Battery pulse self-heating circuit
By using a transformer in the circuit design to match the internal resistance of the battery with the internal resistance of the power device in the lithium-ion power battery, efficient heating under low temperature conditions is achieved, solving the problems of low heating efficiency and high cost in the existing technology, and improving heating uniformity and power utilization.
Patent Information
- Application Number
- CN202422918131.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-28
- Publication Date
- 2025-12-23
- Estimated Expiration
- 2034-11-28
AI Technical Summary
Existing lithium-ion power batteries have low heating efficiency at low temperatures. External heating methods are limited by temperature difference and power, while self-heating methods require high-cost, low-resistance devices.
The internal resistance of the battery is matched with that of the power device by a transformer, so that the internal resistance of the power device is one order of magnitude lower than that of the battery. The heating process is controlled by a pulse signal generator.
It improves heating uniformity and temperature rise rate, reduces the heat demand of power devices, and improves the utilization efficiency of heating power.
Smart Images
Figure CN223712863U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of battery management technology, specifically relating to a battery pulse self-heating circuit. Background Technology
[0002] The performance of current mainstream lithium-ion power batteries is significantly affected by temperature. Generally, the optimal operating range for lithium-ion power batteries is 20°C to 40°C. Under low-temperature conditions, the conductivity of the electrolyte decreases, reducing lithium-ion activity and causing a significant reduction in capacity and voltage. In particular, charging at cell temperatures below 0°C can easily lead to the deposition of metallic lithium on the negative electrode, causing a reaction between the metallic lithium and the electrolyte and resulting in irreversible damage to the battery's capacity. To address this issue, automotive power batteries are typically designed with heating systems to ensure that the cell temperature is above 0°C at the start of charging.
[0003] Currently, battery heating methods are divided into two categories: external heating and self-heating. External heating methods mainly involve heating film heating and PTC heating. The problem with external heating is that heat needs to be transferred from an external heating source to the battery cell. This heat transfer inevitably leads to temperature gradients and differences, thus limiting heating power and temperature rise rate, increasing low-temperature charging time, and affecting the user experience. Self-heating methods feature uniform heating and rapid temperature rise, but require the external circuit loop to have a very low resistance value (more than an order of magnitude lower than the battery's internal resistance); otherwise, the heating power utilization rate is low (see...). Figure 1 If switching devices and diodes are to achieve a resistance one order of magnitude lower than that of the battery, the cost of semiconductor devices will be relatively high. Utility Model Content
[0004] To address the aforementioned problems, this invention proposes a battery pulse self-heating circuit, which uses a transformer to match the internal resistance of the battery with the internal resistance of the power device, with the battery's internal resistance bearing most of the overcurrent heat generation.
[0005] To achieve the above-mentioned technical objectives and effects, this utility model is implemented through the following technical solution:
[0006] A battery pulse self-heating circuit includes: a pulse signal generator, a power switch, a series oscillation circuit, a transformer, a parallel oscillation circuit, and an inductor circuit;
[0007] The pulse signal generator is connected to the power switch and is used to control the power switch to be in an on or off state.
[0008] The first end of the series oscillation circuit is connected to the first end of the secondary coil of the transformer, and its second end is used to connect to the positive terminal of the battery.
[0009] The second end of the secondary coil of the transformer is grounded and used to be connected with the negative pole of the battery, and the number of turns of the secondary coil is less than the number of turns of the primary coil.
[0010] The first end of the parallel oscillation circuit is connected with the first end of the primary coil of the transformer and then connected with the positive pole of the power switch, and the second end of the parallel oscillation circuit is connected with the second end of the primary coil and then grounded.
[0011] The first end of the inductive circuit is used to be connected with the positive pole of the battery, and the second end of the inductive circuit is connected with the positive pole of the power switch.
[0012] The negative pole of the power switch is grounded.
[0013] The above technical solution realizes the matching of the internal resistance of the battery and the internal resistance of the power device by using the transformer, so that the internal resistance of the power device is at least one order of magnitude lower than the internal resistance of the battery, and the internal resistance of the battery bears more than 90% of the overcurrent heat.
[0014] Optionally, the turns ratio of the primary coil to the secondary coil of the transformer is greater than or equal to a set threshold, so that the internal resistance of the power switch is at least one order of magnitude lower than the internal resistance of the battery after being converted to the secondary circuit by the transformer.
[0015] In the specific implementation process, the turns ratio of the primary coil to the secondary coil can be set to about 10, so that the internal resistance of the power switch, which is originally the same order of magnitude as the internal resistance of the battery, becomes one tenth of the original, achieving the goal of the internal resistance of the power switch being one order of magnitude lower than the internal resistance of the battery, and effectively reducing the heat of the power switch.
[0016] Optionally, the resonance frequency of the series oscillation circuit is consistent with the resonance frequency of the parallel oscillation circuit.
[0017] The above technical solution sets the resonance frequency of the series oscillation circuit to be consistent with the resonance frequency of the parallel oscillation circuit, so that a larger oscillation current can be excited in the secondary circuit under the excitation of the resonance frequency of the secondary coil, and a large amount of heat can be generated on the internal resistance of the battery.
[0018] Optionally, the series oscillation circuit comprises a first inductor and a first capacitor connected in series.
[0019] The above technical solution sets the series oscillation circuit to comprise a first inductor and a first capacitor connected in series, to achieve the technical effect of direct current isolation and resonance.
[0020] Optionally, the parallel oscillation circuit comprises a second inductor and a second capacitor connected in parallel.
[0021] The parallel oscillation circuit is arranged to include a second inductor and a second capacitor in parallel, is used for screening the fundamental frequency of the pulse signal, and is sent into the primary coil of the transformer.
[0022] Optionally, the inductive circuit includes a third inductor.
[0023] The inductive circuit is arranged to include a third inductor, and is used for limiting the current of the primary loop of the transformer.
[0024] Optionally, the third inductor is connected in parallel with a first diode.
[0025] The first diode is used for releasing the induced current of the third inductor, so as to prevent the power switch from being broken down.
[0026] Compared with the prior art, the battery pulse self-heating circuit has the following beneficial effects:
[0027] The battery pulse self-heating circuit in the utility model realizes the matching of the internal resistance of the battery and the internal resistance of the power device by using the transformer, so that the internal resistance of the power device is at least one order of magnitude lower than the internal resistance of the battery, the battery internal resistance bears most of the overcurrent heat, the requirement for the resistance of the power device in the on state can be reduced, and the utilization efficiency of the heating power can be improved.
[0028] In the utility model, the turns ratio of the primary coil and the secondary coil of the transformer is greater than or equal to a set threshold value, so that the resistance value of the internal resistance of the power switch after being converted to the secondary loop through the transformer is at least one order of magnitude lower than the resistance value of the internal resistance of the battery, and finally the battery internal resistance bears more than 90% of the overcurrent heat.
[0029] In the utility model, the parallel oscillation circuit is arranged on the primary side of the transformer, is used for screening the fundamental frequency of the pulse; and the series oscillation circuit is arranged on the secondary side of the transformer, is used for realizing the direct current isolation and resonance. BRIEF DESCRIPTION OF DRAWINGS
[0030] In order to make the content of the utility model more easily and clearly understood, the utility model will be further described in detail below according to specific embodiments and in combination with the drawings, wherein:
[0031] Figure 1 The circuit adopted by the self-heating method in the prior art;
[0032] Figure 2 The circuit schematic diagram of the battery pulse self-heating circuit of one embodiment of the utility model;
[0033] Figure 3 The circuit adopted by the self-heating method in the prior art; Figure 2The simulation result schematic diagram after each component is assigned with reasonable parameters is shown.
[0034] Wherein: R1-first resistance, R2-second resistance, R3-third resistance, R4-fourth resistance, R5-fifth resistance, D1-first diode, L1-first inductor, C1-first capacitor, L2-second inductor, C2-second capacitor, L3-third inductor, B1-battery, A1-first AC ammeter, A2-second AC ammeter, A3-third AC ammeter, P1-pulse signal generator, CS1-power switch, TR-transformer. DETAILED DESCRIPTION
[0035] In order to make the purpose, technical scheme and advantages of the utility model more clearly, the following will be further described in detail. It should be understood that the specific embodiments described herein are only used to explain the utility model, and are not used to limit the protection scope of the utility model.
[0036] In the description of the utility model patent, it should be pointed out that the terms "upper", "lower", "left", "right", "horizontal" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the utility model patent and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore it cannot be understood as a limitation of the utility model patent.
[0037] In the description of the utility model patent, it should be pointed out that unless otherwise specified and limited, the terms "mounting", "connecting", "connecting" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected, it can be mechanically connected, or it can be electrically connected, it can be directly connected, or indirectly connected through an intermediate medium, it can be the communication between two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood through specific circumstances.
[0038] The application principle of the utility model will be described in detail below in combination with the drawings.
[0039] As Figure 2 As shown in the utility model, a battery pulse self-heating circuit is provided, which comprises: a pulse signal generator P1, a power switch CS1, a series oscillation circuit, a transformer TR, a parallel oscillation circuit and an inductor circuit.
[0040] The pulse signal generator P1 is connected with the power switch CS1, which is used to control the power switch CS1 to be in the on or off state.
[0041] The first end of the series oscillation circuit is connected to the first end of the secondary coil of the transformer TR, and its second end is used to connect to the positive terminal of the battery B1.
[0042] The second terminal of the secondary coil of the transformer TR is grounded and used to connect to the negative terminal of the battery B1. The number of turns of the secondary coil is less than the number of turns of the primary coil.
[0043] The first end of the parallel oscillation circuit is connected to the first end of the primary coil of the transformer TR and then to the positive terminal of the power switch CS1. Its second end is connected to the second end of the primary coil and then grounded.
[0044] The first end of the inductor circuit is connected to the positive terminal of the battery B1, and the second end is connected to the positive terminal of the power switch CS1.
[0045] The negative terminal of the power switch CS1 is grounded.
[0046] The above technical solution utilizes a transformer TR to achieve the relationship between the internal resistance of battery B1 (i.e., the first resistor R1) and the internal resistance of the power device (i.e., the first resistor R1). Figure 2 Matching with the fifth resistor (R5) ensures that the internal resistance of the power device is lower than that of the battery, allowing the battery's internal resistance to handle most of the overcurrent heat. This reduces the requirement for the internal resistance of the power device in its on-state and improves the efficiency of power utilization. Heating is achieved by emitting a pulse signal from a pulse signal source; to stop heating, the pulse signal source is turned off.
[0047] In one specific embodiment of the present invention, the turns ratio of the primary coil to the secondary coil of the transformer TR is greater than or equal to a set threshold, so that the internal resistance of the power switch CS1, after being referred to the secondary circuit through the transformer, is at least one order of magnitude lower than the internal resistance of the battery B1.
[0048] In the specific implementation of the above technical solution, the turns ratio of the primary coil to the secondary coil can be set to approximately 10. This reduces the internal resistance of the power switch CS1, which was originally on the same order of magnitude as the internal resistance of battery B1, to one-tenth of its original value. This achieves the goal of making the internal resistance of the power switch CS1 one order of magnitude lower than that of battery B1. Since the battery's internal resistance handles over 90% of the overcurrent heat generation, this effectively reduces the heat generation of the power switch CS1. In specific implementations, the turns ratio of the primary coil to the secondary coil can also be other values, adapted to actual needs.
[0049] In one specific embodiment of the present invention, the resonant frequency of the series oscillation circuit is the same as the resonant frequency of the parallel oscillation circuit.
[0050] The technical scheme sets the resonance frequency of the series oscillation circuit and the resonance frequency of the parallel oscillation circuit to be consistent, so that a larger oscillation current can be excited in the secondary loop under excitation of the secondary coil resonance frequency, and a large amount of heat is generated on the internal resistance of the battery B1.
[0051] In a specific embodiment of the embodiment of the application, the series oscillation circuit comprises a first inductor L1 and a first capacitor C1 connected in series.
[0052] The technical scheme sets the series oscillation circuit to comprise a first inductor L1 and a first capacitor C1 connected in series, so as to achieve the technical effect of direct current isolation and resonance.
[0053] In a specific embodiment of the embodiment of the application, the parallel oscillation circuit comprises a second inductor L2 and a second capacitor C2 connected in parallel.
[0054] The technical scheme sets the parallel oscillation circuit to comprise a second inductor L2 and a second capacitor C2 connected in parallel, so as to filter the fundamental frequency of the pulse signal and send it to the primary coil of the transformer TR.
[0055] In a specific embodiment of the embodiment of the application, the inductor circuit comprises a third inductor L3, and the internal resistance of the third inductor L3 is a resistor R4.
[0056] The technical scheme sets the inductor circuit to comprise a third inductor L3, so as to limit the current of the primary loop of the transformer TR.
[0057] In a specific embodiment of the embodiment of the application, a first diode D1 is connected in parallel with the third inductor L3, and the internal resistance of the first diode D1 is a resistor R3.
[0058] The technical scheme sets the first diode D1 to release the induced current of the third inductor L3, so as to prevent the power switch CS1 from being broken down and improve the safety of the battery pulse self-heating circuit.
[0059] In the implementation process, the battery B1 pulse self-heating circuit further comprises a second AC current meter A2 connected in series with the third inductor L3. The technical scheme can be considered as a wire with no internal resistance, which is used to observe the current data in the circuit in real time.
[0060] In the implementation process, the battery B1 pulse self-heating circuit further comprises a first AC current meter A1, one end of which is connected to the second end of the secondary coil, and the other end is used to be connected to the negative electrode of the battery B1.
[0061] In the above technical solution, the first AC ammeter A1 can be considered as a wire with no internal resistance, used to observe the current data in the circuit in real time.
[0062] In the specific implementation process, the battery B1 pulse self-heating circuit also includes a third AC ammeter A3. One end of the third AC ammeter A3 is connected to the first end of the primary coil of the transformer TR, and the other end is connected to the first end of the parallel oscillation circuit.
[0063] In the above technical solution, the third AC ammeter A3 can be considered as a wire with no internal resistance, used to observe the current data in the circuit in real time.
[0064] right Figure 2 The components were assigned appropriate parameters and simulation results were obtained as follows: Figure 3 As shown. From Figure 3 As can be seen, based on the pulse self-heating circuit of battery B1 proposed in this utility model, the heating power of battery B1 is 705W (the formula for calculating the heating power is I). 2 The remaining components have a heating power of 26W, and the effective utilization rate of the heating power is 96%.
[0065] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.
Claims
1. A battery pulse self-heating circuit, characterized in that, include: Pulse signal generator, power switch, series oscillator circuit, transformer, parallel oscillator circuit and inductor circuit; The pulse signal generator is connected to the power switch and is used to control the power switch to be in an on or off state. The first end of the series oscillation circuit is connected to the first end of the secondary coil of the transformer, and its second end is used to connect to the positive terminal of the battery. The second terminal of the secondary coil of the transformer is grounded and used to connect to the negative terminal of the battery. The number of turns of the secondary coil is less than the number of turns of the primary coil. The first end of the parallel oscillation circuit is connected to the first end of the primary coil of the transformer and then to the positive terminal of the power switch; the second end is connected to the second end of the primary coil and then grounded. The first end of the inductor circuit is connected to the positive terminal of the battery, and the second end is connected to the positive terminal of the power switch. The negative terminal of the power switch is grounded.
2. The battery pulse self-heating circuit according to claim 1, characterized in that: The turns ratio of the primary coil to the secondary coil of the transformer is greater than or equal to a set threshold, so that the internal resistance of the power switch, after being referred to the secondary circuit through the transformer, is at least one order of magnitude lower than the internal resistance of the battery.
3. The battery pulse self-heating circuit according to claim 1, characterized in that: The resonant frequency of the series oscillating circuit is the same as that of the parallel oscillating circuit.
4. The battery pulse self-heating circuit according to claim 1, characterized in that: The series oscillation circuit includes a first inductor and a first capacitor connected in series.
5. A battery pulse self-heating circuit according to claim 1, characterized in that: The parallel oscillation circuit includes a second inductor and a second capacitor connected in parallel.
6. A battery pulse self-heating circuit according to claim 1, characterized in that: The inductor circuit includes a third inductor.
7. A battery pulse self-heating circuit according to claim 6, characterized in that: A first diode is connected in parallel with the third inductor to release the induced current of the third inductor.