A battery detection circuit

Abstract

The utility model provides a kind of battery detection circuit, comprising: power input circuit, with the three-level BUCK circuit of power input circuit connection, the LLC circuit being connected with three-level BUCK circuit, still with the fluxgate sensor of LLC circuit connection and for collecting the first analog current value of second output end, respectively with three-level BUCK circuit, LLC circuit connection DSP chip and battery;Wherein, three-level BUCK circuit includes: first BUCK circuit and second BUCK circuit are mutually connected in series;LLC circuit includes: first LLC circuit, second LLC circuit and transformer, first LLC circuit includes: primary side first circuit, secondary side first circuit and secondary side second circuit, second LLC circuit includes: primary side second circuit, secondary side third circuit and secondary side fourth circuit, fluxgate sensor is also connected with the DSP chip of according to first analog current value control switch tube in three-level BUCK circuit and LLC circuit by feedback operational amplifier circuit, using this scheme, can output target voltage to battery charging.

Description

Technical Field

[0001] This utility model relates to the field of battery testing technology, and in particular to a battery testing circuit. Background Technology

[0002] Currently, the LLC single topology structure on the market is simple, but because the high voltage input voltage varies from 650V to 850V and the output voltage to the battery is in the range of DC 2.5-5V, it is difficult for the LLC topology to cover the functional range under these high input and output variation conditions. Furthermore, because the single-pole transformation ratio is too large (800V to 5V), it is difficult to output the expected or target voltage (such as 5V) to charge the battery, so the product testing efficiency is not high. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a battery detection circuit, including: a power input circuit, a three-level BUCK circuit connected to the power input circuit, an LLC circuit connected to the first output terminal of the three-level BUCK circuit, a fluxgate sensor connected to the second output terminal of the LLC circuit and used to collect the first analog current value of the second output terminal, and a DSP chip connected to the three-level BUCK circuit, the LLC circuit, and the fluxgate sensor respectively. The DSP chip is also connected to the fluxgate sensor through a feedback operational amplifier circuit to control the switching transistors in the three-level BUCK circuit and the LLC circuit according to the first analog current value, and can output the target charging voltage or the desired charging voltage of the battery to charge the battery.

[0004] In a first aspect, this utility model provides a battery detection circuit, comprising: The system includes a power input circuit, a three-level BUCK circuit connected to the power input circuit, an LLC circuit connected to the first output terminal of the three-level BUCK circuit, a fluxgate sensor connected to the second output terminal of the LLC circuit and used to acquire the first analog current value of the second output terminal, a DSP chip connected to the three-level BUCK circuit and the LLC circuit respectively, and a battery also connected to the second output terminal; wherein, The three-level BUCK circuit includes: a first BUCK circuit and a second BUCK circuit connected in series. The LLC circuit includes: a first LLC circuit, a second LLC circuit, and a transformer, wherein, The first LLC circuit includes: a primary-side first circuit, a secondary-side first circuit, and a secondary-side second circuit; the second LLC circuit includes: a primary-side second circuit, a secondary-side third circuit, and a secondary-side fourth circuit. The primary side first circuit and the primary side second circuit are connected in series, and the secondary side first circuit, secondary side second circuit, secondary side third circuit and secondary side fourth circuit are connected in parallel. The fluxgate sensor is also connected to a DSP chip via a feedback operational amplifier circuit, which controls the frequency of the switching transistors in the three-level BUCK circuit and LLC circuit according to the first analog current value.

[0005] In conjunction with the first aspect, an optional implementation further includes: A first controller for controlling the first and fourth switching transistors, and a second controller for controlling the second and third switching transistors, wherein, The first controller and the second controller are respectively connected to the DSP chip.

[0006] In conjunction with the first aspect, in one optional implementation, the first BUCK circuit includes: a first bridge arm with a first switching transistor distributed thereon and a second bridge arm with a second switching transistor distributed thereon; The second BUCK circuit includes: a third bridge arm with a third switch transistor and a fourth bridge arm with a fourth switch transistor. In this configuration, the first and fourth switches are simultaneously turned on, the second and third switches are simultaneously turned on, and the first and second switches are complementary in their conduction, as are the third and fourth switches.

[0007] In conjunction with the first aspect, in one optional implementation, the primary-side first circuit includes: a fifth bridge arm with a fifth switch transistor distributed thereon and a sixth bridge arm with a sixth switch transistor distributed thereon. The primary-side second circuit includes: a seventh bridge arm with a seventh switch and an eighth bridge arm with an eighth switch; Among them, the fifth and eighth switches are turned on simultaneously, the sixth and seventh switches are turned on simultaneously, and the fifth and sixth switches are complementary in their conduction, as are the seventh and eighth switches.

[0008] In conjunction with the first aspect, in one alternative implementation, Also includes: An ADC converter used to convert a first analog current value into a first digital current value and an analog voltage value into a digital voltage value. Feedback operational amplifier circuits include: current feedback operational amplifier circuits and voltage feedback operational amplifier circuits; The ADC converter is also connected to the fluxgate sensor, the current feedback operational amplifier circuit, and the voltage feedback operational amplifier circuit, respectively. The DSP chip is connected to the current feedback operational amplifier circuit and the voltage feedback operational amplifier circuit, respectively, to receive the first digital current value to control the duty cycle of the switching transistor in the three-level BUCK circuit, and to receive the digital voltage value to control the duty cycle of the switching transistor in the three-level BUCK circuit.

[0009] In conjunction with the first aspect, in one alternative implementation, The primary-side first circuit also includes: a first current transformer for acquiring the value of the second analog current flowing through the primary-side first circuit. The primary-side second circuit also includes: a second current transformer for acquiring the value of the third analog current flowing through the primary-side second circuit; The battery detection circuit further includes: a rectifier circuit for converting a second analog current value into a second digital current value and for converting a third analog current value into a third digital current value. The rectifier circuit is also connected to the DSP chip.

[0010] This invention provides a battery detection circuit, comprising: a power input circuit, a three-level BUCK circuit connected to the power input circuit, an LLC circuit connected to the three-level BUCK circuit, a fluxgate sensor connected to the LLC circuit and used to acquire the first analog current value of the second output terminal, a DSP chip connected to the three-level BUCK circuit and the LLC circuit respectively, and a battery; wherein, the three-level BUCK circuit includes: a first BUCK circuit and a second BUCK circuit connected in series; the LLC circuit includes: a first LLC circuit, a second LLC circuit and a transformer, the first LLC circuit includes: a primary side first circuit, a secondary side first circuit and a secondary side second circuit, the second LLC circuit includes: a primary side second circuit, a secondary side third circuit and a secondary side fourth circuit, and the fluxgate sensor is also connected to the DSP chip through a feedback operational amplifier circuit that controls the switching transistors in the three-level BUCK circuit and the LLC circuit according to the first analog current value. Using this invention, the target charging voltage of the battery can be output to charge the battery. Attached Figure Description

[0011] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Among them, 10-power input circuit, 11-three-level BUCK circuit, 111-first BUCK circuit, 112-second BUCK circuit, 12-LLC circuit, 121-first LLC circuit, 122-second LLC circuit, 13-magnetic fluxgate sensor, 14-feedback operational amplifier circuit, 141-current feedback operational amplifier circuit, 142-voltage feedback operational amplifier circuit, 15-DSP chip, 16-battery; Figure 1 This is a schematic diagram of a battery detection circuit provided by this utility model; Figure 2 This is a schematic diagram of another battery detection circuit provided by this utility model; Figure 3 This is a schematic diagram of a three-level BUCK circuit provided by this utility model; Figure 4 This is a schematic diagram of an LLC circuit provided by this utility model. Detailed Implementation

[0012] The technical solutions of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.

[0013] It should be noted that the terms "first," "second," "third," "fourth," "fifth," "sixth," "seventh," and "eighth" in this utility model are only used to distinguish different LLC circuits, BUCK circuits, switching transistors, etc., and have no other meaning, and should not limit the scope of protection of this utility model.

[0014] See Figure 1 This is a schematic diagram of a battery detection circuit provided by this utility model, as shown below. Figure 1 As shown, the battery detection circuit may include, but is not limited to: The circuit includes a power input circuit 10, a three-level BUCK circuit 11 connected to the power input circuit 10, an LLC (Inductor-Inductor-Capacitor) circuit 12 connected to the first output terminal of the three-level BUCK circuit 11, a fluxgate sensor 13 connected to the second output terminal of the LLC circuit 12 and used to acquire the first analog current value of the second output terminal, a DSP (Digital Signal Processing) chip 15 connected to the three-level BUCK circuit 11 and the LLC circuit 12 respectively, and a battery 16 also connected to the second output terminal; wherein, the second output terminal of the LLC circuit 12 is a current and voltage output terminal of the LLC circuit 12. Battery 16 has a rated voltage of 5V.

[0015] The three-level BUCK circuit 11 includes a first BUCK circuit 111 and a second BUCK circuit 113 connected in series; wherein, the three-level BUCK circuit 11 is a BUCK circuit with three different potentials (e.g., P point, O point, N point). The first BUCK circuit 111 and the second BUCK circuit 113 are different circuits.

[0016] LLC circuit 12 includes: a first LLC circuit 121, a second LLC circuit 122, and a transformer, wherein, The first LLC circuit 121 includes: a primary-side first circuit, a secondary-side first circuit, and a secondary-side second circuit; the second LLC circuit 122 includes: a primary-side second circuit, a secondary-side third circuit, and a secondary-side fourth circuit, wherein... The primary side first circuit and the primary side second circuit are connected in series, and the secondary side first circuit, secondary side second circuit, secondary side third circuit and secondary side fourth circuit are connected in parallel. The fluxgate sensor 13 is also connected to a DSP chip 15, which controls the frequency of the switching transistors in the three-level BUCK circuit 11 and LLC circuit 12 according to the first analog current value, via a feedback operational amplifier circuit 14.

[0017] The battery detection circuit includes: a power input circuit 10, a three-level BUCK circuit 11, an LLC circuit 12 connected to the first output terminal of the three-level BUCK circuit 11, a fluxgate sensor 13 connected to the second output terminal of the LLC circuit 12 and used to acquire the first analog current value of the second output terminal, a DSP chip 15 connected to the three-level BUCK circuit 11 and the LLC circuit 12 respectively, and a battery 16 also connected to the second output terminal. It may also include: A first controller for controlling the first and fourth switching transistors, and a second controller for controlling the second and third switching transistors, wherein, The first controller and the second controller are respectively connected to the DSP chip 15.

[0018] Optionally, the first BUCK circuit includes: a first bridge arm with a first switching transistor distributed thereon and a second bridge arm with a second switching transistor distributed thereon; The second BUCK circuit includes: a third bridge arm with a third switch transistor and a fourth bridge arm with a fourth switch transistor. In this configuration, the first and fourth switches are simultaneously turned on, the second and third switches are simultaneously turned on, and the first and second switches are complementary in their conduction, as are the third and fourth switches.

[0019] Optionally, the primary-side first circuit includes: a fifth bridge arm with a fifth switch and a sixth bridge arm with a sixth switch; The primary-side second circuit includes: a seventh bridge arm with a seventh switch and an eighth bridge arm with an eighth switch; Among them, the fifth and eighth switches are turned on simultaneously, the sixth and seventh switches are turned on simultaneously, and the fifth and sixth switches are complementary in their conduction, as are the seventh and eighth switches.

[0020] Optionally, the battery detection circuit includes: a power input circuit 10, a three-level BUCK circuit 11, an LLC circuit 12 connected to the first output terminal of the three-level BUCK circuit 11, a fluxgate sensor 13 connected to the second output terminal of the LLC circuit 12 and used to acquire the first analog current value of the second output terminal, a DSP chip 15 connected to the three-level BUCK circuit 11 and the LLC circuit 12 respectively, and a battery 16 also connected to the second output terminal, and may further include: An ADC converter used to convert a first analog current value into a first digital current value and an analog voltage value into a digital voltage value. The feedback operational amplifier circuit 14 includes: a current feedback operational amplifier circuit 141 and a voltage feedback operational amplifier circuit 142; The ADC converter is also connected to the fluxgate sensor 13, the current feedback operational amplifier circuit 141, and the voltage feedback operational amplifier circuit 142, respectively. The DSP chip 15 is connected to the current feedback operational amplifier circuit 141 and the voltage feedback operational amplifier circuit 142, respectively, to receive the first digital current value to control the duty cycle of the switching transistor in the three-level BUCK circuit 11, and to receive the digital voltage value to control the duty cycle of the switching transistor in the three-level BUCK circuit 11.

[0021] It should be noted that the ADC converter is used to convert the analog current value collected by the fluxgate sensor 13 into a digital current value, and also to convert the analog voltage value of the second output terminal into a digital voltage value. The current feedback operational amplifier circuit 141 is used to amplify the digital current value and feed it back to the DSP chip 15; the voltage feedback operational amplifier circuit 142 is used to amplify the digital voltage value and feed it back to the DSP chip 15. The DSP chip 15 adjusts the duty cycle of the first, second, third, and fourth switches in the three-level BUCK circuit 11 (that is, the first and second switches in the first BUCK circuit 111, and the third and fourth switches in the second BUCK circuit 112) according to the digital current value amplified by the signal fed back by the current feedback operational amplifier circuit 141, so that the second output terminal charges the battery 16 with the target current value. The DSP chip 15 controls the duty cycle of the first, second, third, and fourth switches in the three-level BUCK circuit 11 based on the amplified digital voltage value of the signal fed back by the voltage feedback operational amplifier circuit 142, so that the second output terminal charges the battery 16 with the target voltage.

[0022] For example, when the target charging current of battery 16 (which can be the ideal charging current for battery 16) is current value a (e.g., 600A), if the current output by the second output terminal of LLC circuit 12 is current value b, where b is greater than a, fluxgate sensor 13 is connected to the second output terminal and feeds back the collected current value b to DSP chip 15 through current feedback operational amplifier circuit 141. Corresponding to the received current value b, DSP chip 15 controls the reduction of the duty cycle of the switching transistor in three-level BUCK circuit 11, so that the second output terminal of LLC circuit 12 outputs the target current (e.g., 600A) to charge battery 16, where the absolute value of the difference between the magnitude of the target current and the magnitude of current value a is less than the absolute value of the difference between current value a and current value b.

[0023] When the target charging current of battery 16 is current value a, if the current output by the second output terminal of LLC circuit 12 is current value c, where c is less than a, fluxgate sensor 13 is connected to the second output terminal and feeds back the collected current value b to DSP chip 15 through current feedback operational amplifier circuit 141. Corresponding to the received current value b, DSP chip 15 controls the increase of the duty cycle of the switching transistor in the three-level BUCK circuit 11, so that the second output terminal of LLC circuit 12 outputs the target current to charge battery 16, where the absolute value of the difference between the magnitude of the target current and the magnitude of current value a is less than the absolute value of the difference between current value a and current value c.

[0024] When the target charging voltage of battery 16 (which can be the ideal charging voltage applicable to battery 16) is voltage value d (e.g., 5V), if the voltage output from the second output terminal of LLC circuit 12 is voltage value e, where e is less than d, and voltage value e is fed back to DSP chip 15 through voltage feedback operational amplifier circuit 142, DSP chip 15 controls and increases the duty cycle of the switching transistor in three-level BUCK circuit 11, so that the second output terminal of LLC circuit 12 outputs the target voltage (e.g., 5V) to charge battery 16, where the absolute value of the difference between the magnitude of the target voltage and the magnitude of voltage value d is less than the absolute value of the difference between voltage value e and voltage value d.

[0025] Optionally, the primary-side first circuit further includes: a first current transformer for acquiring the value of the second analog current flowing through the primary-side first circuit. The primary-side second circuit also includes: a second current transformer for acquiring the value of the third analog current flowing through the primary-side second circuit; The battery detection circuit further includes: a rectifier circuit for converting a second analog current value into a second digital current value and a third analog current value into a third digital current value; wherein the rectifier circuit includes: a diode and a resistor.

[0026] The rectifier circuit is also connected to the DSP chip 15.

[0027] It should be noted that the DSP chip 15 determines the first output power of the first LLC circuit 121 based on the second digital current value, and determines the second output power of the second LLC circuit 122 based on the third digital current value. When the first output power and the second output power are not equal, the DSP chip 15 controls the switching frequencies of the fifth and sixth switches in the first LLC circuit 121 and the seventh and eighth switches in the second LLC circuit 122 based on the first and second output power, so that the first output power of the first LLC circuit 121 is equal to the second output power of the second LLC circuit 122. This prevents the power difference between the first LLC circuit 121 and the second LLC circuit 122 from causing different heat generation and damaging the components in the circuit. Thus, this solution can protect the first LLC circuit 121 and the second LLC circuit 122 and extend the service life of the components in the circuit.

[0028] The following is combined with Figures 2-4 right Figure 1 The battery detection circuit in the circuit will be explained in detail, and it should be noted that... Figure 3 for Figure 2 A partial enlarged view of the three-level BUCK circuit 11. Figure 4 for Figure 2 A partially enlarged view of the LLC circuit in the image. Specifically, The three-level BUCK circuit 11 may include: a first BUCK circuit 111 and a second BUCK circuit 112. That is, the first BUCK circuit 111 includes: a first bridge arm with a switch Q3 distributed thereon and a second bridge arm with a switch Q6 distributed thereon; the second BUCK circuit 112 includes: a third bridge arm with a switch Q11 distributed thereon and a fourth bridge arm with a switch Q15 distributed thereon. Switches Q3 and Q15 are turned on simultaneously, as are switches Q6 and Q11. Switches Q3 and Q6 are complementary in their conduction, and the second and third switches are complementary in their conduction.

[0029] The three-level BUCK circuit 11 has three different potentials (e.g., ...). Figure 2 or Figure 3 A BUCK circuit with points P, O, and N (where the absolute value of the voltage difference between points P and O is equal to the absolute value of the voltage difference between points N and O).

[0030] It should be noted that the LLC circuit 12 may include, but is not limited to, a first LLC circuit 121 and a second LLC circuit 122, wherein the first LLC circuit 121 includes a primary-side first circuit, a secondary-side first circuit, and a secondary-side second circuit, and the second LLC circuit 122 includes a primary-side second circuit, a secondary-side third circuit, and a secondary-side fourth circuit. The primary side first circuit includes: a fifth bridge arm with a switch Q5 and a sixth bridge arm with a switch Q8. The primary-side second circuit includes: a seventh bridge arm with a switch Q10 distributed thereon and an eighth bridge arm with a switch Q12 distributed thereon; Among them, switch Q5 and switch Q12 are turned on simultaneously, switch Q8 and switch Q10 are turned on simultaneously, and switch Q5 and switch Q8 are complementary in conduction, and switch Q10 and switch Q12 are complementary in conduction.

[0031] Figures 1-4 This is only used to illustrate the embodiments of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0032] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should all be covered within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. A battery detection circuit, characterized in that, include: The system includes a power input circuit (10), a three-level BUCK circuit (11) connected to the power input circuit (10), an LLC circuit (12) connected to the first output terminal of the three-level BUCK circuit (11), a fluxgate sensor (13) connected to the second output terminal of the LLC circuit (12) and used to acquire the first analog current value of the second output terminal, a DSP chip (15) connected to the three-level BUCK circuit (11) and the LLC circuit (12) respectively, and a battery (16) also connected to the second output terminal; wherein, The three-level BUCK circuit (11) includes: a first BUCK circuit (111) and a second BUCK circuit (112) connected in series. The LLC circuit (12) includes: a first LLC circuit (121), a second LLC circuit (122), and a transformer, wherein, The first LLC circuit (121) includes: a primary-side first circuit, a secondary-side first circuit, and a secondary-side second circuit; the second LLC circuit (122) includes: a primary-side second circuit, a secondary-side third circuit, and a secondary-side fourth circuit, wherein, The primary side first circuit and the primary side second circuit are connected in series, and the secondary side first circuit, secondary side second circuit, secondary side third circuit and secondary side fourth circuit are connected in parallel. The fluxgate sensor (13) is also connected to the DSP chip (15) that controls the switching transistors in the three-level BUCK circuit (11) and LLC circuit (12) according to the first analog current value through the feedback operational amplifier circuit (14).

2. The battery detection circuit as described in claim 1, characterized in that, The first BUCK circuit (111) includes: a first bridge arm with a first switching transistor distributed thereon and a second bridge arm with a second switching transistor distributed thereon; The second BUCK circuit (112) includes: a third bridge arm with a third switch transistor distributed thereon and a fourth bridge arm with a fourth switch transistor distributed thereon; In this configuration, the first and fourth switches are simultaneously turned on, the second and third switches are simultaneously turned on, and the first and second switches are complementary in their conduction, as are the third and fourth switches.

3. The battery detection circuit as described in claim 2, characterized in that, Also includes: A first controller for controlling the first and fourth switching transistors, and a second controller for controlling the second and third switching transistors, wherein, The first controller and the second controller are respectively connected to the DSP chip (15).

4. The battery detection circuit as described in claim 1, characterized in that, The primary side first circuit includes: a fifth bridge arm with a fifth switch transistor distributed thereon and a sixth bridge arm with a sixth switch transistor distributed thereon; The primary-side second circuit includes: a seventh bridge arm with a seventh switch and an eighth bridge arm with an eighth switch; Among them, the fifth and eighth switches are turned on simultaneously, the sixth and seventh switches are turned on simultaneously, and the fifth and sixth switches are complementary in their conduction, as are the seventh and eighth switches.

5. The battery detection circuit as described in claim 1, characterized in that, Also includes: An ADC converter used to convert a first analog current value into a first digital current value and an analog voltage value into a digital voltage value. The feedback operational amplifier circuit (14) includes: a current feedback operational amplifier circuit (141) and a voltage feedback operational amplifier circuit (142). The ADC converter is also connected to the fluxgate sensor (13), the current feedback operational amplifier circuit (141), and the voltage feedback operational amplifier circuit (142), respectively. The DSP chip (15) is connected to the current feedback operational amplifier circuit (141) and the voltage feedback operational amplifier circuit (142), respectively, to receive the first digital current value to control the duty cycle of the switching transistor in the three-level BUCK circuit (11), and to receive the digital voltage value to control the duty cycle of the switching transistor in the three-level BUCK circuit (11).

6. The battery detection circuit as described in claim 4, characterized in that, The primary-side first circuit also includes: a first current transformer for acquiring the value of the second analog current flowing through the primary-side first circuit. The primary-side second circuit also includes: a second current transformer for acquiring the value of the third analog current flowing through the primary-side second circuit; The battery detection circuit further includes: a rectifier circuit for converting a second analog current value into a second digital current value and for converting a third analog current value into a third digital current value. The rectifier circuit is also connected to the DSP chip (15).

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