CN114465303A

CN114465303A - Energy storage battery protection system for taking electricity through battery direct current side

Info

Publication number: CN114465303A
Application number: CN202210024909.5A
Authority: CN
Inventors: 石正平; 陈仕捷; 方焱琦; 张新池
Original assignee: Fujian Times Nebula Technology Co Ltd
Current assignee: Fujian Times Nebula Technology Co Ltd
Priority date: 2022-01-10
Filing date: 2022-01-10
Publication date: 2022-05-10

Abstract

The invention discloses an energy storage battery protection system for taking electricity through a direct current side of a battery, which comprises a first switch, a second switch, a battery cabinet, a shunt release, a time delay relay, a first converter, a main positive relay, a main negative relay and a direct current bus, the direct current bus bar comprises a first direct current bus bar and a second direct current bus bar, the positive electrode of the battery cabinet is electrically connected with the first direct current bus bar and the positive input end of the converter through the first switch, the negative electrode of the battery cabinet is electrically connected with the second direct current bus bar and the negative input end of the first converter through the second switch, the time delay relay and the shunt release are electrically coupled between the positive output end and the negative output end of the first converter, the positive pole of battery cabinet is through main positive relay electricity is connected the female arranging of first direct current, the negative pole of battery cabinet is through main negative relay electricity is connected the female arranging of second direct current.

Description

Energy storage battery protection system for taking electricity through battery direct current side

Technical Field

The invention relates to the technical field of energy storage control, in particular to an energy storage battery protection system for taking electricity through a battery direct current side.

Background

In the existing energy storage system, a UPS is usually adopted to supply power to a control device in an auxiliary manner, but in a general conventional project, the energy of a lead-acid storage battery equipped with the UPS is not large, and feeding is likely to occur after the UPS is not started for a long time, or the UPS cannot support the required time due to the fact that too many external devices for auxiliary power supply are provided and the power is too large, so that the whole system cannot be started without the external power supply.

Therefore, in order to deal with more variable environments, the prior art can still maintain the black start capability after long-time non-start, can support higher power and operate more equipment for a long time, and therefore, the direct-current side power supply of the battery cabinet is used for replacing a UPS (uninterrupted power supply).

However, in the structure in the prior art, under the condition of long-time non-starting, the direct current side of the battery cabinet is continuously discharged, so that the battery cabinet is over-discharged, the over-discharge causes the internal battery to be damaged, and the energy storage system cannot be started.

And under the parallelly connected condition of many battery cabinets, get the electricity through the direct current side of single electric cabinet for a long time, can cause this electric cabinet loss great, in the in-process of normal use, lead to unbalance between the electric cabinet easily, lead to the decline of charge-discharge capacity.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the utility model provides an energy storage battery protection system of getting electricity through battery direct current side prevents that the battery cabinet from leading to damaging because of the overdischarge, and can avoid the problem of many electric cabinets unbalance that single electric cabinet got the electricity and leads to.

In order to solve the technical problems, the invention adopts a technical scheme that:

an energy storage battery protection system for taking electricity through a battery direct current side comprises a first switch, a second switch, a battery cabinet, a shunt release, a time delay relay, a first converter, a main positive relay, a main negative relay and a direct current bus, wherein the direct current bus comprises a first direct current bus and a second direct current bus, the positive electrode of the battery cabinet is electrically connected with the first direct current bus and the positive input end of the first converter through the first switch, the negative electrode of the battery cabinet is electrically connected with the second direct current bus and the negative input end of the first converter through the second switch, and the time delay relay and the shunt release are electrically coupled between the positive output end and the negative output end of the first converter; the positive pole of battery cabinet is through main positive relay electricity is connected the female row of first direct current, the negative pole of battery cabinet is through main negative relay electricity is connected the female row of second direct current.

The invention has the beneficial effects that: when the power is on, the first switch and the second switch are manually closed, the output current of the first converter is supplied to each device and the delay relay, the upper computer operation BMS of the energy storage system controls the closed main negative relay and the main positive relay, the delay relay completes the delay after the direct-current busbar supplies power, the shunt release controls the first switch and the second switch to be disconnected, and the problem of imbalance among the multiple cabinets caused by battery damage and long-time discharge of the single battery cabinet after shutdown is avoided.

Drawings

Fig. 1 is a schematic structural diagram of an energy storage battery protection system for taking electricity through a battery dc side according to the present invention.

Fig. 2 is a power-on flow chart of the energy storage battery protection system for taking power from the dc side of the battery according to the present invention.

FIG. 3 is a power-off flow chart of the energy storage battery protection system for taking power from the DC side of the battery according to the present invention

FIG. 4 is a schematic structural diagram of another energy storage battery protection system for obtaining electricity through the DC side of a battery according to the present invention

Description of reference numerals:

1. a circuit breaker; 2. a battery cabinet; 3. a shunt release; 4. a time delay relay; 5. a DC/DC converter; 6. a DC/AC converter; 7. a slave control box; 8. a direct current bus bar; 81. a first direct current bus bar; 82. a second direct current bus bar; 91. a first diode; 92. a second diode; 10. a third circuit breaker; a battery management system BMS.

Detailed Description

In order to explain technical contents, achieved objects, and effects of the present invention in detail, the following description is made with reference to the accompanying drawings in combination with the embodiments.

Referring to fig. 1, an embodiment of the present invention provides an energy storage battery protection system for taking electricity from a battery dc side, including a first switch, a second switch, a battery cabinet, a shunt release, a time delay relay, a first converter, a main positive relay, a main negative relay, and a dc bus, where the dc bus includes a first dc bus and a second dc bus, a positive electrode of the battery cabinet is electrically connected to the first dc bus and a positive input terminal of the first converter through the first switch, a negative electrode of the battery cabinet is electrically connected to the second dc bus and a negative input terminal of the first converter through the second switch, and a positive output terminal and a negative output terminal of the first converter are electrically coupled to the time delay relay and the shunt release; the positive pole of battery cabinet is through main positive relay electricity is connected the first direct current female arranging, the negative pole of battery cabinet is through main negative relay electricity is connected the female arranging of second direct current.

As can be seen from the above description, the beneficial effects of the present invention are: when the power is on, the first switch and the second switch are manually closed, the first converter outputs current to supply to each device and the time delay relay, the upper computer operation BMS of the energy storage system controls the main negative relay and the main positive relay to be closed, the time delay relay finishes time delay after the direct-current busbar supplies power, the shunt release controls the first switch and the second switch to be disconnected, and the battery cabinet is prevented from being continuously discharged after shutdown to cause battery damage.

Further, the high-voltage direct current converter further comprises a third switch which is connected between the positive output end and the negative output end of the first converter in series with the time delay relay and the shunt release.

According to the description, after the first switch and the second switch are disconnected, the third switch is disconnected, so that the situation that the shunt release is always in a working state and possibly damaged due to long-time working because the delay relay is continuously electrified is avoided.

Further, the third switch, the first switch and the second switch are linked.

According to the description, the third switch, the first switch and the second switch are linked, so that the third switch is automatically disconnected after the first switch and the second switch are disconnected, the stability and the safety of a system are improved, meanwhile, the third switch can be disconnected after the shunt release is electrified to work, and the shunt release is not easy to damage.

Furthermore, after the first switch and the second switch are closed and the delay relay delays for a set time, the shunt release controls the first switch and the second switch to be switched off.

Furthermore, after the first switch, the second switch and the third switch are closed, the coil of the delay relay is powered on, after the delay relay delays for a set time, the main contact of the delay relay is closed, and after the shunt release is powered on, the first switch, the second switch and the third switch are controlled to be disconnected.

As can be seen from the above description, after the time delay relay delays for the set time, the main contact is closed, so that the shunt release is powered on, the control of the shunt release by the time delay relay is realized, and the closing of the first switch, the second switch, and the third switch is further controlled.

Further, the third switch, the first switch and the second switch are integrated on the same circuit breaker.

As can be seen from the above description, the third switch, the first switch and the second switch are integrated on the same circuit breaker, so that the three-linkage circuit breaker work is completed by adopting one 3P circuit breaker, the circuit is simplified, and the cost is saved.

Furthermore, the power supply also comprises a second converter, and the input end of the second converter is electrically connected with the output end of the first converter.

As can be seen from the above description, the plurality of converters allows the system to have a plurality of output voltages, which can meet the requirements of more electric devices.

Further, the first converter is a DC/DC converter, and the second converter is a DC/AC converter.

As can be seen from the above description, the converter includes a DC/DC converter and a DC/AC converter, and has both a direct current output and an alternating current output, and can be used for both direct current equipment and alternating current equipment.

Further, the output voltage of the DC/AC converter is the mains voltage.

As can be seen from the above description, the output voltage of the DC/AC converter is the mains voltage, and is directly compatible with the mains.

Further, the set time is the time required by the direct-current busbar to finish the high voltage.

According to the above description, the setting time is the time required by the dc bus to complete the high voltage, so that the first switch and the second switch are only switched off after the high voltage on the dc bus is completed, and the situation that the high voltage cannot be completed normally is avoided.

The direct current bus bar further comprises a first diode and a second diode, wherein the cathode of the first diode is electrically connected with the first switch, and the anode of the first diode is electrically connected with the first direct current bus bar; and the anode of the second diode is electrically connected with the second switch, and the cathode of the second diode is electrically connected with the second direct-current busbar.

According to the description, the first diode and the second diode are used for preventing the energy storage system from generating voltage on the direct-current busbar before the energy storage system finishes high voltage application, and preventing direct-current side current from flowing into the direct-current busbar to cause misjudgment of the energy storage system.

The power distribution tripping device further comprises a battery management system BMS, wherein the battery management system BMS is connected with two ends of the distribution tripping device and controls the distribution tripping device to be powered on under the abnormal condition, so that the first switch and the second switch are disconnected

As can be seen from the above description, in the direct current side power-taking process, the BMS can monitor the state of the battery in real time, and if the over-temperature, the low SOC of the battery and other alarms occur, the BMS can output a 24V power supply through the D + and the D-to enable the shunt release to be powered on and disconnect the first switch and the second switch.

The energy storage battery protection system capable of taking electricity through the battery direct current side is used for the battery cabinet direct current side of the energy storage equipment, and internal battery damage caused by over-discharge of the battery cabinet direct current side is prevented.

Example one

Referring to fig. 1, an energy storage battery protection system for taking electricity from a battery dc side according to the present embodiment includes a circuit breaker 1, a battery cabinet 2, a shunt release 3, a delay relay 4, a first converter 5, a second converter 6, a slave control box 7, and a dc bus 8.

Wherein, the DC bus bar 8 comprises a first DC bus bar 81 and a second DC bus bar 82, the first DC bus bar 81 is provided with a first diode 91, the second DC bus bar 82 is provided with a second diode 92, the circuit breaker 1 comprises a first circuit breaker and a second circuit breaker which are linked, the anode of the battery cabinet 2 is electrically connected with the first DC bus bar 81 through the first circuit breaker and the first diode 91, the cathode of the battery cabinet 2 is electrically connected with the second DC bus bar 82 through the second circuit breaker and the second diode 92, the anode of the battery cabinet 2 is electrically connected with the first DC bus bar 81 through a main positive relay of the slave control box 7, the cathode of the battery cabinet 2 is electrically connected with the second DC bus bar 82 through a main negative relay of the slave control box 7, the cathode of the first diode 91 is connected to the first circuit breaker, the anode is connected to the main positive relay, the cathode of the second diode 92 is connected to the main negative relay, and the anode is connected to the second circuit breaker.

The first diode 91 and the second diode 92 are used for preventing the energy storage system from generating voltage on the direct current busbar before the energy storage system finishes high voltage application, so that the energy storage system generates misjudgment.

A cathode of the first diode 91 is electrically connected to the first input of the first inverter 5 and an anode of the second diode 92 is electrically connected to the second input of the first inverter 5.

Further, the first converter 5 may be a DC/DC converter, so that the DC/DC converter converts the direct voltage output of the battery cabinet 2 into a first voltage, for example, 24V. Further, a second converter 6 is electrically connected to two output terminals of the second converter 5, and the second converter 6 may be a DC/AC converter, and converts the output of the DC/DC converter 5 into an alternating voltage of the energy storage device, for example, 220V alternating voltage.

The delay relay 4, the shunt release 3 and the third switch 10 are electrically coupled between the positive output terminal and the negative output terminal of the first converter 5. The delay relay 4 comprises a coil and a main contact, one end of the coil is connected with the output end of the first converter 5, one end of the coil is connected with the third switch 10, and the shunt release 3 is connected with the main contact of the delay relay 4.

When the circuit breaker 1 is closed, the first converter 5 outputs voltage to supply power to the delay relay 4, the delay relay 4 is powered on for timing, the main contact of the delay relay 4 is attracted after timing is completed, the shunt release 3 is powered on to start working, the circuit breaker 1 is cut off, the third switch 10 is linked with the circuit breaker 1 and is disconnected together after the circuit breaker 1 is cut off, and the delay relay 4 is prevented from being continuously powered on, so that the shunt release 3 is always in a working state, and possible damage of long-time working is caused.

In this embodiment, the third switch 10 is specifically the third breaker of the breaker 1, so that one 3P breaker 1 is adopted to complete the work of the three linked breakers 1, thereby simplifying the circuit and saving the cost.

It should be noted that the specific topology of the first converter 5 and the second converter 6 of the present embodiment is not limited to that shown in the drawings, and the effects of the present invention can still be achieved. For example, the first converter 5 may be a DC/AC converter, the shunt release 3 and the delay relay 4 may take power from the output terminal of the DC/AC converter, and only the delay relay 4 and the shunt release 3 with appropriate operating voltages need to be selected, and at this time, the second converter 6 may be an AC/DC converter, and the input terminal of the AC/DC converter may be connected to the output terminal of the DC/AC converter, so as to achieve the purpose of the present invention.

In the operation of the present invention, the working process of the power-on condition is as shown in fig. 2:

firstly, a circuit breaker 1 is manually closed, a battery cabinet 2 outputs electric energy to a first converter 5 through a direct current side, the first converter 5 converts direct current voltage of the battery cabinet 2 into first voltage (for example, 24V direct current) to be output, the first voltage is supplied to each control device of an energy storage system for working, and meanwhile, a second converter 6 receives the 24V direct current and converts the 24V direct current into 220V alternating current; because the third switch 10 is linked with the circuit breaker 1, the third switch and the circuit breaker 1 are closed simultaneously, at the moment, the coil of the time delay relay 4 is electrified, and the time delay timing is started.

Further, whether high voltage application is finished or not is judged, if the high voltage application is finished, the battery cabinet 2 supplies power to the first converter through the direct-current busbar, after the time delay of the time delay relay 4 is set for time, the main contact of the time delay relay 4 is closed, the shunt release 3 is electrified to start working, and the direct-current side circuit breaker 1 and the third switch 10 of the electric cabinet are disconnected, wherein in the embodiment, the set time can be selected within a range of 5-10 minutes.

If in a special case, for example, only the internal information needs to be checked, the circuit breaker 1 can be closed without applying high voltage, and in this case, the system is powered for a short time, and then the shutdown is automatically completed without charging and discharging the energy storage system.

The working process of the power-off situation is shown in fig. 3:

judging whether the circuit breaker 1 is closed, wherein the third switch 10 is closed while the circuit breaker 1 is closed; after the circuit breaker 1 is closed, a coil of the time delay relay 3 is electrified and starts to time, and a first converter converts the direct-current voltage of the battery cabinet into a first voltage for output; further, an upper computer of the energy storage system operates the BMS to control a main negative relay and a main positive relay in the slave control box 7 to be disconnected, so that high voltage is discharged, and in the process, the circuit breaker 1 replaces a direct-current bus to supply power to the first converter 5 to support normal work of all equipment of the energy storage system;

when the time delay of the time delay relay 4 is finished within the preset time, the main contact is closed, the shunt release 3 is electrified to work, the circuit breaker 1 is disconnected, and the system is powered off.

In an emergency, the high-voltage shutdown system can also be operated without closing the circuit breaker 1.

Example two

As shown in fig. 4, the system of this embodiment further includes a battery management system BMS on the basis of the first embodiment, the battery management system BMS is connected to both ends of the shunt release, the BMS monitors the state of the battery in real time during the dc side power take-off process, and if an alarm such as an over-temperature, a low temperature, and an over-low battery SOC occurs, the BMS outputs a 24V power through the D + and the D-output to energize the shunt release and disconnect the first switch and the second switch.

And under the condition that a plurality of battery cabinets are connected in parallel in the figure 4, the direct current side of the battery cabinet for starting cannot be overdischarged through the control of the shunt release, the delay relay and the battery management system BMS, so that the loss of the electric cabinet is large, and the balance among the electric cabinets in the normal use process is ensured.

In summary, according to the energy storage battery protection system for taking electricity from the direct current side of the battery provided by the invention, when the battery is powered on, the circuit breaker is manually closed, the output current of the converter is supplied to each device and the delay relay, the upper computer of the energy storage system operates the BMS to control the closing of the main negative relay and the main positive relay, the delay relay completes the delay after the power supply of the direct current bus, the shunt release controls the circuit breaker to be opened, the battery damage caused by the continuous discharge of the battery cabinet after the shutdown is avoided, the third switch is automatically opened after the circuit breaker is opened, the stability and the safety of the system are improved, and the first diode and the second diode are used for avoiding the voltage generation on the direct current bus before the energy storage system completes the high voltage application, so that the energy storage system generates the misjudgment.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all equivalent changes made by using the contents of the present specification and the drawings, or applied directly or indirectly to the related technical fields, are included in the scope of the present invention.

Claims

1. The utility model provides an energy storage battery protection system of getting electricity through battery direct current side which characterized in that: the direct-current bus bar comprises a first switch, a second switch, a battery cabinet, a shunt release, a time delay relay, a first converter, a main positive relay, a main negative relay and a direct-current bus bar, wherein the direct-current bus bar comprises a first direct-current bus bar and a second direct-current bus bar, the positive electrode of the battery cabinet is electrically connected with the first direct-current bus bar and the positive input end of the first converter through the first switch, the negative electrode of the battery cabinet is electrically connected with the second direct-current bus bar and the negative input end of the first converter through the second switch, and the time delay relay and the shunt release are electrically coupled between the positive output end and the negative output end of the first converter; the positive pole of battery cabinet is through main positive relay electricity is connected the female row of first direct current, the negative pole of battery cabinet is through main negative relay electricity is connected the female row of second direct current.

2. The energy storage battery protection system taking electricity through the direct current side of the battery as claimed in claim 1, characterized in that: the third switch is connected between the positive output end and the negative output end of the first converter in series with the delay relay and the shunt release.

3. The energy storage battery protection system taking electricity through the direct current side of the battery as claimed in claim 2, characterized in that: the third switch, the first switch and the second switch are linked.

4. The energy storage battery protection system taking electricity through the direct current side of the battery as claimed in claim 3, characterized in that: the third switch, the first switch and the second switch are integrated on the same circuit breaker.

5. The energy storage battery protection system taking electricity through the direct current side of the battery as claimed in claim 1, characterized in that: after the first switch and the second switch are closed and the delay relay delays for a set time, the shunt release controls the first switch and the second switch to be disconnected.

6. An energy storage battery protection system taking electricity through the direct current side of the battery as claimed in any one of claims 2 to 4, wherein: after the first switch, the second switch and the third switch are closed, the coil of the delay relay is electrified, after the delay relay delays for a set time, the main contact of the delay relay is closed, and after the shunt release is electrified, the first switch, the second switch and the third switch are controlled to be disconnected.

7. The energy storage battery protection system taking electricity through the direct current side of the battery as claimed in claim 1, characterized in that: the converter further comprises a second converter, and the input end of the second converter is electrically connected with the output end of the first converter.

8. The energy storage battery protection system taking electricity through the direct current side of the battery as claimed in claim 7, wherein: the first converter is a DC/DC converter and the second converter is a DC/AC converter.

9. The energy storage battery protection system taking electricity through the direct current side of the battery as claimed in claim 1, characterized in that: the set time is the time required by the direct-current busbar to finish high voltage.

10. The energy storage battery protection system taking electricity through the direct current side of the battery as claimed in claim 1, characterized in that: the LED further comprises a first diode and a second diode; the cathode of the first diode is electrically connected with the first switch, and the anode of the first diode is electrically connected with the first direct current bus bar; and the anode of the second diode is electrically connected with the second switch, and the cathode of the second diode is electrically connected with the second direct-current busbar.

11. The energy storage battery protection system taking power from the direct current side of the battery as claimed in claim 1, further comprising a battery management system BMS, wherein the battery management system BMS is connected to two ends of the shunt release and controls the shunt release to be powered on under abnormal conditions, so that the first switch and the second switch are turned off.