CN103227503A - Power supply system of transformer substation - Google Patents

Abstract

The present application discloses a substation power supply system for supplying power to substation loads. The system includes: a first battery pack, a second battery pack and a control device, wherein the control device includes: a first charger and a second charger , the first switch and the second switch, wherein, the input end of the first charger is connected with direct current; the output end is connected with the first storage battery; one end of the first switch is connected with the output end of the first charger, and the other One end is connected to the load of the substation; the input end of the second charger is connected to the direct current; the output end is connected to the second battery pack; one end of the second switch is connected to the output end of the second charger, and the other end is connected to the load of the substation connected. Compared with the prior art, the power supply system of the substation can avoid hidden dangers existing in the substation due to maintenance or charge and discharge tests on the backup battery pack.

Description

Substation power supply system

technical field

The present application relates to the field of electric power technology, in particular to a substation power supply system. the

Background technique

In the existing substation power supply system, valve-regulated lead-acid battery packs are generally used, and the battery packs are usually directly connected to the busbar and charged by the busbar. the

Although valve-regulated lead-acid battery packs have been popular with users because they do not need to add water for maintenance and do not need to adjust the density of the electrolyte, they have even been called "maintenance-free" lead-acid battery packs for a long time. . Because there is no maintenance during use, the problem is quickly exposed. The most important manifestation is that the battery life is significantly shortened. Many batteries that have been predicted to be used for more than eight years have basically no capacity after four years of use. What is even more frightening is that the valve-regulated lead-acid battery pack with a serious shortage of capacity has normal terminal voltage, normal temperature, and no leakage in the floating charge state, misleading users to think that everything is safe, but when the AC power failure or accident occurs at the station Under low voltage, the valve-regulated lead-acid battery pack used as a backup power supply collapsed for a short time. the

Therefore, during the use of the backup battery pack, it is necessary to regularly overhaul or charge and discharge the backup battery pack, and the backup battery pack must be disconnected. This leads to hidden dangers in the safe operation of the substation power supply system. For example, when the backup battery pack is overhauled, once the AC power failure or unexpected low voltage occurs, the substation will not be able to operate normally, or even an accident will occur. the

Contents of the invention

In view of this, the embodiment of the present application provides a substation power supply system to solve the hidden dangers existing in the existing substation power supply system when performing maintenance or charging and discharging tests on the backup battery pack. the

In order to achieve the above object, the technical solutions provided by the embodiments of the present application are as follows:

A substation power supply system for supplying power to substation loads, the system includes: a first battery pack, a second battery pack and a control device, wherein:

The control device includes: a first charger, a second charger, a first switch and a second switch, wherein:

The input end of the first charger is connected to direct current; the output end is connected to the first battery pack;

One end of the first switch is connected to the output end of the first charger, and the other end is connected to the load of the substation;

The input end of the second charger is connected to direct current; the output end is connected to the second battery pack;

One end of the second switch is connected to the output end of the second charger, and the other end is connected to the substation load. the

Preferably, the first switch is a relay switch. the

Preferably, the relay coil of the first switch is connected to the first battery pack. the

Preferably, the second switch is a relay switch. the

Preferably, the relay coil of the second switch is connected to the second battery pack. the

Preferably, a first diode is provided between the first switch and the substation load, and the anode of the first diode is connected to the first switch; the cathode of the first diode connected to the substation load. the

Preferably, a second diode is provided between the second switch and the substation load, and the anode of the second diode is connected to the second switch; the cathode of the second diode connected to the substation load. the

Preferably, the first storage battery pack is a lithium iron phosphate battery pack, and the second storage battery pack is a lead-acid iron battery pack. the

It can be seen from the above technical solutions that the substation power supply system provided by the embodiment of the present application can separately control different battery packs (at least two battery packs) to be connected to the load of the substation, so that when the AC power supply of the substation power supply system fails, through Closing the switch K on any battery pack controls the corresponding battery pack to supply power to the substation load, so that at least two battery packs can serve as backups for each other. the

Compared with the existing technology, when a battery pack in the power supply system of the substation needs to be overhauled or a charge-discharge test is performed, the battery pack can be separated from the busbar and disconnected from the load of the substation of the power supply station. Another battery pack is used as a backup power source alone, which can ensure that when a certain battery pack is maintained, the substation power supply system has a backup power supply, avoiding hidden dangers in the substation due to maintenance or charging and discharging tests on the backup battery pack. the

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments described in this application. Those skilled in the art can also obtain other drawings based on these drawings without creative work. the

Fig. 1 is the structural representation of a kind of substation power supply system provided by the embodiment of the present application;

Fig. 2 is a schematic structural diagram of another substation power supply system provided by an embodiment of the present application. the

Detailed ways

In order to enable those skilled in the art to better understand the technical solutions in the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described The embodiments are only some of the embodiments of the present application, but not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without creative efforts shall fall within the scope of protection of this application. the

Embodiment one:

Fig. 1 is a schematic structural diagram of a substation power supply system provided by an embodiment of the present application. the

As shown in Figure 1, 10 in the figure is an alternating current, 40 is a substation load, and the power supply system of the substation includes: a first battery pack 70, a second battery pack 30 and a control device, wherein:

The first battery pack 70 can be a lithium iron phosphate battery pack, the second battery pack 30 can be a lead-acid lithium iron battery pack, and as shown in FIG. 1 , the control device can include: a first control device 21 and a second control device 22 . the

As shown in Figure 2, the first control device 21 includes: a first charger 201 and a first switch K1, wherein: the input end of the first charger 201 is connected to the direct current 10; the output end is connected to the lead-acid iron A lithium battery pack 30 is connected. The function of the first charger 201 is to use the direct current 10 to charge the lead-acid lithium iron battery pack 30 . In the embodiment of the present application, the direct current 10 is usually a 380-volt direct current (that is, AC-380V). the

One end of the first switch K1 is connected to the output end of the first charger 201 , and the other end is connected to the substation load 40 . When the first switch K1 is closed, the lead-acid lithium iron battery pack 30 will supply power to the substation load 40, and when the first switch K1 is opened, the connection between the lead-acid lithium iron battery pack 30 and the substation load 40 will be disconnected . the

The second control device 22 includes: a second charger 202 and a first switch K2 , wherein: the input end of the second charger 202 is connected to the direct current 10 ; the output end is connected to the lithium iron phosphate battery pack 70 . The function of the second charger 202 is to use the direct current 10 to charge the lithium iron phosphate battery pack 70 . In the embodiment of the present application, the direct current 10 is also a 380-volt direct current (that is, AC-380V). the

One end of the second switch K2 is connected to the output end of the second charger 202 , and the other end is connected to the substation load 40 . When the second switch K2 is closed, the lithium iron phosphate battery pack 70 will supply power to the substation load 40 , and when the second switch K2 is opened, the connection between the lithium iron phosphate battery pack 70 and the substation load 40 will be disconnected. the

In the embodiment of the present application, a lead-acid lithium iron battery pack and a lithium iron phosphate battery pack are taken as examples for illustration. In other embodiments of the present application, the lead-acid lithium iron battery pack or the lithium iron phosphate battery pack can be respectively Multiple. the

In actual use, in the substation power supply system provided by the embodiment of the present application, the lithium iron phosphate battery pack and the lithium iron lead acid battery pack cannot be operated in parallel for a long time. And because the load 40 of the substation belongs to a class of loads, no intermittent power supply is allowed under any circumstances, that is, when the AC power of the load 40 of the substation is disconnected, at least one battery pack must be guaranteed to supply power to the load 40

In addition, the charging process of the lead-acid lithium iron battery pack 30 is controlled as follows:

The valve-controlled sealed lead-acid lithium battery pack 30 is used for balanced charging, and when one of the following situations occurs, it will switch to balanced charging: (1), indicating that the floating charge voltage of the battery is less than 2.20V; (2) after an accident or emergency discharge, It needs to be recharged in a short time; (3) Regularly recharge the lead-acid lithium iron battery pack. the

The charging process of the lithium iron phosphate battery pack 70 includes the following three stages:

The first stage, current-limited charging, during this stage the voltage at terminal 70 of the lithium iron phosphate battery pack continues to rise;

The second stage is constant voltage and constant charging. With the recovery of the lithium iron phosphate battery capacity, the charging current will automatically drop, and the terminal voltage of the lithium iron phosphate single battery will reach a certain value, such as 3.42V;

The third stage is supplementary charging. When the terminal voltage of the single battery reaches a certain value of 3.42V, the charging voltage continues to rise, so that the terminal voltage of the single battery rises to 3.50V. At this time, the charging current is almost close to 0, and then turns to During normal charging, the terminal voltage of the single battery is maintained at 3.42V. the

The substation power supply system provided in the embodiment of the present application can separately control the lithium iron phosphate battery pack or the lead acid lithium battery pack to be connected to the substation load, so that when the AC power supply of the substation power supply system fails, any battery pack The switch K on the switch is closed, and the corresponding battery pack is controlled to supply power to the substation load, so that the lithium iron phosphate battery pack and the lithium iron lead acid battery pack can be used as backup for each other. the

Compared with the existing technology, since the lithium iron phosphate battery pack is used as the backup power supply of the lead-acid lithium battery pack, the advantages of the lithium iron phosphate battery pack are used to supplement the disadvantages of the lead-acid lithium battery pack, making the substation power supply The system is safer, more environmentally friendly, and has a longer service life and easier maintenance. the

At the same time, when the lead-acid lithium battery pack in the substation power supply system of the lithium iron phosphate battery pack needs to be overhauled or a charge and discharge test is performed, the lead-acid lithium iron battery pack can be separated from the busbar and disconnected from the power supply substation. For the connection between the loads, another lithium iron phosphate battery pack is used as a backup power source alone, which can ensure that the substation power supply system has a backup power supply when maintaining the lead-acid lithium battery pack, avoiding damage to the backup lead-acid lithium battery pack. There are hidden dangers in substations caused by maintenance or charging and discharging tests. the

Embodiment two:

When one of the lead-acid lithium iron battery pack 30 or the lithium iron phosphate battery pack 70 supplies power to the substation load, for the convenience of the operator, the connection situation of the first switch K1 and the second switch K2 can be clearly understood. In an example, the control device further includes: at least one diode, the diode is located between the first switch and the load of the substation of the power supply station, or between the second switch and the load of the substation of the power supply station, and the current of the diode flows to the battery pack The medium current flows in the same direction to the load of the power station substation, so that when a certain battery pack supplies power to the load of the power station substation, the diode will be energized and light up. the

Fig. 2 is a schematic structural diagram of another lithium iron phosphate battery substation power supply system provided in the embodiment of the present application. the

As shown in Figure 2, the control device also includes: a first diode D1 and a second diode D2, wherein:

The first diode D1 is arranged between the first switch K1 and the substation load 40, and the anode of the first diode D1 is connected to the first switch D1; the cathode of the first diode D1 is connected to the substation load 40 ;

The second diode D2 is arranged between the second switch K2 and the substation load 40, and the anode of the second diode D2 is connected to the second switch K2; the cathode of the second diode D2 is connected to the substation load 40 . the

In addition, in the embodiment of the present application, the first switch K1 and/or the second switch K2 may be relay switches, and when the first switch and/or the second switch K2 are relay switches, the relay coil of the first switch K1 and The lead-acid lithium iron battery pack 30 is connected and powered by the lead-acid lithium iron battery pack 30, and the relay coil of the second switch K2 is connected with the described lithium iron phosphate battery pack 70, and is powered by the lithium iron phosphate battery pack 70. powered by. the

A lithium iron phosphate battery substation power supply system provided by this application has been introduced in detail above. In this paper, specific examples are used to illustrate the principle and implementation of this application. The description of the above embodiments is only used to help understand this application. The method of application and its core idea; at the same time, for those of ordinary skill in the art, according to the idea of this application, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be understood For the limitation of this application. the

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other. the

It should be noted that, in this article, descriptions of relationships such as "greater than" or "exceeded" or "higher than" or "less than" or "below" can be understood as "greater than and not equal to" or " "Less than and not equal to" can also be understood as "greater than or equal to" or "less than or equal to", without necessarily requiring or implying a limited or inherent situation. the

In addition, in this document, relational terms such as "first" and "second", etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply that these entities or operations Any such actual relationship or order exists between. Also, in this document, the term "comprises", "comprises" or any other variation thereof is intended to cover a non-exclusive inclusion such that a process, method, article or apparatus comprising a set of elements includes not only those elements, but also includes Other elements not expressly listed, or elements inherent in the process, method, article, or apparatus are also included. Without further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of additional identical elements in the process, method, article or apparatus comprising said element. the

It should be noted that the above is only a part of the preferred specific implementation of the technical solution of the application, so that those skilled in the art can fully understand or realize the application, rather than all embodiments, the general principles defined herein can be found in Other embodiments can be implemented without departing from the spirit or scope of the application. Therefore, based on the above embodiments, for those of ordinary skill in the art, without departing from the principle of the application and without making creative work, various obvious modifications and embellishments can also be made, through these modifications and embellishments All other obtained embodiments can be applied to the technical solution of the present application, and these do not affect the realization of the present application, and should belong to the protection scope of the present application. Therefore, the present application will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (8)

1. transformer station's electric power system is used for transformer station's load is powered, and it is characterized in that this system comprises: first batteries, second batteries and control device, wherein:

Described control device comprises: first charger, second charger, first switch and second switch, wherein,

The input of described first charger is connected with direct current; Output is connected with described first batteries;

One end of described first switch is connected with the output of described first charger, and the other end is connected with described transformer station load;

The input of described second charger is connected with direct current; Output is connected with described second batteries;

One end of described second switch is connected with the output of described second charger, and the other end is connected with described transformer station load.

2. system according to claim 1 is characterized in that, described first switch is a relay switch.

3. system according to claim 2 is characterized in that, the relay coil of described first switch is connected with described first batteries.

4. system according to claim 1 is characterized in that, described second switch is a relay switch.

5. system according to claim 4 is characterized in that, the relay coil of described second switch is connected with described second batteries.

6. according to claim 3 or 5 described systems, it is characterized in that, between described first switch and the load of described transformer station first diode is set, and the anode of described first diode is connected with described first switch; The negative electrode of described first diode is connected with described transformer station load.

7. system according to claim 6 is characterized in that, between described second switch and the load of described transformer station second diode is set, and the anode of described second diode is connected with described second switch; The negative electrode of described second diode is connected with described transformer station load.

8. system according to claim 7 is characterized in that, described first batteries is the ferric phosphate lithium cell group, and described second batteries is a plumbic acid iron cell group.

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