Vehicle-mounted charger operation mode switching control method, device, and vehicle-mounted charger

Abstract

The present application relates to the technical field of on-board charging, and provides an on-board charger operation mode switching control method, device, and on-board charger, the on-board charger operation mode switching control method including the steps of: acquiring an on-board charger operation mode switching signal, the operation mode switching signal including a switching signal for switching from controlling the DC bus voltage by an original power supply module among different power supply modules of the on-board charger to controlling the DC bus voltage by a power supply module to be started; first starting up the power supply module to be started in a current source control mode based on the on-board charger operation mode switching signal, and controlling the power supply module to be started to adjust a given current value according to the operating situation until it bears the system required power; and controlling the control mode of the power supply module to be started to switch to a voltage source control mode, thereby controlling the DC bus voltage. In the present invention, when the on-board charger switches the operation mode, interruption of power supply at the low voltage end is avoided while ensuring the stability of the DC bus voltage.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on November 15, 2021, bearing application number 202111369350.1 and entitled "Method and device for controlling switching between operating modes of an on-board charger and an on-board charger," the entire contents of which are incorporated herein by reference. [Technical Field]

[0002] The present application relates to the field of on-board charging technology, and in particular to an on-board charger operation mode switching control method, device, and on-board charger. [Background technology]

[0003] An on-board charger system is an on-board electrical energy router. Currently, more common on-board chargers can transmit electrical energy from the AC end to the DC bus to the high-voltage battery, convert the electrical energy from the high-voltage battery back to the AC end via the DC bus, or power the on-board low-voltage appliances via the DC bus. These chargers have multiple operating modes. Switching between operating modes affects the DC bus voltage and may require switching the power module. To avoid the voltage and current shocks caused by direct switching, the typical control strategy is to first shut down the on-board charger and then restart it in the new operating mode. However, this method takes a long time and causes a short-term power outage at the low-voltage power end, affecting normal user operation. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present application is to avoid interruption of power supply at the low voltage end while ensuring stability of the DC bus voltage when an on-board charger switches between operation modes. [Means for solving the problem]

[0005] In order to solve the above problems, the present invention provides an on-board charger operation mode switching control method, a step of acquiring an operation mode switching signal of the on-board charger, the operation mode switching signal including a switching signal for switching from controlling the voltage of a DC bus by an original power supply module among different power supply modules of the on-board charger to controlling the voltage of the DC bus by a power supply module to be activated; a step of starting the power supply module to be started in a current source control mode based on the operation mode switching signal, and controlling the power supply module to adjust a given current value according to an operation state until the power required by the system is satisfied; and controlling the power supply module to be started so as to switch the control mode of the power supply module to be started to a voltage source control mode, thereby causing the power supply module to be started to control the voltage of the DC bus.

[0006] Optionally, said system power requirement is the total power of the system.

[0007] Optionally, the step of starting the power supply module to be started in a current source control mode and controlling the power supply module to adjust a given current value according to an operating situation until the power supply module can bear the total power of the system includes: The method includes controlling the power supply module to be started up according to a current source control mode, and controlling the given current value to be changed from a first initial current value to a target current value, wherein the first initial current value is determined by the operating state of the power supply module to be started up before switching, and the target current value is determined by the total power of the system and the port voltage of the power supply module to be started up.

[0008] Optionally, the step of determining a first initial current value according to an operating state of the power supply module to be started before switching includes: obtaining the operation state and port current sampling value of the power supply module to be started before switching; and setting the port current sampling value as the first initial current value.

[0009] Optionally, the port current sampling value is an AC end current sampling value or a high end current sampling value of the on-board charger.

[0010] Optionally, the step of controlling the power supply module to be started up to start up according to a current source control mode includes: The power supply module includes a step of switching an operation mode selection switch of the power supply module to be started to a current source control mode, and controlling the power supply module to be started in the current source control mode.

[0011] Optionally, the step of controlling the power supply module to be started up to start up according to a current source control mode, and controlling the given current value to change from a first initial current value to a target current value, comprises: The method includes controlling the power supply module to be started so that the current value changes from the first initial current value to the target current value at a preset rate of change.

[0012] Optionally, the step of controlling the control mode of the power supply module to be started to switch to a voltage source control mode includes: The method includes controlling the power supply module to be started so as to switch its control mode to a bus voltage source control mode.

[0013] Optionally, the step of controlling the control mode of the power supply module to be started to switch to a bus voltage source control mode includes: obtaining a voltage reference value and a voltage feedback value of the power supply module to be started before switching; generating an inductance current reference value or a high voltage current reference value based on the voltage reference value and the voltage feedback value; and controlling the voltage of the DC bus based on the inductance current reference value or the high voltage current reference value.

[0014] Optionally, generating an inductance current reference value or a high voltage current reference value based on the voltage reference value and the voltage feedback value comprises: Prior to switching the power supply module to be started, the method includes a step of collecting the port current sampling values ​​by a current controller of the power supply module to be started, and calculating and obtaining the inductance current reference value or the high-voltage current reference value by a voltage controller of the power supply module to be started based on the voltage reference value, the voltage feedback value, and the port current sampling values.

[0015] Optionally, the step of controlling the power supply module to be started up in a current source control mode includes: acquiring an operating state of the power supply module to be started before switching; If the operating state of the power supply module to be started before switching is the port voltage source control mode, the step of first shutting down the power supply module to be started and then controlling the power supply module to be started to start in the current source control mode is included.

[0016] Optionally, the on-board charger operation mode switching control method includes: Controlling the voltage of the DC bus; The method further includes controlling the shutdown of the original power supply module or controlling the original power supply module to start up in a current source control mode in which the given current value is a second initial current value.

[0017] Compared with the prior art, the present invention receives an operation mode switching signal from the on-board charger to determine that different power supply modules in the on-board charger need to switch between different operation modes. For example, the present invention switches from controlling the DC bus voltage using the power factor correction converter, which is the original power supply module, to controlling the bus voltage using the high-voltage DC converter, which is the power supply module to be started. Based on the operation mode switching signal from the on-board charger, the power supply module to be started is first started in current source control mode. The given current value can be adjusted according to the operating conditions until it can bear the system's required power. This allows the power supply module to gradually bear the system's required power during the startup process and avoids interruptions to power supply at the low-voltage end. The control mode of the power supply module to be started is then switched to voltage source control mode, in which case the power supply module to be started can be used to bear the required power of the entire system and ensure the stability of the DC bus voltage. Meanwhile, the original power supply module can be shut down or switched to current source control mode, in which the second initial current value is approximately zero, thereby ensuring the stability of the DC bus voltage and completing the operation mode switch.

[0018] In a second aspect, the present invention further provides an on-board charger operation mode switching control device, an acquisition unit for acquiring an operation mode switching signal of the on-board charger, the operation mode switching signal including a switching signal for switching from controlling a voltage of a DC bus bar by an original power supply module among different power supply modules of the on-board charger to controlling the voltage of the DC bus bar by a power supply module to be activated; and a processing unit that starts the power supply module to be started in a current source control mode based on the operation mode switching signal, controls the power supply module to adjust a given current value according to the operation status until the power required by the system is borne, controls the control mode of the power supply module to be started to be switched to a voltage source control mode, and causes the power supply module to be started to control the voltage of the DC bus.

[0019] As a result, the vehicle charger operation mode switching control device is used to realize the above-mentioned vehicle charger operation mode switching control method, and therefore has at least all the technical effects of the above-mentioned vehicle charger operation mode switching control method, and will not be repeated here.

[0020] In a third aspect, the present invention further provides an on-board charger, which includes a computer-readable storage medium storing a computer program and a processor, and when the computer program is loaded and executed by the processor, realizes the above-mentioned on-board charger operation mode switching control method.

[0021] Therefore, the technical solution of the on-board charger at least includes the technical solution of the above-mentioned on-board charger operation mode switching control method, and has at least all the technical effects of the above-mentioned on-board charger operation mode switching control method, which will not be described again here.

[0022] In a fourth aspect, the present invention further provides a computer-readable storage medium having a computer program stored therein, which, when loaded and executed by a processor, realizes the above-described vehicle charger operation mode switching control method.

[0023] Therefore, the technical solution of the computer-readable storage medium includes at least the technical solution of the above-mentioned vehicle charger operation mode switching control method, and has at least all the technical effects of the above-mentioned vehicle charger operation mode switching control method, which will not be described again here. [Brief explanation of the drawings]

[0024] In order to more clearly describe the technical solutions in the embodiments of the present application or the prior art, the drawings that need to be used in the description of the embodiments or the prior art are briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings based on these drawings without making any creative efforts. [Figure 1] FIG. 1 is a schematic diagram illustrating the internal structure of a conventional on-board charger. [Figure 2] FIG. 1 is a schematic diagram of a switching procedure for each power supply module in a conventional on-board charger. [Figure 3] 3 is a flowchart of a control method according to an embodiment of the present invention. [Figure 4] FIG. 2 is a schematic diagram of a controller configuration of a power factor correction converter according to an embodiment of the present invention. [Figure 5] 1 is a schematic diagram illustrating a controller configuration of a high-voltage DC converter according to an embodiment of the present invention. [Figure 6] 1 is a schematic diagram illustrating a controller configuration of a low-voltage DC converter according to an embodiment of the present invention. [Figure 7] FIG. 4 is a schematic diagram of a power module switching procedure of a control method according to an embodiment of the present invention; [Figure 8] 1 is a schematic diagram of a system circuit of an on-board charger according to an embodiment of the present invention; DETAILED DESCRIPTION OF THE INVENTION

[0025] In order to make the above-mentioned objects, features and advantages of the present invention clearer, specific embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

[0026] It should be noted that the terms "first," "second," etc. in the present specification, claims, and above-described drawings are intended to distinguish between similar objects without necessarily describing a particular order or priority. It should be understood that the terms so used may be interchanged where appropriate such that the embodiments of the present invention described herein may be practiced in orders other than those illustrated or described herein.

[0027] In the description of the present invention, unless otherwise clearly specified and limited, the terms "installation," "mounting," "connecting," and "connecting" should be understood in a broad sense, and may refer to, for example, a fixed connection, a detachable connection, an integral connection, a mechanical connection, a direct connection, an indirect connection via an intermediate medium, or an internal connection between two elements. Those skilled in the art can understand the specific meanings of the above terms in the present invention according to specific circumstances.

[0028] In the description herein, references to terms such as "an example," "one example," and "one embodiment" mean that the specific features, structures, materials, or characteristics described in that example or embodiment are included in at least one example or embodiment of the present invention. In this specification, general references to the above terms do not necessarily refer to the same example or embodiment. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more examples or embodiments.

[0029] 1 shows a schematic diagram of the internal structure of a three-port on-board charger in the prior art, which has three ports: an AC end, a high-voltage end, and a low-voltage end, and electrical energy can flow between the three ports. It is an on-board power supply system required for new energy vehicles, and typically has functions such as charging the power battery, powering on-board low-voltage appliances, and powering the AC end, and has various operating modes. The on-board charger includes three parts: a PFC (power factor correction converter), an HVDC (high-voltage direct current converter), and an LVDC (low-voltage direct current converter), which are respectively connected to the above three ports, and the circuits of the three parts: PFC, HVDC, and LVDC, share a single DC bus. PFC can rectify AC power to DC power and supply it to the high-voltage and low-voltage ends via a DC bus, and can also convert DC power back to AC power and supply it to AC loads. HVDC can extract electricity from the DC bus and charge the high-voltage end power battery, and can also extract electricity from the high-voltage end high-voltage power battery and supply it to the AC and low-voltage ends via a DC bus. LVDC can extract electricity from the DC bus and supply it to the low-voltage end low-voltage battery and low-voltage electrical appliances, such as air conditioners, pumps, and headlights.

[0030] When the high-voltage end supplies power to the low-voltage end, i.e., when no AC charging station is connected to the AC end, the LVDC end supplies electrical energy from the high-voltage end high-voltage power battery via HVDC and DC bus, and in this case, the bus voltage is controlled by HVDC. When the AC end supplies power to the high-voltage end and low-voltage end, i.e., when an AC charging station is connected to the AC end, the HVDC is converted to charging mode to charge the high-voltage power battery, and the electrical energy required for the LVDC end is supplied from the AC charging station via PFC and DC bus, and in this case, the bus voltage is controlled by PFC. When the operation mode of an on-board charger switches from high-voltage end power supply to AC end power supply, because the converters controlling the bus voltage are different, the entire on-board charger system is usually first turned off and then restarted in the new operation mode to avoid a sudden change in control signal due to direct switching and the resulting system collapse, which results in power supply interruption for low-voltage end electrical appliances during shutdown and restart. Similarly, other changes in operating mode relating to the switching of bus voltage sources will also cause interruptions in the supply of power at the low voltage end.

[0031] 2, the switching process from the conventional AC charging stand supplying power through a power factor correction converter to control the DC bus voltage to the high-voltage power battery supplying power through a high-voltage DC converter to control the DC bus voltage, and the changes in power and bus voltage are shown. In FIG. 2, the horizontal axis represents time, and the vertical axis represents, from bottom to top, the DC bus voltage value (denoted by VBUS), the power value of the low-voltage DC converter (denoted by PLVDC), the power value of the high-voltage DC converter (denoted by PHVDC), and the power factor correction converter (denoted by PPFC). Positive power (e.g., above 0 on the vertical axis) represents power transmitted to the bus, and negative power (e.g., below 0 on the vertical axis) represents power absorbed from the bus. At time t1, the AC charging stand is supplying power through the power factor correction converter. Since the operating mode needs to be switched from the ON-board charger to the high-voltage power battery to the high-voltage DC converter to supply power, the above three converters first perform a shutdown operation, the DC bus voltage is shut down and discharged to zero in the (t1-t2) step, and after the DC bus voltage discharge is completed, the DC bus voltage is again established by the high-voltage DC converter in the (t2-t3) step, the DC bus voltage establishment is completed at the time t3, the low-voltage end re-establishes the output voltage and resumes power supply at the time t4. From this, it can be seen that the operating mode switching scheme of the on-board charger in the prior art refers to the interval (t1-t4), and the low-voltage end electrical appliances are in a power-off state and take a long time.

[0032] To solve the above technical problems, in combination with FIG. 3, an embodiment of the present invention provides an on-board charger operation mode switching control method, which includes the following steps: S1, obtain an operation mode switching signal of the on-board charger, the operation mode switching signal including a switching signal for switching from controlling the DC bus voltage by an original power module among different power modules of the on-board charger to controlling the DC bus voltage by a power module to be activated; S2, according to the operation mode switching signal, start the power supply module to be started in a current source control mode, and control the current to adjust a given value according to the operation situation until the power required by the system is borne; S3: Control the power supply module to be started so that its control mode is switched to a voltage source control mode, and make the power supply module to be started control the voltage of the DC bus.

[0033] The on-board charger has six operating modes, and when switching between two operating modes under different operating conditions, the control device can first obtain an operating mode switching signal for the on-board charger, thereby providing a prerequisite for the subsequent operating mode switching operation of the power module to be started. Then, based on the obtained operating mode switching signal, the control device first controls the power module to be started to start up in current source control mode by flexibly adjusting the given current value according to the actual operating conditions until the system required power is met, and then controls the control mode of the power module to be started up to switch to voltage source control mode, causing the power module to control the DC bus voltage. In other words, the control is switched from controlling the DC bus voltage by the original power module to controlling the DC bus voltage by the power module to be started up, thereby completing the on-board charger operating mode switching operation while ensuring the stability of the DC bus.

[0034] In this embodiment, the on-board charger's operation mode switching signal is received to determine that different power supply modules in the on-board charger need to switch between different operation modes. For example, the on-board charger switches from controlling the DC bus voltage using the power factor correction converter, which is the original power supply module, to controlling the bus voltage using the high-voltage DC converter, which is the power supply module to be started. Based on the on-board charger's operation mode switching signal, the on-board charger first starts up the power supply module to be started in current source control mode, and adjusts the given current value according to the operating conditions until it covers the system's required power. This allows the power supply module to gradually cover the system's required power during the startup process and avoids interruptions to power supply at the low-voltage end. Next, the control mode of the power supply module to be started is switched to voltage source control mode, which allows the power supply module to be started to cover the system's required power while ensuring the stability of the DC bus voltage. Meanwhile, the original power supply module can be, for example, shut down or switched to current source control mode, in which the second initial current value is approximately zero. This completes the operation mode switch while ensuring the DC bus voltage is stable.

[0035] The six operation modes of the on-board charger mentioned in the above embodiment are as follows: In the process of AC charging of a vehicle using an on-board charger, the AC charging station is mainly used to supply power to the high-voltage power battery, the low-voltage end low-voltage battery, and the low-voltage electrical appliances via a power factor correction converter, and the DC bus voltage is controlled by the power factor correction converter. In this case, the DC bus control by the power factor correction converter has three operating modes according to the different directions of the flow of electrical energy. In operation mode 1, the AC charging station uses a power factor correction converter to control the voltage of the DC bus, the high-voltage DC converter extracts electricity from the DC bus to charge the high-voltage end power battery, and the low-voltage DC converter extracts electricity from the DC bus to supply power to low-voltage end low-voltage electrical appliances. Operation mode 2: The AC charging station controls the DC bus voltage using a power factor correction converter, and the high-voltage DC converter extracts electricity from the DC bus to charge the high-voltage end power battery. In other words, in operation mode 2, unlike operation mode 1, the low-voltage DC converter does not operate, and there is no need to supply power to the low-voltage end. Operation mode 3: The AC charging station controls the DC bus voltage using a power factor correction converter, and the low-voltage DC converter extracts electricity from the DC bus and supplies power to low-voltage electrical appliances at the low-voltage end. In other words, in operation mode 3, unlike operation mode 1, the high-voltage DC converter does not operate, and there is no need to charge the power battery at the high-voltage end.

[0036] After AC charging of the vehicle is completed or the vehicle user needs to disconnect the vehicle from the charging station, the high-voltage power battery is used to supply power to the low-voltage end low-voltage battery and the AC end electrical appliances via the high-voltage DC converter, and the DC bus voltage is controlled. In this case, the control of the DC bus by the high-voltage DC converter has three operation modes. Operation mode 4: The high-voltage power battery controls the voltage of the DC bus using the high-voltage DC converter, the power factor correction converter extracts electricity from the DC bus and supplies power to the AC end electrical appliances, and the low-voltage DC converter extracts electricity from the DC bus and supplies power to the low-voltage end low-voltage electrical appliances. Operation mode 5: The high-voltage power battery controls the voltage of the DC bus bar through the high-voltage DC converter, and the power factor correction converter extracts electricity from the DC bus bar to supply power to the AC end of the electrical appliances. In other words, in operation mode 5, unlike operation mode 4, the low-voltage DC converter does not operate, and there is no need to supply power to the low-voltage end. Operation mode 6: The high-voltage power battery controls the voltage of the DC bus using the high-voltage DC converter, and the low-voltage DC converter extracts electricity from the DC bus and supplies power to the low-voltage end low-voltage electrical appliances. In other words, in operation mode 6, unlike operation mode 4, the power factor correction converter does not operate, and there is no need to supply power to the AC end electrical appliances.

[0037] Note that switching between operation modes 1, 2, and 3 and between operation modes 4, 5, and 6 does not involve switching of the system bus voltage source. However, switching between operation modes 1 and 4, 5, and 6, between operation mode 2 and 4, 5, and 6, and between operation mode 3 and 4, 5, and 6 all involves switching of the DC bus voltage source. For example, when switching from operation mode 1 to operation mode 4, the power factor correction converter is generally the original power module, and the high-voltage DC converter is the power module to be started, because AC charging to the vehicle is generally completed or the vehicle user needs to disconnect the vehicle from the charging station.

[0038] For example, when switching from operating mode 1 to operating mode 4, the control device first obtains the operating mode switching signal of the on-board charger to provide a prerequisite for the subsequent switching of the operating mode of the power module to be started. During the switching process, the original power module is a power factor correction converter, and the power module to be started is a high-voltage DC converter. Then, based on the obtained operating mode switching signal, the control device first controls the high-voltage DC converter, which is the power module to be started, to start up in current source control mode by flexibly adjusting the given current value according to the actual operating conditions until the system required power is covered. Next, it controls the control mode of the power module to be started to switch to voltage source control mode, allowing the power module to be started to control the voltage of the DC bus.

[0039] When switching from the above-mentioned operating mode 4 to operating mode 1, the original power supply module is a high-voltage DC converter and the power supply module to be started is a power factor correction converter. Then, based on the acquired operating mode switching signal, the control device first controls the power factor correction converter, which is the power supply module to be started, to start up in a current source control mode by flexibly adjusting the given current value according to the actual operating situation until the system required power is borne, and then controls the control mode of the power supply module to be started to switch to a voltage source control mode, so that the power supply module to be started controls the voltage of the DC bus.

[0040] Combining Figures 1 and 8, the circuit diagram of the on-board charger in Figure 8 is one embodiment of the circuit configuration of the on-board charger in Figure 1. In other words, the specific circuit diagram of the on-board charger in Figure 1 is not limited to the embodiment of the circuit configuration in Figure 8. Below, combining Figure 8, a specific circuit of the on-board charger will be described in detail. The on-board charger includes a power factor correction converter, a high-voltage DC converter, a low-voltage DC converter, and a control device. In Figure 1, PFC refers to the power factor correction converter, HVDC refers to the high-voltage DC converter, and LVDC refers to the low-voltage DC converter. Furthermore, combining Figure 8, the high-voltage DC converter and the low-voltage DC converter share a primary-side full-bridge converter. For example, the high-voltage DC converter includes a primary-side full-bridge converter and a secondary-side full-bridge converter, and the low-voltage DC converter includes a primary-side full-bridge converter and a secondary-side buck converter. This simplifies the internal circuit structure of the on-board charger, effectively saving costs and reducing circuit volume.

[0041] 8, the power factor correction converter, the high-voltage DC converter, and the low-voltage DC converter are electrically connected to a control device, and the control device samples the electrical parameters of the above three converters and the DC bus. When switching the operating mode, for example, from operating mode 1 to operating mode 4, the control device first controls the high-voltage DC converter, which is the power supply module to be started, to start up in current source control mode and adjusts the current to a given value according to the operating situation until it covers the system required power. Then, the control device controls the control mode of the power supply module to start up to switch to voltage source control mode, thereby controlling the voltage of the DC bus. As for the power factor correction converter, which is the original power supply module, the control device can shut down the original power supply module or control it to operate in current source operating mode, in which the current reference value of the original power supply module is approximately zero.

[0042] In one embodiment of the present invention, the system power requirement is the total power of the system.

[0043] By limiting the system required power to the total system power, in other words, by defining the total system power as the overall system load borne by the power supply module whose operation mode has been switched to start, such as the high-voltage DC converter, it is ensured that the power supply module whose operation mode has been switched to start can fully drive and operate the overall system load, ensuring normal vehicle operation. The total system power includes at least the AC end electrical appliances, the low-voltage end low-voltage battery, and low-voltage electrical appliances such as air conditioners and pumps.

[0044] In one embodiment of the present invention, the step of starting the power supply module to be started in a current source control mode and controlling the power supply module to adjust a given current value according to an operating condition until the power supply module can bear the total power of the system includes: The method includes controlling the power supply module to be started up in a current source control mode and changing the given current value from a first initial current value to a target current value, wherein the first initial current value is determined by the operating state of the power supply module to be started up before switching, and the target current value is determined by the total system power and the port voltage of the power supply module to be started up.

[0045] The power supply module to be started is controlled to start up in current source control mode, and the given current value is controlled to change from a first initial current value to a target current value. During the start-up process of the power supply module to be started up in current source control mode, the first initial current value is changed to the target current value until the power supply module to be started, e.g., a high-voltage DC converter, bears the total power of the system. At the same time, the output power of the original power supply module, e.g., a power factor correction converter, becomes almost zero, thereby preparing to switch from controlling the DC bus voltage by the original power supply module in the on-board charger to controlling the DC bus voltage by the power supply module to be started up. In other words, in this case, because the original power supply module, e.g., a power factor correction converter, bears almost no total power of the system, the instantaneous power loss due to the shutdown of the original power supply module is almost zero, and therefore no significant disturbance occurs in the DC bus voltage. For example, if the original power supply module is a high-voltage DC converter and the power supply module to be started is a power factor correction converter, the specific control method can be adaptively adjusted with reference to the above content of this section, and will not be repeated here.

[0046] The change from the first initial current value to the target current value may be a gradual change or a sudden change. When the first initial current value gradually changes to the target current value, the power supply module to be started gradually bears the total power of the system in current source control mode, thereby ensuring stability of each converter control signal and stable operation of all loads during the operating mode switching operation. When the first initial current value suddenly changes to the target current value, the power supply module to be started can bear the total power of the system in a shorter time, shortening the operating mode switching time and improving the operating mode switching efficiency.

[0047] In this embodiment, the control strategies for the above three converters are described below. The power factor correction converter, which is the original power supply module, adopts a voltage / current dual-loop controller as shown in Figure 4, and has two modes: bus voltage source control and AC voltage source control. When the operation direction selection switch is in position 1 and the operation mode selection switch is in position 4, the power factor correction converter operates in bus voltage source control mode; when the operation direction selection switch is in position 2 and the operation mode selection switch is in position 4, the power factor correction converter operates in port voltage source control mode; and when the operation mode selection switch is in position 3, the power factor correction converter operates in current source control mode.

[0048] The high-voltage DC converter, which is the power supply module to be started, employs the voltage / current dual-loop controller shown in Figure 5, and similarly has two modes: bus voltage control and high-voltage end voltage / current control. When the operation direction selection switch is in position 1 and the operation mode selection switch is in position 4, the high-voltage DC converter operates in bus voltage source control mode; when the operation direction selection switch is in position 2 and the operation mode selection switch is in position 4, the high-voltage DC converter operates in port voltage source control mode; and when the operation mode selection switch is in position 3, the high-voltage DC converter operates in current source control mode.

[0049] The LVDC converter employs a voltage / current dual-loop controller as shown in Figure 6. The LVDC voltage controller calculates the output current required to achieve a given low-voltage end output reference voltage based on the low-voltage end low-voltage voltage reference value and feedback value as the reference value for the LVDC current controller. The LVDC current controller then calculates the control signal for the LVDC converter based on the reference value and the low-voltage current feedback value. For example, the low-voltage end current reference value calculated by the LVDC voltage controller is used as the reference value for the current controller. In other words, if the output voltage of the LVDC converter is controlled to 12V, the LVDC voltage controller calculates the current to be output when outputting a voltage of 12V based on the actual low-voltage end voltage feedback value as the low-voltage end current reference value. Both the PFC converter controller and the HVDC converter controller have a running direction selection switch and a voltage source / current source operating mode selection switch, which are both implemented by software.

[0050] 7, before time t1, when the on-board charger is in operation mode 1, the voltage of the DC bus is controlled by the power factor correction converter. The operation direction selection switch of the controller of the power factor correction converter shown in FIG. 4 is at position 1, the control mode selection switch is at position 4, and the high-voltage DC converter outputs electrical energy to the high-voltage power battery. The operation direction selection switch of the controller of the high-voltage DC converter shown in FIG. 5 is at position 2, the control mode selection switch is at position 4, and the low-voltage DC converter is used to control the low-voltage end output voltage.

[0051] At time t1, the high-voltage DC converter is controlled to switch to a current source control mode for startup. In this case, the operating mode selection switch of the high-voltage DC converter is set to position 3. In this case, a first initial current value is a starting value for the high-voltage DC converter to start up and operate in the current source control mode. The first initial current value can be determined according to the operating state of the power supply module to be started up before switching. The target current value is an output current value required for the power supply module to be started up to bear the total power of the system. The target current value can be calculated based on the total power of the system and the port voltage of the power supply module to be started up.

[0052] In the step of t1-t2, the given current value of the power supply module to be started is controlled to change from the first initial current value to the target current value, in which the high-voltage DC converter gradually bears the total power of the system, and the output power of the power factor correction converter gradually decreases.

[0053] At time t2, combining Figures 5 and 7, the operation direction selection switch of the HVDC converter is switched from position 2 to position 1. In this case, the bus voltage reference value is the rated bus voltage value. In this case, the inductance current reference value calculated by the voltage controller of the HVDC converter is approximately equal to the target current value. Therefore, the stable operation of the on-board charger system is not hindered by a sudden change in the control signal due to the control mode switch.

[0054] In one embodiment of the present invention, the step of determining the first initial current value according to the operating state of the power supply module to be started before switching is: obtaining the operation state and port current sampling value of the power supply module to be started before switching; and setting the port current sampling value as the first initial current value.

[0055] In addition, when the power supply module to be started is normally in a port voltage source operating state before switching, direct switching is likely to cause significant changes in the current system load. Therefore, by obtaining the operating state of the power supply module to be started before switching, the first initial current value can be flexibly adjusted before switching the operating mode, ensuring that the DC bus voltage is not significantly affected during the operating mode switching process. Because the power supply module to be started is in a port voltage source operating state before switching, the port current sampling value is set as the first initial current value. In other words, the high-voltage end current sampling value currently collected by the current controller of the power supply module to be started is set as the first initial current value. This ensures that the control signal and DC bus voltage do not significantly fluctuate at the moment of switching of the power supply module to be started.

[0056] In addition, the power supply module to be started sets its control mode selection switch to position 2 before switching (implemented by software), so that the port current sampling value before switching of the power supply module to be started is obtained as the feedback value of the current controller of the power supply module to be started, and the current sampling value is the inductance current sampling value or the high-voltage end current sampling value, and further, the current controller performs calculations such as ratio and integration to finally obtain a control signal in the bus voltage source control mode.

[0057] In one embodiment of the present invention, the port current sampling value is an AC end current sampling value or a high voltage end current sampling value of the on-board charger.

[0058] If the original power supply module is a power factor correction converter, the power supply module to be started is a high-voltage DC converter, in which case the port current sampled value is the high-voltage end current sampled value, and the switching signal of the on-board charger is a switching signal for switching from controlling the DC bus voltage by the power factor correction converter (the original power supply module) to controlling the DC bus voltage by the high-voltage DC converter (the power supply module to be started). If the original power supply module is a high-voltage DC converter, the power supply module to be started is a power factor correction converter, in which case the port current sampled value is the AC end current sampled value, and the switching signal of the on-board charger is a switching signal for switching from controlling the DC bus voltage by the high-voltage DC converter (the original power supply module) to controlling the DC bus voltage by the power factor correction converter (the power supply module to be started). Using the AC end current sampled value or the high-voltage end current sampled value as the port current sampled value allows the power supply module to be started based on the port current sampled value. In other words, the power supply module to be started is not started directly from zero, which not only shortens the operating mode switching time but also avoids large fluctuations in the DC bus voltage.

[0059] In one embodiment of the present invention, the step of acquiring the operating state of the power supply module to be started before switching includes: The step includes setting the first initial current value to zero when the operating state of the power supply module to be started before switching is a stopped state, and setting the currently collected port current sampling value, for example, the high voltage end or AC end current sampling value, as the first initial current value when the operating state of the power supply module to be started before switching is a charging or discharging operating state.

[0060] Furthermore, if the operating state of the power module to be started before switching is a stopped state, the power module to be started will start up with zero as the first initial current value, gradually shouldering the system power borne by the original power module, ensuring a more stable voltage during startup and avoiding fluctuations in the DC bus voltage.If the operating state of the power module to be started before switching is a charging state, the AC end current sampling value will be the first initial current value, or if the operating state of the power module to be started before switching is a discharging state, the high voltage end current sampling value will be the first initial current value, effectively ensuring a more stable DC bus voltage.

[0061] In one embodiment of the present invention, the step of controlling the power supply module to be started up to start up according to a current source control mode includes: The power supply module includes a step of switching an operation mode selection switch of the power supply module to be started to a current source control mode, and controlling the power supply module to be started in the current source control mode.

[0062] In addition, combining FIG. 5, the controller of the power supply module to be started up includes a voltage controller and a current controller, and has a bus voltage source mode, a port voltage source control mode, and a current source control mode. Therefore, by switching the operation mode selection switch of the power supply module to be started up to the current source control mode, it can start up and operate in the current source control mode, and gradually bear the system required power, for example, the total power of the system. This ensures that when bearing the system power during the switching process, it will not affect the DC bus voltage.

[0063] In one embodiment of the present invention, the step of controlling the power supply module to be started to start up according to a current source control mode and controlling the given current value to change from a first initial current value to a target current value includes: The method includes controlling the power supply module to be started so that the current value changes from a first initial current value to the target current value at a preset rate of change.

[0064] In addition, during startup of the power supply module in the current source control mode, the control device can control the first initial current value to gradually change to the target current value at a preset change rate, so that the power supply module can gradually bear the total power of the system during startup and ensure the stability of the converter control signals and the DC bus voltage in the power supply module. The preset change rate can be set by an operator in the control device or the power supply module.

[0065] In one embodiment of the present invention, the step of controlling the given current value to change from a first initial current value to a target current value further includes the step of controlling the time for changing the first initial current value to the target current value to within 0 to 2 seconds.

[0066] In addition, during the process of switching the operating mode, the power supply module to be started is started according to the current source control mode, and the time required for changing the first initial current value to the target current value is controlled within 0 to 2 seconds. In other words, the first initial current value is rapidly changed (for example, gradually increased) to the target current value in a very short time, so that the start-up operation of the power supply module to be started can be completed quickly, and thus a large change in the power of the low-voltage end electrical appliances can be avoided during the switching.

[0067] In one embodiment of the present invention, the step of controlling the power supply module to be started to switch its control mode to a voltage source control mode includes: The method includes controlling the power supply module to be started so as to switch its control mode to a bus voltage source control mode.

[0068] Furthermore, when the power supply module to be started completes the start-up operation in the current source control mode, in other words, when the given current value of the power supply module to be started reaches the target current value, the power supply module to be started can bear the total power of the system, and the current source control mode of the power supply module to be started is controlled to switch to the bus voltage source control mode, so that the DC bus voltage can be effectively controlled, and the stability of the DC bus voltage can be ensured while switching the operation mode.

[0069] In one embodiment of the present invention, the step of controlling the power supply module to be started to switch to a bus voltage source control mode includes: obtaining a voltage reference value and a voltage feedback value of the power supply module to be started before switching; generating an inductance current reference value or a high voltage current reference value based on the voltage reference value and the voltage feedback value; and controlling the voltage of the DC bus based on the inductance current reference value or the high voltage current reference value.

[0070] The voltage reference value and voltage feedback value of the power supply module to be started before switching are obtained to provide parameter basis for subsequent control of the DC bus by the power supply module to be started, and the bus voltage sampled value of the power supply module to be started before switching is used as the voltage feedback value of its voltage controller, and the target voltage value is used as the voltage reference value of its voltage controller. The voltage controller of the power supply module to be started generates an inductance current reference value and a high-voltage current reference value based on the obtained voltage reference value and voltage feedback value, and uses these as input values ​​for the current controller of the power supply module to be started, thereby providing parameter basis for starting up the power supply module to be started in current source control mode after switching. If the power supply module to be started is a power factor correction converter, the inductance current reference value is generated based on the voltage reference value and voltage feedback value. If the power supply module to be started is a high-voltage DC converter, the high-voltage current reference value is generated based on the voltage reference value and voltage feedback value. The voltage of the DC bus is controlled based on the inductance current reference value or the high-voltage current reference value; in other words, before switching, the inductance current reference value or the high-voltage current reference value is set as the current reference value in the power supply module to be started up according to the current source control mode after switching.

[0071] In one embodiment of the present invention, the step of generating an inductance current reference value or a high voltage current reference value based on the voltage reference value and the voltage feedback value comprises: Prior to switching the power supply module to be started, the method includes a step of collecting the port current sampling values ​​by a current controller of the power supply module to be started, and calculating and obtaining the inductance current reference value or the high-voltage current reference value by a voltage controller of the power supply module to be started based on the voltage reference value, the voltage feedback value, and the port current sampling values.

[0072] Prior to switching the power supply module to be started, the current controller of the power supply module to be started can collect port current sampled values. If the power supply module to be started is a power factor correction converter, the port current sampled values ​​are AC end current sampled values, and the voltage controller of the power factor correction converter can obtain the inductance current reference value by performing certain calculations based on the bus voltage reference value, the bus voltage feedback value, and the AC end current sampled values. If the power supply module to be started is a high-voltage DC converter, the port current sampled values ​​are HV end current sampled values, and the voltage controller of the high-voltage DC converter can obtain the HV current reference value by performing certain calculations based on the bus voltage reference value, the bus voltage feedback value, and the HV end current sampled values. In other words, setting the port current sampled values ​​before switching, such as the AC end current sampled values ​​or the HV end current sampled values, as the initial values ​​calculated and output by the voltage controller in the voltage source control mode after switching is effective in more accurately obtaining the inductance current reference value or the HV current reference value after the power supply module to be started is switched.

[0073] In one embodiment of the present invention, the step of controlling the power supply module to be started up in a current source control mode includes: acquiring an operating state of the power supply module to be started before switching; When the operation state of the power supply module to be started before switching is the port voltage source control mode, first shutting down the power supply module to be started, and then controlling the power supply module to be started to start in the current source control mode; Includes:

[0074] In addition, in order to control the startup mode of the power supply module to be started, the operating state of the power supply module to be started before switching is obtained, and if the operating state of the power supply module to be started before switching is the port voltage source control mode, the power supply module to be started is first shut down, and then controlled to start up in the current source control mode, thereby preventing the port current sampling value of the power supply module to be started up before switching from interfering with the startup of the current source control mode of the power supply module to be started up after switching and affecting the adjustment of the given current value.

[0075] In one embodiment of the present invention, the in-vehicle charger operation mode switching control method includes: Controlling the voltage of the DC bus; The method further includes controlling the shutdown of the original power supply module or controlling the original power supply module to start up in a current source control mode in which the given current value is a second initial current value (which becomes approximately zero).

[0076] Furthermore, after controlling the control mode of the power supply module to be started up to switch to the voltage source control mode, the DC bus voltage can be controlled and, at the same time, the original power supply module can be controlled to shut down according to the actual operating conditions, or the original power supply module can be started up in a current source control mode in which the given current value is a second initial current value, and the second initial current value is approximately zero, thereby fully completing the switching of different operating modes of the on-board charger.

[0077] In addition, if the original power supply module before switching needs to operate in port voltage source control mode after switching, the operation direction selection switch of the controller of the original power supply module is set to position 2 (implemented by software), and the control mode selection switch is set to position 4 (implemented by software). In this case, the target port voltage (e.g., the target value / expected value of the AC end voltage or the high end voltage) is used as the voltage reference value of the voltage controller, the port voltage sampling value (the AC end voltage sampling value or the high end voltage sampling value) is used as the voltage feedback value of the voltage controller, and the port current sampling value (the AC end current sampling value or the high end current sampling value) is used as the current feedback value of the current controller, and finally the control signal for the port voltage source control mode is obtained.

[0078] The specific steps for switching the on-board charger from operation mode 1 to operation mode 4 are as follows: The on-board charger is in operation mode 1, and the PFC controls the voltage of the DC bus and outputs power to the high-voltage end and the low-voltage end; A step of calculating the high-voltage end output current required to bear the entire system power based on the current power P at the low-voltage end and the high-voltage end voltage U using the formula I=P / U, and setting this as the target current value; Switching the control mode of the HVDC to the current source control mode (setting the operation mode selection switch to 3), and setting the current high voltage end current sampling value as the first initial current value; Starting up the HVDC in a current source control mode and controlling a given current value to change from a first initial current value to a target current value; Switching the control mode of the HVDC from current source control mode to bus voltage source control mode (setting the operation direction selection switch to position 1 and setting the operation mode selection switch to position 4), controlling the voltage of the DC bus and turning off the PFC; Controlling the PFC to start up in AC voltage source control mode (setting the operation direction selection switch to position 2 and the operation mode selection switch to position 4); The on-board charger is switched from operation mode 1 to operation mode 4, and in this case, the HVDC controls the bus voltage to output power to the AC end and the low-voltage end.

[0079] Another embodiment of the present invention provides an on-board charger operation mode switching control device, comprising: an acquisition unit for acquiring an operation mode switching signal of the on-board charger, the operation mode switching signal including a switching signal for switching from controlling a voltage of a DC bus bar by an original power supply module among different power supply modules of the on-board charger to controlling the voltage of the DC bus bar by a power supply module to be activated; and a processing unit that controls the power supply module to be started up so that it starts up in a current source control mode based on the operation mode switching signal and adjusts a given current value according to an operation status until it bears the system required power, controls the control mode of the power supply module to be started up to switch to a voltage source control mode, and causes the power supply module to be started up to control the voltage of a DC bus.

[0080] As a result, the vehicle charger operation mode switching control device is used to realize the above-mentioned vehicle charger operation mode switching control method, and therefore has at least all the technical effects of the above-mentioned vehicle charger operation mode switching control method, and will not be repeated here.

[0081] Another embodiment of the present invention provides an on-board charger, including a computer-readable storage medium storing a computer program and a processor, which, when loaded and executed by the processor, realizes the above-described on-board charger operation mode switching control method. The processor can be regarded as the control device in Figure 8. The on-board charger further includes an original power module and a power module to be activated.

[0082] Another embodiment of the present invention provides a computer-readable storage medium having a computer program stored therein, which, when read and executed by a processor, realizes the above-described vehicle charger operation mode switching control method.

[0083] Although the present disclosure has been disclosed as above, the scope of protection of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and all of these changes and modifications fall within the scope of protection of the present invention.

Claims

1. An in-vehicle charger operation mode switching control method, a step of acquiring an operation mode switching signal of the on-board charger, the operation mode switching signal including a switching signal for switching from controlling the voltage of a DC bus by an original power supply module among different power supply modules of the on-board charger to controlling the voltage of the DC bus by a power supply module to be activated; a step of starting the power supply module to be started in a current source control mode based on the operation mode switching signal, and controlling the power supply module to adjust a given current value according to an operation state until the power required by the system is satisfied; controlling the power supply module to be started to switch its control mode to a voltage source control mode, and causing the power supply module to be started to control the voltage of a DC bus; Including, the system power requirement is the total power of the system; The step of starting the power supply module to be started in a current source control mode and controlling the power supply module to adjust a given current value according to an operating condition until the total power of the system is loaded includes: controlling the power supply module to be started up to start up according to a current source control mode, and controlling the given current value to change from a first initial current value to a target current value, wherein the first initial current value is determined by an operating state of the power supply module to be started up before switching, and the target current value is determined by a total power of the system and a port voltage of the power supply module to be started up; 10. A method for controlling switching of an operation mode of an in-vehicle charger, comprising:

2. The step of determining the first initial current value based on the operating state of the power supply module to be started before switching, obtaining the operation state and port current sampling value of the power supply module to be started before switching; setting the port current sampled value as the first initial current value; The method for controlling switching of an operation mode of an on-board charger according to claim 1, further comprising:

3. The port current sampling value is an AC end current sampling value or a high voltage end current sampling value of the on-board charger.

3. The method for controlling switching of an operation mode of an on-board charger according to claim 2.

4. The step of controlling the power supply module to be started up to start up in accordance with a current source control mode includes: switching an operation mode selection switch of the power supply module to be started up to a current source control mode, and controlling the power supply module to be started up in the current source control mode; The method for controlling switching of an operation mode of an on-board charger according to claim 1, further comprising:

5. The step of controlling the power supply module to be started up to start up according to a current source control mode and controlling the given current value to change from a first initial current value to a target current value includes: controlling the power supply module to be started so that the current value changes from the first initial current value to the target current value at a predetermined rate of change; The method for controlling switching of an operation mode of an on-board charger according to claim 1, further comprising:

6. The step of controlling the power supply module to be started to switch its control mode to a voltage source control mode includes: controlling the control mode of the power supply module to be started to switch to a bus voltage source control mode; 3. The method for controlling switching of an operation mode of an on-board charger according to claim 2, further comprising:

7. The step of controlling the power supply module to be started so as to switch its control mode to a bus voltage source control mode includes: obtaining a voltage reference value and a voltage feedback value of the power supply module to be started before switching; generating an inductance current reference value or a high voltage current reference value based on the voltage reference value and the voltage feedback value; controlling the voltage of the DC bus based on the inductance current reference value or the high voltage current reference value; The method for controlling switching of an operation mode of an on-board charger according to claim 6, further comprising:

8. generating an inductance current reference value or a high voltage current reference value based on the voltage reference value and the voltage feedback value, Prior to switching the power supply module to be started, a current controller of the power supply module to be started collects the port current sampling values, and a voltage controller of the power supply module to be started calculates and obtains the inductance current reference value or the high-voltage current reference value based on the voltage reference value, the voltage feedback value, and the port current sampling values; The method for controlling switching of an operation mode of an on-board charger according to claim 7, further comprising:

9. The step of controlling the power supply module to be started up in a current source control mode includes: acquiring an operating state of the power supply module to be started before switching; When the operation state of the power supply module to be started before switching is the port voltage source control mode, first shutting down the power supply module to be started, and then controlling the power supply module to be started to start in the current source control mode; The method for controlling switching of an operation mode of an on-board charger according to claim 1, further comprising:

10. Controlling the voltage of the DC bus; controlling the original power supply module to shut down or to start up in a current source control mode in which a given current value is a second initial current value; The method for controlling switching of an operation mode of an on-board charger according to any one of claims 1 to 9, further comprising:

11. An on-board charger operation mode switching control device, an acquisition unit for acquiring an operation mode switching signal of the on-board charger, the operation mode switching signal including a switching signal for switching from controlling a voltage of a DC bus bar by an original power supply module among different power supply modules of the on-board charger to controlling the voltage of the DC bus bar by a power supply module to be activated; a processing unit that starts the power supply module to be started in a current source control mode based on the operation mode switching signal, controls the power supply module to adjust a given current value according to an operation state until the power required by the system is borne, controls the control mode of the power supply module to be started to be switched to a voltage source control mode, and causes the power supply module to be started to control the voltage of a DC bus; Including, the system power requirement is the total power of the system; The step of starting the power supply module to be started in a current source control mode and controlling the power supply module to adjust a given current value according to an operating condition until the total power of the system is loaded includes: controlling the power supply module to be started up to start up according to a current source control mode, and controlling the given current value to change from a first initial current value to a target current value, wherein the first initial current value is determined by an operating state of the power supply module to be started up before switching, and the target current value is determined by a total power of the system and a port voltage of the power supply module to be started up; 10. An apparatus comprising:

12. 10. An on-board charger comprising: a computer-readable storage medium storing a computer program; and a processor, wherein when the computer program is read and executed by the processor, the on-board charger realizes the on-board charger operation mode switching control method according to any one of claims 1 to 9.

13. A computer-readable storage medium storing a computer program, the computer program being characterized in that, when read and executed by a processor, the computer-readable storage medium realizes the vehicle charger operation mode switching control method described in any one of claims 1 to 9.

Images