Discharger for battery pack of electric vehicle

Abstract

The present invention relates to a discharger for a battery pack of an electric vehicle. This discharger for a battery pack of an electric vehicle comprises: a power module (11) having installed thereon an inverter which is electrically connected to a battery pack (BP) of the electric vehicle to discharge power of the battery pack (BP); a voltage detection module (12) which detects the voltage of the battery pack (BP) to be discharged; and a target level setting module (13) which sets a charge level of the battery pack (BP) to be discharged, wherein the power discharged from the power module (11) is transmitted to a power supply facility (PP) or stored in an energy storage system (ESS) on the basis of the level set by the target level setting module (13).

Description

Discharger for electric vehicle battery packs

[0001] The present invention relates to a discharger for an electric vehicle battery pack, and more particularly, to a discharger for an electric vehicle battery pack that maintains a constant charge level of a battery pack installed in an electric vehicle or causes it to be completely discharged.

[0002] The battery packs of electric vehicles need to be discharged for various reasons. For example, they may be discharged to a predetermined level before charging, or they may need to be discharged to maintain a predetermined charge level during storage or transportation of the electric vehicle. Furthermore, the battery packs of electric vehicles being scrapped may need to be completely discharged. Regarding battery pack discharge, Patent Publication No. 10-2006-083133 discloses a device and method for discharging batteries using Pulse Width Modulation (PWM) for battery balancing in battery packs installed in electric or hybrid vehicles. Furthermore, International Publication No. WO 2015 / 174398 discloses a battery pack, a battery system, and a discharging method that enable the appropriate discharge of excess current from within a battery pack and a system including multiple battery packs. It is advantageous for the battery pack to be discharged while mounted on the electric vehicle. Furthermore, the battery pack needs to have a structure that eliminates potential risks, such as spark generation, during the discharge process. Additionally, the discharged power needs to be processed in an appropriate manner, for example, so that it can be stored in an energy storage system or transmitted to a power supply facility. However, the prior art does not disclose a discharger with such features.

[0003] The present invention is intended to solve the problems of prior art and has the following objectives.

[0004] The purpose of the present invention is to provide a discharger for an electric vehicle battery pack that is connected to a port for charging an electric vehicle, discharges power from a battery pack mounted on the electric vehicle, and processes the discharged power in an appropriate form according to the amount of discharged power.

[0005] According to a preferred embodiment of the present invention, a discharger for an electric vehicle battery pack includes a power module electrically connected to a battery pack of an electric vehicle and having an inverter for discharging power of the battery pack; a voltage detection module for detecting a voltage of the battery pack to be discharged; and a target level setting module for setting a charge level of the battery pack to be discharged, wherein power discharged from the power module is transmitted to a power supply facility or stored in an energy storage system based on a level set by the target level setting module.

[0006] According to another suitable embodiment of the present invention, the power module is connected to the battery pack by a relay module.

[0007] According to another suitable embodiment of the present invention, the polarity of the battery pack is confirmed and the voltage of the battery pack is confirmed by the relay module.

[0008] According to another suitable embodiment of the present invention, the discharger has a spark prevention function.

[0009] According to another suitable embodiment of the present invention, the power module includes a power factor correction unit and a DC link module.

[0010] A discharger for an electric vehicle battery pack according to the present invention is connected to the inlet of an electric vehicle and discharges the battery pack mounted on the electric vehicle to a predetermined level. The discharger according to the present invention stores the power discharged from the battery pack in an energy storage system or transmits it to a power supply facility to prevent power loss. The discharger according to the present invention may be applied to charge a battery pack to a predetermined level during the storage or transportation of an electric vehicle, discharge a battery pack mounted on an electric vehicle being scrapped, discharge to maintain the charge balance of a plurality of battery packs, or discharge for similar purposes, and the present invention is not limited thereto.

[0011] FIG. 1 illustrates an embodiment of a discharger for an electric vehicle battery pack according to the present invention.

[0012] Figure 2 illustrates an embodiment of a control module of a discharger according to the present invention.

[0013] Figure 3 illustrates an embodiment of a power module of a discharger according to the present invention.

[0014] Figure 4 illustrates an embodiment of the operating process of a discharger according to the present invention.

[0015] Below, the present invention is described in detail with reference to embodiments shown in the attached drawings. However, the embodiments are for a clear understanding of the present invention and the present invention is not limited thereto. In the description below, components having the same drawing reference numerals in different drawings have similar functions and therefore will not be described repeatedly unless necessary for the understanding of the invention. Known components are briefly described or omitted, but they should not be understood as being excluded from the embodiments of the present invention.

[0016] Figure 1 illustrates an embodiment of a discharger (10) for an electric vehicle battery pack according to the present invention.

[0017] Referring to FIG. 1, a discharger (10) for an electric vehicle battery pack includes a power module (11) electrically connected to a battery pack (BP) of an electric vehicle and having an inverter installed therein for discharging power of the battery pack (BP); a voltage detection module (12) for detecting a voltage of the battery pack (BP) to be discharged; and a target level setting module (13) for setting a charge level of the battery pack (BP) to be discharged, and power discharged from the power module (11) is transmitted to a power supply facility (PP) or stored in an energy storage system (ESS) based on a level set by the target level setting module (13).

[0018] The discharger (10) can be connected to an inlet corresponding to a charging port of an electric vehicle, and can be electrically connected to a battery pack (BP) through the inlet. The discharger (10) can be connected to the inlet so as to have reverse polarity, thereby discharging to the battery pack (BP). The power discharged from the battery pack (BP) can be consumed as heat, sent to an energy storage system (ESS) to be stored, or transmitted to a power supply facility (PP) such as Korea Electric Power Corporation. For this purpose, the power module (11) can include a bi-directional inverter. For example, the bi-directional inverter can include an inductor, an IGBT (Insulated Gate Bipolar Transistor) converter, an IGBT inverter, and a capacitor connected in parallel between the IGBT converter and the IGBT inverter. The power module (11) may include various types of bidirectional inverters that can transmit the power discharged from the battery pack (BP) to the power supply facility (PP) or store it in the energy storage system (ESS), and the present invention is not limited thereto. The power module (11) may have a function of discharging the battery pack (BP) through the inlet of the electric vehicle in this way. The discharger (10) may include a voltage detection module (12), and the voltage of the battery pack (BP) may be detected by the voltage detection module (12). Optionally, the voltage of each battery module constituting the battery pack or the voltage of each battery cell forming the battery module may be detected by the voltage detection module (12). When the voltage of the battery pack (BP) is detected by the voltage detection module (12), the discharge voltage by the power module (11) may be set based on this. According to one embodiment of the present invention, the discharge level of the battery pack (BP) may be determined by the target level setting module (13).The target level setting module (13) can also determine whether to convert the power discharged from the battery pack (BP) into thermal energy for consumption, store it in the energy storage system (BP), or transmit it to the power supply facility based on the discharge level of the battery pack (BP). The discharge level can be set based on various criteria. For example, in the case of an electric vehicle for storage or transportation, the charge level of the battery pack (BP) can be set to 20 to 30% of the total, and the remaining power can be discharged. In addition, the battery pack (BP) of an electric vehicle to be scrapped can be set to be completely discharged. In this way, the target level of the battery pack (BP) can be set appropriately depending on the condition or use of each electric vehicle. In addition, the power module (11) can discharge the battery pack (BP) based on the set target level for the battery pack (BP). The target level of the battery pack (BP) can be set based on various criteria, and the present invention is not limited thereby.

[0019] Figure 2 illustrates an embodiment of a control module of a discharger according to the present invention.

[0020] Referring to Fig. 2, the power module (11) is connected to the battery pack (BP) by the relay module (25). The polarity of the battery pack (BP) is confirmed by the relay module (25), and the voltage of the battery pack (BP) is confirmed. In addition, the relay module (25) has a spark prevention function. The entire operation of the discharger can be controlled by the controller (24), and a switching mode power supply (SMPS) (22) can be installed to supply the power required for operation. The SMPS (22) can be connected to the relay module (25) or the AC power unit (AS), and can be connected in series with the power module (11). The operation of the SMPS (22) and the power module (11) can be controlled by the controller (24). The AC power unit (AS) can transmit the power discharged from the battery pack (BP) to a power supply facility. The power module (11) can be connected to the battery pack (BP) through the relay module (25), and the relay module (25) can have a function of preventing damage to the inverter disposed in the power module (11) due to the high voltage of 500 to 800 V of the battery pack (BP). For example, the size of the initial discharge current can be limited by the relay module (25). The relay module (25) can be, for example, a power relay assembly, and can have a function of checking the polarity of the battery pack (BP) and checking the voltage of the battery pack (BP). In addition, the relay module (25) can have a function of preventing spark generation, and for this purpose, the relay module (25) can include a spark prevention circuit in which a capacitor and a resistor are connected in series. For example, the spark prevention circuit can be a circuit in which a capacitor of 0.05 to 0.15 μF and a resistor of 100 to 150 Ω are connected in series, and can be connected in series to a switch or a relay.The controller (24) can communicate with the BMS (battery management system) and receive information about each battery module or each battery cell, for example, through PLC (Power Line Communication). And the received information can be displayed on the display (26). For example, the display (26) can display the voltage of the battery pack (BP), the discharge target level, the voltage of each battery module, the voltage of each battery cell, the temperature of the battery pack (BP), the SoC (State of Charge) of the battery cell, the SoH (State of Health) of the battery cell, the discharge time required for the target level, or similar information. Various information related to the discharge of the battery pack (BP) can be displayed on the display (26), and the present invention is not limited thereby. If the amount of power to be discharged from the battery pack (BP) is not suitable for transmission to the power supply facility or not suitable for storage in the energy storage system, the power discharged to the battery pack (BP) may be consumed as heat energy. For this purpose, a discharge module (23) may be installed, and the discharge module (23) may be connected to a relay module (25). The controller (24) may control the operation of the relay module (25) when the relay module (25) is connected to the power module (11) or connected to the discharge module (23), and the discharge module (23) may include a PTC (Positive Temperature Coefficient) heater. The power of the battery pack (BP) transmitted to the discharge module (23) may be consumed as heat energy or consumed in another appropriate manner, and the present invention is not limited thereby.

[0021] Figure 3 illustrates an embodiment of a power module of a discharger according to the present invention.

[0022] Referring to FIG. 3, a power module (11) includes a power factor correction unit (32) and a transformer (35). It can be connected to a battery pack (BF) and an AC power unit (AS), and a relay module can be connected between the power module (11) and the AC power unit (AS) as described above. The power module (11) includes a first filter (31) for removing noise such as radio interference due to power transmission from the AC power unit (AS); a power factor correction unit (32) connected to the first filter (31) to improve the power factor of the AC transmitted so that the power factor is close to 1.0; a DC link module (33) connected to the power factor correction unit (32); a first DC / DC converter (34) connected to the DC link module (33); a transformer (35) connected to the DC / DC converter (34); a second DC / DC converter (36) connected to the transformer (35); and a second filter (37). It can be a DC filter that removes noise from the DC power discharged from the battery pack (BP) to make the voltage at a predetermined level, and can include at least one capacitor. The power from which the noise has been removed by the second filter (37) can be made to have a stable voltage by the second DC / DC converter (36) and can be converted into a voltage suitable for transmission by the transformer (35). The power whose voltage has been converted by the transformer (35) can be stabilized by the first DC / DC converter (34), and the DC voltage can be converted into an AC voltage by the DC link module (33). For example, the DC link module (33) can include a DC link unit that smooths the DC voltage transmitted from the first DC / DC converter (34) and an inverter that smooths the DC voltage smoothed by the DC link unit into an AC voltage. The DC link module (33) can be, for example, a DC link capacitor module, but is not limited thereto.The discharged power, which is converted into AC power by the DC link module (32) and has its power factor improved by removing the pulsation and being smoothed, can be transmitted to the AC power unit (AS) via the first filter (31) after the power factor is improved by the power factor improvement unit (32). The first filter (31) can be an EMI (electromagnetic interference) filter, and the AC power unit (AS) can transmit three-phase power of AC 350 to 400 V and 60 Hz to the power supply facility. The entire operation can be controlled by the controller (24), and for example, the operation of the power factor improvement unit (32) and the first DC / DC converter (34) can be controlled, but is not limited thereto. In addition, in the presented embodiment, when the discharged power is to be stored in the energy storage system, the power transmitted from the AC power unit (AS) can be converted into DC by the converter. The storage of the discharged power in the energy storage system can be performed in various ways, and the present invention is not limited thereto.

[0023] Figure 4 illustrates an embodiment of the operating process of a discharger according to the present invention.

[0024] Referring to FIG. 4, the operating process of the discharger includes a step (P41) in which the discharger is connected to a battery pack through an inlet of an electric vehicle; a step (P42) in which the voltage of the battery pack is monitored; a step (P43) in which reverse polarity is detected and a spark prevention circuit is operated; a step (P44) in which it is confirmed whether the amount of discharge power is greater than a predetermined reference level; a step (P46) in which a target discharge level is set; a step (P47) in which it is confirmed whether a complete discharge is required; a step (P48) in which discharge is initiated; and a step (P49) in which the discharge power is transmitted to a power supply facility or stored in an energy storage system.

[0025] The connector of the discharger can be coupled to the inlet of the electric vehicle to electrically connect to the battery pack (P41), and a means for BMS (battery management system) and PLC communication can be arranged on the connector. A temperature sensor can be arranged on the connector to detect the temperature of the battery pack. Furthermore, a temperature sensor can be arranged inside the discharger to monitor the operating temperatures of internal components, such as the power module, in real time during the discharge process. If the temperature of the battery pack or the operating temperatures of internal components are excessively high, the discharge can be stopped. The voltage of the battery pack can be detected, and the voltage of the battery pack can be monitored in real time during the discharge process (P42). Furthermore, the temperature of the battery pack and the operating temperature of the discharger can be monitored in real time during the discharge process. When the connector is connected to the inlet, as described above, the relay module detects reverse polarity and activates the spark prevention circuit (P43). Thus, when the connector is connected to the inlet and discharge is enabled, the amount of power to be discharged from the battery pack can be determined. If the amount of power to be discharged does not exceed the reference level and the amount of discharged power is very small, transmitting the discharged power to the power supply facility may result in loss and may be consumed as heat (P45). In contrast, if the amount of discharged power exceeds a predetermined reference level (YES), a target discharge level corresponding to the difference between the current charge level of the battery pack and the charge level required by the battery pack can be set (P46). Optionally, it can be determined whether a complete discharge is required (P47), and for example, a complete discharge is required when an electric vehicle is to be scrapped or the battery pack is to be disposed of.If the battery pack's charge level is very low and a complete discharge is required (YES), a separate PTC (Positive Temperature Coefficient) heater can be activated (P481). Conversely, if a complete discharge is not required, the discharge is initiated by a discharger (P48), and the discharger can transmit the discharged power to a power supply facility or energy storage system through the process described above (P49). The power discharge of the battery pack can be performed in various ways, and the present invention is not limited thereto.

[0026] While the present invention has been described in detail above with reference to the presented embodiments, those skilled in the art will appreciate that various modifications and variations can be made without departing from the technical spirit of the present invention. The present invention is not limited by such modifications and variations, but is instead limited by the appended claims.

[0027] The present invention can be used for discharging a battery pack of an electric vehicle.

Claims

1. A power module (11) electrically connected to a battery pack (BP) of an electric vehicle and having an inverter installed thereon to discharge power from the battery pack (BP); A voltage detection module (12) that detects the voltage of a battery pack (BP) that is being discharged; and Includes a target level setting module (13) that sets the charge level of the battery pack (BP) to be discharged, A discharger for an electric vehicle battery pack, characterized in that the power discharged from the power module (11) is transmitted to a power supply facility (PP) or stored in an energy storage system (ESS) based on a level set by a target level setting module (13).

2. A discharger for an electric vehicle battery pack, characterized in that in claim 1, the power module (11) is connected to the battery pack (BP) by a relay module (25).

3. A discharger for an electric vehicle battery pack, characterized in that, in claim 1, the polarity of the battery pack (BP) is confirmed and the voltage of the battery pack (BP) is confirmed by a relay module (25).

4. A discharger for an electric vehicle battery pack, characterized in that it has a spark prevention function according to claim 1.

5. In claim 1, a power module (11) is a discharger for an electric vehicle battery pack including a power factor improvement unit (32) and a DC link module (33).

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