CN117748927A - Charging control method, alternating current-direct current conversion module, energy storage equipment and charging system - Google Patents

Abstract

The application discloses a charging control method, an alternating current-direct current conversion module, energy storage equipment and a charging system. The charging module comprises a natural rectifying unit, a filtering unit and an isolation DC/DC unit, wherein the natural rectifying unit is connected with power supply equipment and is used for rectifying three-phase alternating voltage provided by the power supply equipment into direct voltage; the filtering unit is connected with the natural rectifying unit and is used for filtering the direct-current voltage and inhibiting a current peak value; the isolation DC/DC unit is connected with the filtering unit and is used for carrying out voltage conversion on the filtered direct-current voltage. The charge control method includes: acquiring input current of a charging module; determining a compensation current based on the input current; and adjusting the output current of the power supply device based on the compensation current, wherein the power supply device is connected with the input side of the charging module. The charging system provided by the application has the advantages of low cost, simple structure and high efficiency on the basis of meeting the requirements of power factor controllability, peak clipping and valley filling at the power grid side.

Description

Charging control method, alternating current-direct current conversion module, energy storage equipment and charging system

Technical Field

The application relates to the technical field of electric automobile charging, in particular to a charging control method, an alternating current-direct current conversion module, energy storage equipment and a charging system.

Background

The output of the power grid transformer is generally AC 380V, the charging pile adopts a multi-module parallel connection to output larger power, the charging module is generally used for two-stage topology, the front-stage PFC (Power Factor Correction ) is rectified, the rear-stage isolation DC/DC is carried out, and the active PFC topology works by adopting a power electronic topology switch, so that the overall efficiency is lower and the structure is complex.

The foregoing is merely provided to facilitate an understanding of the principles of the present application and is not admitted to be prior art.

Disclosure of Invention

The main purpose of the application is to provide a charging control method, an alternating current-direct current conversion module, energy storage equipment and a charging system, and aims to solve the problems of complex structure and high cost of the existing charging system.

In order to achieve the above object, the present application provides a charging control method, including: acquiring input current of a charging module; determining a compensation current based on the input current; and adjusting the output current of a power supply device based on the compensation current, wherein the power supply device is connected with the input side of the charging module.

Optionally, the determining the compensation current based on the input current includes: acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is smaller than the capacity power, determining a target current based on the actual output power and the phase voltage parameter; a compensation current is determined based on the target current and the input current.

Optionally, the determining the compensation current based on the input current includes: acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is smaller than the capacity power, determining a target current based on the actual output power and the phase voltage parameter; determining a charging current to an energy storage battery based on a capacity power of the power supply device, the actual output power, and a charging power of the energy storage battery; a compensation current is determined based on the input current, the target current, and the charging current.

Optionally, the phase voltage parameter includes a phase voltage and a phase of a corresponding phase; said determining a target current based on said actual output power and said phase voltage parameter comprises: determining a phase current effective value based on the actual output power and the phase voltage; the target current is determined based on the phase current effective value and the phase of the corresponding phase.

Optionally, the determining the compensation current based on the input current includes: acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is greater than the capacity power, determining a target current based on the capacity power and the phase voltage parameter; a compensation current is determined based on the target current and the input current.

Optionally, the phase voltage parameter includes a phase voltage and a phase of a corresponding phase; the determining a target current based on the capacity power and the phase voltage parameter includes: determining a phase current effective value based on the capacity power and the phase voltage; a target current is determined based on the phase current effective value and the phase of the corresponding phase.

Optionally, the determining the compensation current based on the input current includes: determining a fundamental component and a harmonic component of the input current; a compensation current is determined based on the fundamental component and the harmonic component.

In addition, in order to achieve the above purpose, the present application further provides an ac/dc conversion module, where the ac/dc conversion module includes an ac/dc conversion unit and a control unit connected with the ac/dc conversion unit, where the ac/dc conversion unit is connected to an input side of the charging module, and the control unit is configured to execute the charging control method according to any embodiment of the present application.

Optionally, the control unit is configured to: acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is smaller than the capacity power, determining a target current based on the actual output power and the phase voltage parameter; determining a compensation current based on the target current and the input current; or acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is smaller than the capacity power, determining a target current based on the actual output power and the phase voltage parameter; determining a charging current to an energy storage battery based on a capacity power of the power supply device, the actual output power, and a charging power of the energy storage battery; a compensation current is determined based on the input current, the target current, and the charging current.

Optionally, the control unit is further configured to: acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is greater than the capacity power, determining a target current based on the capacity power and the phase voltage parameter; a compensation current is determined based on the target current and the input current.

In addition, to achieve the above object, the present application further provides an energy storage device, including: the ac/dc conversion module according to any embodiment of the present application; the energy storage battery is connected with the alternating current-direct current conversion module; wherein the energy storage device is at least for: and determining a difference power based on the capacity power of the power supply equipment and the actual output power of the charging module, and performing power scheduling based on the difference power.

In addition, to achieve the above object, the present application further provides a charging system, including: the ac/dc conversion module according to any embodiment of the present application; and the charging module is connected with the power supply equipment and is used for providing direct-current charging voltage for a load connected with the power supply equipment by utilizing the alternating-current voltage output by the power supply equipment.

Optionally, the charging module includes: the natural rectification unit is connected with the power supply equipment and is used for rectifying alternating voltage provided by the power supply equipment into direct voltage; the filtering unit is connected with the natural rectifying unit and is used for filtering the direct-current voltage and inhibiting a current peak value; and the isolation DC/DC unit is connected with the filtering unit and is used for carrying out voltage conversion on the filtered direct-current voltage.

Optionally, the natural rectification unit comprises a rectification bridge, and the filtering unit comprises an inductive reactance subunit and a capacitive reactance subunit; the input end of the rectifier bridge is connected with the power supply equipment, one end of the inductive reactance subunit is connected with the first output end of the rectifier bridge, the other end of the inductive reactance subunit is connected with one end of the capacitive reactance subunit, and the other end of the capacitive reactance subunit is connected with the second output end of the rectifier bridge; or the inductive reactance subunit is connected in series between the rectifier bridge and the power supply equipment, and the capacitive reactance subunit is connected in parallel with two output ends of the rectifier bridge.

Optionally, the rectifier bridge comprises a first bridge arm, a second bridge arm and a third bridge arm which are arranged in parallel, and the first bridge arm to the third bridge arm comprise an upper half bridge and a lower half bridge; the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm are respectively and correspondingly connected with a phase voltage output end, the first output end of the first bridge arm, the first output end of the second bridge arm and the first output end of the third bridge arm are respectively connected with one end of the inductive reactance subunit, the second output end of the first bridge arm, the second output end of the second bridge arm and the second output end of the third bridge arm are respectively connected with one end of the capacitive reactance subunit, and the other end of the capacitive reactance subunit is connected with the other end of the inductive reactance subunit.

Optionally, the rectifier bridge comprises a first bridge arm, a second bridge arm and a third bridge arm which are arranged in parallel, and the first bridge arm to the third bridge arm comprise an upper half bridge and a lower half bridge; the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm are all connected with a phase voltage output end through an inductive reactance subunit, the first output end of the first bridge arm, the first output end of the second bridge arm and the first output end of the third bridge arm are respectively connected with one end of the capacitive reactance subunit, and the second output end of the first bridge arm, the second output end of the second bridge arm and the second output end of the third bridge arm are respectively connected with the other end of the capacitive reactance subunit.

Optionally, the rectifier bridge includes a rectifier diode and/or a thyristor.

In the charging system provided by the application, the charging module is composed of the natural rectifying unit, the filtering unit and the isolation DC/DC unit, compared with the traditional active PFC topology, the structure of the charging module is simplified, and the charging system has the advantage of being simple in structure. The natural rectification unit can improve the rectification efficiency, the current peak value in the output current of the charging module is restrained through the filtering unit, the AC/DC conversion module can provide compensation current according to the input current of the charging module besides power scheduling, and therefore power supply equipment can output ideal target current, and power factors of a charging system are improved. Therefore, the embodiment of the application has the advantages of low cost, simple structure and high efficiency on the basis of meeting the requirements of power factor controllability, peak clipping and valley filling at the power grid side through the matching of the charging module and the alternating current-direct current conversion module.

Drawings

Fig. 1 is a block diagram of an ac-dc conversion module according to an embodiment of the present application;

fig. 2 is a schematic structural view of a charging system according to an embodiment of the present application;

FIG. 3 is a block diagram of an energy storage device according to one embodiment of the present application;

fig. 4 is a schematic structural view of a charging system according to another embodiment of the present application;

fig. 5 is a schematic structural view of a charging system according to still another embodiment of the present application;

FIG. 6 is a topology diagram of a charging module according to one embodiment of the present application;

fig. 7 is a schematic circuit configuration diagram of a charging module according to an embodiment of the present application;

fig. 8 is a schematic circuit configuration diagram of a charging module according to another embodiment of the present application;

FIG. 9 is another exemplary schematic diagram of the natural rectifying unit of FIG. 7;

FIG. 10 is another exemplary schematic diagram of the natural rectifying unit of FIG. 8;

fig. 11 is a flowchart of a charge control method according to an embodiment of the present application.

The realization, functional characteristics and advantages of the present application will be further described with reference to the embodiments, referring to the attached drawings.

Detailed Description

The following description of the embodiments of the present invention will be made clearly and fully with reference to the accompanying drawings, in which it is evident that the embodiments described are only some, but not all embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

It should be noted that all directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are merely used to explain the relative positional relationship, movement, etc. between the components in a particular posture (as shown in the drawings), and if the particular posture is changed, the directional indicator is changed accordingly.

In the present invention, unless specifically stated and limited otherwise, the terms "connected," "affixed," and the like are to be construed broadly, and for example, "affixed" may be a fixed connection, a removable connection, or an integral body; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In addition, if there is a description of "first", "second", etc. in the embodiments of the present invention, the description of "first", "second", etc. is for descriptive purposes only and is not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In addition, the meaning of "and/or" as it appears throughout includes three parallel schemes, for example "A and/or B", including the A scheme, or the B scheme, or the scheme where A and B are satisfied simultaneously. In addition, the technical solutions of the embodiments may be combined with each other, but it is necessary to base that the technical solutions can be realized by those skilled in the art, and when the technical solutions are contradictory or cannot be realized, the combination of the technical solutions should be considered to be absent and not within the scope of protection claimed in the present invention.

Fig. 1 is a block diagram of an ac/dc conversion module according to an embodiment of the present application, as shown in fig. 1, the ac/dc conversion module 1 may include an ac/dc conversion unit 11 and a control unit 12, where the ac/dc conversion unit 11 is connected to an input side of the charging module, and the control unit 12 is connected to the ac/dc conversion unit 11. As shown in fig. 2, in the present exemplary embodiment, the ac/dc conversion module 1 may be used as a separate functional module directly applied to the charging system to adjust the power factor of the charging system.

The present application further provides an energy storage device, fig. 3 is a block diagram of an energy storage device according to an embodiment of the present application, as shown in fig. 3, the energy storage device 20 may include the ac-dc conversion module 1 shown in fig. 1, for example, the energy storage device 20 may include the energy storage converter 21, and the energy storage converter 21 may include the ac-dc conversion module 1 shown in fig. 1. In addition, as shown in fig. 3, the energy storage device 20 may further include an energy storage battery 22, where the energy storage battery 22 is connected to the ac/dc conversion module 1; wherein the energy storage device 20 is at least operable to: the power scheduling method comprises the steps of determining a differential power based on the capacity power of the power supply device and the actual output power of the charging module, and performing power scheduling based on the differential power.

In an exemplary embodiment of the present application, as shown in fig. 4, the ac/dc conversion module 1 may be integrated in the energy storage converter 21, where the energy storage converter 21 is applied to a charging system, and harmonic treatment is performed on the charging system through the energy storage converter 21. Or, as shown in fig. 5, the ac/dc conversion module 1 may be integrated in the energy storage converter 21, the energy storage converter 21 is integrated in the energy storage device 20, the energy storage device 20 may further include the energy storage battery 22, and then the energy storage device 20 is applied to the charging system, under this structure, the ac/dc conversion module 1 may not only perform harmonic treatment on the charging system to raise the power factor, but also perform power scheduling on the charging system by using the energy storage battery 22 in the energy storage system, so as to implement peak clipping and valley filling functions on electric energy.

The function of the ac/dc conversion module 1 will be further described below by taking the structure shown in fig. 5 as an example. As shown in fig. 5, the ac/dc conversion module 1 may include an energy storage converter 21, the energy storage converter 21 may be connected to each phase voltage output terminal of the power supply device 30 through a plurality of connection terminals in a one-to-one correspondence, and the control unit may be configured to obtain an input current of the charging module 10, determine a compensation current based on the input current, and adjust an output current of the power supply device 30 based on the compensation current.

Specifically, the input current of the charging module 10 may be collected in real time by a current sensor, and the current sensor transmits the collected input current of the charging module 10 to the ac/dc conversion module 1. After the ac-dc conversion module 1 in the energy storage converter 21 obtains the ac side current of the charging module 10, the ac-dc conversion module 1 can further determine and provide the compensation current, so that the output current of the power supply device 30 is adjusted, thereby eliminating the harmonic interference in the input current of the charging module 10 and improving the power factor of the charging system.

As shown in fig. 5, taking phase a electricity in the drawing as an example, the current Ia is a target current provided by the power supply device 30, ia1 is an input current of the charging module 10, ia2 is a compensation current provided by the ac-dc conversion module 1, the ac-dc conversion module 1 can output the compensation current, the difference value between the input current of the charging module 10 and the compensation current is the target current output by the power supply device 30, and the compensation current is adjusted in real time according to the input current so that the target current is an ideal sine wave current, thereby eliminating harmonic components and improving the power factor of the charging system. It should be understood that the current Ia2 in the figure may also flow to the ac-dc conversion module 1, and the current direction in the figure is only exemplary.

In an exemplary embodiment, the ac/dc conversion module 1 may also acquire actual output power and phase voltage parameters of the charging module 10, determine a target current based on the actual output power and phase voltage parameters, and determine and provide a compensation current based on the input current and the target current.

Specifically, the actual output power of the charging module 10 is the required power of the load connected to the charging module 10, and the actual output power can be adjusted according to the load. In an actual application scenario, the charging module 10 may be, for example, a charging pile, and the actual output power is the output power of the charging pile, where the actual output power may be transmitted to the ac/dc conversion module 1 through the charging pile system, or the ac/dc conversion module 1 may also obtain the actual output power through real-time detection by a sensor, or may also be uniformly scheduled to the ac/dc conversion module 1 by an additional third party monitoring system, for example, the monitoring system transmits the actual output power to the charging module 10 and simultaneously transmits the actual output power to the ac/dc conversion module 1.

The phase voltage parameters described in the present exemplary embodiment may include phase voltages and phases of the corresponding phases. The phase voltage is the effective value of the phase voltage of the single-phase power, the phase corresponds to the phase voltage, the direct current conversion module 1 can only acquire the phase of one phase of power, and then the phase of other phases is obtained through algorithm processing by utilizing the symmetry of the three-phase power. Of course, the dc conversion module 1 may directly acquire the electric phases of the respective phases.

The ac/dc conversion module 1 may sample to obtain an effective value of the phase voltage of the power supply device 30, and may detect the phase voltage waveform of the power supply device 30 to obtain the phase of the phase voltage by performing waveform scaling or may obtain the phase of the phase voltage by a phase-locked loop. The ac/dc conversion module 1 further calculates a phase current effective value corresponding to the phase current according to the phase voltage effective value and the phase of the phase voltage, so as to calculate an output current of the phase current, that is, a target current. The ac/dc conversion module 1 further determines and supplies a compensation current in combination with the sampled ac side current of the charging module 10 after obtaining the target current.

For example, taking the a-phase electricity in fig. 5 as an example, after obtaining the phase voltage of the a-phase electricity of the power supply device 30 and the actual output power of the charging module 10, the ac/dc conversion module 1 may calculate the phase current effective value of the corresponding phase of the power supply device 30 according to the following formula:

Irms＝Po/Vrms (1)

wherein: po is the actual output power of the charging module 10, vrms is the phase voltage effective value of the power supply device 30, and Irms is the phase current effective value of the corresponding phase electricity of the power supply device 30.

The ac/dc conversion module 1 further calculates a current effective value of the a-phase current, i.e., a target current, according to the following formula:

Ia＝1.414*Irms*sin(θ) (2)

Wherein: ia is a target current of the power supply apparatus 30 corresponding to the phase electricity, irms is a phase current effective value of the power supply apparatus 30 corresponding to the phase electricity, and θ is a phase of the corresponding phase electricity.

Taking the example that the capacity power of the power supply device 30 is greater than the actual output power of the charging module 10, at this time, as shown in fig. 5, the ac/dc conversion module 1 determines the compensation current according to Ia 2=ia 1-Ia, where Ia2 is the compensation current, and the ac/dc conversion module 1 outputs the compensation current, so that the input current harmonic wave of the charging module 10 meets the system requirement, and the power factor of the charging system is improved.

With continued reference to fig. 5, in an exemplary embodiment, the ac to dc conversion module 1 may also determine a differential power based on the capacity power of the power supply device 30 and the actual output power of the charging module 10, and perform power scheduling based on the differential power. That is, the ac/dc conversion module 1 can utilize the energy storage battery 22 in the energy storage device 20 to peak-cut and valley-fill the electric energy of the power supply device 30, so as to improve the utilization rate of the electric energy and meet the charging requirement, and the specific implementation process of the power scheduling can be referred to the description of the following embodiments, which is not expanded herein.

In the case of power scheduling, the ac/dc conversion module 1 needs to determine the compensation current to be provided according to the target current on the network side, the input current of the charging module, and the charging current. For example, the ac/dc conversion module 1 may obtain actual output power and phase voltage parameters of the charging module, and if the actual output power is smaller than the capacity power, the ac/dc conversion module 1 may determine the target current based on the actual output power and the phase voltage parameters, determine the charging current to the energy storage battery based on the capacity power of the power supply device, the actual output power, and the charging power of the energy storage battery, and determine the compensation current based on the input current, the target current, and the charging current. In this case, the ac/dc conversion module 1 provides the compensation current to perform harmonic suppression on one hand, so as to boost the power factor of the charging system, and charges the energy storage battery in the energy storage device by using the surplus power of the power supply device on the other hand, and a specific determination method of the compensation current in this case can be referred to the description of the subsequent embodiments, which is not developed here.

With continued reference to fig. 5, in an exemplary embodiment, the ac-dc conversion module 1 may also obtain actual output power and phase voltage parameters of the charging module; if the actual output power is larger than the capacity power, determining a target current based on the capacity power and the phase voltage parameter; a compensation current is determined based on the target current and the input current. For a specific method of determining the compensation current in this case, reference is made to the description of the subsequent method embodiments, which are not developed here.

In other embodiments of the present application, the ac-dc conversion module 1 may also be configured to obtain an input current of the charging module 10 and determine a harmonic component of the input current, and determine and provide a compensation current based on the harmonic component. In this embodiment, the ac/dc conversion module 1 may detect the input current of the charging module 10, that is, the ac side current of the charging module 10 in real time, and then the ac/dc conversion module 1 may calculate the harmonic component of the input side current of the charging module 10 by using a harmonic decomposition method (for example, fourier transform), and determine the harmonic component as a compensation current, where the ac/dc conversion module 1 further provides the compensation current to enable the power supply device 30 to output the target current, so that the input current harmonic of the charging module 10 may also meet the system requirement.

On the basis of the above embodiment, the present application also provides a charging system that can be used to charge a load by the dc voltage output by its charging module 10, for example, to charge an electric vehicle. With continued reference to fig. 5, the charging system may include the ac-dc conversion module 1 described in any of the above embodiments, and further, the charging may further include the charging module 10, where the charging module 10 and the ac-dc conversion module 1 are connected to the power supply device 30.

In the charging system provided by the application, the charging module 10 can be composed of the natural rectifying unit 100, the filtering unit 200 and the isolation DC/DC unit 300, and compared with the traditional active PFC topology, the charging module 10 has the advantages of simplifying the structure and having simple structure. The natural rectification unit 100 can improve the rectification efficiency, and the filtering unit 200 can suppress the current peak value in the output current of the charging module 10, and the ac/dc conversion module can provide compensation current according to the input current of the charging module 10 besides power scheduling, so that the power supply equipment can output ideal target current, and the power factor of the charging system is improved. Therefore, the embodiment of the application has the advantages of low cost, simple structure and high efficiency on the basis of meeting the requirements of controllable power factors and peak clipping and valley filling at the power grid side through the matching of the charging module 10 and the alternating current-direct current conversion module.

The structure of the charging module 10 in the present application is further described below with reference to the accompanying drawings. Fig. 6 is a topological structure diagram of a charging module according to an embodiment of the present application, and as shown in fig. 6, in this exemplary embodiment, the charging module 10 may include a natural rectifying unit 100, a filtering unit 200, and an isolated DC/DC unit 300, wherein the natural rectifying unit 100 is connected to a power supply device, and the natural rectifying unit 100 may be used to rectify a three-phase ac voltage provided by the power supply device into a DC voltage; the filtering unit 200 is connected with the natural rectifying unit 100, and the filtering unit 200 can be used for filtering the direct-current voltage and inhibiting the current peak value; the isolated DC/DC unit 300 is connected to the filtering unit 200, and the isolated DC/DC unit 300 may be used to perform voltage conversion on the filtered DC voltage.

In the charging module 10 provided in this embodiment of the present application, the provided natural rectification unit 100 can rectify an ac voltage into a DC voltage, the filtering unit 200 can suppress a current peak in an output current of the charging module 10, and the charging module 10 is composed of the natural rectification unit 100, the filtering unit 200 and the isolation DC/DC unit 300. The natural rectification unit 100 can improve the rectification efficiency, the current peak value in the output current of the charging module 10 is restrained through the filter unit 200, and after the current compensation is carried out by matching with the AC/DC conversion module 1, the power factor of the charging system can be improved, the defect of low power factor of the natural rectification unit 100 due to large harmonic wave is overcome, and therefore the charging system provided by the application has a higher power factor on the basis of simplifying the circuit structure and improving the efficiency, and another feasible topological structure is provided for the industrial charging system.

As shown in fig. 5 and 6, in the present exemplary embodiment, the power supply apparatus 30 outputs three-phase electricity (Ua, ub, and Uc), that is, the charging module 10 of the present application is a charging scenario applied to an industrial level. The power supply device 30 may be, for example, a power grid or a device that performs voltage conversion on a power grid voltage, and may be, for example, a transformer, a power distribution cabinet, or the like. The charging module 10 can be applied to a vehicle-mounted charging pile, and charges an electric vehicle by using three-phase electricity.

The natural rectifying unit 100 is a rectifying unit without power factor correction, and is configured to rectify an ac voltage on an ac side into a dc voltage and output the dc voltage, so that switching loss can be reduced and power utilization efficiency can be improved as compared with active PFC rectification.

The filtering unit 200 is not only used for filtering the output voltage of the natural rectifying unit 100, but also for suppressing the current peak of the output current of the natural rectifying module, where the suppressing the current peak refers to preventing the current from suddenly changing to increase the duration of the current, so that the reactive current can be reduced, and the power factor of the charging module 10 can be improved to some extent.

The isolated DC/DC unit 300 may perform voltage variation on the DC voltage after the DC filtering to adjust the output voltage of the charging module 10. For example, the voltage can be increased or decreased, and then the voltage is converted and then output to the load so as to match the loads with different voltage levels.

The charging module 10 is particularly suitable for a charging scene with small change of the required voltage of the load so as to reduce the voltage regulation requirement on the isolated DC/DC unit 300, thereby simplifying the circuit structure of the isolated DC/DC unit 300. For example, the charging module 10 of the present application may be applied to a home charging post, or may be applied to a public charging post with a charging voltage requirement of an electric vehicle close to or the same as that of the electric vehicle, for example, in some bus parks or in a family or company, where the types of electric vehicles used are the same, and the charging module 10 of the present application may be used in the public charging post.

Fig. 7 is a schematic circuit diagram of a charging module according to an embodiment of the present application, as shown in fig. 7, in an exemplary embodiment, the natural rectification unit 100 may include a rectification bridge, the filtering unit 200 may include an inductive reactance subunit 201 and a capacitive reactance subunit 202, an input end of the rectification bridge is connected to the power supply device 30, one end of the inductive reactance subunit 201 is connected to a first output end of the rectification bridge, the other end of the inductive reactance subunit 201 is connected to one end of the capacitive reactance subunit 202, and the other end of the capacitive reactance subunit 202 is connected to a second output end of the rectification bridge.

Specifically, the rectifier bridge may be a full-bridge structure including an upper half-bridge and a lower half-bridge to improve the rectifier efficiency. The power supply apparatus 30 outputs 380V of three-phase power, and accordingly the power supply apparatus 30 has three phase voltage output terminals, on the basis of which the natural rectifying unit 100 may include three rectifying bridges connected to the three phase voltage output terminals in one-to-one correspondence. The natural rectifying unit 100 has three-phase voltages on the input side and large electrolytic capacitors on the output side, and charges the bus when the three-phase voltages on the input side are greater than the bus voltage on the output side, and increases the bus voltage, and when the three-phase voltages on the input side are lower than the bus voltage on the output side, the bus voltage supplies power to the load and decreases, and the cycle repeats. One end of the inductive reactance subunit 201 is connected with a first output end of the rectifier bridge, the other end of the inductive reactance subunit 201 is connected with one end of the capacitive reactance subunit 202, and the other end of the capacitive reactance subunit 202 is connected with a second output end of the rectifier bridge, namely, the inductive reactance subunit 201 and the capacitive reactance subunit 202 form a filtering unit 200 on a direct current output side of the rectifier bridge so as to filter the rectified direct current voltage and condition the rectified output current.

In the present exemplary embodiment, the inductive reactance subunit 201 may be formed of an inductance L1, and the capacitive reactance subunit 202 may be formed of a capacitance C1, thus forming an LC filter circuit. Compared with the conventional filter unit 200 composed of the capacitive reactance subunit 202 alone, by providing the inductive reactance subunit 201 in the filter unit 200, the current abrupt change can be suppressed, so that the current peak of the charging module 10 can be suppressed, the phase difference between the output current and the output voltage of the rectifying module can be reduced, and thus the power factor of the charging module 10 can be improved.

For example, with continued reference to fig. 7, the rectifier bridge may include a first bridge arm, a second bridge arm, and a third bridge arm that are disposed in parallel, where each of the first bridge arm to the third bridge arm includes an upper half bridge and a lower half bridge, each of a midpoint of the first bridge arm, a midpoint of the second bridge arm, and a midpoint of the third bridge arm is correspondingly connected to a phase voltage output end, the first output end of the first bridge arm, the first output end of the second bridge arm, and the first output end of the third bridge arm are respectively connected to one end of the inductive reactance unit 201, the second output end of the first bridge arm, the second output end of the second bridge arm, and the second output end of the third bridge arm are respectively connected to one end of the capacitive reactance unit 202, and the other end of the capacitive reactance unit 202 is connected to the other end of the inductive reactance unit 201. The first bridge arm and the second bridge arm are connected to each other, and the second bridge arm is connected to the first half bridge and the second half bridge.

Fig. 8 is a schematic circuit diagram of a charging module according to another embodiment of the present application, as shown in fig. 8, in an exemplary embodiment, an inductive reactance subunit 201 is connected in series between a rectifier bridge and a power supply device 30, and a capacitive reactance subunit 202 is connected in parallel to two output terminals of the rectifier bridge.

Specifically, compared to the circuit structure shown in fig. 7, the inductive reactance subunit 201 is connected in series between the rectifier bridge and the power supply device 30, that is, the inductive reactance subunit 201 is disposed on the ac side of the natural rectifier unit 100, and the capacitive reactance subunit 202 is connected in parallel to two output ends of the rectifier bridge, that is, the capacitive reactance subunit 202 is disposed on the dc side of the natural rectifier unit 100. When current passes, the inductive reactance subunit 201 can suppress current abrupt change on the ac side, that is, suppress peak current on the ac side and does not affect voltage phase on the ac side, so that the power factor of the charging module 10 can be improved as well.

With continued reference to fig. 8, in an exemplary embodiment, the rectifier bridge may also include a first leg, a second leg, and a third leg that are arranged in parallel, where each of the first leg to the third leg includes an upper half-bridge and a lower half-bridge; the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm are all connected with corresponding phase voltage output ends through an inductive reactance subunit 201, the first output end of the first bridge arm, the first output end of the second bridge arm and the first output end of the third bridge arm are connected with one end of the capacitive reactance subunit 202, and the second output end of the first bridge arm, the second output end of the second bridge arm and the second output end of the third bridge arm are connected with the other end of the capacitive reactance subunit 202. As can be seen from comparing fig. 7 and 8, in the present exemplary embodiment, the inductive reactance subunit 201 performs peak suppression of current on the ac side of the natural rectifying unit 100, so that the dc current on the output side of the natural rectifying unit 100 can be improved correspondingly, which has a similar effect to the circuit structure shown in fig. 7, and the process of rectifying the three-phase power of the power supply device 30 by the rectifier bridge is similar to that of fig. 7, and will not be repeated here.

It should be understood that the midpoint of a certain bridge arm in the embodiments of the present application refers to the connection point of the upper bridge and the lower half bridge of the bridge arm.

In connection with fig. 7 and 8, in an exemplary embodiment, the rectifier bridge may be implemented by rectifier diodes, i.e., an upper half bridge and a lower half bridge of the rectifier bridge are configured by rectifier diodes, and in particular, the upper half bridge of the first bridge arm may include a first rectifier diode D1, and the lower half bridge of the first bridge arm may include a second rectifier diode D2; the upper half bridge of the second bridge arm may include a third rectifying diode D3, and the lower half bridge of the second bridge arm may include a fourth rectifying diode D4; the upper half bridge of the third leg may include a fifth rectifying diode D5 and the lower half bridge of the third leg may include a sixth rectifying diode D6. Taking the first bridge arm in fig. 7 as an example, the anode of the first rectifying diode D1 is connected to the a-phase electrical output end, the cathode is used as the first output end of the first bridge arm, the anode of the second rectifying diode D2 is used as the second output end of the first bridge arm, and the cathode is connected to the a-phase electrical output end. Likewise, the second leg and the third leg have similar structures as the first leg. In fig. 8, the anode of the first rectifying diode D1 and the cathode of the second rectifying diode D2 are connected to the phase a electric output terminal through an inductive reactance unit, and the connection manner of other bridge arms is similar to that of the first bridge arm, which is not described herein.

In other embodiments of the present application, the rectifier bridge may also be implemented by a thyristor, that is, the upper half bridge and the lower half bridge of the rectifier bridge are formed by thyristors. Fig. 9 is another exemplary structural schematic diagram of the natural rectifying unit in fig. 7, fig. 10 is another exemplary structural schematic diagram of the natural rectifying unit in fig. 8, and in combination with fig. 9 and 10, the upper half bridge of the first bridge arm may include a first thyristor SC1, and the lower half bridge may include a second thyristor SC2; the upper half bridge of the second bridge arm may include a third thyristor SC3, and the lower half bridge may include a fourth thyristor SC4; the upper half bridge of the third leg may include a fifth thyristor SC5 and the lower half bridge may include a sixth thyristor SC6.

In the first bridge arm, the first end of the first silicon controlled SC1 is connected to the a-phase electrical output end, the second end is used as the first output end of the first bridge arm, the control end may be connected to the control device in the charging system, the first end of the second silicon controlled SC2 is used as the second output end of the first bridge arm, the second end is connected to the a-phase electrical output end, the control end may be connected to the control device in the charging system, and the connection modes of the silicon controlled rectifiers in other bridge arms are similar. Therefore, the control equipment can output corresponding control signals according to the phase change time of the three-phase power to change the conduction angle of the controllable silicon, control the connection or disconnection of each controllable silicon and rectify the alternating current voltage into the direct current voltage. In addition, compared with the rectifier bridge formed by the rectifier diodes, the rectifier bridge formed by the controllable silicon can adjust the direct-current voltage of the rectification output, and is beneficial to reducing the voltage adjusting pressure of the isolation DC/DC unit 300 at the later stage.

Of course, it should be understood that in other embodiments, IGBTs may also be used to construct the rectifier bridge. The present application prefers to use diodes and/or thyristors to construct the rectifier bridge to reduce the hardware cost of the charging module 10 and simplify the circuit structure of the charging module 10.

As described above, the natural rectifying unit 100 has no power factor adjusting function, in this embodiment, the ac/dc conversion module 1 is provided in the charging system to compensate the output current of the power supply device 30, so as to eliminate the harmonic signal in the output current of the power supply device 30, reduce the phase difference between the output current and the output voltage of the power supply device 30, and thus, the power factor of the charging system can be improved, and the reactive power loss of the charging system can be reduced.

Compared with the traditional topological structure of integrating PFC power factor correction in the charging module 10, the charging system provided by the embodiment of the application utilizes the natural rectifying unit 100 with simple structure and higher efficiency to form the charging module 10, and then utilizes the AC-DC conversion module 1 to regulate the power factor of the charging system, and the function expansion of the AC-DC conversion module 1 improves the power factor and the charging efficiency of the charging system, and simultaneously simplifies the topological structure of the charging system as a whole, and reduces the hardware cost of the charging system.

The charging control method of the charging system in the present application is described in detail below.

Based on the above embodiments, fig. 11 is a flowchart of a charging control method according to an embodiment of the present application, where the method may be applied to a charging system to adjust a power factor and/or perform power scheduling of the charging system, so as to implement a peak clipping and valley filling function of electric energy. The charging control method may be performed by the ac/dc conversion module 1 in the charging system, specifically, may be performed by the control unit 12 in the ac/dc conversion module 1, or may also be performed by a separate controller in the charging system, and the present exemplary embodiment exemplifies only the case where the method is implemented by the ac/dc conversion module 1. As shown in fig. 11, the charge control method may include the steps of:

s110, acquiring input current of a charging module.

S120, determining a compensation current based on the input current.

And S130, adjusting the output current of the power supply equipment based on the compensation current.

The ac/dc conversion module 1 may collect the ac side current of the charging module 10, that is, the input current, and take fig. 5 as an example, the input current of the charging module 10 is the currents Ia1, ib1 and Ic1.

As described above, the ac/dc conversion module 1 may perform harmonic decomposition on the input current to determine the compensation current, or the ac/dc conversion module 1 may also determine the compensation current by calculating according to the actual output power of the charging module 10 and the phase voltage of the power supply device, and the ac/dc conversion module 1 further provides the compensation current to enable the output current of the power supply device 30 to be passively adjusted, so that the power supply device 30 can output a corresponding ideal target current.

In actual use, the ac/dc conversion module 1 may perform harmonic suppression on the output current of the power supply device 30, and also perform peak clipping and valley filling on the electric energy provided by the power supply device 30, for example, the ac/dc conversion module 1 may perform electric energy storage when the capacity power of the power supply device 30 is greater than the required power of the load, or perform power supplement when the capacity power of the power supply device 30 is less than the required power of the load. It should be understood that the capacity power of the power supply device 30 in the embodiment of the present application refers to the total capacity power of the power supply device 30, and accordingly, the capacity power of the single-phase power is 1/3 of the total capacity power.

In an exemplary embodiment, the ac-dc conversion module 1 may further perform the following steps before determining the compensation current:

S111, acquiring the actual output power of the charging module 10 and the phase of each phase of electricity of the power supply equipment 30;

s112, determining the target current based on the actual output power and/or the capacity power of the power supply device 30, the phase voltage of the power supply device 30, and the phase of the corresponding phase voltage.

The method for the ac/dc conversion module 1 to obtain the actual output power of the charging module 10, the phase voltage of the power supply device 30, and the phase of the corresponding phase voltage can be referred to the description of the above embodiment, and will not be repeated here. The capacity power of the power supply device 30 is the maximum allowable output power of the power supply device 30, and after the power supply device 30 determines, the capacity power is a fixed value.

The target current is the final output current of each phase of the power supply device 30, and is the ideal current output after harmonic treatment according to the input current of the charging module 10, so when the power supply device 30 outputs the target current, the active power provided by the power supply device 30 to the charging system is increased, and the power factor of the charging system can be improved.

As described above, the phase voltage of the power supply apparatus 30 according to the embodiment of the present application refers to the phase voltage effective value of single-phase power. The method for determining the target current in step S112 will be further described below in connection with the specific case.

In an alternative embodiment of the present application, if the actual output power is smaller than the capacity power, and no power scheduling is performed at this time, only harmonic suppression is performed, that is, when there is surplus power in the power supply device 30, the ac/dc conversion module 1 does not charge the energy storage battery 22 in the energy storage device 20, but only harmonic suppression is performed on the output current of the power supply device 30. In this case, the ac/dc conversion module 1 may calculate the phase current effective value of each phase of electricity of the power supply device 30 according to the following formula after acquiring the actual output power of the charging module 10:

Irms＝Po/Vrms (1)

wherein: po is the actual output power of the charging module 10, vrms is the phase voltage effective value of the power supply device 30, and Irms is the phase current effective value of a certain phase of the power supply device 30.

After determining the phase current effective value, the ac/dc conversion module 1 may further calculate the target current of the power supply device 30 corresponding to the phase current according to the following formula:

Ia＝1.414*Irms*sin(θ) (2)

wherein: ia is a target current of the power supply apparatus 30 corresponding to the phase electricity, irms is a phase current effective value of the power supply apparatus 30 corresponding to the phase electricity, and θ is a phase of the corresponding phase electricity.

On the basis of this, the ac/dc conversion module 1 further determines the difference between the input current of the charging module 10 and the target current as a compensation current, and supplies the compensation current. The compensation current can be obtained by the following relationship:

Ia2＝Ia1-Ia (3)

Wherein: ia2 is the compensation current, ia1 is the input current of the charging module 10, and Ia is the target current of the corresponding phase electricity of the power supply device 30.

In another alternative embodiment of the present application, if the actual output power is greater than the capacity power, and at this time, both harmonic suppression and power scheduling are performed, that is, when the power supply device 30 has a power gap, the ac/dc conversion module 1 uses the energy storage battery 22 in the energy storage device 20 to compensate the power gap, specifically, the ac/dc conversion module 1 determines the difference between the capacity power and the actual output power as the second differential power, and the ac/dc conversion module 1 further controls the energy storage battery 22 in the energy storage device 20 to provide the second differential power to the charging module 10. It should be understood that the charging and discharging of the energy storage battery 22 can be regarded as superposition of the fundamental component output by the power supply device 30, that is, equivalent to the synchronous harmonic treatment of the output current of the power supply device 30 by the ac/dc conversion module 1. In this case, the ac/dc conversion module 1 may perform the following steps to determine the target current:

s113, determining a phase current effective value based on the capacity power and the phase voltage;

and S114, determining a target current based on the phase current effective value and the phase of the corresponding phase.

The ac-dc conversion module 1 may determine the phase current effective value based on the following formula:

Irms_max＝Po_max/3*Vrms (4)

wherein: po_max is the capacity power of the power supply device 30, vrms is the phase voltage effective value of the power supply device 30, and Irms_max is the phase current effective value of the corresponding phase of the power supply device 30.

After determining the phase current effective value, the ac/dc conversion module 1 may further calculate the target current of the corresponding phase of the power supply device 30 according to the following formula:

Ia_max＝1.414*Irms_max*sin(θ) (5)

wherein: ia_max is a target current of the corresponding phase of the power supply apparatus 30, irms_max is a phase current effective value of the corresponding phase of the power supply apparatus 30, and θ is a phase of the corresponding phase electricity.

On the basis of this, the ac/dc conversion module 1 further determines the difference between the input current of the charging module 10 and the target current as a compensation current, thereby further providing the compensation current. The compensation current can be obtained by the following relationship:

Ia2＝Ia1-Ia_max (6)

wherein: ia2 is the compensation current, ia1 is the input current of the charging module 10, and ia_max is the target current of the corresponding phase of the power supply device 30.

In still another alternative embodiment of the present application, if the actual output power is smaller than the capacity power, and at this time, both harmonic suppression and power scheduling are performed, that is, when there is surplus power in the power supply device 30, the ac/dc conversion module 1 may charge the energy storage battery 22 in the energy storage device 20 with the surplus power to perform power scheduling, specifically, because the actual output power of the charging module 10 is smaller than the capacity power of the power supply device 30, the ac/dc conversion module 1 may determine the difference between the capacity power and the actual output power as the first differential power, and then control the power supply device 30 to charge the energy storage battery 22 in the energy storage device 20 based on the first differential power. For example, when the electricity price is cheap at night or the electricity consumption is low, the ac/dc conversion module 1 may charge the energy storage battery 22 based on the first differential power, and then control the energy storage battery 22 to discharge when the electricity price is high or the electricity consumption is high, so that the economic benefit of the electricity price differential charging system can be increased or the effect of power compensation can be achieved. In this case, the ac/dc conversion module 1 may perform the following steps to determine the target current for harmonic remediation:

S115, determining a phase current effective value based on the actual output power and the phase voltage parameter;

s116, determining a target current based on the phase current effective value and the phase of the corresponding phase;

s117, determining a charging current of the energy storage battery based on the capacity power of the power supply equipment, the actual output power and the charging power of the energy storage battery;

and S118, determining a compensation current based on the input current, the target current and the charging current.

The phase current effective value in step S115 may be determined by the above formula (1), and the target current in step S116 may be determined by the above formula (2), which is not described herein.

In step S117, the charging current is the current of the ac/dc conversion module 1 for charging the energy storage battery 22 in the energy storage device 20 by using the surplus power, and it can be known that the maximum charging currents of the energy storage batteries 22 with different capacities are different, so that the ac/dc conversion module 1 can further determine the surplus power according to the capacity power of the power supply device and the actual output power of the charging module, if the surplus power is greater than the charging power of the energy storage battery, the ac/dc conversion module 1 can charge the energy storage battery according to the charging power of the energy storage battery, and at this time, the charging current is the maximum charging current of the energy storage battery, and the ac/dc conversion module 1 can communicate with the BMS system of the energy storage battery 22 to obtain the maximum charging current of the energy storage battery 22. If the surplus power is smaller than the charging power of the energy storage battery, the ac/dc conversion module 1 can charge the energy storage battery according to the surplus power, and at this time, the ac/dc conversion module 1 can determine the charging current according to the following formula:

Ix＝Px/3Vrms (7)

Wherein: px is surplus power, vrms is a phase voltage effective value of the power supply device 30, and Ix is a phase current instantaneous value of the corresponding phase of the power supply device 30, that is, a charging current.

After determining the charging current, in step S118, the ac/dc conversion module 1 further determines the final compensation current according to the following formula:

Ia2＝Ia1-Ia-Ix (8)

wherein: ia2 is the compensation current, ia1 is the input current of the charging module 10, ia is the target current of the corresponding phase electricity of the power supply device 30, and Ix is the charging current.

It should be understood that, in the embodiment of the present application, when power scheduling is performed, the ac/dc conversion module 1 should take the supply of the compensation current as the highest priority, that is, when power scheduling is performed, the ac/dc conversion module 1 should take the priority of supplying the compensation current for power factor management, and then perform power scheduling on the energy storage battery 22 according to the apparent power margin of the power supply device 30.

The foregoing description is only of the preferred embodiments of the present application, and is not intended to limit the scope of the claims, and all equivalent structures or equivalent processes using the descriptions and drawings of the present application, or direct or indirect application in other related technical fields are included in the scope of the claims of the present application.

Claims (17)

1. A charging control method, characterized by comprising:

acquiring input current of a charging module;

determining a compensation current based on the input current;

and adjusting the output current of a power supply device based on the compensation current, wherein the power supply device is connected with the input side of the charging module.

2. The charge control method according to claim 1, characterized in that the determining of the compensation current based on the input current includes:

acquiring actual output power and phase voltage parameters of the charging module;

if the actual output power is smaller than the capacity power of the power supply equipment, determining a target current based on the actual output power and the phase voltage parameter;

a compensation current is determined based on the target current and the input current.

3. The charge control method according to claim 1, characterized in that the determining of the compensation current based on the input current includes:

acquiring actual output power and phase voltage parameters of the charging module;

if the actual output power is smaller than the capacity power of the power supply equipment, determining a target current based on the actual output power and the phase voltage parameter;

determining a charging current to an energy storage battery based on the capacity power, the actual output power, and a charging power of the energy storage battery;

A compensation current is determined based on the input current, the target current, and the charging current.

4. A charge control method according to claim 2 or 3, wherein the phase voltage parameter includes a phase voltage and a phase of a corresponding phase; said determining a target current based on said actual output power and said phase voltage parameter comprises:

determining a phase current effective value based on the actual output power and the phase voltage;

the target current is determined based on the phase current effective value and the phase of the corresponding phase.

5. The charge control method according to claim 2, characterized in that the determining a compensation current based on the input current includes:

acquiring actual output power and phase voltage parameters of the charging module;

if the actual output power is greater than the capacity power, determining a target current based on the capacity power and the phase voltage parameter;

a compensation current is determined based on the target current and the input current.

6. The charge control method according to claim 5, wherein the phase voltage parameter includes a phase voltage and a phase of a corresponding phase; the determining a target current based on the capacity power and the phase voltage parameter includes:

Determining a phase current effective value based on the capacity power and the phase voltage;

a target current is determined based on the phase current effective value and the phase of the corresponding phase.

7. The charge control method according to claim 1, characterized in that the determining of the compensation current based on the input current includes:

determining a fundamental component and a harmonic component of the input current;

a compensation current is determined based on the fundamental component and the harmonic component.

8. An ac-dc conversion module, characterized in that the ac-dc conversion module comprises an ac-dc conversion unit and a control unit connected thereto, the ac-dc conversion unit being connected to the input side of the charging module, the control unit being adapted to perform the charging control method according to any one of claims 1-7.

9. The ac to dc conversion module according to claim 8, wherein the control unit is configured to: acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is smaller than the capacity power of the power supply equipment, determining a target current based on the actual output power and the phase voltage parameter; determining a compensation current based on the target current and the input current; or,

Acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is smaller than the capacity power, determining a target current based on the actual output power and the phase voltage parameter; determining a charging current to an energy storage battery based on a capacity power of the power supply device, the actual output power, and a charging power of the energy storage battery; a compensation current is determined based on the input current, the target current, and the charging current.

10. The ac to dc conversion module of claim 8, wherein the control unit is further configured to: acquiring actual output power and phase voltage parameters of the charging module; if the actual output power is larger than the capacity power of the power supply equipment, determining a target current based on the capacity power and the phase voltage parameter; a compensation current is determined based on the target current and the input current.

11. An energy storage device, comprising:

the ac-dc conversion module of any one of claims 8-10;

the energy storage battery is connected with the alternating current-direct current conversion module;

wherein the energy storage device is at least for: and determining a difference power based on the capacity power of the power supply equipment and the actual output power of the charging module, and performing power scheduling based on the difference power.

12. A charging system, comprising:

the ac-dc conversion module of any one of claims 8-10;

and the charging module is connected with the power supply equipment and is used for providing direct-current charging voltage for a load connected with the power supply equipment by utilizing the alternating-current voltage output by the power supply equipment.

13. The charging system of claim 12, wherein the charging module comprises:

the natural rectification unit is connected with the power supply equipment and is used for rectifying alternating voltage provided by the power supply equipment into direct voltage;

the filtering unit is connected with the natural rectifying unit and is used for filtering the direct-current voltage and inhibiting a current peak value;

and the isolation DC/DC unit is connected with the filtering unit and is used for carrying out voltage conversion on the filtered direct-current voltage.

14. The charging system of claim 13, wherein the natural rectification unit comprises a rectification bridge, and the filtering unit comprises an inductive reactance subunit and a capacitive reactance subunit;

the input end of the rectifier bridge is connected with the power supply equipment, one end of the inductive reactance subunit is connected with the first output end of the rectifier bridge, the other end of the inductive reactance subunit is connected with one end of the capacitive reactance subunit, and the other end of the capacitive reactance subunit is connected with the second output end of the rectifier bridge; or the inductive reactance subunit is connected in series between the rectifier bridge and the power supply equipment, and the capacitive reactance subunit is connected in parallel with two output ends of the rectifier bridge.

15. The charging system of claim 14, wherein the rectifier bridge comprises a first leg, a second leg, and a third leg arranged in parallel, and wherein the first leg to the third leg each comprise an upper half-bridge and a lower half-bridge; the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm are respectively and correspondingly connected with a phase voltage output end, the first output end of the first bridge arm, the first output end of the second bridge arm and the first output end of the third bridge arm are respectively connected with one end of the inductive reactance subunit, the second output end of the first bridge arm, the second output end of the second bridge arm and the second output end of the third bridge arm are respectively connected with one end of the capacitive reactance subunit, and the other end of the capacitive reactance subunit is connected with the other end of the inductive reactance subunit.

16. The charging system of claim 14, wherein the rectifier bridge comprises a first leg, a second leg, and a third leg arranged in parallel, and wherein the first leg to the third leg each comprise an upper half-bridge and a lower half-bridge; the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm are all connected with a phase voltage output end through an inductive reactance subunit, the first output end of the first bridge arm, the first output end of the second bridge arm and the first output end of the third bridge arm are respectively connected with one end of the capacitive reactance subunit, and the second output end of the first bridge arm, the second output end of the second bridge arm and the second output end of the third bridge arm are respectively connected with the other end of the capacitive reactance subunit.

17. Charging system according to claim 14, wherein the rectifier bridge comprises a rectifier diode and/or a thyristor.