Power supply circuit and electric automobile
By designing a power supply circuit including high-voltage power battery, DC-DC conversion module, lithium battery module, supercapacitance module and load module, the problem of insufficient discharge performance of lithium batteries at low temperatures is solved, and a large-rate current is provided for the vehicle at low temperatures, and the system is quickly restored through fast charging capabilities.
Patent Information
- Application Number
- CN202420324274.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-02-21
- Publication Date
- 2025-03-04
- Estimated Expiration
- 2034-02-21
AI Technical Summary
Lithium batteries cannot provide the same low-temperature discharge performance as lead-acid batteries under low temperature conditions, resulting in the system being unable to provide external energy at 5C discharge rate under low temperature -40℃.
A power supply circuit is designed, including a high-voltage power battery, a DC-DC conversion module, a lithium battery module, a supercapacitance module and a load module. At low temperatures, the lithium battery module cuts out of the power supply system, and only the supercapacitor module provides a large-rate current. When no large current is needed, the lithium battery module cuts back to the power supply system and replenishes the energy of the supercapacitor module.
It realizes the provision of large-rate current for the entire vehicle at low temperature, solves the problem of insufficient discharge performance of lithium batteries at low temperatures, and the fast charging capability of the supercapacitor module allows the system to recover quickly without requiring large currents.
Smart Images
Figure CN222563531U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of new energy vehicles, and in particular to a power supply circuit and an electric vehicle. Background Art
[0002] The low-voltage power supply module of the entire vehicle is generally powered by lead-acid batteries. The advantage of lead-acid batteries is that they have a high discharge rate at low temperatures, that is, they can provide a large current for the entire vehicle at low temperatures. However, lead-acid batteries also have many disadvantages, such as large size, heavy weight, and containing toxic heavy metals. With the deepening of vehicle intelligence and the extreme weight reduction of the entire vehicle, a number of 12V low-voltage lithium battery manufacturers have emerged on the market, providing 12V low-voltage lithium batteries to gradually replace lead-acid batteries. Although lead-acid batteries still have a huge market share, it is inevitable that lithium batteries will replace lead-acid batteries over time.
[0003] In related technologies, under low temperature conditions, such as at -40°C, if a lithium battery is discharged at 5C (C: discharge rate), the system cell voltage is immediately pulled down to the system protection threshold, that is, at a low temperature of -40°C and a 5C discharge rate, the system cannot provide energy to the outside world. This gives rise to new problems. Lithium batteries are replacing lead-acid batteries, but lithium batteries do not have the low-temperature discharge performance of lead-acid batteries. This is a difficulty that needs to be solved at present, or in other words, on the road to lithium batteries replacing lead-acid batteries, the low-temperature discharge rate is an inevitable issue that lithium battery suppliers need to consider first. Utility Model Content
[0004] The purpose of the present utility model is to provide a power supply circuit and an electric vehicle to solve the technical problem raised in the above background technology: in the prior art, lithium batteries are replacing lead-acid batteries, but lithium batteries do not have the low-temperature discharge performance of lead-acid batteries.
[0005] To achieve the above-mentioned purpose, according to one aspect of the present disclosure, a power supply circuit is provided, which includes: a high-voltage power battery, a DC-DC conversion module, a lithium battery module, a super-capacity module and a load module, wherein the high-voltage power battery is connected to the DC-DC conversion module, the DC-DC conversion module is connected to the lithium battery module, the super-capacity module is connected in parallel with the lithium battery module, and the lithium battery module and the super-capacity module are both connected to the load module.
[0006] In some possible implementations, the power supply circuit further includes: a comparator module and a main control module, the input end of the comparator module is connected to the output end of the super-capacitor module and the lithium battery module, the output end of the comparator module is connected to the main control module, and the main control module is connected to the lithium battery module.
[0007] In some possible implementations, the lithium battery module is provided with a discharge MOS unit, and the main control module is connected to the discharge MOS unit.
[0008] In some possible implementations, the comparator module includes an operational amplifier U4A and an operational amplifier U4B, the positive input and positive output of the operational amplifier U4A are connected to the positive and negative poles of the super-capacitor module and the lithium battery module, the output of the operational amplifier U4A is connected to the positive input of the operational amplifier U4B, the negative input of the operational amplifier U4B is connected to a feedback network, and the output of the operational amplifier U4B is connected to the main control module.
[0009] In some possible implementations, the lithium battery module includes a 12V lithium battery.
[0010] In some possible implementations, the supercapacitor module is composed of several supercapacitors.
[0011] According to another aspect of the present disclosure, the present invention further provides an electric vehicle, comprising a power supply circuit as described in the above aspect.
[0012] The power supply circuit provided by the embodiment of the present utility model includes a high-voltage power battery, a DC-DC conversion module, a lithium battery module, an ultra-capacity module and a load module. When the entire vehicle needs a high-rate discharge at low temperatures, the lithium battery module is cut out of the power supply system. At this time, only the ultra-capacity module provides this high-rate current. When the entire vehicle does not need a high current, the lithium battery module is switched back to the power supply system. While supplying power to the load module, it also replenishes the energy of the ultra-capacity module. The ultra-capacity module has a charging speed of about 1 minute to achieve full charge from 0V. This design scheme can provide a high-rate current for the entire vehicle at low temperatures. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 This is a module block diagram of an embodiment of the utility model;
[0014] Figure 2 This is a module block diagram of an embodiment of the utility model;
[0015] Figure 3 This is a schematic diagram of the comparator module circuit according to an embodiment of the present invention.
[0016] Explanation of the accompanying drawings: 100, high-voltage power battery; 200, DC-DC conversion module; 300, lithium battery module; 400, super-capacity module; 500, load module; 600, comparator module; 700, main control module. DETAILED DESCRIPTION
[0017] The overall idea of the technical solution provided by this utility model is as follows:
[0018] See also Figure 1 A power supply circuit includes: a high-voltage power battery 100, a DC-DC conversion module 200, a lithium battery module 300, an ultra-capacity module 400 and a load module 500, wherein the high-voltage power battery 100 is connected to the DC-DC conversion module 200, the DC-DC conversion module 200 is connected to the lithium battery module 300, the ultra-capacity module 400 is connected to the lithium battery module 300 in parallel, and the lithium battery module 300 and the ultra-capacity module 400 are both connected to the load module 500.
[0019] Among them, the high-voltage power battery 100 is the main energy storage device of the power supply circuit, which is usually composed of multiple battery cells connected in series. The high-voltage power battery 100 is used to output high-voltage direct current. The DC-DC conversion module 200 is used to convert the high-voltage direct current output by the high-voltage power battery 100 into corresponding low-voltage direct current to meet the needs of the lithium battery module 300 and the super-capacitor module 400. The lithium battery module 300 is usually composed of multiple lithium battery cells connected in series. The lithium battery module 300 is used for low-voltage power supply. The super-capacitor module 400 is usually composed of multiple supercapacitors for providing transient power support. The load module 500 is various equipment or electronic devices that require power support. In actual use, the high-voltage power battery 100 outputs high-voltage direct current through The DC-DC conversion module 200 converts the DC power into low-voltage direct current, which is then supplied to the lithium battery module 300 and the super-capacity module 400. The load module 500 obtains power support from the lithium battery module 300 and the super-capacity module 400 to meet its operating requirements. When the entire vehicle requires a high-rate discharge at low temperatures, the lithium battery module 300 is disconnected from the power supply system. At this time, only the super-capacity module 400 provides this high-rate current. When the entire vehicle does not require a high current, the lithium battery module 300 is switched back to the power supply system, supplying power to the load module 500 while also replenishing the energy of the super-capacity module 400. The super-capacity module 400 has a charging speed of about 1 minute to achieve full charge from 0V. This design scheme can provide a high-rate current for the entire vehicle at low temperatures.
[0020] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0021] For further information, see Figure 2The power supply circuit further includes: a comparator module 600 and a main control module 700, wherein the input end of the comparator module 600 is connected to the output end of the super-capacity module 400 and the lithium battery module 300, the output end of the comparator module 600 is connected to the main control module 700, and the main control module 700 is connected to the lithium battery module 300, wherein the input end of the comparator module 600 is used to obtain the current of the output end of the super-capacity module 400 and the lithium battery module 300, and to determine whether the current is large. When the current is greater than the set value, the comparator module 600 outputs a high level to the main control module 700. The main control module 700 will make a judgment based on the current temperature. If the system is in a low temperature state, the main control module 700 will immediately cut the lithium battery module 300 out of the power supply system. At this time, only the super-capacity module 400 in the system provides high current for the system. When the system does not need high current, the main control module 700 will connect the lithium battery module 300 to the power supply system and the super-capacity module 400 to power low-voltage electrical equipment.
[0022] Furthermore, the lithium battery module 300 is provided with a discharge MOS unit, and the main control module 700 is connected to the discharge MOS unit. The main control module 700 controls the lithium battery module 300 to switch in and out of the power supply system by controlling the discharge MOS unit. Specifically, when the main control module 700 needs to switch the lithium battery module 300 out of the power supply system, it sends a control signal to the discharge MOS unit, thereby turning off the discharge MOS unit, so that the lithium battery module 300 stops providing power support to the load module 500. When the lithium battery module 300 needs to be reconnected to the system, the main control module 700 sends a control signal to turn on the discharge MOS unit, thereby allowing the lithium battery module 300 to provide power support to the load module 500.
[0023] For further information, see Figure 3 The comparator module 600 includes an operational amplifier U4A and an operational amplifier U4B, the positive input and positive output of the operational amplifier U4A are connected to the positive and negative electrodes of the super-capacitor module 400 and the lithium battery module 300, the output of the operational amplifier U4A is connected to the positive input of the operational amplifier U4B, the negative input of the operational amplifier U4B is connected to the feedback network, and the output of the operational amplifier U4B is connected to the main control module 700, wherein the operational amplifier U4A obtains and amplifies the current information of the super-capacitor module 400 and the lithium battery module 300 through the positive input and positive output, and the positive input of the operational amplifier U4B obtains the current information from the operational amplifier U4A and compares it with the set value preset in the feedback network. When the current is greater than the set value, the output of the operational amplifier U4B outputs a high level to the main control module 700.
[0024] Furthermore, the lithium battery module 300 includes a 12V lithium battery.
[0025] Furthermore, the supercapacitor module 400 is composed of several supercapacitors. Specifically, supercapacitors are mainly used in wind power blade frequency modulation in the industry. Supercapacitors have a high rate discharge at low temperatures and a cycle life of 1 million+. However, the energy stored in supercapacitors is far less than that of lithium batteries. The capacity of lithium batteries currently under development by competitors on the market is 20Ah. When using a 1500F supercapacitor with the same voltage as a 12V lithium battery, the capacity of the supercapacitor system is about 0.3Ah. It is not suitable for use in scenarios with high energy requirements. How to make the product have both the energy of lithium batteries and the low-temperature discharge capability of supercapacitors, so that it can perfectly replace lead-acid batteries, thus solving the pain points of lithium battery manufacturers. Since the supercapacitor module 400 has been developed at low temperatures, A large current is provided. When the lithium battery module 300 is connected to the system, it is bound to charge the super-capacity module 400. Two factors need to be considered here, namely: charging time and damage caused by the charging current to the super-capacity module 400. Since the super-capacity module 400 is a supercapacitor with a lifespan of 100W+ and a high-rate charge and discharge characteristic, the size of the charging current is basically negligible for the super-capacity module. Through actual measurement, we found that when the charging current is 15A, the super-capacity module only takes 65S to fully charge from 0V; even if the current is reduced to 10A, the super-capacity module only takes 95S to fully charge from 0V. To verify the effectiveness of this design, we conducted actual measurements. When the circuit current exceeds the set threshold, the D I_SCP_EN_DSGMOS outputs a high level to the MCU, which then controls the discharge MOS to disconnect. The time from the current exceeding the threshold to the disconnection of the discharge MOS is measured to be less than 50uS. Within this time, the response completely solves the discharge rate problem of 12V lithium batteries at low temperatures.
[0026] An embodiment of the present utility model further provides an electric vehicle, comprising a power supply circuit as in the aforementioned embodiment. Various variations and specific embodiments in the aforementioned embodiment are also applicable to the electric vehicle of this embodiment. Through the aforementioned detailed description of a power supply circuit, those skilled in the art can clearly understand the implementation method of the electric vehicle in this embodiment. For the sake of brevity of the specification, it will not be described in detail here.
[0027] In summary, the utility model provides a power supply circuit. In actual use, the high-voltage power battery 100 outputs high-voltage direct current, which is converted into low-voltage direct current through the DC-DC conversion module 200 and supplied to the lithium battery module 300 and the super-capacity module 400; the load module 500 obtains power support from the lithium battery module 300 and the super-capacity module 400 to meet its operating requirements. When the entire vehicle needs a high-rate discharge at low temperatures, the lithium battery module 300 is cut out of the power supply system. At this time, only the super-capacity module 400 provides this high-rate current. When the entire vehicle does not need a high current, the lithium battery module 300 is switched back to the power supply system, and while supplying power to the load module 500, it also replenishes the energy of the super-capacity module 400. The super-capacity module 400 has a charging speed of about 1 minute to achieve full charge from 0V.
[0028] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.
[0029] Obviously, those skilled in the art may make various changes and modifications to the embodiments of the present invention without departing from the spirit and scope of the embodiments of the present invention. Thus, if such modifications and variations of the embodiments of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is intended to include such modifications and variations.
Claims
1. A power supply circuit, characterized in that: include: A high-voltage power battery, a DC-DC conversion module, a lithium battery module, an ultra-capacity module and a load module, wherein the high-voltage power battery is connected to the DC-DC conversion module, the DC-DC conversion module is connected to the lithium battery module, the ultra-capacity module is connected to the lithium battery module in parallel, and the lithium battery module and the ultra-capacity module are both connected to the load module.
2. A power supply circuit according to claim 1, characterized in that: Also includes: A comparator module and a main control module, wherein the input end of the comparator module is connected to the output ends of the supercapacitor module and the lithium battery module, the output end of the comparator module is connected to the main control module, and the main control module is connected to the lithium battery module.
3. A power supply circuit according to claim 2, characterized in that: The lithium battery module is provided with a discharge MOS unit, and the main control module is connected to the discharge MOS unit.
4. A power supply circuit according to claim 2, characterized in that: The comparator module includes an operational amplifier U4A and an operational amplifier U4B, the positive input and positive output of the operational amplifier U4A are connected to the positive and negative electrodes of the super-capacitor module and the lithium battery module, the output of the operational amplifier U4A is connected to the positive input of the operational amplifier U4B, the negative input of the operational amplifier U4B is connected to a feedback network, and the output of the operational amplifier U4B is connected to the main control module.
5. A power supply circuit according to claim 1, characterized in that: The lithium battery module includes a 12V lithium battery.
6. A power supply circuit according to claim 1, characterized in that: The supercapacitor module is composed of a plurality of supercapacitors.
7. An electric vehicle, characterized in that: Comprising a power supply circuit as described in any one of claims 1-6.