Charging system and method of electric vehicle and electric vehicle

Abstract

According to the charging system and method of the electric vehicle and the electric vehicle provided by the embodiment of the invention, the armature winding in the automobile engine is used for replacing an additionally mounted inductance element for boosting and energy storage, the number of elements required by the automobile charging system is reduced, and the production and maintenance cost is reduced. The charging system of the electric vehicle comprises a control module used for sending a first control signal to a direct current charging module and an inversion module; the direct current charging module is used for charging the power battery in response to the first control signal; the inversion module is used for responding to the first control signal and switching to a first conduction mode; the driving motor is used for storing energy by using an internal armature winding when being electrified; the control module is also used for sending a second control signal to the inversion module; the inversion module is also used for responding to a second control signal and switching to a second conduction mode; and the driving motor is also used for boosting and charging the power battery by using the armature winding.

Description

[Technical field]

[0001] The embodiments of the present application relate to the field of vehicle technology, and in particular, to a charging system and method for an electric vehicle and an electric vehicle. [Background technology]

[0002] With the popularization of electric vehicle fast charging technology, a car charging system that uses high-voltage DC charging technology to achieve fast charging has been widely used in various vehicles. This charging system adds additional inductance and alternately performs boosting and energy storage and discharge and freewheeling with the help of the inductance to meet the demand for high-voltage fast charging of power batteries. However, since this car charging system requires additional inductance components to perform boosting and energy storage normally, the production cost and maintenance cost of the charging system have increased. [Summary of the invention]

[0003] The embodiments of the present application provide a charging system, method and electric vehicle for an electric vehicle, which uses the armature winding inside the automobile engine to replace the additionally installed inductive element for boosting and storing energy, thereby reducing the number of components required for the automobile charging system and lowering production and maintenance costs.

[0004] In a first aspect, an embodiment of the present application provides a charging system for an electric vehicle, the system comprising: a control module, a power battery, a drive motor, an inverter module and a DC charging module; the control module is respectively connected to a first input terminal and a second input terminal of the inverter module, an input terminal of the DC charging module and a signal output terminal of a battery management system; a first output terminal of the DC charging module is connected to a positive electrode of the power battery, and a second output terminal of the DC charging module is connected to a negative electrode of the power battery; a first DC terminal of the inverter module is connected to a first output terminal of the DC charging module, a second DC terminal of the inverter module is connected to a second output terminal of the DC charging module, an AC terminal of the inverter module is connected to a first port of the drive motor, and a second port of the drive motor is connected to a second output terminal of the DC charging module;

[0005] The control module is configured to send a first control signal to the DC charging module and the first input terminal of the inverter module when receiving a charging request from the battery management system;

[0006] The DC charging module is used to charge the power battery in response to the first control signal;

[0007] The inverter module is used to switch to a first conduction mode in response to the first control signal, and the first conduction mode is used to indicate that the first DC terminal and the AC terminal of the inverter module are connected;

[0008] The drive motor is used to store energy using the internal armature winding when powered on;

[0009] The control module is further configured to send a second control signal to the first input terminal and the second input terminal of the inverter module at a first set time interval after sending the first control signal;

[0010] The inverter module is further configured to switch to a second conduction mode in response to the second control signal, wherein the second conduction mode is configured to indicate that the first DC terminal, the second DC terminal, and the AC terminal of the inverter module are connected;

[0011] The drive motor is also used to boost and charge the power battery using the magnetic field energy stored in the armature winding.

[0012] In the embodiment of the present application, by changing the conduction mode of the inverter module, the armature winding inside the drive motor is used to boost and charge the power battery, thereby integrating the energy storage inductor required for boost charging into the existing components of the charging system, simplifying the inductor and supporting components that need to be additionally installed, and reducing the cost and maintenance cost of the charging system.

[0013] Optionally, the inverter module includes at least a first upper bridge arm unit and a first lower bridge arm unit, wherein the first port of the first upper bridge arm unit is connected to the first output end of the DC charging module, the second port of the first upper bridge arm unit is connected to the first port of the first lower bridge arm unit, and the second port of the first lower bridge arm unit is connected to the second output end of the DC charging module; the first upper bridge arm unit and the first lower bridge arm unit are both kept in a normally off state;

[0014] The armature winding of the drive motor at least includes a first armature inductor and a second armature inductor, the same-name end of the first armature inductor is connected to the same-name end of the second armature inductor, the opposite-name end of the first armature inductor is connected to the second port of the first upper bridge arm unit, and the opposite-name end of the second armature inductor is connected to the second output end of the DC charging module;

[0015] The control module is at least connected to the control end of the first upper bridge arm unit;

[0016] The first upper bridge arm unit is configured to be turned on in response to the first control signal;

[0017] The first armature inductor is used to store energy when powered on.

[0018] In the embodiment of the present application, the first upper bridge arm unit is controlled to be turned on so that the first armature inductor and the second armature inductor are energized and start storing energy, thereby providing preparation conditions for the next step of multiplexing the drive motor to replace the external inductor for boost charging.

[0019] Optionally, the control module is at least further connected to the control end of the first lower bridge arm unit, and the first upper bridge arm unit is further used to shut down in response to the second control signal;

[0020] The first lower bridge arm unit is configured to be turned on in response to the second control signal;

[0021] The first armature inductor and the second armature inductor are also used to boost and charge the power battery by utilizing the magnetic field energy stored inside when power is stopped;

[0022] The control module is further configured to send a third control signal to the first upper bridge arm unit and the first lower bridge arm unit at a second set time interval after sending the second control signal;

[0023] The first upper bridge arm unit is further configured to be turned on in response to the third control signal;

[0024] The first lower bridge arm unit is further configured to be shut down in response to the third control signal;

[0025] The first armature inductance and the second armature inductance are also used to store energy when powered on.

[0026] In the embodiment of the present application, after a certain amount of magnetic field energy for maintaining current is stored in the first armature inductance and the second armature inductance, the conduction mode is changed to charge the power battery, and after the energy storage of the first armature inductance and the second armature inductance is exhausted, the conduction mode is changed again to store energy again, thereby realizing the alternating execution of energy storage and boost charging using the first armature inductance and the second armature inductance, and ensuring the reliability of using the armature inductance instead of the external inductance for charging.

[0027] Optionally, the system further includes: a first switch and a first capacitor, wherein a first port of the first switch is connected to a first port of the first capacitor, and a second port of the first capacitor is connected to the opposite end of the second armature inductor; the second port of the first switch is connected to the first output end of the DC charging module, and a control end of the first switch is connected to the control module;

[0028] The control module is further configured to send a fourth control signal to the first switch and the first upper bridge arm unit when the battery management system sends a request to stop charging or detects that the charging power supply is disconnected;

[0029] The first switch is further configured to close in response to the fourth control signal;

[0030] The first upper bridge arm unit is further configured to be turned on in response to the fourth control signal;

[0031] The first capacitor is further used to energize the first armature inductor and the second armature inductor by utilizing the internal residual voltage;

[0032] The first armature inductance and the second armature inductance are further used to generate ripple current when powered on until the residual voltage of the first capacitor returns to zero.

[0033] In the embodiment of the present application, the residual voltage in the first capacitor is used to energize the first armature inductor and the second armature inductor to generate a ripple current until the residual voltage is consumed, thereby achieving the effect of using the armature inductor to eliminate the residual current in the bus, thereby improving the safety of the charging system.

[0034] Optionally, the system further includes:

[0035] a second switch, wherein the second switch is connected in series between the positive electrode of the power battery and the first output end of the DC charging and discharging module, and a control end of the second switch is connected to the control module;

[0036] a third switch and a resistor, wherein a first port of the third switch is connected to a first port of the resistor, a second port of the resistor is connected to the first output end of the DC charging module, and a second port of the third switch is connected to a positive electrode of the power battery; and a control end of the third switch is connected to the control module;

[0037] The control module is further configured to send a fifth control signal to the third switch upon receiving the charging request;

[0038] The third switch is configured to close in response to the fifth control signal;

[0039] The control module is further configured to send a sixth control signal to the second switch and a seventh control signal to the third switch at a fourth set time interval after the fifth control signal is sent;

[0040] The second switch is configured to close in response to the sixth control signal;

[0041] The third switch is configured to be disconnected in response to the seventh control signal.

[0042] In the embodiment of the present application, by first closing the third switch connected in series with a resistor, it is ensured that the power battery will not be damaged due to a current surge or excessive charging voltage when the charging process is started. After the charging current and voltage are stable, the second switch is switched to allow the DC charging module to directly charge the power battery, thereby ensuring the safety of the charging startup process.

[0043] Optionally, the system further includes:

[0044] a fourth switch, wherein the fourth switch is connected in series between the opposite-name end of the second armature inductor and the first capacitor, and a control end of the fourth switch is connected to the control module;

[0045] The control module is further configured to send an eighth control signal to the fourth switch upon receiving the charging request;

[0046] The fourth switch is configured to close in response to the eighth control signal;

[0047] The control module is further configured to send a ninth control signal to the fourth switch when receiving the request to stop charging or detecting that the charging power source is disconnected;

[0048] The fourth switch is further configured to be disconnected in response to the ninth control signal.

[0049] In an embodiment of the present application, a fourth switch is added between the connection point between the second armature inductance and the first capacitor, and the fourth switch is controlled to be closed only during the charging process, thereby ensuring that the process of boost charging by reusing the armature inductance is smoothly executed; at the same time, the fourth switch is controlled to be disconnected after charging is completed, thereby ensuring that the boost charging function of the drive motor does not conflict with the normal driving function.

[0050] Optionally, the control module is further used to detect whether the voltage and current provided by the DC charging module meet the preset boost charging conditions;

[0051] The control module is further configured to send the first control signal to the first upper bridge arm unit when the voltage and current provided by the DC charging module meet the boost charging condition;

[0052] The control module is further configured to send a standard charging signal to the DC charging module when it is detected that the voltage and current provided by the DC power supply module do not meet the boost charging condition;

[0053] The DC charging module is further configured to execute a preset standard charging process in response to the standard charging signal.

[0054] In the embodiment of the present application, by detecting whether the voltage and current provided by the charging pile meet the conditions for boost charging of the electric vehicle, it automatically switches to the standard charging process if it does not meet the conditions, and directly executes boost charging if it meets the conditions, so that the charging system of the electric vehicle can adapt to more charging scenarios and improve versatility.

[0055] Optionally, the system further includes a second capacitor and a third capacitor, wherein the first port of the second capacitor is connected to the first output end of the DC charging module, the second port of the second capacitor is connected to the first port of the third capacitor, the second port of the third capacitor is connected to the second output end of the DC charging module, and the connection between the second port of the second capacitor and the first port of the third capacitor is grounded;

[0056] The second capacitor and the third capacitor are used to suppress common-mode noise and common-mode interference generated in the charging system.

[0057] In the embodiment of the present application, by adding a second capacitor and a third capacitor and grounding the connection between the second capacitor and the third capacitor, the second capacitor and the third capacitor form a common-mode capacitor with a filtering effect, thereby suppressing common-mode noise and common-mode interference in the charging system.

[0058] In a second aspect, an embodiment of the present application further provides a charging method for an electric vehicle, which is applied to the charging system for the electric vehicle described in the first aspect, and the method includes:

[0059] When receiving a charging request from the battery management system, the control module sends a first control signal to the DC charging module and the first input terminal of the inverter module;

[0060] The DC charging module charges the power battery in response to the first control signal;

[0061] The inverter module switches to a first conduction mode in response to the first control signal, wherein the first conduction mode is used to indicate that the first DC terminal and the AC terminal of the inverter module are connected;

[0062] The drive motor uses the internal armature winding to store energy when powered;

[0063] After sending the first control signal, the control module sends a second control signal to the first input terminal and the second input terminal of the inverter module at an interval of a first set time;

[0064] The inverter module switches to a second conduction mode in response to the second control signal, wherein the second conduction mode is used to indicate that the first DC terminal, the second DC terminal and the AC terminal of the inverter module are conducted;

[0065] The drive motor uses the magnetic field energy stored in the armature winding to boost and charge the power battery.

[0066] In a third aspect, an embodiment of the present application further provides an electric vehicle, which includes the charging system for the electric vehicle described in the first aspect.

[0067] It should be understood that the second and third aspects of the embodiments of the present application are consistent with the technical solutions of the first aspect of the embodiments of the present application, and the beneficial effects achieved by each aspect and the corresponding feasible implementation methods are similar and will not be repeated here.

Brief Description of the Drawings

[0068] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0069] Figure 1 A schematic diagram of the structure of a charging system for an electric vehicle provided in an embodiment of the present application;

[0070] Figure 2 (a)-2(b) are schematic diagrams of current flow of a charging system provided in an embodiment of the present application;

[0071] Figure 3 A schematic diagram of the connection relationship between an inverter module and a drive motor in a charging system provided in an embodiment of the present application;

[0072] Figure 4 , Figure 5 A schematic diagram of current flow in another charging system provided in an embodiment of the present application;

[0073] Figure 6 A schematic diagram of the connection relationship of a charging system for performing a discharge process provided in an embodiment of the present application;

[0074] Figure 7 A schematic diagram of the structure of a start switch in a charging system provided in an embodiment of the present application;

[0075] Figure 8 A schematic diagram of the connection relationship of a boost charging process control switch in a charging system provided by an embodiment of the present application;

[0076] Fig. 9 (a)-9(b) are schematic diagrams of the operating status of a control module provided in an embodiment of the present application;

[0077] Fig.10 A schematic diagram of the structure of a device for suppressing common-mode noise and common-mode interference in a charging system provided in an embodiment of the present application;

[0078] Fig.11 A schematic diagram of a flow chart of a charging method for an electric vehicle provided in an embodiment of the present application;

[0079] Fig.12A schematic diagram of the structure of an electric vehicle provided in an embodiment of the present application. [Specific implementation method]

[0080] In order to better understand the technical solution of this specification, the embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0081] It should be clear that the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this specification.

[0082] The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit this specification. The singular forms of "a", "said" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

[0083] With the popularity of electric vehicle fast charging technology, a car charging system that uses high-voltage DC charging technology to achieve fast charging has been widely used in various vehicles. This charging system adds additional inductance and alternately performs boosting energy storage and discharge freewheeling with the help of the inductance to meet the demand for high-voltage fast charging of power batteries.

[0084] The inventors of the present application have found that since this type of automobile charging system requires additional inductance components to be installed for boosting and storing energy in order to achieve a normal boost charging effect, the overall production cost and maintenance cost of the charging system increase.

[0085] In view of this, an embodiment of the present application provides a charging system for an electric vehicle, which uses the armature winding inside the vehicle engine instead of the additionally installed inductive element to boost energy storage, thereby reducing the number of components required for the vehicle charging system and lowering production and maintenance costs.

[0086] The technical solution provided by the embodiments of the present application is introduced below in conjunction with the accompanying drawings.

[0087] See also Figure 1 , is a schematic diagram of a charging system for an electric vehicle provided in an embodiment of the present application. The system includes:

[0088] The control module 101, the power battery 102, the drive motor 103, the inverter module 104 and the DC charging module 105; the control module 101 is respectively connected to the first input terminal and the second input terminal of the inverter module 104, the input terminal of the DC charging module 105 and the signal output terminal of the battery management system; the first output terminal of the DC charging module 105 is connected to the positive electrode of the power battery 102, and the second output terminal of the DC charging module 105 is connected to the negative electrode of the power battery 102; the first DC terminal of the inverter module 104 is connected to the first output terminal of the DC charging module 105, the second DC terminal of the inverter module 104 is connected to the second output terminal of the DC charging module 105, the AC terminal of the inverter module 104 is connected to the first port of the drive motor 103, and the second port of the drive motor 103 is connected to the second output terminal of the DC charging module 105;

[0089] The control module 101 is configured to send a first control signal to the DC charging module 105 and the first input terminal of the inverter module 104 upon receiving a charging request from the battery management system;

[0090] A DC charging module 105, configured to charge the power battery 102 in response to a first control signal;

[0091] The inverter module 104 is used to switch to a first conduction mode in response to a first control signal, and the first conduction mode is used to indicate that the first DC terminal and the AC terminal of the inverter module 104 are connected;

[0092] A drive motor 103 for storing energy using an internal armature winding when powered on;

[0093] The control module 101 is further configured to send a second control signal to the first input terminal and the second input terminal of the inverter module 104 at a first set time interval after sending the first control signal;

[0094] The inverter module 104 is further configured to switch to a second conduction mode in response to a second control signal, wherein the second conduction mode is configured to indicate that the first DC terminal, the second DC terminal, and the AC terminal of the inverter module 104 are in conduction;

[0095] The drive motor 103 is also used to boost and charge the power battery 102 using the magnetic field energy stored in the armature winding.

[0096] In the embodiment of the present application, the principle adopted by the boost charging is the same as the general boost charging principle, that is, through the freewheeling effect of multiple inductors in the charging system and the discharge effect of the first capacitor, the equivalent voltage in the charging system is increased to the desired value, thereby realizing the rapid charging of the electric vehicle. Since the embodiment of the present application mainly involves the improvement of the inductor part, the discharge effect of the first capacitor will not be discussed below, and its principle is consistent with the general boost charging principle.

[0097] First, the control module 101 in the charging system can be any actuator, controller or system function module with control function including an electronic control unit. The DC charging module 105 can be any hardware module with charging function in the electric vehicle, which generally includes DC-DC converters, DC relays and other necessary components for realizing the charging function.

[0098] Secondly, the inverter module 104 may be any conventional DC-AC conversion circuit including but not limited to a three-phase inverter circuit, a four-phase inverter circuit, a five-phase inverter circuit, and a dual three-phase inverter circuit.

[0099] Finally, the types of the drive motor 103 include, but are not limited to, a DC motor using an armature winding, a brushless DC motor, and any other motor type having an inductance effect in the rotor that can replace the inductance for boost charging.

[0100] Figure 2 (a)- Figure 2 (b) is a schematic diagram of current flow of a charging system provided in an embodiment of the present application. Specifically, the boost charging function in the embodiment of the present application is implemented as follows:

[0101] First, if Figure 2 As shown in (a), the control module 101 receives a charging request from the battery management system, and sends a first control signal to the inverter module 104 and the DC charging module 105 according to the charging request; the DC charging module 105 closes the DC relay to energize the bus of the entire charging system. At the same time, after receiving the first control signal, the first input end of the inverter module 104 changes its internal conduction state accordingly, so that the bus current can start from the first output end of the DC charging module 105, flow to the positive electrode of the power battery, and shunt to the first DC end of the inverter module 104, and then flow out from the AC end of the inverter module 104 to reach the first port of the drive motor 103. After completing the energy storage function in the drive motor 103, it flows out from the second port and merges with the current flowing out of the negative electrode of the power battery 102, and flows back to the second output end of the DC charging module 105. Since the armature winding of the drive motor 103 has the characteristics of a winding structure and has certain inductance characteristics, it can play an energy storage effect similar to that of a general inductor during the boost charging process, preparing for subsequent boost charging.

[0102] Then, if Figure 2As shown in (b), the control module 101 sends the second control signal again after waiting for the first set time, and the inverter module 104 switches to the second conduction mode after receiving the second control signal at the first input terminal and the second input terminal. In this conduction mode, the current also flows out from the first output terminal of the DC charging module 105 and flows into the positive electrode of the power battery 102, and flows from the negative electrode of the power battery 102 into the second DC terminal of the inverter module 103; then, the current flows out from the AC terminal of the inverter module 104 to the first port of the drive motor 103, and flows out from the second port of the drive motor 103 and returns to the second output terminal of the DC charging module 105. Through this operation mode, the current flows out from the negative electrode of the power battery 102 and then flows into the drive motor 103, and then forms a series circuit between the drive motor 103 and the power battery 102, and the magnetic field energy stored in the armature winding inside the drive motor 103 is used to replace the external inductance to perform the freewheeling function, so as to realize the boost charging of the power battery 102.

[0103] The following analyzes the specific component actions in the charging system when the first control signal and the second control signal are sent, and introduces the local boost charging control process:

[0104] Figure 3 A schematic diagram of the connection relationship between an inverter module and a drive motor in a charging system provided in an embodiment of the present application. As a possible implementation, the inverter module 104 at least includes a first upper bridge arm unit 201 and a first lower bridge arm unit 202, wherein the first port of the first upper bridge arm unit 201 is connected to the first output end of the DC charging module 105, the second port of the first upper bridge arm unit 201 is connected to the first port of the first lower bridge arm unit 202, and the second port of the first lower bridge arm unit 202 is connected to the second output end of the DC charging module 105; the first upper bridge arm unit 201 and the first lower bridge arm unit 202 are both kept in a normally off state;

[0105] The armature winding of the drive motor 103 at least includes a first armature inductor 301 and a second armature inductor 302, the same-name end of the first armature inductor 301 is connected to the same-name end of the second armature inductor 302, the opposite-name end of the first armature inductor 301 is connected to the second port of the first upper bridge arm unit 201, and the opposite-name end of the second armature inductor 302 is connected to the second output end of the DC charging module 105;

[0106] The control module 101 is at least connected to the control end of the first upper bridge arm unit 201;

[0107] A first upper bridge arm unit 201, configured to be turned on in response to a first control signal;

[0108] The first armature inductor 301 and the second armature inductor 302 are used to store energy when powered on.

[0109] In the embodiment of the present application, the first port of the first upper bridge arm unit 201 is connected to the first output end of the DC charging module 105, constituting the first DC end of the inverter module 104; the second port of the first lower bridge arm unit 202 is connected to the second output end of the DC charging module 105, constituting the second DC end of the inverter module 104; the second port of the first upper bridge arm unit 201 (based on its connection relationship, that is, the first port of the first lower bridge arm unit 202) is connected to the opposite end of the first armature inductor 301 of the drive motor 103, constituting the AC end of the inverter module 104. The control end of the first upper bridge arm unit 201 is directly connected to the control module 101, constituting the first control end of the inverter module 104.

[0110] At the same time, the first armature inductor 301 of the drive motor 103 is connected to the second port of the first upper bridge arm unit 201, forming the first port of the drive motor 103, and the second armature inductor 302 is connected to the second port of the DC charging module 105, forming the second port of the drive motor 103.

[0111] Specifically, the specific working method of the inverter module 104 switching to the first conduction mode is as follows:

[0112] like Figure 3 As shown, when the control module 101 sends the first control signal to the first control terminal of the inverter module 104, the first upper bridge arm unit 201 receives the first control signal and performs conduction, that is, a forward voltage is applied between the gate and the emitter of the switch tube in the first upper bridge arm unit 201, so that the PN junction between the gate and the emitter is forward biased, thereby achieving conduction. After the conduction, the current flows from the first output terminal of the DC charging module 105 into the first port of the first upper bridge arm unit 201, and then flows from the second port of the first upper bridge arm unit 201 into the first armature inductor 301 and the second armature inductor 302 in sequence, and then returns to the second output terminal of the DC charging module 105, thereby achieving the effect of storing magnetic field energy by the first armature inductor 301 and the second armature inductor 302 while taking into account the charging of the power battery 102, so as to prepare for the subsequent boost charging.

[0113] It should be understood that in the embodiment of the present application, the first upper bridge arm unit 201 and the first lower bridge arm unit 202 are essentially switching tubes, and can be any switching tube that can be applied to the inverter module 104, including but not limited to: insulated gate bipolar transistors (IGBT tubes), damped insulated gate field effect transistors (MOSFET tubes), bipolar transistors (BJT tubes), thyristor tubes; but preferably a damped IGBT tube, because it has the advantages of fast switching speed and low driving power of the MOSFET tube, and the advantage of large saturation voltage drop of the bipolar transistor, thereby better meeting the functional requirements of the inverter module 104 in boost charging.

[0114] It should also be understood that the specific structures of the components described in the embodiments of the present application are the simplest structures rather than the only structures for realizing the functions described in this section, and it is permitted to add any device or component to the simplest structure as long as the addition of the device or component does not change the operating principle of the module.

[0115] After the first armature inductor 301 has completed energy storage, the first armature inductor 301 needs to be used to boost and charge the power battery 102 .

[0116] Figure 4 , Figure 5 is a current flow diagram of another charging system provided in an embodiment of the present application. As a possible implementation, the control module 101 is at least further connected to the control end of the first lower bridge arm unit 202;

[0117] The first upper bridge arm unit 201 is further configured to be shut down in response to a second control signal;

[0118] A first lower bridge arm unit 202, configured to be turned on in response to a second control signal;

[0119] The first armature inductor 301 and the second armature inductor 302 are also used to boost and charge the power battery 102 by utilizing the magnetic field energy stored inside when power is stopped;

[0120] The first upper bridge arm unit 201 is further configured to be turned on in response to a third control signal;

[0121] The first lower bridge arm unit 202 is further configured to be turned off in response to a third control signal;

[0122] The first armature inductor 301 and the second armature inductor 302 are also used to store energy when powered on.

[0123] In the embodiment of the present application, the control module 101 is also connected to the control end of the first lower bridge arm unit 202, forming the second control end of the inverter module 104. After sending the first control signal, the control module 101 will send a second control signal to the first control end and the second control end at the first set time interval, so that the first upper bridge arm unit 201 and the first lower bridge arm unit 202 in the inverter module 104 are switched to the second conduction mode.

[0124] Specifically, the specific working method of the inverter module 104 switching to the second conduction mode is as follows:

[0125] like Figure 4 As shown, after the first upper bridge arm unit 201 receives the second control signal, it switches from on to off, that is, the gate voltage is reduced, so that the PN junction between the gate and the emitter is reverse biased to form a high-resistance state, thereby turning off the IGBT tube, and at the same time, the first lower bridge arm unit 202 is turned on. After changing to this conduction mode, the current first flows out from the first output end of the DC charging module 105 and flows into the positive electrode of the power battery 102. Subsequently, the current flowing out from the negative electrode of the power battery 102 flows into the second port of the first lower bridge arm unit 202, and flows from the first port into the first armature inductor 301 and the second armature inductor 302, and flows back from the second armature inductor 302 to the second output end of the DC charging module 105.

[0126] In this way, the current flows out from the negative electrode of the power battery 102 and then flows into the opposite end of the first armature inductor 301, so that the first armature inductor 301, the second armature inductor 302 and the power battery 102 form a series circuit, and then the first armature inductor 301, the second armature inductor 302 play a freewheeling role, and the magnetic field energy stored inside is released to the bus in the form of current, thereby cooperating with the DC charging module 105 to complete the boost freewheeling charging of the power battery 102.

[0127] After the magnetic field energy stored in the first armature inductor 301 is released in the form of current, it is necessary to switch the conduction mode to enable the first armature inductor 301 and the second armature inductor 302 to store energy again.

[0128] like Figure 5 In order to make the process of boost freewheeling charging form a cycle, the on and off actions of the inverter module 104 upon receiving the third control signal are as follows:

[0129] The first upper bridge arm unit 201 is turned on and the first lower bridge arm unit 202 is turned off, so that the current flows from the first output end of the DC charging module 105 to the positive electrode of the power battery 102 and the first port of the first upper bridge arm unit 201 at the same time. Then, the current flowing into the first upper bridge arm unit 201 flows from the second port into the first armature inductor 301 and the second armature inductor 302, and finally merges with the current flowing out of the negative electrode of the power battery 102, and flows back into the second output end of the DC charging module 105.

[0130] In this way, the current flow between the opposite end of the first armature inductor 301 where the magnetic field energy has been released and the negative electrode of the power battery 102 is cut off, so that the first armature inductor 301 and the power battery 102 do not form a series circuit, and the first armature inductor 301 can store energy again under the power supply of the DC charging module 105. At the same time, the DC charging module 105 maintains normal charging of the power battery 102, thereby realizing a complete and sustainable energy storage and boost charging process.

[0131] When the boost charging of the power battery 102 is completed or the charging power source is disconnected, due to the existing boost charging technology, a first capacitor needs to be set in the charging system to store voltage and stabilize the voltage. After the charging is completed, if the voltage stored in the first capacitor is not effectively released, it is easy to cause safety hazards such as arcing and temperature rise. Therefore, it is also necessary to discharge the charge in the first capacitor.

[0132] Figure 6 1 is a schematic diagram of the connection relationship of a charging system for performing a discharge process provided in an embodiment of the present application. As a possible implementation, the system further includes: a first switch 203 and a first capacitor 204, a first port of the first switch 203 is connected to a first port of the first capacitor 204, a second port of the first capacitor 204 is connected to an opposite-name end of the second armature inductor 302; a second port of the first switch 203 is connected to a first output end of a DC charging module 105, and a control end of the first switch 203 is connected to a control module 101;

[0133] The control module 101 is further configured to send a fourth control signal to the first switch 203 and the first upper bridge arm unit 201 when the battery management system sends a request to stop charging or detects that the charging power supply is disconnected;

[0134] The first switch 203 is further configured to close in response to a fourth control signal;

[0135] The first upper bridge arm unit 201 is further configured to be turned on in response to a fourth control signal;

[0136] The first capacitor 204 is also used to energize the first armature inductor 301 and the second armature inductor 302 using the internal residual voltage;

[0137] The first armature inductor 301 and the second armature inductor 302 are also used to generate ripple current when powered on until the residual voltage of the first capacitor 204 returns to zero.

[0138] In the embodiment of the present application, the first capacitor 204 and the first switch 203 are generally present in the original high-voltage distribution box module of the charging system, and are used to stabilize the charging voltage provided by the DC charging module 105 to prevent it from fluctuating greatly. Since the first capacitor 204 is often charged and discharged during the process of boost charging of the electric vehicle, and there is a lack of reliable means to release the charge accumulated in the first capacitor at the end of charging, it is easy to generate high-voltage residual electricity; and the high-voltage residual electricity in the first capacitor 204 can be gradually eliminated by energizing the first armature inductor 301 and the second armature inductor 302 to generate ripple current, thereby ensuring the overall safety of the charging system.

[0139] The specific process of eliminating residual power in the charging system is as follows:

[0140] like Figure 6 As shown, first, when the control module 101 receives a request to stop charging from the battery management system, or detects that the charging power supply is disconnected in any way, it sends a fourth control signal, the first upper bridge arm unit 201 is turned on, and the first switch 203 is closed, so that the first capacitor 204 is connected to the first armature inductor 301 and the second armature inductor 302. In this connection mode, the residual electricity in the first capacitor 204 will flow into the first port of the first upper bridge arm unit 201 in the form of current, and flow through the first armature inductor 301 and the second armature inductor 302 in sequence. Then the current flows out of the second armature inductor 302 and flows back to the first capacitor 204 to form a complete loop.

[0141] Through this power-on method, the first capacitor 204 can use the internal residual voltage to energize the first armature inductor 301 and the second armature inductor 302, generate ripple current in the first armature inductor 301 and the second armature inductor 302, and gradually consume the residual voltage until the voltage carried by the first capacitor 204 returns to zero, and the safety hazard of the charging system is completely eliminated.

[0142] After the residual voltage returns to zero, the first switch 203 can be disconnected again to turn off the first upper bridge arm unit 201 that has been turned on, so that the charging system can resume the standby state after the residual power is eliminated.

[0143] In some embodiments, taking the vehicle-mounted three-phase AC motor as an example, by appropriately changing the conduction mode of the inverter module 104, the first armature inductor 301 and the second armature inductor 302 generate ripple current to eliminate residual electricity, or the first armature inductor 301 and the third armature inductor generate ripple current, or the second armature inductor 302 and the third armature inductor generate ripple current, which are all one of the embodiments of the present application. In fact, without changing the principle of the scheme, by appropriately adjusting the circuit to make any armature inductor used to generate ripple current is an extension allowed by the embodiments of the present application.

[0144] In addition, when charging starts, the safety of the components of the charging system also needs to be considered, for example, appropriate measures are provided to prevent the power battery 102 from being damaged due to a sudden surge in voltage.

[0145] Figure 7 : is a schematic diagram of a structure of a start switch in a charging system provided in an embodiment of the present application. As a possible implementation, the system further includes:

[0146] A second switch 205, which is connected in series between the positive electrode of the power battery 102 and the first output terminal of the DC charging and discharging module, and a control terminal of the second switch 205 is connected to the control module 101;

[0147] A third switch 206 and a resistor 207, wherein a first port of the third switch 206 is connected to a first port of the resistor 207, a second port of the resistor 207 is connected to a first output terminal of the DC charging module 105, and a second port of the third switch 206 is connected to a positive electrode of the power battery 102; and a control terminal of the third switch 206 is connected to the control module 101;

[0148] The control module 101 is further configured to send a fifth control signal to the third switch 206 when receiving a charging request;

[0149] A third switch 206, configured to close in response to a fifth control signal;

[0150] The control module 101 is further configured to send a sixth control signal to the second switch 205 and a seventh control signal to the third switch 206 at a fourth set time interval after the fifth control signal is sent;

[0151] The second switch 205 is configured to close in response to a sixth control signal;

[0152] The third switch 206 is configured to be disconnected in response to the seventh control signal.

[0153] In the embodiment of the present application, in order to prevent the power battery 102 from being damaged due to voltage mutation and to reasonably control the timing of connecting the charging power supply, a second switch 205 and a third switch 206 connected in parallel are added to the positive electrode of the power battery 102, and the third switch 206 is additionally connected in series with a resistor 207. The following is the charging start-up process when the second switch 205 and the third switch 206 are present:

[0154] The control module 101 sends a fifth control signal to the third switch 206, and the third switch 206 that receives the fifth control signal is closed, so that the current flows to the power battery 102 through the resistor 207 and the third switch 206, thereby limiting the magnitude of the line current by using the resistor 207. Subsequently, the control module 101 sends a sixth control signal to the second switch 205 and a seventh control signal to the third switch 206, and the second switch 205 that receives the sixth control signal is closed, and the third switch 206 that receives the seventh control signal is opened, so that the current flows to the power battery 102 through the second switch 205 instead, completing the safe start of charging.

[0155] In addition, in order to avoid the conflict between the process of reusing the armature inductance for boost charging and the normal use of the drive motor 103, the circuit needs to be further improved so that the armature winding of the drive motor 103 is connected in series with the boost charging circuit only when boost charging is required.

[0156] Figure 8 1 is a schematic diagram of the connection relationship of a boost charging process control switch in a charging system provided by an embodiment of the present application. As a possible implementation, the system also includes:

[0157] A fourth switch 208, the fourth switch 208 is connected in series between the opposite-terminal end of the second armature inductor 302 and the first capacitor 204, and a control end of the fourth switch 208 is connected to the control module 101;

[0158] The control module 101 is further configured to send an eighth control signal to the fourth switch 208 when receiving a charging request;

[0159] The fourth switch 208 is configured to close in response to an eighth control signal;

[0160] The control module 101 is further configured to send a ninth control signal to the fourth switch 208 when a request to stop charging is received or when a charging power supply is detected to be disconnected;

[0161] The fourth switch 208 is further configured to be disconnected in response to a ninth control signal.

[0162] In the embodiment of the present application, if the opposite-terminal end of the second armature inductor 302 remains connected to the second output end of the DC charging module 105, the existence of this connection may hinder the normal operation of the drive motor 103 during normal driving. Therefore, it is necessary to add a fourth switch 208 to the connection between the opposite-terminal end of the second armature inductor 302 and the second output end of the DC charging module 105, and control the fourth switch 208 to be turned on during boost charging, and to be disconnected synchronously when charging is completed or the charging power supply is disconnected, so as to ensure that the armature winding can be reused for boost charging without hindering the normal driving of the electric vehicle.

[0163] In addition, due to the limitations of hardware facilities such as charging piles, boost charging of electric vehicles may not be supported in some cases, so corresponding control measures can be taken to solve this adaptability problem.

[0164] Fig. 9 (a)-9(b) are schematic diagrams of the operating status of a control module 101 provided in an embodiment of the present application. As a possible implementation, the control module 101 is also used to detect whether the voltage and current provided by the DC charging module 105 meet the preset boost charging conditions;

[0165] The control module 101 is further configured to send a first control signal to the first upper bridge arm unit 201 when the voltage and current provided by the DC charging module 105 meet the boost charging condition;

[0166] The control module 101 is further configured to send a standard charging signal to the DC charging module 105 when it is detected that the voltage and current provided by the DC power supply module do not meet the boost charging conditions;

[0167] The DC charging module 105 is further configured to execute a preset standard charging process in response to a standard charging signal.

[0168] In actual application, due to the mismatch between the charging pile and the charging system model of the electric vehicle, the hardware limitation of the charging pile, etc., the voltage and current output by the charging pile may not meet the standard for boost charging. At this time, the control module 101 needs to detect the power supply voltage and current provided by the charging pile, and determine whether to enable the boost charging process based on whether the detection result meets the boost charging condition. The boost charging condition here can be set manually based on experience or actual measurement results, and can be adjusted arbitrarily according to different charging system models.

[0169] If both the voltage and the current meet the boost charging condition, a first control signal ① is sent to the first control terminal of the inverter module 104, that is, the control terminal of the first upper bridge arm unit 201, such as Fig. 9 (a) The normal boost charging process begins.

[0170] If the voltage or current cannot reach the standard, a standard charging signal ② is sent to the control end of the DC charging module 105, such as Fig. 9 (b) enables the latter to start a preset standard charging process. Since this standard charging process has been widely used in various electric vehicles, it will not be described here.

[0171] In addition, when the car charging system is performing charging or discharging, common mode noise and common mode interference may be generated due to the inverter module 104 providing AC power to the drive motor 103. Therefore, corresponding components need to be added to suppress these phenomena.

[0172] Fig.10 A schematic diagram of a common mode noise and common mode interference suppression device in a charging system provided in an embodiment of the present application. As a possible implementation, the system further includes a second capacitor 209 and a third capacitor 210, wherein the first port of the second capacitor 209 is connected to the first output terminal of the DC charging module 105, the second port of the second capacitor 209 is connected to the first port of the third capacitor 210, the second port of the third capacitor 210 is connected to the second output terminal of the DC charging module 105, and the connection between the second port of the second capacitor 209 and the first port of the third capacitor 210 is grounded.

[0173] The second capacitor 209 and the third capacitor 210 are used to suppress common-mode noise and common-mode interference generated in the charging system.

[0174] In the embodiment of the present application, when there is a device powered by AC power (such as the drive motor 103) in the charging system, it may cause electromagnetic disturbance in the circuit, and then common mode noise may occur. At the same time, due to the frequent signal interaction between the inverter module 104 and the control module 101, and the current switching between the components in the charging system, common mode interference may also occur.

[0175] In view of this situation, a pair of common-mode capacitors may be added to the charging system: a second capacitor 209 and a third capacitor 210 , so as to utilize the filtering effect formed by the common-mode capacitors to suppress common-mode noise and common-mode interference.

[0176] See also Fig.11 Based on the same inventive concept, the present application also provides a method for charging an electric vehicle, which is applied to Figure 1-Figure 10 The charging system for an electric vehicle according to any one of the above, wherein the steps of the method are as follows:

[0177] Step 401: upon receiving a charging request from a battery management system, the control module 101 sends a first control signal to the DC charging module 105 and the first input terminal of the inverter module 104;

[0178] Step 402: the DC charging module 105 charges the power battery 102 in response to the first control signal;

[0179] Step 403: the inverter module 104 switches to a first conduction mode in response to the first control signal, where the first conduction mode is used to indicate that the first DC terminal and the AC terminal of the inverter module 104 are conducting;

[0180] Step 404: the drive motor 103 uses the internal armature winding to store energy when powered on;

[0181] Step 405: after sending the first control signal, the control module 101 sends a second control signal to the first input terminal and the second input terminal of the inverter module 104 at a first set time interval;

[0182] Step 406: the inverter module 104 switches to a second conduction mode in response to the second control signal, where the second conduction mode is used to indicate that the first DC terminal, the second DC terminal, and the AC terminal of the inverter module 104 are conductive;

[0183] Step 407: The driving motor 103 uses the magnetic field energy stored in the armature winding to boost and charge the power battery 102 .

[0184] See also Fig.12 Based on the same inventive concept, the present application embodiment further provides an electric vehicle 500, which may include the electric vehicle 500 of the present application embodiment. Figure 1-Figure 10 The charging system shown.

[0185] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of this specification should be included in the scope of protection of this specification.

Claims

1. A charging system for an electric vehicle, characterized in that: The system comprises: a control module, a power battery, a drive motor, an inverter module and a DC charging module; the control module is respectively connected to a first input terminal and a second input terminal of the inverter module, an input terminal of the DC charging module and a signal output terminal of a battery management system; a first output terminal of the DC charging module is connected to a positive electrode of the power battery, and a second output terminal of the DC charging module is connected to a negative electrode of the power battery; a first DC terminal of the inverter module is connected to a first output terminal of the DC charging module, a second DC terminal of the inverter module is connected to a second output terminal of the DC charging module, an AC terminal of the inverter module is connected to a first port of the drive motor, and a second port of the drive motor is connected to a second output terminal of the DC charging module; The control module is configured to send a first control signal to the DC charging module and the first input terminal of the inverter module when receiving a charging request from the battery management system; The DC charging module is used to charge the power battery in response to the first control signal; The inverter module is used to switch to a first conduction mode in response to the first control signal, and the first conduction mode is used to indicate that the first DC terminal and the AC terminal of the inverter module are connected; The drive motor is used to store energy using the internal armature winding when powered on; The control module is further configured to send a second control signal to the first input terminal and the second input terminal of the inverter module at a first set time interval after sending the first control signal; The inverter module is further configured to switch to a second conduction mode in response to the second control signal, wherein the second conduction mode is configured to indicate that the first DC terminal, the second DC terminal, and the AC terminal of the inverter module are connected; The drive motor is also used to boost and charge the power battery using the magnetic field energy stored in the armature winding.

2. The system according to claim 1, characterized in that The inverter module at least includes a first upper bridge arm unit and a first lower bridge arm unit, wherein the first port of the first upper bridge arm unit is connected to the first output end of the DC charging module, the second port of the first upper bridge arm unit is connected to the first port of the first lower bridge arm unit, and the second port of the first lower bridge arm unit is connected to the second output end of the DC charging module; the first upper bridge arm unit and the first lower bridge arm unit are both kept in a normally off state; The armature winding of the drive motor at least includes a first armature inductor and a second armature inductor, the same-name end of the first armature inductor is connected to the same-name end of the second armature inductor, the opposite-name end of the first armature inductor is connected to the second port of the first upper bridge arm unit, and the opposite-name end of the second armature inductor is connected to the second output end of the DC charging module; The control module is at least connected to the control end of the first upper bridge arm unit; The first upper bridge arm unit is configured to be turned on in response to the first control signal; The first armature inductance and the second armature inductance are used to store energy when power is supplied.

3. The system according to claim 2, characterized in that The control module is at least further connected to the control end of the first lower bridge arm unit, and the first upper bridge arm unit is further used to shut down in response to the second control signal; The first lower bridge arm unit is configured to be turned on in response to the second control signal; The first armature inductor and the second armature inductor are also used to boost and charge the power battery by utilizing the magnetic field energy stored inside when power is stopped; The control module is further configured to send a third control signal to the first upper bridge arm unit and the first lower bridge arm unit at a second set time interval after sending the second control signal; The first upper bridge arm unit is further configured to be turned on in response to the third control signal; The first lower bridge arm unit is further configured to be shut down in response to the third control signal; The first armature inductance and the second armature inductance are also used to store energy when powered on.

4. The system according to claim 2, characterized in that: The system further includes: a first switch and a first capacitor, wherein a first port of the first switch is connected to a first port of the first capacitor, and a second port of the first capacitor is connected to the opposite end of the second armature inductor; the second port of the first switch is connected to the first output end of the DC charging module, and a control end of the first switch is connected to the control module; The control module is further configured to send a fourth control signal to the first switch and the first upper bridge arm unit when the battery management system sends a request to stop charging or detects that the charging power supply is disconnected; The first switch is further configured to close in response to the fourth control signal; The first upper bridge arm unit is further configured to be turned on in response to the fourth control signal; The first capacitor is further used to energize the first armature inductor and the second armature inductor by utilizing the internal residual voltage; The first armature inductance and the second armature inductance are further used to generate a ripple current when powered on until the residual voltage of the first capacitor returns to zero.

5. The system according to claim 4, characterized in that The system further comprises: a second switch, wherein the second switch is connected in series between the positive electrode of the power battery and the first output end of the DC charging and discharging module, and a control end of the second switch is connected to the control module; a third switch and a resistor, wherein a first port of the third switch is connected to a first port of the resistor, a second port of the resistor is connected to the first output end of the DC charging module, and a second port of the third switch is connected to a positive electrode of the power battery; and a control end of the third switch is connected to the control module; The control module is further configured to send a fifth control signal to the third switch upon receiving the charging request; The third switch is configured to close in response to the fifth control signal; The control module is further configured to send a sixth control signal to the second switch and a seventh control signal to the third switch at a fourth set time interval after the fifth control signal is sent; The second switch is configured to close in response to the sixth control signal; The third switch is configured to be disconnected in response to the seventh control signal.

6. The system according to claim 5, characterized in that The system further comprises: a fourth switch, wherein the fourth switch is connected in series between the opposite-name end of the second armature inductor and the first capacitor, and a control end of the fourth switch is connected to the control module; The control module is further configured to send an eighth control signal to the fourth switch upon receiving the charging request; The fourth switch is configured to close in response to the eighth control signal; The control module is further configured to send a ninth control signal to the fourth switch when receiving the request to stop charging or detecting that the charging power source is disconnected; The fourth switch is further configured to be disconnected in response to the ninth control signal.

7. The system according to claim 6, characterized in that The control module is further used to detect whether the voltage and current provided by the DC charging module meet the preset boost charging conditions; The control module is further configured to send the first control signal to the first upper bridge arm unit when the voltage and current provided by the DC charging module meet the boost charging condition; or, The control module is further configured to send a standard charging signal to the DC charging module when it is detected that the voltage and current provided by the DC power supply module do not meet the boost charging condition; The DC charging module is further configured to execute a preset standard charging process in response to the standard charging signal.

8. The system according to claim 7, characterized in that The system further includes a second capacitor and a third capacitor, wherein a first port of the second capacitor is connected to a first output terminal of the DC charging module, a second port of the second capacitor is connected to a first port of the third capacitor, a second port of the third capacitor is connected to a second output terminal of the DC charging module, and a connection point between the second port of the second capacitor and the first port of the third capacitor is grounded; The second capacitor and the third capacitor are used to suppress common-mode noise and common-mode interference generated in the charging system.

9. A method for charging an electric vehicle, characterized in that: The method applied to the charging system of the electric vehicle according to any one of claims 1 to 8 comprises: When receiving a charging request from the battery management system, the control module sends a first control signal to the DC charging module and the first input terminal of the inverter module; The DC charging module charges the power battery in response to the first control signal; The inverter module switches to a first conduction mode in response to the first control signal, wherein the first conduction mode is used to indicate that the first DC terminal and the AC terminal of the inverter module are connected; The drive motor uses the internal armature winding to store energy when powered; After sending the first control signal, the control module sends a second control signal to the first input terminal and the second input terminal of the inverter module at an interval of a first set time; The inverter module switches to a second conduction mode in response to the second control signal, wherein the second conduction mode is used to indicate that the first DC terminal, the second DC terminal and the AC terminal of the inverter module are conducted; The drive motor uses the magnetic field energy stored in the armature winding to boost and charge the power battery.

10. An electric vehicle, characterized in that: The electric vehicle comprises the charging system for an electric vehicle according to any one of claims 1-8.

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