor, B phase, the C of compensation three-phase capacitor leave electrical network mutually, final program control circuit indication A phase magnetic latching relay circuits for triggering output pulse negative voltage, A phase magnetic latching relay is discharged, and its closing contact converts normally open to, and the compensation three-phase capacitor thoroughly cuts off electrical network.

2. three-phase according to claim 1 is mended the formula intelligent compound switch altogether, it is characterized in that: decompression that described sequence circuit also is connected with power circuit respectively, be made up of observation circuit and voltage comparator circuit and open-phase protection circuit, the no-load protection circuit of being made up of observation circuit and inverter, fault and the operation monitoring circuit be made up of integrated circuit and light-emitting diode.

Images