Direct current bus power loss alarm system

Abstract

The utility model provides a DC bus power-loss alarm system, which comprises a relay module, an alarm module and a storage battery pack, the alarm module comprises a normally closed contact unit, a self-checking contact unit and an alarm unit; one end of the relay module is connected with the positive electrode of the direct-current bus, and the other end of the relay module is connected with the negative electrode of the direct-current bus; one end of the self-checking contact unit is connected with the positive electrode of a direct current bus, and the other end of the self-checking contact unit is connected with the normally-closed contact unit and the alarm unit. The other end of the alarm unit is connected with the cathode of the DC bus. The direct current bus is connected with the storage battery pack; and the alarm module is arranged between the relay module and the storage battery pack. The utility model solves the problem of low safety of the direct current system caused by the fact that the power loss of the direct current system cannot be found in time in the prior art. According to the utility model, the safety of the DC system can be improved.

Description

Technical Field

[0001] The utility model relates to the field of direct current bus fault elimination, in particular to a direct current bus power failure alarm system. Background Art

[0002] The power supply for the power plant's relay protection device and the backup power supply for important power loads are both taken from the DC bus. If the DC bus loses power, the equipment on the DC bus will stop working. In serious cases, personal injury, equipment or power grid accidents may occur due to the loss of system protection. Therefore, ensuring that the DC bus does not lose power is an important condition for the normal operation of the power system.

[0003] At present, the DC bus usually has two power sources: a DC battery and an AC charger. The AC charger is taken from the system AC power supply, and supplies power to the DC bus after rectification. It can also be used as a charging power source for the battery. When the AC power supply is normal, the AC power supply provides power to the DC bus after conversion; when the AC power supply fails, the battery pack in the DC operating power supply system provides power to the DC bus. Under normal circumstances, due to the dual protection of the battery and the charger, it is difficult for the DC bus to lose power. However, if the DC bus loses power, the relay protection device in the relay protection room loses power, and the alarm power supply and protection power supply are also lost. On-site operators can only judge the bus power failure by observing the power-on status of the relay protection device or the detection device. Due to the lack of sound and light alarms, operators are prone to misjudgment, and it is difficult for on-site patrol personnel to find the cause of the fault in time, which prolongs the time for accident handling, causing the power system to lose protection and deteriorate safety. Utility Model Content

[0004] Based on the above problems, the utility model proposes a DC bus power failure alarm system to solve the problem that the prior art cannot detect the power failure of the DC system in time, resulting in low safety of the DC system.

[0005] To achieve the above-mentioned purpose, the embodiment of the utility model provides a DC bus power failure alarm system, comprising: a relay module, an alarm module and a battery pack;

[0006] The alarm module comprises: a normally closed contact unit, a self-test contact unit and an alarm unit;

[0007] One end of the relay module is connected to the positive pole of the DC bus, and the other end of the relay module is connected to the negative pole of the DC bus;

[0008] One end of the self-test contact unit is connected to the positive pole of the DC bus, and the other end of the self-test contact unit is connected to the normally closed contact unit and the alarm unit respectively;

[0009] The other end of the alarm unit is connected to the negative pole of the DC bus;

[0010] The DC bus is connected to the battery pack;

[0011] The alarm module is arranged between the relay module and the battery pack.

[0012] Furthermore, the relay module includes: a first relay and a second relay

[0013] One end of the first relay is connected to the positive pole of the DC bus, and the other end of the first relay is connected to the negative pole of the DC bus;

[0014] One end of the second relay is connected to the positive pole of the DC bus, and the other end of the second relay is connected to the negative pole of the DC bus.

[0015] Further, the self-checking contact unit includes: a normally open contact and a normally closed self-locking contact;

[0016] One end of the normally closed self-locking contact is connected to the positive pole of the DC bus, and the other end of the normally closed self-locking contact is respectively connected to the normally closed contact unit and the normally open contact;

[0017] The normally open contact is connected in parallel with the normally closed contact unit.

[0018] Further, the normally closed contact unit includes: a first normally closed relay contact and a second normally closed relay contact;

[0019] The first normally closed relay contact and the second normally closed relay contact are connected in parallel;

[0020] One end of the first normally closed relay contact and one end of the second normally closed relay contact are connected to the normally closed self-locking contact, and the other end of the first normally closed relay contact and the other end of the second normally closed relay contact are connected to the alarm unit.

[0021] Further, the alarm unit includes: a buzzer or an audible and visual alarm device;

[0022] The alarm unit is connected to the self-test contact unit and the battery pack respectively.

[0023] Furthermore, a circuit breaker is provided between the positive and negative poles of the DC bus; the circuit breaker is used to cut off the circuit current.

[0024] Furthermore, the battery pack is a backup power source, and the battery pack is composed of a number of battery cells connected in series or in parallel.

[0025] Beneficial effects:

[0026] (1) The embodiment of the utility model provides a DC bus power failure alarm system, which adds an alarm unit as an alarm reminder for DC bus voltage loss, and improves the safety of the DC system through the alarm reminder of the alarm module;

[0027] (2) The embodiment of the utility model provides a DC bus power failure alarm system, which adds a battery pack as the power source of the alarm unit to prevent the alarm unit from being unable to provide an alarm reminder in time when the DC bus loses voltage, thereby improving the safety of the DC system;

[0028] (3) The embodiment of the utility model provides a DC bus power failure alarm system, wherein the relay module is composed of a first relay and a second relay, and the first relay and the second relay are backup for each other; this prevents the problem that the DC system power failure alarm cannot be achieved when a certain relay is damaged, further ensures the alarm reminder function and improves the safety of the DC system;

[0029] (4) The embodiment of the utility model proposes a DC bus power failure alarm system, which adds a self-test switch unit as a fault self-discharging circuit structure, thereby determining whether the alarm unit is damaged, thereby ensuring the normal operation of the alarm unit and improving the safety performance of the DC system. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 A schematic diagram of the module structure of a DC bus power failure alarm system provided by a certain embodiment of the utility model;

[0031] Figure 2 A schematic diagram of the structure of a relay module of a DC bus power failure alarm system provided by a certain embodiment of the utility model;

[0032] Figure 3 A schematic diagram of the structure of a self-checking contact unit of a DC bus power failure alarm system provided by a certain embodiment of the utility model;

[0033] Figure 4 A schematic diagram of the structure of a normally closed contact unit of a DC bus power failure alarm system provided by a certain embodiment of the utility model;

[0034] Figure 5 A schematic diagram of the structure of an alarm unit of a DC bus power failure alarm system provided by a certain embodiment of the utility model;

[0035] Figure 6 A schematic diagram of the circuit connection structure of a DC bus power failure alarm system provided in a certain embodiment of the utility model. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0037] The power supply of the relay protection device of the power plant and the backup power supply of the important power load are all taken from the DC bus. If the DC bus loses power, the equipment on the DC bus will stop working. In serious cases, personal, equipment or power grid accidents may occur due to the loss of system protection. Therefore, ensuring that the DC bus does not lose power is an important condition for the normal operation of the power system. The DC bus usually has two power sources: DC battery and AC charger, such as Figure 1 As shown. The AC charger is taken from the system AC power supply, and supplies power to the DC bus after rectification. It can also be used as a charging power source for the battery. When the AC power supply is normal, the AC power supply provides power to the DC bus after conversion; when the AC power supply fails, the battery pack in the DC operating power supply system provides power to the DC bus. Under normal circumstances, due to the dual protection of the battery and the charger, it is difficult for the DC bus to lose power. However, if the DC bus loses power, the relay protection device in the relay protection room loses power and the alarm power supply is also lost. On-site operating personnel can only judge the bus power failure by observing the power-on status of the relay protection device or the detection device. Due to the lack of sound and light alarms, operating personnel are prone to misjudgment, and it is difficult for on-site patrol personnel to find the cause of the fault in time, which prolongs the time for accident handling.

[0038] At present, the DC operating power system connection mode of one charging and one charging in the power system. The system is equipped with a set of chargers, a set of batteries, a section of DC bus, a battery inspection instrument and a system monitor. If the AC power fails and the battery pack is open-circuited at the same time, the charger and the battery pack will not be able to supply power to the DC bus normally, causing the system equipment on the DC bus to lose power. The relay protection equipment of the power plant is powered by the DC bus. Once the relay protection equipment loses power, the electrical primary equipment will not be protected, which is prone to safety accidents such as personal injury, equipment or power grid.

[0039] Example 1

[0040] See also Figure 1 , Figure 1 The following is a schematic diagram of the module structure of a DC bus power failure alarm system provided by a certain embodiment of the utility model. Figure 1 As shown, the utility model provides a DC bus power failure alarm system, comprising: a relay module 101, an alarm module 102 and a battery 103;

[0041] The alarm module 102 includes: a normally closed contact unit 104, a self-test contact unit 105 and an alarm unit 106;

[0042] One end of the relay module 101 is connected to the positive pole of the DC bus 107, and the other end of the relay module 101 is connected to the negative pole of the DC bus 107;

[0043] One end of the self-test contact unit 105 is connected to the positive pole of the DC bus 107, and the other end of the self-test contact unit is connected to the normally closed contact unit 104 and the alarm unit 106 respectively;

[0044] The other end of the alarm unit 106 is connected to the negative pole of the DC bus 107;

[0045] The DC bus 107 is connected to the battery pack 103;

[0046] The alarm module 102 is disposed between the relay module 101 and the battery pack 103 .

[0047] As an example of this embodiment, see Figure 2 , Figure 2 A schematic diagram of the structure of a relay module of a DC bus power failure alarm system provided in a certain embodiment of the utility model; the relay module 101 includes: a first relay 201 and a second relay 202;

[0048] One end of the first relay 201 is connected to the positive pole of the DC bus 107, and the other end of the first relay 201 is connected to the negative pole of the DC bus 107;

[0049] One end of the second relay 202 is connected to the positive pole of the DC bus 107, and the other end of the second relay 202 is connected to the negative pole of the DC bus 107. The relay module 101 may be: Voltage Relay: a relay used to monitor voltage changes in a circuit and trigger contact action according to a set threshold.

[0050] As another example of this embodiment, see Figure 3 , Figure 3 A schematic diagram of the structure of a self-checking contact unit of a DC bus power failure alarm system provided by a certain embodiment of the utility model; Figure 3 As shown, the self-test contact unit 105 includes: a normally open contact 301 and a normally closed self-locking contact 302;

[0051] One end of the normally closed self-locking contact 302 is connected to the positive electrode of the DC bus 107, and the other end of the normally closed self-locking contact 302 is connected to the normally closed contact unit 104 and the normally open contact 301 respectively;

[0052] The normally open contact 301 is connected in parallel with the normally closed contact unit 104 .

[0053] As another example of this embodiment, see Figure 4 , Figure 4 A schematic diagram of the structure of a normally closed contact unit of a DC bus power failure alarm system provided by a certain embodiment of the utility model; Figure 4 As shown,

[0054] The normally closed contact unit 104 includes: a first normally closed relay contact 401 and a second normally closed relay contact 402;

[0055] The first normally closed relay contact 401 and the second normally closed relay contact 402 are connected in parallel;

[0056] One end of the first normally closed relay contact 401 and one end of the second normally closed relay contact 402 are connected to the normally closed self-locking contact 302 , and the other end of the first normally closed relay contact 401 and the other end of the second normally closed relay contact 402 are connected to the alarm unit 106 .

[0057] As another example of this embodiment, see Figure 5 , Figure 5 A schematic diagram of the structure of an alarm unit of a DC bus power failure alarm system provided by a certain embodiment of the utility model; Figure 5 As shown,

[0058] The alarm unit 106 includes: a buzzer 501 or an audible and visual alarm device 502;

[0059] The alarm unit 106 is connected to the self-test contact unit 105 and the battery pack 103 respectively.

[0060] As another example of this embodiment, a circuit breaker 108 is provided between the positive and negative poles of the DC bus 107; the circuit breaker 108 is used to cut off the circuit current. Among them, the buzzer 501 can be: (1) Piezoelectric buzzer: a buzzer that generates sound by using the piezoelectric effect, which has the characteristics of small size, low power consumption, and fast response speed. (2) Electromagnetic buzzer: a buzzer that generates sound by using electromagnetic induction, usually composed of a coil and a diaphragm, and has the characteristics of clear sound and large volume. (3) Piezoelectric ceramic buzzer: a buzzer that generates sound by using piezoelectric ceramic materials, which has the characteristics of high efficiency and high stability. (4) Oscillating buzzer: a buzzer that generates sound by vibration, which is usually implemented by a mechanical oscillator or an oscillating plate.

[0061] As another example of this embodiment, the battery pack 103 is a backup power source, and the battery pack 103 is composed of a plurality of battery cells connected in series or in parallel.

[0062] In order to better explain the practical application of the utility model, its working principle is explained below: The utility model embodiment proposes a DC bus power failure alarm system. When the power grid system is operating normally, the relay module is in the power-on state, the normally closed contact unit is also in the power-on state and is open, and the buzzer is in the power-off state and does not work; when the DC bus loses power, the relay module is in the disconnected state, the normally closed contact unit is also in the disconnected state and is closed, and the battery pack supplies power to the buzzer, so that the buzzer is in the power-on state and issues an alarm; thus, the circuit connection structure can cause the buzzer to issue an alarm in time when the DC bus loses power to remind the maintenance personnel to repair the DC system, thereby improving the safety of the DC system. At the same time, when the normally closed self-locking contact is in the closed state, when the normally open contact is closed, the buzzer is in the power-on state and issues an alarm, thereby determining whether the buzzer is damaged, adding a fault self-discharge circuit structure, and further improving the safety of the DC system.

[0063] As an example of this embodiment, see Figure 6 , Figure 6 A schematic diagram of the circuit connection structure of a DC bus power failure alarm system provided by a certain embodiment of the utility model; Figure 6 As shown, the coil of the first relay 201 (J1) is connected to the DC bus 107, the first normally closed relay contact 401 (K1) is connected between the battery pack 103 and the buzzer 501 (HA), and the first normally closed relay contact 401 (K1) is connected in series with a buzzer 501 (HA) for power failure alarm; the coil of the second relay 202 (J2) is connected to the DC bus 107, the second normally closed relay contact 402 (K2) is connected between the battery pack 103 and the buzzer 501 (HA), and the second normally closed relay contact 402 (K2) is connected in series with a buzzer 501 (HA) for power failure alarm; of course, as one of the examples of this embodiment, more relays can also be used to connect to the power grid to better ensure the safe operation of the power grid.

[0064] When the DC bus 107 is energized, the coil of the first relay 201 (J1) is energized, the first normally closed relay contact 401 (K1) is opened, and the buzzer 501 (HA) does not sound. When the DC bus 107 is de-energized, the coil of the first relay 201 (J1) is de-energized, the first normally closed relay contact 401 (K1) is closed, and the buzzer 501 (HA) alarms; when the DC bus 107 is energized, the coil of the second relay 202 (J2) is energized, the second normally closed relay contact 402 (K2) is opened, and the buzzer 501 (HA) does not sound. When the DC bus 107 is de-energized, the coil of the second relay 202 (J2) is de-energized, the second normally closed relay contact 402 (K2) is closed, and the buzzer 501 (HA) alarms; the first relay 201 (J1) and the second relay 202 (J2) are backup for each other to prevent a relay failure from causing alarm failure;

[0065] When the DC bus 107 needs to be shut down for maintenance, press the normally closed self-locking contact 302 (SB1) to put the normally closed self-locking contact 302 (SB1) in an open state, and the HA buzzer alarm can be eliminated; SB2 is the normally open contact 301, which is used to regularly test whether the buzzer 501 (HA) is damaged. When the normally closed self-locking contact 302 (SB1) is in a closed state, press the normally open contact 301 (SB2). If the buzzer 501 (HA) alarm sounds, it means that the buzzer 501 (HA) is normal. If the buzzer 501 (HA) alarm does not sound, it means that the buzzer 501 (HA) is damaged and needs to be repaired or replaced. As a certain implementable method of this embodiment, the buzzer 501 (HA) can use a device with a built-in sound and light alarm device.

[0066] The embodiment of the utility model proposes a DC bus power failure alarm system, which adds an alarm unit as an alarm reminder for DC bus pressure loss, and improves the safety of the DC system through the alarm reminder of the alarm module; adds a battery pack as the power supply of the alarm unit to prevent the alarm unit from being unable to provide an alarm reminder in time when the DC bus pressure is lost, improves the accuracy of the DC system power failure alarm, and further improves the safety of the DC system; the relay module consists of a first relay and a second relay, and the first relay and the second relay are backup for each other; the problem of being unable to provide a line fault alarm when a certain relay is damaged is prevented, further ensuring the alarm reminder function and improving the safety of the DC system; adds a self-checking switch unit as a fault self-discharging circuit structure, thereby determining whether the alarm unit is damaged, and improving the safety of the DC system while ensuring the normal operation of the alarm unit.

[0067] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention.

[0068] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

Claims

1. A DC bus power failure alarm system, characterized in that: include: Relay modules, alarm modules and battery packs; The alarm module comprises: a normally closed contact unit, a self-test contact unit and an alarm unit; One end of the relay module is connected to the positive pole of the DC bus, and the other end of the relay module is connected to the negative pole of the DC bus; One end of the self-test contact unit is connected to the positive pole of the DC bus, and the other end of the self-test contact unit is connected to the normally closed contact unit and the alarm unit respectively; The other end of the alarm unit is connected to the negative pole of the DC bus; The DC bus is connected to the battery pack; The alarm module is arranged between the relay module and the battery pack.

2. A DC bus power failure alarm system as claimed in claim 1, characterized in that: The relay module comprises: a first relay and a second relay; One end of the first relay is connected to the positive pole of the DC bus, and the other end of the first relay is connected to the negative pole of the DC bus; One end of the second relay is connected to the positive pole of the DC bus, and the other end of the second relay is connected to the negative pole of the DC bus.

3. A DC bus power failure alarm system as claimed in claim 1, characterized in that: The self-checking contact unit comprises: a normally open contact and a normally closed self-locking contact; One end of the normally closed self-locking contact is connected to the positive pole of the DC bus, and the other end of the normally closed self-locking contact is respectively connected to the normally closed contact unit and the normally open contact; The normally open contact is connected in parallel with the normally closed contact unit.

4. A DC bus power failure alarm system as claimed in claim 3, characterized in that: The normally closed contact unit comprises: a first normally closed relay contact and a second normally closed relay contact; The first normally closed relay contact and the second normally closed relay contact are connected in parallel; One end of the first normally closed relay contact and one end of the second normally closed relay contact are connected to the normally closed self-locking contact, and the other end of the first normally closed relay contact and the other end of the second normally closed relay contact are connected to the alarm unit.

5. A DC bus power failure alarm system as claimed in claim 1, characterized in that: The alarm unit includes: a buzzer or an audible and visual alarm device; The alarm unit is connected to the self-test contact unit and the battery pack respectively.

6. A DC bus power failure alarm system as claimed in claim 5, characterized in that: A circuit breaker is provided between the positive and negative poles of the DC bus; the circuit breaker is used to cut off the circuit current.

7. A DC bus power failure alarm system as claimed in claim 1, characterized in that: The battery pack is a backup power source, and the battery pack is composed of a number of battery cells connected in series or in parallel.

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