A control method and device for regulating voltage of electric vehicle charging

Abstract

The application discloses a control method and device for adjusting voltage of electric vehicle charging, and the method comprises the following steps: receiving a charging completion signal of a vehicle-mounted battery management system, obtaining a frequency measurement value of an alternating current port, judging whether the frequency measurement value is within a preset frequency range, if not, setting a first preset typical value voltage or a second preset typical value voltage according to the high or low of the frequency measurement value, and if yes, adjusting the frequency measurement value to set an adjusted voltage, so that the direct current bus capacitor releases or absorbs energy to the AC / DC rectifier by controlling the direct current bus capacitor voltage when the external power grid needs inertia support. It can be seen that when the charging power supply module is in a non-charging mode, the frequency change in the alternating current port is used to determine whether the system has the demand of inertia support, and the corresponding adjusted voltage is set to provide the inertia support, so that the energy flow direction of the energy source of the capacitor in the charging power supply module is controlled, and the required inertia support is provided for the power grid connected to the alternating current port.

Description

Technical Field

[0001] This application relates to the field of battery charging, and more specifically, to a control method and apparatus for regulating the charging voltage of an electric vehicle. Background Technology

[0002] With the continuous increase in electricity demand, the power system is also developing rapidly, giving rise to more power electronic devices to enrich and complicate the power system. However, with the high proportion of power electronic devices connected to the grid, the power grid has exhibited a characteristic of decreasing inertia. Therefore, high-power electric vehicle fast charging and discharging technologies and equipment with inertia response characteristics have become a key focus. One of the key factors in maintaining the stability of electric vehicle charging inertia is the ability to quickly control the energy of the capacitors in the charging power module.

[0003] Currently, electric vehicle charging power modules do not have voltage regulation control for inertia control purposes. During fast charging, when the charging frequency changes too quickly, the voltage of the capacitor in the charging power module still operates at the voltage of the normal mode, which eventually leads to the loss of energy source of the capacitor. As a result, the charging power module fails to consider the grid demand and cannot provide the corresponding inertia support function.

[0004] By controlling the charging voltage of the electric vehicle through the charging power module, the energy flow of the energy source of the capacitor in the charging power module is controlled, so that the charging power module can still provide corresponding inertial support to the power grid during the charging process. Summary of the Invention

[0005] In view of the above problems, this application is made to provide a control method and device for regulating the charging voltage of an electric vehicle, so as to control the energy flow of the energy source of the capacitor in the charging power module, thereby enabling the charging power module to still provide corresponding inertia support function to the power grid during the charging process.

[0006] To achieve the above objectives, the following specific solutions are proposed:

[0007] A method for controlling the voltage regulation during electric vehicle charging is applied to an AC (Alternating Current) / DC (Direct Current) rectifier in a charging power module. The charging power module further includes an AC port, a DC bus capacitor, and a DC / DC converter. The AC / DC rectifier is connected to the DC / DC converter via the DC bus capacitor, and the AC port is connected to the AC / DC rectifier. The method includes:

[0008] Upon receiving the charging completion signal from the vehicle battery management system, the frequency measurement value of the AC port is obtained;

[0009] Determine whether the measured frequency value is less than a preset lower frequency limit;

[0010] If so, the first preset typical voltage is set as the adjustment voltage so that the DC bus capacitor can release energy to the AC / DC rectifier when the power of the DC / DC converter is 0.

[0011] If not, determine whether the frequency measurement value is greater than the preset frequency upper limit;

[0012] If so, the second preset typical voltage is set as the adjustment voltage so that the DC bus capacitor can absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. The second preset typical voltage is greater than the first preset typical voltage.

[0013] If not, the frequency measurement value is adjusted by a preset steady-state frequency threshold to obtain an adjustment voltage and set the adjustment voltage so that the DC bus capacitor can release or absorb energy to the AC / DC rectifier when the power of the DC / DC converter is 0.

[0014] Optionally, the method further includes:

[0015] Upon receiving the charging status signal from the vehicle battery management system, the third preset typical voltage value is set as the adjustable voltage.

[0016] Optionally, adjusting the frequency measurement value by a preset frequency steady-state threshold to obtain and set the adjustment voltage includes:

[0017] The frequency difference is obtained by subtracting the frequency measurement value from the preset steady-state frequency threshold.

[0018] Multiply the frequency difference by a preset frequency change scaling factor to obtain the scaled voltage;

[0019] The scaling voltage is added to the third preset typical voltage value to obtain the adjustment voltage, and the adjustment voltage is set.

[0020] Optionally, the AC / DC rectifier includes several switching circuits;

[0021] After setting the first preset typical voltage value to the regulated voltage, the method further includes:

[0022] Obtain the voltage measurement value of the DC bus capacitor;

[0023] The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal;

[0024] The output voltage signal is subjected to current control and modulation to obtain a switching control signal, which controls the on / off state of each switching circuit of the AC / DC rectifier.

[0025] Optionally, the AC / DC rectifier includes several switching circuits;

[0026] After setting the second preset typical voltage value to the adjusted voltage, the method further includes:

[0027] Obtain the voltage measurement value of the DC bus capacitor;

[0028] The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal;

[0029] The output voltage signal is subjected to current control and modulation to obtain a switching control signal, which controls the on / off state of each switching circuit of the AC / DC rectifier.

[0030] Optionally, the AC / DC rectifier includes several switching circuits;

[0031] After adjusting the frequency measurement value through a preset frequency steady-state threshold to obtain an adjustment voltage and setting the adjustment voltage, the method further includes:

[0032] Obtain the voltage measurement value of the DC bus capacitor;

[0033] The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal;

[0034] The output voltage signal is subjected to current control and modulation to obtain a switching control signal, which controls the on / off state of each switching circuit of the AC / DC rectifier.

[0035] Optionally, the AC / DC rectifier includes several switching circuits;

[0036] After setting the third preset typical voltage value to the adjusted voltage, the method further includes:

[0037] Obtain the voltage measurement value of the DC bus capacitor;

[0038] The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal;

[0039] The output voltage signal is subjected to current control and modulation to obtain a switching control signal, which controls the on / off state of each switching circuit of the AC / DC rectifier.

[0040] Optionally, the first preset typical voltage is 600V.

[0041] Optionally, the second preset typical voltage is 1000V.

[0042] A control device for regulating the charging voltage of an electric vehicle is applied to an AC / DC rectifier in a charging power module. The charging power module further includes an AC port, a DC bus capacitor, and a DC / DC converter. The AC / DC rectifier is connected to the DC / DC converter through the DC bus capacitor, and the AC port is connected to the AC / DC rectifier. The device includes:

[0043] The frequency value acquisition unit is used to receive the charging completion signal from the vehicle battery management system and acquire the frequency measurement value of the AC port;

[0044] A frequency value lower limit determination unit is used to determine whether the frequency measurement value is less than a preset frequency lower limit;

[0045] The first voltage setting unit is used to set a first preset typical value voltage as an adjustment voltage when the frequency measurement value is less than a preset lower frequency limit, so that the DC bus capacitor can release energy to the AC / DC rectifier when the power of the DC / DC converter is 0.

[0046] The frequency value upper limit judgment unit is used to determine that the frequency measurement value is greater than the preset frequency upper limit when the frequency measurement value is not less than the preset frequency lower limit;

[0047] The second voltage setting unit is used to set a second preset typical value voltage as an adjustment voltage when the frequency measurement value is greater than the preset frequency upper limit, so that the DC bus capacitor can absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. The second preset typical value voltage is greater than the first preset typical value voltage.

[0048] The voltage regulation unit is used to adjust the frequency measurement value by a preset frequency steady-state threshold when the frequency measurement value is not greater than the preset frequency upper limit, to obtain the regulation voltage and set the regulation voltage so that the DC bus capacitor can release or absorb energy to the AC / DC rectifier when the power of the DC / DC converter is 0.

[0049] Optionally, the device may also include:

[0050] The third voltage setting unit is used to receive the charging status signal from the vehicle battery management system and set the third preset typical voltage value as the adjustable voltage.

[0051] Optionally, the voltage regulation unit includes:

[0052] The frequency difference calculation unit is used to subtract the frequency measurement value from the preset steady-state threshold to obtain the frequency difference when the frequency measurement value is not greater than the preset upper frequency limit.

[0053] A scaling voltage determination unit is used to multiply the frequency difference by a preset frequency change scaling factor to obtain a scaling voltage;

[0054] The voltage adjustment determination unit is used to add the scaling voltage to the third preset typical value voltage to obtain the adjustment voltage, and to set the adjustment voltage.

[0055] Optionally, the AC / DC rectifier includes several switching circuits;

[0056] The device also includes:

[0057] The first voltage measurement unit is used to obtain the voltage measurement value of the DC bus capacitor after the first voltage setting unit sets the first preset typical value voltage to the adjustment voltage;

[0058] The first voltage signal determination unit is used to perform voltage control on the voltage measurement value through the adjustment voltage to obtain an output voltage signal;

[0059] The first switch signal determination unit is used to perform current control and modulation on the output voltage signal to obtain a switch control signal, so as to control the on / off state of each switch circuit of the AC / DC rectifier.

[0060] Optionally, the AC / DC rectifier includes several switching circuits;

[0061] The device also includes:

[0062] The second voltage measurement unit is used to obtain the voltage measurement value of the DC bus capacitor after the second voltage setting unit sets the second preset typical value voltage to the adjustment voltage;

[0063] The second voltage signal determination unit is used to perform voltage control on the voltage measurement value through the adjustment voltage to obtain an output voltage signal;

[0064] The second switch signal determination unit is used to perform current control and modulation on the output voltage signal to obtain a switch control signal, so as to control the on / off state of each switch circuit of the AC / DC rectifier.

[0065] Optionally, the AC / DC rectifier includes several switching circuits;

[0066] The device also includes:

[0067] A capacitor voltage acquisition unit is used to acquire the voltage measurement value of the DC bus capacitor after the voltage adjustment unit adjusts the frequency measurement value through a preset frequency steady-state threshold to obtain and set the adjustment voltage.

[0068] An output signal determination unit is used to perform voltage control on the voltage measurement value through the adjustment voltage to obtain an output voltage signal;

[0069] The output signal modulation unit is used to perform current control and modulation on the output voltage signal to obtain a switch control signal, so as to control the on / off state of each switch circuit of the AC / DC rectifier.

[0070] Optionally, the AC / DC rectifier includes several switching circuits;

[0071] The device also includes:

[0072] The third voltage measurement unit is used to obtain the voltage measurement value of the DC bus capacitor after the third voltage setting unit sets the third preset typical value voltage to the adjustment voltage;

[0073] The third voltage signal determination unit is used to perform voltage control on the voltage measurement value through the adjustment voltage to obtain an output voltage signal;

[0074] The third switch signal determination unit is used to perform current control and modulation on the output voltage signal to obtain a switch control signal, so as to control the on / off state of each switch circuit of the AC / DC rectifier.

[0075] By means of the above technical solution, this application obtains the frequency measurement value of the AC port by receiving the charging completion signal from the vehicle battery management system, determines whether the frequency measurement value is less than a preset lower frequency limit, and if so, sets a first preset typical value voltage as an adjustment voltage so that the DC bus capacitor can release energy to the AC / DC rectifier when the power of the DC / DC converter is 0. If not, it determines whether the frequency measurement value is greater than a preset upper frequency limit, and if so, sets a second preset typical value voltage as an adjustment voltage so that the DC bus capacitor can absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. The second preset typical value voltage is greater than the first preset typical value voltage. If not, the frequency measurement value is adjusted by a preset frequency steady-state threshold to obtain an adjustment voltage and set the adjustment voltage so that the DC bus capacitor can release or absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. Therefore, when the charging power module is in non-charging mode, the frequency change in the AC port is used to determine whether the system needs inertia support. By setting the corresponding adjustment voltage, inertia support is provided, thereby controlling the energy flow of the capacitor energy source in the charging power module and providing the required inertia support to the power grid connected to the AC port. Attached Figure Description

[0076] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0077] Figure 1 A schematic diagram of a charging power supply module architecture for controlling the charging voltage regulation of an electric vehicle, provided in an embodiment of this application;

[0078] Figure 2 A circuit topology diagram of a charging power module provided in an embodiment of this application;

[0079] Figure 3 A schematic diagram of the process structure for controlling the charging voltage regulation of an electric vehicle according to an embodiment of this application;

[0080] Figure 4 This is a schematic diagram of the device structure for controlling the charging voltage regulation of an electric vehicle, provided in an embodiment of this application. Detailed Implementation

[0081] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0082] Figure 1 A charging power supply module architecture for controlling the charging voltage regulation of electric vehicles provided in the embodiments of this application, such as Figure 1 As shown, the charging power module architecture may include:

[0083] AC / DC rectifier 10, DC / DC converter 20, DC bus capacitor 30 and AC port 40.

[0084] The AC / DC rectifier 10 can be connected to the DC / DC converter 20 via the DC bus capacitor 30, and the AC port 40 can be connected to the AC / DC rectifier 10.

[0085] Specifically, the AC / DC rectifier 10 can be a bidirectional AC / DC rectifier, which can be composed of a two-level six-switch rectifier, a neutral point clamped (NPC) converter, and a T-type three-level converter, allowing energy to flow bidirectionally. The DC / DC converter can be a unidirectional DC / DC converter, and the circuit topology of the unidirectional DC / DC converter can be a phase-shifted full-bridge converter or an LLC resonant converter.

[0086] AC / DC rectifier 10 may include a two-level converter and a three-level converter.

[0087] Among them, the withstand voltage of the two-level converter in the AC / DC rectifier 10 is not less than 1.2kV, and the withstand voltage of the three-level converter in the AC / DC rectifier 10 can be not less than 650V.

[0088] The withstand voltage of the DC bus capacitor 30 can be no less than 1.2kV.

[0089] It is understandable that the DC bus capacitor 30 serves as an energy source for maintaining inertia, and the capacity of the DC bus capacitor 30 can be higher than a preset capacity threshold. The preset capacity threshold can be no lower than the minimum standard value for achieving inertia support.

[0090] Figure 2The circuit topology of the charging power supply module is shown. The charging power supply module consists of a two-level six-switch rectifier corresponding to the AC / DC rectifier 10, a Cdc capacitor corresponding to the DC bus capacitor 30, and a full-bridge LLC resonant converter corresponding to the DC / DC converter 20. Figure 2 The circuit consists of ten switching circuits, Q1-Q10, each with a withstand voltage of no less than 1.2kV.

[0091] based on Figure 1 The charging power module architecture shown is as follows: Figure 3 This application illustrates a control method for regulating the charging voltage of an electric vehicle, which can be applied to the AC / DC rectifier 10 in a charging power module. (Refer to...) Figure 3 The method may include the following steps:

[0092] Step S110: Receive the charging completion signal from the vehicle battery management system and obtain the frequency measurement value of the AC port.

[0093] Specifically, when the AC / DC rectifier 10 receives a charging completion signal from the vehicle battery management system, it indicates that the AC / DC rectifier 10 has entered standby mode or inertia support mode.

[0094] Understandably, determining whether the AC / DC rectifier 10 enters standby mode or inertia support mode requires first determining the magnitude of the frequency measurement value at the AC port.

[0095] Step S120: Determine whether the frequency measurement value is less than the preset lower frequency limit. If yes, proceed to step S130; otherwise, proceed to step S140.

[0096] Specifically, the preset lower frequency limit can represent the minimum value of the normal variation range of the frequency measurement value. When the frequency measurement value of the AC port is less than the preset lower frequency limit, it can indicate that the frequency measurement value of the AC port is low and changes too fast, and the AC / DC rectifier 10 enters the inertia support mode.

[0097] The preset lower frequency limit can be customized and can be set to 49Hz.

[0098] Step S130: Set the first preset typical voltage value to the adjustable voltage.

[0099] Specifically, the first preset typical voltage value can represent the voltage value that needs to be set instantaneously when the frequency measurement value is lower than the preset lower limit in inertia support mode.

[0100] The first preset typical voltage value can be customized or determined according to the circuit topology of the charging power module, and can be set to 600V.

[0101] It is understandable that when the AC / DC rectifier 10 is in inertia support mode, the power of the DC / DC converter 20 is 0. Therefore, the DC bus capacitor 30 can release energy to the AC / DC rectifier 10 when the power of the DC / DC converter 20 is 0.

[0102] Step S140: Determine whether the frequency measurement value is greater than the preset frequency upper limit. If yes, proceed to step S150; otherwise, proceed to step S160.

[0103] Specifically, the preset upper frequency limit can represent the highest value of the normal variation range of the frequency measurement value. When the frequency measurement value of the AC port is greater than the preset lower frequency limit, it can indicate that the frequency measurement value of the AC port is high and changes too fast, and the AC / DC rectifier 10 enters the inertia support mode.

[0104] The preset frequency upper limit can be customized and can be set to 51Hz.

[0105] Step S150: Set the second preset typical voltage value to the adjustable voltage.

[0106] Specifically, the second preset typical voltage value can represent the voltage value that needs to be set instantaneously when the frequency measurement value is higher than the preset frequency upper limit in inertia support mode.

[0107] The second preset typical voltage can be greater than the first preset typical voltage. The second preset typical voltage can be customized or determined according to the circuit topology of the charging power module, and can be set to 1000V.

[0108] It is understandable that when the AC / DC rectifier 10 is in inertia support mode, the power of the DC / DC converter 20 is 0. Therefore, the DC bus capacitor 30 can absorb energy from the AC / DC rectifier 10 when the power of the DC / DC converter 20 is 0.

[0109] Step S160: Adjust the frequency measurement value by a preset frequency steady-state threshold to obtain an adjustment voltage and set the adjustment voltage.

[0110] Specifically, when the frequency measurement value of the AC port is between the preset upper frequency limit and the preset lower frequency limit, it indicates that the frequency measurement value of the AC port is normal and the change is moderate. The AC / DC rectifier 10 enters the standby mode. At this time, the frequency measurement value can be adjusted by the preset steady-state frequency threshold to obtain the adjustment voltage and set the adjustment voltage.

[0111] The preset steady-state frequency threshold can represent the average frequency value when the charging power module is operating normally, such as 50Hz.

[0112] The electric vehicle charging voltage regulation method provided in this embodiment receives a charging completion signal from the vehicle battery management system, obtains the frequency measurement value of the AC port, and determines whether the frequency measurement value is less than a preset lower frequency limit. If so, a first preset typical value voltage is set as the regulation voltage so that the DC bus capacitor can release energy to the AC / DC rectifier when the power of the DC / DC converter is 0. If not, it determines whether the frequency measurement value is greater than a preset upper frequency limit. If so, a second preset typical value voltage is set as the regulation voltage so that the DC bus capacitor can absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. The second preset typical value voltage is greater than the first preset typical value voltage. If not, the frequency measurement value is adjusted by a preset frequency steady-state threshold to obtain the regulation voltage and set the regulation voltage so that the DC bus capacitor can release or absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. Therefore, when the charging power module is in non-charging mode, the frequency change in the AC port is used to determine whether the system needs inertia support. By setting the corresponding adjustment voltage, inertia support is provided, thereby controlling the energy flow of the capacitor energy source in the charging power module and providing the required inertia support to the power grid connected to the AC port.

[0113] Considering that electric vehicles need to be charged, voltage regulation is required during charging. Some embodiments of this application describe a method for regulating the voltage of an electric vehicle charging power supply module in charging mode. This method may include:

[0114] Upon receiving the charging status signal from the vehicle battery management system, the third preset typical voltage value is set as the adjustable voltage.

[0115] Specifically, when the AC / DC rectifier 10 receives a charging status signal from the vehicle battery management system, it indicates that the vehicle battery management system is requesting to charge the vehicle, and the AC / DC rectifier 10 enters charging mode.

[0116] The third preset typical voltage value can represent the voltage value under normal charging conditions of the car. The third preset typical voltage value can be customized or determined according to the circuit topology of the charging power module, such as 800V.

[0117] In some embodiments of this application, the process of step S160 above, adjusting the frequency measurement value by a preset frequency steady-state threshold to obtain an adjustment voltage and setting the adjustment voltage, is described. This process may include:

[0118] S1. Subtract the frequency measurement value from the preset steady-state frequency threshold to obtain the frequency difference.

[0119] Specifically, the frequency difference can represent the degree of deviation between the measured frequency value and the preset steady-state frequency threshold. When the frequency difference is positive, it can indicate that the measured frequency value is too small, and when the frequency difference is positive, it can indicate that the measured frequency value is too large.

[0120] S2. Multiply the frequency difference by a preset frequency change scaling factor to obtain the scaled voltage.

[0121] Specifically, voltage scaling can represent the voltage amplitude that needs to be modulated based on the normal charging voltage value of a car.

[0122] The preset frequency scaling factor can be tuned by pre-simulation or experimentation, and can be customized based on the inertia of the power system connected to the AC / DC rectifier 10, for example, 200V / Hz.

[0123] S3. Add the scaling voltage to the third preset typical value voltage to obtain the adjustment voltage, and set the adjustment voltage.

[0124] Specifically, the third preset typical voltage value can represent the voltage value under normal charging conditions of a car, such as 800V. Based on the preset upper frequency limit of 51Hz, the preset lower frequency limit of 49Hz, and the preset frequency change scaling factor of 200V / Hz, the voltage adjustment range is 600V-1000V when the AC / DC rectifier 10 is in standby mode.

[0125] The electric vehicle charging voltage control method provided in this embodiment controls the voltage range of 600V-1000V when the AC / DC rectifier 10 is in standby mode. This allows the charging power module to slowly release energy when the frequency measurement value is too high, and to instantly absorb energy when the frequency of the power system where the AC / DC rectifier 10 is located is higher than the set value. Conversely, when the frequency measurement value is too low, the charging power module can slowly absorb energy, and to instantly release energy when the frequency of the power system where the AC / DC rectifier 10 is located is lower than the set value.

[0126] Considering that after obtaining the regulated voltage, it is applied to the circuit control in the charging power module to provide inertia support for the external power grid, in some embodiments of this application, the AC / DC rectifier 10 may include several switching circuits, and may also include a control method for controlling each switching circuit in the AC / DC rectifier 10. This method can be divided into the following four cases:

[0127] The first method, executed after the process of setting the first preset typical voltage value to the regulated voltage mentioned in the above embodiments, includes the following steps:

[0128] Step S11: Obtain the voltage measurement value of the DC bus capacitor 30.

[0129] Specifically, the voltage value of the bus where DC bus capacitor 30 is located can be measured using a voltage measuring instrument.

[0130] For example Figure 2 It can measure the voltage across the Cdc terminals.

[0131] Step S12: The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal.

[0132] Specifically, the adjusted voltage can be subtracted from the measured voltage value, and the result can be input into a PI controller for voltage control to obtain the output voltage signal.

[0133] Step S13: Perform current control and modulation on the output voltage signal to obtain a switch control signal.

[0134] Specifically, the output voltage signal can be transmitted to the current control loop for current control, the current control output result can be obtained, and the current control output result can be modulated to obtain the switching control signal.

[0135] It is understood that the switch control signal can be used to control the on / off state of each switch circuit of the AC / DC rectifier.

[0136] The second method, executed after the process of setting the second preset typical voltage value to the regulated voltage mentioned in the above embodiments, includes the following steps:

[0137] Step S21: Obtain the voltage measurement value of the DC bus capacitor 30.

[0138] Step S22: The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal.

[0139] Step S23: Perform current control and modulation on the output voltage signal to obtain a switch control signal.

[0140] Steps S21-S23 above correspond one-to-one with steps S11-S13 in the foregoing embodiments. For details, please refer to the foregoing description, which will not be repeated here.

[0141] The third method, executed after the process mentioned in the above embodiments of adjusting the frequency measurement value through a preset frequency steady-state threshold to obtain an adjustment voltage and setting the adjustment voltage, includes the following steps:

[0142] Step S31: Obtain the voltage measurement value of the DC bus capacitor 30.

[0143] Step S32: The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal.

[0144] Step S33: Perform current control and modulation on the output voltage signal to obtain a switch control signal.

[0145] Steps S31-S33 above correspond one-to-one with steps S11-S13 in the previous embodiments. Please refer to the foregoing description for details, which will not be repeated here.

[0146] Fourthly, this control method is executed after the process of setting the third preset typical voltage value to the regulating voltage mentioned in the above embodiments. The method includes the following steps:

[0147] Step S41: Obtain the voltage measurement value of the DC bus capacitor 30.

[0148] Step S42: The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal.

[0149] Step S43: Perform current control and modulation on the output voltage signal to obtain a switch control signal.

[0150] Steps S41-S43 above correspond one-to-one with steps S11-S13 in the foregoing embodiments. Please refer to the foregoing description for details, which will not be repeated here.

[0151] The electric vehicle charging voltage regulation method provided in this embodiment obtains on / off control signals for controlling the on / off states of each switching circuit of the AC / DC rectifier by voltage control, current control and modulation of the regulation voltage, thereby achieving inertia support and enabling the charging power module to maintain stable inertia during the charging process.

[0152] The apparatus for controlling the charging voltage regulation of an electric vehicle provided in the embodiments of this application will be described below. The apparatus for controlling the charging voltage regulation of an electric vehicle described below can be referred to in correspondence with the method for controlling the charging voltage regulation of an electric vehicle described above.

[0153] See Figure 4 , Figure 4 This is a schematic diagram of a device for controlling the charging voltage regulation of an electric vehicle, as disclosed in an embodiment of this application.

[0154] like Figure 4As shown, the device can be applied to the AC / DC rectifier 10 in a charging power module. The charging power module also includes an AC port 40, a DC bus capacitor 30, and a DC / DC converter 20. The AC / DC rectifier 10 is connected to the DC / DC converter 20 through the DC bus capacitor 30, and the AC port 40 is connected to the AC / DC rectifier 10.

[0155] The device may include:

[0156] The frequency value acquisition unit 11 is used to receive the charging completion signal from the vehicle battery management system and acquire the frequency measurement value of the AC port;

[0157] The frequency value lower limit judgment unit 12 is used to determine whether the frequency measurement value is less than a preset frequency lower limit;

[0158] The first voltage setting unit 13 is used to set a first preset typical value voltage as an adjustment voltage when the frequency measurement value is less than the preset lower frequency limit, so that the DC bus capacitor can release energy to the AC / DC rectifier when the power of the DC / DC converter is 0.

[0159] The frequency value upper limit judgment unit 14 is used to determine that the frequency measurement value is greater than the preset frequency upper limit when the frequency measurement value is not less than the preset frequency lower limit.

[0160] The second voltage setting unit 15 is used to set a second preset typical value voltage as an adjustment voltage when the frequency measurement value is greater than the preset frequency upper limit, so that the DC bus capacitor can absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. The second preset typical value voltage is greater than the first preset typical value voltage.

[0161] The voltage regulation unit 16 is used to adjust the frequency measurement value by a preset frequency steady-state threshold when the frequency measurement value is not greater than the preset frequency upper limit, to obtain an adjustment voltage and set the adjustment voltage so that the DC bus capacitor can release or absorb energy to the AC / DC rectifier when the power of the DC / DC converter is 0.

[0162] Optionally, the device may also include:

[0163] The third voltage setting unit is used to receive the charging status signal from the vehicle battery management system and set the third preset typical voltage value as the adjustable voltage.

[0164] Optionally, the voltage regulation unit 16 includes:

[0165] The frequency difference calculation unit is used to subtract the frequency measurement value from the preset steady-state threshold to obtain the frequency difference when the frequency measurement value is not greater than the preset upper frequency limit.

[0166] A scaling voltage determination unit is used to multiply the frequency difference by a preset frequency change scaling factor to obtain a scaling voltage;

[0167] The voltage adjustment determination unit is used to add the scaling voltage to the third preset typical value voltage to obtain the adjustment voltage, and to set the adjustment voltage.

[0168] Optionally, the AC / DC rectifier includes several switching circuits;

[0169] The device also includes:

[0170] The first voltage measurement unit is used to obtain the voltage measurement value of the DC bus capacitor after the first voltage setting unit 13 sets the first preset typical value voltage to the adjustment voltage;

[0171] The first voltage signal determination unit is used to perform voltage control on the voltage measurement value through the adjustment voltage to obtain an output voltage signal;

[0172] The first switch signal determination unit is used to perform current control and modulation on the output voltage signal to obtain a switch control signal, so as to control the on / off state of each switch circuit of the AC / DC rectifier.

[0173] Optionally, the AC / DC rectifier includes several switching circuits;

[0174] The device also includes:

[0175] The second voltage measurement unit is used to obtain the voltage measurement value of the DC bus capacitor after the second voltage setting unit 15 sets the second preset typical value voltage to the adjustment voltage;

[0176] The second voltage signal determination unit is used to perform voltage control on the voltage measurement value through the adjustment voltage to obtain an output voltage signal;

[0177] The second switch signal determination unit is used to perform current control and modulation on the output voltage signal to obtain a switch control signal, so as to control the on / off state of each switch circuit of the AC / DC rectifier.

[0178] Optionally, the AC / DC rectifier includes several switching circuits;

[0179] The device also includes:

[0180] The capacitor voltage acquisition unit is used to acquire the voltage measurement value of the DC bus capacitor after the voltage adjustment unit 16 adjusts the frequency measurement value through a preset frequency steady-state threshold to obtain the adjustment voltage and sets the adjustment voltage.

[0181] An output signal determination unit is used to perform voltage control on the voltage measurement value through the adjustment voltage to obtain an output voltage signal;

[0182] The output signal modulation unit is used to perform current control and modulation on the output voltage signal to obtain a switch control signal, so as to control the on / off state of each switch circuit of the AC / DC rectifier.

[0183] Optionally, the AC / DC rectifier includes several switching circuits;

[0184] The device also includes:

[0185] The third voltage measurement unit is used to obtain the voltage measurement value of the DC bus capacitor after the third voltage setting unit sets the third preset typical value voltage to the adjustment voltage;

[0186] The third voltage signal determination unit is used to perform voltage control on the voltage measurement value through the adjustment voltage to obtain an output voltage signal;

[0187] The third switch signal determination unit is used to perform current control and modulation on the output voltage signal to obtain a switch control signal, so as to control the on / off state of each switch circuit of the AC / DC rectifier.

[0188] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0189] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. The various embodiments can be combined as needed, and the same or similar parts can be referred to each other.

[0190] The above description of the disclosed embodiments enables those skilled in the art to make or use this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for controlling the charging voltage regulation of an electric vehicle, characterized in that, An AC / DC rectifier is used in a charging power module. The charging power module further includes an AC port, a DC bus capacitor, and a DC / DC converter. The AC / DC rectifier is connected to the DC / DC converter through the DC bus capacitor. The AC port is connected to the AC / DC rectifier. The rectifier includes: Upon receiving the charging completion signal from the vehicle battery management system, the frequency measurement value of the AC port is obtained; Determine whether the measured frequency value is less than a preset lower frequency limit; If so, the first preset typical voltage is set as the adjustment voltage so that the DC bus capacitor can release energy to the AC / DC rectifier when the power of the DC / DC converter is 0. If not, determine whether the frequency measurement value is greater than the preset frequency upper limit; If so, the second preset typical voltage is set as the adjustment voltage so that the DC bus capacitor can absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. The second preset typical voltage is greater than the first preset typical voltage. If not, the frequency measurement value is adjusted by a preset steady-state frequency threshold to obtain an adjustment voltage and set the adjustment voltage so that the DC bus capacitor can release or absorb energy to the AC / DC rectifier when the power of the DC / DC converter is 0.

2. The method according to claim 1, characterized in that, Also includes: Upon receiving the charging status signal from the vehicle battery management system, the third preset typical voltage value is set as the adjustable voltage.

3. The method according to claim 2, characterized in that, The step of adjusting the frequency measurement value by a preset steady-state frequency threshold to obtain and set the adjustment voltage includes: The frequency difference is obtained by subtracting the frequency measurement value from the preset steady-state frequency threshold. Multiply the frequency difference by a preset frequency change scaling factor to obtain the scaled voltage; The scaling voltage is added to the third preset typical voltage value to obtain the adjustment voltage, and the adjustment voltage is set.

4. The method according to claim 1, characterized in that, The AC / DC rectifier includes several switching circuits; After setting the first preset typical voltage value to the regulated voltage, the method further includes: Obtain the voltage measurement value of the DC bus capacitor; The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal; The output voltage signal is subjected to current control and modulation to obtain a switching control signal, which controls the on / off state of each switching circuit of the AC / DC rectifier.

5. The method according to claim 1, characterized in that, The AC / DC rectifier includes several switching circuits; After setting the second preset typical voltage value to the adjusted voltage, the method further includes: Obtain the voltage measurement value of the DC bus capacitor; The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal; The output voltage signal is subjected to current control and modulation to obtain a switching control signal, which controls the on / off state of each switching circuit of the AC / DC rectifier.

6. The method according to claim 1, characterized in that, The AC / DC rectifier includes several switching circuits; After adjusting the frequency measurement value through a preset frequency steady-state threshold to obtain an adjustment voltage and setting the adjustment voltage, the method further includes: Obtain the voltage measurement value of the DC bus capacitor; The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal; The output voltage signal is subjected to current control and modulation to obtain a switching control signal, which controls the on / off state of each switching circuit of the AC / DC rectifier.

7. The method according to claim 2, characterized in that, The AC / DC rectifier includes several switching circuits; After setting the third preset typical voltage value to the adjusted voltage, the method further includes: Obtain the voltage measurement value of the DC bus capacitor; The voltage measurement value is controlled by the adjustment voltage to obtain an output voltage signal; The output voltage signal is subjected to current control and modulation to obtain a switching control signal, which controls the on / off state of each switching circuit of the AC / DC rectifier.

8. The method according to claim 1, characterized in that, The first preset typical voltage is 600V.

9. The method according to claim 1, characterized in that, The second preset typical voltage is 1000V.

10. A control device for regulating the charging voltage of an electric vehicle, characterized in that, An AC / DC rectifier is used in a charging power module. The charging power module further includes an AC port, a DC bus capacitor, and a DC / DC converter. The AC / DC rectifier is connected to the DC / DC converter through the DC bus capacitor. The AC port is connected to the AC / DC rectifier. The rectifier includes: The frequency value acquisition unit is used to receive the charging completion signal from the vehicle battery management system and acquire the frequency measurement value of the AC port; A frequency value lower limit determination unit is used to determine whether the frequency measurement value is less than a preset frequency lower limit; The first voltage setting unit is used to set a first preset typical value voltage as an adjustment voltage when the frequency measurement value is less than a preset lower frequency limit, so that the DC bus capacitor can release energy to the AC / DC rectifier when the power of the DC / DC converter is 0. The frequency value upper limit judgment unit is used to determine that the frequency measurement value is greater than the preset frequency upper limit when the frequency measurement value is not less than the preset frequency lower limit; The second voltage setting unit is used to set a second preset typical value voltage as an adjustment voltage when the frequency measurement value is greater than the preset frequency upper limit, so that the DC bus capacitor can absorb energy from the AC / DC rectifier when the power of the DC / DC converter is 0. The second preset typical value voltage is greater than the first preset typical value voltage. The voltage regulation unit is used to adjust the frequency measurement value by a preset frequency steady-state threshold when the frequency measurement value is not greater than the preset frequency upper limit, to obtain the regulation voltage and set the regulation voltage so that the DC bus capacitor can release or absorb energy to the AC / DC rectifier when the power of the DC / DC converter is 0.

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