Charging device, method for controlling charging of charging device, and vehicle

Abstract

A charging device, a vehicle, and a method for controlling charging of the charging device are provided. The charging device (1) includes a first DC conversion module (10) that converts a DC current signal output from a power battery (16) into a DC current signal required for a storage battery (15) and includes a first half-bridge LLC circuit unit (11) and a second half-bridge LLC circuit unit (12) arranged in parallel, and a control module (20) connected to the first half-bridge LLC circuit unit (11) and the second half-bridge LLC circuit unit (12), respectively, that obtains a total output current of the first DC conversion module (10) and controls the first half-bridge LLC circuit unit (11) and the second half-bridge LLC circuit unit (12) to alternately operate when the total output current is less than a current threshold. The charging device (1) can reduce switch losses and improve charging efficiency.

Description

Technical Field

[0001] (Cross - reference to related applications) This disclosure is based on and claims priority to a Chinese patent application with application number 202011091549.8 and filing date October 13, 2020, and all of its contents are hereby incorporated by reference into this disclosure.

[0002] This disclosure relates to the technical field of vehicles, and particularly to a charging device, a method for controlling the charging of the charging device, and a vehicle.

Background Art

[0003] With the commercialization progress of vehicles, the DC - DC converter (Direct current - Direct current converter) and OBC (On board charger) of vehicles have already become one of the important components of vehicles.

[0004] As the charging demand is increasing and the required charging time is getting shorter, high - power charging devices have emerged. In some high - power charging devices, the DC - DC converter includes two half - bridge LLC (Logical Link Control, resonant circuit), and in order to supply power to the battery and low - voltage electrical products, the parallel output voltage is 13.8V.

[0005] However, the power operation range of the DC - DC converter is 0 - 2500W, and since its switching element is always in a high - frequency operating state, the loss of the switch is high, which affects the efficiency.

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of this disclosure is to solve at least one of the technical problems in the prior art. For this reason, a first object of this disclosure is to provide a charging device that can reduce the loss of the switch and improve the charging efficiency.

[0007] The second object of the present disclosure is to provide a vehicle.

[0008] The third object of the present disclosure is to provide a method for controlling the charging of a charging device.

Means for Solving the Problems

[0009] In order to achieve the above object, an embodiment of the first aspect of the present disclosure provides a charging device, which converts a DC current signal output from a power battery into a DC current signal required by a storage battery, and includes a first DC conversion module including a first half-bridge LLC circuit unit and a second half-bridge LLC circuit unit installed in parallel, and a control module connected to the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit respectively, obtaining the total output current of the first DC conversion module, and when the total output current is smaller than a current threshold, controlling the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate alternately.

[0010] According to the charging device according to the embodiment of the present disclosure, a first half-bridge LLC circuit unit and a second half-bridge LLC circuit unit connected in parallel to the first DC conversion module are installed, and the control module controls the operating states of the two half-bridge LLC circuit units based on the total output current of the first DC conversion module. When the total output current is smaller than the current threshold, the two half-bridge LLC circuit units are controlled to operate alternately, that is, the two half-bridge LLC circuit units are not allowed to operate simultaneously. Half bridge It is possible to avoid that the switches of the entire LLC circuit unit are always in a high-frequency operating state, reduce the loss of the switch elements in the circuit unit, and improve the charging efficiency.

[0011] In some embodiments, when the control module alternately operates the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit, it controls the first half-bridge LLC circuit unit to operate, records the first operation time of the first half-bridge LLC circuit unit, and when the first operation time reaches a time threshold, switches to control the second half-bridge LLC circuit unit to operate, and records the second operation time of the second half-bridge LLC circuit unit. When the second operation time reaches the time threshold, it switches to control the first half-bridge LLC circuit unit to operate, and this process is executed cyclically. By cyclically executing this control process, the alternating operation of the two half-bridge LLC circuit units is realized, the temperature balance of the two half-bridge LLC circuit units is achieved, the temperature rise caused by the long-term operation of one of the half-bridge LLC circuit units is avoided, and the charging safety is guaranteed.

[0012] In some embodiments, when the total output current is greater than or equal to the current threshold, the control module further controls the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate simultaneously. By comparing the magnitude of the total output current with the current threshold and controlling the operating states of the two half-bridge LLC circuit units when a large current is output, a higher charging effect can be achieved.

[0013] In some embodiments, when the control module controls the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate simultaneously, the switch transistors of the first half-bridge LLC circuit unit and the switch transistors of the second half-bridge LLC circuit unit are interleaved and controlled with a difference in a predetermined phase angle. When a large current is output, by controlling the switch transistors of the first half-bridge LLC circuit unit and the switch transistors of the second half-bridge LLC circuit unit to operate in an interleaved manner at a predetermined phase angle, the object of reducing the output ripple current is achieved.

[0014] In some embodiments, the first half-bridge LLC circuit unit includes a first switch transistor and a second switch transistor. The first switch transistor has a first end connected to the first end of the power battery, a second end connected to the first end of the second switch transistor, and a control end connected to the control module. The second switch transistor has a second end connected to the second end of the power battery and a control end connected to the control module. There is a first node between the second end of the first switch transistor and the first end of the second switch transistor. The first switch transistor and the second switch transistor, a first capacitor and a first inductor. The first capacitor has a first end connected to the first node and a second end connected to the first end of the first inductor. The first transformer includes a first primary coil, a first secondary coil, and a second secondary coil. The first end of the first primary coil is connected to the second end of the first inductor, and the second end is connected to the second end of the second switch transistor. The second end of the first secondary coil and the first end of the second secondary coil are connected to form a first common end, and the first common end is connected to the second end of the storage battery. The third switch transistor and the fourth switch transistor. The first end of the third switch transistor is connected to the first end of the first secondary coil, the second end is connected to the first end of the storage battery, and the control end is connected to the control module. The first end of the fourth switch transistor is connected to the second end of the second secondary coil, the second end is connected to the second end of the third switch transistor and the first end of the storage battery, and the control end is connected to the control module. By controlling the two half-bridge LLC circuit units to operate respectively, each switch transistor is not in an operating state, and the loss of the switch transistor in the half-bridge LLC circuit unit is reduced.

[0015] In some embodiments, the second half-bridge LLC circuit unit includes a fifth switch transistor and a sixth switch transistor. The fifth switch transistor has its first end connected to the first end of the power battery, its second end connected to the first end of the sixth switch transistor, and its control end connected to the control module. The sixth switch transistor has its second end connected to the second end of the power battery and its control end connected to the control module. There is a second node between the second end of the fifth switch transistor and the first end of the sixth switch transistor. The second half-bridge LLC circuit unit further includes a fifth switch transistor and a sixth switch transistor, a second capacitor and a second inductor. The first end of the second capacitor is connected to the second node, and the second end is connected to the first end of the second inductor. The second transformer includes a second primary coil, a third secondary coil, and a fourth secondary coil. The first end of the second primary coil is connected to the second end of the second inductor, and the second end is connected to the second end of the first transformer, the second end of the second switch transistor, and the second end of the sixth switch transistor respectively. The second end of the third secondary coil and the first end of the fourth secondary coil are connected to form a second common end, and the second common end is connected to the second end of the storage battery. The second half-bridge LLC circuit unit further includes a seventh switch transistor and an eighth switch transistor. The first end of the seventh switch transistor is connected to the first end of the third secondary coil, the second end is connected to the first end of the storage battery, and the control end is connected to the control module. The first end of the eighth switch transistor is connected to the second end of the fourth secondary coil, and the second end is connected to the second end of the seventh switch transistor and the first end of the storage battery respectively, and the control end is connected to the control module. By controlling the two half-bridge LLC circuit units to operate respectively, each switch transistor is not in an operating state, thereby reducing the loss of the switch transistors in the half-bridge LLC circuit unit.

[0016] In some embodiments, the first DC conversion module further includes a filtering unit having a first end connected to the first end of the storage battery and a second end connected to the second end of the storage battery.

[0017] In some embodiments, the charging device further includes a filtering module having a first end connected to an AC power source, a PFC circuit module that performs power factor correction on the input AC current to output a DC current signal after power factor correction, and at least includes three-phase bridge arms each of which is connected to the second end of the filtering module by a power inductor, and a second DC conversion module having an input end connected to the output end of the PFC circuit module and an output end connected to the power battery.

[0018] To achieve the above object, an embodiment of the second aspect of the present disclosure provides a vehicle including a storage battery, a power battery, and the charging device described in the above embodiments respectively connected to the storage battery and the power battery.

[0019] According to the vehicle according to the embodiment of the present disclosure, by charging the vehicle using the charging device described in the above embodiment and alternately operating two half-bridge LLC circuit units, that is, by controlling so that the two half-bridge LLC circuit units do not operate simultaneously, it is possible to avoid that the switches of the entire half-bridge LLC circuit unit are always in a high-frequency operating state, reduce the loss of the switch elements in the circuit unit, and improve the charging efficiency.

[0020] To achieve the above object, an embodiment of the third aspect of the present disclosure provides a method for controlling the charging of a charging device. The charging device includes a first DC conversion module that converts a DC current signal output from a power battery into a DC current signal required by a storage battery, and includes a first half-bridge LLC circuit unit and a second half-bridge LLC circuit unit installed in parallel. The method includes: obtaining the total output current of the first DC conversion module; determining whether the total output current is less than a current threshold; and when the total output current is less than the current threshold, controlling the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate alternately.

[0021] According to the method for controlling the charging of a charging device according to an embodiment of the present disclosure, based on the relationship between the total output current and the current threshold, the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit are made to operate alternately, that is, by controlling so that the two half-bridge LLC circuit units do not operate simultaneously, it is possible to avoid that the switches of the entire half-bridge LLC circuit unit are always in a high-frequency operating state, reduce the loss of the switching elements in the circuit unit, and improve the charging efficiency.

[0022] In some embodiments, the step of controlling the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate alternately includes: controlling the first half-bridge LLC circuit unit to operate, recording the first operating time of the first half-bridge LLC circuit unit, and when the first operating time reaches a time threshold, switching to control the second half-bridge LLC circuit unit to operate, and recording the second operating time of the second half-bridge LLC circuit unit, and when the second operating time reaches the time threshold, switching to control the first half-bridge LLC circuit unit to operate, and cyclically executing such a process.

[0023] In some embodiments, the method further includes controlling the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate simultaneously when the total output current is greater than or equal to the current threshold.

[0024] In some embodiments, the step of controlling the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate simultaneously includes interleaving control of the switch transistors of the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit with a difference in a predetermined phase angle.

[0025] Additional aspects and advantages of the present disclosure will be partly shown in the following description, partly become apparent in the following description, or be grasped by implementing the present disclosure.

Brief Description of the Drawings

[0026] The above and / or additional aspects and advantages of the present disclosure will become apparent and be more easily understood by describing embodiments with reference to the following drawings.

[0027]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0028] Hereinafter, embodiments of the present disclosure will be described in detail. The embodiments described with reference to the drawings are exemplary. Hereinafter, embodiments of the present disclosure will be described in detail.

[0029] Hereinafter, a charging device according to an embodiment of the present disclosure will be described with reference to FIG. 1.

[0030] FIG. 1 is a schematic diagram of a charging device according to an embodiment of the present disclosure and its connection. As shown in FIG. 1, the charging device 1 of the embodiment of the present disclosure includes a filtering module 19, a PFC circuit module 30, and a second DC conversion module 21. The first end of the filtering module 19 is connected to an AC power supply. The PFC circuit module 30 performs power factor correction on the input AC current and outputs a DC current signal after power factor correction. Each phase bridge arm includes at least a three-phase bridge arm connected to the second end of the filtering module 19 by a power inductor 23. The input end of the second DC conversion module 21 is connected to the output end of the PFC circuit module 30, and the output end is connected to the power battery 16.

[0031] In an embodiment, when charging a vehicle using the charging device 1, the AC power supply enters the filtering module 19. The filtering module 19 performs filtering processing on the input AC power supply, filters out the extra interference electrical signals in the AC power supply. The AC power supply enters the PFC circuit module 30 after being filtered. The PFC circuit module 30 includes switch transistors Q1 to Q6, performs power factor correction on the AC current, and outputs a DC current signal. The DC current signal enters the second DC conversion module 21. The second DC conversion module 21 includes elements such as switch transistors Q7 to Q14 and a transformer. Based on the second DC conversion module 21, the DC current signal is obtained, and in order to provide the DC current signal necessary to realize the charging of the storage battery, DC conversion processing is performed on the DC current signal.

[0032] As shown in FIGS. 1 and 2, the charging device 1 according to an embodiment of the present disclosure further includes a first DC conversion module 10 and a control module 20. The first DC conversion module 10 converts a DC current signal output from the power battery 16 into a DC current signal required by the storage battery 15.

[0033] Specifically, after performing DC conversion processing on the DC current signal by the second DC conversion module 21, it is charged to the power battery 16. When charging the storage battery, the power battery 16 outputs a DC current signal, and the first DC conversion module 10 converts the DC current signal output from the power battery 16 into a DC current signal required by the storage battery to charge the storage battery 15.

[0034] In an embodiment of the present disclosure, the first DC conversion module 10 includes a first half-bridge LLC circuit unit 11 and a second half-bridge LLC circuit unit 12 installed in parallel. The control module 20 is connected to the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 respectively, obtains the total output current of the first DC conversion module 10, and when the total output current is smaller than the current threshold, controls the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 to operate alternately. That is, the control module 20 monitors the magnitude of the obtained total output current to alternately operate the two half-bridge LLC circuit units.

[0035] In the embodiment, as shown in FIG. 2, the output current of the first half-bridge LLC circuit unit 11 is denoted as, for example, IoutM1, the output current of the second half-bridge LLC circuit unit 12 is denoted as, for example, IoutM2, the total output current of the first DC conversion module 10 is denoted as, for example, Iout, the real-time temperature of the first half-bridge LLC circuit unit is denoted as, for example, T1, the real-time temperature of the second half-bridge LLC circuit unit 12 is denoted as, for example, T2, and the control module 20Based on the total output current Iout, it controls the operating states of the two half-bridge LLC circuit units. That is, when charging the battery 15, by default, first the first half-bridge LLC circuit unit is operated, and the total output current Iout is detected in real time. A current threshold is pre-stored in the control module 20. When the total output current Iout is smaller than the current threshold, for example, when Iout < Imax / 2, the control module 20 controls the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 to operate alternately. While detecting the total output currents of the two half-bridge LLC circuit units, it is necessary to consider the influence of temperature on the two half-bridge LLC circuit units. By switching to make the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 operate alternately, it is avoided that the switching elements of the two half-bridge LLC circuit units are always in a high-frequency operating state, balance the temperatures of the two half-bridge LLC circuit units, reduce the losses of the switching elements in the switch unit, and improve the charging efficiency.

[0036] According to the charging device 1 according to the embodiment of the present disclosure, the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 connected in parallel to the first DC conversion module 10 are installed. The control module 20 controls the operating states of the two half-bridge LLC circuit units based on the total output current of the first DC conversion module 10. When the total output current is smaller than the current threshold, the two half-bridge LLC circuit units are controlled to operate alternately, that is, the two half-bridge LLC circuit units are not allowed to operate simultaneously, so as to avoid that the entire half-bridge LLC circuit unit is always in a high-frequency operating state, reduce the losses of the switching elements in the circuit unit, achieve the purpose of balancing the temperature by the alternating operation, and improve the charging efficiency.

[0037] In some embodiments, as shown in FIG. 2, when the control module 20 controls the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 to operate alternately based on the total output current Iout, when it detects that the total output current Iout is less than the current threshold Imax / 2, it controls the first half-bridge LLC circuit unit 11 to operate, and records the first operation time of the first half-bridge LLC circuit unit 11, for example, t1, compares the first operation time t1 with the time threshold, for example, S, and when the first operation time t1 reaches the time threshold S, it switches to control the second half-bridge LLC circuit unit 12 to operate, and records the second operation time of the second half-bridge LLC circuit unit 12, for example, t2, compares the second operation time t2 with the time threshold S, and when the second operation time t2 reaches the time threshold S, it switches again to control the first half-bridge LLC circuit unit to operate. By executing this control process cyclically, the alternating operation of the two half-bridge LLC circuit units is realized, the temperature balance of the two half-bridge LLC circuit units is achieved, the temperature rise caused by the long-time operation of one of the half-bridge LLC circuit units is avoided, and the charging safety is guaranteed.

[0038] In some embodiments, since the total output current Iout changes continuously, in order to ensure the charging efficiency, the total output current Iout is continuously detected. Because the magnitudes of the total output current Iout are different, the controls for the two half-bridge LLC circuit units are also different. For example, when the control module 20 detects that the total output current Iout is greater than or equal to the current threshold Imax / 2, it controls the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 to operate simultaneously, that is, controls the two half-bridge LLC circuit units to operate simultaneously, and by comparing the magnitude of the total output current Iout with the current threshold Imax / 2, the operating states of the two half-bridge LLC circuit units are controlled to ensure the charging effect.

[0039] In some embodiments, the total output current Iout is the current threshold Imax / 2 The above is allIn the case where a large current is output, that is, when a large current is output, the control module 20 controls the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 to operate simultaneously, and sets the frequency of the switch transistors of the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12, for example, F, and interleaves the switch transistors of the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 with a difference in a predetermined phase angle. For example, the switch transistors of the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12 are interleaved with a 90° difference to achieve the purpose of reducing the output ripple current.

[0040] In some embodiments, as shown in FIGS. 1 and 2, the first half-bridge LLC circuit unit 11 includes a first switch transistor Q15, a second switch transistor Q16, a first capacitor C1, a first inductor IcM1, a first transformer 14, a third switch transistor Q19, and a fourth switch transistor Q20. The first switch transistor Q15 has its first end connected to the first end of the power battery 16, its second end connected to the first end of the second switch transistor Q16, and its control end connected to the control module 20. The second switch transistor Q16 has its second end connected to the second end of the power battery 16 and its control end connected to the control module 20. There is a first node a between the second end of the first switch transistor Q15 and the first end of the second switch transistor Q16. For the first capacitor C1 and the first inductor IcM1, the first capacitor C1 has its first end connected to the first node a and its second end connected to the first end of the first inductor IcM1. The first transformer 14 includes a first primary coil L11, a first secondary coil L12, and a second secondary coil L13. The first primary coil L11 has its first end connected to the second end of the first inductor IcM1 and its second end connected to the second end of the second switch transistor Q16. The second end of the first secondary coil L12 and the first end of the second secondary coil L13 are connected to form a first common end, and the first common end is connected to the second end of the storage battery 15. For the third switch transistor Q19 and the fourth switch transistor Q20, the third switch transistor Q19 has its first end connected to the first end of the first secondary coil L12, its second end connected to the first end of the storage battery 15, and its control end connected to the control module 20. The fourth switch transistor Q20 has its first end connected to the second end of the second secondary coil L13, its second end connected to the second end of the third switch transistor Q19 and the first end of the storage battery 15, and its control end connected to the control module 20.Based on the magnitude of the total output current Iout of the first DC conversion module 10, the control module 20 controls the switch states of each switch transistor to alternately operate the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12, so that when the first half-bridge LLC circuit unit 11 operates within different power ranges, it is possible to avoid each of its switch transistors always being in an operating state, and reduce the losses of the switch transistors in the first half-bridge LLC circuit unit 11.

[0041] In some embodiments, as shown in FIG. 2, the second half-bridge LLC circuit unit 12 includes a fifth switch transistor Q17, a sixth switch transistor Q18, a second capacitor C2, a second inductor IcM2, a second transformer 17, a seventh switch transistor Q21, and an eighth switch transistor Q22. The fifth switch transistor Q17 has its first end connected to the first end of the power battery 16, its second end connected to the first end of the sixth switch transistor Q18, and its control end connected to the control module 20. The sixth switch transistor Q18 has its second end connected to the second end of the power battery 16 and its control end connected to the control module 20. There is a second node b between the second end of the fifth switch transistor Q17 and the first end of the sixth switch transistor Q18. The second capacitor C2 has its first end connected to the second node b and its second end connected to the first end of the second inductor IcM2. The second transformer 17 includes a second primary coil L14, a third secondary coil L15, and a fourth secondary coil L16. The first end of the second primary coil L14 is connected to the second end of the second inductor IcM2, and the second end is respectively connected to the second end of the first transformer 14, the second end of the second switch transistor Q16, and the second end of the sixth switch transistor Q18. The second end of the third secondary coil L15 and the first end of the fourth secondary coil L16 are connected to form a second common end, and the second common end is connected to the second end of the storage battery 15. The seventh switch transistor Q21 has its first end connected to the first end of the third secondary coil L15, its second end connected to the first end of the storage battery 15, and its control end connected to the control module 20. The eighth switch transistor Q22 has its first end connected to the second end of the fourth secondary coil L16, and its second end is respectively connected to the second end of the seventh switch transistor Q21 and the first end of the storage battery 15, and its control end is connected to the control module 20.Based on the magnitude of the current value of the received total output current Iout, the control module 20 controls the operating states of the main conversion unit M1 and the sub-conversion unit M2, controls the switch states of each switch transistor, and alternately operates the first half-bridge LLC circuit unit 11 and the second half-bridge LLC circuit unit 12. When the second half-bridge LLC circuit unit 12 operates within a different power range, it is possible to avoid all the switch transistors being in an operating state, thereby reducing the losses of the switch transistors in the second half-bridge LLC circuit unit 12.

[0042] In some embodiments, as shown in FIG. 2, the first DC conversion module 10 further includes a filtering unit 18 whose first end is connected to the first end of the battery 15 and whose second end is connected to the second end of the battery 15. When charging using the charging device 1, the filtering unit 18 performs filtering processing on the DC current signal required by the battery, filters out excess interference signals, and improves the charging efficiency.

[0043] In short, according to the charging device 1 according to the embodiments of the present disclosure, there are a first half-bridge LLC circuit unit 11 and a second half-bridge LLC circuit unit 12 installed in parallel. The control module 20 controls the operating states of the two half-bridge LLC circuit units based on the total output current of the first DC conversion module 10. When the total output current is smaller than the current threshold, the two half-bridge LLC circuit units are alternately operated, that is, the two half-bridge LLC circuit units are controlled not to operate simultaneously, thereby avoiding the entire half-bridge LLC circuit unit always being in a high-frequency operating state, reducing the losses of the switch elements in the circuit unit, and improving the charging efficiency.

[0044] Hereinafter, a vehicle according to an embodiment of the second aspect of the present disclosure will be described with reference to the drawings.

[0045] FIG. 3 is a block diagram of a vehicle according to an embodiment of the present disclosure. As shown in FIG. 3, the vehicle 3 of the embodiment of the present disclosure includes a storage battery 15, a power battery 16, and the charging device 1 described in the above embodiment. The charging device 1 is connected to the storage battery 15 and the power battery 16 respectively.

[0046] According to the vehicle 3 according to the embodiment of the present disclosure, the vehicle 3 is charged using the charging device 1 described in the above embodiment, and the two half-bridge LLC circuit units are alternately operated, that is, the two half-bridge LLC circuit units are controlled so as not to be operated simultaneously, thereby avoiding that the entire half-bridge LLC circuit unit is always in a high-frequency operating state, reducing the loss of the switching element in the circuit unit, and improving the charging efficiency.

[0047] Based on the charging device described in the above embodiment, a method for controlling the charging of the charging device is described. The charging device converts the DC current signal output from the power battery into a DC current signal required by the storage battery, and includes a first DC conversion module including a first half-bridge LLC circuit unit and a second half-bridge LLC circuit unit installed in parallel. By controlling the operating states of the two half-bridge LLC circuit units, damage to the switching element in the circuit is reduced, and the influence on efficiency is mitigated.

[0048] Hereinafter, with reference to the drawings, a method for controlling the charging of a charging device according to an embodiment of the third aspect of the present disclosure will be described.

[0049] FIG. 4 is a flowchart of a method for controlling the charging of a charging device according to an embodiment of the present disclosure. As shown in FIG. 4, the method for controlling the charging of the charging device according to the embodiment of the present disclosure includes at least step S1, step S2, and step S3.

[0050] In step S1, the total output current of the first DC conversion module is obtained.

[0051] In an embodiment, when charging a vehicle using a charging device, the magnitude of the total output current is associated with the operating states of two half-bridge LLC circuit units. The power battery outputs a direct current signal, and the direct current signal passes through a first direct current conversion module. The first direct current conversion module converts the direct current signal, Control module and obtains the total output current of the direct current conversion module.

[0052] In step S2, it is determined whether the total output current is less than the current threshold.

[0053] In an embodiment, a current threshold Imax / 2 is pre-stored in the control module. The control module continuously detects the total output current Iout of the direct current conversion module, and compares the total output current Iout with the current threshold Imax / 2 to determine the relationship between the magnitudes of the two current values.

[0054] In step S3, when the total output current is less than the current threshold, control is performed to alternately operate the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit.

[0055] In an embodiment, based on the magnitudes of the total output current Iout and the current threshold Imax / 2, the operating states of the first half-bridge LLC circuit unit and the second half-bridge LLC are determined. When the total output current Iout is less than the current threshold Imax / 2, the control module controls the two half-bridge LLC circuit units to alternately operate, thereby avoiding the two half-bridge LLC circuit units from always being in a high-frequency operating state and reducing the loss of the switching elements in the circuit unit.

[0056] According to the method for controlling the charging of a charging device according to an embodiment of the present disclosure, based on the relationship between the total output current and the current threshold, the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit are alternately operated, that is, by controlling so that the two half-bridge LLC circuit units do not operate simultaneously, it is possible to avoid that the entire half-bridge LLC circuit unit is always in a high-frequency operating state, reduce the loss of the switching element in the circuit unit, and improve the charging efficiency.

[0057] In some embodiments, when the total output current Iout is less than the current threshold Imax / 2, the control module controls the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to alternately operate cyclically. When it is detected that the total output current Iout is less than the current threshold Imax / 2, the first half-bridge LLC circuit unit is controlled to operate, and the first operating time t1 of the first half-bridge LLC circuit unit is recorded. The first operating time t1 is compared with the time threshold S. When the first operating time t1 reaches the time threshold S, the second half-bridge LLC circuit unit is switched to operate, and the second operating time t2 of the second half-bridge LLC circuit unit is recorded. The second operating time t2 is compared with the time threshold S. When the second operating time t2 reaches the time threshold S, the first half-bridge LLC circuit unit is switched to operate again. By cyclically executing the control process, the alternating operation of the two half-bridge LLC circuit units is realized, the temperature balance of the two half-bridge LLC circuit units is achieved, the temperature rise caused by the long-time operation of one of the half-bridge LLC circuit units is avoided, and the charging safety is guaranteed.

[0058] In some embodiments, the total output current Iout is the current threshold Imax / 2When the above conditions are met, control is performed to operate the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit simultaneously, compare the magnitude of the total output current Iout with the current threshold Imax / 2, and control the operating states of the two half-bridge LLC circuit units, thereby achieving a higher charging effect.

[0059] In some embodiments, when a large current is output, the control module controls the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit At the same time to operate, and sets the frequency, for example F, of the switch transistors of the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit, and controls the switch transistors of the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to perform interleaved operation with a difference of a predetermined angle, for example a 90° difference, thereby achieving the purpose of reducing the output ripple current.

[0060] Hereinafter, with reference to FIG. 5, a method for controlling the charging of a charging device according to an embodiment of the present disclosure will be described.

[0061] As shown in FIG. 5, it is a flowchart of a method for controlling the charging of a charging device according to an embodiment of the present disclosure.

[0062] In step S11, the charging device is initialized and powered on.

[0063] In step S12, the first half-bridge LLC circuit unit starts to operate.

[0064] In step S13, Total output current it is determined whether it is less than the current threshold. If it is less than the current threshold, step S14 is executed; if it is not less than the current threshold, step S15 is executed.

[0065] In step S14, control is performed to operate the first half-bridge LLC circuit unit, and the first operation time of the first half-bridge LLC circuit unit is recorded.

[0066] In step S15, control is performed to simultaneously operate the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit.

[0067] In step S16, it is determined whether the first operation time exceeds a time threshold. If it exceeds the time threshold, step S17 is executed; if it does not exceed the time threshold, step S16 is continuously executed.

[0068] In step S17, the operation is switched to operate the second half-bridge LLC circuit unit, and the second operation time of the second half-bridge LLC circuit unit is recorded.

[0069] In step S18, it is determined whether the second operation time reaches the time threshold. If it reaches the time threshold, step S19 is executed; if it does not reach the time threshold, step S18 is continuously executed.

[0070] In step S19, the operation is switched to operate the first half-bridge LLC circuit unit.

[0071] In step S20, the switching frequencies of the first half-bridge LLC circuit unit Torque and the second half-bridge LLC circuit unit are set.

[0072] In step S21, the switch transistors of the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit are controlled to perform interleaved operation at a predetermined Phase angle Difference thereby.

[0073] In short, according to the method for controlling the charging of the charging device according to the embodiments of the present disclosure, based on the relationship between the total output current and the current threshold, the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit are alternately operated, that is, the two half-bridge LLC circuit units are controlled not to operate simultaneously, so as to avoid the entire half-bridge LLC circuit unit always being in a high-frequency operating state, reduce the loss of the switching element in the circuit unit, and improve the charging efficiency.

[0074] In the description of this specification, referring to the description of terms such as "one embodiment", "some embodiments", "exemplary embodiments", "examples", "specific examples", or "some examples", etc., means that the specific features, configurations, materials, or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present disclosure. In this specification, the exemplary expressions of the above terms are not necessarily limited to the same embodiment or example.

[0075] Although the embodiments of the present disclosure have been shown and described, those skilled in the art can make various changes, modifications, substitutions, and deformations to these embodiments without departing from the principles and spirit of the present disclosure, and the scope of the present disclosure is limited by the scope of the claims and their equivalent scope.

Claims

Claim 1 A first DC conversion module including a first half-bridge LLC circuit unit and a second half-bridge LLC circuit unit installed in parallel, which convert a DC current signal output from a power battery into a DC current signal required by a storage battery; a control module connected to the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit respectively, obtaining the total output current of the first DC conversion module, and when the total output current is smaller than a current threshold, controlling the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate alternately; The first half-bridge LLC circuit unit includes: a first switch transistor and a second switch transistor, wherein the first switch transistor has a first end connected to a first end of the power battery, a second end connected to a first end of the second switch transistor, and a control end connected to the control module, and the second switch transistor has a second end connected to a second end of the power battery and a control end connected to the control module, and there is a first node between the second end of the first switch transistor and the first end of the second switch transistor; a first capacitor and a first inductor, wherein the first capacitor has a first end connected to the first node and a second end connected to a first end of the first inductor; a first transformer including a first primary coil, a first secondary coil and a second secondary coil, wherein the first primary coil has a first end connected to a second end of the first inductor and a second end connected to a second end of the second switch transistor, and the second end of the first secondary coil and the first end of the second secondary coil are connected to form a first common end, and the first common end is connected to a second end of the storage battery. A third switch transistor and a fourth switch transistor, wherein the first end of the third switch transistor is connected to the first end of the first secondary coil, the second end is connected to the first end of the battery, and the control end is connected to the control module; the first end of the fourth switch transistor is connected to the second end of the second secondary coil, the second end is connected to the second end of the third switch transistor and the first end of the battery, and the control end is connected to the control module, including a third switch transistor and a fourth switch transistor, The current threshold value is Half of the maximum value of the total output current of the first DC conversion module, The charging device is characterized in that.

2. When the control module alternately operates the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit, it controls the first half-bridge LLC circuit unit to operate, records the first operation time of the first half-bridge LLC circuit unit, and when the first operation time reaches the time threshold value, switches to operate the second half-bridge LLC circuit unit, and records the second operation time of the second half-bridge LLC circuit unit, and when the second operation time reaches the time threshold value, switches to operate the first half-bridge LLC circuit unit, and the charging device according to claim 1, characterized in that the process is executed cyclically.

3. The control module further controls the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate simultaneously when the total output current is equal to or greater than the current threshold value, and the charging device according to claim 1 or 2 is characterized in that.

4. When the control module controls the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate simultaneously, the switch transistors of the first half-bridge LLC circuit unit and the switch transistors of the second half-bridge LLC circuit unit are interleaved and controlled with a difference in a predetermined phase angle, and the charging device according to any one of claims 1 to 3 is characterized in that.

5. The second half-bridge LLC circuit unit is A fifth switch transistor and a sixth switch transistor, wherein the fifth switch transistor has a first end connected to the first end of the power battery, a second end connected to the first end of the sixth switch transistor, and a control end connected to the control module; the sixth switch transistor has a second end connected to the second end of the power battery and a control end connected to the control module, and there is a second node between the second end of the fifth switch transistor and the first end of the sixth switch transistor. A second capacitor and a second inductor, wherein the second capacitor has a first end connected to the second node and a second end connected to the first end of the second inductor. A second transformer including a second primary coil, a third secondary coil, and a fourth secondary coil, wherein the second primary coil has a first end connected to the second end of the second inductor and a second end connected to the second end of the first transformer, the second end of the second switch transistor, and the second end of the sixth switch transistor respectively; the second end of the third secondary coil and the first end of the fourth secondary coil are connected to form a second common end, and the second common end is connected to the second end of the storage battery. A seventh switch transistor and an eighth switch transistor, wherein the seventh switch transistor has a first end connected to the first end of the third secondary coil, a second end connected to the first end of the storage battery, and a control end connected to the control module; the eighth switch transistor has a first end connected to the second end of the fourth secondary coil, a second end connected to the second end of the seventh switch transistor and the first end of the storage battery respectively, and a control end connected to the control module. The charging device according to claim 1, characterized by comprising the seventh switch transistor and the eighth switch transistor.

6. The first DC conversion module further includes a filtering unit, wherein a first end of the filtering unit is connected to the first end of the storage battery and a second end of the filtering unit is connected to the second end of the storage battery. The charging device according to claim 1, characterized by this.

7. The charging device is A filtering module with a first end connected to an AC power source, Perform power factor improvement on the input AC current, output a DC current signal after power factor improvement, and at least include a three-phase bridge arm in which each phase bridge arm is connected to the second end of the filtering module by a power inductor, a PFC circuit module; The charging device according to claim 1, further comprising a second DC conversion module, wherein an input end thereof is connected to an output end of the PFC circuit module, and an output end thereof is connected to the power battery.

8. A storage battery; A power battery; A vehicle, comprising the storage battery and the charging device according to any one of claims 1 to 7, which are respectively connected to the storage battery and the power battery.

9. A method for controlling the charging of a charging device, wherein the charging device converts a DC current signal output from a power battery into a DC current signal required by a storage battery, and includes a first DC conversion module including a first half-bridge LLC circuit unit and a second half-bridge LLC circuit unit installed in parallel. The first half-bridge LLC circuit unit includes: A first switch transistor and a second switch transistor, wherein the first switch transistor has a first end connected to a first end of the power battery, a second end connected to a first end of the second switch transistor, and a control end connected to the control module; the second switch transistor has a second end connected to a second end of the power battery and a control end connected to the control module; and there is a first node between the second end of the first switch transistor and the first end of the second switch transistor. The first switch transistor and the second switch transistor; A first capacitor and a first inductor, wherein the first capacitor has a first end connected to the first node and a second end connected to a first end of the first inductor. The first capacitor and the first inductor; A first transformer including a first primary coil, a first secondary coil, and a second secondary coil, wherein the first primary coil has a first end connected to a second end of the first inductor and a second end connected to a second end of the second switch transistor; the second ends of the first secondary coil and the first ends of the second secondary coil are connected to form a first common end, and the first common end is connected to a second end of the storage battery. The first transformer; A third switch transistor and a fourth switch transistor, wherein the first end of the third switch transistor is connected to the first end of the first secondary coil, the second end is connected to the first end of the storage battery, and the control end is connected to the control module; the first end of the fourth switch transistor is connected to the second end of the second secondary coil, the second end is connected to the second end of the third switch transistor and the first end of the storage battery, and the control end is connected to the control module, including a third switch transistor and a fourth switch transistor, The method includes: obtaining the total output current of the first DC conversion module; determining whether the total output current is less than a current threshold; when the total output current is less than the current threshold, controlling the first half-bridge LLC circuit unit and the second half-bridge LLC circuit unit to operate alternately; The current threshold is half of the maximum value of the total output current of the first DC conversion module, characterized in that it is a method for controlling the charging of a charging device.

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