CN112440767B

CN112440767B - Charging control method, system and storage medium thereof

Info

Publication number: CN112440767B
Application number: CN201910814683.7A
Authority: CN
Inventors: 王兴辉; 王超; 刘伟冬
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2019-08-30
Filing date: 2019-08-30
Publication date: 2022-09-09
Anticipated expiration: 2039-08-30
Also published as: CN112440767A

Abstract

The application relates to the technical field of electronics, and provides a charging control method, a charging control system and a storage medium thereof, which are applied to a circuit comprising a PFC module, wherein the method comprises the following steps of; acquiring four-phase control signals, wherein the four-phase control signals comprise high-frequency bridge arm control signals and power-frequency bridge arm control signals, and the high-frequency bridge arm control signals comprise first control signals, second control signals and third control signals which are sequentially different by preset phases; and controlling the working state of the power frequency bridge arm according to the power frequency bridge arm control signal, and sequentially controlling the alternate conduction of power switches in a first phase bridge arm, a second phase bridge arm and a third phase bridge arm of the high-frequency bridge arm module according to the first control signal, the second control signal and the third control signal so as to charge the battery. Through the implementation of this application, can solve the battery charging technology among the prior art and have the current ripple that contains the circuit production of heterogeneous PFC module too big, the problem of the easy damage of electronic components in the circuit.

Description

Charging control method, system and storage medium thereof

Technical Field

The present application relates to the field of electronic technologies, and in particular, to a charging control method and system, and a storage medium thereof.

Background

In recent years, as the technology of electric vehicles is continuously mature, the market acceptance of electric vehicles is continuously improved, more and more electric vehicles enter the society and families, great convenience is brought to people going out, and the vehicle-mounted charger is used as an important part on the electric vehicle and can guarantee the charging and discharging process of a battery. In the market, a multiphase PFC (Power Factor Correction) module is mostly adopted to correct the Power Factor in the ac charging process, so as to improve the efficiency and quality of charging the battery. However, in the market, a multiphase PFC module generally needs to adopt a multiphase bridge arm, and then the multiphase bridge arm is synchronously controlled to realize PFC power correction and rectification, so that the multiphase PFC module outputs boosted direct current.

Although the synchronous control method can be used for realizing PFC power correction and rectification, the synchronous control among the multiphase bridge arms causes current ripples generated by the multiphase bridge arms in the PFC module to be mutually superposed, so that the current ripples are overlarge, and electronic components in a circuit are easily damaged.

In summary, the battery charging technology in the prior art has the problem that the current ripple generated by the circuit including the multiphase PFC module is too large, and the electronic components in the circuit are easily damaged.

Disclosure of Invention

The application aims to provide a charging control method, a charging control system and a storage medium thereof, and aims to solve the problems that in the prior art, the current ripple generated by a circuit comprising a multiphase PFC module is overlarge and electronic components in the circuit are easy to damage in the battery charging technology.

A first embodiment of the present application provides a charge control method applied to a circuit including a PFC module, where the PFC module includes a high-frequency bridge arm module and a power-frequency bridge arm, and the high-frequency bridge arm module includes a three-phase bridge arm, and the charge control method includes:

acquiring four-phase control signals, wherein the four-phase control signals comprise high-frequency bridge arm control signals and power-frequency bridge arm control signals, and the high-frequency bridge arm control signals comprise a first control signal, a second control signal and a third control signal which sequentially differ by a preset phase;

and controlling the working state of the power frequency bridge arm according to the power frequency bridge arm control signal, controlling the alternate conduction of the two power switches of the first phase bridge arm of the high-frequency bridge arm module according to the first control signal, controlling the alternate conduction of the two power switches of the second phase bridge arm of the high-frequency bridge arm module according to the second control signal, and controlling the alternate conduction of the two power switches of the third phase bridge arm of the high-frequency bridge arm module according to the third control signal so as to charge the battery.

A second embodiment of the present application provides a charging control system including:

the control signal acquisition module is used for acquiring four-phase control signals, wherein the four-phase control signals comprise high-frequency bridge arm control signals and power-frequency bridge arm control signals, and the high-frequency bridge arm control signals comprise first control signals, second control signals and third control signals which are sequentially different by preset phases;

and the charging execution module is used for controlling the working state of the power frequency bridge arm according to the power frequency bridge arm control signal, controlling the alternate conduction of the two power switches of the first phase bridge arm of the high-frequency bridge arm module according to the first control signal, controlling the alternate conduction of the two power switches of the second phase bridge arm of the high-frequency bridge arm module according to the second control signal, and controlling the alternate conduction of the two power switches of the third phase bridge arm of the high-frequency bridge arm module according to the third control signal so as to charge the battery.

A third embodiment of the present application provides a storage medium storing a computer program that, when executed by a processor, implements the charging control method as provided in the first embodiment of the present application.

The application provides a charging control method, a charging control system and a storage medium thereof, which are applied to a circuit comprising a PFC module, wherein the PFC module comprises a high-frequency bridge arm module and a power-frequency bridge arm, and the high-frequency bridge arm module comprises a three-phase bridge arm; the method comprises the steps of firstly obtaining a four-phase control signal, wherein the four-phase control signal comprises a high-frequency bridge arm control signal and a power frequency bridge arm control signal, the high-frequency bridge arm control signal comprises a first control signal, a second control signal and a third control signal which are sequentially different from each other by a preset phase, then controlling the working state of a power frequency bridge arm according to the power frequency bridge arm control signal, controlling the alternate conduction of two power switches of a first phase bridge arm of a high-frequency bridge arm module according to the first control signal, controlling the alternate conduction of two power switches of a second phase bridge arm of the high-frequency bridge arm module according to the second control signal, and controlling the alternate conduction of two power switches of a third phase bridge arm of the high-frequency bridge arm module according to the third control signal so as to charge a battery. Through the implementation of the application, the first control signal, the second control signal and the third control signal in the three-phase control signals with the sequential phase difference of the pre-phase respectively and correspondingly control the alternate conduction of the power switches in the three-phase bridge arms in the high-frequency bridge arm module so as to charge the battery, and the problems that the current ripple generated by a circuit comprising a multi-phase PFC module is overlarge and electronic components in the circuit are easily damaged in the battery charging technology in the prior art are solved.

Drawings

Fig. 1 shows a block schematic diagram of a PFC module according to a first embodiment of the present application;

fig. 2 shows a circuit topology of a PFC module according to a first embodiment of the present application;

fig. 3 is a schematic step diagram illustrating a charge control method according to a first embodiment of the present application;

fig. 4 is a schematic diagram showing still another step of the charge control method according to the first embodiment of the present application;

fig. 5 is a schematic diagram showing still another step of the charge control method according to the first embodiment of the present application;

fig. 6 is a schematic diagram showing still another step of the charge control method according to the first embodiment of the present application;

fig. 7 is a schematic diagram showing still another step of the charge control method according to the first embodiment of the present application;

FIG. 8 shows a schematic diagram of a three-phase bridge arm pulse signal of a first embodiment of the present application;

FIG. 9 is a schematic circuit flow diagram illustrating a first embodiment of the present application;

FIG. 10 shows a further circuit flow diagram of the first embodiment of the present application;

FIG. 11 shows a further circuit flow diagram of the first embodiment of the present application;

FIG. 12 shows a further circuit flow diagram of the first embodiment of the present application;

FIG. 13 shows a further circuit flow diagram of the first embodiment of the present application;

FIG. 14 shows a further circuit flow diagram of the first embodiment of the present application;

FIG. 15 shows a current schematic of three currents of the first embodiment of the present application;

fig. 16 shows a circuit topology of the first embodiment of the present application.

Detailed Description

In order to make the objects, technical solutions and advantages of the present application more apparent, the present application is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present application and are not intended to limit the present application.

The technical solutions in the embodiments will be described clearly and completely with reference to the drawings in the embodiments, and it is obvious that the described embodiments are some, but not all embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It will be understood that the terms "comprises" and/or "comprising," when used in this specification and the appended claims, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

It is also to be understood that the terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used in this specification and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

It should be further understood that the term "and/or" as used in this specification and the appended claims refers to and includes any and all possible combinations of one or more of the associated listed items.

As used in this specification and the appended claims, the term "if" may be interpreted contextually as "when", "upon" or "in response to a determination" or "in response to a detection". Similarly, the phrase "if it is determined" or "if a [ described condition or event ] is detected" may be interpreted contextually to mean "upon determining" or "in response to determining" or "upon detecting [ described condition or event ]" or "in response to detecting [ described condition or event ]".

In order to explain the technical means of the present application, the following description will be given by way of specific examples.

A first embodiment of the present application provides a charge control method that should be applied to a circuit including a PFC module, as shown in fig. 1, where the PFC module includes a high-frequency leg module 11 and a power-frequency leg 12, and the high-frequency leg module 11 includes a three-phase leg.

In order to more clearly understand the technical content of the present embodiment, the following describes the circuit structure of the PFC module in detail:

as shown in fig. 1, a first end of each of the high-frequency bridge arms 11 and a first end of the power frequency bridge arm 12 are connected together to form a first bus end of the PFC module, a second end of each of the high-frequency bridge arms 11 and a second end of the power frequency bridge arm 12 are connected together to form a second bus end of the PFC module, a midpoint of each of the high-frequency bridge arms 11 is connected to the first end of the ac port 21 through an inductor, a midpoint of the power frequency bridge arm 12 is connected to the second end of the ac port 21, a first end of the battery 22 is connected to the first bus end, and a second end of the battery 22 is connected to the second bus end.

When the PFC module operates and the ac port 21 outputs ac power, the first phase bridge arm 111 and the power frequency bridge arm 12 form a rectifying full bridge, or the second phase bridge arm 112 and the power frequency bridge arm 12 form a rectifying full bridge, or the third phase bridge arm 113 and the power frequency bridge arm 12 form a rectifying full bridge, and the three rectifying full bridges rectify the ac power output from the ac port 21 into dc power to be supplied to the battery 22.

When the PFC module operates and the battery 22 outputs a direct current, the first phase bridge arm 111 and the power frequency bridge arm 12 form an inverter full bridge, or the second phase bridge arm 112 and the power frequency bridge arm 12 form an inverter full bridge, or the third phase bridge arm 113 and the power frequency bridge arm 12 form an inverter full bridge, and the three inverter full bridges invert the direct current output by the battery 22 into an alternating current to be transmitted to the alternating current port 21.

Note that the ac port 21 can output ac power, or ac power can be input to the ac port 21; the battery 22 can output direct current, or direct current can be input to the battery. Meanwhile, the working state that the alternating current is input into the alternating current port 21 and the battery 22 receives the direct current is regarded as a charging mode; the working state that the battery 22 outputs direct current and the alternating current port 21 receives alternating current is regarded as a discharging mode; since the current in the charging mode and the current in the discharging mode are just opposite, and the process of operating the PFC module at the same time is similar, the working state of the PFC module in the charging mode will be described in the present application, and the working state of the PFC module in the discharging mode will not be described herein again.

In addition, when the ac port 21 outputs ac power, the ac port 21 should be connected to ac consumers; when ac power is input to the ac port 21, the ac port 21 should be connected to an ac power supply apparatus. While the battery 22 described in this embodiment is capable of storing or releasing electrical energy.

Further, in order to understand the structure of the PFC module in this embodiment more clearly, as shown in fig. 2, a circuit topology diagram of the PFC module in this embodiment is described in detail.

As shown in fig. 2, in this case, the high-frequency bridge arm module 11 includes a first phase bridge arm 111, a second phase bridge arm 112, and a third phase bridge arm 113, the capacitor module 13 includes C1, and the three inductors are an inductor L1, an inductor L2, and an inductor L3, respectively.

Specifically, the first phase arm 111 includes a first power switch Q1 and a second power switch Q2 connected in series, the second phase arm 112 includes a third power switch Q3 and a fourth power switch Q4 connected in series, the third phase arm 113 includes a fifth power switch Q5 and a sixth power switch Q6 connected in series, the power frequency arm 12 includes a seventh power switch Q7 and an eighth power switch Q8 connected in series, first ends of the first power switch Q1, the third power switch Q3, the fifth power switch Q5 and the seventh power switch Q7 are connected in series to form a first junction end, second ends of the second power switch Q2, the fourth power switch Q4, the sixth power switch Q6 and the eighth power switch Q8 are connected in series to form a second junction end, a common junction point formed by a second end of the first power switch Q1 and a first end of the second power switch Q2 is used as a common junction point of the first phase arm 111, and a midpoint of a second end of the second power switch Q4 of the third phase arm 112 and a fourth power switch Q3 are used as common junction points of the first phase arm 112 and the first power switch Q3 In this regard, a common junction formed by the second terminal of the fifth power switch Q5 and the first terminal of the sixth power switch Q6 serves as a midpoint of the third phase leg 113, a common junction formed by the second terminal of the seventh power switch Q7 and the first terminal of the eighth power switch Q8 serves as a midpoint of the power frequency leg 12, a common junction formed by the first terminal of the inductor L1, the first terminal of the inductor L2, and the first terminal of the inductor L3 is connected to the first terminal of the ac port 21, the second terminal of the inductor L1, and the second terminal of the inductor L2, the second end of the inductor L3 is connected with the midpoint of the first phase bridge arm 111, the midpoint of the second phase bridge arm 112 and the midpoint of the third phase bridge arm 113 in a one-to-one correspondence manner, the midpoint of the power frequency bridge arm 12 is connected with the second end of the ac port 21, the capacitor C1 is connected between the first bus end and the second bus end, the first bus end is connected with the first end of the battery 22, and the second bus end is connected with the second end of the battery 22.

The circuit module of the PFC module applied in the charging control method of the present embodiment is described above, and the circuit topology shown in fig. 2 is taken as an example to describe the circuit structure of the PFC module.

It should be noted that, in order to describe the technical content of the first embodiment of the present application in more detail, the charging control method of the first embodiment will be described below by taking a circuit topology diagram of the PFC module as shown in fig. 2 as an example. In addition, the circuit topology shown in fig. 3 should not be taken as evidence for limiting the first embodiment of the present application, and is only used for explaining the technical solution of the first embodiment of the present application.

Specifically, as shown in fig. 3, the charging control method includes the following steps:

step S1: the method comprises the steps of obtaining four-phase control signals, wherein the four-phase control signals comprise high-frequency bridge arm control signals and power-frequency bridge arm control signals, and the high-frequency bridge arm control signals comprise first control signals, second control signals and third control signals which are sequentially different from each other by preset phases.

In the embodiment, since the vehicle needs to receive the charging command during charging and the state information of the vehicle is in a static state at this time, before charging the battery, it is necessary to confirm the state information of the vehicle and confirm whether the charging command transmitted by the upper computer is received, and when the state information of the vehicle is in the static state and the charging command is received, the charging mode is entered.

In the embodiment, the state information of the vehicle is fed back by a device which can represent the state of the vehicle on the vehicle, such as the motor rotating speed fed back by a motor, and the state information of the vehicle comprises non-static state information and static state information, and the static state information refers to the state of the vehicle when the vehicle is in a locked state after the whole vehicle stops, that is, the motor rotating speed of the vehicle is less than a certain preset rotating speed; similarly, the charging command of the battery is fed back by the battery manager BMS, and the battery manager BMS monitors the state of charge of the battery in real time and feeds back the charging command according to the monitored result.

After receiving the state information of the vehicle and the charging requirement fed back by the battery manager, if the state information of the vehicle is in a non-static state, entering a motor driving mode, wherein the motor driving mode is the same as the existing motor driving principle, and reference may be made to the prior art specifically, which is not repeated here; when the state information of the vehicle is in a static state and the charging requirement fed back by the battery manager is charging, it indicates that the battery of the vehicle needs to be charged at this time, so the charging mode is entered, and the charging mode is an alternating current charging mode, and the alternating current charging mode includes, but is not limited to, single-phase alternating current charging and three-phase alternating current charging.

After entering the charging mode, the four-phase control signal can be obtained at this time, and the states of the two power switches of each phase bridge arm in the high-frequency bridge arm module 11 are controlled according to the obtained four-phase control signal, and the four-phase control signal is also used for controlling the states of the two power switches of the power frequency bridge arm 12, so as to charge the battery 22; it should be noted that, in the present embodiment, the preset phase may be set according to needs, and is not limited specifically here.

In some examples, the delay between the first control signal, the second control signal, and the third control signal is T/3 in sequence, where T represents a period in which the power switches of the three-phase bridge arms are turned on and off.

Further, as an implementation manner of this embodiment, as shown in fig. 4, step S1 specifically includes the following contents:

s11: acquiring a rotor angle signal, a three-phase charging current, a preset quadrature axis current, a preset direct axis current, a feedforward voltage and a bus side direct current voltage of a motor in a charging mode;

s12: acquiring a three-phase modulation signal according to the rotor angle signal, the three-phase charging current, the preset alternating current, the preset direct current, the feedforward voltage and the bus side direct current voltage;

s13: and acquiring a preset carrier signal, and acquiring a high-frequency bridge arm control signal with a preset phase difference according to the carrier signal and the three-phase modulation signal.

In the embodiment, after entering the charging mode, corresponding parameter information needs to be acquired in the charging mode to control the charging power in the charging process. The parameter information in the charging mode includes, but is not limited to, a rotor angle signal of the motor in the charging mode, a three-phase charging current, a preset quadrature axis current, a preset direct axis current, a feed-forward voltage, and a bus-side direct current voltage.

Specifically, the rotor angle signal is an included angle between a rotor magnetic field of the motor and a phase axis of the stator a in the charging mode, and the rotor angle signal may be fed back after being acquired by an angle sensor, or may be calculated from a current of the three-phase ac motor, and is not specifically limited herein; in addition, the three-phase charging current refers to a three-phase current of the motor during charging, and the preset quadrature axis current and the preset direct axis current are the quadrature axis current and the direct axis current which are preset according to needs.

Further, as an implementation manner of this embodiment, as shown in fig. 5, the step S12 specifically includes the following steps:

step S121: acquiring a first modulation signal according to the rotor angle signal, the three-phase charging current, the preset alternating-axis current, the preset direct-axis current and the bus side direct-current voltage;

step S122: acquiring a second modulation signal according to the three-phase charging current and the feedforward voltage;

step S123: and acquiring a three-phase modulation signal according to the first modulation signal and the second modulation signal.

In this embodiment, in order to increase the charging power of the battery 22 during the charging process, after the rotor angle signal, the three-phase charging current, the preset quadrature axis current, the preset direct axis current, and the bus-side direct current voltage of the motor in the charging mode are obtained, a first modulation signal is obtained according to the above parameters, the first modulation signal is a pulse width modulation signal obtained by controlling a differential mode current portion in a winding of the motor, and the pulse width modulation signal is a three-phase pulse width modulation signal.

Further, in order to increase the charging power of the battery 22 during the charging process, in addition to the first modulation signal, a second modulation signal is also required to be obtained according to the three-phase charging current and the feedforward voltage, where the second modulation signal is a pulse modulation signal obtained by performing zero-sequence current extraction on the three-phase charging current of the motor and then controlling the part of the common mode current.

After the first modulation signal and the second modulation signal are obtained, corresponding operation can be carried out on the first modulation signal and the second modulation signal so as to obtain a three-phase modulation signal; in the present embodiment, since the first modulation signal is a three-phase pulse width modulation signal, the three-phase modulation signal obtained by calculating the first modulation signal and the second modulation signal is a three-phase pulse width modulation signal in the same manner.

In the embodiment, the first modulation signal is obtained according to the rotor angle signal, the three-phase charging current, the preset quadrature axis current, the preset direct axis current and the bus side direct current voltage, the second modulation signal is obtained according to the three-phase charging current and the feedforward voltage, and then the three-phase modulation signal is obtained according to the first modulation signal and the second modulation signal after the first modulation signal and the second modulation signal are obtained, so that the three-phase pulse width modulation signal for finally controlling the high-frequency bridge arm module 11 is obtained by using the three-phase modulation signal, and thus the charging power of the battery 22 in the charging process is adjusted, and the purpose of improving the charging power is achieved.

Further, as an implementation manner of this embodiment, as shown in fig. 6, the step S121 further includes the following steps:

step S1211: carrying out coordinate transformation on the three-phase charging current according to the rotor angle signal to obtain two-phase charging current;

step S1212: after the difference is made between the two-phase charging current and the preset quadrature-axis current and the preset direct-axis current, quadrature-axis voltage and direct-axis voltage are obtained through current regulation;

step S1213: and acquiring a first modulation signal according to the rotor angle signal, the alternating-current shaft voltage, the direct-current shaft voltage and the bus side direct-current voltage.

In the embodiment, the specific principle of performing coordinate transformation on the three-phase charging current according to the rotor angle signal to obtain the two-phase charging current is the same as that of the prior art, and reference may be made to the prior art specifically, which is not described herein again.

After the two-phase charging current is obtained, the two-phase charging current, the preset quadrature-axis current and the preset direct-axis current may be subjected to difference processing, and quadrature-axis voltage and direct-axis voltage are obtained through current regulation, where the current regulation may be implemented by a proportional-integral regulation method, but it may be understood by those skilled in the art that other methods may also be implemented, such as fuzzy regulation or intelligent regulation, and no specific limitation is made here. After the quadrature axis voltage and the direct axis voltage are obtained, a first modulation signal can be obtained according to the rotor angle signal, the quadrature axis voltage, the direct axis voltage and the bus side direct current voltage.

It should be noted that, in the embodiment, in order to prevent the motor from outputting the torque, the values of the preset quadrature axis current and the preset direct axis current may be set so that the motor output torque is zero. Specifically, in the present embodiment, the preset quadrature axis current may be set to be zero, that is, as long as the preset quadrature axis current is zero, the motor does not output torque; preferably, the preset direct-axis current and the preset quadrature-axis current can be set to be zero at the same time, so that the output torque of the motor is zero, and the purpose of inhibiting the output torque of the motor is achieved.

In addition, in the embodiment, the current three-phase alternating current charging current in the stationary coordinate system is converted into two-phase charging current in the synchronous rotating coordinate system, namely the direct-axis current and the quadrature-axis current, by the three-phase charging current according to the motor rotor angle signal, so that when the obtained two-phase charging current is different between the preset quadrature-axis current and the preset direct-axis current, the standard in the same coordinate system can be used, and the accuracy in the charging power adjusting process is further improved.

Further, as an implementation manner of this embodiment, as shown in fig. 7, the step S122 specifically includes the following steps:

step S1221: extracting zero-sequence current from the three-phase charging current;

step S1222: after the zero sequence current is differed from the given charging current, the modulation voltage is obtained through current regulation; wherein, the given charging current is obtained by analyzing a charging instruction;

step S1223: and after summing the modulation voltage and the feedforward voltage, acquiring a second modulation signal through voltage modulation.

In the embodiment, the zero-sequence current is a common-mode current flowing through a motor winding, and for the purpose of controlling a charging current of the motor winding, the current is zero before charging is started, and when a charging power command or a charging current command is received, the current is gradually increased until a target current value is reached, so that after a charging mode is entered, in order to improve the charging power, the zero-sequence current needs to be extracted from three-phase charging currents of the motor in the charging mode, and it should be noted that the extracted zero-sequence current is not zero.

After the zero sequence current is extracted, performing difference processing according to the zero sequence current and the given charging current, and further obtaining modulation voltage through current regulation so as to obtain a second modulation signal according to the modulation voltage and feedforward voltage; it should be noted that, in this embodiment, the given charging current is obtained according to the charging command fed back by the battery manager BMS, that is, after receiving the charging command of the power battery fed back by the battery manager BMS, the charging command can be analyzed to obtain the required charging current or charging power.

In this embodiment, a zero sequence current is extracted from the three-phase charging current, and then a modulation voltage is obtained according to the zero sequence current, so as to obtain a second modulation signal according to the modulation voltage, so that when a three-phase control signal for finally controlling the three-phase bridge arm of the high-frequency bridge arm module 11 is obtained according to the second modulation signal, the current value in the charging process can be effectively adjusted according to the obtained three-phase control signal.

Further, as an implementation manner of this embodiment, the step S123 further includes the following steps:

and adding the duty ratio of the second modulation signal and the duty ratio of the first modulation signal to obtain a three-phase modulation signal.

In the embodiment, since the first modulation signal is a three-phase pulse width modulation signal obtained by controlling a differential mode current portion in a motor winding, and the second modulation signal is a modulation signal obtained by controlling a common mode current portion in the motor winding, the three-phase modulation signal obtained by adding the duty ratio of the second modulation signal to the duty ratio of the first modulation signal is a modulation signal obtained by controlling a differential mode current and a common mode current in the motor winding, and the three-phase modulation signal is used to obtain a final three-phase control signal, so that when the high-frequency bridge arm module 11 is controlled, the adjustment of the charging power is completed, the rotation of the motor can be suppressed, and the occurrence of unexpected vehicle vibration in the charging process can be prevented.

Further, in the embodiment, when obtaining three-phase control signals with a preset phase difference according to a carrier signal and a three-phase modulation signal, carrier phase error may be selected, and modulated wave phase error may also be selected, that is, phase error adjustment may be performed on the three-phase modulation signal through the carrier signal, or the three-phase modulation signal itself may be a phase error signal, and the following process will be described in detail as follows:

when the carrier phase error method is adopted, the carrier signal includes a first phase carrier signal, a second phase carrier signal and a third phase carrier signal, a phase difference between the first phase carrier signal and the second phase carrier signal is a preset angle, the three-phase modulation signal includes a first phase modulation signal, a second phase modulation signal and a third phase modulation signal, and obtaining a three-phase control signal with a preset phase difference according to the carrier signal and the three-phase modulation signal specifically includes:

and superposing the first phase carrier signal and the first phase modulation signal, superposing the second phase carrier signal and the second phase modulation signal, and superposing the third phase carrier signal and the third phase modulation signal to obtain a three-phase control signal.

In the embodiment, the carrier signal is preferably a triangular carrier signal, but it is understood by those skilled in the art that the carrier signal may also be other carrier signals that can generate a desired pulse width sequence, such as a sawtooth carrier signal, and is not limited herein; in addition, the value of the preset angle is preferably 120 degrees, which can reduce ripple current on the dc bus side and the N line to the greatest extent, but it can be understood by those skilled in the art that the value of the preset angle may also be other values, for example, 60 degrees, and the present application is not limited specifically.

Further, when the three-phase carrier signal is respectively superposed with the three-phase modulation signal, in order to superpose the differential mode current control and the common mode current control, the duty ratio of the three-phase control signal obtained after superposition is the sum of the common duty ratios of the two, that is, the obtained three-phase control signal with the difference of the preset phase is the duty ratio required by the common mode current output and is simultaneously added to the duty ratio required by the three-phase differential mode current control, so that when the obtained three-phase control signal respectively controls the three-phase bridge arm of the high-frequency bridge arm module 11, the three-phase staggered control of the three-phase bridge arm can be realized, and thus, the ripple waves on the direct current side can be reduced, and the charging power can be effectively improved.

Further, as an implementation manner of this embodiment, when the method of modulating the wave phase error is adopted, the carrier signal includes a first phase carrier signal, a second phase carrier signal, and a third phase carrier signal, the three phase modulation signal includes a first phase modulation signal, a second phase modulation signal, and a third phase modulation signal, and a phase of the first phase modulation signal, a phase of the second phase modulation signal, and a phase of the third phase modulation signal all differ by a preset angle; the method for acquiring the three-phase control signal with the preset phase difference according to the carrier signal and the three-phase modulation signal specifically comprises the following steps:

In this embodiment, the specific implementation process of the method using modulated wave phase shifting is the same as that of the method using carrier phase shifting, so that the specific principle of the method using modulated wave phase shifting may refer to the related description of the method using carrier phase shifting, and is not described herein again.

Step S2: the working state of the industrial frequency bridge arm 12 is controlled according to the industrial frequency bridge arm control signal, the alternate conduction of the two power switches of the first phase bridge arm 111 of the high-frequency bridge arm module 11 is controlled according to the first control signal, the alternate conduction of the two power switches of the second phase bridge arm 112 of the high-frequency bridge arm module 11 is controlled according to the second control signal, and the alternate conduction of the two power switches of the third phase bridge arm 113 of the high-frequency bridge arm module 11 is controlled according to the third control signal, so that the battery 22 is charged.

The three-phase bridge arm in the high-frequency bridge arm module 11 is respectively matched with the power-frequency bridge arm 12 to convert the alternating current output by the alternating current port 21 into direct current and realize power factor correction, and meanwhile, because delay is arranged among the first control signal, the second control signal and the third control signal, current ripples generated by the PFC module are reduced.

In this embodiment, the first control signal, the second control signal, and the third control signal in the three-phase control signals sequentially differing by the pre-phase respectively and correspondingly control the alternate conduction of the two power switches in the three-phase bridge arm in the high-frequency bridge arm module 11, so as to charge the battery, thereby achieving the purposes of reducing the dc side ripple and improving the charging power.

Further, as an implementation manner of this embodiment, the voltage of the direct current output by the output end of the PFC module is controlled by controlling the duty ratio of each phase of the three-phase bridge arm in the high-frequency bridge arm module 11; the duty ratio represents the ratio of the on-time of one power switch of each phase of bridge arm to the on-off period of one power switch in the three-phase bridge arms.

It should be noted that the larger the control duty ratio is, the larger the voltage of the direct current output by the high-frequency bridge arm module 11 and the power-frequency bridge arm 12 is; in addition, in this embodiment, when the PFC module is in the charging mode, one of the high-frequency bridge arms in the high-frequency bridge arm module 11 may output a direct current, or two of the high-frequency bridge arms may output a direct current, or three-phase bridge arms may output a direct current at the same time.

Taking the schematic diagram of the bridge arm pulse signals shown in fig. 8 as an example, at this time, the duty ratio of each phase of the bridge arm is 50%, at this time, the time for turning on and off a power switch in one phase of the bridge arm is equal, and the delay between the first control signal and the second control signal, and between the second control signal and the third control signal is T/3.

In some examples, the phase difference between the nth high frequency leg control signal and the (n-1) th high frequency leg control signal is 360/m degrees; wherein n is more than or equal to 2 and is a positive integer.

In order to more clearly understand the technical content of this embodiment, a description is given below of a control method for controlling power switches of three-phase arms in the high-frequency arm module 11 in an interleaved manner, by taking the exemplary circuit diagram shown in fig. 2 as an example:

a first switching mode: as shown in fig. 9, the second power switch Q2 is controlled to be turned on at D × T, the eighth power switch is normally turned on, the current output from the ac port 21 flows through the inductor L1, the second power switch Q2, and flows back to the ac port 21 through the eighth power switch Q8, at this time, the ac port 21, the inductor L1, the second power switch Q2, and the eighth power switch Q8 form an ac energy storage circuit, the inductor L1 completes energy storage and voltage boost, and the current through the inductor L1 increases. Where D denotes the duty cycle and T denotes the on/off period of each power switch in the high-frequency arm module 11.

And a second switching mode: as shown in fig. 10, the fourth power switch Q4 is controlled to be turned on at D × T, the eighth power switch is normally turned on, while the second power switch maintains the state of the first switching mode, the current passing through the inductor L1 continues to increase, the current output from the ac port 21 passes through the inductor L2, flows through the fourth power switch Q4, and flows back to the ac port 21 through the eighth power switch Q8, at this time, the ac port 21, the inductor L2, the fourth power switch Q4, and the eighth power switch Q8 form an ac energy storage circuit, the inductor L2 completes energy storage and voltage boosting, and the current passing through the inductor L2 increases.

A third switching mode: as shown in fig. 11, the fourth power switch Q4 is controlled to maintain the state of the second switching mode, the second power switch Q2 is controlled to be turned off, the first power switch Q1 is turned on (1-D) × T, at this time, the current output by the ac outlet 21 flows back to the ac outlet 21 through the inductor L1, the first power switch Q1, the capacitor C1 and the eighth power switch Q8, at this time, the ac outlet 21, the inductor L1, the first power switch Q1, the capacitor C1 and the eighth power switch Q8 form an ac discharging loop, the inductor L1 completes the energy storage discharge, and the current through the inductor L1 is reduced.

And a fourth switching mode: as shown in fig. 12, the sixth power switch Q6 is controlled to be turned on, D × T, the fourth power switch Q4 maintains the state of the second switching mode, the second power switch Q2 maintains the state of the third switching mode, the current passing through the inductor L1 continuously decreases, the current passing through the inductor L2 continuously increases, the current output from the ac port 21 passes through the inductor L3, the sixth power switch Q6, and the eighth power switch Q8 and flows back to the ac port 21, at this time, the ac port 21, the inductor L3, the sixth power switch Q6, and the eighth power switch Q8 form an ac energy storage loop, the inductor L3 completes energy storage, and the current passing through the inductor L3 increases.

A fifth switching mode: as shown in fig. 13, the fourth power switch Q4 is controlled to be turned off, the third power switch Q3 is turned on (1-D) × T, the sixth power switch Q6 maintains the state of the switch module four, the second power switch Q2 maintains the state of the switch mode three, the current passing through the inductor L3 continues to increase, the current passing through the inductor L1 continues to decrease, at this time, the current output from the ac port 21 flows back to the ac port 21 through the inductor L2, the third power switch Q3, the capacitor C1, and the eighth power switch Q8, at this time, the ac port 21, the inductor L2, the third power switch Q3, the capacitor C1, and the eighth power switch Q8 form an ac energy release loop, the inductor L2 completes energy storage release, and the current passing through the inductor L2 decreases.

A switching mode six: as shown in fig. 14, the first power switch Q1 is controlled to be turned off, the second power switch Q2 is turned on at D × T, the fourth power switch keeps in the fifth switching mode, the sixth power switch keeps in the fourth switching mode, the current passing through the inductor L2 continuously decreases, the current passing through the inductor L3 continuously increases, the current output from the ac port 21 passes through the inductor L1, flows through the second power switch Q2, and flows back to the ac port 21 through the eighth power switch Q8, at this time, the ac port 21, the inductor L1, the second power switch Q2, and the eighth power switch Q8 form an ac energy storage circuit, the inductor L1 completes energy storage and voltage boost, and the current passing through the inductor L1 increases.

Through the cyclic operation of the first switching mode to the sixth switching mode, the capacitor C1 is continuously charged, and the voltage across the capacitor C1 is maintained stable. In addition, the switching patterns one to six only describe the operating states of the three-phase bridge arm when the current output by the ac port 21 is in the positive half period, and since the operating states of the three-phase bridge arm when the current output by the ac port 21 is in the negative half period are opposite to the operating states of the three-phase bridge arm in the positive half period, the operating principles are the same, and thus the description is omitted here.

It should be noted that the capacitor C1 can filter the voltage input to the battery 22, so as to reduce the external interference to the charging circuit.

In this embodiment, only the case that the high-frequency bridge arm module 11 includes a three-phase bridge arm is described, and when the high-frequency bridge arm module 11 includes a six-phase bridge arm or a nine-phase bridge arm, the method for controlling charging provided in this embodiment can also achieve staggered control of the multi-phase bridge arm, and reduce current ripples.

In order to more clearly understand the technical effects of the present embodiment, taking the current ripples generated by the PFC module under the conditions of the first switching mode to the sixth switching mode as an example, as shown in fig. 15, when an interleaved control method is adopted, the amplitudes of the currents passing through the inductors are staggered, and the total current generated by the three inductors is small; however, with the existing synchronous control method, because the amplitudes of the inductors change synchronously, the currents passing through the three inductors reach the maximum value and the minimum value at the same time, the total current change amplitude generated by the three inductors is large, and meanwhile, the difference value between the maximum value and the minimum value is large, which is not beneficial to stabilizing the control circuit. Therefore, by adopting the staggered charging control method, the current ripple generated by the PFC module is greatly reduced, and the electronic elements in the circuit are powerfully protected.

In the present embodiment, the charge control method can also be applied to a circuit topology shown in fig. 16, in which ac power can be output or input from the ac port 21 and dc power can be output or input from the battery 22.

In the circuit topology diagram of the embodiment, the electric control module is multiplexed as the high-frequency bridge arm module 11, and at the same time, the windings of the motor are multiplexed as the inductor L1, the inductor L2 and the inductor L3, so that the integration level of the electric drive system is improved, and the cost of the electric drive system is reduced.

Further, a second embodiment of the present application provides a charging control system including:

the control signal acquisition module is used for acquiring four-phase control signals, wherein the four-phase control signals comprise high-frequency bridge arm control signals and power-frequency bridge arm 12 control signals, and the high-frequency bridge arm control signals comprise a first control signal, a second control signal and a third control signal which sequentially differ by a preset phase;

and the charging execution module is configured to control the operating state of the power frequency bridge arm 12 according to the control signal of the power frequency bridge arm 12, control the two power switches of the first phase bridge arm 111 of the high-frequency bridge arm module 11 to be alternately turned on according to the first control signal, control the two power switches of the second phase bridge arm 112 of the high-frequency bridge arm module 11 to be alternately turned on according to the second control signal, and control the two power switches of the third phase bridge arm 113 of the high-frequency bridge arm module 11 to be alternately turned on according to the third control signal, so as to charge the battery 22.

Further, as an implementation manner of the present embodiment, the charging control system further includes:

the first acquisition module is used for acquiring a rotor angle signal, a three-phase charging current, a preset quadrature axis current, a preset direct axis current, a feedforward voltage and a bus side direct current voltage of the motor in a charging mode;

the second acquisition module is used for acquiring a three-phase modulation signal according to the rotor angle signal, the three-phase charging current, the preset alternating-current shaft current, the preset direct-current shaft current, the feedforward voltage and the bus-side direct-current voltage;

and the third acquisition module is used for acquiring a preset carrier signal and acquiring a high-frequency bridge arm control signal with a preset phase difference according to the carrier signal and the three-phase modulation signal.

the fourth acquisition module is used for acquiring a first modulation signal according to the rotor angle signal, the three-phase charging current, the preset alternating-current shaft current, the preset direct-current shaft current and the bus side direct-current voltage;

the fifth acquisition module is used for acquiring a second modulation signal according to the three-phase charging current and the feedforward voltage;

and the sixth acquisition module is used for acquiring the three-phase modulation signal according to the first modulation signal and the second modulation signal.

the seventh obtaining module is used for carrying out coordinate transformation on the three-phase charging current according to the rotor angle signal so as to obtain two-phase charging current;

the eighth acquisition module is used for obtaining quadrature-axis voltage and direct-axis voltage through current regulation after the difference is made between the two-phase charging current and the preset quadrature-axis current and the preset direct-axis current;

and the ninth acquisition module is used for acquiring a first modulation signal according to the rotor angle signal, the alternating-current-axis voltage, the direct-current-axis voltage and the bus-side direct-current voltage.

and the torque setting module is used for setting that the preset quadrature axis current and the preset direct axis current are zero so as to enable the output torque to be zero.

the extraction module is used for extracting zero sequence current from the three-phase charging current;

the analysis module is used for obtaining modulation voltage through current regulation after the zero sequence current and the given charging current are subjected to difference; wherein, the given charging current is obtained by analyzing a charging instruction;

and the tenth acquisition module is used for acquiring a second modulation signal through voltage modulation after summing the modulation voltage and the feedforward voltage.

and an eleventh acquiring module, configured to add the duty cycle of the second modulation signal and the duty cycle of the first modulation signal to acquire a three-phase modulation signal.

The preset angle module is used for enabling carrier signals to comprise a first phase carrier signal, a second phase carrier signal and a third phase carrier signal, enabling the three phase modulation signals to comprise a first phase modulation signal, a second phase modulation signal and a third phase modulation signal, and enabling the phase of the first phase carrier signal, the phase of the second phase carrier signal and the phase of the third phase carrier signal to sequentially differ by a preset angle; or the phase of the first phase modulation signal, the phase of the second phase modulation signal and the phase of the third phase modulation signal sequentially differ by a preset angle;

and the twelfth acquisition module is used for superposing the first phase carrier signal and the first phase modulation signal, superposing the second phase carrier signal and the second phase modulation signal, and superposing the third phase carrier signal and the third phase modulation signal to acquire the three-phase control signal.

Since the specific definition of the charging control system in the present application can be referred to the definition of the charging control method in the foregoing, detailed description is omitted here. The modules in the charging control system may be wholly or partially implemented by software, hardware, or a combination thereof. The modules can be embedded in a hardware form or independent from a processor in the computer device, and can also be stored in a memory in the computer device in a software form, so that the processor can call and execute operations corresponding to the modules.

The storage medium in the present embodiment stores a computer program, and the computer program realizes the steps of the charging control method in the first embodiment of the present application when executed by the processor. Alternatively, the computer program is executed by the processor to implement the functions of the modules of the charging control system in the second embodiment of the present application, and is not described herein again to avoid repetition.

It will be understood by those skilled in the art that all or part of the processes of the methods of the embodiments described above may be implemented by hardware instructions of a computer program, which may be stored in a non-volatile computer-readable storage medium, and when executed, may include the processes of the embodiments of the methods described above. Any reference to memory, storage, database, or other medium used in the embodiments provided herein may include non-volatile and/or volatile memory, among others. Non-volatile memory can include read-only memory (ROM), Programmable ROM (PROM), Electrically Programmable ROM (EPROM), Electrically Erasable Programmable ROM (EEPROM), or flash memory. Volatile memory can include Random Access Memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in a variety of forms such as Static RAM (SRAM), Dynamic RAM (DRAM), Synchronous DRAM (SDRAM), Double Data Rate SDRAM (DDRSDRAM), Enhanced SDRAM (ESDRAM), Synchronous Link DRAM (SLDRAM), Rambus Direct RAM (RDRAM), direct bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

It will be apparent to those skilled in the art that, for convenience and brevity of description, only the above-mentioned division of the functional units and modules is illustrated, and in practical applications, the above-mentioned function distribution may be performed by different functional units and modules according to needs, that is, the internal structure of the apparatus is divided into different functional units or modules to perform all or part of the above-mentioned functions.

The above-mentioned embodiments are only used for illustrating the technical solutions of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the embodiments of the present invention, and they should be construed as being included therein.

Claims

1. A charging control method is applied to a circuit containing a PFC module, the PFC module comprises a high-frequency bridge arm module and a power-frequency bridge arm, the high-frequency bridge arm module comprises a three-phase bridge arm, and the method is characterized by comprising the following steps:

acquiring four-phase control signals, wherein the four-phase control signals comprise high-frequency bridge arm control signals and power-frequency bridge arm control signals, and the high-frequency bridge arm control signals comprise first control signals, second control signals and third control signals which are sequentially different by preset phases;

2. The charging control method according to claim 1, wherein the step of obtaining the high-frequency bridge arm control signal includes:

acquiring a rotor angle signal, three-phase charging current, preset quadrature axis current, preset direct axis current, feedforward voltage and bus side direct current voltage of a motor in a charging mode;

acquiring a three-phase modulation signal according to the rotor angle signal, the three-phase charging current, the preset alternating-current shaft current, the preset direct-current shaft current, the feedforward voltage and the bus side direct-current voltage;

and acquiring a preset carrier signal, and acquiring a high-frequency bridge arm control signal with a preset phase difference according to the carrier signal and the three-phase modulation signal.

3. The charge control method according to claim 2, wherein the obtaining a three-phase modulation signal from the rotor angle signal, the three-phase charging current, the preset quadrature-axis current, the preset direct-axis current, the feed-forward voltage, and the bus-side direct-current voltage comprises:

acquiring a first modulation signal according to the rotor angle signal, the three-phase charging current, the preset quadrature axis current, the preset direct axis current and the bus side direct current voltage;

acquiring a second modulation signal according to the three-phase charging current and the feedforward voltage;

and acquiring the three-phase modulation signal according to the first modulation signal and the second modulation signal.

4. The charge control method according to claim 3, wherein the obtaining a first modulation signal according to the rotor angle signal, the three-phase charging current, the preset quadrature-axis current, the preset direct-axis current, and the bus-side direct-current voltage comprises:

performing coordinate transformation on the three-phase charging current according to the rotor angle signal to obtain two-phase charging current;

after the two-phase charging current is differenced with the preset quadrature-axis current and the preset direct-axis current, quadrature-axis voltage and direct-axis voltage are obtained through current regulation;

and acquiring the first modulation signal according to the rotor angle signal, the quadrature axis voltage, the direct axis voltage and the bus side direct current voltage.

5. The charge control method according to any one of claims 2 to 4, characterized by further comprising:

and setting the preset quadrature axis current and the preset direct axis current to be zero so as to enable the output torque to be zero.

6. The charge control method of claim 3, wherein the step of deriving a second modulation signal based on the three-phase charging current and the feed-forward voltage comprises:

extracting zero sequence current from the three-phase charging current;

after the zero sequence current is differed from the given charging current, the modulation voltage is obtained through current regulation; wherein the given charging current is obtained by analyzing a charging instruction;

and after summing the modulation voltage and the feedforward voltage, acquiring the second modulation signal through voltage modulation.

7. The charge control method according to claim 3, wherein the step of obtaining the three-phase modulation signal from the first modulation signal and the second modulation signal comprises:

and adding the duty ratio of the second modulation signal and the duty ratio of the first modulation signal to obtain the three-phase modulation signal.

8. The charge control method according to claim 2, wherein the carrier signal includes a first phase carrier signal, a second phase carrier signal, and a third phase carrier signal, the three phase modulation signals include a first phase modulation signal, a second phase modulation signal, and a third phase modulation signal, and a phase of the first phase carrier signal, a phase of the second phase carrier signal, and a phase of the third phase carrier signal sequentially differ by a preset angle; or the phase of the first phase modulation signal, the phase of the second phase modulation signal and the phase of the third phase modulation signal sequentially differ by a preset angle;

the step of obtaining the high-frequency bridge arm control signal with a preset phase difference according to the carrier signal and the three-phase modulation signal comprises the following steps:

and superposing the first phase carrier signal and the first phase modulation signal, superposing the second phase carrier signal and the second phase modulation signal, and superposing the third phase carrier signal and the third phase modulation signal to obtain the three-phase modulation signal.

9. A charge control system, characterized by comprising:

the control signal acquisition module is used for acquiring four-phase control signals, wherein the four-phase control signals comprise high-frequency bridge arm control signals and power-frequency bridge arm control signals, and the high-frequency bridge arm control signals comprise a first control signal, a second control signal and a third control signal which sequentially differ by a preset phase;

and the charging execution module is used for controlling the working state of the power frequency bridge arm according to the power frequency bridge arm control signal, controlling the two power switches of a first phase bridge arm of the high-frequency bridge arm module to be alternately conducted according to the first control signal, controlling the two power switches of a second phase bridge arm of the high-frequency bridge arm module to be alternately conducted according to the second control signal, and controlling the two power switches of a third phase bridge arm of the high-frequency bridge arm module to be alternately conducted according to the third control signal so as to charge the battery.

10. A storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the charging control method according to any one of claims 1 to 8.