Power battery charging device, battery system and new energy vehicle with same

Abstract

The utility model discloses a kind of power battery charging device, battery system and new energy vehicle with it, charging device includes sequentially connected front-stage rectifier circuit, inverter circuit, resonant cavity circuit, rear-stage rectifier circuit, rear-stage bus circuit, rear-stage relay circuit;Front-stage rectifier circuit is rectified into direct current by external alternating current and is output on front-stage bus;Inverter circuit is rectified into alternating current by direct current on front-stage bus, and is resonant amplification, isolation by resonant cavity circuit;Rear-stage bus voltage detection circuit is configured to detect the voltage of rear-stage bus, and front-stage controller circuit adjusts the control of power switch to inverter circuit according to the detection result of rear-stage bus voltage;Rear-stage rectifier circuit is rectified into direct current by alternating current that has passed through resonant cavity circuit, and is output on rear-stage bus, and rear-stage relay has two controlled pins, one of which is accessed to rear-stage bus, and the other is accessed to output bus, and the control end of relay is connected with rear-stage controller circuit.

Description

Technical Field

[0001] This utility model relates to the field of power battery charging, and in particular to a power battery charging device, a battery system, and a new energy vehicle having the same. Background Technology

[0002] With the global energy structure adjustment and increasingly stringent environmental policies, the new energy vehicle industry is developing rapidly. As the core energy storage unit, the safety and efficiency of the charging system for power batteries have become a technological focus. Power battery chargers, as key equipment connecting the power grid and battery packs, need to achieve efficient energy conversion and reliable on / off control under high voltage and high current conditions. Their performance and reliability directly affect the charging efficiency, safety, and user experience of the entire vehicle. Currently, new energy vehicle power battery chargers are developing towards high power density, high efficiency, intelligence, and high safety to meet the needs of fast charging, multi-scenario applications, and complex power grid environments. In this process, relays, as the core switching component of the charger, directly affect the stability, response speed, and electrical life of the charging system.

[0003] To shorten charging time, chargers need to support high power output (such as 350kW and above), which places higher demands on the voltage withstand capability, heat dissipation, and control precision of power devices (such as IGBTs and SiC MOSFETs). In current charging modes, overshoot techniques such as overvoltage overshoot or overcurrent overshoot are commonly used to quickly reach the specified voltage or current value. However, this overshoot technique greatly reduces the lifespan of downstream relays.

[0004] The above background information is provided only to aid in understanding the concept and technical solution of this application. It does not necessarily belong to the prior art of this application, nor does it necessarily provide technical guidance. In the absence of clear evidence that the above information was disclosed before the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Utility Model Content

[0005] The purpose of this invention is to provide a power battery charging device that uses a multi-segment voltage control method to output voltage more gently, thereby reducing the impact of its output.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0007] A power battery charging device includes a front-end circuit, a back-end circuit, and a control and detection auxiliary circuit, wherein:

[0008] The front-end circuit includes a front-end rectifier circuit, a DC-AC inverter circuit, and an LLC resonant cavity circuit.

[0009] The subsequent circuit includes a subsequent rectifier circuit, a subsequent bus circuit, and a subsequent relay circuit;

[0010] The control and detection auxiliary circuit includes a front-end controller circuit, a back-end bus voltage detection circuit, and a back-end controller circuit.

[0011] The pre-stage rectifier circuit, DC-AC inverter circuit, LLC resonant cavity circuit, post-stage rectifier circuit, post-stage bus circuit, and post-stage relay circuit are connected in sequence. The pre-stage rectifier circuit rectifies the external AC power into DC power and outputs it on the pre-stage bus.

[0012] The DC-AC inverter circuit converts the DC power on the front bus into AC power, which is then amplified and isolated by the LLC resonant cavity circuit. The rear bus voltage detection circuit is configured to detect the voltage of the rear bus, and the front controller circuit adjusts the control of the power switch of the DC-AC inverter circuit according to the detection result of the rear bus voltage.

[0013] The subsequent rectifier circuit rectifies the AC power from the LLC resonant cavity circuit into DC power and outputs it to the subsequent bus of the subsequent bus circuit. The relay of the subsequent relay circuit has two controlled pins, one of which is connected to the subsequent bus and the other is connected to the output bus. The control terminal of the relay is connected to the subsequent controller circuit.

[0014] Furthermore, following any or a combination of the aforementioned technical solutions, the downstream bus voltage detection circuit includes multiple voltage divider resistors, a comparator, and an optocoupler. The voltage across the voltage divider resistors and a preset reference voltage are connected to the input terminal of the comparator, and the output terminal of the comparator is connected to the input side of the optocoupler.

[0015] The output side of the optocoupler is connected to the front-end controller circuit.

[0016] Furthermore, based on any or a combination of the aforementioned technical solutions, the downstream controller circuit is configured to set or adjust the reference voltage connected to the comparator input terminal in the downstream bus voltage detection circuit, or to adjust or change the resistance value of the voltage divider resistor in the downstream bus voltage detection circuit.

[0017] Furthermore, following any or a combination of the aforementioned technical solutions, the control and detection auxiliary circuit also includes a downstream auxiliary power supply circuit, which is configured to perform a BUCK step-down chopping transformation on the downstream bus through a BUCK step-down circuit composed of an inductor and a MOSFET, so as to output a stepped-down auxiliary power supply DC voltage to the downstream controller circuit.

[0018] Furthermore, based on any or a combination of the aforementioned technical solutions, the front-end rectifier circuit includes a full-bridge rectifier composed of four power diodes.

[0019] Furthermore, following any one or a combination of the aforementioned technical solutions, the DC-AC inverter circuit includes two bridge arms composed of two MOSFETs, and the conduction and turn-off of the MOSFETs are controlled by the front-end controller circuit.

[0020] Furthermore, based on any or a combination of the aforementioned technical solutions, the LLC resonant cavity circuit includes a resonant inductor and a resonant capacitor, wherein the resonant inductor, the primary winding of the transformer, and the resonant capacitor are connected in sequence.

[0021] Furthermore, following any one or a combination of the aforementioned technical solutions, the subsequent rectifier circuit is composed of a half-bridge rectifier circuit made of diodes and an RCD energy absorption circuit.

[0022] According to another aspect of the present invention, the present invention provides a battery system including a battery and a power battery charging device as described above.

[0023] According to another aspect of the present invention, the present invention provides a new energy vehicle, wherein the power system of the vehicle includes the battery system described above.

[0024] The beneficial effects of the technical solution provided by this utility model are as follows:

[0025] a. The independent downstream bus voltage detection circuit does not need to wait for the signal processing of the downstream controller circuit. It can quickly respond and feed back the current downstream bus information value, and send the feedback information value to the upstream controller through the optocoupler.

[0026] b. The downstream controller circuit can control the downstream bus voltage detection circuit, change the bus voltage limit, and thus change the voltage value on the downstream bus to meet the target value required by the system. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A schematic diagram of the circuit architecture of a charging device provided for an exemplary embodiment of the present invention;

[0029] Figure 2 A schematic diagram of the structure of a downstream relay circuit provided for an exemplary embodiment of the present invention;

[0030] Figure 3 A schematic diagram of the structure of a downstream bus voltage detection circuit provided for an exemplary embodiment of the present invention;

[0031] Figure 4 A schematic diagram of the chip structure of a front-end controller circuit provided for an exemplary embodiment of the present invention;

[0032] Figure 5 A schematic diagram of the structure of a downstream auxiliary power supply circuit provided for an exemplary embodiment of the present invention;

[0033] Figure 6 A schematic diagram of the structure of a front-end rectifier circuit provided for an exemplary embodiment of the present invention;

[0034] Figure 7 A schematic diagram of the structure of a DC-AC inverter circuit provided as an exemplary embodiment of the present invention;

[0035] Figure 8 A schematic diagram of the LLC resonant cavity circuit provided as an exemplary embodiment of the present invention;

[0036] Figure 9 A schematic diagram of the structure of a subsequent rectifier circuit provided for an exemplary embodiment of the present invention;

[0037] Figure 10 A schematic diagram of the chip structure of a post-stage controller circuit provided for an exemplary embodiment of the present invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the solutions of this application, the technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection claimed by the present utility model.

[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this utility model are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the utility model described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, apparatus, product, or device that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0040] In the high-voltage circuit of the charger, the relay, as the core switching element, undertakes functions such as charging on / off, pre-charge protection, and fault isolation. The relay is an important component of the power battery charger, and extending its service life enhances the service life of the power battery charger.

[0041] In one embodiment of this utility model, a power battery charging device is provided, including a front-end circuit, a back-end circuit, and a control and detection auxiliary circuit, wherein:

[0042] The front-end circuit includes a front-end rectifier circuit, a DC-AC inverter circuit, and an LLC resonant cavity circuit.

[0043] The subsequent circuit includes a subsequent rectifier circuit, a subsequent bus circuit, and a subsequent relay circuit;

[0044] The control and detection auxiliary circuit includes a front-end controller circuit, a back-end bus voltage detection circuit, and a back-end controller circuit.

[0045] like Figure 1 As shown, the front-stage rectifier circuit, DC-AC inverter circuit, LLC resonant cavity circuit, rear-stage rectifier circuit, rear-stage bus circuit, and rear-stage relay circuit are connected in sequence. The front-stage rectifier circuit rectifies the external AC power into DC power and outputs it on the front-stage bus.

[0046] The DC-AC inverter circuit converts the DC power on the front bus into AC power, which is then amplified and isolated by the LLC resonant cavity circuit. The rear bus voltage detection circuit is configured to detect the voltage of the rear bus, and the front controller circuit adjusts the control of the power switch of the DC-AC inverter circuit according to the detection result of the rear bus voltage.

[0047] The subsequent rectifier circuit rectifies the AC power from the LLC resonant cavity circuit into DC power and outputs it to the subsequent bus of the subsequent bus circuit, such as... Figure 2As shown, the relay in the downstream relay circuit has two controlled pins, one connected to the downstream bus and the other to the output bus. The control terminal of the relay is connected to the downstream controller circuit. In this embodiment, the downstream controller circuit uses an N32G430 chip, the structure of which is shown below. Figure 10 As shown. The downstream controller circuit monitors the voltage on the downstream bus and the current at the output terminal in real time. The setting logic algorithm inside the N32G430 chip can automatically control its signal feedback value to the upstream controller to adjust the voltage and current values ​​on the downstream bus. When it detects a small voltage value on the bus (enough to provide sufficient energy for the relay to engage; generally, when the MCU is working, the relay engagement energy has met the requirements), it sends a signal to the relay control circuit to engage the relay, reducing the impact of large voltage on the relay. The MCU can also control an independent downstream bus voltage detection circuit, changing its individual response value, thereby changing the voltage of the output bus. In this invention, the independent downstream bus voltage detection circuit does not need to wait for the signal processing of the downstream controller circuit; it can quickly respond and feedback the current downstream bus information value, sending the feedback information value to the upstream controller via an optocoupler. Using the independent downstream bus voltage detection circuit, the response time can be within 500µs, completing the bus voltage detection, feedback, and information processing.

[0048] This utility model's charging device employs a multi-stage voltage control method, with a front-end and a rear-end stage. The front-end stage provides a fast response, while the rear-end stage outputs a more gentle voltage, reducing output surges, extending the lifespan of the power battery charger, and effectively improving the problem of excessively high output voltage during startup, ensuring the power battery charger operates at its optimal state. The power battery charger's output voltage can be adjusted for two-stage startup and a gentle, slow startup. The startup rate and time of the output voltage, as well as the rate and magnitude of the charging current rise, can be modified according to the battery's BMS voltage request value, allowing for adjustment based on actual conditions.

[0049] like Figure 3 As shown, the downstream bus voltage detection circuit includes multiple voltage divider resistors, a comparator, and an optocoupler. The voltage across the voltage divider resistors and a preset reference voltage are connected to the input of the comparator, and the output of the comparator is connected to the input of the optocoupler. The downstream bus voltage detection circuit detects the voltage on the downstream output bus through the voltage divider resistors, and the voltage across the voltage divider resistors represents the current voltage value on the bus.

[0050] The voltage across the voltage divider resistor is compared with a reference voltage (e.g., 2.5V):

[0051] When the voltage differs from the reference voltage, the voltage signal is transmitted to the optocoupler, which then transmits a signal to the front-end controller circuit. This causes the controller to control the MOSFETs in the current DC-AC inverter circuit, changing the on / off time and time interval. Consequently, the voltage on the downstream bus changes. When the voltage is the same as the reference voltage, no voltage signal is transmitted to the optocoupler. If the bus voltage limit of the downstream bus voltage detection circuit is too low or too high, the downstream controller circuit can control the detection circuit. This includes adjusting or changing the resistance value of the voltage divider resistor in the downstream bus voltage detection circuit, or setting or adjusting the reference voltage connected to the comparator input in the downstream bus voltage detection circuit to change the bus voltage limit. This, in turn, changes the voltage value on the downstream bus to meet the target value required by the system.

[0052] The output side of the optocoupler is connected to the front-end controller circuit. In this embodiment, the front-end controller circuit uses an NCP1399 chip, the structure of which is as follows: Figure 4 As shown.

[0053] like Figure 1 As shown, the control and detection auxiliary circuit also includes a downstream auxiliary power supply circuit, which is configured to perform a buck-step-down chopping transformation on the downstream bus through a buck circuit composed of an inductor and a MOSFET, so as to output a stable auxiliary power supply DC voltage (e.g., 14V) to the downstream controller circuit. The circuit diagram of the downstream auxiliary power supply circuit is shown below. Figure 5 As shown.

[0054] like Figure 6 As shown, the front-end rectifier circuit includes a full-bridge rectifier composed of four power diodes. The AC power is rectified by the full-bridge uncontrolled rectifier to complete the AC-DC conversion. After the "peak shaving and valley filling" filtering by the capacitor, the AC power is successfully rectified into DC power and output on the front-end bus.

[0055] like Figure 7 As shown, the DC-AC inverter circuit includes two bridge arms composed of two MOSFETs. The switching on and off of the MOSFETs is controlled by the pre-stage controller circuit: the drive signal output by the pre-stage controller controls the switching on and off of the two MOSFETs, thereby converting the DC power on the bus into AC power. The aforementioned pre-stage controller circuit is started by the high voltage of the pre-stage bus and drives the two MOSFET bridge arms of the DC-AC inverter circuit through calculations in the internal circuitry of the chip (NCP1399 chip) to control their switching on or off.

[0056] like Figure 8As shown, the LLC resonant cavity circuit includes a resonant inductor and a resonant capacitor. The resonant inductor, the primary coil of the transformer, and the resonant capacitor are connected in sequence. The AC power after DC-AC inversion is amplified and isolated by resonance to output a brand new AC power.

[0057] like Figure 9 As shown, the subsequent rectifier circuit consists of a half-bridge rectifier circuit composed of diodes and an RCD energy absorption circuit, which rectifies the AC power into DC power, filters it through an electrolytic capacitor, and outputs it to the subsequent bus.

[0058] In one embodiment of the present invention, a battery system is provided, including a battery and a power battery charging device as described above; the present invention also provides a new energy vehicle, wherein the power system of the vehicle includes the battery system as described above.

[0059] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0060] The above description is only a specific embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A power battery charging device, characterized in that, It includes pre-amplifier circuits, power-up circuits, and control and detection auxiliary circuits, among which: The front-end circuit includes a front-end rectifier circuit, a DC-AC inverter circuit, and an LLC resonant cavity circuit. The subsequent circuit includes a subsequent rectifier circuit, a subsequent bus circuit, and a subsequent relay circuit; The control and detection auxiliary circuit includes a front-end controller circuit, a back-end bus voltage detection circuit, and a back-end controller circuit. The pre-stage rectifier circuit, DC-AC inverter circuit, LLC resonant cavity circuit, post-stage rectifier circuit, post-stage bus circuit, and post-stage relay circuit are connected in sequence. The pre-stage rectifier circuit rectifies the external AC power into DC power and outputs it on the pre-stage bus. The DC-AC inverter circuit converts the DC power on the front bus into AC power, which is then amplified and isolated by the LLC resonant cavity circuit. The rear bus voltage detection circuit is configured to detect the voltage of the rear bus, and the front controller circuit adjusts the control of the power switch of the DC-AC inverter circuit according to the detection result of the rear bus voltage. The subsequent rectifier circuit rectifies the AC power from the LLC resonant cavity circuit into DC power and outputs it to the subsequent bus of the subsequent bus circuit. The relay of the subsequent relay circuit has two controlled pins, one of which is connected to the subsequent bus and the other is connected to the output bus. The control terminal of the relay is connected to the subsequent controller circuit.

2. The power battery charging device according to claim 1, characterized in that, The downstream bus voltage detection circuit includes multiple voltage divider resistors, a comparator, and an optocoupler. The voltage across the voltage divider resistors and a preset reference voltage are connected to the input terminal of the comparator, and the output terminal of the comparator is connected to the input side of the optocoupler. The output side of the optocoupler is connected to the front-end controller circuit.

3. The power battery charging device according to claim 2, characterized in that, The downstream controller circuit is configured to set or adjust the reference voltage connected to the comparator input in the downstream bus voltage detection circuit, or to adjust or change the resistance value of the voltage divider resistor in the downstream bus voltage detection circuit.

4. The power battery charging device according to claim 1, characterized in that, The control and detection auxiliary circuit also includes a downstream auxiliary power supply circuit, which is configured to perform a BUCK step-down chopping transformation on the downstream bus through a BUCK step-down circuit composed of an inductor and a MOSFET, so as to output a stepped-down auxiliary power supply DC voltage to the downstream controller circuit.

5. The power battery charging device according to claim 1, characterized in that, The front-end rectifier circuit includes a full-bridge rectifier consisting of four power diodes.

6. The power battery charging device according to claim 1, characterized in that, The DC-AC inverter circuit includes two bridge arms composed of two MOSFETs, and the switching on and off of the MOSFETs is controlled by the front-end controller circuit.

7. The power battery charging device according to claim 1, characterized in that, The LLC resonant cavity circuit includes a resonant inductor and a resonant capacitor, and the resonant inductor, the primary coil of the transformer, and the resonant capacitor are connected in sequence.

8. The power battery charging device according to claim 1, characterized in that, The subsequent rectifier circuit consists of a half-bridge rectifier circuit composed of diodes and an RCD energy absorption circuit.

9. A battery system, characterized in that, Includes a battery and a power battery charging device as described in any one of claims 1 to 8.

10. A new energy transportation vehicle, characterized in that, The power system of the vehicle includes the battery system as described in claim 9.

Images