A control method, system and device for low-voltage power source spare automatic switching

Abstract

The application discloses a control method, system and device of a low-voltage power source spare automatic throw-in. The method comprises the following steps: determining the load-carrying state of the incoming line side of a working power source switch, the electrified state of a power bus section and the electrified state of the incoming line side of a spare power source switch; when the working power source switch is closed, the spare power source switch is opened and the power bus section is electrified, controlling the first time relay to be powered on; when the spare power source switch is opened, the incoming line side of the spare power source switch is electrified, the incoming line side of the working power source switch is not loaded, the power bus section is not electrified and the first time relay is powered on for a certain time, controlling the second time relay and the third time relay to be powered on; when the working power source switch is closed and the second time relay is powered on for a certain time, controlling the working power source switch to be opened by using the tripping coil of the working power source switch; and when the working power source is opened and the third time relay is powered on for a certain time, controlling the spare power source switch to be closed by using the closing coil of the spare power source switch.

Description

Technical Field

[0001] This application relates to the field of electrical technology, and in particular to a control method, system and device for automatic switching of low-voltage power supply. Background Technology

[0002] Automatic transfer switch (ATS) is short for automatic switching on of backup power. To improve power supply reliability, most low-voltage power supply systems now employ a dual-power supply structure. When the main power supply fails, normal power supply can be ensured by switching to the backup power supply.

[0003] Currently, backup power switching can be achieved by installing microprocessor-based automatic transfer switch (ATS) or fast switching devices. However, these microprocessor-based devices are expensive, bulky, and involve numerous wiring connections. Therefore, some projects do not install such devices and must rely on manual operation to switch backup power. Thus, how to achieve low-voltage backup power automatic transfer reliably and at low cost has become an urgent problem to be solved. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a control method, system, and device for automatic transfer of low-voltage power supplies, which can reliably and cost-effectively achieve automatic transfer of low-voltage backup power.

[0005] The embodiments of this application disclose the following technical solutions:

[0006] This application provides a control method for automatic switching of a low-voltage power supply backup power supply, which is applied to the automatic switching control of the backup power supply in a low-voltage power supply system. The low-voltage power supply system includes: a working power supply, a working power supply switch, a backup power supply, a backup power supply switch, and a power bus section. The working power supply is connected to the power bus section through the working power supply switch, and the backup power supply is connected to the power bus section through the backup power supply switch.

[0007] The method includes:

[0008] Determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch;

[0009] When the working power switch is closed, the backup power switch is open, and the power bus section is energized, the first time relay is energized.

[0010] After the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the first time relay is energized for a first preset time, the second time relay and the third time relay are energized.

[0011] After the power switch is closed and the second time relay is energized for a second preset time, the power switch is opened by controlling the trip coil of the power switch to open.

[0012] After the working power switch is turned off and the third time relay is energized for a third preset time, the backup power switch is closed by using the closing coil of the backup power switch.

[0013] Optionally, determining the load state of the incoming side of the working power switch, the energized state of the power bus section, and the energized state of the incoming side of the standby power switch includes:

[0014] The load status of the incoming line side of the working power switch is determined by using a current transformer and a current relay, the energized status of the power bus section is determined by using a first voltage relay, and the energized status of the incoming line side of the standby power switch is determined by using a second voltage relay.

[0015] Optionally, controlling the first time relay to energize when the working power switch is closed, the backup power switch is open, and the power bus section is energized includes:

[0016] When the first voltage relay determines that the power bus section is energized, it controls the corresponding contact of the first voltage relay to close.

[0017] When the working power switch is closed, the backup power switch is open, and the contact corresponding to the first voltage relay is closed, the first time relay is energized.

[0018] Optionally, the step of controlling the second and third time relays to energize after the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the first time relay is energized for a first preset time includes:

[0019] When the second voltage relay determines that the incoming line side of the backup power switch is energized, it controls the corresponding contact of the second voltage relay to close.

[0020] When the current transformer and the current relay determine that there is no load on the incoming side of the working power switch, control the corresponding contacts of the current transformer and the current relay to close.

[0021] When the first voltage relay determines that the power bus section is not energized, it controls the corresponding contact of the first voltage relay to close.

[0022] After the backup power switch is turned off, the contacts corresponding to the second voltage relay are closed, the contacts corresponding to the current transformer and the current relay are closed, the contacts corresponding to the first voltage relay are closed, and the first time relay is energized for a first preset time, the second time relay and the third time relay are energized.

[0023] Optionally, the method further includes:

[0024] After the backup power switch is turned off and the first time relay is energized for a first preset time, the intermediate relay is energized.

[0025] When the backup power switch is off, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the intermediate relay is energized, the second time relay and the third time relay are energized.

[0026] Optionally, an alternative switch is provided, and the method further includes:

[0027] After the backup power switch is turned off, the incoming side of the backup power switch is energized, the alternative switch is closed, and the first time relay is energized for a first preset time, the second time relay and the third time relay are energized.

[0028] Optionally, the method further includes:

[0029] The trip coil of the power switch is controlled to stop working by using the first hard pressure plate.

[0030] Optionally, the method further includes:

[0031] The closing coil of the backup power switch is stopped by using the second hard pressure plate.

[0032] This application embodiment also provides a control system for automatic transfer of low-voltage power supply, including: a low-voltage power supply system, and further including: a first time relay, a second time relay, a third time relay, a trip coil of the working power switch, and a closing coil of the backup power switch;

[0033] The low-voltage power supply system includes: a working power supply, a working power supply switch, a backup power supply, a backup power supply switch, and a power bus section. The working power supply is connected to the power bus section through the working power supply switch, and the backup power supply is connected to the power bus section through the backup power supply switch.

[0034] The first time relay is connected to the second time relay, the first time relay is connected to the third time relay, the second time relay is connected to the trip coil of the working power switch, and the third time relay is connected to the closing coil of the standby power switch.

[0035] The control system is used for:

[0036] Determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch;

[0037] When the working power switch is closed, the backup power switch is open, and the power bus section is energized, the first time relay is energized.

[0038] After the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the first time relay is energized for a first preset time, the second time relay and the third time relay are energized.

[0039] After the power switch is closed and the second time relay is energized for a second preset time, the power switch is opened by controlling the trip coil of the power switch to open.

[0040] After the working power switch is turned off and the third time relay is energized for a third preset time, the backup power switch is closed by using the closing coil of the backup power switch.

[0041] This application embodiment also provides a control device for automatic switching of low-voltage power supply backup power, which is used to control the automatic switching of backup power in a low-voltage power supply system. The low-voltage power supply system includes: a working power supply, a working power supply switch, a backup power supply, a backup power supply switch, and a power bus section. The working power supply is connected to the power bus section through the working power supply switch, and the backup power supply is connected to the power bus section through the backup power supply switch.

[0042] The device includes:

[0043] The status determination module is used to determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch.

[0044] The first control module is used to control the first time relay to be energized when the working power switch is closed, the backup power switch is open, and the power bus section is energized.

[0045] The second control module is used to control the second and third time relays to be energized after the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not loaded, the power bus section is not energized, and the first time relay is energized for a first preset time.

[0046] The third control module is used to control the working power switch to open by using the trip coil of the working power switch after the working power switch is closed and the second time relay is energized for a second preset time.

[0047] The fourth control module is used to control the backup power switch to close using the closing coil of the backup power switch after the working power switch is turned off and the third time relay is energized for a third preset time.

[0048] Compared with the prior art, this application has the following beneficial effects:

[0049] This application sets the states of various switches and the energized states of various positions as conditions for relay energization, ensuring that the relay is energized only under reliable conditions. Furthermore, it comprehensively utilizes multiple relays to control the trip coil of the working power switch and the closing coil of the standby working power switch, and sets the relay delay time, thereby enabling more reliable automatic switching of low-voltage standby power. At the same time, the relays are inexpensive, thus enabling low-voltage standby power automatic switching at a low cost and with high reliability.

[0050] The low-voltage power supply automatic transfer control system and device provided in this application can achieve the above-mentioned beneficial effects. Attached Figure Description

[0051] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0052] Figure 1 A flowchart of a control method for automatic transfer switching of a low-voltage power supply provided in an embodiment of this application;

[0053] Figure 2 A structural diagram of a low-voltage power supply system provided in this application embodiment;

[0054] Figure 3 A relay control circuit diagram provided for an embodiment of this application;

[0055] Figure 4A control trip circuit diagram provided in this application embodiment;

[0056] Figure 5 A control closing circuit diagram provided in an embodiment of this application;

[0057] Figure 6 A control system structure diagram of a low-voltage power supply automatic transfer switch provided in an embodiment of this application;

[0058] Figure 7 This is a structural diagram of a low-voltage power supply automatic transfer control device provided in an embodiment of this application. Detailed Implementation

[0059] As described above, current low-voltage backup power supplies require manual activation or the use of expensive microcomputer-based automatic backup power switching devices.

[0060] Through research, the inventors have provided a control method, system, and device for automatic transfer of low-voltage power supply backup power, which can reliably and cost-effectively achieve automatic transfer of low-voltage backup power supply.

[0061] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present application.

[0062] Method Implementation Examples

[0063] See Figure 1 The figure is a flowchart of a low-voltage power supply automatic transfer control method provided in an embodiment of this application, including the following steps:

[0064] S101, determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch.

[0065] It should be noted that, in the embodiments provided in this application, the load status of the incoming side of the working power switch can be determined by setting a current transformer and a current relay, the energized status of the power bus section can be determined by setting a first voltage relay, and the energized status of the incoming side of the standby power switch can be determined by setting a second voltage relay. Determining the energized status involves determining whether there is voltage; if there is voltage, the status is energized. Determining the load status involves determining whether there is both voltage and current; if there is both voltage and current, the status is load.

[0066] Specifically, as an example, such as Figure 2 This figure is a structural diagram of a low-voltage power supply system provided in an embodiment of this application. The 10kV power supply, together with the main working power switch DL1 and the working transformer, constitutes the working power supply. The 10kV power supply, together with the main standby power switch DL2 and the standby transformer, constitute the standby power supply. QF1 is the working power switch, and QF2 is the standby power switch. A current transformer and a current relay AJ are installed on the incoming side of the working power switch to determine the load status of the working power supply incoming side. A first voltage relay VJ1 is installed on the power bus section to determine the energized status of the power bus section. A second voltage relay VJ2 is installed on the incoming side of the standby power switch to determine the energized status of the standby power switch incoming side.

[0067] S102, when the working power switch is closed, the backup power switch is open, and the power bus section is energized, the first time relay is energized.

[0068] In the embodiments provided in this application, as an example, the first time relay can be energized when the working power switch is closed and the backup power switch is open, thus energizing the power bus section, through a circuit.

[0069] Specifically, such as Figure 3 This figure is a relay control circuit diagram provided in an embodiment of this application. A DC power supply is used as the control power source, allowing control to continue even when the low-voltage power supply system fails, thus improving control reliability. A changeover switch SA is provided to control the relay control circuit to be in use or out of use. Before the working power switch QF1 is normally closed, the changeover switch SA is operated to be in use; before the working power switch QF1 is normally open, the changeover switch SA is operated to be out of use.

[0070] like Figure 3 As shown in the charging circuit diagram, when the working power switch QF1 is closed, the QF1 contact is closed; this contact is normally open. When the standby power switch QF2 is open, the QF2 contact is closed; this contact is normally closed. When the first voltage relay VJ1 determines that the power bus section is energized, the normally open VJ1 contact closes. When all the above contacts are closed, the first time relay KT1 is energized.

[0071] S103, after the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not loaded, the power bus section is not energized, and the first time relay is energized for a first preset time, control the second time relay and the third time relay to be energized.

[0072] Specifically, in the embodiments provided in this application, as an example, the second and third time relays can be energized by means of a circuit after the backup power switch is turned off, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not loaded, the power bus section is not energized, and the first time relay is energized for a first preset time.

[0073] like Figure 3 As shown in the action judgment circuit, when the standby power switch is open, contact QF2 closes; this contact is normally closed. After the first time relay KT1 is energized for a first preset time, contact KT1 closes; this contact is normally open. When the second voltage relay VJ2 determines that the incoming side of the standby power switch is energized, contact VJ2 closes; this contact is normally open. When the current transformer and current relay AJ determine that the incoming side of the working power switch is not under load, contact AJ closes; this contact is normally closed. When the first voltage relay VJ1 determines that the power bus section is not energized, normally closed contact VJ1 closes. When all the above contacts are closed, the second time relay KT2 and the third time relay KT3 are energized.

[0074] To prevent the normally open contact of the first voltage relay VJ1 from opening and causing the first time relay KT1 to lose power when the power bus section fails, the following method can be used: Figure 3 The intermediate relay KA is shown in the self-locking circuit and is equipped with a KA contact. When the contact of the backup power switch QF2 is closed and the contact of the first time relay KT1 is closed, the intermediate relay KA is energized, and its contact KA is closed when the intermediate relay KA is energized.

[0075] To enable operation when normal power switching is required, the following methods can be used: Figure 3 The switch SB shown in the second row of the circuit can be closed by controlling the switch SB to achieve normal switching when normal power is required.

[0076] S104, after the power switch is closed and the second time relay is energized for a second preset time, the power switch is opened by using the trip coil of the power switch.

[0077] It should be noted that, in the embodiments provided in this application, as an example, the working power switch can be turned off by using the trip coil of the working power switch to achieve the following: after the working power switch is closed and the second time relay is energized for a second preset time, the working power switch can be turned off by using a circuit.

[0078] like Figure 4This figure shows a control tripping circuit diagram provided in an embodiment of this application. LP1 is a first hard pressure plate that controls the tripping coil TQ of the power switch to stop working. Without considering the first hard pressure plate LP1, when the power switch QF1 is closed, the QF1 contact closes; this contact is a normally open contact. After the second time relay KT2 is energized for a second preset time, the KT2 contact closes; this contact is also a normally open contact. When all the above contacts are closed, the tripping coil TQ of the power switch is energized, thereby controlling the power switch to trip.

[0079] S105, after the working power switch is turned off and the third time relay is energized for a third preset time, the backup power switch is controlled to close using the closing coil of the backup power switch.

[0080] It should be noted that, in the embodiments provided in this application, as an example, the backup power switch can be closed by means of the closing coil of the backup power switch after the working power switch is turned off and the third time relay is energized for a third preset time.

[0081] like Figure 5 This figure shows a control closing circuit diagram provided in an embodiment of this application. LP2 is a second hard pressure plate that controls the closing coil HQ of the standby power switch to stop working. Without considering the second hard pressure plate LP2, when the working power switch QF1 is open, the normally closed contact QF1 closes; after the third time relay KT3 is energized for a third preset time, the contact of KT3 closes; this contact is a normally open contact. When all the above contacts are closed, the closing coil HQ of the standby power switch is energized, thereby controlling the closing of the standby power switch.

[0082] It should be noted that, in this embodiment of the application, a third preset time can be set to be greater than the second preset time. Combined with the setting of the normally closed QF1 contact in the control closing circuit, it can ensure that the working power switch is disconnected first and then the backup power switch is closed, thereby preventing the working power supply and the backup power supply from working at the same time.

[0083] This application provides a low-voltage power supply automatic transfer control method. By setting the closing of the working power switch, the opening of the backup power switch, and the energization of the power bus section as the energizing conditions for the first time relay, it can prevent the backup power supply from continuing to connect to the faulty power bus after the working power switch trips due to a power bus fault. By setting the closing of the normally closed contact corresponding to the backup power switch as the energizing condition for the second and third time relays, it can be ensured that the second and third time relays are no longer energized after the backup power switch is closed, thus ensuring that the automatic transfer of the backup power supply is only activated once. By setting intermediate relays and their contacts, it can be prevented that the normally open contact of the first voltage relay will open when the power bus section loses power, causing the first time relay to lose power. Furthermore, because the relays are inexpensive, the low-voltage power supply automatic transfer control method provided in this application can achieve low-cost and reliable automatic transfer of low-voltage backup power.

[0084] System Implementation Examples

[0085] See Figure 6 This figure is a structural diagram of a low-voltage power supply automatic transfer control system provided in an embodiment of this application, used to control a low-voltage power supply system. The low-voltage power supply automatic transfer control system includes: a first time relay 601, a second time relay 602, a third time relay 603, a trip coil 604 of the working power switch, and a closing coil 605 of the standby power switch;

[0086] The low-voltage power supply system includes: a working power supply, a working power supply switch, a backup power supply, a backup power supply switch, and a power bus section. The working power supply is connected to the power bus section through the working power supply switch, and the backup power supply is connected to the power bus section through the backup power supply switch.

[0087] The first time relay 601 is connected to the second time relay 602, the first time relay 601 is connected to the third time relay 603, the second time relay 602 is connected to the trip coil 604 of the working power switch, and the third time relay 603 is connected to the closing coil 605 of the standby power switch.

[0088] The control system is used for:

[0089] Determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch;

[0090] When the working power switch is closed, the backup power switch is open, and the power bus section is energized, the first time relay 601 is energized.

[0091] After the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not loaded, the power bus section is not energized, and the first time relay is energized for a first preset time, the second time relay 602 and the third time relay 603 are energized.

[0092] After the power switch is closed and the second time relay 602 is energized for a second preset time, the power switch is controlled to open by the trip coil 604 of the power switch.

[0093] After the working power switch is turned off and the third time relay 603 is energized for a third preset time, the backup power switch is controlled to close by the closing coil 605 of the backup power switch.

[0094] Optionally, determining the load state of the incoming side of the working power switch, the energized state of the power bus section, and the energized state of the incoming side of the standby power switch includes: determining the load state of the incoming side of the working power switch using a current transformer and a current relay, determining the energized state of the power bus section using a first voltage relay, and determining the energized state of the incoming side of the standby power switch using a second voltage relay.

[0095] Optionally, controlling the first time relay to be energized when the working power switch is closed, the backup power switch is open, and the power bus section is energized includes: controlling the contacts corresponding to the first voltage relay to close when the first voltage relay determines that the power bus section is energized; and controlling the first time relay to be energized when the working power switch is closed, the backup power switch is open, and the contacts corresponding to the first voltage relay are closed.

[0096] Optionally, the step of controlling the second and third time relays to be energized after the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is unloaded, the power bus section is unenergized, and the first time relay is energized for a first preset time includes: when the second voltage relay determines that the incoming side of the backup power switch is energized, controlling the corresponding contact of the second voltage relay to close; when the current transformer and the current relay determine that the incoming side of the working power switch is unloaded, controlling the corresponding contacts of the current transformer and the current relay to close; when the first voltage relay determines that the power bus section is unenergized, controlling the corresponding contact of the first voltage relay to close; and after the backup power switch is disconnected, the corresponding contacts of the second voltage relay are closed, the corresponding contacts of the current transformer and the current relay are closed, the corresponding contacts of the first voltage relay are closed, and the first time relay is energized for a first preset time, controlling the second and third time relays to be energized.

[0097] Optionally, the control system is further configured to control the intermediate relay to be energized after the backup power switch is turned off and the first time relay is energized for a first preset time; and to control the second time relay and the third time relay to be energized when the backup power switch is turned off, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not loaded, the power bus section is not energized, and the intermediate relay is energized.

[0098] Optionally, the control system may also be equipped with a substitute switch. After the substitute switch is set, the control system is further configured to: control the second time relay and the third time relay to be energized after the backup power switch is turned off, the incoming side of the backup power switch is energized, the substitute switch is closed, and the first time relay is energized for a first preset time.

[0099] Optionally, the control system is also used to control the trip coil of the power switch to stop working using the first hard pressure plate.

[0100] Optionally, the control system is also used to control the closing coil of the backup power switch to stop working using a second hard pressure plate.

[0101] This application provides a low-voltage power supply automatic transfer control system. By setting the conditions for energizing the first time relay to be the working power switch closed, the standby power switch open, and the power bus section energized, it can prevent the standby power supply from continuing to connect to the faulty power bus after the working power switch trips due to a power bus fault. By setting the condition for energizing the second and third time relays to be the normally closed contact of the standby power switch closed, it can ensure that the second and third time relays are no longer energized after the standby power switch is closed, thus ensuring that the automatic transfer of the standby power supply is only activated once. By setting intermediate relays and their contacts, it can prevent the normally open contact of the first voltage relay from opening when the power bus section loses power, thus preventing the first time relay from losing power. Furthermore, because the relays are inexpensive, the low-voltage power supply automatic transfer control system provided in this application can achieve automatic transfer of low-voltage standby power supply at low cost and with high reliability.

[0102] Device Examples

[0103] See Figure 7 This figure is a structural diagram of a control device for automatic switching of a low-voltage power supply according to an embodiment of this application. It is used to automatically control the switching on of the backup power supply in a low-voltage power supply system. The low-voltage power supply system includes: a working power supply, a working power supply switch, a backup power supply, a backup power supply switch, and a power bus section. The working power supply is connected to the power bus section through the working power supply switch, and the backup power supply is connected to the power bus section through the backup power supply switch.

[0104] The device includes:

[0105] The status determination module 701 is used to determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch.

[0106] The first control module 702 is used to control the first time relay to be energized when the working power switch is closed, the backup power switch is open and the power bus section is energized;

[0107] The second control module 703 is used to control the second time relay and the third time relay to be energized after the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not loaded, the power bus section is not energized, and the first time relay is energized for a first preset time.

[0108] The third control module 704 is used to control the working power switch to open by using the trip coil of the working power switch after the working power switch is closed and the second time relay is energized for a second preset time.

[0109] The fourth control module 705 is used to control the backup power switch to close using the closing coil of the backup power switch after the working power switch is turned off and the third time relay is energized for a third preset time.

[0110] The status determination module 701 can be used to determine the load status of the incoming side of the working power switch using a current transformer and a current relay, to determine the energized status of the power bus section using a first voltage relay, and to determine the energized status of the incoming side of the standby power switch using a second voltage relay.

[0111] Optionally, the first control module 702 includes a fifth control module and a sixth control module, wherein the fifth control module is used to control the contacts corresponding to the first voltage relay to close when the first voltage relay determines that the power bus section is energized; the sixth control module is used to control the first time relay to be energized when the working power switch is closed, the backup power switch is open and the contacts corresponding to the first voltage relay are closed.

[0112] Optionally, the second control module 703 includes: a first determining control module, a second determining control module, a third determining control module, and a seventh control module. The first determining control module is used to control the contacts corresponding to the second voltage relay to close when the second voltage relay determines that the incoming side of the backup power switch is energized. The second determining control module is used to control the contacts corresponding to the current transformer and the current relay to close when the current transformer and the current relay determine that the incoming side of the working power switch is not under load. The third determining control module is used to control the contacts corresponding to the first voltage relay to close when the first voltage relay determines that the power bus section is not energized. The seventh control module is used to control the second and third time relays to be energized after the backup power switch is disconnected, the contacts corresponding to the second voltage relay are closed, the contacts corresponding to the current transformer and the current relay are closed, the contacts corresponding to the first voltage relay are closed, and the first time relay is energized for a first preset time.

[0113] Optionally, the device further includes: a first intermediate control module and a second intermediate control module, wherein the first intermediate control module is used to control the intermediate relay to be energized after the backup power switch is turned off and the first time relay is energized for a first preset time; the second intermediate control module is used to control the second time relay and the third time relay to be energized when the backup power switch is turned off, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not loaded, the power bus section is not energized, and the intermediate relay is energized.

[0114] Optionally, the device further includes a switch control module, used to control the second and third time relays to be energized after the backup power switch is turned off, the incoming side of the backup power switch is energized, the alternative switch is closed, and the first time relay is energized for a first preset time.

[0115] Optionally, the device further includes a first hard plate module for controlling the trip coil of the power switch to stop working using the first hard plate.

[0116] Optionally, the device further includes a second hard plate module for controlling the closing coil of the backup power switch to stop working using the second hard plate.

[0117] This application provides a low-voltage power supply automatic transfer switch control device. By setting the conditions for energizing the first time relay to be the working power switch closed, the standby power switch open, and the power bus section energized, it can prevent the standby power supply from continuing to connect to the faulty power bus after the working power switch trips due to a power bus fault. By setting the closing of the normally closed contact corresponding to the standby power switch as the energizing condition for the second and third time relays, it can be ensured that the second and third time relays are no longer energized after the standby power switch is closed, thus ensuring that the automatic transfer of the standby power supply is only activated once. By setting intermediate relays and their contacts, it can be prevented that the normally open contact of the first voltage relay will open when the power bus section loses power, causing the first time relay to lose power. Furthermore, because the relays are inexpensive, the low-voltage power supply automatic transfer switch control device provided in this application can achieve automatic transfer of low-voltage standby power supply in a low-cost and reliable manner.

[0118] It should be noted that the various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, for the device and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the description of the method embodiments. The device and system embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components indicated as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of the solution in this embodiment according to actual needs. Those skilled in the art can understand and implement this without creative effort.

[0119] The above description is merely one specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A control method for automatic transfer switching of low-voltage power supply, characterized in that, This device is used for automatic switching control of backup power in a low-voltage power supply system. The low-voltage power supply system includes: a working power supply, a working power supply switch, a backup power supply, a backup power supply switch, and a power bus section. The working power supply is connected to the power bus section through the working power supply switch, and the backup power supply is connected to the power bus section through the backup power supply switch. The method includes: Determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch; When the working power switch is closed, the backup power switch is open, and the power bus section is energized, the first time relay is energized. After the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the first time relay is energized for a first preset time, the second time relay and the third time relay are energized. After the power switch is closed and the second time relay is energized for a second preset time, the power switch is opened by controlling the trip coil of the power switch to open. After the working power switch is turned off and the third time relay is energized for a third preset time, the backup power switch is controlled to close using the closing coil of the backup power switch. The method further includes: After the backup power switch is turned off and the first time relay is energized for a first preset time, the intermediate relay is energized. When the backup power switch is off, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the intermediate relay is energized, the second time relay and the third time relay are energized.

2. The method according to claim 1, characterized in that, Determining the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch includes: The load status of the incoming line side of the working power switch is determined by using a current transformer and a current relay, the energized status of the power bus section is determined by using a first voltage relay, and the energized status of the incoming line side of the standby power switch is determined by using a second voltage relay.

3. The method according to claim 2, characterized in that, The step of controlling the first time relay to be energized when the working power switch is closed, the standby power switch is open, and the power bus section is energized includes: When the first voltage relay determines that the power bus section is energized, it controls the corresponding contact of the first voltage relay to close. When the working power switch is closed, the backup power switch is open, and the contact corresponding to the first voltage relay is closed, the first time relay is energized.

4. The method according to claim 2, characterized in that, The step of controlling the second and third time relays to energize after the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the first time relay is energized for a first preset time includes: When the second voltage relay determines that the incoming line side of the backup power switch is energized, it controls the corresponding contact of the second voltage relay to close. When the current transformer and the current relay determine that there is no load on the incoming side of the working power switch, control the corresponding contacts of the current transformer and the current relay to close. When the first voltage relay determines that the power bus section is not energized, it controls the corresponding contact of the first voltage relay to close. After the backup power switch is turned off, the contacts corresponding to the second voltage relay are closed, the contacts corresponding to the current transformer and the current relay are closed, the contacts corresponding to the first voltage relay are closed, and the first time relay is energized for a first preset time, the second time relay and the third time relay are energized.

5. The method according to claim 1, characterized in that, The method further includes setting an alternative switch: After the backup power switch is turned off, the incoming side of the backup power switch is energized, the alternative switch is closed, and the first time relay is energized for a first preset time, the second time relay and the third time relay are energized.

6. The method according to claim 1, characterized in that, The method further includes: The trip coil of the power switch is controlled to stop working by using the first hard pressure plate.

7. The method according to claim 1, characterized in that, The method further includes: The closing coil of the backup power switch is stopped by using the second hard pressure plate.

8. A control system for automatic transfer switching of low-voltage power supply, characterized in that, include: The low-voltage power supply system also includes: a first time relay, a second time relay, a third time relay, a trip coil of the working power switch, and a closing coil of the standby power switch; The low-voltage power supply system includes: a working power supply, a working power supply switch, a backup power supply, a backup power supply switch, and a power bus section. The working power supply is connected to the power bus section through the working power supply switch, and the backup power supply is connected to the power bus section through the backup power supply switch. The first time relay is connected to the second time relay, the first time relay is connected to the third time relay, the second time relay is connected to the trip coil of the working power switch, and the third time relay is connected to the closing coil of the standby power switch. The control system is used for: Determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch; When the working power switch is closed, the backup power switch is open, and the power bus section is energized, the first time relay is energized. After the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the first time relay is energized for a first preset time, the second time relay and the third time relay are energized. After the power switch is closed and the second time relay is energized for a second preset time, the power switch is opened by controlling the trip coil of the power switch to open. After the working power switch is turned off and the third time relay is energized for a third preset time, the backup power switch is closed by using the closing coil of the backup power switch.

9. A control device for automatic transfer switching of low-voltage power supply, characterized in that, This device is used for automatic switching control of backup power in a low-voltage power supply system. The low-voltage power supply system includes: a working power supply, a working power supply switch, a backup power supply, a backup power supply switch, and a power bus section. The working power supply is connected to the power bus section through the working power supply switch, and the backup power supply is connected to the power bus section through the backup power supply switch. The device includes: The status determination module is used to determine the load status of the incoming side of the working power switch, the energized status of the power bus section, and the energized status of the incoming side of the standby power switch. The first control module is used to control the first time relay to be energized when the working power switch is closed, the backup power switch is open, and the power bus section is energized. The second control module is used to control the second and third time relays to be energized after the backup power switch is disconnected, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not loaded, the power bus section is not energized, and the first time relay is energized for a first preset time. The third control module is used to control the working power switch to open by using the trip coil of the working power switch after the working power switch is closed and the second time relay is energized for a second preset time. The fourth control module is used to control the backup power switch to close using the closing coil of the backup power switch after the working power switch is turned off and the third time relay is energized for a third preset time. The device further includes: After the backup power switch is turned off and the first time relay is energized for a first preset time, the intermediate relay is energized. When the backup power switch is off, the incoming side of the backup power switch is energized, the incoming side of the working power switch is not under load, the power bus section is not energized, and the intermediate relay is energized, the second time relay and the third time relay are energized.

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