A multifunctional device applied to a high-pressure system of a vehicle and the vehicle

Abstract

The application relates to the new energy field, in particular to a multifunctional device and a vehicle. The multifunctional device comprises a power supply, an inverter, a motor and a multifunctional device. The power supply is used for supplying power to the inverter, the motor and the multifunctional device. Under the action of the multifunctional device, the multifunctional device can realize multiple functions. The multifunctional device comprises multiple switches, multiple switch tubes and a second controller. Under the cooperation of the multiple switches, the multiple switch tubes and the second controller, the multifunctional device can realize multiple different functions. Therefore, the multifunctional device can solve the technical problem that the high-voltage system in the prior art can only realize the function of driving the motor through the battery and the electric control to drive the vehicle to move, the function is very single, multiple different functions can be realized, and the application requirement of different scenes can be adapted.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of circuit, in particular to a multifunctional device applied to a high-voltage system of a vehicle and the vehicle. BACKGROUND

[0002] In the field of new energy vehicles, as shown in the figure, the traditional high-voltage system is composed of a battery, a motor and an electric control. Among them, the battery usually refers to a high-voltage power battery pack, which is the core component of storing high-voltage electric energy. The motor, full name driving motor, is the core component of converting high-voltage electric energy into mechanical energy. The electric control, full name motor controller (MCU), is the bridge connecting the battery and the motor, responsible for analyzing instructions and adjusting energy. At present, the high-voltage system can only drive the motor through the battery and the electric control, so as to push the vehicle to move, which is a very single function. Figure 1 SUMMARY

[0003] The present application provides a multifunctional device applied to a high-voltage system of a vehicle, which can realize multiple functions and adapt to different scene use requirements.

[0004] In a first aspect, a multifunctional device applied to a high-voltage system of a vehicle is provided, comprising:

[0005] a power supply comprising a first switch, a battery and a second switch connected in series, a first end of the first switch being connected to a first end of the battery, a second end of the battery being connected to a first end of the second switch;

[0006] an inverter comprising a first controller, a first branch, a second branch, a third branch and a fourth branch arranged side by side, wherein the first branch comprises a first capacitor, the second branch comprises a first switch tube and a second switch tube connected in series, the third branch comprises a third switch tube and a fourth switch tube connected in series, the fourth branch comprises a fifth switch tube and a sixth switch tube connected in series, control ends of the first switch tube to the sixth switch tube are connected with the first controller respectively, and the inverter and the power supply are connected in parallel;

[0007] a motor comprising a first coil, a second coil and a third coil, a first end of the first coil being connected to a common end of the first switch tube and the second switch tube, a first end of the second coil being connected to a common end of the third switch tube and the fourth switch tube, and a first end of the third coil being connected to a common end of the fifth switch tube and the sixth switch tube, and a second end of the first coil, a second end of the second coil and a second end of the third coil being connected;

[0008] ​The multifunctional device comprises a third switch, a fourth switch, a fifth switch, a sixth switch, a fourth coil, a seventh switch tube, an eighth switch tube, a second capacitor, and a second controller. The first end of the third switch is connected to the second end of the first switch. The second end of the third switch is connected to the input end of the seventh switch tube. The first end of the fourth switch is connected to the first end of the third switch. The second end of the fourth switch is connected to the first end of the fourth coil. The first end of the fifth switch is connected to the common end of the first coil, the second coil and the third coil. The second end of the fifth switch is connected to the first end of the fourth coil. The first end of the sixth switch is connected to the second end of the second switch. The second end of the sixth switch is connected to the output end of the eighth switch tube. The second end of the fourth coil is connected to the common end between the seventh switch tube and the eighth switch tube. The output end of the seventh switch tube is connected to the input end of the eighth switch tube. The control ends of the seventh switch tube and the eighth switch tube are respectively connected to the control port of the second controller. The second end of the third switch is connected to the first end of the second capacitor. The second end of the sixth switch is connected to the second end of the second capacitor. The first switch tube to the eighth switch tube are respectively connected with diodes in parallel.

[0009] In the high-voltage power-on mode,

[0010] The first switch is closed. The second switch is closed. The third switch is opened. The fourth switch is opened. The fifth switch is closed. The sixth switch is closed.

[0011] The first controller is configured to input a first pulse width modulation (PWM) signal to at least one of the first switch tube, the third switch tube and the fifth switch tube. The second controller is configured to input the first PWM signal to the eighth switch tube.

[0012] In the above scheme, the system is in a buck state, and the second capacitor is slowly charged to be close to the voltage of the battery, so as to avoid that the voltage difference between the two sides of the switch is too large, a large inrush current is generated at the moment of closing, and the contactor is stuck.

[0013] In some possible designs, when the system is switched from the high-voltage power-on mode to the driving mode,

[0014] The third switch is closed. The fifth switch is opened. The sixth switch is closed.

[0015] The first controller is configured to stop inputting the first PWM signal to at least one of the first switch tube, the third switch tube and the fifth switch tube. The second controller is configured to stop inputting the first PWM signal to the eighth switch tube.

[0016] In the above scheme, the amplitude of the inverter bus voltage fluctuation is well inhibited, especially during the vehicle rapid acceleration or deceleration driving, the second capacitor well absorbs the power fluctuation on the DC bus, so that the bus voltage in the inverter is more stable, which helps to improve the stability of the inverter control and maintain stable output performance; In addition, the vehicle driving has randomness, so the demand power fluctuation can be very large, the second capacitor can effectively absorb the power fluctuation of the motor, thereby reducing the fluctuation amplitude of the battery output power, which helps to prolong the service life of the battery; When the vehicle has a serious fault during high-speed operation, the inverter stops current output immediately for self-protection, and the back electromotive force of the motor suddenly rises under high speed. At this time, the second capacitor will quickly absorb the impact current from the motor, thereby avoiding the serious impact of the sudden increase of the back electromotive force of the motor on the inverter and the high-voltage system of the vehicle, and even causing damage.

[0017] In some possible designs, in the conversion from the high-voltage power-on mode to the ordinary charging mode,

[0018] The third switch is closed, the fifth switch is opened, and the sixth switch is closed,

[0019] The first controller is configured to stop inputting the first PWM signal to at least one of the first switch tube, the third switch tube, and the fifth switch tube, and the second controller is configured to stop inputting the first PWM signal to the eighth switch tube.

[0020] In the above scheme, the second capacitor can absorb the power fluctuation from the charging pile, so that the charging power of the vehicle is more stable, the battery is better protected, and the power fluctuation caused by the continuous adjustment of the output of the charging pile is effectively reduced; In the charging process, the vehicle is urgently or accidentally cut off the related contactor (such as the first switch and the second switch) due to some reason, but the charging pile still maintains the output. At this time, the second capacitor will effectively absorb the power from the charging pile, leaving enough fault response time for the charging pile, so as to avoid damage to the high-voltage system of the vehicle or the charging pile.

[0021] In some possible designs, in the conversion from the high-voltage power-on mode to the step-up charging mode,

[0022] The first controller is configured to input the second PWM signal to at least one of the second switch tube, the fourth switch tube, and the sixth switch tube; and the second controller is configured to input the second PWM signal to the seventh switch tube.

[0023] In the case where the voltage of the second capacitor is approximately equal to the rated working voltage of the charging pile, the first controller is configured to stop inputting the second PWM signal to at least one of the second switch tube, the fourth switch tube, and the sixth switch tube; and the second controller is configured to stop inputting the second PWM signal to the seventh switch tube.

[0024] In the case where the BMS controller sends a charging request to the charging pile, the first controller is configured to input a third PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to input the third PWM signal to the seventh switch.

[0025] In the above scheme, since the voltage of the battery is relatively high and the voltage of the charging pile is relatively low, the second capacitor can be charged to the vicinity of the rated working voltage of the charging pile first, and then the charging request can be sent to the charging pile. Then, the battery changes from the discharging mode to the charging mode, and the first controller is configured to input a third PWM signal to at least one of the second switch, the fourth switch and the sixth switch. At this time, the system is in a boost mode, and the voltage can be raised to charge the battery.

[0026] In some possible designs, in the case where the BMS controller sends a stop charging request to the charging pile, the first controller is configured to stop inputting a third PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to stop inputting the third PWM signal to the seventh switch.

[0027] The first controller is configured to input a first PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to input the first PWM signal to the eighth switch.

[0028] The third switch is closed, and the fifth switch is opened.

[0029] In the above scheme, after the charging is completed, the system can be converted from the boost mode to a buck mode, so that the second capacitor is re-parallel connected to the inverter.

[0030] In some possible designs, in the conversion from the high-voltage power-on mode to the parking heating mode,

[0031] The first controller is configured to stop inputting a first PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to stop inputting the first PWM signal to the eighth switch.

[0032] The first controller is configured to input a fourth PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to input the fourth PWM signal to the seventh switch. The eighth switch is closed.

[0033] In the case that the voltage of the second capacitor is less than or equal to the lower limit value of the voltage, the first controller is configured to stop inputting the fourth PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to stop inputting the fourth PWM signal to the seventh switch;

[0034] The first controller is configured to input the fifth PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to input the fifth PWM signal to the eighth switch;

[0035] In the case that the voltage of the second capacitor is greater than or equal to the upper limit value of the voltage, the above steps are repeated until the first controller receives a stop heating command.

[0036] In the above scheme, during the parking process, the current in the battery also flows alternately in positive and negative directions through repeated charging and discharging of the second capacitor, and the battery itself has a resistance-capacitance characteristic, an equivalent internal resistance, and a reduced battery temperature. The equivalent internal resistance will increase, and the current flowing through the resistance will generate corresponding heat. The heat generated in this way directly acts on the inside of the battery, so the heating efficiency is very high.

[0037] In some possible designs, in the case of switching from the high-voltage power-on mode to the driving heating mode,

[0038] The fourth switch is closed, and the fifth switch is opened,

[0039] The first controller is configured to stop inputting the first PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to stop inputting the first PWM signal to the eighth switch;

[0040] The second controller is configured to input the fourth PWM signal to the seventh switch;

[0041] The second controller is configured to control the eighth switch to be closed;

[0042] In the case that the voltage of the second capacitor is less than or equal to the lower limit value of the voltage, the second controller is configured to stop inputting the fourth PWM signal to the seventh switch;

[0043] The second controller is configured to input the fifth PWM signal to the eighth switch;

[0044] In the case that the voltage of the second capacitor is greater than or equal to the upper limit value of the voltage, the above steps are repeated until the first controller receives a stop heating command.

[0045] In the above scheme, during the driving process, the current in the battery will also flow alternately in positive and negative directions by repeatedly charging and discharging the second capacitor, and the battery itself has a resistance-capacitance characteristic, has an equivalent internal resistance, and the equivalent internal resistance will increase as the battery temperature decreases. The current flowing through the resistance generates corresponding heat, and the heat generated by this method directly acts on the inside of the battery, so the heating efficiency is very high.

[0046] In some possible designs, when switching from the high-voltage power-on mode to the high-voltage power-off mode,

[0047] The second controller is configured to input a sixth PWM signal to the seventh switch tube;

[0048] The first controller is configured to input a sixth PWM signal to at least one of the second switch tube, the fourth switch tube, and the sixth switch tube;

[0049] When the voltage of the second capacitor is less than or equal to the safe voltage, the second controller is configured to stop inputting the sixth PWM signal to the seventh switch tube, and the first controller is configured to stop inputting the sixth PWM signal to at least one of the second switch tube, the fourth switch tube, and the sixth switch tube;

[0050] The first switch, the second switch, the third switch, the fourth switch, the fifth switch, and the sixth switch are all disconnected.

[0051] In the above scheme, in the high-voltage power-off mode, the excess power in the second capacitor can be charged back into the battery through the boost mode to save power. After transferring the power of the second capacitor back to the battery, all the switches are disconnected, and then the inverter actively discharges to release the power in the first capacitor through the motor, so that the voltage of the first capacitor is reduced to below the target safe voltage.

[0052] In a second aspect, a vehicle is provided, which comprises the multifunctional device for a high-voltage system of a vehicle according to any one of the first aspect.

[0053] In summary, the multifunctional device and the vehicle provided by the present application can solve the problem that the high-voltage system in the prior art can only drive the motor through the battery and the electric control, thereby promoting the movement of the vehicle, which is a very single function. The multifunctional device and the vehicle provided by the present application can realize multiple different functions and adapt to different application requirements in different scenarios. BRIEF DESCRIPTION OF DRAWINGS

[0054] Figure 1 is a structural schematic diagram of a power system in the prior art;

[0055] Figure 2is a structural schematic diagram of a multifunctional device applied to a vehicle high-voltage system provided by the present application.

[0056] Figure 3 is Figure 2 is a current direction diagram of the multifunctional device applied to the vehicle high-voltage system in a high-voltage power-on mode.

[0057] Figure 4 is Figure 2 is a current direction diagram of the multifunctional device applied to the vehicle high-voltage system in a boost charging mode.

[0058] Figure 5 is Figure 2 is a current direction diagram of the multifunctional device applied to the vehicle high-voltage system in a boost mode in a driving heating mode.

[0059] Figure 6 is Figure 2 is a current direction diagram of the multifunctional device applied to the vehicle high-voltage system in a buck mode in a driving heating mode. DETAILED DESCRIPTION

[0060] Referring to Figure 2 , Figure 2 is a structural schematic diagram of a multifunctional device applied to a vehicle high-voltage system provided by the present application. Figure 2 As shown in the figure, the multifunctional device applied to the vehicle high-voltage system of the present application comprises:

[0061] The power supply 110 comprises a first switch K1, a battery B and a second switch K2 connected in series. The first end of the first switch K1 is connected to the first end of the battery, and the second end of the battery B is connected to the first end of the second switch K2.

[0062] The inverter 120 comprises a first controller S1 and a first branch, a second branch, a third branch and a fourth branch arranged in parallel.

[0063] The first branch comprises a first capacitor C1. That is, the first end of the first capacitor C1 is connected to the second end of the first switch K1, and the second end of the first capacitor C1 is connected to the second end of the second switch K2.

[0064] The second branch comprises a first switch tube Q1 and a second switch tube Q2 connected in series. That is, the input end of the first switch tube Q1 is connected to the second end of the first switch K1, the output end of the first switch tube Q1 is connected to the input end of the second switch tube Q2, and the output end of the second switch tube Q2 is connected to the second end of the second switch K2.

[0065] The third branch includes a third switch tube Q3 and a fourth switch tube Q4 connected in series. That is, the input end of the third switch tube Q3 is connected to the second end of the first switch K1, the output end of the third switch tube Q3 is connected to the input end of the fourth switch tube Q4, and the output end of the fourth switch tube Q4 is connected to the second end of the second switch K2.

[0066] The fourth branch includes a fifth switch tube Q5 and a sixth switch tube Q6 connected in series. That is, the input end of the fifth switch tube Q5 is connected to the second end of the first switch K1, the output end of the fifth switch tube Q5 is connected to the input end of the sixth switch tube Q6, and the output end of the sixth switch tube Q6 is connected to the second end of the second switch K2.

[0067] The control ends of the first switch tube Q1 to the sixth switch tube Q6 are respectively connected to a control port of the first controller S1.

[0068] The motor 130 includes a first coil L1, a second coil L2, and a third coil L3. Among them,

[0069] The first end of the first coil L1 is connected to the common end of the first switch tube Q1 and the second switch tube Q2.

[0070] The first end of the second coil L2 is connected to the common end of the third switch tube Q3 and the fourth switch tube Q4.

[0071] The first end of the third coil L3 is connected to the common end of the fifth switch tube Q5 and the sixth switch tube Q6.

[0072] The second end of the first coil L1, the second end of the second coil L2, and the second end of the third coil L3 are connected.

[0073] The multifunctional device 140 includes a third switch K3, a fourth switch K4, a fifth switch K5, a sixth switch K6, a fourth coil L4, a seventh switch tube Q7, an eighth switch tube Q8, a second capacitor C2, and a second controller S2. The second capacitor can be a super capacitor. The super capacitor is a new type of energy storage device between traditional capacitors (such as ceramic capacitors and aluminum electrolytic capacitors) and power batteries. It not only retains the characteristics of fast charging and discharging of traditional capacitors, but also has a storage capacity far exceeding that of traditional capacitors. The core advantages are high instantaneous power density, long cycle life, and fast charging and discharging speed, which can complete energy absorption and release in milliseconds. The capacitance value of the second capacitor is greater than that of the first capacitor. For example, the capacitance value of the second capacitor is much greater than that of the first capacitor. For example, the capacitance value of the first capacitor is generally less than 500uF, and the capacitance value of the second capacitor can be selected to be 1F or more, which is much greater than that of the first capacitor.

[0074] The first end of the third switch K3 is connected to the second end of the first switch K1, and the second end of the third switch K3 is connected to the input end of the seventh switch tube Q7.

[0075] The first end of the fourth switch K4 is connected to the first end of the third switch K3, and the second end of the fourth switch K4 is connected to the first end of the fourth coil L4.

[0076] The first end of the fifth switch K5 is connected to the common end of the first coil L1, the second coil L2 and the third coil L3, and the second end of the fifth switch K5 is connected to the first end of the fourth coil L4.

[0077] The first end of the sixth switch K6 is connected to the second end of the second switch K2, and the second end of the sixth switch K6 is connected to the output end of the eighth switch Q8.

[0078] The second end of the fourth coil L4 is connected to the common end between the seventh switch Q7 and the eighth switch Q8.

[0079] The output end of the seventh switch Q7 is connected to the input end of the eighth switch Q8, and the control ends of the seventh switch Q7 and the eighth switch Q8 are respectively connected to the control port of the second controller S2.

[0080] The second end of the third switch K3 is connected to the first end of the second capacitor C2, and the second end of the sixth switch K6 is connected to the second end of the second capacitor C2.

[0081] The first switch Q1 to the eighth switch Q8 are respectively connected in parallel with a diode.

[0082] The working modes in the high-voltage power-on mode, the driving mode, the ordinary charging mode, the boost charging mode, the parking heating mode and the high-voltage power-off mode will be introduced respectively.

[0083] (1) The high-voltage power-on mode refers to the process of switching the vehicle from the low-voltage standby state to the high-voltage active state. As shown in FIG. 1, in the high-voltage power-on mode, the specific implementation process is as follows: Figure 3

[0084] The first switch K1 is closed, the second switch K2 is closed, the third switch K3 is opened, the fourth switch K4 is opened, the fifth switch K5 is closed, and the sixth switch K6 is closed. The battery B is in a discharging mode at this time. The first switch Q1, at least one of the third switch Q3 and the fifth switch Q5, the eighth switch Q8, at least one of the first coil L1, the second coil L2 and the third coil L3, at least one of the second capacitor C2, the diode connected in parallel with the second switch Q2, the diode connected in parallel with the fourth switch Q4, the diode connected in parallel with the sixth switch Q6, and the diode connected in parallel with the seventh switch Q7 constitute a buck-boost circuit.

[0085] ​After the switches are set, the first controller S1 inputs a first pulse width modulation (PWM) signal to at least one of the first switch Q1, the third switch Q3, and the fifth switch Q5. The second controller S2 inputs the first PWM signal to the eighth switch Q8.

[0086] The working process of the entire circuit will be described below by taking the input of the first PWM signal to the third switch Q3 as an example. Under the action of the first PWM signal, the current output from the positive terminal of the battery passes through the third switch Q3 in a chopping manner, and then passes through the second coil L2, the fourth coil L4, the diode connected in parallel with the seventh switch Q7, and the first terminal of the second capacitor C2 to charge the second capacitor C2. Then, the current returns to the negative terminal of the battery through the second terminal of the second capacitor C2. Here, the battery B, the third switch Q3, the second coil L2, the fourth coil L4, the diode connected in parallel with the seventh switch Q7, and the second capacitor C2 form a charging circuit. The battery voltage is higher than the voltage of the second capacitor C2. In order to avoid excessive charging current caused by the continuous conduction of the third switch Q3, the third switch Q3 is controlled by the PWM signal. During the high level period of the PWM signal, the third switch Q3 is turned on, and the battery B charges the second capacitor C2. When the PWM signal is at a low level, the third switch Q3 is turned off, and the battery B stops charging the second capacitor C2. By adjusting the duty cycle of the PWM signal, the charging current is controlled.

[0087] When the first controller S1 inputs the first PWM signal to other switches or more switches (for example, the first switch Q1 and the fifth switch Q5) alone, the implementation process is similar to that of the third switch Q3, which will not be described here.

[0088] In the above scheme, the system is in a buck state, and the second capacitor is slowly charged to a voltage close to that of the battery, thereby avoiding excessive voltage difference between the two sides of the switch and generating a large inrush current at the closing moment, which causes the contactor to stick.

[0089] (2) The driving mode is the working mode of the vehicle during driving. In the driving mode, the specific implementation process is as follows:

[0090] At this time, the battery is in a discharging mode, the first switch K1 is closed, the second switch K2 is closed, the third switch K3 is closed, the fourth switch K4 is open, the fifth switch K5 is open, and the sixth switch K6 is closed. After the switches are set, the first controller S1 stops inputting a first pulse width modulation (PWM) signal to at least one of the first switch Q1, the third switch Q3, and the fifth switch Q5. The second controller S2 stops inputting the first PWM signal to the eighth switch Q8.

[0091] At this time, the second capacitor is connected in parallel across the inverter, thereby effectively suppressing the amplitude of the inverter bus voltage fluctuation, especially during rapid acceleration or deceleration driving of the whole vehicle, the second capacitor effectively absorbs the power fluctuation on the DC bus, so that the bus voltage in the inverter is more stable, which helps to improve the control stability of the inverter and maintain stable output performance; in addition, the vehicle driving has randomness, so the demand power fluctuation can be very large, the second capacitor can effectively absorb the power fluctuation of the motor, thereby reducing the output power fluctuation amplitude of the battery, which helps to prolong the service life of the battery; when a serious fault occurs during high-speed operation of the whole vehicle, the inverter stops current output immediately for self-protection, and the back electromotive force of the motor suddenly rises at high speed. At this time, the second capacitor will quickly absorb the impact current from the motor, thereby avoiding the serious impact of the sudden increase of the back electromotive force of the motor on the inverter and the high-voltage system of the whole vehicle, and even causing damage.

[0092] (3) The ordinary charging mode is a mode in which the charging pile and the battery voltage are matched. For example, the charging pile can charge a 400-volt battery, and the voltage of the battery is also 400 volts.

[0093] At this time, the battery is in charging mode, the first switch K1 is closed, the second switch K2 is closed, the third switch K3 is closed, the fourth switch K4 is open, the fifth switch K5 is open, and the sixth switch K6 is closed. After the switch is set, the first controller S1 stops inputting the first pulse width modulation PWM signal to at least one of the first switch tube Q1, the third switch tube Q3 and the fifth switch tube Q5. The second controller S2 stops inputting the first PWM signal to the eighth switch tube Q8.

[0094] At this time, the second capacitor can absorb the power fluctuation from the charging pile, making the charging power of the whole vehicle more stable, better protecting the battery, and effectively reducing the power fluctuation caused by the continuous adjustment of the output of the charging pile; during the charging process, for some reason, the whole vehicle urgently or accidentally cuts off the related contactor (such as the first switch and the second switch), but the charging pile still maintains the output, at this time, the second capacitor will effectively absorb the power from the charging pile, leaving enough fault response time for the charging pile, avoiding damage to the high-voltage system of the whole vehicle or the charging pile.

[0095] (4) The boost charging mode is a charging mode adopted to solve the compatibility problem of the battery and different voltage level charging piles. For example, when an 800-volt battery faces a 500-volt charging pile, it needs to switch to the boost charging mode.

[0096] Taking the charging pile as 500 volts and the battery as 800 volts as an example, since the charging pile can only accept charging for the battery below 500 volts. Therefore, the second capacitor C2 needs to be charged to about 400 volts, so that the charging pile will think that the battery is 400 volts, and will agree to charge the battery. For example,Figure 4 As shown,

[0097] The first switch K1 is closed, the second switch K2 is closed, the third switch K3 is open, the fourth switch K4 is open, the fifth switch K5 is closed, and the sixth switch K6 is closed. A boost-buck circuit is formed by at least one of the following: second switch Q2, fourth switch Q4, and sixth switch Q6; a seventh switch Q7; at least one of the following coils: first coil L1, second coil L2, and third coil L3; fourth coil L4; a diode connected in parallel with the eighth switch Q8; a second capacitor C2; and at least one of the following diodes connected in parallel with the first switch Q1, the third switch Q3, and the fifth switch Q5. After the switches are set, the first controller S1 inputs a second PWM signal to at least one of the second switch Q2, fourth switch Q4, and sixth switch Q6. The second controller S2 sends a second PWM signal to the seventh switch Q7.

[0098] The following explanation of the circuit's operation will take the input of a second PWM signal to the fourth switch Q4 as an example. When the fourth switch Q4 is turned on, the current output from the positive terminal of the second capacitor C2 charges the second coil L2 and the fourth coil L4. When the fourth switch Q4 is turned off, the electrical energy stored in the second coil L2 and the fourth coil L4 flows through the parallel diode of the third switch Q3 to the positive terminal of the battery, thus charging the battery. The charging current is controlled by the PWM signals of the fourth switch Q4 and the seventh switch Q7. Under the action of the second PWM signal, the charging current is controlled by adjusting the PWM duty cycle. Simultaneously, the voltage of the second capacitor C2 is gradually reduced to the target range (close to the rated voltage of the charging station).

[0099] When the first controller S1 inputs the second PWM signal to other switches or more switches (e.g., the second switch Q2 and the sixth switch Q6), the implementation process is similar to that of the fourth switch Q4, and will not be described in detail here.

[0100] When the voltage of the second capacitor C2 is approximately equal to the rated operating voltage of the charging pile, the first controller S1 stops inputting the second PWM signal to at least one of the second switch Q2, the fourth switch Q4, and the sixth switch Q6. The second controller S2 stops inputting the second PWM signal to the seventh switch Q7. The vehicle BMS controller sends a charging request to the charging pile.

[0101] At this time, at least one of the diode in parallel with the first switch tube Q1, the diode in parallel with the third switch tube Q3, the diode in parallel with the fifth switch tube Q5, the diode in parallel with the eighth switch tube Q8, at least one of the first coil L1, the second coil L2 and the third coil L3, the fourth coil L4, the seventh switch tube Q7, the second capacitor C2, at least one of the second switch tube Q2, the fourth switch tube Q4 and the sixth switch tube Q6 constitute a boost-buck circuit.

[0102] The first controller S1 inputs the third PWM signal to at least one of the second switch tube Q2, the fourth switch tube Q4 and the sixth switch tube Q6. The second controller S2 inputs the third PWM signal to the seventh switch tube.

[0103] The working process of the entire circuit will be described below by taking the input of the third PWM signal to the fourth switch tube Q4 as an example. The charging pile first charges the electric quantity into the second capacitor C2. Under the action of the third PWM signal, the current generated by the second capacitor C2 passes through the seventh switch tube Q7, the fourth coil L4, the second coil L2, and then flows into the positive terminal of the battery B through the diode in parallel with the third switch tube Q3, and then flows into the second terminal of the second capacitor C2 from the negative terminal of the battery B. By adjusting the duty cycle of the PWM, the charging current is controlled.

[0104] When the first controller S1 inputs the third PWM signal to other switch tubes or more switch tubes (for example, the second switch tube Q2 and the sixth switch tube Q6) alone, the implementation process is similar to that of the fourth switch tube Q4, which will not be described here.

[0105] After the charging is completed, the whole vehicle BMS controller sends a request to stop charging to the charging pile. The battery B changes from the charging mode to the discharging mode. Since the voltage of the second capacitor C2 is relatively low at this time, the second capacitor C2 needs to be boosted to be close to the voltage difference between the two terminals of the inverter, so that the second capacitor C2 can be connected in parallel across the inverter.

[0106] The first controller S1 stops inputting the third PWM signal to at least one of the second switch tube Q2, the fourth switch tube Q4 and the sixth switch tube Q6. The second controller S2 stops inputting the third PWM signal to the seventh switch tube Q7. In addition, the first controller S1 is configured to input the first PWM signal to at least one of the first switch tube Q1, the third switch tube Q3 and the fifth switch tube Q5. The second controller S2 inputs the first PWM signal to the eighth switch tube Q8.

[0107] At this time, the first switch tube Q1, at least one of the third switch tube Q3, the fifth switch tube Q5, the eighth switch tube Q8, at least one of the first coil L1, the second coil L2, the third coil L3, the fourth coil L4, the diode connected in parallel with the seventh switch tube Q7, and at least one of the diode connected in parallel with the second switch tube Q2, the diode connected in parallel with the fourth switch tube Q4, and the diode connected in parallel with the sixth switch tube Q6 constitute a buck-boost circuit.

[0108] After the switch is set, the first controller S1 inputs the first PWM signal to at least one of the first switch tube Q1, the third switch tube Q3, and the fifth switch tube Q5. The second controller S2 inputs the first PWM signal to the eighth switch tube Q8.

[0109] The working process of the entire circuit will be described below by taking the input of the first PWM signal to the third switch tube Q3 as an example. Under the action of the first PWM signal, the current output from the positive terminal of the battery passes through the third switch tube Q3 in a chopping manner, and the current passes through the second coil L2, the fourth coil L4, the diode connected in parallel with the seventh switch tube Q7, and the first terminal of the second capacitor C2, and charges the second capacitor C2, and then the current returns to the negative terminal of the battery through the second terminal of the second capacitor C2. Here, the battery B, the third switch tube Q3, the second coil L2, the fourth coil L4, the diode connected in parallel with the seventh switch tube Q7, and the second capacitor C2 constitute a charging circuit. In order to avoid excessive charging current due to the continuous conduction of the third switch tube Q3, the third switch tube Q3 is controlled by the PWM signal. During the high level period of the PWM signal, the third switch tube Q3 is turned on, and the battery B charges the second capacitor C2. When the PWM signal is low, the third switch tube Q3 is closed, and the battery B stops charging the second capacitor C2. By adjusting the duty cycle of the PWM, the charging current is controlled.

[0110] When the first controller S1 inputs the first PWM signal to other switch tubes or more switch tubes (for example, the first switch tube Q1 and the fifth switch tube Q5) alone, the implementation process is similar to that of the third switch tube Q3, which will not be described here.

[0111] When the voltage of the second capacitor and the voltage of the battery are substantially the same, the third switch K3 is closed and the fifth switch K5 is opened, so that the second capacitor is connected in parallel across the inverter.

[0112] In the above scheme, since the voltage of the battery is relatively high and the voltage of the charging pile is relatively low, the second capacitor can be charged to the vicinity of the rated working voltage of the charging pile first, a charging request can be sent to the charging pile, then the battery changes from the discharging mode to the charging mode, the first controller is configured to input the third PWM signal to at least one of the second switch tube, the fourth switch tube and the sixth switch tube, and the second controller is configured to input the third PWM signal to the seventh switch tube, at this time, the system is in the boost mode, and the voltage can be increased to charge the battery.

[0113] (5) The parking heating mode is a mode for heating the battery in a parking state of the vehicle in a low temperature environment to recover the performance of the battery as much as possible. In order to heat the battery in the vehicle, the charging and discharging operation on the second capacitor C2 can be switched frequently to heat the battery.

[0114] The first switch K1 is closed, the second switch K2 is closed, the third switch K3 is opened, the fourth switch K4 is opened, the fifth switch K5 is closed, and the sixth switch K6 is closed.

[0115] When discharging the second capacitor C2, the first controller S1 stops inputting the first PWM signal to at least one of the first switch tube Q1, the third switch tube Q3 and the fifth switch tube Q5; the second controller S2 stops inputting the first PWM signal to the eighth switch tube Q8; and the first controller S1 inputs the fourth PWM signal to at least one of the second switch tube Q2, the fourth switch tube Q4 and the sixth switch tube Q6. The second controller S2 inputs the fourth PWM signal to the seventh switch tube, and the eighth switch tube Q8 is closed. The working principle of discharging the second capacitor is described above, which will not be described here.

[0116] When the voltage of the second capacitor C2 is less than or equal to the lower limit value of the voltage, the discharging mode of the second capacitor C2 is switched to the charging mode of the second capacitor C2, the first controller S1 is configured to stop inputting the fourth PWM signal to at least one of the second switch tube Q2, the fourth switch tube Q4 and the sixth switch tube Q6, and the second controller S2 stops inputting the fourth PWM signal to the seventh switch tube Q7; the first controller S1 inputs the fifth PWM signal to at least one of the first switch tube Q1, the third switch tube Q3 and the fifth switch tube Q5. The second controller inputs the fifth PWM signal to the eighth switch tube Q8.

[0117] When the voltage of the second capacitor C2 is greater than or equal to the upper limit value of the voltage, the charging mode of the second capacitor C2 is switched to the discharging mode of the second capacitor C2.

[0118] The above steps are repeatedly executed until a stop heating command is received.

[0119] (6) The driving heating mode is a mode that heats the battery in order to restore battery performance as much as possible when the temperature is low and the vehicle is in motion. In order to heat the battery in the vehicle, the charging and discharging operation of the second capacitor C2 can be switched continuously to heat the battery.

[0120] When the first switch K1 is closed, the second switch K2 is closed, the third switch K3 is open, the fourth switch K4 is closed, the fifth switch K5 is open, and the sixth switch K6 is closed, none of the coils in the motor can be used. Therefore, the fourth coil L4, the eighth switch Q8, the diode connected in parallel with the seventh switch Q7, and the second capacitor C2 constitute a buck circuit.

[0121] The first controller S1 stops inputting the first PWM signal to at least one of the first switch Q1, the third switch Q3 and the fifth switch Q5;

[0122] The second controller S2 inputs the fourth PWM signal to the eighth switch Q8. The second controller S2 then turns off the seventh switch Q7.

[0123] like Figure 5 As shown, under the action of the fourth PWM signal, the current output from the positive terminal of the battery is chopped through the fourth coil L4, the diode connected in parallel with the seventh switch Q7, and input to the first terminal of the second capacitor C2, charging the second capacitor C2. Then, the current returns to the negative terminal of the battery through the second terminal of the second capacitor C2. To achieve controllable charging current, the eighth switch Q8 is controlled by the PWM signal. When the PWM is high, the fourth coil L4 is charged; when the PWM is low, the current in the fourth coil L4 freewheels through the diode connected in parallel with the seventh switch Q7 to the second capacitor C2, thereby charging the second capacitor C2. This causes the voltage of the second capacitor C2 to be higher than the battery voltage.

[0124] When the voltage of the second capacitor C2 is greater than or equal to the upper voltage limit, the system switches from charging mode to discharging mode for the second capacitor C2. The second controller S2 inputs the fifth PWM signal to the seventh switch Q7. The second controller S2 then turns off the eighth switch Q8.

[0125] like Figure 6 As shown, under the action of the fifth PWM signal, the current generated by the second capacitor C2 flows through the seventh switch Q7, the fourth coil L4, and then into the positive terminal of battery B. The current then flows from the negative terminal of battery B into the second terminal of the second capacitor C2. The discharge process will cause the voltage of the second capacitor C2 to drop, but it will still be higher than the voltage of battery B.

[0126] Repeat the above steps until a stop heating command is received.

[0127] (7) High-voltage power-off mode refers to the process of switching the vehicle from the high-voltage system activation state to the low-voltage standby state. Since high voltage exists in the part of the circuit in the high-voltage power-off state, the amount of electricity in the second capacitor needs to be charged into the battery.

[0128] The first switch K1 is closed, the second switch K2 is closed, the third switch K3 is open, the fourth switch K4 is open, the fifth switch K5 is closed, and the sixth switch K6 is closed. After the switch is set, the first controller S1 inputs the sixth PWM signal to at least one of the second switch tube Q2, the fourth switch tube Q4, and the sixth switch tube Q6, and the second controller S2 inputs the sixth PWM signal to the seventh switch tube Q7. At this time, the second capacitor C2 is in the discharging mode, and the specific working principle is described in the process of discharging the second capacitor C2 in the foregoing.

[0129] In the case where the voltage of the second capacitor C2 is less than or equal to the safety voltage, the first controller S1 is configured to stop inputting the sixth PWM signal to at least one of the second switch tube Q2, the fourth switch tube Q4, and the sixth switch tube Q6, and the second controller S2 stops inputting the sixth PWM signal to the seventh switch tube Q7. The first switch K1, the second switch K2, the third switch K3, the fourth switch K4, the fifth switch K5, and the sixth switch K6 are all open. At this time, the inverter performs active discharge to release the amount of electricity in the first capacitor C1 through the motor, so that the voltage of the first capacitor C1 is reduced to below the target safety voltage.

[0130] In the embodiments described above, the whole or part of the embodiments can be implemented by software, hardware, firmware or any combination thereof. When implemented by software, the whole or part of the embodiments can be implemented in the form of a computer program product. The computer program product includes one or more computer instructions loaded on a computer and executed, and generates the processes or functions described in the embodiments of the present application. The computer can be a general purpose computer, a special purpose computer, a computer network or other programmable apparatus. The computer instructions can be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions can be transmitted from one network site, computer, server or data center to another network site, computer, server or data center through wired (such as coaxial cable, optical fiber, digital subscriber line) or wireless (such as infrared, microwave, etc.) manner. The computer readable storage medium can be any available medium accessible by a computer, and can also be a data storage device such as a server, data center, etc. integrated with one or more available media. The available medium can be a magnetic medium (such as floppy disk, hard disk, magnetic tape, etc.), an optical medium (such as DVD, etc.), or a semiconductor medium (such as solid state disk), etc. In the above described embodiments, the description of each embodiment has its own emphasis, and the part not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

Claims

1. A multifunctional device applied to a high-pressure system of a vehicle, characterized in that, The application relates to a power supply, an inverter and a motor. The power supply comprises a first switch, a battery and a second switch connected in series, wherein the first end of the first switch is connected to the first end of the battery, and the second end of the battery is connected to the first end of the second switch. The inverter comprises a first controller, a first branch, a second branch, a third branch and a fourth branch arranged in parallel, wherein the first branch comprises a first capacitor, the second branch comprises a first switch tube and a second switch tube connected in series, the third branch comprises a third switch tube and a fourth switch tube connected in series, and the fourth branch comprises a fifth switch tube and a sixth switch tube connected in series; the control ends of the first switch tube to the sixth switch tube are connected to the first controller respectively; and the inverter and the power supply are connected in parallel. The motor comprises a first coil, a second coil and a third coil, wherein the first end of the first coil is connected to the common end of the first switch tube and the second switch tube, the first end of the second coil is connected to the common end of the third switch tube and the fourth switch tube, and the first end of the third coil is connected to the common end of the fifth switch tube and the sixth switch tube; and the second end of the first coil, the second end of the second coil and the second end of the third coil are connected. The multifunctional device comprises a third switch, a fourth switch, a fifth switch, a sixth switch, a fourth coil, a seventh switch tube, an eighth switch tube, a second capacitor and a second controller, wherein the first end of the third switch is connected to the second end of the first switch, the second end of the third switch is connected to the input end of the seventh switch tube, the first end of the fourth switch is connected to the first end of the third switch, the second end of the fourth switch is connected to the first end of the fourth coil, the first end of the fifth switch is connected to the common end of the first coil, the second coil and the third coil, the second end of the fifth switch is connected to the first end of the fourth coil, the first end of the sixth switch is connected to the second end of the second switch, the second end of the sixth switch is connected to the output end of the eighth switch tube, the second end of the fourth coil is connected to the common end between the seventh switch tube and the eighth switch tube, the output end of the seventh switch tube is connected to the input end of the eighth switch tube, and the control ends of the seventh switch tube and the eighth switch tube are connected to the control ports of the second controller respectively; the second end of the third switch is connected to the first end of the second capacitor, the second end of the sixth switch is connected to the second end of the second capacitor, and the first switch tube to the eighth switch tube are respectively connected in parallel with diodes.

2. The multifunction device for use in a high-voltage system of a vehicle according to claim 1, characterized by, In a high-voltage power-on mode, the first switch is closed, the second switch is closed, the third switch is opened, the fourth switch is opened, the fifth switch is closed, and the sixth switch is closed, the first controller is used for inputting a first pulse width modulation (PWM) signal to at least one of the first switch tube, the third switch tube and the fifth switch tube, and the second controller is used for inputting a first PWM signal to the eighth switch tube.

3. The multifunction device for use in a high-voltage system of a vehicle according to claim 2, characterized by, In a transition from the high-voltage power-on mode to a driving mode, the third switch is closed, the fifth switch is opened, and the sixth switch is closed, The first controller is configured to stop inputting the first PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to stop inputting the first PWM signal to the eighth switch.

4. The multifunction device for use in a high-voltage system of a vehicle according to claim 2, characterized by, In the conversion from the high-voltage power-on mode to the ordinary charging mode, The third switch is closed, the fifth switch is opened, and the sixth switch is closed. The first controller is configured to stop inputting the first PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to stop inputting the first PWM signal to the eighth switch.

5. The multifunction device for use in a high-voltage system of a vehicle according to claim 2, characterized by, In the conversion from the high-voltage power-on mode to the boost charging mode, The first controller is configured to input the second PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to input the second PWM signal to the seventh switch. In the case where the voltage of the second capacitor is approximately equal to the rated working voltage of the charging pile, the first controller is configured to stop inputting the second PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to stop inputting the second PWM signal to the seventh switch. In the case where the BMS controller sends a charging request to the charging pile, the first controller is configured to input the third PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to input the third PWM signal to the seventh switch.

6. The multifunctional device applied to a high-voltage system of a vehicle according to claim 5, wherein In the case where the BMS controller sends a stop charging request to the charging pile, the first controller is configured to stop inputting the third PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to stop inputting the third PWM signal to the seventh switch. The first controller is configured to input the first PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to input the first PWM signal to the eighth switch. The third switch is closed, and the fifth switch is opened.

7. The multifunction device for use in a high-voltage system of a vehicle according to claim 2, characterized by, In the conversion from the high-voltage power-on mode to the parking heating mode, The first controller is configured to stop inputting the first PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to stop inputting the first PWM signal to the eighth switch. The first controller is configured to input the fourth PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to input the fourth PWM signal to the seventh switch, and the eighth switch is closed. The first controller is configured to stop inputting the fourth PWM signal to at least one of the second switch, the fourth switch and the sixth switch, and the second controller is configured to stop inputting the fourth PWM signal to the seventh switch when the voltage of the second capacitor is less than or equal to the lower limit value of the voltage. The first controller is configured to input the fifth PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to input the fifth PWM signal to the eighth switch.

8. The multifunction device for use in a high-voltage system of a vehicle according to claim 2, characterized by, In the process of converting from the high-voltage power-on mode to the driving heating mode, The fourth switch is closed, and the fifth switch is opened, The first controller is configured to stop inputting the first PWM signal to at least one of the first switch, the third switch and the fifth switch, and the second controller is configured to stop inputting the first PWM signal to the eighth switch. The second controller is configured to input the fourth PWM signal to the seventh switch. The second controller is configured to control the eighth switch to be closed. The second controller is configured to stop inputting the fourth PWM signal to the seventh switch when the voltage of the second capacitor is less than or equal to the lower limit value of the voltage. The second controller is configured to input the fifth PWM signal to the eighth switch.

9. The multifunction device for use in a high voltage system of a vehicle according to claim 2, characterized by, In the process of converting from the high-voltage power-on mode to the high-voltage power-off mode, The second controller is configured to input the sixth PWM signal to the seventh switch. The first controller is configured to input the sixth PWM signal to at least one of the second switch, the fourth switch and the sixth switch. The second controller is configured to stop inputting the sixth PWM signal to the seventh switch when the voltage of the second capacitor is less than or equal to the safety voltage, and the first controller is configured to stop inputting the sixth PWM signal to at least one of the second switch, the fourth switch and the sixth switch. The first switch, the second switch, the third switch, the fourth switch, the fifth switch and the sixth switch are all opened.

10. A vehicle characterized by comprising: A multifunctional device for a high-voltage system of a vehicle, comprising any one of claims 1 to 9.

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