Heating circuit, battery assembly, control system and vehicle

Abstract

The invention discloses a heating circuit, a battery assembly, a control system and a vehicle, relates to the technical field of battery heating, and aims to enable a battery to be rapidly heated at a low temperature and enable the battery to be at a proper working temperature. The heating circuit comprises a switch sub-circuit, a one-way conduction sub-circuit, a first capacitor and a first inductor; the first end of the first capacitor is electrically connected with the first end of the battery, and the second end of the first capacitor is electrically connected with the second end of the battery; the first end of the switch sub-circuit is electrically connected with the first end of the first capacitor, and the second end of the switch sub-circuit is electrically connected with the first end of the first inductor; the switch sub-circuit is configured to be switched on at a set frequency, and alternating current flowing through the battery is generated in the heating circuit through the battery and the first capacitor.

Description

Technical Field

[0001] The present invention relates to the technical field of battery heating, and in particular to a heating circuit, a battery assembly, a control system and a vehicle. Background Art

[0002] With the rapid development of new energy vehicles and the widespread use of electric vehicles, the power, energy and charge and discharge performance of electric vehicle power batteries will be greatly reduced when they are at low temperatures, especially below -20℃. The attenuation of various aspects of power battery performance is particularly obvious, which has a great impact on the popularization of electric vehicles.

[0003] At present, low-temperature heating methods for power batteries can be divided into external heating and internal heating. Among them, external heating generally sets a heating device on the outside of the battery to heat the battery, but the external heating rate is slow, the heating is uneven and the efficiency is low, and the heat loss is large during the transfer process. Internal heating is generally carried out by adding additional electrical components to perform AC charging and discharging heating on electric vehicles. At present, it mainly uses the coil windings of three-phase motors to control the opening and closing of the full-bridge inverter to store and release energy in capacitors and inductors, and generate AC current at the battery end to heat the power battery. However, this heating method generates a small AC current at the battery end and has low heating efficiency. Summary of the invention

[0004] The object of the present invention is to provide a heating circuit, a battery assembly, a control system and a vehicle, which are intended to allow the battery to quickly heat up at a low temperature and keep the battery at a suitable operating temperature.

[0005] In order to achieve the above object, the present invention adopts the following technical scheme:

[0006] In a first aspect, the present invention provides a heating circuit, comprising: a switch subcircuit, a first capacitor and a first inductor; the first end of the first capacitor is used to be electrically connected to the first end of the battery, and the second end of the first capacitor is used to be electrically connected to the second end of the battery; the first end of the switch subcircuit is electrically connected to the first end of the first capacitor, and the second end of the switch subcircuit is electrically connected to the first end of the first inductor; the first end of the unidirectional conducting subcircuit is electrically connected to the first end of the first inductor, the second end of the unidirectional conducting subcircuit is electrically connected to the second end of the first inductor, the third end of the unidirectional conducting subcircuit is electrically connected to the first end of the first capacitor, and the fourth end of the unidirectional conducting subcircuit is electrically connected to the second end of the first capacitor; the switch subcircuit is configured to be turned on at a set frequency, so that an alternating current flows through the battery in the heating circuit through the battery, the first inductor, the unidirectional conducting subcircuit, and the first capacitor, so that the battery generates heat.

[0007] Based on the above scheme, some embodiments of the present application provide a heating circuit, which is opened and closed at a set frequency through a switch subcircuit, and cooperates with a first capacitor and a first inductor to generate series resonance, thereby generating an alternating current at both ends of the battery. The series resonance reduces the impedance of the heating circuit and maximizes the alternating current, and the heating efficiency is highest at this time; the alternating current flows through the battery, causing the internal resistance of the battery to generate heat, thereby quickly heating the battery from the inside.

[0008] In some embodiments, the unidirectional conducting sub-circuit includes: a first diode, the positive electrode of the first diode is electrically connected to the second end of the unidirectional conducting sub-circuit, and the negative electrode of the first diode is electrically connected to the fourth end of the unidirectional conducting sub-circuit; when the switch sub-circuit is turned on, the battery, the switch sub-circuit, the first inductor and the first diode form a first loop; the current direction inside the battery is from the second end of the battery to the first end of the battery.

[0009] In some embodiments, the unidirectional conducting sub-circuit further includes: a second diode and a third diode, the anode of the second diode being electrically connected to the fourth end of the unidirectional conducting sub-circuit, and the cathode of the second diode being electrically connected to the first end of the unidirectional conducting sub-circuit; the anode of the third diode being electrically connected to the second end of the unidirectional conducting sub-circuit, and the cathode of the third diode being electrically connected to the third end of the unidirectional conducting sub-circuit.

[0010] When the switch subcircuit is disconnected, the first inductor, the third diode, the battery and the second diode form a second loop; the current in the battery flows from the first end of the battery to the second end of the battery.

[0011] In some embodiments, the heating circuit further includes: a first resistor, a second resistor and a third resistor. The first resistor is connected in parallel with the first diode, the second resistor is connected in parallel with the second diode, and the third resistor is connected in parallel with the third diode.

[0012] In some embodiments, the switch subcircuit includes: a first transistor, the control end of the first transistor is used to receive a control signal, the control signal is used to control the first transistor to be turned on or off; the first end of the first transistor is the first end of the switch subcircuit; the second end of the first transistor is the second end of the switch subcircuit.

[0013] In some embodiments, the switch subcircuit further includes: a fourth diode, wherein an anode of the fourth diode is electrically connected to the second end of the first transistor, and a cathode of the fourth diode is electrically connected to the first end of the first transistor.

[0014] In some embodiments, the set frequency is negatively correlated to the product of the capacitance of the first capacitor and the inductance of the first inductor.

[0015] In some embodiments, the heating circuit also includes: a first interface and a second interface, the heating device is connected between the first interface and the second interface; the first interface is electrically connected to the positive electrode of the second diode, and the second interface is electrically connected to the negative electrode of the first diode; when the switch subcircuit is disconnected, the first inductor, the first diode, the heating device and the second diode form a third loop to enable the heating device to generate heat.

[0016] In a second aspect, the present application provides a battery assembly, comprising: a battery and the above-mentioned heating circuit.

[0017] Among them, the beneficial effects of the second aspect and its possible embodiments can refer to the first aspect and will not be repeated here.

[0018] In some embodiments, the battery assembly further includes: a heating device; when the heating circuit further includes a first interface and a second interface, and the heating device is connected between the first interface and the second interface; the heating device is electrically connected to the second end of the battery through the second interface.

[0019] In some embodiments, the battery includes a first surface and a second surface that are arranged opposite to each other in a thickness direction of the battery; and the heating device is arranged on the first surface and / or the second surface of the battery.

[0020] In some embodiments, the battery assembly further includes: a heat-conducting structure disposed between the heating device and the battery and in contact with the heating device and the battery.

[0021] In a third aspect, the present application provides a control system, comprising: the above-mentioned battery assembly and a controller; the controller is electrically connected to the control end of the switch subcircuit of the heating circuit in the battery assembly; the controller is used to output a control signal to the switch subcircuit to turn on or off the switch subcircuit according to the set frequency.

[0022] Among them, the beneficial effects of the third aspect and its possible embodiments can refer to the first aspect and will not be repeated here.

[0023] In some embodiments, the control signal is a pulse width modulation signal, and the period of the pulse width modulation signal is the inverse of the set frequency.

[0024] In some embodiments, the controller is further used to obtain the temperature of the battery in the battery assembly and adjust the duty cycle of the pulse width modulation signal according to the temperature of the battery.

[0025] In a fourth aspect, the present application provides a vehicle, comprising: a vehicle body and the above-mentioned control system.

[0026] Among them, the beneficial effects of the fourth aspect and its possible embodiments can refer to the first aspect and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0028] Figure 1 A schematic diagram of an existing self-heating battery circuit provided in an embodiment of the present application;

[0029] Figure 2 A schematic diagram of a heating circuit provided in an embodiment of the present application;

[0030] Figure 3 A schematic diagram of a first loop of a heating circuit provided in an embodiment of the present application;

[0031] Figure 4 A schematic diagram of a second loop of a heating circuit provided in an embodiment of the present application;

[0032] Figure 5 A schematic diagram of a switch subcircuit provided in an embodiment of the present application;

[0033] Figure 6 A schematic diagram of a third loop of a heating circuit provided in an embodiment of the present application;

[0034] Figure 7 A schematic diagram of a battery assembly provided in an embodiment of the present application;

[0035] Figure 8 A schematic diagram of a control system provided in an embodiment of the present application;

[0036] Fig. 9 A schematic diagram of simulation of internal current and external current provided in an embodiment of the present application;

[0037] Fig.10 A schematic diagram of formula derivation provided in an embodiment of the present application;

[0038] Fig.11 A schematic diagram of a means of transportation provided in an embodiment of the present application.

[0039] Figure numerals: 1, switch subcircuit; 2, unidirectional conduction subcircuit; 3, heating device; 4, heat-conducting structure; 100, heating circuit; 110, battery; 200, battery assembly; 210, controller; 300, control system; 400, vehicle; 410, vehicle body; C1, first capacitor; L1, first inductor; D1, first diode; D2, second diode; D3, third diode; D4, fourth diode; R1, first resistor; R2, second resistor; R3, third resistor; S1, first transistor; X1, first interface; X2, second interface; A, first surface; B, second surface. DETAILED DESCRIPTION

[0040] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only 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 creative work are within the scope of protection of the present invention.

[0041] In the description of the invention, it should be understood that the terms "upper", "lower", "left", "right", "front", "back", "inside", "outside" and the like indicate directions or positional relationships based on the directions or relative positional relationships shown in the drawings, and are only for the convenience of describing the invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the invention. Unless otherwise specified, the above-mentioned directional description can be flexibly set in the process of actual application under the condition that the relative positional relationship shown in the drawings is satisfied.

[0042] The terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0043] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection. It can be directly connected, or indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0044] In the embodiments of the present invention, the terms "comprises", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, article or device including a series of elements includes not only those elements, but also includes other elements not explicitly listed, or also includes elements inherent to such process, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, article or device including the element.

[0045] In the embodiments of the present invention, words such as "exemplary" or "for example" are used to indicate examples, illustrations or explanations. Any embodiment or design described as "exemplary" or "for example" in the embodiments of the present invention should not be interpreted as being more preferred or more advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary" or "for example" is intended to present related concepts in a specific way.

[0046] With the rapid development of new energy vehicles and the widespread use of electric vehicles, the power, energy and charge and discharge performance of electric vehicle power batteries will be greatly reduced when they are at low temperatures, especially below -20℃. The attenuation of various aspects of power battery performance is particularly obvious, which has a great impact on the popularization of electric vehicles.

[0047] At present, low-temperature heating methods for power batteries can be divided into external heating and internal heating. Among them, external heating generally sets a heating device on the outside of the battery to heat the battery, but the external heating rate is slow, the heating is uneven and the efficiency is low, and the heat loss is large during the transfer process. Internal heating is generally carried out by adding additional electrical components to perform AC charging and discharging heating on electric vehicles. At present, it mainly uses the coil windings of three-phase motors to control the opening and closing of the full-bridge inverter to store and release energy in capacitors and inductors, and generate AC current at the battery end to heat the power battery. However, this heating method generates a small AC current at the battery end and has low heating efficiency.

[0048] For example, refer to Figure 1 , Figure 1 The invention discloses an existing self-heating battery circuit, comprising: a high-voltage battery having a terminal, a parasitic internal resistance R11 and a parasitic terminal inductance L11; wherein the parasitic terminal inductance L11, a current storage device L12 and a charge storage device C11 together constitute a resonant circuit to generate a high alternating current with a resonant frequency.

[0049] An energy superposition unit is connected across the charge storage device C11 of the resonant circuit and includes a switch (K1), wherein K1 is turned on and off at the resonant frequency according to a switch control signal, thereby generating a high alternating current through the high-voltage battery. However, this method requires obtaining the internal inductance of the high-voltage battery, that is, the parasitic terminal inductance L11, and the method of obtaining the inductance is relatively complicated. In addition, this method only heats the high-voltage battery internally, so that there is a temperature difference between the two ends and the middle part of the high-voltage battery, which is not conducive to the normal operation of the battery.

[0050] Based on this, an embodiment of the present application provides a heating circuit. For example, Figure 2 As shown, the heating circuit 100 includes: a switch sub-circuit 1, a unidirectional conduction sub-circuit 2, a first capacitor C1 and a first inductor L1.

[0051] The switch sub-circuit 1 includes a first terminal 101 and a second terminal 102 .

[0052] The unidirectional conducting sub-circuit 2 includes: a first terminal 201 , a second terminal 202 , a third terminal 203 and a fourth terminal 204 .

[0053] The first end of the first capacitor C1 is used to be electrically connected to the first end 111 of the battery 110 , and the second end of the first capacitor C1 is used to be electrically connected to the second end 112 of the battery 110 .

[0054] The first end 101 of the switch sub-circuit 1 is electrically connected to the first end of the first capacitor C1 , and the second end 102 of the switch sub-circuit 1 is electrically connected to the first end of the first inductor L1 .

[0055] The first end 201 of the unidirectional conducting sub-circuit 2 is electrically connected to the first end of the first inductor L1, the second end 202 of the unidirectional conducting sub-circuit 2 is electrically connected to the second end of the first inductor L1, the third end 203 of the unidirectional conducting sub-circuit 2 is electrically connected to the first end of the first capacitor C1, and the fourth end 204 of the unidirectional conducting sub-circuit 2 is electrically connected to the second end of the first capacitor C1.

[0056] The switch subcircuit 1 is configured to be turned on at a set frequency f, so as to generate an alternating current flowing through the battery in the heating circuit through the battery 110 , the first capacitor C1 , the first inductor L1 and the unidirectional conduction subcircuit 2 , and the battery 110 generates heat.

[0057] The first capacitor C1 has the function of storing energy, and will be pre-charged before the heating circuit works, so that the voltage across the battery 110 will be the same as the voltage across the first capacitor C1. The first inductor L1 also has the function of storing energy.

[0058] When the switch subcircuit 1 is turned on at the set frequency f, the battery 110 supplies power to the heating circuit 100 and also charges the first inductor L1. When the switch subcircuit 1 is turned on at the set frequency, the first inductor discharges to provide power to the heating circuit.

[0059] The set frequency f is related to the capacitance Cx of the first capacitor C1 and the inductance Lx of the first inductor L1. The set frequency f is negatively correlated to the product of the capacitance Cx of the first capacitor C1 and the inductance Lx of the first inductor L1.

[0060] When the switch sub-circuit is turned on and off at a set frequency, the first capacitor C1 and the first inductor L1 form a series resonance, thereby generating an alternating current at both ends of the battery.

[0061] Series resonance refers to the phenomenon that the power supply, voltage, and current are in phase in a series circuit of resistors, capacitors, and inductors. The circuit is purely resistive, the reactance X is equal to 0, and the impedance Z is equal to the resistance R.

[0062] The resistance refers to the internal resistance r (not shown in the figure) of the battery 110 , the capacitance refers to the first capacitor C1 mentioned above, and the inductance refers to the first inductor L1 mentioned above.

[0063] The total impedance of the circuit is:

[0064]

[0065] Where ω is the angular frequency, set the frequency f = ω / 2π, When At this time, the impedance of the first capacitor and the impedance of the first inductor are offset, and the total impedance of the circuit is r.

[0066] Compared with the previous impedance, when the frequency is set to The impedance is smallest, and the voltage across the battery is U. When the battery voltage remains unchanged, the alternating current is maximum, so the heating efficiency is highest; the alternating current flows through the battery, causing the internal resistance of the battery to generate heat, thereby heating the battery from the inside.

[0067] Among them, the power consumed by the alternating current flowing through the internal resistance of the battery is the heating power of the battery.

[0068] For example, when the outside temperature is low, the battery needs to be heated. The inside of the battery can be heated quickly, allowing the battery to function normally.

[0069] Compared with the prior art, the present application does not need to accurately obtain the internal inductance parameters of the power battery, and the process of obtaining the internal inductance parameters of the power battery is relatively complicated. The solution of the present application is simpler.

[0070] In summary, some embodiments of the present application provide a heating circuit, which is opened and closed at a set frequency through a switch subcircuit, and cooperates with a first capacitor and a first inductor to generate series resonance, thereby generating an alternating current at both ends of the battery. The series resonance reduces the impedance of the heating circuit and maximizes the alternating current, at which time the heating efficiency is the highest; the alternating current flows through the battery, causing the internal resistance of the battery to generate heat, thereby quickly heating the battery from the inside.

[0071] like Figure 3 As shown, in some embodiments, the unidirectional conducting sub-circuit 2 includes: a first diode D1.

[0072] The second terminal 102 of the switch sub-circuit 1 is electrically connected to the first terminal of the first inductor L1 .

[0073] An anode of the first diode D1 is electrically connected to the second end 202 of the unidirectional conducting sub-circuit 2 , and a cathode of the first diode D1 is electrically connected to the fourth end 204 of the unidirectional conducting sub-circuit 2 .

[0074] That is, the anode of the first diode D1 is electrically connected to the second end of the first inductor L1 , and the cathode of the first diode D1 is electrically connected to the second end of the first capacitor C1 .

[0075] When the switch subcircuit 1 is turned on, the battery 110 , the switch subcircuit 1 , the first inductor L1 and the first diode D1 form a first loop; the current direction inside the battery 110 flows from the second end of the battery 110 to the first end of the battery 110 .

[0076] That is to say, when the switch sub-circuit 1 is turned on, the current flows from the first end 111 of the battery 110 to the first end 101 of the switch sub-circuit 1, and then flows from the second end 102 of the switch sub-circuit 1 to the first inductor L1. After the first inductor L1 is fully charged, the current flows from the second end of the first inductor L1 to the second end 112 of the battery 110, forming a first loop.

[0077] in, Figure 3 The direction of the arrow in the middle is the direction of the current in the first circuit. When the battery is continuously discharged, the first capacitor C1 will also charge the battery in time.

[0078] like Figure 4 As shown, in some embodiments, the unidirectional conducting sub-circuit 2 further includes: a second diode D2 and a third diode D3.

[0079] The anode of the second diode D2 is electrically connected to the fourth end 204 of the unidirectional conducting sub-circuit 2 , and the cathode of the second diode D2 is electrically connected to the first end 201 of the unidirectional conducting sub-circuit 2 .

[0080] An anode of the third diode D3 is electrically connected to the second end 202 of the unidirectional conducting sub-circuit 2 , and a cathode of the third diode D3 is electrically connected to the third end 203 of the unidirectional conducting sub-circuit 2 .

[0081] That is, the anode of the second diode D2 is electrically connected to the second end of the first capacitor C1, and the cathode of the second diode D2 is electrically connected to the first end of the first inductor L1; the anode of the third diode D3 is electrically connected to the second end of the first inductor L1, and the cathode of the third diode D3 is electrically connected to the first end of the first capacitor C1.

[0082] When the switch subcircuit 1 is disconnected, the first inductor L1 , the third diode D3 , the battery 110 and the second diode D2 form a second loop; the current direction inside the battery 110 flows from the first end of the battery 110 to the second end of the battery 110 .

[0083] That is to say, when the switch sub-circuit 1 is disconnected, the current flows from the second end of the first inductor L1 to the anode of the third diode D3, then flows from the cathode of the third diode to the first end of the battery 110, then flows from the second end 112 of the battery 110 to the anode of the second diode D2, and finally flows to the first end of the first inductor L1 through the cathode of the second diode, forming a second loop.

[0084] in, Figure 4 The direction of the arrow is the direction of the current in the second loop. When the first inductor is continuously discharged, the second loop is formed.

[0085] Reference Figure 3 and Figure 4 It can be seen that when the switch subcircuit 1 is turned on, a first loop is formed; when the switch subcircuit 1 is turned off, a second loop is formed; the currents in the two loops are opposite, so an alternating current is formed at both ends of the battery.

[0086] The heating circuit 100 is switched on and off at a set frequency through the switch subcircuit 1, and cooperates with the first capacitor C1 and the first inductor L1 to generate series resonance, thereby generating an alternating current at both ends of the battery. The series resonance reduces the impedance of the heating circuit 100 and maximizes the alternating current, at which time the heating efficiency is the highest; the alternating current flows through the battery, causing the internal resistance of the battery to generate heat, thereby quickly heating the battery from the inside.

[0087] like Figure 3 and 4 As shown, in some embodiments, the heating circuit 100 further includes: a first resistor R1, a second resistor R2 and a third resistor R3.

[0088] The first resistor R1 is connected in parallel with the first diode D1 , the second resistor R2 is connected in parallel with the second diode D2 , and the third resistor R3 is connected in parallel with the third diode D3 .

[0089] Resistors and diodes are connected in parallel in a circuit to protect the circuit from damage caused by excessive voltage or excessive current. When the voltage or current exceeds the normal range, the excess voltage or current will be diverted to the diode, thereby protecting other components from damage. At the same time, resistors and diodes connected in parallel can also stabilize the working state of the circuit.

[0090] like Figure 5 As shown, in some embodiments, the switch subcircuit 1 includes: a first transistor S1.

[0091] The control terminal of the first transistor S1 is used to receive a control signal, and the control signal is used to control the first transistor S1 to be turned on or off.

[0092] The first end of the first transistor S1 is the first end of the switch sub-circuit 1 ; the second end of the first transistor S1 is the second end of the switch sub-circuit 1 .

[0093] For example, if the first transistor S1 is an NPN transistor, when the control signal received by the first transistor S1 is at a high level, the first transistor S1 is turned on, that is, the switch subcircuit is turned on; when the control signal received by the first transistor S1 is at a low level, the first transistor S1 is turned off, that is, the switch subcircuit is turned off.

[0094] That is to say, when the control signal received by the first transistor S1 is at a high level, the first transistor S1 is turned on, and at this time, the current flows from the first end 111 of the battery 110 to the first end 101 of the switch subcircuit 1, and then flows from the second end 102 of the switch subcircuit 1 to the first inductor L1. After the first inductor L1 is fully charged, the current flows from the second end of the first inductor L1 to the second end 112 of the battery 110, forming a first loop.

[0095] When the control signal received by the first transistor S1 is at a low level, the first transistor S1 is disconnected, and the current flows from the second end of the first inductor L1 to the positive electrode of the third diode D3, then flows from the negative electrode of the third diode to the first end of the battery 110, then flows from the second end 112 of the battery 110 to the positive electrode of the second diode D2, and finally flows to the first end of the first inductor L1 through the negative electrode of the second diode, forming a second loop.

[0096] The currents in the first loop and the second loop are opposite, so an alternating current is formed at both ends of the battery 110. The heating circuit 100 is switched on and off at a set frequency through the switch subcircuit 1, and cooperates with the first capacitor C1 and the first inductor L1 to generate series resonance. The series resonance makes the impedance of the heating circuit 100 smaller, the alternating current is the largest, and the heating efficiency is the highest at this time; the alternating current flows through the battery, causing the internal resistance of the battery to generate heat, thereby quickly heating the battery from the inside.

[0097] When the outside temperature is low, the battery needs to be heated. At this time, the high and low level conversion frequency of the control signal can be adjusted, that is, the frequency is set to The inside of the battery can be heated quickly, allowing the battery to function normally.

[0098] In some embodiments, the switch sub-circuit 1 further includes: a fourth diode D4.

[0099] An anode of the fourth diode D4 is electrically connected to the second end of the first transistor S1 , and a cathode of the fourth diode D4 is electrically connected to the first end of the first transistor S1 .

[0100] The fourth diode D4 plays the role of voltage stabilization and input impedance adaptation. When the input signal changes, the fourth diode D4 can automatically adjust its conduction state to maintain the stability of the output voltage.

[0101] like Figure 6 As shown, in some embodiments, the heating circuit 100 further includes: a first interface X1 and a second interface X2, for connecting a heating device 3 that generates heat when current flows. That is, the heating device 3 is connected between the first interface X1 and the second interface X2.

[0102] The first interface X1 is electrically connected to the positive electrode of the second diode D2, and the second interface X2 is electrically connected to the negative electrode of the first diode D1; when the switch subcircuit 1 is disconnected, the first inductor L1, the first diode D1, the heating device 3 and the second diode D2 form a third loop to enable the heating device 3 to generate heat.

[0103] That is to say, when the switch subcircuit 1 is disconnected, the current flows from the second end of the first inductor L1 to the anode of the first diode D1, then from the cathode of the first diode D1 to the second interface X2, then flows through the heating device 3, then flows from the first interface X1 to the anode of the second diode D2, and finally flows from the cathode of the second diode D2 to the first end of the first inductor L1, forming a third loop.

[0104] in, Figure 6 The direction of the arrow is the direction of the current in the third loop. When the first inductor is continuously discharged, the third loop is formed.

[0105] When the switch subcircuit 1 is turned off, the first inductor L1 supplies power to the heating device 3 , thereby performing external heating on the battery 110 .

[0106] In a second aspect, the present application provides a battery assembly 200, referring to Figure 6 The battery assembly 200 includes: a battery 110 and the above-mentioned heating circuit 100.

[0107] The battery assembly 200 further includes a heating device 3 .

[0108] The heating circuit 100 further includes a first interface X1 and a second interface X2 , and the heating device 3 is connected between the first interface X1 and the second interface X2 ; the heating device 3 is connected to the battery 110 .

[0109] like Figure 7 As shown, in some embodiments, the battery 110 includes a first surface A and a second surface B that are arranged opposite to each other in the thickness direction of the battery 110 ; the heating device 3 is arranged on the first surface A and / or the second surface B of the battery 110 .

[0110] That is to say, the heating device 3 can be arranged only on the first surface A, or only on the second surface B, or on both the first surface A and the second surface B.

[0111] When the heating device 3 is only arranged on the first surface A, the switch subcircuit 1 is firstly placed in an off state, and the current flows from the second end of the first inductor L1 to the anode of the first diode D1, and then from the cathode of the first diode D1 to the second interface X2, and then flows through the heating device 3, and then flows from the first interface to the anode of the second diode D2, and finally flows from the cathode of the second diode to the first end of the first inductor L1, forming a third loop; the first inductor L1 supplies power to the heating device 3, and the heating device 3 generates heat, thereby externally heating the first surface A of the battery 110.

[0112] When the heating device 3 is only arranged on the second surface B, the switch subcircuit 1 is firstly placed in an off state, and the current flows from the second end of the first inductor L1 to the anode of the first diode D1, and then from the cathode of the first diode D1 to the second interface X2, and then flows through the heating device 3, and then flows from the first interface to the anode of the second diode D2, and finally flows from the cathode of the second diode to the first end of the first inductor L1, forming a third loop; the first inductor L1 supplies power to the heating device 3, and the heating device 3 generates heat, thereby externally heating the second surface B of the battery 110.

[0113] When the heating device 3 is arranged on the first surface A and the second surface B, the switch subcircuit 1 is firstly placed in an off state, and the current flows from the second end of the first inductor L1 to the anode of the first diode D1, and then from the cathode of the first diode D1 to the second interface X2, and then flows through the heating device 3, and then flows from the first interface to the anode of the second diode D2, and finally flows from the cathode of the second diode to the first end of the first inductor L1, forming a third loop; the first inductor L1 supplies power to the heating device 3, and the heating device 3 generates heat, thereby externally heating the first surface A and the second surface B of the battery 110.

[0114] Among them, the above three methods can all heat the battery, and the heating locations and efficiencies of the three methods are different.

[0115] like Figure 7 As shown, in some embodiments, the battery assembly 200 further includes: a heat-conducting structure 4 , which is disposed between the heating device 3 and the battery 110 , and is in contact with the heating device 3 and the battery 110 .

[0116] When the heating device 3 is only arranged on the first surface A, the switch subcircuit 1 is firstly placed in an off state, and the current flows from the second end of the first inductor L1 to the positive electrode of the first diode D1, and then from the negative electrode of the first diode D1 to the second interface X2, and then flows through the heating device, and then flows from the first interface to the positive electrode of the second diode D2, and finally flows from the negative electrode of the second diode to the first end of the first inductor L1, forming a third loop; the first inductor L1 supplies power to the heating device 3, the heating device 3 generates heat, and transmits the heat to the first surface A of the battery 110 through the heat-conducting structure 4, so that the heating efficiency is higher, thereby externally heating the first surface A of the battery 110.

[0117] When the heating device 3 is only arranged on the second surface B, the switch subcircuit 1 is firstly placed in an off state, and the current flows from the second end of the first inductor L1 to the positive electrode of the first diode D1, and then from the negative electrode of the first diode D1 to the second interface X2, and then flows through the heating device, and then flows from the first interface to the positive electrode of the second diode D2, and finally flows from the negative electrode of the second diode to the first end of the first inductor L1, forming a third loop; the first inductor L1 supplies power to the heating device 3, the heating device 3 generates heat, and transmits the heat to the second surface B of the battery 110 through the heat-conducting structure 4, so that the heating efficiency is higher, thereby externally heating the second surface B of the battery 110.

[0118] When the heating device 3 is arranged on the first surface A and the second surface B, the switch subcircuit 1 is firstly placed in an off state, and the current flows from the second end of the first inductor L1 to the positive electrode of the first diode D1, and then from the negative electrode of the first diode D1 to the second interface X2, and then flows through the heating device, and then flows from the first interface to the positive electrode of the second diode D2, and finally flows from the negative electrode of the second diode to the first end of the first inductor L1, forming a third loop; the first inductor L1 supplies power to the heating device 3, the heating device 3 generates heat, and the heat is transferred to the first surface A and the second surface B of the battery 110 through the heat-conducting structure 4, so that the heating efficiency is higher, thereby externally heating the first surface A and the second surface B of the battery 110.

[0119] In this way, the battery assembly 200 heats the inside and outside of the battery through the heating circuit; the switch subcircuit is disconnected at a set frequency, and the first capacitor and the first inductor are used to generate series resonance, thereby generating an alternating current at both ends of the battery. The series resonance reduces the impedance of the heating circuit, and the alternating current is maximum, and the heating efficiency is highest at this time; the alternating current flows through the battery, causing the internal resistance of the battery to generate heat, thereby quickly heating the battery from the inside. At the same time, when the switch subcircuit is disconnected, the heating device is heated by the discharge of the first inductor, and the heat is transferred through the heat-conducting structure 4 to improve the heating efficiency. As a result, the inside and outside of the battery are heated evenly, and can work better.

[0120] In a third aspect, the present application provides a control system 300, such as Figure 8 As shown, it includes: a control system 300 including the battery assembly 200 and a controller 210 mentioned above.

[0121] The controller 210 is electrically connected to the control end of the switch subcircuit 1 of the heating circuit 100 in the battery assembly 200; the controller is used to output a control signal to the switch subcircuit 1 to turn on or off the switch subcircuit 1 according to the set frequency.

[0122] That is, the controller 210 is electrically connected to the control terminal of the first transistor S1.

[0123] In some embodiments, the control signal is a pulse width modulation signal, and the period of the pulse width modulation signal is the inverse of the set frequency.

[0124] For example, when the battery voltage U is 550V, the battery internal resistance r is 0.1Ω, the capacitance value of the first capacitor C1 is 40μF, the inductance value of the first inductor L1 is 80μH, and the resistance value of the heating device 3 is 0.5Ω, the controller controls the first transistor S1 by setting the frequency f and the pulse width modulation signal with a duty cycle of 50%, so that the waveforms of the current at both ends of the battery and the current on the heating device 3 are as follows: Fig. 9 As shown, Fig. 9 This is a simulation diagram of internal current and external current. Fig. 9 The solid line in the middle is the current at the power battery terminal, that is, the internal current; the dotted line is the current on the heating device 3, that is, the external current.

[0125] For specific formulas, please refer to Fig.10 :

[0126]

[0127] Among them, i2=L1×C1×i3, i1=i2+i3; x1 is the real part of the conjugate complex number, and x2 is the imaginary part of the conjugate complex number.

[0128] From the initial conditions t=0, i1=0, i2=0, i3=0, the coefficients c1 and c2 can be calculated.

[0129] Use the moment of the switch action to determine the initial value of the next state, and find different c1 and c2 and keep iterating.

[0130] In some embodiments, the controller is further used to obtain the temperature of the battery 110 in the battery assembly 200 and adjust the duty cycle of the pulse width modulation signal according to the temperature of the battery 110 .

[0131] For example, when the battery temperature is lower than the set value, the controller controls the switch subcircuit 1 to switch at the set frequency f and a duty cycle of 5%, and the battery starts to heat. The duty cycle is controlled according to the actual effect of battery heating. If the battery heating rate needs to be increased, the duty cycle is increased, otherwise, the duty cycle is reduced.

[0132] When the temperature of the battery rises to a desired temperature, the controller controls the switch subcircuit 1 to be disconnected to stop heating the battery.

[0133] In a fourth aspect, the present application provides a means of transportation, such as Fig.11 As shown, the vehicle 400 includes: a vehicle body 410 and the above-mentioned control system 300.

[0134] For example, the user can control the control system to heat the battery by pressing a button, and the vehicle itself can also set the optimal duty cycle to heat the battery by detecting the external temperature.

[0135] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0136] The above are only specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A heating circuit, characterized in that: include: A switch subcircuit (1), a unidirectional conduction subcircuit (2), a first capacitor (C1) and a first inductor (L1); The first end of the first capacitor (C1) is used to be electrically connected to the first end of the battery (110), and the second end of the first capacitor (C1) is used to be electrically connected to the second end of the battery (110); the first end of the switch subcircuit (1) is electrically connected to the first end of the first capacitor (C1), and the second end of the switch subcircuit (1) is electrically connected to the first end of the first inductor (L1); The first end of the unidirectional conducting subcircuit (2) is electrically connected to the first end of the first inductor (L1), the second end of the unidirectional conducting subcircuit (2) is electrically connected to the second end of the first inductor (L1), the third end of the unidirectional conducting subcircuit (2) is electrically connected to the first end of the first capacitor (C1), and the fourth end of the unidirectional conducting subcircuit (2) is electrically connected to the second end of the first capacitor (C1); The switch subcircuit (1) is configured to be turned on at a set frequency, and to generate an alternating current flowing through the battery (110) in the heating circuit (100) via the battery (110), the first capacitor (C1), the first inductor (L1) and the unidirectional conduction subcircuit (2).

2. The heating circuit (100) according to claim 1, characterized in that: The unidirectional conducting subcircuit (2) comprises: a first diode (D1), wherein an anode of the first diode (D1) is electrically connected to a second end of the unidirectional conducting sub-circuit (2), and a cathode of the first diode (D1) is electrically connected to a fourth end of the unidirectional conducting sub-circuit (2); When the switch subcircuit (1) is turned on, the battery (110), the switch subcircuit (1), the first inductor (L1) and the first diode (D1) form a first loop, so that the current inside the battery (110) flows from the second end of the battery (110) to the first end of the battery (110).

3. The heating circuit (100) according to claim 2, characterized in that: The unidirectional conducting subcircuit (2) further comprises: a second diode (D2), wherein an anode of the second diode (D2) is electrically connected to a fourth end of the unidirectional conducting sub-circuit (2), and a cathode of the second diode (D2) is electrically connected to a first end of the unidirectional conducting sub-circuit (2); a third diode (D3), wherein an anode of the third diode (D3) is electrically connected to the second end of the unidirectional conducting sub-circuit (2), and a cathode of the third diode (D3) is electrically connected to the third end of the unidirectional conducting sub-circuit (2); When the switch subcircuit (1) is disconnected, the first inductor (L1), the third diode (D3), the battery (110) and the second diode (D2) form a second loop so that the current inside the battery (110) flows from the first end of the battery (110) to the second end of the battery (110).

4. The heating circuit (100) according to claim 3, characterized in that: The heating circuit (100) further comprises: a first resistor (R1), a second resistor (R2) and a third resistor (R3); The first resistor (R1) is connected in parallel with the first diode (D1), the second resistor (R2) is connected in parallel with the second diode (D2), and the third resistor R3 is connected in parallel with the third diode (D3).

5. The heating circuit (100) according to any one of claims 1 to 4, characterized in that: The switch subcircuit (1) comprises: A first transistor (S1), wherein a control end of the first transistor (S1) is used to receive a control signal, wherein the control signal is used to control the first transistor (S1) to be turned on or off; the first end of the first transistor (S1) is the first end of the switch subcircuit (1); and the second end of the first transistor (S1) is the second end of the switch subcircuit (1).

6. The heating circuit (100) according to claim 5, characterized in that: The switch subcircuit (1) further comprises: a fourth diode (D4); An anode of the fourth diode (D4) is electrically connected to the second end of the first transistor (S1), and a cathode of the fourth diode (D4) is electrically connected to the first end of the first transistor (S1).

7. The heating circuit (100) according to any one of claims 1 to 4, characterized in that: The set frequency is negatively correlated to the product of the capacitance value of the first capacitor (C1) and the inductance value of the first inductor (L1).

8. The heating circuit (100) according to claim 3, characterized in that: The heating circuit (100) further comprises: a first interface (X1) and a second interface (X2); A heating device (3) is connected between the first interface (X1) and the second interface (X2); The first interface (X1) is electrically connected to the positive electrode of the second diode (D2), and the second interface (X2) is electrically connected to the negative electrode of the first diode (D1); When the switch subcircuit (1) is disconnected, the first inductor (L1), the first diode (D1), the heating device (3) and the second diode (D2) form a third loop to enable the heating device (3) to generate heat.

9. A battery assembly (200), characterized in that: include: A battery (110) and a heating circuit (100) according to any one of claims 1 to 8.

10. The battery assembly (200) according to claim 9, characterized in that: The battery assembly further comprises: a heating device (3); when the heating circuit (100) further comprises a first interface (X1) and a second interface (X2), and the heating device (3) is connected between the first interface (X1) and the second interface (X2); The heating device (3) is electrically connected to the second end of the battery (110) via a second interface (X2).

11. The battery assembly (200) according to claim 9, characterized in that: The battery (110) comprises a first surface (A) and a second surface (B) which are arranged opposite to each other in the thickness direction of the battery (110); The heating device (3) is arranged on the first surface (A) and / or the second surface (B) of the battery (110).

12. The battery assembly (200) according to claim 10 or 11, characterized in that: The battery assembly (200) further comprises: a heat-conducting structure (4) disposed between the heating device (3) and the battery (110), and in contact with the heating device (3) and the battery (110).

13. A control system (300), characterized in that: include: The battery assembly (200) according to any one of claims 9 to 12; The controller (210) is electrically connected to the control end of the switch subcircuit (1) of the heating circuit (100) in the battery assembly (200); the controller (210) is used to output a control signal to the switch subcircuit (1) so that the switch subcircuit (1) is turned on according to a set frequency.

14. The control system (300) according to claim 13, characterized in that: The control signal is a pulse width modulation signal, and the period of the pulse width modulation signal is the inverse of the set frequency.

15. The control system (300) according to claim 13, characterized in that: The controller (210) is further used to obtain the temperature of the battery (110) in the battery assembly (200), and to adjust the duty cycle of the pulse width modulation signal according to the temperature of the battery (110).

16. A means of transport (400), characterized in that: include: A vehicle body (410) and a control system (300) according to any one of claims 13 to 15.

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