A hybrid electric power distribution system and method for a vehicle

Abstract

This invention discloses a hybrid electric power distribution system and method for vehicles, relating to the field of electrical signal detection. The hybrid electric power distribution system includes: a main circuit for supplying electrical energy from a battery or supercapacitor to vehicle loads; and a detection and control circuit for detecting the power of the battery and DC bus, and detecting the voltage of the supercapacitor, to control the switching of the main circuit, thereby controlling the battery or supercapacitor to supply power to the vehicle loads. The advantages of this invention are: by detecting the power of the battery to determine its charge level, the detection result is more accurate than voltage-based detection, avoiding misjudgments caused by the battery's "phantom charge" phenomenon, which leads to coarse power distribution and low energy utilization in the vehicle power distribution system; and by using a hybrid power supply of battery and supercapacitor, with priority given to supercapacitor power supply, the energy utilization rate is increased due to the low internal resistance and fast charging and discharging speed of supercapacitors.

Description

Technical Field

[0001] This invention relates to the field of electrical signal detection, specifically to a hybrid electric power distribution system and method for vehicles. Background Technology

[0002] The types and numbers of automotive electrical equipment, including hybrid power systems, are increasing daily. These systems have various loads connected to their power buses, resulting in fluctuating power outputs. This presents challenges in system design, posing difficulties in simultaneously improving operational efficiency and conserving energy. In recent years, in particular, with the increasing use of parking air conditioning, the adoption of hybrid power systems for vehicle power supply has become a development trend, while also placing higher demands on power distribution.

[0003] Currently, in vehicle power distribution systems composed entirely of batteries, issues such as improper battery storage location, battery aging, temperature variations, and improper charging or maintenance can cause the battery to exhibit a "phantom charge" phenomenon. Power distribution is achieved by using voltage detection to control switch switching, but this cannot accurately detect the actual battery charge level, resulting in a coarse power distribution and low energy utilization. Improvements are needed. Summary of the Invention

[0004] The purpose of this invention is to provide a hybrid electric power distribution system and method for vehicles to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A hybrid electric power distribution system for vehicles, comprising:

[0007] The main circuit is used to supply electrical energy from the battery or supercapacitor to the vehicle load;

[0008] The detection and control circuit is used to detect the power of the battery and DC bus, and the voltage of the supercapacitor, in order to control the switching of the main circuit, and thus control the battery or supercapacitor to supply power to the vehicle load; and control the charging of the battery or supercapacitor.

[0009] The output of the main circuit is connected to the input of the detection and control circuit, and the output of the detection and control circuit is connected to the input of the main circuit.

[0010] As a further embodiment of the present invention: the main circuit includes a first DC-DC converter, a second DC-DC converter, a third DC-DC converter, a first switch, a second switch, a third switch, and a DC bus. The first end of the first DC-DC converter is connected to a supercapacitor, one end of the third switch, and the input end of the detection and control circuit. The second end of the first DC-DC converter is connected to one end of the first switch, and the other end of the first switch is connected to the DC bus. The other end of the third switch is connected to the second end of the third DC-DC converter. The first end of the third DC-DC converter is connected to the first end of the second DC-DC converter, the input end of the detection and control circuit, and a battery. The second end of the second DC-DC converter is connected to one end of the second switch, and the other end of the second switch is connected to the DC bus. The DC bus is connected to the vehicle load through an AC transformer. The voltage and current signals on the DC bus are output to the detection and control circuit.

[0011] As a further embodiment of the present invention: the detection control circuit includes:

[0012] The first power detector is used to detect the voltage Ubus and current Ibus on the DC bus, obtain the power Pbus on the DC bus, and output it to the judgment and control module.

[0013] The second power detector is used to detect the battery voltage Ud and current Id, obtain the battery power Pd, and output it to the judgment and control module.

[0014] The judgment and control module is used to receive the voltage Uc of the supercapacitor, the power Pbus of the DC bus, and the power Pd of the battery to determine the power information of the battery and supercapacitor, and output the control logic signal K. ∑ Controls the main circuit switch; controls the battery or supercapacitor to supply power when the vehicle load is using electricity; controls the battery or supercapacitor to charge when the vehicle load is generating electricity.

[0015] The input terminal of the first power detector is connected to the output terminal of the main circuit, the input terminal of the second power detector is connected to the output terminal of the main circuit, the output terminal of the first power detector is connected to the first input terminal of the judgment control module, the output terminal of the second power detector is connected to the second input terminal of the judgment control module, the third input terminal of the judgment control module collects the voltage information of the supercapacitor, and the output terminal of the judgment control module is connected to the input terminal of the main circuit.

[0016] As a further aspect of the present invention: the fourth input terminal of the determination control module collects the battery voltage Ud.

[0017] A method for distributing electric power in a hybrid vehicle includes the following steps:

[0018] Step S1: Obtain the voltage Ubus and current Ibus on the DC bus, obtain the voltage Ud and current Id of the battery, obtain the voltage Uc of the supercapacitor; obtain the power Pbus of the DC bus and the power Pd of the battery.

[0019] Step S2: The current value Ibus is positively determined by the direction from the DC bus to the vehicle load. It is then determined whether the power Pbus of the DC bus is greater than or equal to 0, and thus whether the vehicle load is using or generating electricity.

[0020] Step S3: If Pbus≥0, the vehicle load is in a power-consuming state; determine the difference between the voltage Uc of the supercapacitor and the preset voltage Ucm of the supercapacitor; if Uc≥Ucm, close the first switch and open the second switch, and the supercapacitor supplies power to the vehicle load through the DC bus; if Uc<Ucm, determine the difference between the power Pd of the battery and the preset power Pdm of the battery; if Pd≥Pdm, close the second switch and open the first switch, and the battery supplies power to the vehicle load through the DC bus.

[0021] Step S4: If Pbus < 0, the vehicle load is in the power generation state; the vehicle load prioritizes charging the supercapacitor, and after the supercapacitor is fully charged, it then charges the battery.

[0022] As a further aspect of the present invention: In step S3, when Pd≥Pdm, while closing the second switch and opening the first switch, the third switch is closed, and the supercapacitor charges the battery while the battery supplies power to the vehicle load through the DC bus.

[0023] As a further aspect of the present invention: in step S3, if Pd < Pdm, the first switch and the second switch are disconnected, the third switch is closed, and the battery is charged by the supercapacitor.

[0024] As a further embodiment of the present invention: In step S4, if Pbus < 0, the magnitude between the voltage Uc of the supercapacitor and the preset value Ucm of the supercapacitor voltage is determined. If Uc < Ucm, the first switch is closed, and the second and third switches are opened, and the vehicle load generates electricity to charge the supercapacitor. If Uc ≥ Ucm, the magnitude between the power Pd of the battery and the preset value Pdm of the battery power is determined. If Pd < Pdm, the second switch is closed, and the first and third switches are opened, and the vehicle load generates electricity to charge the battery. If Pd ≥ Pdm, the first, second, and third switches are opened.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention determines the battery capacity by detecting the battery power, which is more accurate than the voltage method and avoids misjudgment caused by the battery's "phantom charge" phenomenon, thus preventing the problem of coarse power distribution and low energy utilization in the vehicle's power distribution system; at the same time, it uses a hybrid power supply of batteries and supercapacitors, with priority given to supercapacitor power supply. Based on the low internal resistance and fast charging and discharging speed of supercapacitors, the energy utilization rate is increased. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of a hybrid electric power distribution system for vehicles.

[0027] Figure 2 This is a flowchart illustrating a method for distributing electric power in a hybrid vehicle. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0029] Please see Figure 1 A hybrid electric power distribution system for vehicles, comprising:

[0030] The main circuit is used to supply electrical energy from the battery or supercapacitor to the vehicle load;

[0031] The detection and control circuit is used to detect the power of the battery and DC bus Vbus, and the voltage of the supercapacitor, in order to control the switching of the main circuit, and thus control the battery or supercapacitor to supply power to the vehicle load; and control the charging of the battery or supercapacitor.

[0032] The output of the main circuit is connected to the input of the detection and control circuit, and the output of the detection and control circuit is connected to the input of the main circuit.

[0033] In this embodiment: Please refer to Figure 1The main circuit includes a first DC / DC converter DC / DC1, a second DC / DC converter DC / DC2, a third DC / DC converter DC / DC3, a first switch K1, a second switch K2, a third switch K3, and a DC bus Vbus. The first terminal of the first DC / DC converter DC / DC1 is connected to a supercapacitor, one terminal of the third switch K3, and the input terminal of the detection and control circuit. The second terminal of the first DC / DC converter DC / DC1 is connected to one terminal of the first switch K1, and the other terminal of the first switch K1 is connected to the DC bus Vbus. The other terminal of the third switch K3 is connected to the second terminal of the third DC / DC converter DC / DC3. The first terminal of the third DC / DC converter DC / DC3 is connected to the first terminal of the second DC / DC converter DC / DC2, the input terminal of the detection and control circuit, and a battery. The second terminal of the second DC / DC converter DC / DC2 is connected to one terminal of the second switch K2, and the other terminal of the second switch K2 is connected to the DC bus Vbus. The DC bus Vbus is connected to the vehicle load through an AC transformer. The voltage and current signals on the DC bus Vbus are output to the detection and control circuit.

[0034] The first DC / DC converter (DC / DC1), the second DC / DC converter (DC / DC2), and the third DC / DC converter (DC / DC3) are all bidirectional DC / DC converters. When the first switch K1 is closed and the vehicle load is in a powered state, the supercapacitor is transformed to the DC bus Vbus through the first DC / DC converter (DC / DC1). The output voltage of the DC bus Vbus powers the electric drive motor M1 (bidirectional transformer) through the first AC / DC converter (DC / AC1) and the air conditioning motor M2 through the second AC / DC converter (DC / AC2). This example uses two vehicle loads (electric drive motor M1 and air conditioning motor M2), but the actual vehicle load is not limited. When the vehicle load is in a generating state (the electric drive motor M1 generates electricity when the car is in a rolling hill or braking energy recovery state), the generated electricity from the vehicle load powers the DC bus Vbus through the AC / DC converter, and the DC bus Vbus powers the supercapacitor through the first DC / DC converter (DC / DC1).

[0035] When the second switch K2 is closed, and the vehicle load is in a power-consuming state, the battery supplies power to the DC bus Vbus through the second DC / DC converter DC / DC2 and the second switch K2. The DC bus Vbus then supplies power to the vehicle load through the AC / DC conversion transformer. When the vehicle load is in a power-generating state, the load generates power to supply power to the DC bus Vbus through the AC / DC conversion transformer. The DC bus Vbus then supplies power to the battery through the second DC / DC converter DC / DC2.

[0036] Here, we take the first switch K1, the second switch K2, and the third switch K3 as examples. In actual use, it is not limited to three switches. For example, the three switches can be changed to six switches. During the bidirectional conversion process of the DC-DC converter, each conversion direction corresponds to a switch.

[0037] In this embodiment: Please refer to Figure 1 The detection control circuit includes:

[0038] The first power detector P1 is used to detect the voltage Ubus and current Ibus on the DC bus Vbus, obtain the power Pbus of the DC bus Vbus, and output it to the judgment and control module.

[0039] The second power detector P2 is used to detect the battery voltage Ud and current Id, obtain the battery power Pd, and output it to the judgment and control module.

[0040] The judgment control module (which can be implemented using a microcontroller) receives the voltage Uc of the supercapacitor, the power Pbus of the DC bus Vbus, and the power Pd of the battery to determine the power information of the battery and supercapacitor, and outputs the control logic signal K. ∑ Controls the main circuit switch; controls the battery or supercapacitor to supply power when the vehicle load is using electricity; controls the battery or supercapacitor to charge when the vehicle load is generating electricity.

[0041] The input terminal of the first power detector P1 is connected to the output terminal of the main circuit, the input terminal of the second power detector P2 is connected to the output terminal of the main circuit, the output terminal of the first power detector P1 is connected to the first input terminal of the judgment control module, the output terminal of the second power detector P2 is connected to the second input terminal of the judgment control module, the third input terminal of the judgment control module collects the voltage information of the supercapacitor, and the output terminal of the judgment control module is connected to the input terminal of the main circuit.

[0042] The power Pbus of the DC bus Vbus and the power Pd of the battery are obtained through the first power detector P1 and the second power detector P2. The voltage Uc of the supercapacitor is directly obtained (the supercapacitor does not exhibit virtual voltage, so power detection is unnecessary). Based on the power Pbus of the DC bus Vbus, it is determined whether the vehicle load is using electricity or generating electricity. Based on the voltage Uc of the supercapacitor, it is determined whether the supercapacitor needs charging and whether it has sufficient charge for power supply. Based on the power Pd of the battery, it is determined whether the battery needs charging and whether it has sufficient charge for power supply. This information is used to obtain the control logic signal K. ∑ The system controls the opening or closing of the first switch K1, the second switch K2, and the third switch K3 to achieve priority charging and discharging of the supercapacitor. The battery discharges when the supercapacitor is low on power and recharges when the supercapacitor is fully charged.

[0043] In this embodiment: Please refer to Figure 1 The fourth input terminal of the control module is used to collect the battery voltage Ud.

[0044] The battery voltage Ud can serve as a backup method. When the second power detector P2 fails, the system can directly revert to the traditional voltage method to determine the battery capacity. Although the detection results are not accurate enough, it can maintain the normal operation of the system.

[0045] In this embodiment: Please refer to Figure 2 A method for distributing electric power in a hybrid vehicle includes the following steps:

[0046] Step S1: Obtain the voltage Ubus and current Ibus on the DC bus Vbus, obtain the voltage Ud and current Id of the battery, obtain the voltage Uc of the supercapacitor; obtain the power Pbus of the DC bus Vbus and the power Pd of the battery.

[0047] Step S2: The current value Ibus is positively determined by the direction from the DC bus Vbus to the vehicle load. It is then determined whether the power Pbus of the DC bus Vbus is greater than or equal to 0, and thus whether the vehicle load is using or generating electricity.

[0048] Step S3: If Pbus≥0, the current flows to the vehicle load, and the vehicle load is in a powered state. Since the internal resistance of the supercapacitor is much smaller than that of the battery, its charge / discharge cycles and charge / discharge speed are much greater than those of the battery. That is, the supercapacitor charges the DC bus Vbus first, which is more efficient. Determine the difference between the supercapacitor voltage Uc and the supercapacitor voltage preset value Ucm. If Uc≥Ucm, the supercapacitor has sufficient charge. Close the first switch K1 and open the second switch K2. The supercapacitor supplies power to the vehicle load through the DC bus Vbus. If Uc<Ucm, the supercapacitor has insufficient charge. Because the battery has a virtual charge phenomenon, the voltage detection method cannot accurately reflect the battery's stored power. Therefore, the power detection method is used to correctly reflect and determine the battery's stored power. Determine the difference between the battery power Pd and the battery power preset value Pdm. If Pd≥Pdm, the battery has sufficient charge. Close the second switch K2 and open the first switch K1. The battery supplies power to the vehicle load through the DC bus Vbus.

[0049] Step S4: If Pbus < 0, the vehicle load outputs current and is in the power generation state. The vehicle load prioritizes charging the supercapacitor (the internal resistance of the supercapacitor is much smaller than that of the battery, and its charge / discharge cycles and charging / discharging speed are much greater than those of the battery). After the supercapacitor is fully charged, it then charges the battery.

[0050] In this embodiment: Please refer to Figure 2In step S3, when Pd≥Pdm, while closing the second switch K2 and opening the first switch K1, the third switch K3 is closed. When the battery supplies power to the vehicle load through the DC bus Vbus, the supercapacitor charges the battery.

[0051] At this point, the supercapacitor's charge is insufficient to power the vehicle's load. Therefore, the battery is powered through the third switch K3 and the third DC / DC converter DC / DC3, allowing the battery to power for a longer period.

[0052] In this embodiment: Please refer to Figure 2 In step S3, if Pd < Pdm, disconnect the first switch K1 and the second switch K2, close the third switch K3, and charge the supercapacitor with the battery.

[0053] At this time, both the battery and the supercapacitor are low on power. Since the internal resistance of the supercapacitor is much smaller than that of the battery, its charge / discharge cycles and charge / discharge speed are much greater than those of the battery. Therefore, the battery supplies power to the supercapacitor through the third DC / DC converter DC / DC3 and the third switch K3, so that the supercapacitor recovers to Pd > Pdm in a shorter time and can supply power to the vehicle load more quickly.

[0054] In this embodiment: Please refer to Figure 2 In step S4, if Pbus < 0, the supercapacitor is charged first. The voltage Uc of the supercapacitor is compared with the preset voltage Ucm of the supercapacitor. If Uc < Ucm, the first switch K1 is closed and the second switch K2 and the third switch K3 are opened. The vehicle load generates electricity to charge the supercapacitor. If Uc ≥ Ucm, the supercapacitor has sufficient power and does not need to be charged. The battery needs to be charged. The power Pd of the battery is compared with the preset power Pdm of the battery. If Pd < Pdm, the second switch K2 is closed and the first switch K1 and the third switch K3 are opened. The vehicle load generates electricity to charge the battery. If Pd ≥ Pdm, the first switch K1, the second switch K2, and the third switch K3 are opened.

[0055] In addition, if Pd < Pdm, the second switch K2 and the third switch K3 can be closed, and the first switch K1 can be opened; that is, the vehicle load and the supercapacitor supply power to the battery at the same time, which can shorten the battery charging time.

[0056] This invention determines the battery's capacity by detecting its power output. Compared to voltage-based detection, this method provides more accurate results and avoids misjudgments caused by the battery's apparent charge level, which leads to coarse power distribution and low energy utilization in vehicle power distribution systems. Furthermore, it employs a hybrid power supply method using both batteries and supercapacitors, prioritizing the use of supercapacitors. This leverages the low internal resistance and fast charging / discharging speed of supercapacitors to increase energy utilization.

[0057] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered in all respects as exemplary and not restrictive.

[0058] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A hybrid electric power distribution system for vehicles, characterized in that, The vehicle's hybrid electric power distribution system includes: The main circuit is used to supply electrical energy from the battery or supercapacitor to the vehicle load; The detection and control circuit is used to detect the power of the battery and DC bus, and the voltage of the supercapacitor, in order to control the switching of the main circuit, and thus control the battery or supercapacitor to supply power to the vehicle load; and control the charging of the battery or supercapacitor. The output of the main circuit is connected to the input of the detection and control circuit, and the output of the detection and control circuit is connected to the input of the main circuit. The main circuit includes a first DC-DC converter, a second DC-DC converter, a third DC-DC converter, a first switch, a second switch, a third switch, and a DC bus. The first end of the first DC-DC converter is connected to a supercapacitor, one end of the third switch, and the input end of the detection and control circuit. The second end of the first DC-DC converter is connected to one end of the first switch, and the other end of the first switch is connected to the DC bus. The other end of the third switch is connected to the second end of the third DC-DC converter. The first end of the third DC-DC converter is connected to the first end of the second DC-DC converter, the input end of the detection and control circuit, and the battery. The second end of the second DC-DC converter is connected to one end of the second switch, and the other end of the second switch is connected to the DC bus. The DC bus is connected to the vehicle load through an AC transformer. The voltage and current signals on the DC bus are output to the detection and control circuit. The detection control circuit includes: The first power detector is used to detect the voltage Ubus and current Ibus on the DC bus, obtain the power Pbus on the DC bus, and output it to the judgment and control module. The second power detector is used to detect the battery voltage Ud and current Id, obtain the battery power Pd, and output it to the judgment and control module. The judgment and control module is used to receive the voltage Uc of the supercapacitor, the power Pbus of the DC bus, and the power Pd of the battery to determine the power information of the battery and supercapacitor, and output the control logic signal K. ∑ Controls the main circuit switch; controls the battery or supercapacitor to supply power when the vehicle load is using electricity; controls the battery or supercapacitor to charge when the vehicle load is generating electricity. The input terminal of the first power detector is connected to the output terminal of the main circuit, the input terminal of the second power detector is connected to the output terminal of the main circuit, the output terminal of the first power detector is connected to the first input terminal of the judgment control module, the output terminal of the second power detector is connected to the second input terminal of the judgment control module, the third input terminal of the judgment control module collects the voltage information of the supercapacitor, and the output terminal of the judgment control module is connected to the input terminal of the main circuit.

2. The vehicle hybrid electric power distribution system according to claim 1, characterized in that, The fourth input terminal of the control module is used to collect the battery voltage Ud.

3. A method for distributing electric power in a hybrid vehicle, applied to the hybrid vehicle power distribution system as described in claim 1 or 2, characterized in that, The method for distributing electric power in a hybrid vehicle includes the following steps: Step S1: Obtain the voltage Ubus and current Ibus on the DC bus, obtain the voltage Ud and current Id of the battery, obtain the voltage Uc of the supercapacitor; obtain the power Pbus of the DC bus and the power Pd of the battery. Step S2: The current value Ibus is positively determined by the direction from the DC bus to the vehicle load. It is then determined whether the power Pbus of the DC bus is greater than or equal to 0, and thus whether the vehicle load is using or generating electricity. Step S3: If Pbus≥0, the vehicle load is in a power-consuming state; determine the difference between the voltage Uc of the supercapacitor and the preset voltage Ucm of the supercapacitor; if Uc≥Ucm, close the first switch and open the second switch, and the supercapacitor supplies power to the vehicle load through the DC bus; if Uc<Ucm, determine the difference between the power Pd of the battery and the preset power Pdm of the battery; if Pd≥Pdm, close the second switch and open the first switch, and the battery supplies power to the vehicle load through the DC bus. Step S4: If Pbus < 0, the vehicle load is in the power generation state; the vehicle load prioritizes charging the supercapacitor, and after the supercapacitor is fully charged, it then charges the battery.

4. The method for distributing electric power in a hybrid vehicle according to claim 3, characterized in that, In step S3, when Pd≥Pdm, while closing the second switch and opening the first switch, the third switch is closed. When the battery supplies power to the vehicle load through the DC bus, the supercapacitor charges the battery.

5. The method for distributing electric power in a hybrid vehicle according to claim 3, characterized in that, In step S3, if Pd < Pdm, the first switch and the second switch are disconnected, and the third switch is closed, so that the battery charges the supercapacitor.

6. The method for distributing electric power in a hybrid vehicle according to claim 3, characterized in that, In step S4, if Pbus < 0, determine the difference between the voltage Uc of the supercapacitor and the preset voltage Ucm of the supercapacitor. If Uc < Ucm, close the first switch and open the second and third switches. The vehicle load generates electricity to charge the supercapacitor. If Uc≥Ucm, determine the difference between the battery power Pd and the preset battery power value Pdm. If Pd<Pdm, close the second switch and open the first and third switches. The vehicle load generates electricity to charge the battery. If Pd≥Pdm, open the first, second, and third switches.

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