Cold environment battery pulse current equalization self-heating method based on mutual inductance transformer

Abstract

The invention provides a cold environment battery pulse current equalization self-heating method based on a mutual inductance transformer, particularly belongs to the technical field of power electronics, and realizes pulse current type heating of any two monomers of a plurality of series battery packs by using a mutual inductance equalizer of the battery packs. The pulse current type heating system can quickly, uniformly and efficiently heat the lithium ion battery, meanwhile, the battery is heated by using the equalizer, and two functions are realized through one system to reduce the cost, so that the heating cost is reduced. The device comprises a diode assembly, an electrode assembly and an inductor assembly, and further comprises a one-way transformer. The diode assembly and the inductor assembly are connected in series to form an equalization unit, the equalization unit and the electrode assembly are electrically connected to form a mutual inductance equalizer, a heating strategy of the energy storage power supply is realized by using the mutual inductance equalization system, and internal heating of the energy storage battery is realized.

Description

Technical Field

[0001] The invention relates to a cold environment battery pulse current balancing self-heating method based on a mutual inductance transformer, and specifically belongs to the technical field of power electronics. Background Art

[0002] Energy and environmental issues have become the focus of global attention. Various new energy technologies are emerging one after another, and higher requirements are also put forward for energy storage technology. Voltage-type energy storage power supply components based on power batteries usually have advantages such as high power density, safety and cleanliness, and have been widely used in technical fields that require energy storage, such as electric vehicles, space power supplies, and power pulse devices. However, in low temperature environments, the discharge performance and battery capacity of power batteries will deteriorate, thereby reducing the cycle life of the battery. Therefore, the use of effective heating technology in low temperature environments is one of the key technologies for the practical application of power batteries.

[0003] At present, the heating technologies of power batteries at home and abroad can be roughly divided into the following two categories:

[0004] The first type is to use an external heat source to heat the power battery;

[0005] The second type is to use the characteristic that the power battery will generate heat when charging and discharging, select appropriate power battery charging and discharging parameters, and realize internal heating of the power battery;

[0006] The first type of heating technology has the advantages of simple structure and low cost. However, due to the slow thermal conductivity of the battery body, the battery core heats up slowly, and part of the heat generated by the external heater is dissipated in the surrounding environment, resulting in low heating efficiency.

[0007] The second type of heating technology uses the injection of AC pulse current into the battery cell to directly heat the battery cell. Therefore, it has the advantages of rapid heating and high efficiency, but the structure of the additional heating system required is more complex and more expensive than the first type. Summary of the invention

[0008] The purpose of the present invention is to provide a cold environment battery pulse current balanced self-heating method based on a mutual inductance transformer to solve the problem of difficulty in implementing a pulse current heating system for a series energy storage battery group in a cold environment and high cost.

[0009] In order to solve the above technical problems, the technical solution adopted by the present invention is: the system includes a diode assembly, an electrode assembly and an inductor assembly, and also includes a unidirectional transformer;

[0010] The electrode assembly includes a first electrode, a second electrode, a third electrode, a fourth electrode, a fifth electrode and a sixth electrode;

[0011] The first electrode is electrically connected to the first diode, the second diode and the first inductor in sequence, the second electrode is electrically connected to the first inductor, the third diode and the fourth diode in sequence, the second electrode is also electrically connected to the fifth diode, the sixth diode and the second inductor in sequence, the third electrode is electrically connected to the seventh diode, the eighth diode and the third inductor in sequence, the third electrode is also electrically connected to the second inductor, the tenth diode and the eleventh diode in sequence, the fourth electrode is electrically connected to the third inductor, the twelfth diode and the thirteenth diode in sequence, the fourth electrode is also electrically connected to the fourteenth diode, the fifteenth diode and the fourth inductor in sequence, the fifth electrode is electrically connected to the sixteenth diode, the seventeenth diode and the fifth inductor in sequence, the fifth electrode is also electrically connected to the fourth inductor, the eighteenth diode and the nineteenth diode in sequence, the sixth electrode is electrically connected to the fifth inductor, the twentieth diode and the twenty-first diode in sequence;

[0012] Furthermore, a cold environment battery pulse current balancing self-heating method based on a mutual inductance transformer is constructed by utilizing a mutual inductance balancing system to realize a heating strategy for an energy storage power source, a heating control strategy for a battery heating system based on a mutual inductance equalizer, and a coordinated strategy for balancing function and heating function. This solves the problem of difficulty and high cost in realizing a pulse current heating system for a series energy storage battery pack in a cold environment.

[0013] The diode assembly and the inductor assembly are connected in series to form a balancing unit, and the balancing unit and the electrode assembly are electrically connected to form a mutual inductance equalizer. The mutual inductance balancing system is used to implement a heating strategy for the energy storage power supply and realize internal heating of the energy storage battery.

[0014] Furthermore, the internal heating function of the battery is realized through pulse current. Since no additional heating system is used, only the mutual inductance transformer balancing system is used to achieve the balancing and heating of the power battery, thereby diluting the cost of the energy storage system.

[0015] The mutual inductance balancer also includes a battery controller; the mutual inductance balancer balances the flow of energy in the form of pulse current, and the battery controller selects two power batteries that need to be heated and charges and discharges them alternately;

[0016] Furthermore, the pulse current generates heat through the internal resistance of the battery cell, thereby realizing internal heating of the energy storage power supply. When multiple power batteries or battery packs need to be heated, the power batteries exchange and balance energy one by one, thereby realizing heating of the multiple power batteries or battery packs.

[0017] The two power batteries heat up through energy exchange, and the equalization function of the mutual inductance equalizer equalizes all the power batteries, which can end the heating process of the power batteries;

[0018] Furthermore, heating will inevitably lead to uneven energy storage among the power batteries or battery packs. Therefore, in the final stage of heating, the heating process of the power batteries or battery packs can be ended only after all the power batteries or battery packs are balanced through the equalization function of the equalizer.

[0019] The beneficial effects of the present invention are:

[0020] 1. The mutual inductance equalizer of the battery pack is used to realize pulse current heating of any two cells in a multi-cell series battery pack. The pulse current heating system can realize fast, uniform and efficient heating of lithium-ion batteries. At the same time, the equalizer is used to heat the battery, and two functions are realized through one system to dilute the cost, thereby reducing the heating cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the connection of the six-cell mutual inductance equalizer circuit of the series energy storage power supply group of the present invention;

[0022] Figure 2 It is a connection diagram of the mutual inductance equalizer of the present invention. DETAILED DESCRIPTION

[0023] The following will be combined with the attached Figure 1-2 , clearly and completely describe the technical solutions in the embodiments. Figure 1 As shown, the system has ten equalizing units, each of which is composed of two diode components and one inductor component. The ten equalizing units are electrically connected in series, and the equalizing units and the electrode components form a mutual inductance equalizer.

[0024] The cold environment battery pulse current balancing self-heating method based on mutual inductance transformer consists of three parts: a heating strategy for energy storage power source using mutual inductance balancing system, a heating control strategy for battery heating system based on mutual inductance equalizer, and a coordinated strategy for balancing function and heating function. The system is a battery balancing circuit with mutual inductance transformer as the core device; the mutual inductance equalizer realizes the energy flow between power batteries through pulse current during balancing to achieve the heating of power batteries;

[0025] like Figure 2As shown, a mutual inductance transformer is used as a relay element for energy storage to realize energy exchange of power batteries in a series battery pack; and in the process of energy exchange, the current waveforms in the discharge battery and the charge battery are pulse currents, and the internal resistance of the power battery cells releases heat under the pulse current to realize heating of the power battery. In a low temperature environment, when the power battery needs to be heated, two batteries that need to be heated are selected, and the two batteries are alternately charged and discharged through a mutual inductance equalizer. At this time, although from the perspective of balance, energy repeatedly flows between the two power batteries, when the energy flows in the form of pulse current, heat is generated in the battery cells, realizing internal heating of the battery;

[0026] The internal heating of the battery is realized by using the mutual inductance equalizer of the battery system. Since the new function of heating the battery is realized by using the existing equalization system of the battery system, no new system is introduced when heating the battery, thereby not increasing the cost of the battery system and reducing the cost of battery heating;

[0027] The battery management processor selects the two batteries or battery groups that need to be heated the most in the battery pack, and the mutual inductance equalizer first selects one battery or battery group as the discharge unit to charge the other battery or battery group, and then the other battery or battery group is used as the discharge unit to charge this battery or battery group, thereby realizing cyclic energy exchange between the two batteries or battery groups. Since the mutual inductance equalizer realizes the energy flow between the energy storage units through pulse current, the internal heating of the energy storage battery is realized;

[0028] When in use, the battery management processor selects the two batteries or battery groups that most need to be heated in the battery pack, and the mutual inductance equalizer first selects one battery or battery group as a discharge unit to charge another battery or battery group; then the other battery or battery group is used as a discharge unit to charge this battery or battery group, thereby realizing cyclic energy exchange between the two batteries or battery groups; because the mutual inductance equalizer realizes the energy flow between the energy storage units through pulse current, the internal heating of the energy storage battery is realized.

[0029] The above is only a preferred embodiment of the present invention and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this profession can make some changes or modify the technical contents disclosed above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent replacement and improvement made to the above embodiments without departing from the content of the technical solution of the present invention, based on the technical essence of the present invention, within the spirit and principles of the present invention, still fall within the protection scope of the technical solution of the present invention.

Claims

1. A cold environment battery pulse current balancing self-heating method based on a mutual inductance transformer, comprising a diode assembly, an electrode assembly and an inductor assembly, characterized in that: Also included are unidirectional transformers; The electrode assembly includes a first electrode (B1), a second electrode (B2), a third electrode (B3), a fourth electrode (B4), a fifth electrode (B5) and a sixth electrode (B6); The first electrode (B1) is electrically connected to a first diode (Q11), a second diode (Q12) and a first inductor (L12) in sequence, the second electrode (B2) is electrically connected to a first inductor (L12), a third diode (Q21) and a fourth diode (Q22) in sequence, the second electrode (B2) is also electrically connected to a fifth diode (Q23), a sixth diode (Q24) and a second inductor (L23) in sequence, the third electrode (B3) is electrically connected to a seventh diode (Q31), an eighth diode (Q32) and a third inductor (L34) in sequence, the third electrode (B3) is also electrically connected to a second inductor (L23), a tenth diode (Q33) and an eleventh diode (Q34) in sequence, the fourth electrode ( The fourth electrode (B4) is electrically connected to a third inductor (L34), a twelfth diode (Q41) and a thirteenth diode (Q42) in sequence, the fourth electrode (B4) is also electrically connected to a fourteenth diode (Q43), a fifteenth diode (Q44) and a fourth inductor (L45) in sequence, the fifth electrode (B5) is electrically connected to a sixteenth diode (Q51), a seventeenth diode (Q52) and a fifth inductor (L56) in sequence, the fifth electrode (B5) is also electrically connected to a fourth inductor (L45), an eighteenth diode (Q53) and a nineteenth diode (Q54) in sequence, and the sixth electrode (B6) is electrically connected to a fifth inductor (L56), a twentieth diode (Q61) and a twenty-first diode (Q62) in sequence.

2. The cold environment battery pulse current balancing self-heating method based on mutual inductance transformer according to claim 1 is characterized in that: The diode assembly and the inductor assembly are connected in series to form a balancing unit, and the balancing unit and the electrode assembly are electrically connected to form a mutual inductance equalizer. The mutual inductance balancing system is used to implement the heating strategy of the energy storage power supply and realize the internal heating of the energy storage battery.

3. The cold environment battery pulse current balancing self-heating method based on mutual inductance transformer according to claim 2 is characterized in that: The mutual inductance balancer also includes a battery controller; The mutual inductance balancer balances the flow of energy in the form of pulse current, and the battery controller selects the two power batteries that need to be heated and charges and discharges them alternately.

4. The cold environment battery pulse current balancing self-heating method based on mutual inductance transformer according to claim 3 is characterized in that: The two power batteries are heated by exchanging energy.

5. The cold environment battery pulse current balancing self-heating method based on mutual inductance transformer according to claim 2 is characterized in that: The equalization function of the mutual inductance equalizer can equalize all power batteries and end the heating process of the power batteries.

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