Direct current power supply on-line switching device

Abstract

This utility model belongs to the field of power control technology, specifically relating to an online DC power supply switching device. It comprises two circuits: one is a DC regulated power supply circuit, where the DC regulated power supply's operating power source is connected to the DC regulated power supply itself, and the DC regulated power supply is connected to two parallel diodes with opposite polarities, which are then connected to the regulated power supply's output adjustment display screen; the other circuit is a temporary power supply monitoring circuit, where the temporary power supply is connected to the input voltage / current display screen, and the input voltage / current display screen, isolating switch, and output voltage / current display screen are connected in series. This utility model enables safer and more efficient on-site DC power supply switching without power interruption, effectively improving personnel efficiency, equipment / personnel safety, and reducing human error. This ensures the safety of nuclear power plant personnel and the normal operation of equipment, and has significant application value in this field.

Description

Technical Field

[0001] This utility model belongs to the field of power control technology, specifically relating to an online DC power supply switching device. Background Technology

[0002] During major overhauls, some loads on medium-voltage switchgear need to continue operating. To ensure the safety of the medium-voltage switchgear operation, reliable power supply to the medium-voltage busbar's DC auxiliary power supply is essential. The original design did not consider the special condition where the auxiliary DC power supply to the medium-voltage switchgear needs to be shut down for maintenance, while the switchgear still needs to operate normally. This results in the medium-voltage switchgear losing its DC auxiliary power supply when the upstream DC switchgear is under maintenance. If the DC system is directly shut down, but the medium-voltage switchgear remains operational, a fault downstream of the switchgear will occur, leaving it without protection and triggering the next higher level of protection, potentially expanding the scope of the accident. Furthermore, the operating conditions of electrical equipment are complex during major overhauls; a sudden power loss could lead to unexpected equipment responses, causing damage or even personal injury.

[0003] To avoid loss of DC power during busbar operation, a switching scheme is currently adopted, where the main DC power supply and temporary DC power supply are switched on and off sequentially to ensure uninterrupted power supply to the medium-voltage protection devices. The temporary power supply voltage is not adjustable, so a DC regulated power supply combined with diodes is used for transition switching. During normal operation, the DC load consists only of the protection devices and relays, with an operating current of approximately 1A. Therefore, diodes with a rated current of not less than 3A are selected to meet the uninterrupted switching requirements. This scheme involves the disconnection and reconnection of multiple circuits, and the steps are relatively complex, requiring a high level of skill from the personnel. Utility Model Content

[0004] The purpose of this utility model is to provide an online DC power switching device that is easy to operate, can effectively improve personnel efficiency and equipment / personnel safety, reduce human error, and ensure that the small busbar will not lose power during power switching, thus ensuring safe and reliable operation.

[0005] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0006] A DC power supply online switching device is provided, comprising two circuits: one is a DC regulated power supply circuit, in which the DC regulated power supply working power supply is connected to the DC regulated power supply, and the DC regulated power supply is connected to two diodes in parallel with opposite polarities, and the two diodes are connected to the output adjustment display screen of the regulated power supply; the other circuit is a temporary power supply monitoring circuit, in which the temporary power supply is connected to the input voltage / current display screen, and the input voltage / current display screen, the isolating switch, and the output voltage / current display screen are connected in series.

[0007] The DC regulated power supply is connected to the DC regulated power supply via the quick-connect port on the input side of the DC regulated circuit on the device housing.

[0008] The DC regulated power supply has a rated voltage of 250V and a rated current of 6A.

[0009] The device housing is made of galvanized steel sheet and has an insulating coating.

[0010] The regulated power supply output adjustment display screen is connected to the external circuit through the quick-connect port on the DC regulated circuit output side of the device housing.

[0011] The temporary power supply is connected to the input voltage / current display screen via the quick-connect port on the temporary power circuit input side of the device housing.

[0012] The output voltage / current display is connected to an external circuit via a quick-connect port on the output side of the temporary power circuit on the device housing.

[0013] The beneficial effects achieved by this utility model are as follows:

[0014] This invention enables safer and more efficient on-site DC power switching without interruption, effectively improving personnel efficiency, equipment / personnel safety, and reducing human error. This ensures the safety of nuclear power plant personnel and the normal operation of equipment, and has significant application value in this field. Attached Figure Description

[0015] Figure 1 This is a structural diagram of a DC power supply online switching device. Detailed Implementation

[0016] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0017] A DC power supply online switching device comprises two circuits: one is a DC regulated power supply circuit, in which the DC regulated power supply's operating power supply is connected to the DC regulated power supply, which is connected to two diodes in parallel with opposite polarities. These two diodes are connected to the regulated power supply's output adjustment display screen. The other circuit is a temporary power supply monitoring circuit, in which the temporary power supply is connected to the input voltage / current display screen, and the input voltage / current display screen, isolating switch, and output voltage / current display screen are connected in series. The DC regulated power supply's operating power supply is connected to the DC regulated power supply via a quick-connect port on the DC regulated circuit input side of the device housing. The DC regulated power supply has a rated voltage of 250V and a rated current of 6A. The device housing is made of galvanized steel sheet with an insulating coating. The regulated power supply's output adjustment display screen is connected to an external circuit via a quick-connect port on the DC regulated circuit output side of the device housing. The temporary power supply is connected to the input voltage / current display screen via a quick-connect port on the temporary power supply circuit input side of the device housing. The output voltage / current display screen is connected to an external circuit via a quick-connect port on the temporary power supply circuit output side of the device housing.

[0018] The tool housing is made of galvanized steel sheet with an insulating coating. It has two circuits. One circuit is a DC voltage regulator circuit, equipped with a 250V rated voltage, 6A rated current DC voltage regulator for flexible DC voltage adjustment. Meters on the same circuit allow on-site personnel to easily monitor the DC voltage and current output of this circuit. The other circuit is a temporary power monitoring circuit. This circuit is mainly used for disconnecting the circuit when it is not energized. Disconnection under load is achieved through an air switch on the temporary power supply side. Both ends of the isolating switch are equipped with a multi-function meter to monitor the voltage and current across the isolating switch, allowing personnel to adjust the output voltage of the DC voltage regulator by monitoring the temporary power supply circuit voltage.

[0019] A dedicated tool for online DC power switching is disclosed, comprising two circuits. One circuit connects to a DC regulated power supply via a quick-connect port on the input side of the device housing. The DC regulated power supply is connected to a set of diodes via cables, which in turn are connected to the output adjustment display screen via cables. This display screen is then connected to the quick-connect port on the output side of the DC regulated power supply on the device housing for connection to an external circuit. The other branch, a temporary power supply, is connected to the quick-connect port on the input side of the temporary power supply circuit on the device housing via cables. Internally, an input voltage / current display screen, an isolating switch, and an output voltage / current display screen are connected in series via cables. The output voltage / current display screen is connected in series via a set of cables to the quick-connect port on the output side of the temporary power supply circuit on the device housing for connection to an external circuit.

[0020] The specific operation method for switching from the main DC power supply to the temporary power supply is as follows: Initially, the main power supply circuit supplies power to the downstream load; open fuses B+ and B-, and terminate output 1 of switching device 1 with the lower port of the fuse; adjust the voltage of the regulated power supply circuit B to be 1V lower than that of the main DC power supply circuit; close fuses B+ and B- to form a circulating current in circuits A and B, with circuit B not outputting current to carry the load; disconnect fuses A+ and A- in the main circuit A; switch to circuit B to carry the load; open fuses C+ and C-, and terminate output 3 of the switching device with the lower port of the fuse; adjust the output voltage of the switching device to be 1V lower than that of the temporary power supply circuit; close fuses C+ and C- to complete the switching, ensuring output current; open fuses B+ and B-. Note: The above method achieves uninterrupted switching of the DC power supply from the main DC power supply circuit to the temporary power supply.

[0021] Switching from temporary power supply to permanent DC power supply: Initially, the temporary power supply circuit supplies power to the downstream load; measure the voltage of the DC regulated power supply circuit and adjust the DC regulated power supply voltage to be 1V lower than the temporary power supply circuit; disconnect fuses C+ and C- to switch to the DC regulated power supply for load operation; measure the voltage of circuit A and adjust the DC regulated power supply voltage to be 1V lower than circuit A; close fuses A+ and A- to complete the switching. Note: The above method achieves uninterrupted switching of the DC power supply from temporary power supply to permanent DC power supply circuit.

Claims

1. A DC power supply online switching device, characterized in that: Two circuits are set up in total; one is a DC regulated power supply circuit: the working power supply of the DC regulated power supply is connected to the DC regulated power supply, the DC regulated power supply is connected to two diodes in parallel with opposite polarities, and the two diodes are connected to the output adjustment display screen of the regulated power supply; the other circuit is a temporary power supply monitoring circuit: the temporary power supply is connected to the input voltage / current display screen, and the input voltage / current display screen, the isolating switch, and the output voltage / current display screen are connected in series.

2. The DC power supply online switching device according to claim 1, characterized in that: The DC regulated power supply is connected to the DC regulated power supply via the quick-connect port on the input side of the DC regulated circuit on the device housing.

3. The DC power supply online switching device according to claim 1, characterized in that: The DC regulated power supply has a rated voltage of 250V and a rated current of 6A.

4. The DC power supply online switching device according to claim 1, characterized in that: The device housing is made of galvanized steel sheet and has an insulating coating.

5. The DC power supply online switching device according to claim 1, characterized in that: The regulated power supply output adjustment display screen is connected to the external circuit through the quick-connect port on the DC regulated circuit output side of the device housing.

6. The DC power supply online switching device according to claim 1, characterized in that: The temporary power supply is connected to the input voltage / current display screen via the quick-connect port on the temporary power circuit input side of the device housing.

7. The DC power supply online switching device according to claim 1, characterized in that: The output voltage / current display is connected to an external circuit via a quick-connect port on the output side of the temporary power circuit on the device housing.

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