Direct-current power supply bus voltage loss prevention device

Abstract

The invention discloses a direct-current power supply bus voltage loss prevention device which comprises a main power supply circuit, a standby power supply circuit and an emergency power supply circuit. The main power supply circuit comprises a power input circuit, a first rectifier, a direct current power supply interface and a direct current bus, a first connecting circuit is connected between the output end of the first rectifier and the input end of the direct current power supply interface, and a K1 relay is installed on the first connecting circuit; the standby power supply circuit comprises a charging circuit, a charger and a battery pack, a second connecting circuit is connected between the output end of the battery pack and the input end of the direct-current power supply interface, and a K2 relay is installed on the second connecting circuit; the emergency power supply circuit comprises a generator and a second rectifier, a third connecting circuit is connected between the output end of the second rectifier and the input end of the direct current power supply interface, and a K3 relay is installed on the third connecting circuit; the device can timely recover the power supply of the DC bus when the DC bus loses voltage, ensures the normal operation of the transformer substation, and strives for time for troubleshooting.

Description

Technical Field

[0001] This invention relates to the field of power equipment technology, and in particular to a DC power bus anti-voltage device. Background Technology

[0002] DC power supply systems are essential power equipment in substations. Control, protection, energy storage, interlocking, signal circuits, and emergency lighting of primary power equipment are all powered by DC. Currently, most substation DC systems use station AC power rectified by a rectifier circuit to supply these circuits. When an accident occurs within the substation causing the station AC power supply to become unavailable, it can lead to DC bus voltage loss, affecting the normal operation of the substation. Summary of the Invention

[0003] The purpose of this invention is to provide a DC power bus undervoltage protection device that can restore the power supply to the DC bus in a timely manner when the DC bus is undervoltage, ensuring the normal operation of the substation and buying time for fault diagnosis.

[0004] To achieve the above objectives, the present invention adopts the following technical solution: a DC power bus undervoltage protection device, comprising a main power supply line, a backup power supply line, an emergency power supply line, and a control module; the main power supply line includes a power input line, a first rectifier, a DC power supply interface, and a DC bus; the power input line is AC and connected to the input terminal of the first rectifier; a first connection line is connected between the output terminal of the first rectifier and the input terminal of the DC power supply interface, and a K1 relay is installed on the first connection line; the DC bus is connected to the output terminal of the DC power supply interface; the backup power supply line includes a charging line, a charger, and a battery pack; the charging line is connected to the input terminal of the charger; the output terminal of the charger is electrically connected to the input terminal of the battery pack; a second connection line is connected between the output terminal of the battery pack and the input terminal of the DC power supply interface, and a K2 relay is installed on the second connection line; the emergency power supply line includes a generator and a second rectifier; the generator is electrically connected to the input terminal of the second rectifier; a third connection line is connected between the output terminal of the second rectifier and the input terminal of the DC power supply interface, and a K3 relay is installed on the third connection line; the first rectifier, the battery pack, and the DC power supply interface are all electrically connected to the control module.

[0005] Optionally, the battery pack contains two sets of lithium batteries. The input terminal of one set of lithium batteries is electrically connected to the charger and is equipped with a K4 relay, and the output terminal of the lithium battery is electrically connected to the first connection line and is also equipped with a K4 relay. The input terminal of the other set of lithium batteries is electrically connected to the charger and is equipped with a K5 relay, and the output terminal of the lithium battery is electrically connected to the first connection line and is also equipped with a K5 relay.

[0006] Optionally, the battery pack is equipped with a charge / discharge test module.

[0007] Optionally, the generator is equipped with an emergency power supply test module.

[0008] Optionally, a diesel generator may be used.

[0009] The DC power bus undervoltage protection device of the present invention has the following advantages: (1) A redundant design is adopted, with three modes for power supply to the DC bus. The three modes are independent of each other. When the main power supply line has a problem, the backup power supply line will intervene. When the backup power supply line also has a problem, the emergency power supply line will intervene to ensure the normal operation of the DC bus.

[0010] (2) Two sets of lithium batteries can improve the stability of the backup power supply line.

[0011] (3) The charging and discharging test module and the emergency power supply test module can detect whether the backup power supply line and the emergency power supply line can operate normally. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0013] The invention will now be further described with reference to the accompanying drawings.

[0014] The terms “first” and “second” are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated.

[0015] like Figure 1 As shown, a DC power bus undervoltage protection device includes a main power supply line 1, a backup power supply line 2, an emergency power supply line 3, and a control module 4. The main power supply line 1 includes a power input line 5, a first rectifier 6, a DC power supply interface 7, and a DC bus 8. The power input line 5 is AC and is connected to the input terminal of the first rectifier 6. A first connection line 9 is connected between the output terminal of the first rectifier 6 and the input terminal of the DC power supply interface 7. A K1 relay is installed on the first connection line 9. The DC bus 8 is connected to the output terminal of the DC power supply interface 7.

[0016] The backup power supply line 2 includes a charging line 10, a charger 11, and a battery pack 12. The charging line 10 is connected to the input terminal of the charger 11 and uses an AC power source different from the main power supply line 1. The output terminal of the charger 11 is electrically connected to the input terminal of the battery pack 12. A second connection line 13 connects the output terminal of the battery pack 12 to the input terminal of the DC power supply interface 7, and a K2 relay is installed on the second connection line 13. The battery pack 12 contains two sets of lithium batteries. The input terminal of one set of lithium batteries is electrically connected to the charger 11 and is equipped with a K4 relay, and the output terminal of the lithium battery is electrically connected to the first connection line 9 and is also equipped with a K4 relay. The input terminal of the other set of lithium batteries is electrically connected to the charger 11 and is equipped with a K5 relay, and the output terminal of the lithium battery is electrically connected to the first connection line 9 and is also equipped with a K5 relay. The two sets of lithium batteries are switched periodically, one as a backup and the other as a primary battery. The battery pack 12 is equipped with a charge / discharge test module 14 to perform charge / discharge operations on the lithium batteries to ensure their normal operation and prevent malfunctions caused by prolonged periods of inactivity.

[0017] Emergency power supply line 3 includes a generator 15 and a second rectifier 16. The generator 15 is electrically connected to the input terminal of the second rectifier 16. A third connection line 17 connects the output terminal of the second rectifier 16 to the input terminal of the DC power supply interface 7. A K3 relay is installed on the third connection line 17. The generator 15 is a diesel generator, which has high stability. An emergency power supply test module 18 is correspondingly set up for the generator 15 to periodically start the diesel generator to perform power supply operation and ensure that the generator 15 can operate normally.

[0018] The first rectifier 6, battery pack 12, and DC power supply interface 7 are all electrically connected to the control module 4. They detect the voltage of the main power supply line 1 and the backup power supply line 2, and determine the operating status of the DC bus 8 based on the voltage readings. During normal operation, the main power supply line 1 provides power, relay K1 is closed, other relays are open, and one lithium battery remains charged. The AC power from the main power supply line 1, after passing through the first rectifier 6, supplies DC power to the DC bus 8. When the control module 4 detects a voltage drop in the DC bus 8, relay K1 immediately closes, connecting battery pack 12 to supply power to the DC bus 8. When battery pack 12 also fails to operate normally, generator 15 is started, and the power is directly supplied to the DC bus 8 after rectification by the second rectifier 16. Backup power supply line 2 and emergency power supply line 3 are temporary power supply solutions and cannot operate stably for extended periods. They provide time for troubleshooting and equipment maintenance on the main power supply line 1.

[0019] The embodiments described above are merely some, not all, embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the protection scope of the present invention.

Claims

1. A DC power bus undervoltage protection device, characterized in that: The system includes a main power supply line, a backup power supply line, an emergency power supply line, and a control module. The main power supply line includes a power input line, a first rectifier, a DC power supply interface, and a DC bus. The power input line is AC and connected to the input terminal of the first rectifier. A first connection line connects the output terminal of the first rectifier to the input terminal of the DC power supply interface, and a K1 relay is installed on the first connection line. The DC bus is connected to the output terminal of the DC power supply interface. The backup power supply line includes a charging line, a charger, and a battery pack. The charging line is connected to the input terminal of the charger. The output terminal of the charger is electrically connected to the input terminal of the battery pack. A second connection line connects the output terminal of the battery pack to the input terminal of the DC power supply interface, and a K2 relay is installed on the second connection line. The emergency power supply line includes a generator and a second rectifier. The generator is electrically connected to the input terminal of the second rectifier. A third connection line connects the output terminal of the second rectifier to the input terminal of the DC power supply interface, and a K3 relay is installed on the third connection line. The first rectifier, the battery pack, and the DC power supply interface are all electrically connected to the control module.

2. The DC power bus undervoltage protection device as described in claim 1, characterized in that: The battery pack contains two sets of lithium batteries. The input terminal of one set of lithium batteries is electrically connected to the charger and is equipped with a K4 relay. The output terminal of the lithium battery is electrically connected to the first connection line and is also equipped with a K4 relay. The input terminal of the other set of lithium batteries is electrically connected to the charger and is equipped with a K5 relay. The output terminal of the lithium battery is electrically connected to the first connection line and is also equipped with a K5 relay.

3. The DC power bus undervoltage protection device as described in claim 2, characterized in that: The battery pack is equipped with a charge and discharge test module.

4. The DC power bus undervoltage protection device as described in claim 1, characterized in that: The generator is equipped with an emergency power supply test module.

5. The DC power bus undervoltage protection device as described in claim 1, characterized in that: The generator is a diesel generator.

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