On-board charger realizing adaptive load power adjustment, control method, and electric vehicle

Abstract

An on-board charger having a load power adaptation function, a control method, and an electric vehicle. The on-board charger (10) comprises a power conversion circuit (11) and a control circuit (13), wherein the power conversion circuit (11) is used for receiving a first direct current and converting the first direct current into a first alternating current, so as to supply power to a load (50); and in response to the current value of the first alternating current being greater than a preset current value, the control circuit (13) is used for controlling the power conversion circuit (11) to reduce the current value of the first alternating current, or in response to the output power of the power conversion circuit (11) being greater than a preset power value during the process of the power conversion circuit (11) outputting the first alternating current, the control circuit (13) is used for controlling the power conversion circuit (11) to reduce the current value of the first alternating current. During the process of the on-board charger (10) supplying power to the outside, the operation power of the load (50) can be reduced when the power of the load (50) is excessively high, and thus the load (50) capacity of the on-board charger (10) can be improved.

Description

On-board charger with adaptive load power adjustment, control method and electric vehicle

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on December 19, 2023, with application number 202311760854.5 and application name “On-board charger, control method and electric vehicle with adaptive load power adjustment”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present application relates to the field of power supply and distribution for electric vehicles, and in particular to an on-board charger with adaptive load power adjustment, a control method, and an electric vehicle. Background Art

[0003] With the continuous development of the electric vehicle industry, bidirectional on-board chargers have been developed. Bidirectional on-board chargers have dual functions: charging and power supply. Bidirectional on-board chargers can receive AC power from AC charging piles and convert it into DC power to charge the power battery. Conversely, they can also convert DC power from the power battery into AC power to power external loads. During the power supply process, if the load's operating power exceeds the preset power value, the on-board charger will stop outputting due to excessive output power or current, seriously affecting the user experience.

[0004] Summary of the Invention

[0005] The present application provides an on-board charger, a control method, and an electric vehicle with an adaptive load power adjustment function, which are used to solve the problem that the on-board charger stops outputting power due to excessive load operating power during the on-board charger's external power supply process.

[0006] In a first aspect, the present application provides an on-board charger with adaptive power adjustment functionality. The on-board charger includes a power conversion circuit and a control circuit. The power conversion circuit is configured to receive a first direct current (DC) and convert the first DC to a first alternating current (AC) to power a load, or to receive a second AC and convert the second AC to a second DC to charge a power battery.

[0007] In response to the current value of the first alternating current being greater than a preset current value, the control circuit is used to control the power conversion circuit to reduce the current value or voltage value of the first alternating current; or, in response to the output power of the power conversion circuit being greater than a preset power value during the process of the power conversion circuit outputting the first alternating current, the control circuit is used to control the power conversion circuit to reduce the current value or voltage value of the first alternating current.

[0008] The on-board charger provided in this application is a bidirectional on-board charger, that is, the on-board charger provided in this application can, on the one hand, receive a second alternating current from an AC charging pile and convert the second alternating current into a second direct current to charge the power battery of the electric vehicle; on the other hand, it can receive a first direct current from the power battery and convert the first direct current into a first alternating current to supply power to the outside.

[0009] During the process of the on-board charger supplying power to the outside, if the power of the load is too large, the output power of the on-board charger will exceed the rated power and the overload will stop outputting, thereby limiting the load power that the on-board charger can drive. The on-board charger provided by the embodiment of the present application can reduce the current value of the first alternating current when the output power is too large. According to Ohm's law U=I*R, during the operation, when the current value of the first alternating current output by the power conversion circuit becomes smaller, the output power of the power conversion circuit (that is, the output power of the on-board charger) is also reduced, and the operating voltage and operating power of the load are also reduced accordingly, thereby avoiding the on-board charger output power or output current exceeding the limit. The voltage at which the load can generally operate normally is a range between the minimum operating voltage and the maximum operating voltage, that is, the load can still operate normally if the voltage of the load is moderately reduced.

[0010] The control circuit of the on-board charger provided in the present application can also directly control the power conversion circuit to reduce the voltage value of the first alternating current when the current value of the first alternating current output by the power conversion circuit is too large or the output power is too large, thereby also achieving the above-mentioned technical effect.

[0011] The preset current value can be the rated current value of the on-board charger, or a current value determined based on the output current limit of the on-board charger, for example, 1.1 times or 0.9 times the rated current value. Of course, it can also be a current value determined based on the actual operating requirements of the on-board charger. Similarly, the preset power value can be the rated output power of the on-board charger, or a power value determined based on the output power limit of the on-board charger, or of course, a power value determined based on the actual operating requirements of the on-board charger.

[0012] In summary, the on-board charger provided by this application can adaptively adjust the output power during the process of powering the vehicle, thereby avoiding the on-board charger's difficulty in operation due to the output power or output current exceeding the limit, thereby improving the operational reliability of the on-board charger. On the other hand, the on-board charger provided by this application can increase the load capacity when powering the vehicle, thereby improving the on-board charger's external power supply capability.

[0013] In an implementation of the first aspect, when the control circuit is used to control the power conversion circuit to reduce the current value of the first alternating current, the voltage value of the first alternating current decreases as the current value of the first alternating current decreases.

[0014] In an implementation of the first aspect, when the control circuit is used to control the power conversion circuit to reduce the current value of the first alternating current, the output power of the power conversion circuit decreases as the current value of the first alternating current decreases.

[0015] According to Ohm's law, U = I*R and P = I2*R, where R is the load resistance. During the process of the on-board charger supplying power to the outside, the load resistance remains basically unchanged. When the current value I of the first AC power decreases, the voltage value U of the first AC power and the output power P of the power conversion circuit also decrease.

[0016] In an implementation of the first aspect, during the process of the control circuit controlling the power conversion circuit to reduce the current value of the first alternating current, the control circuit responds to the current value of the first alternating current being less than a preset current value and the voltage value of the first alternating current being less than a preset voltage value, and the control circuit controls the power conversion circuit to increase the voltage value of the first alternating current.

[0017] The preset voltage value here can be the minimum operating voltage of the load, or it can be a voltage value determined by the on-board charger based on actual operating conditions so that the on-board charger can normally power the load so that the load can work normally. After the control circuit is used to reduce the current value of the first alternating current to less than the rated current, if the voltage value of the first alternating current is less than the minimum operating voltage of the load at this time, the load will be difficult to operate due to the low voltage. At this time, the control circuit can be further used to increase the voltage value of the first alternating current to enable the load to work.

[0018] In an implementation of the first aspect, in the process of controlling the power conversion circuit to reduce the current value of the first alternating current, the control circuit responds to the current value of the first alternating current being greater than or equal to a preset current value and the voltage value of the first alternating current being less than or equal to a preset voltage value, and the control circuit is used to control the power conversion circuit to stop outputting the first alternating current.

[0019] After the control circuit is used to reduce the current value of the first AC power, if the voltage value of the first AC power is less than the minimum operating voltage value of the load and the current value of the first AC power is still greater than the preset current value, if the voltage value of the first AC power is increased, the current value of the first AC power will further increase, thereby causing the output current of the on-board charger to exceed the limit. If the voltage value of the first AC power is not increased, the load will have difficulty operating. In this case, it indicates that the power of the load has exceeded the output limit of the on-board charger. The control circuit is used to control the power conversion circuit to stop outputting the first AC power to ensure the safety of the on-board charger.

[0020] In one implementation of the first aspect, during the process of the power circuit outputting the first alternating current, the control circuit is configured to control the output power of the power conversion circuit to be equal to the rated power of the load in response to the rated power of the load being less than or equal to a preset power value. In response to the rated power of the load being greater than the preset power value, the control circuit is configured to control the power conversion circuit to reduce the voltage or current of the first alternating current until the actual power of the load is less than or equal to the preset power value.

[0021] The on-board charger provided in this application can control the output power of the power conversion circuit based on a comparison between the rated power of the load and the rated power of the on-board charger. If the rated power of the load is less than or equal to a preset power value, that is, the rated power of the load is less than the output power limit of the on-board charger, the control circuit can control the output power of the power conversion circuit to be equal to the rated power of the load. If the rated power of the load is greater than the preset power value, in order to ensure the normal operation of the on-board charger, the control circuit is used to control the power conversion circuit to reduce the voltage or current of the first alternating current until the actual power of the load is less than or equal to the preset power value.

[0022] In an implementation of the first aspect, during the process of the power circuit being used to output a first alternating current, the control circuit responds to the output power of the power conversion circuit increasing from less than or equal to a preset power value to greater than the preset power value, and the control circuit is used to control the power conversion circuit to reduce the current value of the first alternating current until the output power of the power conversion circuit is less than or equal to the preset power value.

[0023] In an implementation of the first aspect, during the process of the power conversion circuit being used to output the first alternating current, the control circuit responds to the output voltage of the power battery being less than a second preset voltage value, and the control circuit controls the current value of the first alternating current output by the power conversion circuit to be less than a second preset current value.

[0024] The second preset voltage value herein refers to the voltage value corresponding to a low remaining charge of the power battery. For example, the second preset voltage value may be the power battery output voltage corresponding to a power battery SOC of 20%. The second preset current value refers to the current value that can support normal operation of the load. For example, the second preset current value may be the current value corresponding to the load operating at the rated voltage, or may be a current value determined based on the actual operating conditions of the on-board charger. The on-board charger provided in this application can limit the output current value of the power conversion circuit when the remaining charge of the power battery is low, thereby reducing the output power of the power conversion circuit and thereby reducing the rate of power battery energy consumption, conserving power battery energy, and improving the vehicle's overall range.

[0025] In one implementation of the first aspect, the power conversion circuit includes a power factor correction circuit and a bidirectional DC conversion circuit. The bidirectional DC conversion circuit is configured to receive a first DC power and adjust a voltage of the first DC power, and the power factor correction circuit is configured to convert the DC power from the bidirectional DC conversion circuit into a first AC power.

[0026] In an implementation of the first aspect, the on-board charger includes a second DC conversion circuit, which is used to convert the first DC power into a third DC power, where a voltage of the third DC power is lower than a voltage of the second DC power.

[0027] In a second aspect, the present application provides a load power adaptive control method for an on-board charger, wherein the on-board charger includes a power conversion circuit configured to receive a first direct current (DC) and convert the first DC into a first alternating current (AC) to power a load. The control method includes:

[0028] In response to the current value of the first alternating current being greater than a preset current value, controlling the power conversion circuit to reduce the current value or voltage value of the first alternating current; or,

[0029] In response to the output power of the power conversion circuit being greater than a preset power value during the process of the power conversion circuit outputting the first alternating current, the power conversion circuit is controlled to reduce the current value or voltage value of the first alternating current.

[0030] In an implementation of the second aspect, the control method includes:

[0031] In the process of controlling the power conversion circuit to reduce the current value of the first alternating current, in response to the current value of the first alternating current being less than a preset current value and the voltage value of the first alternating current being less than a preset voltage value, the power conversion circuit is controlled to increase the voltage value of the first alternating current.

[0032] In an implementation of the second aspect, the control method includes:

[0033] In the process of controlling the power conversion circuit to reduce the current value of the first alternating current, in response to the current value of the first alternating current being greater than or equal to a preset current value and the voltage value of the first alternating current being less than or equal to a preset voltage value, the power conversion circuit is controlled to stop outputting the first alternating current.

[0034] The beneficial effects of the control method provided in this application are similar to the beneficial effects of the on-board charger provided in the first aspect of this application, and will not be repeated here.

[0035] In a third aspect, the present application provides an electric vehicle, comprising an onboard charger as described in any one of the first aspects, a power battery, and a low-voltage load. The onboard charger is configured to receive a first direct current from the power battery and output a first alternating current and a third direct current, the third direct current being used to power the low-voltage load.

[0036] The beneficial effects of the electric vehicle provided in this application are the same as the beneficial effects of the on-board charger provided in the first aspect of this application, and will not be repeated here. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments of the present application will be described below.

[0038] FIG1 is a schematic structural diagram of an electric vehicle provided in an embodiment of the present application;

[0039] FIG2 is a schematic structural diagram of a vehicle-mounted charger provided in an embodiment of the present application;

[0040] FIG3 is a schematic structural diagram of another on-board charger provided in an embodiment of the present application;

[0041] FIG4 is a schematic structural diagram of another on-board charger provided in an embodiment of the present application;

[0042] Figures 5a and 5b are circuit diagrams of a vehicle-mounted charger provided in an embodiment of the present application;

[0043] FIG6 is a circuit diagram of another on-board charger provided in an embodiment of the present application;

[0044] FIG7 is a schematic diagram of the operation of an on-board charger;

[0045] FIG8 is a load parameter diagram provided in an embodiment of the present application;

[0046] FIG9 is a schematic diagram of the operation of another on-board charger provided in an embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to better understand the technical solution of the present application, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0048] It should be clear that the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0049] The terms used in the embodiments of the present application are for the purpose of describing specific embodiments only and are not intended to limit the present application. The singular forms "a", "an", "the" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise.

[0050] It should be understood that the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0051] It should be understood that in this application, "at least one (item)" means one or more, and "plurality" means two or more. "And / or" is used to describe the association relationship of associated objects, indicating that three relationships may exist. For example, "A and / or B" can mean: only A exists, only B exists, and A and B exist at the same time, where A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following items" or similar expressions refers to any combination of these items, including any combination of single items or plural items. For example, at least one of a, b or c can mean: a, b, c, "a and b", "a and c", "b and c", or "a and b and c", where a, b, c can be single or multiple.

[0052] The charging problem of electric vehicle power batteries is a key issue that determines the performance and user experience of electric vehicles. Currently, the methods of charging electric vehicle power batteries mainly include fast charging and slow charging. Among them, fast charging refers to the direct charging of the power battery by a DC charging pile. Slow charging refers to the direct connection of alternating current (AC) to the electric vehicle, and the conversion of AC to DC is carried out through an on-board charger (OBC) before charging the power battery. Specifically, the on-board charger is provided with a power factor correction (PFC) circuit and a DC conversion circuit. After the power factor correction circuit converts the connected AC power into DC power, the DC conversion circuit converts the DC power from the power factor correction circuit into high-voltage DC power to charge the power battery.

[0053] When using electric vehicles, users often encounter situations where the vehicle's power battery needs to be discharged. For example, when users are camping, they may use various loads such as kettles, ovens, and stereos. A bidirectional on-board charger can meet this need. In addition to converting AC power from an AC charging station into DC power to charge the power battery, a bidirectional on-board charger can also receive power from the power battery and convert the DC output of the power battery into AC power for external power supply.

[0054] However, if the load power is too large during the on-board charger's power supply, the on-board charger's output power will exceed the rated power and become overloaded. The on-board charger will then stop outputting power due to the overload, limiting the load power it can drive and affecting the user experience. To address this issue, the present application provides an on-board charger with adaptive load capacity and an electric vehicle.

[0055] Please refer to Figure 1, which is a structural schematic diagram of an electric vehicle 01 provided in an embodiment of the present application. The electric vehicle 01 includes at least an on-board charger 10 and a power battery 30. When the on-board charger 10 is used to charge the power battery 30, the on-board charger 10 is connected to the AC charging pile 40, and the on-board charger 10 converts the second AC power from the AC charging pile 40 into a second DC power to charge the power battery 30. When the on-board charger 10 is used to supply power to the outside, the on-board charger 10 is used to connect to a load 50 outside the vehicle, and the on-board charger 10 is used to convert the first DC power from the power battery 30 into a first AC power for output and then power the load 50.

[0056] Figure 2 is a schematic diagram of the structure of an on-board charger 10. The on-board charger 10 includes a power conversion circuit 11 and an insulating housing 12. The power conversion circuit 11 is housed in the insulating housing 12. The power conversion circuit 11 includes a power factor correction circuit 111 and a bidirectional DC conversion circuit 112. The insulating housing 12 includes a power battery interface 122 and a power supply interface 121.

[0057] When the onboard charger 10 is used to charge the power battery 30, the power supply interface 121 is used to connect to the charging gun of the AC charging station 40, and the power battery interface 122 is used to connect to the power battery 30 of the electric vehicle 01. The power factor correction circuit 111 is now operating in rectification mode, converting the second AC power from the AC charging station 40 into DC power. The bidirectional DC conversion circuit 112 adjusts the voltage of the DC power output by the power factor correction circuit 111 and then outputs the second DC power to charge the power battery 30.

[0058] When the on-board charger 10 is used to supply power externally, the power supply interface 121 is used to connect to the load 50, the power battery interface 122 is used to connect to the power battery 30, and the bidirectional DC conversion circuit 112 is used to adjust the voltage of the first DC power from the power battery 30. The power factor correction circuit 111 operates in the inverter mode at this time. The power factor correction circuit 111 is used to convert the DC power output by the DC conversion circuit into a first AC power, and the first AC power is used to power the load 50.

[0059] Figure 2 is a schematic diagram of the onboard charger 10 according to an embodiment of the present application converting the second AC power from the AC charging station 40 into the second DC power to charge the power battery 30. Figure 3 is a schematic diagram of the onboard charger 10 according to an embodiment of the present application converting the first DC power from the power battery 30 into the first AC power to power the load 50.

[0060] In one embodiment, as shown in Figure 4, the onboard charger 10 can also be used to power low-voltage loads 60 in the electric vehicle 01. The power conversion circuit 11 includes a second DC conversion circuit 113, which is configured to receive the first DC power outputted by the bidirectional DC conversion circuit 112 and convert it into a third DC power whose voltage is lower than that of the first DC power. This third DC power is used to power the low-voltage loads 50 in the electric vehicle 01. These low-voltage loads 50 include a low-voltage battery and other low-voltage electrical appliances, such as windshield wipers and an air conditioning compressor.

[0061] As shown in FIG. 2 to FIG. 4 , the on-board charger 10 provided in the embodiment of the present application further includes a control circuit 13 , which is used to control the operation of the power conversion circuit 11 .

[0062] Figures 5a and 5b are schematic diagrams of the circuit structure of the power conversion circuit 11 provided in an embodiment of the present application. The power factor correction circuit 111 is used to perform AC-DC conversion. The bidirectional DC conversion circuit 112 is used to perform DC-DC conversion to change the voltage of DC power. As shown in Figure 5a, the bidirectional DC conversion circuit 112 includes a primary power circuit 1121, a transformer 1122, and a secondary power circuit 1123. When the on-board charger 10 is used to supply power to the outside, the secondary power circuit 1123 of the bidirectional DC conversion circuit 112 transfers electrical energy to the primary power circuit 1121 through the transformer 1122. When the on-board charger 10 is used to charge the power battery 30, the primary power circuit 1121 of the bidirectional DC conversion circuit 112 transfers electrical energy to the secondary power circuit 1123 through the transformer 1122.

[0063] Figure 5b is a schematic diagram of a specific circuit structure of a power factor correction circuit 111. The working modes of the power factor correction circuit 111 include a rectification mode and an inversion mode. When the power factor correction circuit 111 operates in the rectification mode, the power factor correction circuit 111 is used to convert AC power into DC power. Specifically, the power factor correction circuit 111 is used to convert the second AC power from the AC charging pile into DC power. The bidirectional DC conversion circuit 112 is used to change the voltage of the DC power output from the power factor correction circuit 111 and ultimately output the second DC power to charge the power battery 30. When the power factor correction circuit 111 operates in the rectification mode, the power factor correction circuit 111 is used to convert AC power into DC power. Specifically, the bidirectional DC conversion circuit 112 receives the first DC power output from the power battery 30 and reduces the voltage of the first DC power. The power factor correction circuit 111 receives the DC power from the bidirectional DC conversion circuit 112 and converts it into the first AC power to power the load 50.

[0064] FIG6 is a schematic diagram of another on-board charger 10 provided in an embodiment of the present application. As shown in FIG6 , the on-board charger 10 further includes a second DC conversion circuit 113. The second DC conversion circuit 113 is used to convert the second DC power output by the power battery 30 into a third DC power. The voltage of the third DC power is lower than that of the second DC power, and the third DC power is used to power the low-voltage load 50 on the electric vehicle 01. In one embodiment, the second power circuit can also receive the first DC power from the bidirectional DC conversion circuit 112 and convert the first DC power into the third DC power to power the low-voltage load 60 on the electric vehicle 01.

[0065] The onboard charger 10 shown in FIG6 is a two-in-one design combining an onboard charger 10 and an onboard DC-DC converter. In other words, the onboard charger 10 shown in FIG6 integrates both the onboard charger 10 and the onboard DC-DC converter. The onboard charger 10 shown in FIG6 can charge the power battery 30, power low-voltage electrical appliances in the electric vehicle 01, or charge the low-voltage battery.

[0066] It should be noted that when the on-board charger 10 provided in this application is supplying power to the outside, the output power of the on-board charger 10 is the output power of the power conversion circuit 11, and the output power of the power conversion circuit 11 is the power of the first alternating current output by the power conversion circuit 11. The output current of the on-board charger 10 is the current value of the first alternating current output by the power conversion circuit 11. The rated power of the on-board charger 10 is the power limit that the on-board charger 10 can normally output. In other words, the output power of the on-board charger 10 cannot exceed the rated power for a long time. The rated current of the on-board charger 10 is the current limit that the on-board charger 10 can normally output. In other words, the output current of the on-board charger 10 cannot exceed the rated current for a long time.

[0067] When the on-board charger 10 is supplying power to an external device, if the power of the electrical appliance is too high, the output power of the on-board charger 10 will exceed the rated power, causing an overload. The on-board charger 10 will stop outputting power due to the overload, thereby limiting the load 50 power that the on-board charger 10 can drive. However, the on-board charger 10 provided in the embodiment of the present application can adaptively adjust the output voltage or current when the output power is too high, thereby improving the load 50 power capacity of the on-board charger 10. The specific process of the on-board charger 10 adaptively adjusting the output voltage and output current to improve the load 50 power capacity of the on-board charger 10 is described below with reference to specific embodiments.

[0068] Figure 7 is a schematic diagram of the power conversion circuit 11 outputting the first alternating current. As shown in Figure 7, during the period 0-t0, the current of the first alternating current is less than the rated output current of the onboard charger 10, the voltage of the first alternating current is equal to the rated voltage of the load 50 (e.g., 220V), and the output power of the power conversion circuit 11 is less than the rated output power of the onboard charger 10. At time t0, the operating power of the load 50 increases, and the output power of the power conversion circuit 11 increases, exceeding the rated output power. Therefore, after time t0, the current of the first alternating current exceeds the rated current, and the power of the first alternating current exceeds the rated power. This can cause the onboard charger 10 to overload and cease output. Furthermore, the excessive output current and power can damage the power components of the onboard charger 10, thereby affecting the safe and reliable operation of the onboard charger 10.

[0069] The on-board charger 10 provided in the embodiment of the present application has an adaptive load 50 power regulation function. Specifically, the control circuit 13 responds to the current value of the first alternating current being greater than the preset current value of the on-board charger 10, and the control circuit 13 is used to control the power conversion circuit 11 to reduce the current value or voltage value of the first alternating current. Alternatively, the control circuit 13 responds to the output power of the power conversion circuit 11 being greater than the preset power value of the on-board charger 10 during the process of outputting the first alternating current, and the control circuit 13 is used to control the power conversion circuit 11 to reduce the current value or voltage value of the first alternating current.

[0070] The preset current value can be the rated current value of the on-board charger 10, or a current value determined based on the output current limit of the on-board charger 10, for example, 1.1 times or 0.9 times the rated current value. Of course, it can also be a current value determined based on the actual operating requirements of the on-board charger 10. Similarly, the preset power value can be the rated output power of the on-board charger, or a power value determined based on the output power limit of the on-board charger 10, or of course, a power value determined based on the actual operating requirements of the on-board charger 10.

[0071] The on-board charger 10 provided in this application is a bidirectional on-board charger 10. That is, the on-board charger 10 provided in this application can, on the one hand, receive the second alternating current from the AC charging pile 40 and convert the second alternating current into a second direct current to charge the power battery 30 of the electric vehicle 01. On the other hand, it can receive the first direct current from the power battery 30 and convert the first direct current into a first alternating current to supply power externally. During the process of the on-board charger 10 supplying power externally, if the power of the load 50 is too large, the output power of the on-board charger 10 will exceed the rated power and the overload will stop output, thereby limiting the power of the load 50 that the on-board charger 10 can drive. The on-board charger 10 provided in the embodiment of the application can reduce the current value of the first alternating current when the output power is too large. According to Ohm's law U = I * R, since during operation, when the current value of the first alternating current output by the power conversion circuit 11 decreases, the operating voltage and operating power of the load 50 also decrease, thereby reducing the output power of the on-board charger 10, avoiding the on-board charger 10 output power or output current exceeding the limit. The voltage range in which the load 50 can operate normally is generally between the minimum operating voltage and the maximum operating voltage. That is, during the operation of the load 50, the voltage of the load 50 can be appropriately reduced and the load 50 can still operate normally. In summary, the on-board charger 10 provided in the present application can adaptively adjust the output power during the external power supply process to avoid the on-board charger 10 being difficult to operate due to the output power or output current exceeding the limit, thereby improving the operational reliability of the on-board charger 10. On the other hand, the on-board charger 10 provided in the present application can improve the load 50 capacity when supplying power to the outside, thereby improving the external power supply capacity of the on-board charger 10.

[0072] The control circuit 13 of the on-board charger 10 provided in the present application can also directly control the power conversion circuit to reduce the voltage value of the first alternating current output by the power conversion circuit 11 when the current value of the first alternating current output by the power conversion circuit 11 is too large or the output power is too large, thereby also achieving the above-mentioned technical effect.

[0073] The following describes this process with a specific example.

[0074] For example, the on-board charger 10 provided in the embodiment of the present application has a rated output power of 6 kW, a rated output voltage of 220 V, and a rated current of 27.27 A. Figure 8 shows the rated power, operating voltage range, and rated voltage of common electrical appliances. Assuming that during the time period 0-t0, only the oven and kettle are operating, the output voltage of the on-board charger 10 is 220 V, the output power is 2800 W, and the output current is 12.72 A, then the on-board charger 10 can operate normally. At time t0, assuming that the oven, kettle, barbecue grill, induction cooker, and outdoor air conditioner are all operating, the rated power of the load 50 increases to 8 kW, and the output power of the on-board charger 10 accordingly increases to 8 kW. If the voltage of the first AC power source remains at 220 V, the current of the first AC power source is now 36.36 A. This means that both the output power and output current of the on-board charger 10 exceed the limit, affecting the safe and reliable operation of the on-board charger 10.

[0075] For the on-board charger 10 provided in the embodiment of the present application, when the output power of the on-board charger 10 reaches 8 kW, exceeding the rated output power of the on-board charger 10, the control circuit 13 controls the power conversion circuit 11 to reduce the current value of the first AC power. For example, the control circuit 13 controls the power conversion circuit 11 to reduce the current value of the first AC power to 30 A. The resistance value of the load 50 is 2202 / 8000 = 6.05 ohms. After the current value of the first AC power reaches 30 A, the operating voltage of the load 50 becomes 181.5 V, the operating power of the load 50 becomes 5445 W, and the output power of the on-board charger 10 is also 5445 W. In other words, after the current value of the first AC power drops to 30 A, the output current and output power of the on-board charger 10 both fall below the rated values, and the on-board charger 10 can operate normally. Since 181.5 V is within the operating voltage range of the load 50, the load 50 can still operate normally at this time.

[0076] Figure 9 is a schematic diagram illustrating the process by which the onboard charger 10 adaptively adjusts the power of the load 50 during power supply, according to an embodiment of the present application. As shown in Figure 9 , at time t0, the output power of the onboard charger 10 suddenly increases, and the output current also increases accordingly. Subsequently, the control circuit 13 controls the power conversion circuit 11 to reduce the current of the first AC power. As the current of the first AC power decreases, the voltage of the first AC power and the output power of the power conversion circuit 11 also decrease.

[0077] In one embodiment, in response to the current value of the first alternating current being greater than a preset current value or the output power of the power conversion circuit 11 being greater than a preset power value, the control circuit 13 may also be configured to control the power conversion circuit 11 to directly reduce the voltage value of the first alternating current. The specific process is similar to the process of the control circuit 13 controlling the power conversion circuit 11 to directly reduce the current value of the first alternating current and is not further described here.

[0078] In one embodiment, when the control circuit 13 is used to control the power conversion circuit 11 to reduce the current value of the first alternating current, the voltage value of the first alternating current decreases as the current value of the first alternating current decreases.

[0079] In one embodiment, when the control circuit 13 is used to control the power conversion circuit 11 to reduce the current value of the first alternating current, the output power of the power conversion circuit 11 decreases as the current value of the first alternating current decreases.

[0080] According to Ohm's law, U=I*R and P=I 2 *R, R is the resistance value of the load 50. The resistance value of the load 50 changes slightly during operation. When the current value I of the first alternating current decreases, the voltage value U of the first alternating current and the output power P of the power conversion circuit 11 decrease accordingly.

[0081] In one embodiment, during the process of the control circuit 13 controlling the power conversion circuit 11 to reduce the current value of the first alternating current, the control circuit 13 responds to the current value of the first alternating current being less than the rated output current and the voltage value of the first alternating current being less than a preset voltage value, and the control circuit 13 controls the power conversion circuit 11 to increase the voltage value of the first alternating current.

[0082] After the control circuit 13 is used to reduce the current value of the first alternating current to less than the rated current, if the voltage value of the first alternating current is less than the minimum operating voltage of the load 50 at this time, the load 50 will have difficulty in operating due to the low voltage. At this time, the control circuit 13 can be further used to increase the voltage value of the first alternating current to enable the load 50 to operate.

[0083] The preset voltage value here can be the minimum operating voltage of the load 50, or it can be a voltage value determined by the on-board charger according to the actual operating conditions so that the on-board charger 10 can normally power the load 50 so that the load 50 can operate normally. After the control circuit 13 is used to reduce the current value of the first alternating current to less than the rated current, if the voltage value of the first alternating current is less than the minimum operating voltage of the load at this time, the load 50 will be difficult to operate due to the low voltage. At this time, the control circuit can be further used to increase the voltage value of the first alternating current to enable the load 50 to operate.

[0084] For example, if the on-board charger 10 has a rated output power of 6 kW, a rated output voltage of 220 V, and a rated current of 30 A, and the load 50 has a rated power of 25 kW, then the resistance of the load 50 is 1.936 ohms. At this point, if the output power of the on-board charger 10 is to be reduced to the rated output power, the operating voltage of the load 50 is 107.8 V, which is less than the minimum operating voltage of the load 50. In other words, the on-board charger 10 cannot operate the load 50 normally without exceeding the output power limit. In this case, the control circuit 13 controls the power conversion circuit 11 to stop outputting the first AC power to protect the on-board charger 10.

[0085] In one embodiment, in the process of controlling the power conversion circuit 11 to reduce the current value of the first alternating current, the control circuit 13 responds to the current value of the first alternating current being greater than or equal to the rated output current and the voltage value of the first alternating current being less than or equal to a preset voltage value, and the control circuit 13 is used to control the power conversion circuit 11 to stop outputting the first alternating current.

[0086] After the control circuit 13 is used to reduce the current value of the first AC power, if the voltage value of the first AC power is less than the operating voltage of the load 50 and the current value of the first AC power is still greater than the rated output current of the on-board charger 10, if the voltage value of the first AC power is increased, the current value of the first AC power will be further increased, thereby causing the output current of the on-board charger 10 to exceed the limit. If the voltage value of the first AC power is not increased, it will cause the load 50 to have difficulty operating. In this case, it indicates that the power of the load 50 exceeds the output limit of the on-board charger 10. The control circuit 13 is used to control the power conversion circuit 11 to stop outputting the first AC power to ensure the safety of the on-board charger 10.

[0087] In one embodiment, during the process of the power circuit being used to output the first alternating current, the control circuit 13 is configured to control the output power of the power conversion circuit 11 to be equal to the rated power of the load 50 in response to the rated power of the load 50 being less than or equal to the rated output power of the on-board charger 10. In response to the rated power of the load 50 being greater than the rated output power of the on-board charger 10, the control circuit 13 is configured to control the power conversion circuit 11 to reduce the voltage of the first alternating current until the actual power of the load 50 is less than or equal to the rated output power of the on-board charger 10.

[0088] In one embodiment, during the process of the power circuit being used to output the first alternating current, the control circuit 13 responds to the output power of the power conversion circuit 11 increasing from less than or equal to the rated output power of the on-board charger 10 to greater than the rated output power of the on-board charger 10. The control circuit 13 is used to control the power conversion circuit 11 to reduce the current value of the first alternating current until the output power of the power conversion circuit 11 is less than or equal to the rated output power of the on-board charger 10.

[0089] In one embodiment, when the power conversion circuit 11 is used to output the first alternating current, the control circuit 13 responds to the output voltage of the power battery 30 being less than the second preset voltage value, and the control circuit 13 is used to control the current value of the first alternating current output by the power conversion circuit 11 to be less than the second preset current value.

[0090] The second preset voltage value here refers to the voltage value corresponding to when the remaining power of the power battery 30 is small. For example, the second preset voltage value can be the power battery output voltage corresponding to when the SOC of the power battery is 20%, and the second preset current value refers to the current value that can support the normal operation of the load. For example, the second preset current value can be the current value corresponding to when the load is operating at the rated voltage, or it can be a current value determined based on the actual operating conditions of the on-board charger. The on-board charger 10 provided in this application can limit the output current value of the power conversion circuit 11 when the remaining power of the power battery 30 is small, reduce the output power of the power conversion circuit 11, thereby reducing the consumption rate of the power battery's electrical energy, saving the energy of the power battery 30, and improving the vehicle's endurance.

[0091] In one embodiment, during the process of the power conversion circuit 11 being used to output the first alternating current, the control circuit 13 responds to the battery state of charge of the power battery 30 being less than a preset battery state of charge, and the control circuit 13 is used to control the current value of the first alternating current output by the power conversion circuit 11 to be less than a preset current.

[0092] When the onboard charger 10 is supplying power, the energy source is the power battery 30 of the electric vehicle 01. If the output voltage of the power battery 30 is low or the battery state of charge is low, it indicates that the remaining power of the power battery 30 is low. In this case, to conserve the power of the power battery 30, the onboard charger 10 will actively reduce the output current and thus the output power to reduce energy consumption.

[0093] For example, the rated output power of the onboard charger 10 is 6 kW, the rated output voltage is 220 V, and the rated current is 30 A. If the battery state of charge of the power battery 30 is less than or equal to 0.3, the output current of the onboard charger 10 is limited to less than or equal to 20 A, provided that the load 50 can operate normally.

[0094] Based on the above-mentioned on-board charger 10, the embodiment of the present application further provides a control method for the on-board charger 10 with an adaptive load 50 power regulation function. The control method includes:

[0095] In response to the current value of the first alternating current being greater than a preset current value, controlling the power conversion circuit 11 to reduce the current value or voltage value of the first alternating current; or,

[0096] In response to the output power of the power conversion circuit 11 being greater than a preset power value during the process of the power conversion circuit 11 outputting the first alternating current, the power conversion circuit 11 is controlled to reduce the current value or voltage value of the first alternating current.

[0097] The control method for an on-board charger 10 with adaptive load 50 power regulation provided in an embodiment of the present application can adaptively adjust the output power during the on-board charger 10's external power supply process, thereby preventing the on-board charger 10 from operating uncomfortably due to exceeding the output power or output current limit, thereby improving the operational reliability of the on-board charger 10. Furthermore, the control method provided in this application can improve the load 50 capability during external power supply, thereby improving the on-board charger 10's external power supply capability.

[0098] In one embodiment, the control method includes:

[0099] In the process of controlling the power conversion circuit 11 to reduce the current value of the first alternating current, in response to the current value of the first alternating current being less than the preset current value and the preset voltage value of the first alternating current, the power conversion circuit 11 is controlled to increase the voltage value of the first alternating current.

[0100] After the control circuit 13 is used to reduce the current value of the first alternating current to less than the rated current, if the voltage value of the first alternating current is less than the minimum operating voltage of the load 50 at this time, the load 50 will have difficulty in operating due to the low voltage. At this time, the control circuit 13 can be further used to increase the voltage value of the first alternating current to enable the load 50 to operate.

[0101] In one embodiment, the control method includes:

[0102] In the process of controlling the power conversion circuit 11 to reduce the current value of the first alternating current, in response to the current value of the first alternating current being greater than or equal to the preset current value and the voltage value of the first alternating current being less than or equal to the preset voltage value, the power conversion circuit 11 is controlled to stop outputting the first alternating current.

[0103] After reducing the current value of the first AC power, if the voltage value of the first AC power is less than the operating voltage of the load 50 and the current value of the first AC power is still greater than the rated output current of the on-board charger 10, if the voltage value of the first AC power is increased, the current value of the first AC power will be further increased, thereby causing the output current of the on-board charger 10 to exceed the limit. If the voltage value of the first AC power is not increased, it will cause the load 50 to have difficulty operating. In this case, it indicates that the power of the load 50 exceeds the output limit of the on-board charger 10. In this case, the control method provided in the implementation of this application will control the power conversion circuit 11 to stop outputting the first AC power to ensure the safety of the on-board charger 10.

[0104] Those skilled in the art will understand that the various numerical numbers such as first and second involved in this application are only for the convenience of description and are not used to limit the scope of the embodiments of this application. The sequence and execution order of each process should be determined by its function and internal logic.

[0105] Those skilled in the art will appreciate that the modules of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

Claims

1. A vehicle-mounted charger, characterized in that: The on-board charger includes a power conversion circuit and a control circuit, wherein: The power conversion circuit is used to receive a first direct current and convert the first direct current into a first alternating current to power a load; The control circuit is used for: In response to the current value of the first alternating current being greater than a preset current value, controlling the power conversion circuit to reduce the current value or voltage value of the first alternating current; or, In response to the output power of the power conversion circuit being greater than a preset power value during the process of the power conversion circuit outputting the first alternating current, the power conversion circuit is controlled to reduce a current value or a voltage value of the first alternating current.

2. The vehicle-mounted charger according to claim 1, characterized in that: In the process where the control circuit is used to control the power conversion circuit to reduce the current value of the first alternating current, the voltage value of the first alternating current decreases as the current value of the first alternating current decreases.

3. The vehicle-mounted charger according to claim 1, characterized in that: In the process where the control circuit is used to control the power conversion circuit to reduce the current value of the first alternating current, the output power of the power conversion circuit decreases as the current value of the first alternating current decreases.

4. The vehicle-mounted charger according to claim 1, characterized in that: In the process of controlling the power conversion circuit to reduce the current value of the first alternating current, the control circuit is used to: In response to the current value of the first alternating current being less than the preset current value and the voltage value of the first alternating current being less than a preset voltage value, the power conversion circuit is controlled to increase the voltage value of the first alternating current.

5. The vehicle-mounted charger according to claim 4, characterized in that: In the process of controlling the power conversion circuit to reduce the current value of the first alternating current, the control circuit is used to: In response to the current value of the first alternating current being greater than or equal to the preset current value and the voltage value of the first alternating current being less than or equal to the preset voltage value, the power conversion circuit is controlled to stop outputting the first alternating current.

6. The vehicle-mounted charger according to claim 1, characterized in that: In the process where the power circuit is used to output the first alternating current, the control circuit is used to: In response to the rated power of the load being less than or equal to the preset power value, controlling the output power of the power conversion circuit to be equal to the rated power of the load; In response to the rated power of the load being greater than the preset power value, the power conversion circuit is controlled to reduce the voltage value of the first alternating current until the actual power of the load is less than or equal to the preset power value.

7. The vehicle-mounted charger according to claim 1, characterized in that: In the process where the power circuit is used to output the first alternating current, the control circuit is used to: In response to the output power of the power conversion circuit increasing from less than or equal to the preset power value to greater than the preset power value, the power conversion circuit is controlled to reduce the current value of the first alternating current until the output power of the power conversion circuit is less than or equal to the preset power value.

8. The vehicle-mounted charger according to claim 1, characterized in that: In the process where the power conversion circuit is used to output the first alternating current, the control circuit is used to: In response to the output voltage of the power battery being less than a second preset voltage value, the current value of the first alternating current output by the power conversion circuit is controlled to be less than a second preset current value.

9. The vehicle-mounted charger according to claim 1, characterized in that: The power conversion circuit is used to receive a second alternating current and convert the second alternating current into a second direct current to charge the power battery.

10. The vehicle-mounted charger according to claim 1, characterized in that: The power conversion circuit includes a power factor correction circuit and a bidirectional DC conversion circuit, wherein: The bidirectional DC conversion circuit is used to receive the first DC power and to adjust the voltage of the first DC power, and the power factor correction circuit is used to convert the DC power from the bidirectional DC conversion circuit into the first AC power.

11. The vehicle-mounted charger according to claim 1, characterized in that: The on-board charger includes a second DC conversion circuit, which is used to convert the first DC power into a third DC power, and the voltage of the third DC power is lower than the voltage of the second DC power.

12. A load power adaptive control method for an on-board charger, the on-board charger comprising a power conversion circuit, the power conversion circuit being used to receive a first direct current and convert the first direct current into a first alternating current to power a load, characterized in that: The control method comprises: In response to the current value of the first alternating current being greater than a preset current value, controlling the power conversion circuit to reduce the current value of the first alternating current Current or voltage value; or, In response to the output power of the power conversion circuit being greater than a preset power value during the process of the power conversion circuit outputting the first alternating current, the power conversion circuit is controlled to reduce a current value or a voltage value of the first alternating current.

13. The control method according to claim 12, characterized in that: The control method comprises: In the process of controlling the power conversion circuit to reduce the current value of the first alternating current, in response to the current value of the first alternating current being less than the preset current value and the voltage value of the first alternating current being less than the preset voltage value, the power conversion circuit is controlled to increase the voltage value of the first alternating current.

14. The control method according to claim 13, characterized in that: The control method comprises: In the process of controlling the power conversion circuit to reduce the current value of the first alternating current, in response to the current value of the first alternating current being greater than or equal to the preset current value and the voltage value of the first alternating current being less than or equal to the preset voltage value, the power conversion circuit is controlled to stop outputting the first alternating current.

15. An electric vehicle, characterized in that: The electric vehicle comprises the on-board charger, a power battery and a low-voltage load as claimed in claim 11, wherein: The on-board charger is used to receive the first direct current from the power battery and output the first alternating current and a third direct current, and the third direct current is used to power the low-voltage load.

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