Charging and discharging system for energy-saving storage battery

Abstract

The utility model discloses a charging and discharging system for an energy-saving storage battery, which belongs to the field of new energy, and adopts an energy storage battery pack to charge a test battery pack, so as to realize reutilization of electric energy, and switch to a power grid to supply power when the electric quantity is insufficient; when the load resistor is used as a discharge main body, the fan timely radiates heat to protect the load resistor. The system mainly comprises a battery charging controller and a battery discharging controller, the battery discharging controller is connected with a plurality of DC / DC modules, the plurality of DC / DC modules are respectively connected with a DC bus WB, the DC bus WB is connected with a resistive load module, the DC bus WB is connected with a contactor KM4 in series, the contactor KM4 is connected with the positive electrode of an energy storage battery pack, and the positive electrode of the energy storage battery pack is connected with the resistive load module. The positive electrode of the energy storage battery pack is further connected with the input end of an inverter through a contactor KM5. The charging and discharging device is mainly used for charging and discharging energy-saving storage batteries.

Description

Technical Field

[0001] The utility model relates to the field of new energy, and in particular to an energy-saving battery charging and discharging system. Background Art

[0002] At present, with the widespread application of batteries in all walks of life, there are more and more battery research, development and production units. The production and performance testing of batteries are inseparable from the charging and discharging process. Especially in the discharge process, some enterprises can realize the reuse of the discharged electric energy back to the grid. However, the return of electricity to the grid has high requirements. The grid connection needs to meet various technical requirements, such as insulation level, frequency synchronization, voltage regulation, etc. It also involves coordination between the government and enterprises and risk control of safety hazards, etc., which leads to most battery manufacturers or battery research and development and research institutions not to recycle the discharged electricity, resulting in a huge waste of energy. For example, the electric energy recovery device of a battery charging and discharging test equipment with announcement number CN214045051U, although it realizes the energy recovery function, its function is relatively single and does not have a discharge module. Summary of the invention

[0003] The purpose of the utility model is to provide an energy-saving battery charging and discharging system, which adopts an energy storage battery pack to charge a test battery pack to realize electric energy reuse, and switches to a power grid for power supply when the power is insufficient; when a load resistor is used as a discharge subject, a fan dissipates heat in time to protect the load resistor; different diodes and different DC / DC converter combinations can test test battery packs of different specifications.

[0004] The utility model is realized by the following technical solutions:

[0005] An energy-saving battery charging and discharging system includes a battery charging controller and a battery discharging controller, wherein the battery discharging controller is connected to a plurality of DC / DC modules, wherein the positive and negative poles of the output terminals of the plurality of DC / DC modules are respectively connected to a DC bus WB, the DC bus WB is connected to a resistive load module, the positive pole of the DC bus WB is connected in series with a contactor KM4, the contactor KM4 is connected to the positive pole of an energy storage battery pack, the positive pole of the energy storage battery pack is also connected to the input terminal of an inverter through a contactor KM5, the negative pole of the energy storage battery pack is connected to a shunt RS, and the shunt RS is respectively connected to the input terminals of a battery management system BMS and an inverter The battery management system BMS, inverter and shunt RS are all connected to the negative pole of the DC bus WB, the battery charging controller and the battery discharging controller are both connected to the test battery pack, the output end of the inverter is also connected to the L line of the input end, and the L line of the input end is also connected in series with contactor KM1 and contactor KM2, the battery charging controller and the battery discharging controller are connected to the L line between contactor KM1 and contactor KM2, contactor KM1, contactor KM2, contactor KM4 and contactor KM5 are all connected to the battery management system BMS; the battery management system BMS is responsible for the voltage and temperature collection of the energy storage battery pack.

[0006] Furthermore, the several DC / DC modules all include a diode D and a DC / DC converter, the cathode of the diode D is connected to the positive electrode of the input end of the DC / DC converter through a wire, the positive and negative electrodes of the output end of the DC / DC converter are respectively connected to the positive and negative main lines of the corresponding DC bus WB, and the anode of the diode D is connected to the battery discharge controller.

[0007] Furthermore, the resistive load module includes a load resistor R and a fan, which are connected in parallel to the positive and negative poles of the DC bus WB. The positive pole of the DC bus WB is connected to the load resistor R and the fan respectively through a contactor KM3, and the contactor KM3 is connected to the battery management system BMS.

[0008] Furthermore, the shunt RS and the fuse FU are connected in series and then connected to the negative pole of the DC bus WB.

[0009] Furthermore, the inverter and the battery management system BMS are both connected to a display screen, and the battery management system BMS is connected to the display screen via an RS485 communication protocol.

[0010] Furthermore, the DC / DC converter is connected to the battery discharge controller via RS485 communication protocol.

[0011] Furthermore, the battery charging controller and the battery discharging controller are connected to the upper computer of the charging and discharging control system through the RS485 communication protocol, and the upper computer of the charging and discharging control system, the battery charging controller and the battery discharging controller are all connected to the L line between the contactor KM1 and the contactor KM2.

[0012] Compared with the prior art, the beneficial effects of the utility model are:

[0013] 1. Through the circuit control of the utility model, the electric energy released by the test battery pack is stored in the energy storage battery pack. When the test battery pack needs to be charged again, the energy storage battery pack is preferentially used to charge the test battery pack to realize the reuse of electric energy. When the power is insufficient, it is switched to the power grid for power supply.

[0014] 2. When the test battery pack is discharged and the energy storage battery pack fails, the load resistor can ensure that the discharge continues. When the load resistor is the main body of the discharge, the fan dissipates heat in time to protect the load resistor.

[0015] 3. Through the combination of diodes and DC / DC converters and connected to the energy storage battery pack, the test battery pack can charge the energy storage battery pack according to the prescribed discharge system. Different diodes and different DC / DC converter combinations can test test battery packs of different specifications. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a system principle diagram of the utility model. DETAILED DESCRIPTION

[0017] The utility model is further described below in conjunction with the accompanying drawings.

[0018] like Figure 1As shown, embodiment 1, an energy-saving battery charging and discharging system, including a battery charging controller and a battery discharging controller, the battery discharging controller is connected to a plurality of DC / DC modules, the positive and negative output terminals of the plurality of DC / DC modules are respectively connected to the DC bus WB, the DC bus WB is connected to the resistance load module, the bus positive pole of the DC bus WB is connected in series with the contactor KM4, the contactor KM4 is connected to the positive pole of the energy storage battery pack, the positive pole of the energy storage battery pack is also connected to the input terminal of the inverter through the contactor KM5, the negative pole of the energy storage battery pack is connected to the shunt RS, the function of the shunt RS is to detect the charging and discharging current data of the energy storage battery pack, and the data is transmitted to the battery management system BMS, the shunt RS is respectively connected to the input terminal of the battery management system BMS and the inverter, the battery management system BMS, the inverter and the shunt RS are all connected to the bus negative pole of the DC bus WB, the battery charging controller and the battery discharging controller are both connected to the test battery pack, the output terminal of the inverter is also connected to the L line of the input terminal, the L line on the input terminal Contactor KM1 and contactor KM2 are also connected in series, and a battery charging controller and a battery discharging controller are connected to the L line between contactor KM1 and contactor KM2. Contactor KM1, contactor KM2, contactor KM4 and contactor KM5 are all connected to a battery management system BMS; the battery management system BMS is responsible for collecting the voltage and temperature of the energy storage battery pack, and the inverter inverts the output of the energy storage battery pack into 220V, 50Hz AC as a charging power supply for the test battery pack. The energy storage battery pack is used to store the electric energy released by the test battery pack, and then the test battery pack is charged to realize the recycling and reuse of electric energy. Since the energy storage battery pack needs to be inverted when charging the test battery pack, the terminal voltage of the energy storage battery pack is not less than 12V. The function of the DC bus is to collect the electric energy released by multiple branches on the battery discharge controller and transfer it to the energy storage battery pack or consume it in the form of heat through the load resistor R. The battery charging controller, the battery discharge controller and the battery management system BMS are all prior art.

[0019] Embodiment 2, an energy-saving battery charging and discharging system, wherein the plurality of DC / DC modules all include a diode D and a DC / DC converter, wherein the cathode of the diode D is connected to the positive electrode of the input end of the DC / DC converter through a wire, the positive and negative electrodes of the output end of the DC / DC converter are respectively connected to the positive and negative main lines of the corresponding DC bus WB, the anode of the diode D is connected to the battery discharge controller, the DC / DC converter can adjust the discharge current of the test battery group, and different diodes D and different DC / DC converter combinations can test test battery groups of different specifications; the electric energy in the test battery group is transferred to the energy storage battery group, and a single group or multiple groups can be set A combination of a diode D and a DC / DC converter, each diode D and DC / DC converter can be connected to a single battery or multiple test battery groups; the resistance load module includes a load resistor R and a fan. When the test battery group is discharged and the energy storage battery group fails, the load resistor R can ensure that the discharge continues. When the load resistor R serves as the discharge body, the fan dissipates heat in time to protect the load resistor R. The load resistor R and the fan are connected in parallel to the positive and negative poles of the bus of the DC bus WB. The positive pole of the bus of the DC bus WB is connected to the load resistor R and the fan respectively through the contactor KM3. When the contactor KM3 is closed, the load resistor R and the fan When the contactor KM3 starts working, the load resistor R and the fan stop working. The contactor KM3 is connected to the battery management system BMS. The battery management system BMS is mainly used to detect the charge state of the energy storage battery pack, automatically control the opening and closing of each contactor, and adjust the charging and discharging behavior of the energy storage battery pack; the shunt RS is connected in series with the fuse FU and connected to the negative pole of the DC bus WB. The fuse FU protects the energy storage battery pack circuit. When the system has a fault current and increases abnormally, the fuse FU will melt spontaneously and cut off the circuit; the inverter and the battery management system BMS are both connected to a display screen, which can display the battery management system BMS. MS monitors the energy storage battery pack, and the battery management system BMS is connected to the display screen through the RS485 communication protocol; the DC / DC converter is connected to the battery discharge controller through the RS485 communication protocol; the battery charging controller and the battery discharge controller are connected to the upper computer of the charge and discharge control system through the RS485 communication protocol to realize the conversion of charging and discharging operations. The upper function of the charge and discharge control system can dispatch and control the battery charging and battery discharging. The upper computer of the charge and discharge control system, the battery charging controller and the battery discharge controller are all connected to the L line between the contactor KM1 and the contactor KM2, and the rest is the same as Example 1.

[0020] The battery discharge controller is provided with one or more diodes D and a DC / DC converter combination to control the discharge current and current direction. The negative terminal of the energy storage battery pack is connected in series with the shunt RS and the fuse FU through a wire. The negative wire is connected to the negative pole of the DC bus WB and the negative input terminal of the inverter after passing through the fuse FU. The positive wire of the energy storage battery pack is divided into two branches. One branch is connected in series with the contactor KM4 and connected to the positive pole of the DC bus WB. The other branch is connected in series with the contactor KM5 and connected to the positive input terminal of the inverter. The positive power line of the battery management system BMS is directly connected to the positive terminal of the energy storage battery pack. The negative power line of the battery management system BMS is connected to the negative pole of the energy storage battery pack after passing through the fuse FU and the shunt RS. The battery management system BMS provides power for the display screen. The battery management system BMS can collect data from the shunt RS and the energy storage battery pack, monitor information such as current, voltage, temperature, and estimate the state of charge of the energy storage battery pack.

[0021] Operation logic setting:

[0022] 1) BMS settings:

[0023] The battery management system BMS is used to set the energy storage battery pack to work in a state of charge range of 20%-90%. When the state of charge range is less than or equal to 20%, external discharge is not allowed, and when the state of charge range is greater than or equal to 90%, charging is not allowed;

[0024] 2) Test battery pack charging:

[0025] When the test battery pack is connected to the charging and discharging system to run the charging program, the battery management system BMS determines the charge state of the energy storage battery pack. When the charge state of the energy storage battery pack is greater than 20%, the battery management system BMS automatically controls contactor KM1 and contactor KM4 to be disconnected, and contactor KM2 and contactor KM5 to be closed. The output of the energy storage battery pack is inverted into 220V50Hz AC power through the inverter as the power supply of the battery charging controller. When the charge state of the energy storage battery pack is less than or equal to 20%, the battery management system BMS automatically controls contactor KM1 and contactor KM4 to be closed, and contactor KM2 and contactor KM5 to be disconnected, and switches to the 220V power grid as the power supply of the battery charging controller;

[0026] 3) Test battery pack discharge:

[0027] When the test battery pack is connected to the charging and discharging system to run the discharge program, the determination of whether the energy storage battery pack is used as the system power supply is the same as the above 2). At the same time, the electric energy in the test battery pack is gathered on the DC bus WB after being combined with a number of diodes D and DC / DC converters, and finally charged into the energy storage battery pack to realize the recycling of electric energy; when the test battery pack is in the discharge state, and the battery management system BMS detects that the charge state of the energy storage battery pack reaches 90%, the battery management system BMS automatically disconnects the contactor KM4 and closes the contactor KM3, and discharges through the load resistor R.

Claims

1. An energy-saving battery charging and discharging system, comprising a battery charging controller and a battery discharging controller, characterized in that: The battery discharge controller is connected to a plurality of DC / DC modules, and the plurality of DC / DC modules are respectively connected to a DC bus WB, and the DC bus WB is connected to a resistive load module, and the DC bus WB is connected in series with a contactor KM4, and the contactor KM4 is connected to the positive electrode of the energy storage battery pack, and the positive electrode of the energy storage battery pack is also connected to the input end of the inverter through the contactor KM5, and the negative electrode of the energy storage battery pack is connected to the shunt RS, and the shunt RS is respectively connected to the input ends of the battery management system BMS and the inverter, and the battery charging controller and the battery discharge controller are both connected to the test battery pack, and the inverter is also connected to the L line of the input end, and the L line of the input end is also connected in series with contactors KM1 and KM2, and the battery charging controller and the battery discharge controller are connected to the L line between contactor KM1 and contactor KM2, and contactors KM1, KM2, KM4 and KM5 are all connected to the battery management system BMS.

2. The energy-saving battery charging and discharging system according to claim 1, characterized in that: The DC / DC modules described above all include a diode D and a DC / DC converter. The diode D is connected to the input end of the DC / DC converter. The output end of the DC / DC converter is connected to the DC bus WB. The diode D is connected to the battery discharge controller.

3. The energy-saving battery charging and discharging system according to claim 1, characterized in that: The resistive load module includes a load resistor R and a fan, which are connected in parallel to the positive and negative poles of the DC bus WB. The positive pole of the DC bus WB is connected to the load resistor R and the fan respectively through a contactor KM3, and the contactor KM3 is connected to the battery management system BMS.

4. The energy-saving battery charging and discharging system according to claim 1, characterized in that: The shunt RS and the fuse FU are connected in series and then connected to the negative pole of the DC bus WB.

5. The energy-saving battery charging and discharging system according to claim 1, characterized in that: The inverter and the battery management system BMS are both connected to a display screen, and the battery management system BMS is connected to the display screen via an RS485 communication protocol.

6. The energy-saving battery charging and discharging system according to claim 2, characterized in that: The DC / DC converter is connected to the battery discharge controller via the RS485 communication protocol.

7. The energy-saving battery charging and discharging system according to claim 1, characterized in that: The battery charging controller and the battery discharging controller are connected to the upper computer of the charge and discharge control system through the RS485 communication protocol. The upper computer of the charge and discharge control system, the battery charging controller and the battery discharging controller are all connected to the L line between the contactor KM1 and the contactor KM2.

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