CN204538792U - A kind of parallel power supply system and power module - Google Patents

Abstract

The utility model relates to a kind of parallel power supply system and power module.Power-supply system comprises a power module or at least two power modules in parallel, each power module comprises battery pack, control device and flow-restriction, battery pack and flow-restriction are arranged in series, and control device sampling connects corresponding battery pack, control device connects corresponding flow-restriction.Each power module is all supporting is provided with a control device, is conducive to the control of each power module; This control device is for monitoring the state information of battery pack and fault message and monitoring the flow-restriction of corresponding battery pack, control device only controls corresponding battery pack, when this battery pack breaks down, only this battery pack and power-supply system need be disconnected, setting program in control device does not need to change, and controls comparatively easy and flexible.

Description

A parallel power supply system and power module

technical field

The utility model relates to a parallel power supply system and a power supply module, belonging to the technical field of power supply applications.

Background technique

With the popularity of renewable energy such as photovoltaics and wind energy and the improvement of people's awareness, new energy has been vigorously promoted. Traditional lead-acid batteries are gradually being replaced by emerging lithium batteries due to their shortcomings such as large volume, heavy weight, serious pollution and short cycle life. At present, 15-16 series lithium iron phosphate batteries are gradually used in the field of communication power supplies to replace lead-acid batteries to form 48V DC The backup power supply supplies power to communication loads. Depending on the site, the capacity covers 50Ah, 100Ah, 150Ah, 200Ah, 300Ah, etc. Considering the adaptability and flexibility of the power supply module, parallel expansion of the modules can be realized. At the same time, photovoltaic energy storage power supplies for households are also on the rise. Using 48V lithium battery packs of different capacities for parallel connection, combined with on-grid/off-grid photovoltaic inverters, can meet the needs of different household users, thus forming a new energy solution for households. 48V power supply module is used to facilitate the versatility of the product.

According to actual needs, multiple lithium battery power modules are usually used in parallel. However, due to the consistency difference between each power module, there is a circulating current between the modules. If the circulating current is too large, it will cause a single module to charge overcurrent or The discharge overcurrent makes the parallel modules unable to work normally.

At present, there are roughly two schemes for parallel connection of lithium batteries. One uses a current equalizing circuit to realize parallel connection of lithium battery power modules. Using this scheme, the current equalizing circuit is always in working condition, which has low efficiency and greatly reduces the reliability of the system; The controller controls multiple parallel modules at the same time. For example, the Chinese patent application with the application number 201310232671.6 and the invention name "Battery Parallel Balance Circuit" discloses a battery system, between the positive main bus and the negative main bus , a plurality of battery packs are arranged in parallel, each battery pack is connected with a current balance circuit in series, and a controller is set in the whole system, and the controller controls and connects all the battery packs and the current balance circuit. In the battery system in this application, when a battery pack fails and exits the system, it is necessary to readjust the program of the main controller according to the re-determined number of parallel modules, so as to realize the parallel use of power modules. This method of control is relatively complicated and insufficient. Flexible, low efficiency, not conducive to the control of each power module.

Utility model content

The purpose of the utility model is to provide a parallel power supply system to solve the problem that the control of the traditional power supply system is relatively complicated. At the same time, the utility model also provides a power supply module.

In order to achieve the above object, the solution of the utility model includes a parallel power supply system, including a power supply module connected between the positive main bus and the negative main bus or at least two power supply modules arranged in parallel, and each power supply module is It includes a positive connection terminal and a negative connection terminal, a battery pack is connected in series on the line between the positive connection terminal and the negative connection terminal, each power supply module also includes a control device and a current limiting unit, and the battery The battery pack is connected in series with the current limiting unit, and the control device is connected to the battery pack corresponding to the sampling connection and the current limiting unit corresponding to the control connection.

The control device is BMS.

The positive main bus or the negative main bus is connected to the power line through a circuit breaker.

The circuit breaker is equipped with an emergency stop device for controlling the disconnection of the circuit breaker, the emergency stop device includes an emergency stop button, and the emergency stop button is serially arranged in the control circuit of the circuit breaker.

The battery pack is composed of several single cells connected in series, and the number of single cells in each battery pack is the same.

The battery pack is a lithium battery pack.

A power supply module, comprising a positive connection terminal and a negative connection terminal, a battery pack is connected in series between the positive connection terminal and the negative connection terminal, the power supply module also includes a control device and a current limiting unit, the The battery pack is arranged in series with the current limiting unit, and the control device samples and connects to the corresponding battery pack, and controls the connection to the corresponding current limiting unit.

The control device is BMS.

A manual switch is provided on the serial line of the battery pack.

The battery pack is a lithium battery pack.

Each power supply module is equipped with a control device, which is only used to control the corresponding battery pack, and is used to monitor the status information and fault information of the corresponding battery pack. It does not need to control other battery packs, which is beneficial to Each power module is effectively controlled, which avoids the problem of inconvenient control caused by only one control device for the entire power system. Moreover, when a power module fails, it only needs to withdraw the power module from the system, and other power The module is not affected, and the control devices in other power modules can still control the corresponding battery packs. The setting procedures do not need to be changed, and the control is relatively simple and flexible.

Description of drawings

Fig. 1 is a schematic structural view of an embodiment of a parallel power supply system;

Fig. 2 is a flow chart of the control strategy of the embodiment of the parallel power supply system;

Fig. 3 is a schematic structural diagram of an embodiment of a power module.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is described in further detail.

Example of Parallel Power Supply System

The parallel lithium battery power supply system shown in Figure 1 includes at least two lithium battery power supply modules 1 arranged in parallel between the positive busbar and the negative busbar, each lithium battery power supply module has a positive pole strong current terminal 5 and Negative strong electric terminal 6, a lithium-ion battery pack 2 is connected in series between the positive strong electric terminal 5 and the negative strong electric terminal 6, and each lithium-ion battery pack 2 is composed of several single cells connected in series Composition, the number of single batteries connected in series in the battery pack in each power module is the same, but the capacity can be different. The number of single cells connected in series in the battery pack is set according to the specific situation. In general, each lithium-ion battery pack is composed of 15 or 16 strings of large-capacity (each single cell’s capacity is greater than or equal to 10Ah) single lithium Ion battery composition.

Each lithium battery power module 1 is equipped with a battery management system (BMS) main board 3 , and the battery management system (BMS) main board 3 is sampled and connected to the corresponding lithium battery pack 2 . The battery management system monitors the status information and fault information of the single cells in the corresponding battery pack in real time, where the status information includes the voltage, current, SOC and SOH of the battery pack, the voltage and temperature of the single cells; the fault information includes the battery pack’s Overvoltage and undervoltage alarm and protection, high temperature and low temperature alarm and protection, overcurrent alarm and protection, short circuit alarm and protection, reverse connection alarm and protection, SOC capacity is too high and too low alarm, etc. The battery management system monitors the battery pack and transmits the monitored information to the display interface board or display (not shown in Figure 1) for display. The display interface board or display includes capacity indicator lights, running indicator lights and alarm indicators Lights, indicating status information and fault information; at the same time, the display interface board or display includes communication interfaces such as RS232, RS485 or CAN, which are used for communication between modules in parallel and communication with the host computer.

Each lithium power supply module 1 is provided with a current-limiting circuit board 4 inside, and the current-limiting circuit board 4 is connected in series with the corresponding battery pack, and the main board 3 of the battery management system controls and connects the corresponding current-limiting circuit board 4 . The main board of the battery management system controls the current-limiting circuit board 4 to turn on or off according to the working current of the corresponding power module. The charging current of the charging current is limited, and the corresponding power module will not be overcharged; when the charging current value of the lithium battery power module 1 is lower than another set current value, the charging current limiting function is turned off, and the power module enters normal operation at this time. state.

A manual switch 7 is arranged inside each power module and on the series circuit of the battery pack, which is used to disconnect the power module from other devices in time when the power module breaks down or other things happen. When multiple power modules are connected in parallel, connect the positive terminals of all power modules to the main positive copper bar 8 , and connect the negative terminals of all power modules to the main negative copper bar 9 . Then, the main positive copper bar 8 is connected to the load end P+ copper bar 14, the main negative copper bar 9 is connected to the load end P- copper bar 13, and the connection between the load end copper bar and the main positive and negative copper bars A circuit breaker 10 is connected in series. In order to disconnect the power supply system at any time, an emergency stop device is connected. The device includes a circuit breaker control circuit, which is composed of emergency stop button SB11, DCDC power supply module 12 and relay coil 15 In the circuit formed by series connection, the emergency stop button SB11 can be pressed when the power system encounters an emergency, and the emergency stop operation can be performed. The power-on and power-off of the relay coil 15 correspond to the opening and closing of the circuit breaker 10 . For example, when the power system needs to be stopped in an emergency, the emergency stop button SB11 is pressed, the relay coil 15 is energized, the circuit breaker 10 is turned off, and the emergency stop operation of the power system is realized. As other embodiments, an emergency stop device may not be provided, and the circuit breaker performs automatic circuit breaker according to the line condition.

As shown in Figure 2, it is a flow chart of the control strategy of the lithium battery power system.

First, the battery management system (BMS) judges whether the power module is in a charging state or a discharging state:

If the lithium battery power module is in the charging state, then judge whether the charging current of the module is greater than the over-charging and over-current threshold, and the continuous charging time is longer than 1min. Determine the charging current and the charging overcurrent threshold. If it is still greater than the charging overcurrent threshold, continue to repeat the above steps; if the charging current of the module is greater than the overcharging and overcurrent threshold, and the continuous charging time is less than 1min or the charging current is less than If the charging overcurrent threshold is set, the charging current limiting function does not need to be turned on, and the modules are connected in parallel to operate normally.

If the lithium battery power module is in the discharge state, then judge whether the discharge current of the module is greater than the discharge overcurrent threshold, and the continuous discharge time is greater than 1min, if so, cut off the discharge circuit, the discharge is interrupted, and the discharge circuit is closed after 1min, and the discharge continues , judge the discharge current of the module and the discharge overcurrent threshold again, if the discharge current is still greater than the discharge overcurrent threshold for 1min, continue to cycle the above steps; if the discharge current of the module is greater than the discharge overcurrent threshold, and the continuous discharge time is less than 1min or the discharge current is less than the discharge overcurrent threshold, the lithium battery power modules are connected in parallel and run normally.

If the lithium battery power modules connected in parallel are neither charged nor discharged, and there is no circulating current between them, the modules will operate normally after parallel connection, and the charging current limiting function will not be enabled.

In the above embodiment, a lithium battery is taken as an example. As other implementation manners, the power system may also be composed of other types of batteries, and the power system may also include only one power module.

In the above-mentioned embodiments, the power module includes a battery pack. As other implementations, each power module may include multiple battery packs, and these battery packs may be connected in series and parallel according to specific conditions.

Embodiment of the power module

The lithium battery power module shown in Figure 3 has a positive strong current terminal 5 and a negative strong current terminal 6, and a lithium ion is connected in series between the positive strong current terminal 5 and the negative strong current terminal 6. The battery pack 2, the lithium-ion battery pack is composed of several single cells connected in series. The number of single cells connected in series in the battery pack is the same, but the capacity can be different. The number of single cells connected in series in the battery pack 2 is set according to the specific situation. Generally, the lithium-ion battery pack is composed of 15 or 16 strings of large-capacity (each single cell’s capacity is greater than or equal to 10Ah) single lithium-ion Battery composition.

A battery management system (BMS) main board 3 is provided in the lithium battery power module, and the battery management system (BMS) main board 3 is sampled and connected to the lithium battery pack 2 . The battery management system (BMS) main board 3 monitors the status information and fault information of the single cells in the battery pack in real time, wherein the status information includes the voltage, current, SOC and SOH of the battery pack, the voltage and temperature of the single cells; the fault information includes Over-voltage and under-voltage alarm and protection of the battery pack, high temperature and low temperature alarm and protection, over-current alarm and protection, short-circuit alarm and protection, reverse connection alarm and protection, SOC capacity is too high and too low alarm, etc. The main board 3 of the battery management system (BMS) monitors the battery pack 2 and transmits the monitored information to the display interface board or the display 16 for display. The display interface board or the display 16 includes a capacity indicator light, a running indicator light and an alarm indicator The light indicates status information and fault information; at the same time, the display interface board or display 16 includes communication interfaces such as RS232, RS485 or CAN, and is used for communicating with the host computer.

A current-limiting circuit board 4 is arranged inside the lithium battery power module, and the current-limiting circuit board 4 is connected in series with the battery pack 2 , and the main board 3 of the battery management system (BMS) controls and connects the current-limiting circuit board 4 . The main board 3 of the battery management system (BMS) controls the opening or closing of the current limiting circuit board 4 according to the working current of the power module. The charging current of the lithium battery is limited, and the corresponding power module will not be overcharged; when the charging current value of the lithium battery power module is lower than another set current value, the charging current limiting function is turned off, and the power module enters the normal working state at this time .

A manual switch 7 is arranged inside the power module and on the series circuit of the battery pack, which is used to disconnect the power module from other devices in time when the power module breaks down or other things happen.

In the foregoing embodiments, a lithium battery is taken as an example. As other implementation manners, the power supply system may also be composed of other types or types of batteries.

In the above-mentioned embodiments, the power module includes a battery pack. As other implementation manners, the power module may include multiple battery packs, and these battery packs may be connected in series and parallel according to specific conditions.

Specific implementations have been given above, but the utility model is not limited to the described implementations. Without departing from the principle and spirit of the present utility model, the equivalent transformation or modification of individual components in the parallel power supply system and the power module in the embodiment still falls within the protection scope of the present utility model.

Claims (10)

1. a parallel power supply system, comprise and be connected to a power module between just total bus and negative total bus or at least two power modules be arranged in parallel, described each power module includes positive binding post and negative binding post, circuit between described positive binding post and negative binding post is serially connected with a battery pack, it is characterized in that, described each power module also includes a control device and flow-restriction, described battery pack and described flow-restriction are arranged in series, described control device sampling connects corresponding described battery pack, the described flow-restriction that control connection is corresponding.

2. parallel power supply system according to claim 1, is characterized in that, described control device is BMS.

3. parallel power supply system according to claim 1 and 2, is characterized in that, described just total bus or negative total bus are by circuit breaker connecting power line road.

4. parallel power supply system according to claim 3, it is characterized in that, described circuit breaker is supporting is provided with an emergency stop device controlling described circuit breaker and disconnect, and described emergency stop device comprises scram button, and described scram button string is located in the control loop of described circuit breaker.

5. parallel power supply system according to claim 1, is characterized in that, described battery pack is in series by several cells, and the number of the cell in each battery pack is identical.

6. parallel power supply system according to claim 1, is characterized in that, described battery pack is lithium battery group.

7. a power module, comprise positive binding post and negative binding post, circuit between described positive binding post and negative binding post is serially connected with a battery pack, it is characterized in that, described power module also comprises a control device and flow-restriction, described battery pack and described flow-restriction are arranged in series, the described flow-restriction that the described battery pack of described control device sampling connection correspondence, control connection are corresponding.

8. power module according to claim 7, is characterized in that, described control device is BMS.

9. the power module according to claim 7 or 8, is characterized in that, the series circuit of described battery pack is provided with hand switch.

10. the power module according to claim 7 or 8, is characterized in that, described battery pack is lithium battery group.