A voltage loss compensation device and DC power supply system

Abstract

The present invention discloses a voltage loss compensation device and a DC power supply system, which relate to the field of power distribution equipment. The voltage loss compensation device includes a conversion module, a monitoring device and a control switch. The conversion module is arranged between the power bus bars at both ends, allowing current to flow bidirectionally between the power bus bars. The monitoring device is used to collect system operation data, monitor the voltage status of the main power supply and the backup power supply in real time, and control the switch. The conversion module is connected in parallel with the control switch. The conversion module is controlled according to the data collected by the monitoring device. Through the conversion module, no on-site operation is required. The network verifies and monitors the status, performance and remaining capacity of two groups of batteries on site. In the past, the battery capacity verification required personnel to perform reverse turn operations on site. Now, a switching device is provided to trigger the switching action without the need for personnel to be present. This function ensures the time and labor costs of the operation and maintenance personnel, and can obtain battery information in a timely manner, optimize the use and maintenance of the battery, and improve the reliability of the system.

Description

Technical Field

[0001] The present invention relates to the technical field of power distribution equipment, in particular to a voltage loss compensation device and a direct current power supply system. Background Art

[0002] In a dual-configuration DC system substation, when a DC system power supply failure occurs and there is no one on duty and the alarm is not handled in time, it is easy to cause the battery pack to fail to charge normally for a long time and become depleted, or even lose all capacity, affecting the stable operation of the power grid.

[0003] At present, most substations are unmanned. When a DC power supply line of the DC system fails, it is difficult for operators and professionals to arrive in time, and there is a situation where it is impossible to switch to another DC power supply line in time; if the charging device fails or is set incorrectly, it is easy to cause the battery pack to fail to charge normally for a long time and lose capacity, or even lose all capacity, affecting the stable operation of the power grid when the DC bus voltage difference and other conditions do not meet the requirements, when operating the bus tie switch, it may cause a huge impact current, threatening the personal safety of the operator and causing damage to the battery.

[0004] To ensure the safe operation of the power system, the control and protection equipment of the substation are all powered by DC power. The DC system uses AC / DC as the main power supply, and the battery is designed as a backup power supply. The DC system is also equipped with two sets of DC systems as backup during design. However, the bus tie switches of the two sections of the DC system that serve as backup for each other are designed in manual mode. The bus tie switches are only closed when the DC system power supply is being repaired, and the two independent DC systems can serve as backup for each other. When an accident occurs simultaneously in the battery and charger system of a certain section of the DC system, the DC system loses power, and the backup systems that serve as backup for each other cannot play a backup role. Therefore, an intelligent bus tie system with the characteristics of automatic input, high voltage isolation, and short-circuit protection is required. Summary of the invention

[0005] In view of the problems existing in the above-mentioned pressure loss compensation device, the present invention is proposed.

[0006] Therefore, the problem to be solved by the present invention is how to prevent the backup system from failing to play a backup role.

[0007] To solve the above technical problems, the present invention provides the following technical solutions: a voltage loss compensation device, comprising: a conversion module, which is arranged between the two end power buses and allows current to flow bidirectionally between the power buses; a monitoring device, which is used to collect system operation data; a control switch, the conversion module is connected in parallel with the control switch; and the conversion module is controlled according to the data collected by the monitoring device.

[0008] As a preferred solution of the voltage loss compensation device of the present invention, the conversion module is a dual-port structure, which is respectively connected to a segment DC bus and a segment DC bus.

[0009] As a preferred solution of the voltage loss compensation device of the present invention, the DC bus segment and the DC bus segment are connected to the first battery group and the second battery group respectively.

[0010] As a preferred solution of the voltage loss compensation device of the present invention, the first battery group and the second battery group serve as backup power sources for each other.

[0011] As a preferred solution of the voltage loss compensation device described in the present invention, wherein: an incoming line connector is arranged between the first battery group and the segment DC bus; the second battery group and the segment DC bus are also agreed to be provided with the incoming line connector; the incoming line connector is connected in parallel with the corresponding battery group.

[0012] As a preferred solution of the voltage loss compensation device of the present invention, the incoming line contact includes a diode connected in series with the corresponding battery pack and a normally closed switch connected in series with the diode.

[0013] As a preferred solution of the voltage loss compensation device of the present invention, the incoming line contact also includes a normally open switch connected in series with the conversion module.

[0014] As a preferred solution of the voltage loss compensation device of the present invention, two ends of the conversion module are respectively connected to a group of filter capacitors.

[0015] Another object of the present invention is to provide a DC power supply system, which comprises: when both sections of the DC bus are normal, the two DC ports of the conversion module are in the input state; when the voltage of any of the DC bus is abnormal, the corresponding port of the conversion module is automatically converted to the output state, and the power of the other section of the DC bus is transmitted to the fault section bus, so as to ensure uninterrupted power supply of the fault section bus

[0016] As a preferred solution of the DC power supply system of the present invention, the conversion module is a voltage-stabilized power supply with two DC ports electrically isolated, and is not a step-down device in the form of a chopper.

[0017] The beneficial effects of the present invention are as follows: 1. Automatic switching of the main power supply and the standby power supply can be realized without manual intervention, thereby improving the reliability and stability of the power system;

[0018] 2. The voltage loss detection module can monitor the voltage of the main power supply in real time, and the device can switch in a very short time to ensure the continuity of load power supply.

[0019] 3. During the switching process, the device will ensure electrical isolation between the main power supply and the backup power supply to prevent damage to electrical equipment.

[0020] 4. After receiving the signal, the switching control module will disconnect the main power supply and the backup power supply through the electrical isolation device at the moment of switching to prevent them from directly contacting each other during the transition. The isolation module can ensure efficient isolation even with a difference of hundreds of volts, thereby ensuring the safety of the device and the load.

[0021] 5. The device usually also has a short-circuit protection function, which can quickly cut off the power supply when a short circuit occurs to prevent the accident from expanding.

[0022] 6. The device's current detector monitors the current of the main and standby power supplies in real time. When it detects that the current exceeds the set safety threshold, it quickly issues a cut-off command. After receiving the command, the protective relay or solid-state switch immediately performs the cut-off operation to prevent further short-circuit damage.

[0023] 7. Through the application of intelligent busbar bidirectional voltage loss compensation device, the problem of failure of DC system backup power supply can be effectively solved, and the reliability and safety of the power system can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. Among them:

[0025] Figure 1 It is the structural diagram of the voltage loss compensation device and the DC power supply system.

[0026] Figure 2 This is the circuit diagram of the voltage loss compensation device. DETAILED DESCRIPTION

[0027] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0028] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0029] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it an embodiment that is mutually exclusive with other embodiments, either individually or selectively.

[0030] Example 1

[0031] Reference Figure 1 and Figure 2 , which is the first embodiment of the present invention, provides a voltage loss compensation device, which includes a conversion module 100, a monitoring device 200 and a control switch 300. According to the signal of the monitoring device 200, the state of the main power supply or the backup power supply is intelligently judged, and automatic power supply switching is performed to ensure uninterrupted power supply.

[0032] Specifically, the conversion module 100 is disposed between the power bus bars at both ends, allowing current to flow bidirectionally between the power bus bars.

[0033] Preferably, the monitoring device 200 is used to collect system operation data and monitor the voltage status of the main power supply and the backup power supply in real time. When a failure of the main power supply is detected, a switching signal is immediately triggered.

[0034] Preferably, the control switch 300, the conversion module 100 is connected in parallel with the control switch 300;

[0035] The conversion module 100 is controlled according to the data collected by the monitoring device 200 .

[0036] When in use, the conversion module 100 is used to ensure that no on-site operation is required. The network verifies and monitors the status, performance and remaining capacity of the two groups of batteries on site. In the past, battery capacity verification required personnel to perform reverse operations on site. Now, a switching device is provided to trigger the switching action without the need for personnel to be present. This function saves the time and labor costs of operation and maintenance personnel, and can obtain battery information in a timely manner, optimize battery use and maintenance, and improve system reliability.

[0037] Example 2

[0038] Reference Figure 2 , which is the second embodiment of the present invention, and this embodiment is based on the previous embodiment.

[0039] Specifically, the conversion module 100 is a dual-port structure, which is connected to the I-section DC bus and the II-section DC bus respectively.

[0040] Preferably, the DC bus section I and the DC bus section II are connected to the first battery pack and the second battery pack respectively.

[0041] Preferably, the first battery pack and the second battery pack serve as backup power sources for each other.

[0042] Preferably, an incoming line connection piece 400 is provided between the first battery pack and the I-section DC bus;

[0043] The second battery pack and the II section DC busbar are also provided with an incoming line contact 400;

[0044] The incoming line connection piece 400 is connected in parallel with the corresponding battery pack.

[0045] Preferably, the incoming line contact 400 includes a diode connected in series with the corresponding battery pack and a normally closed switch connected in series with the diode.

[0046] Preferably, the incoming line contact 400 further includes a normally open switch connected in series with the conversion module 100 .

[0047] Preferably, two ends of the conversion module 100 are each connected to a group of filter capacitors.

[0048] When in use, the two DC ports of the conversion module 100 are electrically isolated. When both sections of the DC bus are normal, the two DC ports of the conversion module 100 are in the input state. When the voltage of any bus is abnormal, the corresponding port of the conversion module 100 automatically switches to the output state, and transmits the power of the other section of the bus to the faulty section of the bus, ensuring uninterrupted power supply to the faulty section of the bus. Each port of the conversion module 100 contains a filter capacitor, which can store energy and prevent the output voltage from dropping when the output state is switched;

[0049] The conversion module 100 solution has a fast response speed because there is no closing and opening operation of the bus tie switch;

[0050] Because the output of the conversion module 100 has a reliable current limiting protection characteristic, the normal bus section will not be overloaded due to the overload of the faulty bus section. Therefore, the output state conversion of the conversion module 100 does not need to consider the size of the load current, and only needs to detect the bus voltage. The control logic is simple and reliable. The conversion module 100 has a short-term overload capacity of 200% and can meet the requirements of impact loads. It should be emphasized here that the conversion module 100 is a voltage-stabilized power supply with two DC ports electrically isolated, not a step-down device in the form of a chopper.

[0051] Example 3

[0052] Reference Figure 2 , which is the third embodiment of the present invention, and is based on the first two embodiments.

[0053] Specifically, when both sections of the DC bus are normal, the two DC ports of the conversion module 100 are in the input state. When the voltage of any DC bus is abnormal, the corresponding port of the conversion module 100 is automatically converted to the output state, and the power of the other section of the DC bus is transmitted to the faulty section bus, thereby ensuring uninterrupted power supply to the faulty section bus.

[0054] Preferably, the conversion module 100 is a voltage-stabilized power supply with two DC ports electrically isolated, and is not a voltage-reducing device in the form of a chopper.

[0055] When in use, the state of the main power supply or the backup power supply is intelligently determined based on the signal from the monitoring device 100, and automatic power switching is performed to ensure uninterrupted power supply.

[0056] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A pressure loss compensation device, characterized in that: include, A conversion module (100) is arranged between the power bus bars at both ends, allowing current to flow bidirectionally between the power bus bars; A monitoring device (200) for collecting system operation data; A control switch (300), the conversion module (100) being connected in parallel with the control switch (300); The conversion module (100) is controlled according to the data collected by the monitoring device (200).

2. The pressure loss compensation device according to claim 1, characterized in that: The conversion module (100) is a dual-port structure, which is respectively connected to a section I DC bus and a section II DC bus.

3. The pressure loss compensation device according to claim 2, characterized in that: The section I DC bus and the section II DC bus are connected to the first battery pack and the second battery pack respectively.

4. The pressure loss compensation device according to claim 3, characterized in that: The first battery pack and the second battery pack serve as backup power sources for each other.

5. The pressure loss compensation device according to claim 4, characterized in that: An incoming line connection piece (400) is provided between the first battery pack and the I-section DC busbar; The second battery pack and the section II DC busbar are also provided with the incoming line connection piece (400); The incoming line connection piece (400) is connected in parallel with the corresponding battery pack.

6. The pressure loss compensation device according to claim 5, characterized in that: The incoming line contact (400) comprises a diode connected in series with the corresponding battery pack and a normally closed switch connected in series with the diode.

7. The pressure loss compensation device according to claim 6, characterized in that: The incoming line contact (400) further comprises a normally open switch connected in series with the conversion module (100).

8. The pressure loss compensation device according to claim 7, characterized in that: Two ends of the conversion module (100) are respectively connected to a group of filter capacitors.

9. A DC power supply system, comprising the voltage loss compensation device according to claims 1 to 8, comprising: When both sections of the DC bus are normal, the two DC ports of the conversion module (100) are in an input state; when the voltage of any one of the DC buses is abnormal, the corresponding port of the conversion module (100) is automatically converted to an output state, and the electric energy of the other section of the DC bus is transmitted to the faulty section bus, thereby ensuring uninterrupted power supply to the faulty section bus.

10. The pressure loss compensation device according to claim 9, characterized in that: The conversion module (100) is a voltage-stabilized power supply with two DC ports electrically isolated, and is not a voltage-reducing device in the form of a chopper.

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