A battery self-heating circuit with extremely low loss

Abstract

The present invention provides a battery self-heating circuit with extremely low loss, which is connected to a battery to heat the battery. It includes a temperature detection circuit a, a current detection circuit b, a state flip circuit c, a full-bridge topology circuit, two half-bridge drivers, and a storage inductor; the loss generated by the discharge current on the self-heating circuit is extremely low, and most of the energy is generated in the battery cell in the form of heat, with high heating efficiency. The self-heating and temperature rise are realized by using the heat generated by the charge and discharge current on the internal resistance of the battery cell until the battery cell temperature rises to a certain temperature. By using a storage inductor to replace the resistor in the prior art, the loss generated by the charge and discharge current on the external circuit is extremely low, and most of the energy is generated in the battery cell in the form of heat, eliminating unnecessary energy loss and having high heating efficiency, and it can be widely applied to various batteries that require self-heating.

Description

Technical Field

[0001] The present invention belongs to the technical field of batteries, and particularly relates to a battery self-heating circuit with extremely low loss. Background Art

[0002] With the rapid development of science and industrial technology, batteries have been widely used in various fields such as communication, automobiles, and daily life.

[0003] The performance of batteries is greatly affected by environmental factors. For example, lithium-ion batteries, especially lithium iron phosphate batteries, have a significant attenuation in charge and discharge capacity at low ambient temperatures.

[0004] To improve the performance of batteries at low temperatures, the common practice is to heat up the batteries.

[0005] To heat up the batteries, one method is to heat up the entire battery pack, and the other method is to heat up each battery cell separately.

[0006] The common practice for separately heating up the battery pack or battery cells is to externally connect a discharge resistor and a discharge switch. When heating is required, the switch is closed to form a discharge circuit, and the discharge current flows through the internal resistance of the battery to generate heat for self-heating. The disadvantage of this method is that a large amount of ineffective energy loss also occurs on the external discharge resistor, which has a greater impact on the available capacity of the battery.

[0007] A battery self-heating circuit with extremely low loss is now proposed. Its advantage is that when battery self-heating is required, the ineffective loss generated by the charge and discharge current on the self-heating circuit is extremely low, and most of the energy is generated as heat inside the battery, with high heating efficiency. Summary of the Invention

[0008] The object of the present invention is to propose an extremely low-loss battery self-heating circuit that can heat the battery (battery cell or battery pack), heat each battery cell or battery pack evenly, and has low energy loss, so as to overcome the deficiencies of uneven heating and high energy consumption of lithium batteries in the prior art. Its advantage is that when self-heating of the battery cell or battery pack is required, the loss generated on the self-heating circuit is extremely low, and most of the energy is generated as heat inside the battery cell or battery pack, with high heating efficiency.

[0009] The technical solution for achieving the object of the present invention is as follows:

[0010] An extremely low-loss battery self-heating circuit is connected to the battery to heat the battery, and is characterized in that: it includes a temperature detection circuit a, a current detection circuit b, a state flip circuit c, a full-bridge topology circuit, two half-bridge drivers, and an inductor; the input terminal 1 b1 of the current detection circuit b is connected to the positive terminal of the battery, and its output terminal OUT b3 is connected to the input terminal c1 of the state flip circuit c;

[0011] The state flip-flop circuit c has two output terminals c2 and c3 respectively connected to the IN terminals of two half-bridge circuits;

[0012] The input terminal 2 b2 of the current detection circuit b is connected to the positive terminal of the full-bridge topology circuit, and the negative terminal of the full-bridge topology circuit is connected to the negative terminal of the battery;

[0013] Two half-bridge drivers IC4 and IC5 are respectively connected to two half-bridges in the full-bridge topology circuit, and the inductor L1 is connected to the midpoint of two bridge arms.

[0014] The ground terminal a1 of the temperature detection circuit a is connected to the negative terminal of the battery, and its OUT terminal is connected to the SD terminals of two half-bridge drivers IC4 and IC5.

[0015] To achieve better technical effects, the technical features of the technical solution of the present invention can also be specifically the following technical features: 1. The temperature detection circuit consists of a temperature switch TS1 and a pull-up resistor R2. The terminal 2 of the temperature switch TS1 is connected to the terminal 1 of the pull-up resistor R2. The terminal 1 of the temperature switch TS1 serves as the ground terminal a1 of the temperature detection circuit a, and the terminal 2 of the temperature switch TS1 serves as the OUT terminal a2 of the temperature detection circuit a.

[0016] 2. The temperature detection circuit a is a thermistor or a temperature sensor or other signal processing circuits for temperature sensing. Its ground terminal is connected to the negative terminal of the battery, and its OUT terminal is connected to the SD terminals of the first half-bridge driver IC4 and the second half-bridge driver IC5.

[0017] 3. The current detection circuit b is a combined circuit of a current sampling resistor R1 and an operational amplifier IC1. The terminals 1 and 2 of the current sampling resistor R1 are respectively connected to the positive and negative terminals of the operational amplifier IC1; the terminal 1 of the current sampling resistor R1 serves as the input terminal 1 b1 of the current detection circuit b and is connected to the positive terminal of the battery, the terminal 2 of the current sampling resistor R1 serves as the input terminal 2 b2 of the current detection circuit b and is connected to the positive terminal of the full-bridge topology circuit, and the output OUT terminal of the operational amplifier IC1 serves as the output terminal b3 of the current detection circuit b and is connected to the input terminal c1 of the state flip-flop circuit c.

[0018] 4. The current detection circuit b is a current transformer or a current sensor. Its input terminal 1 b1 is connected to the positive terminal of the battery, and its input terminal 2 b2 is connected to the positive terminal of the full-bridge topology circuit; its output OUT terminal b3 is connected to the input terminal c1 of the state flip-flop circuit c.

[0019] 5. The state flip-flop circuit c is composed of a comparator IC2 and a flip-flop IC3 connected in sequence. The input terminal of the comparator IC2 serves as the input terminal c1 of the state flip-flop circuit c, and the two output terminals Q and Q' of the flip-flop IC3 serve as the two output terminals c2 and c3 of the state flip-flop circuit c.

[0020] 6. The state flip - flop circuit is a single - chip microcomputer or other logic circuits.

[0021] 7. The current detection circuit b is a combined circuit of a current sampling resistor R1 and an operational amplifier IC1. One end and the other end of the current sampling resistor R1 are respectively connected to the positive and negative terminals of the operational amplifier IC1; one end of the current sampling resistor R1 serves as the input terminal 1 of the current detection circuit, the other end of the current sampling resistor R1 serves as the input terminal 2 of the current detection circuit, and the output OUT terminal of the operational amplifier IC1 serves as the output terminal of the current detection circuit; the state flip - flop circuit c is composed of a comparator IC2 and a flip - flop IC3 connected in sequence. The input terminal of the comparator IC2 serves as the input terminal of the state flip - flop circuit, and the two output terminals Q and Q' of the flip - flop IC3 serve as the two output terminals of the state flip - flop circuit;

[0022] The full - bridge topology circuit is composed of four semiconductor switching tubes, namely a first semiconductor switching tube K1, a second semiconductor switching tube K2, a third semiconductor switching tube K3, and a fourth semiconductor switching tube K4. The S terminal of the first semiconductor switching tube K1 is connected to the D terminal of the third semiconductor switching tube K3 to form a mid - point of the H - bridge and is connected to one end of the inductor L1; the S terminal of the second semiconductor switching tube K2 is connected to the D terminal of the fourth semiconductor switching tube K4 to form another mid - point of the H - bridge and is connected to the other end of the inductor L1;

[0023] The D terminals of the first semiconductor switching tube K1 and the second semiconductor switching tube K2 are connected in parallel to the other end of the current sampling resistor R1, and one end of the current sampling resistor R1 is connected to the positive terminal of the battery B1;

[0024] The S terminals of the third semiconductor switching tube K3 and the fourth semiconductor switching tube K4 are connected in parallel to the negative terminal of the battery B1;

[0025] One end and the other end of the current sampling resistor R1 are respectively connected to the + terminal and - terminal of the operational amplifier IC1, and the OUT terminal of the operational amplifier IC1 is connected to the + terminal of the comparator; the - terminal of the comparator IC2 is connected to the reference voltage REF, and the OUT terminal of the comparator IC2 is connected to the CLK terminal of the flip - flop IC3; the T terminal of the flip - flop IC3 is connected to the power supply voltage VCC, the Q terminal of the flip - flop IC3 is connected to the IN terminal of the first half - bridge driver IC4, and the Q' terminal of the flip - flop is connected to the IN terminal of the second half - bridge driver IC5;

[0026] The HO terminal and VS terminal of the first half-bridge driver IC4 are respectively connected to the G terminal and S terminal of the first semiconductor switch K1, and the LO terminal and COM terminal of the first half-bridge driver IC4 are respectively connected to the G terminal and S terminal of the third semiconductor switch K3; the HO terminal and VS terminal of the second half-bridge driver IC5 are respectively connected to the G terminal and S terminal of the second semiconductor switch K2, and the LO terminal and COM terminal of the second half-bridge driver IC5 are respectively connected to the G terminal and S terminal of the fourth semiconductor switch K4;

[0027] The 1 terminal of the temperature switch TS1 is connected to the - terminal of the battery B1; the 2 terminal of the temperature switch TS1 is connected to the 1 terminal of the pull-up resistor R2 and is also connected to the SD terminals of the first half-bridge driver IC4 and the second half-bridge driver IC5; the 1 terminal of the pull-up resistor R2 is connected to the power supply voltage VCC.

[0028] 8. The battery is a battery cell or a battery pack.

[0029] Adopting the technical solution of the present invention has the following advantages:

[0030] 1. Utilize the heat generated by the charging and discharging current on the internal resistance of the battery to achieve self-heating and temperature rise until the battery temperature rises to a certain temperature.

[0031] 2. In the present invention, an inductor is used to replace the resistor in the prior art, so that the loss generated by the charging and discharging current on the external circuit is extremely low, and most of the energy is generated in the battery in the form of heat, with high heating efficiency;

[0032] 3. Set up a temperature detection circuit, which can accurately monitor the temperature of the battery, can start the heating circuit to work in time to heat the battery when heating is required, and stop the heating circuit from working when the temperature reaches the set value, avoiding overheating of the battery;

[0033] 4. Compared with the technology of directly short-circuiting and discharging the battery cell or battery pack through an external switch such as a MOS tube, the charging and discharging current in the technical solution of the present invention is gently controllable rather than rising sharply, and there is no short-circuit damage to the battery cell or battery pack; 5. Compared with the technology of discharging the battery cell or battery pack through an external switch such as a MOS tube and an external resistor, the external energy-consuming resistor in the technical solution of the present invention is replaced by a storage inductor, eliminating unnecessary energy loss. Description of the Drawings

[0034] Figure 1 is a schematic diagram of an embodiment of the technical solution of the ultra-low-loss battery self-heating circuit of the present invention

[0035] Figure 2 is Figure 1 the circuit schematic diagram of the embodiment of the ultra-low-loss battery self-heating circuit of the present invention shown

[0036] Figure 3 Yes Figure 2 Schematic diagram of the change of the battery charge and discharge current iB in one cycle of the battery self-heating circuit of the illustrated embodiment

[0037] Figure 4 Yes Figure 2 Schematic diagram of the change of the inductor current iL in one cycle of the battery self-heating circuit of the illustrated embodiment. The positive direction of the battery charge and discharge current iB and the positive direction of the inductor current iL are as shown Figure 1 as shown in

[0038] Battery B1 is a battery, TS1 is a temperature switch, R2 is a pull-up resistor, F1 is a fuse, R1 is a current sampling resistor, IC1 is an operational amplifier, IC2 is a comparator, IC3 is a flip-flop, IC4 is a first half-bridge driver, IC5 is a second half-bridge driver, K1 is a first semiconductor switch, K2 is a second semiconductor switch, K3 is a third semiconductor switch, K4 is a fourth semiconductor switch, and L1 is an inductor.

[0039] a is a temperature detection circuit, b is a current detection circuit, and c is a state flip-flop circuit.

[0040] Specific implementation manner: To better understand and implement the technical solution of the present invention, the following is a detailed description of an embodiment of the present invention in conjunction with the attached Figure 1-3 drawings.

[0041] As Figure 1 shown in, the extremely low-loss battery self-heating circuit in this embodiment includes a temperature detection circuit a, a current detection circuit c, a state flip-flop circuit c, a full-bridge topology circuit, two half-bridge drivers, and an inductor L1. The full-bridge topology circuit is composed of four semiconductor switches, namely, a first semiconductor switch K1, a second semiconductor switch K2, a third semiconductor switch K3, and a fourth semiconductor switch K4. The first half-bridge driver IC4 and the second half-bridge driver IC5 are respectively connected to the two half-bridges in the full-bridge topology circuit. The inductor L1 is connected to the midpoint of the two bridge arms, and the negative end of the full-bridge topology circuit is connected to the negative end of the battery.

[0042] As Figure 2 shown in, the extremely low-loss battery self-heating circuit of this embodiment specifically includes a temperature switch TS1, a pull-up resistor R2, a fuse F1, a current sampling resistor R1, an operational amplifier IC1, a comparator IC2, a flip-flop IC3, a first half-bridge driver IC4 and a second half-bridge driver IC5, four semiconductor switches, namely, a first semiconductor switch K1, a second semiconductor switch K2, a third semiconductor switch K3, and a fourth semiconductor switch K4, and an inductor L1. The battery self-heating circuit is connected to the battery (which can be a battery pack or a battery cell) B1 to heat it.

[0043] The temperature detection circuit a is composed of a temperature switch TS1 and a pull-up resistor R2. The 2 terminal of the temperature switch TS1 is connected to the 1 terminal of the pull-up resistor R2. The 1 terminal of the temperature switch TS1 is connected to the negative terminal of the battery as the ground terminal of the temperature detection circuit. The 2 terminal of the temperature switch TS1 is connected to the SD terminals of the first half-bridge driver IC4 and the second half-bridge driver IC5 as the OUT terminal of the temperature detection circuit.

[0044] The current detection circuit b is a combined circuit of a current sampling resistor R1 and an operational amplifier IC1. The 1 terminal and the 2 terminal of the resistor R1 are respectively connected to the positive and negative terminals of the operational amplifier IC1; the 1 terminal of the sampling resistor R1 is connected to the positive terminal of the battery as the input 1 terminal of the current detection circuit, the 2 terminal of the sampling resistor R1 is connected to the positive terminal of the full-bridge topology circuit as the input 2 terminal of the current detection circuit, and the output OUT terminal of the operational amplifier IC1 is connected to the input terminal of the state flip-flop circuit as the output terminal of the current detection circuit;

[0045] The state flip-flop circuit c is composed of a comparator IC2 and a flip-flop IC3 connected in sequence. The input terminal of the comparator IC2 is used as the input terminal of the state flip-flop circuit, and the two output terminals Q and Q' of the flip-flop IC3 are used as the two output terminals of the state flip-flop circuit and are respectively connected to the IN terminals of the two half-bridge circuits;

[0046] Figure 1 The connection relationships of the components of the self-heating circuit are described in detail as follows:

[0047] The full-bridge topology circuit is composed of four semiconductor switching tubes, namely the first semiconductor switching tube K1, the second semiconductor switching tube K2, the third semiconductor switching tube K3, and the fourth semiconductor switching tube K4. The S terminal of the first semiconductor switching tube K1 is connected to the D terminal of the third semiconductor switching tube K3 to form a midpoint of the H-bridge and is connected to the 1 terminal of the inductor L1; the S terminal of the second semiconductor switching tube K2 is connected to the D terminal of the fourth semiconductor switching tube K4 to form another midpoint of the H-bridge and is connected to the 2 terminal of the inductor L1;

[0048] The D terminals of the first semiconductor switching tube K1 and the second semiconductor switching tube K2 are connected in parallel to the 2 terminal of the current sampling resistor R1, and the 1 terminal of the current sampling resistor R1 is connected to the + terminal of the battery B1;

[0049] The S terminals of the third semiconductor switching tube K3 and the fourth semiconductor switching tube K4 are connected in parallel to the - terminal of the battery B1;

[0050] One end and the other end of the current sampling resistor R1 are respectively connected to the + terminal and the - terminal of the operational amplifier IC1. The OUT terminal of the operational amplifier IC1 is connected to the + terminal of the comparator. The - terminal of the comparator is connected to the reference voltage REF, and the OUT terminal of the comparator is connected to the CLK terminal of the flip-flop IC3. The T terminal of the flip-flop is connected to the power supply voltage VCC, the Q terminal of the flip-flop is connected to the IN terminal of the half-bridge driver IC4, and the Q' terminal of the flip-flop is connected to the IN terminal of the half-bridge driver IC5.

[0051] The HO terminal and the VS terminal of the first half-bridge driver IC4 are respectively connected to the G terminal and the S terminal of the first semiconductor switch K1, and the LO terminal and the COM terminal of the first half-bridge driver IC4 are respectively connected to the G terminal and the S terminal of the third semiconductor switch K3. The HO terminal and the VS terminal of the second half-bridge driver IC5 are respectively connected to the G terminal and the S terminal of the second semiconductor switch K2, and the LO terminal and the COM terminal of the second half-bridge driver IC5 are respectively connected to the G terminal and the S terminal of the fourth semiconductor switch K4.

[0052] One end of the temperature switch TS1 is connected to the - terminal of the battery B1. The other end of the temperature switch TS1 is connected to one end of the pull-up resistor R2 and simultaneously connected to the SD terminals of the first half-bridge driver IC4 and the second half-bridge driver IC5. One end of the pull-up resistor R2 is connected to the power supply voltage VCC.

[0053] Working principle:

[0054] The following further describes a battery self-heating circuit with extremely low loss provided by the present invention in combination with the accompanying drawings and embodiments.

[0055] The extremely low loss battery self-heating circuit of the present invention is realized through a temperature detection circuit, a current detection circuit, a state flip-flop circuit, a full-bridge topology circuit, and inductive energy storage.

[0056] As Figure 1 shown, four semiconductor switches form a full-bridge topology structure, and the inductor is connected to the midpoint of two bridge arms. The first semiconductor switch K1 and the fourth semiconductor switch K4 are turned on and off simultaneously, and the second semiconductor switch K2 and the third semiconductor switch K3 are turned on and off simultaneously. When the first semiconductor switch K1 and the fourth semiconductor switch K4 are turned on, the second semiconductor switch K2 and the third semiconductor switch K3 are turned off. When the first semiconductor switch K1 and the fourth semiconductor switch K4 are turned off, the second semiconductor switch K2 and the third semiconductor switch K3 are turned on, forming a discharge circuit of the battery to the inductor or a charging circuit of the inductor to the battery. The inductor L1 only plays a role in energy storage and basically does not consume energy. The charging and discharging current iB flows through the internal resistance of the battery to achieve self-heating.

[0057] The positive direction of the battery charge and discharge current iB and the positive direction of the inductor current iL are asFigure 3-4 as shown

[0058] Among them: The first half-bridge driver IC4 and the second half-bridge driver IC5 are drivers for semiconductor switching tubes, outputting the driving signal for the upper switching tube between the HO terminal and the VS terminal, and outputting the driving signal for the lower switching tube between the LO terminal and the COM terminal. The driving signal for the upper switching tube is in the same phase as the input signal at the IN terminal, the driving signal for the lower switching tube is in the opposite phase to the input signal at the IN terminal, and the driving signals for the upper and lower switching tubes are complementary.

[0059] The Q terminal and the Q' terminal of the flip-flop IC3 are also complementary, and are respectively connected to the IN terminals of the first half-bridge driver IC4 and the second half-bridge driver IC5. Therefore, when the Q terminal of the flip-flop IC3 is at a high level, the first semiconductor switching tube K1 and the fourth semiconductor switching tube K4 are turned on, and the second semiconductor switching tube K2 and the third semiconductor switching tube K3 are turned off; when the Q terminal of the flip-flop IC3 is at a low level, the first semiconductor switching tube K1 and the fourth semiconductor switching tube K4 are turned off, and the second semiconductor switching tube K2 and the third semiconductor switching tube K3 are turned on.

[0060] The SD terminals of the first half-bridge driver IC4 and the second half-bridge driver IC5 are the input terminals for the shutdown signal. When the signal at the SD terminal is at a low level, the driving signals for both the upper and lower switching tubes are turned off.

[0061] TS1 is a temperature switch, which can be installed on the surface or inside the battery. When the temperature is lower than a certain temperature, the temperature switch is turned off, and the SD terminals of the first half-bridge driver IC4 and the second half-bridge driver IC5 are pulled up to a high level by the pull-up resistor R2, the driving signals for the semiconductor switching tubes are normal, and the self-heating circuit starts to work; when the temperature is higher than a certain temperature, the temperature switch TS1 is closed, the SD terminals of the first half-bridge driver IC4 and the second half-bridge driver IC5 are at a low level, the driving signals for the semiconductor switching tubes are turned off, and the self-heating circuit stops working.

[0062] The working principle and the change process of the current after the self-heating circuit starts to work are described as follows:

[0063] As Figure 2-3 shown, the battery charge and discharge current iB flows through R1 to generate a small voltage. The voltage is amplified by the operational amplifier IC1 and output from the OUT terminal to the + terminal of the comparator IC2, and compared with the reference voltage REF at the - terminal of the comparator IC2. When it is lower than REF, the OUT terminal of the comparator IC2 remains at a low level. When it is higher than REF, the OUT terminal of the comparator IC2 generates a rising-edge pulse, which is output to the CLK terminal of the flip-flop IC3, thereby causing the levels of the Q and Q' terminals of the flip-flop IC3 to flip once.

[0064] Assume that at the initial state t0, the Q terminal of the flip-flop IC3 is at a high level. Then, the first semiconductor switch K1 and the fourth semiconductor switch K4 are turned on, and the second semiconductor switch K2 and the third semiconductor switch K3 are turned off. Thus, the battery voltage is applied across the inductor L1, and the battery is in a discharging state, with the discharging current iB increasing linearly.

[0065] At time t1, the discharging current iB increases to a level that causes a rising-edge pulse to be generated at the OUT terminal of the comparator IC2. The Q and Q' terminals of the flip-flop IC3 flip, i.e., the Q terminal outputs a low level. Therefore, the second semiconductor switch K2 and the third semiconductor switch K3 are turned on, and the first semiconductor switch K1 and the fourth semiconductor switch K4 are turned off. The inductor continues to conduct current to charge the battery B1, and the charging current iB begins to decrease linearly.

[0066] At time t2, the charging current iB decreases to zero, and the battery charging is completed. The second semiconductor switch K2 and the third semiconductor switch K3 remain turned on, and the first semiconductor switch K1 and the fourth semiconductor switch K4 remain turned off. The battery switches to the discharging state, and the discharging current iB begins to increase linearly.

[0067] At time t3, the discharging current iB increases to a level that causes a rising-edge pulse to be generated again at the OUT terminal of the comparator IC2. The Q and Q' terminals of the flip-flop IC3 flip, i.e., the Q terminal outputs a high level. Therefore, the first semiconductor switch K1 and the fourth semiconductor switch K4 are turned on, and the second semiconductor switch K2 and the third semiconductor switch K3 are turned off. The inductor continues to conduct current to charge the battery B1, and the charging current iB begins to decrease linearly.

[0068] At time t4, the charging current iB decreases to zero, and the battery charging is completed. The first semiconductor switch K1 and the fourth semiconductor switch K4 remain turned on, and the second semiconductor switch K2 and the third semiconductor switch K3 remain turned off. The battery switches to the discharging state, and the discharging current iB begins to increase linearly. Thus, a complete working cycle ends and repeats continuously.

[0069] The above charging and discharging currents generate heat on the internal resistance of the battery to achieve self-heating and temperature rise until the battery temperature rises to a certain temperature. When the above discharging current flows through the inductor, since the inductor is an energy storage element, theoretically there is no energy loss. In practice, only a very low energy loss occurs on the equivalent series resistance of the inductor. Therefore, the ineffective energy loss outside the battery is extremely low.

[0070] The heated battery B1 in the technical solution and its embodiments of the present invention can be a battery pack or a battery cell.

[0071] In this embodiment, the current detection circuit is placed at the + terminal of the battery. In practical applications, it can also be placed at the - terminal of the battery according to needs.

[0072] The various circuits and their constituent elements described in this embodiment are preferred. In practical applications:

[0073] In this embodiment, the current detection circuit can also be implemented by using a current transformer or a current sensor;

[0074] In this embodiment, the temperature detection can also be implemented by using a thermistor, a temperature sensor, and a corresponding signal processing circuit;

[0075] In this embodiment, the state flip - flop circuit can also be implemented by using a single - chip microcomputer or other logic circuits.

[0076] The extremely low - loss battery self - heating circuit of the present invention has the advantages of low energy consumption, uniform heating of the battery, safety, and high reliability. It can significantly improve the low - temperature performance of the battery and can be widely applied to batteries that require heating to improve their low - temperature performance.

[0077] The above content is a preferred embodiment of the present invention. For the structures and elements not described in detail therein, it should be understood that they are implemented by using the existing general equipment and general methods in the art.

[0078] The above - mentioned embodiments of the present invention and their accompanying drawings are only for helping to understand the technical solutions described in the present invention, and are not used to limit the technical solutions of the present invention and their protection scope. Improvements made to the technical solutions disclosed in the claims and the specification of the present invention by using equivalent technical means and equivalent equipment should be considered not to exceed the scope of the claims and the specification of the present invention.

Claims

1. A battery self-heating circuit with extremely low loss, which is connected to a battery to heat the battery, and is characterized in that: It includes a temperature detection circuit (a), a current detection circuit (b), a state flip - flop circuit (c), a full - bridge topology circuit, two half - bridge drivers, and a storage inductor (L1). The input terminal 1 (b1) of the current detection circuit (b) is connected to the positive terminal of the battery, and its output terminal OUT (b3) is connected to the input terminal (c1) of the state flip - flop circuit (c). The state flip - flop circuit (c) has two output terminals (c2, c3) respectively connected to the IN terminals of the two half - bridge circuits. The input terminal 2 (b2) of the current detection circuit (b) is connected to the positive terminal of the full - bridge topology circuit, and the negative terminal of the full - bridge topology circuit is connected to the negative terminal of the battery. The two half - bridge drivers (IC4, IC5) are respectively connected to the two half - bridges in the full - bridge topology circuit, and the storage inductor (L1) is connected to the mid - point of the two bridge arms. The ground terminal (a1) of the temperature detection circuit (a) is connected to the negative terminal of the battery, and its OUT terminal is connected to the SD terminals of the two half - bridge drivers (IC4, IC5). The temperature detection circuit (a) consists of a temperature switch (TS1) and a pull - up resistor (R2). The terminal 2 of the temperature switch (TS1) is connected to the terminal 1 of the pull - up resistor (R2). The terminal 1 of the temperature switch (TS1) serves as the ground terminal of the temperature detection circuit (a), and the terminal 2 of the temperature switch (TS1) serves as the OUT terminal of the temperature detection circuit (a). The current detection circuit (b) is a combined circuit of a current sampling resistor (R1) and an operational amplifier (IC1). The terminal 1 and terminal 2 of the current sampling resistor (R1) are respectively connected to the positive and negative terminals of the operational amplifier (IC1). The terminal 1 of the current sampling resistor (R1) serves as the input terminal 1 of the current detection circuit (b) and is connected to the positive terminal of the battery. The terminal 2 of the current sampling resistor (R1) serves as the input terminal 2 of the current detection circuit (b) and is connected to the positive terminal of the full - bridge topology circuit. The output terminal OUT of the operational amplifier (IC1) serves as the output terminal of the current detection circuit (b) and is connected to the input terminal of the state flip - flop circuit (c). The state flip - flop circuit (c) is composed of a comparator (IC2) and a flip - flop (IC3) connected in sequence. The input terminal of the comparator (IC2) serves as the input terminal of the state flip - flop circuit (c), and the two output terminals (Q, Q’) of the flip - flop (IC3) serve as the two output terminals of the state flip - flop circuit (c). The full - bridge topology circuit is composed of four semiconductor switch tubes, namely the first semiconductor switch tube (K1), the second semiconductor switch tube (K2), the third semiconductor switch tube (K3), and the fourth semiconductor switch tube (K4). The S terminal of the first semiconductor switch tube (K1) is connected to the D terminal of the third semiconductor switch tube (K3), forming a mid - point of the H - bridge and connected to the terminal 1 of the inductor (L1). The S terminal of the second semiconductor switch tube (K2) is connected to the D terminal of the fourth semiconductor switch tube (K4), forming another mid - point of the H - bridge and connected to the terminal 2 of the inductor (L1). The D terminals of the first semiconductor switch (K1) and the second semiconductor switch (K2) are connected in parallel to the 2 terminal of the current sampling resistor (R1), and the 1 terminal of the current sampling resistor (R1) is connected to the positive terminal of the battery (B1). The S terminals of the third semiconductor switch (K3) and the fourth semiconductor switch (K4) are connected in parallel to the negative terminal of the battery (B1); the 1 terminal and the 2 terminal of the current sampling resistor (R1) are respectively connected to the + terminal and the - terminal of the operational amplifier (IC1), and the OUT terminal of the operational amplifier (IC1) is connected to the + terminal of the comparator; the - terminal of the comparator (IC2) is connected to the reference voltage REF, and the OUT terminal of the comparator (IC2) is connected to the CLK terminal of the flip-flop (IC3); the T terminal of the flip-flop (IC3) is connected to the power supply voltage VCC, the Q terminal of the flip-flop (IC3) is connected to the IN terminal of the first half-bridge driver (IC4), and the Q' terminal of the flip-flop is connected to the IN terminal of the second half-bridge driver (IC5). The HO terminal and the VS terminal of the first half-bridge driver (IC4) are respectively connected to the G terminal and the S terminal of the first semiconductor switch (K1), and the LO terminal and the COM terminal of the first half-bridge driver (IC4) are respectively connected to the G terminal and the S terminal of the third semiconductor switch (K3). The HO terminal and the VS terminal of the second half-bridge driver (IC5) are respectively connected to the G terminal and the S terminal of the second semiconductor switch (K2), and the LO terminal and the COM terminal of the second half-bridge driver (IC5) are respectively connected to the G terminal and the S terminal of the fourth semiconductor switch (K4). The 1 terminal of the temperature switch (TS1) is connected to the - terminal of the battery (B1); the 2 terminal of the temperature switch (TS1) is connected to the 1 terminal of the pull-up resistor (R2) and is also connected to the SD terminals of the first half-bridge driver (IC4) and the second half-bridge driver (IC5); the 1 terminal of the pull-up resistor (R2) is connected to the power supply voltage VCC.

2. The battery self-heating circuit according to claim 1, characterized in that: The battery is a battery cell or a battery pack.

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