A charging station-oriented port sharing type flexible capacity expansion device and an operation method thereof

Abstract

The application relates to a charging station-oriented port sharing type flexible capacity expansion device and an operation method thereof. The method comprises the following steps: acquiring initial modulation signals of a first independent port module and a second independent port module respectively; determining an equivalent modulation signal according to the initial modulation signals and a preset vector synthesis strategy; determining a target switch combination of a shared port module according to a comparison result of an amplitude of the equivalent modulation signal and preset positive and negative voltage thresholds; controlling the conduction or turn-off of each power device in the shared port module according to the target switch combination, so as to obtain a first output voltage of the shared port module; and determining second output voltages of the first independent port module and the second independent port module respectively according to the initial modulation signals and the first output voltage. The method can reduce the hardware configuration cost of the super charging station flexible capacity expansion device.

Description

Technical Field

[0001] This application relates to the field of charging station technology, and in particular to a port-sharing flexible capacity expansion device for charging stations and its operation method. Background Technology

[0002] With the large-scale application of ultra-fast charging technology for electric vehicles, supercharging stations, due to their short-term concentrated ultra-high power demand, are putting significant pressure on the power supply capacity of existing power distribution networks. To dynamically increase the power supply capacity of supercharging stations without upgrading the main transformer and primary grid infrastructure, flexible capacity expansion technology based on power electronic conversion has become an effective solution. These devices are typically connected in parallel to the low-voltage side of the transformer, achieving flexible expansion of system capacity through real-time compensation or the provision of additional active power.

[0003] Currently, the mainstream power electronic topologies for achieving this type of flexible capacity expansion generally employ traditional two-level or three-level voltage source converters connected back-to-back. In this architecture, the AC / DC converter and the DC / AC converter are independent of each other, coupled through a shared DC bus to form two completely independent power conversion channels.

[0004] However, the aforementioned back-to-back structure requires two complete sets of fully controlled power switch bridge arms and two corresponding drive and protection circuits, resulting in a significant increase in the number of key power devices. Power semiconductor devices and their associated circuits are the core cost source of the device; their increased quantity directly leads to a rise in the overall cost, hindering the large-scale application of flexible capacity expansion devices in commercial supercharging stations. Summary of the Invention

[0005] Therefore, it is necessary to address the aforementioned technical problems by providing a port-sharing flexible capacity expansion device for charging stations and its operation method, which can reduce the redundant configuration of power devices and supporting circuits and improve the power density of the flexible capacity expansion device.

[0006] In a first aspect, this application provides an operation method for a port-sharing flexible capacity expansion device for charging stations, applied to a controller of the port-sharing flexible capacity expansion device. The port-sharing flexible capacity expansion device further includes a shared port module, a first independent port module, and a second independent port module. The controller is electrically connected to the shared port module, the first independent port module, and the second independent port module, respectively. The shared port module includes a positive DC bus, a negative DC bus, and a first DC capacitor and a second DC capacitor connected in series between the positive DC bus and the negative DC bus. The method includes:

[0007] The initial modulation signals of the first independent port module and the second independent port module are acquired respectively;

[0008] Based on the initial modulation signal and the preset vector synthesis strategy, the equivalent modulation signal is determined;

[0009] Based on the comparison results between the amplitude of the equivalent modulation signal and the preset positive voltage threshold and negative voltage threshold, the target switch combination of the shared port module is determined. The preset positive voltage threshold and negative voltage threshold are determined by the rated voltage of the first DC capacitor or the second DC capacitor and a preset ratio.

[0010] The first output voltage of the shared port module is obtained by controlling the conduction or cutoff of each power device in the shared port module according to the target switch combination.

[0011] Based on the initial modulation signal and the first output voltage, the second output voltage of each of the first independent port module and the second independent port module is determined.

[0012] In one embodiment, acquiring the initial modulation signals of the first independent port module and the second independent port module respectively includes:

[0013] Obtain the amplitude and phase of the initial modulation signal of the first independent port module, and the amplitude and phase of the initial modulation signal of the second independent port module;

[0014] The step of determining the equivalent modulation signal based on the initial modulation signal and a preset vector synthesis strategy includes:

[0015] The amplitude and phase of the initial modulation signals of the first independent port module and the second independent port module are vector synthesized to obtain the amplitude and phase of the equivalent modulation signal.

[0016] In one embodiment, the negative terminal of the first DC capacitor and the positive terminal of the second DC capacitor are connected to a reference ground; the shared port module further includes a three-phase branch, each phase of which includes a first power device, a second power device, a third power device, and a fourth power device of the shared port module connected in series between the positive DC bus and the negative DC bus, and a bidirectional switch branch formed by a fifth power device and a sixth power device of the shared port module connected in series; determining the target switch combination of the shared port module based on the comparison result of the amplitude of the equivalent modulation signal with preset positive voltage thresholds and negative voltage thresholds includes:

[0017] When the amplitude of the equivalent modulation signal is greater than a preset positive voltage threshold, the first power device and the fifth power device of the shared port module are turned on.

[0018] When the amplitude of the equivalent modulation signal is less than a preset negative voltage threshold, the fourth and sixth power devices of the shared port module are turned on.

[0019] When the amplitude of the equivalent modulation signal is not greater than a preset positive voltage threshold and not less than a preset negative voltage threshold, the second and fifth power devices of the shared port module are turned on, or the third and sixth power devices of the shared port module are turned on.

[0020] In one embodiment, determining the second output voltage of each of the first independent port module and the second independent port module based on the initial modulation signal and the first output voltage includes:

[0021] The first output voltage is subtracted from the initial modulation signal of the first independent port module and the initial modulation signal of the second independent port module, respectively, to obtain the second output voltage of the first independent port module and the second independent port module.

[0022] In one embodiment, the step of controlling the on / off state of each power device in the shared port module according to the target switch combination to obtain the first output voltage of the shared port module includes:

[0023] Generate a corresponding drive signal based on the target switch combination;

[0024] The driving signal controls the corresponding power device in the shared port module to turn on or off, so that the shared port module outputs a level corresponding to the target switch combination, thereby obtaining a first output voltage.

[0025] Secondly, this application also provides a port-sharing flexible capacity expansion device for charging stations, comprising:

[0026] Shared port module, first independent port module, second independent port module, filter inductor and controller;

[0027] The shared port module includes a positive DC bus, a negative DC bus, and a first DC capacitor and a second DC capacitor connected in series between the positive DC bus and the negative DC bus. The negative terminal of the first DC capacitor and the positive terminal of the second DC capacitor are connected to a reference ground. The shared port module also includes a three-phase branch. Each phase of the three-phase branch includes a first power device, a second power device, a third power device, and a fourth power device of the shared port module connected in series between the positive DC bus and the negative DC bus, and a bidirectional switch branch formed by the fifth power device and the sixth power device of the shared port module connected in series.

[0028] The first independent port module and the second independent port module each include a single-phase full-bridge circuit composed of four power devices;

[0029] The connection nodes of the fifth power device and the sixth power device are respectively connected to the connection nodes of the seventh power device and the eighth power device of the single-phase full-bridge circuit in the first independent port module and the second independent port module, and the connection nodes of the ninth power device and the tenth power device of the single-phase full-bridge circuit in the first independent port module and the second independent port module are respectively connected to the AC bus of the charging station through the filter inductor.

[0030] The shared port module is used to provide multi-level voltage to the first independent port module and the second independent port module through the bidirectional switch branch;

[0031] The controller is electrically connected to the shared port module, the first independent port module, and the second independent port module, respectively, and the controller is used to implement the steps of the method described above when executing the program.

[0032] In one embodiment, the single-phase full-bridge circuit further includes a DC capacitor, with the collectors of the seventh power device and the ninth power device respectively connected to the positive terminal of the DC capacitor, and the emitters of the eighth power device and the tenth power device respectively connected to the negative terminal of the DC capacitor.

[0033] In one embodiment, the collector of the first power device of the shared port module is connected to the positive DC bus, the emitter of the first power device is connected to the collector of the second power device, the emitter of the second power device is connected to the collector of the third power device, the emitter of the third power device is connected to the collector of the fourth power device, and the emitter of the fourth power device is connected to the negative DC bus.

[0034] In one embodiment, in the bidirectional switch branch, the collector of the fifth power device is connected to the connection node between the first power device and the second power device, the emitter of the fifth power device is connected to the collector of the sixth power device, and the emitter of the sixth power device is connected to the connection node between the third power device and the fourth power device.

[0035] In one embodiment, the three-phase branch includes a phase a branch, a phase b branch, and a phase c branch, wherein the phase a branch, the phase b branch, and the phase c branch are respectively connected to phase A, phase B, and phase C of the AC bus.

[0036] Thirdly, this application also provides an electronic device, including a memory and a processor, wherein the memory stores a program, and the processor executes the program to implement the steps of the method described in any of the preceding claims.

[0037] Fourthly, this application also provides a readable storage medium having a program stored thereon, which, when executed by a processor, implements the steps of the method described in any of the preceding claims.

[0038] Fifthly, this application also provides a program product, including a program that, when executed by a processor, implements the steps of the method described in any of the preceding claims.

[0039] The aforementioned port-sharing flexible capacity expansion device and its operation method for charging stations determine the output state of the shared port module based on the modulation requirements of the two independent port modules. After the shared port module forms a common voltage, the remaining voltage required by each of the two independent port modules is determined, enabling the two independent port modules to jointly utilize the shared port module to complete part of the voltage conversion. Therefore, while meeting the output requirements of the two independent ports, the redundant configuration of power devices and supporting circuits required by configuring complete common voltage conversion channels for each port can be reduced. Attached Figure Description

[0040] To more clearly illustrate the technical solutions in the embodiments of this application or related technologies, the drawings used in the description of the embodiments of this application or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a schematic diagram of a back-to-back structured two-level flexible capacity expansion device in related technologies.

[0042] Figure 2 This is a schematic diagram of a back-to-back structured three-level flexible capacity expansion device in related technologies.

[0043] Figure 3 This is a flowchart illustrating the operation method of a port-sharing flexible capacity expansion device for charging stations in one embodiment.

[0044] Figure 4 This is a flowchart illustrating the operation method of a port-sharing flexible capacity expansion device for charging stations in another embodiment.

[0045] Figure 5 This is a schematic diagram of a port-sharing flexible capacity expansion device for a charging station in one embodiment;

[0046] Figure 6This is a schematic diagram of a port-sharing flexible capacity expansion device for charging stations in another embodiment;

[0047] Figure 7 This is a structural block diagram of a port-sharing flexible capacity expansion device for charging stations in one embodiment. Detailed Implementation

[0048] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0049] It should be noted that the terms "first," "second," etc., used in this application can be used to describe various elements, but these elements are not limited by these terms. These terms are only used to distinguish the first element from the second element. The terms "comprising" and "having," and any variations thereof, used in this application, are intended to cover non-exclusive inclusion. The term "multiple" used in this application refers to two or more. The term "and / or" used in this application refers to one of the embodiments, or any combination of multiple embodiments.

[0050] In related technologies, mainstream power electronic topologies that achieve flexible capacity expansion generally adopt a back-to-back structure. Please refer to... Figure 1 and Figure 2 , Figure 1 This refers to a back-to-back structured two-level flexible capacity expansion device in related technologies. Figure 2 This refers to a back-to-back structured three-level flexible capacity expansion device in related technologies. For example... Figure 1 As shown, the two-level voltage source converters are connected back-to-back. The AC / DC converter and the DC / AC converter are independent of each other, coupled through a common DC bus, forming two completely independent power conversion channels. Based on this, as... Figure 2 As shown, to further improve the output voltage waveform quality, related technologies have also proposed a back-to-back structure that replaces the two converters on both sides with three-level voltage source converters. However, the aforementioned back-to-back structure still faces bottlenecks in terms of hardware cost and system complexity.

[0051] (1) Regardless of whether it is a two-level or three-level structure, two complete sets of fully controlled power switch bridge arms, two corresponding drive and protection circuits, and DC support capacitor banks are required. Power semiconductor devices and their supporting circuits are the core cost source of the device, and their increased quantity directly leads to an increase in the overall cost.

[0052] (2) Both converters need to independently handle the high-frequency switching conversion of the full power, resulting in high overall switching and conduction losses. At the same time, the two power units also increase the pressure on heat dissipation design and the demand for filtering components, leading to an increase in system size, weight and thermal management complexity.

[0053] Based on this, in an exemplary embodiment, an operation method for a port-sharing flexible capacity expansion device for charging stations is provided. The method is applied to a controller of the port-sharing flexible capacity expansion device. The port-sharing flexible capacity expansion device further includes a shared port module, a first independent port module, and a second independent port module. The controller is electrically connected to the shared port module, the first independent port module, and the second independent port module, respectively. The shared port module includes a positive DC bus, a negative DC bus, and a first DC capacitor and a second DC capacitor connected in series between the positive DC bus and the negative DC bus.

[0054] For example, a port-shared flexible capacity expansion device includes at least two independent port modules (i.e., a first independent port module and a second independent port module) and a filter inductor. The two independent port modules are respectively used to connect to the power grid and the load terminal, and the shared port module is electrically connected to both independent port modules. The port-shared flexible capacity expansion device is configured to provide a common voltage to the two independent port modules through the shared port module. The shared port module includes at least one set of switching networks composed of multiple power switching devices, and the independent port modules include single-phase full-bridge circuits composed of fully controlled power switching devices. The controller has signal acquisition, vector operation, and pulse width modulation (PWM) drive signal generation functions to coordinate and control the on / off timing of the power devices in each module.

[0055] like Figure 3 As shown, the method includes:

[0056] Step 110: Obtain the initial modulation signals of the first independent port module and the second independent port module respectively.

[0057] The initial modulation signal can be an AC reference waveform that characterizes the target voltage value expected to be output by each independent port module, and it contains at least voltage amplitude information and frequency and phase information. This signal reflects the basic power transmission task that each independent port module needs to undertake based on the current grid conditions and load requirements.

[0058] For example, voltage and current data from the grid side and the load side can be acquired in real time using voltage and current sensors. Based on preset power outer loop control and current inner loop control algorithms, the original sinusoidal modulation wave corresponding to the independent port module can be calculated and generated. The controller can perform the above calculation independently for the first and second independent port modules respectively, so as to acquire two sets of independent initial modulation signals in parallel.

[0059] Optionally, for different charging conditions, the controller can pre-store corresponding modulation signals. When the current charging mode switch is detected, the controller can retrieve the initial modulation signal parameters that match the mode from the preset voltage setpoint table and use them as the initial modulation signal of the independent port module.

[0060] Step 120: Determine the equivalent modulation signal based on the initial modulation signal and the preset vector synthesis strategy.

[0061] Vector synthesis strategy can refer to the rules for performing vector superposition operations on two independent AC modulation signals as vector quantities in a complex plane or polar coordinate system. The equivalent modulation signal can be used to characterize the total voltage stress or total output target that the shared port module needs to bear.

[0062] For example, the instantaneous amplitude and real-time phase angle of the two initial modulation signals can be extracted separately; then, based on the parallelogram vector superposition rule, trigonometric function operations are used to combine the amplitude and phase of the two signals to obtain the composite amplitude and composite phase angle of the equivalent modulation signal.

[0063] Alternatively, the vector synthesis strategy can also be implemented using coordinate transformation.

[0064] Step 130: Based on the comparison results between the amplitude of the equivalent modulation signal and the preset positive voltage threshold and negative voltage threshold, determine the target switch combination of the shared port module. The preset positive voltage threshold and negative voltage threshold are determined by the rated voltage of the first DC capacitor or the second DC capacitor and a preset ratio.

[0065] The target switch combination can refer to a specific set of on / off logic states of multiple power devices within a shared port module, determined to achieve the amplitude output requirement of the equivalent modulation signal at the current moment. The positive and negative voltage thresholds can be two symmetrical or asymmetrical voltage comparison points obtained by multiplying the rated value of a single DC capacitor voltage by a preset scaling factor.

[0066] For example, the real-time instantaneous value of the obtained equivalent modulation signal can be compared with the aforementioned positive voltage threshold and negative voltage threshold. If the amplitude of the equivalent modulation signal is higher than the positive voltage threshold, it is determined that the shared port module needs to output a positive high voltage level, and a set of switch combinations for generating the positive level is determined; if the amplitude of the equivalent modulation signal is lower than the negative voltage threshold, it is determined that a negative high voltage level needs to be output, and a set of switch combinations for generating the negative level is determined; if the amplitude of the equivalent modulation signal is between the two thresholds, it is determined that the shared port module needs to output a zero level or a low voltage level, and a set of switch combinations for generating the zero level is determined.

[0067] Optionally, the preset positive voltage threshold and negative voltage threshold can be dynamically adjusted according to the overall power level of the current device: under light load conditions, the values ​​of the preset positive voltage threshold and negative voltage threshold are increased to delay the intervention of the shared port module, so as to further reduce the switching losses under light load conditions; under heavy load conditions, the values ​​of the preset positive voltage threshold and negative voltage threshold are decreased to allow the shared port module to intervene earlier, so as to ensure the rapid response capability under heavy load conditions.

[0068] Step 140: Control the on or off of each power device in the shared port module according to the target switch combination to obtain the first output voltage of the shared port module.

[0069] For example, based on a determined target switching combination, a corresponding PWM drive pulse signal can be generated by calling an internally stored mapping table or performing real-time logic decoding. This drive signal is then amplified by the drive circuit and applied to the control terminals (e.g., gate or base) of the corresponding power devices in the shared port module to control these power devices to turn on or off in the sequence defined by the target combination. The internal circuit structure of the shared port module responds to the switching action of the power devices, synthesizing a first output voltage with a corresponding amplitude at the output node and coupling this voltage to the two independent port modules.

[0070] Optionally, the level states corresponding to the target switch combination can be mapped to basic vectors in the spatial vector diagram. By calculating the duration of each basic vector and synthesizing the target reference vector, the corresponding switch drive timing can be generated.

[0071] Step 150: Determine the second output voltage of the first independent port module and the second independent port module respectively based on the initial modulation signal and the first output voltage.

[0072] For example, the initial modulation signal of the first independent port module can be subtracted from the first output voltage of the shared port module, that is, the first output voltage can be subtracted from the original target voltage of the first independent port module to obtain the second output voltage that the first independent port module needs to bear independently; similarly, the initial modulation signal of the second independent port module can be subtracted from the first output voltage to obtain the second output voltage that the second independent port module needs to bear independently; then, these two second output voltages are used as modulation waves to drive the full-bridge circuits of the two independent port modules to output the corresponding compensation voltages.

[0073] Optionally, the two second output voltages can be calculated in parallel within the same control cycle to avoid phase deviation between the two ports caused by the time delay introduced by serial calculation.

[0074] In the aforementioned operation method of the port-sharing flexible capacity expansion device for charging stations, the output state of the shared port module is determined based on the modulation requirements of the two independent port modules. After the shared port module forms a common voltage, the remaining voltage required by each of the two independent port modules is determined, enabling the two independent port modules to jointly utilize the shared port module to complete part of the voltage conversion. Therefore, while meeting the output requirements of the two independent ports, the redundant configuration of power devices and supporting circuits required by configuring complete common voltage conversion channels for each port can be reduced.

[0075] In one exemplary embodiment, step 110 includes:

[0076] Step 110A: Obtain the amplitude and phase of the initial modulation signal of the first independent port module, and the amplitude and phase of the initial modulation signal of the second independent port module.

[0077] Further, step 120 includes:

[0078] Step 120A: Perform vector synthesis on the amplitude and phase of the initial modulation signals of the first independent port module and the second independent port module to obtain the amplitude and phase of the equivalent modulation signal.

[0079] For example, the amplitude U of the modulation signal from the first independent port module (port 1) and the second independent port module (port 2) can be acquired. xp1ref and U xp2ref And acquire the phase φ of the modulated signal. x1ref and φ x2ref The initial modulation signal is obtained; then, the phase φ of the equivalent modulation signal is calculated according to the following formulas (1) and (2). xc With amplitude U xpref :

[0080] (1)

[0081] (2)

[0082] Among them, U dc This is the rated voltage of either the first or second DC capacitor. Furthermore, based on the calculated amplitude and phase of the equivalent modulation signal, the equivalent modulation signal U is obtained. xref =U xpref ∠φ xpref .

[0083] In this embodiment, by synthesizing the amplitude and phase of the modulation signals of two independent port modules according to a preset strategy, a unified equivalent modulation signal for selecting the switching state of the shared port module is obtained, which enables the switching state of the shared port module to be determined simultaneously based on the modulation information of the two ports.

[0084] In an exemplary embodiment, the negative terminal of the first DC capacitor and the positive terminal of the second DC capacitor are connected to a reference ground; the shared port module further includes a three-phase branch, each phase of which includes a first power device, a second power device, a third power device, and a fourth power device of the shared port module connected in series between the positive DC bus and the negative DC bus, and a bidirectional switch branch formed by the fifth and sixth power devices of the shared port module connected in series, wherein the first power device can be represented as S. x1 The second power device can be represented as S x2 The third power device can be represented as S x3 The fourth power device can be represented as S x4 The fifth power device can be represented as S x5 The sixth power device can be represented as S x6 The preset ratio can be 1 / 2; Step 130 includes:

[0085] Step 130A: When the amplitude of the equivalent modulation signal is greater than the preset positive voltage threshold, control the first power device and the fifth power device of the shared port module to turn on.

[0086] For example, when the equivalent modulation signal U xref The amplitude is greater than U dc / 2, i.e., U xref >U dc / 2, control S x1 and S x5 Conduction. Thus, due to S x1 After conduction, the high potential of the positive DC bus is introduced, S x5 The conduction transfers the potential to the output node, thereby forming a positive high voltage level at the output node.

[0087] Step 130B: When the amplitude of the equivalent modulation signal is less than the preset negative voltage threshold, control the fourth power device and the sixth power device of the shared port module to turn on.

[0088] For example, when the equivalent modulation signal U xref The amplitude is less than -U dc / 2, i.e., U xref <-U dc / 2, control S x4 and S x6 Conduction. Thus, due to S x4 After conduction, the low potential of the negative DC bus is introduced, S x6 The conduction transfers the potential to the output node, thereby creating a negative high voltage level at the output node.

[0089] Step 130C: When the amplitude of the equivalent modulation signal is not greater than a preset positive voltage threshold and not less than a preset negative voltage threshold, control the second power device and the fifth power device of the shared port module to turn on, or control the third power device and the sixth power device of the shared port module to turn on.

[0090] For example, when the equivalent modulation signal U xref The amplitude is not greater than U dc / 2 is not less than -U dc / 2, i.e., -U dc / 2≤U xref ≤U dc / 2, Controller controls S x2 and S x5 To conduct, or control S x3 and S x6 Conduction. Thus, due to S x2 After conduction, via S x5 The midpoint potential (reference ground potential) of the first DC capacitor and the second DC capacitor is transferred to the output node, or, S x3 After conduction, via S x6 The same reference ground potential is passed to the output node, thereby creating a zero level at the output node.

[0091] In one exemplary embodiment, step 150 includes:

[0092] Step 150A: Subtract the first output voltage from the initial modulation signal of the first independent port module and the initial modulation signal of the second independent port module respectively to obtain the second output voltage of the first independent port module and the second independent port module.

[0093] For example, the modulation signal of the first independent port module (port 1) can be subtracted from the output voltage of the shared port module (i.e., the first output voltage) to obtain the second output voltage of the first independent port module (port 1); the modulation signal of the second independent port module (port 2) can be subtracted from the output voltage of the shared port module (i.e., the first output voltage) to obtain the second output voltage of the second independent port module (port 2).

[0094] In this way, since the first output voltage of the shared port module is coupled to both independent port modules, forming a common voltage component shared by the two independent port modules, the remaining voltage to be borne by the two independent port modules can be obtained by subtracting the common voltage formed by the shared port module, thus clarifying the voltage distribution relationship between the shared port module and the two independent port modules.

[0095] In one exemplary embodiment, step 140 includes:

[0096] Step 410: Generate the corresponding drive signal according to the target switch combination.

[0097] The driving signal can refer to the electrical signal used to drive the power device to perform the turn-on or turn-off action, and its level amplitude and timing are matched with the on / off state of each power device defined by the target switch combination.

[0098] Step 420: Control the corresponding power devices in the shared port module to turn on or off according to the drive signal, so that the shared port module outputs a level corresponding to the target switch combination, and obtains the first output voltage.

[0099] For example, a corresponding drive pulse signal can be generated based on the target switch combination of the shared port module; then, the drive signal is applied to the corresponding power devices in the shared port module to control each power device to perform on or off according to the target switch combination; in response to the on or off of each power device, the shared port module synthesizes a level corresponding to the target switch combination at the output node and uses this level as the first output voltage. The connection path between the positive DC bus, negative DC bus, reference ground, and floating node of the shared port module and the output node is determined by the on / off state of each power device; when the power device operates according to the target switch combination, the corresponding potential is guided to the output node, thereby synthesizing a first output voltage with a corresponding level amplitude at the output node and coupling this voltage to the two independent port modules.

[0100] In this way, by converting the target switch combination into the corresponding drive signal for each power device, and establishing the correspondence between the on / off state of the power device and the output level of the shared port module through the drive signal, the corresponding first output voltage can be formed according to the target switch combination.

[0101] In one possible implementation, such as Figure 4 As shown, the operation method of the port-sharing flexible capacity expansion device for charging stations can be executed separately for phases a, b, and c. The following explanation uses any phase x as an example to illustrate the operation process within one control cycle:

[0102] First, the amplitude U of the modulation signal from the first independent port module can be acquired. xp1ref and phase φ x1ref and the modulation signal amplitude U of the second independent port module xp2ref and phase φ x2ref To obtain the initial modulation signals of the first independent port module and the second independent port module, respectively.

[0103] Then, you can follow Figure 4 The preset vector synthesis strategy shown calculates the phase φ of the equivalent modulated signal. xc and amplitude Uxpref Among them, according to formula (1) for φ x1ref With φ x2ref Summing and multiplying by 1 / 2 gives φ. xc According to formula (2), for U xp1ref with U xp2ref Summation, and use 2U dc After normalization, the inverse cosine operation is performed to obtain U. xpref .

[0104] After obtaining φ xc and U xpref After that, you can follow U xref =U xpref ∠φ xc Constructing the equivalent modulation signal U xref and U xref With forward voltage threshold U dc Compare / 2. If U xref >U dc / 2, then determine the first power device S of the shared port module. x1 and the fifth power device S x5 For the target switch combination, and control S x1 and S x5 Conduction.

[0105] If U xref Not greater than U dc / 2, then further U xref With negative voltage threshold -U dc Compare / 2. If U xref <-U dc / 2, then determine the fourth power device S of the shared port module. x4 and the sixth power device S x6 For the target switch combination, and control S x4 and S x6 On; if U xref Not less than -U dc / 2, then determine the second power device S of the shared port module. x2 and the fifth power device S x5 For the target switch combination, or to determine the third power device S x3 and the sixth power device S x6 For the target switch combination.

[0106] The corresponding drive signal can be generated based on the determined target switch combination, and the drive signal can be used to control the corresponding power device in the shared port module to turn on or off, so that the shared port module forms a level corresponding to the target switch combination and obtains the first output voltage of the shared port module.

[0107] After that, according to Figure 4 The voltage distribution process shown involves subtracting the first output voltage of the shared port module from the modulation reference values ​​corresponding to the first independent port module and the second independent port module, respectively, to obtain the second output voltages of the first independent port module and the second independent port module. Figure 4 U in xref1 and U xref2 These represent the modulation reference values ​​corresponding to the two independent port modules, and in this embodiment, they correspond to the initial modulation signals of the first independent port module and the second independent port module, respectively.

[0108] Therefore, in each control cycle, the initial modulation signal acquisition of the two independent port modules, the equivalent modulation signal calculation, the determination of the target switch combination of the shared port module, the formation of the first output voltage, and the determination of the second output voltage of the two independent port modules can be completed sequentially; the next control cycle continues to acquire the corresponding modulation signal and repeat the above process.

[0109] In this way, the port-sharing flexible capacity expansion device is configured to use a switching combination of power devices to increase the DC bus voltage by 2U. dc Converted to +2U dc +U dc , 0, -U dc and -2U dc Five discrete-level output voltages.

[0110] In one exemplary embodiment, such as Figure 5 As shown, a port-sharing flexible capacity expansion device for charging stations is also provided, including a shared port module, a first independent port module, a second independent port module, a filter inductor, and a controller; wherein:

[0111] The shared port module includes a positive DC bus, a negative DC bus, and a first DC capacitor and a second DC capacitor connected in series between the positive DC bus and the negative DC bus. The negative terminal of the first DC capacitor and the positive terminal of the second DC capacitor are connected to a reference ground. The shared port module also includes a three-phase branch. Each phase of the three-phase branch includes a first power device, a second power device, a third power device, and a fourth power device of the shared port module connected in series between the positive DC bus and the negative DC bus, and a bidirectional switch branch formed by the fifth power device and the sixth power device of the shared port module connected in series.

[0112] The first independent port module and the second independent port module each include a single-phase full-bridge circuit composed of four power devices.

[0113] The connection nodes of the fifth and sixth power devices are respectively connected to the connection nodes of the seventh and eighth power devices of the single-phase full-bridge circuit in the first and second independent port modules, and the connection nodes of the ninth and tenth power devices of the single-phase full-bridge circuit in the first and second independent port modules are respectively connected to the AC bus of the charging station through a filter inductor.

[0114] A shared port module is used to provide multi-level voltage to the first independent port module and the second independent port module through a bidirectional switch branch.

[0115] The controller is electrically connected to the shared port module, the first independent port module, and the second independent port module, respectively. When the controller executes the program, it implements the steps of the operation method of the port-sharing flexible capacity expansion device for charging stations in any of the above embodiments.

[0116] For example, Figure 5 Taking phase a branch and the first independent port module and the second independent port module connected to phase a branch as examples, the single-phase topology of the port-sharing flexible capacity expansion device is explained. Figure 5 The two DC capacitors on the left are both denoted by C1. The upper first DC capacitor C1 and the lower second DC capacitor C1 are connected in series. The positive terminal of the first DC capacitor C1 corresponds to the positive DC bus, and the negative terminal of the second DC capacitor C1 corresponds to the negative DC bus. The negative terminal of the first DC capacitor C1 is connected to the positive terminal of the second DC capacitor C1 and then connected to reference ground. For example, the rated voltage of both the first DC capacitor C1 and the second DC capacitor C1 is U. dc Therefore, the positive DC bus and the negative DC bus form positive and negative DC potentials relative to the reference ground, respectively.

[0117] Figure 5 In the shared port module, phase a branch includes the first power device S. a1 Second power device S a2 Third power device S a3 Fourth power device S a4 Fifth power device S a5 and the sixth power device S a6 Among them, the fifth power device S a5 With the sixth power device S a6 Forming a bidirectional switching branch, the fifth power device S a5 With the sixth power device S a6 The connection nodes form a shared port output node V of phase a. coma . Figure 5The single-phase full-bridge circuit at the top right corresponds to the first independent port module, and the single-phase full-bridge circuit at the bottom right corresponds to the second independent port module. Within each independent port module, the seventh, eighth, ninth, and tenth power devices respectively correspond to… Figure 5 The single-phase full-bridge circuit shown includes S1, S2, S3, and S4. The connection nodes of S1 and S2 in both the first and second independent-port modules are connected to the shared port output node V. coma The connection nodes of S3 and S4 in the first independent port module form the a-phase output V of the first port through the filter inductor L. a1 The connection node between S3 and S4 in the second independent port module forms the a-phase output V of the second port through the filter inductor L. a2 .

[0118] For example, the shared port module outputs node V through the shared port. coma It connects to two independent port modules simultaneously. When the controller controls the power devices in the shared port module to turn on or off according to the corresponding switch combinations, the shared port output node V... coma A corresponding first output voltage is formed, which also serves as the common voltage component when the first independent port module and the second independent port module synthesize voltages. The two independent port modules determine their respective required second output voltages based on their initial modulation signals and the first output voltage, and form corresponding voltage components through their respective single-phase full-bridge circuits, thereby achieving voltage synthesis at V... a1 and V a2 The target output is formed at the point. The filter inductor L is set between the output node of each single-phase full-bridge circuit and the AC bus of the charging station to filter the high-frequency components generated during the switching process of the power devices.

[0119] Controller ( Figure 5 (Not shown) is electrically connected to the shared port module, the first independent port module, and the second independent port module, respectively. During operation, the controller acquires the initial modulation signals of the first and second independent port modules according to the steps of the operation method of the port-sharing flexible capacity expansion device for charging stations in any of the above embodiments, determines the equivalent modulation signal and the target switch combination of the shared port module, and outputs corresponding drive signals to coordinate the on / off switching of the power devices of the shared port module and the two independent port modules. Thus, the shared port module undertakes the voltage transformation part shared by the two ports, and the two independent port modules undertake their respective remaining voltage transformation parts.

[0120] The aforementioned port-sharing flexible capacity expansion device for charging stations connects the output node of the shared port module to both the first and second independent port modules simultaneously. The controller coordinates the switching states of the shared port module and the two independent port modules, enabling the two independent ports to share the voltage component formed by the shared port module. This reduces the redundant configuration of power switching devices, corresponding drive circuits, and DC support devices caused by configuring complete common power conversion paths for each port while simultaneously forming two target outputs.

[0121] Optionally, the single-phase full-bridge circuit also includes a DC capacitor, with the collectors of the seventh power device and the ninth power device connected to the positive terminal of the DC capacitor, and the emitters of the eighth power device and the tenth power device connected to the negative terminal of the DC capacitor.

[0122] For example, such as Figure 5 As shown, both the first and second independent port modules are equipped with a DC capacitor C2, and the rated voltage of the DC capacitor C2 can be U. dc For any independent port module, the seventh power device S1 and the eighth power device S2 form the first bridge arm, and the ninth power device S3 and the tenth power device S4 form the second bridge arm. The collectors of the seventh power device S1 and the ninth power device S3 are connected to the positive terminal of the DC capacitor C2, and the emitters of the eighth power device S2 and the tenth power device S4 are connected to the negative terminal of the DC capacitor C2. The midpoint of the first bridge arm, i.e., the connection node between S1 and S2, is connected to the shared port output node V. coma Connection; the midpoint of the second bridge arm, i.e. the connection node between S3 and S4, forms the output of the corresponding independent port through the filter inductor L. Figure 5 In the middle, the output of the upper single-phase full-bridge is V. a1 The output of the single-phase full-bridge bridge below is V. a2 .

[0123] For example, when the rated voltage of DC capacitor C2 is U dc When S2 and S3 in the independent port module are turned on, the independent port module outputs power relative to the shared port output node V. coma It can form +U dc The voltage component; when S1 and S3 are on, or S2 and S4 are on, a 0 voltage component can be formed; when S1 and S4 are on, a -U voltage component can be formed. dc The voltage component.

[0124] In this way, by connecting the DC capacitor C2 to the positive and negative DC terminals of the single-phase full-bridge circuit and switching the polarity of the DC capacitor C2 by using different power device combinations of the two bridge arms, the first independent port module and the second independent port module can respectively form a second output voltage of positive level, zero level or negative level, and combine it with the first output voltage formed by the shared port module.

[0125] In an exemplary embodiment, the collector of the first power device of the shared port module is connected to the positive DC bus, the emitter of the first power device is connected to the collector of the second power device, the emitter of the second power device is connected to the collector of the third power device, the emitter of the third power device is connected to the collector of the fourth power device, and the emitter of the fourth power device is connected to the negative DC bus.

[0126] For example, such as Figure 5 As shown, taking phase a branch as an example, the first power device S of the shared port module a1 Second power device S a2 Third power device S a3 and the fourth power device S a4 The devices are connected in series from the positive DC bus to the negative DC bus. The first power device S... a1 The collector of the device is connected to the positive DC bus, and its emitter is connected to the second power device S. a2 collector connection; second power device S a2 The emitter and the third power device S a3 collector connection; third power device S a3 The emitter and the fourth power device S a4 collector connection; fourth power device S a4 The emitter is connected to the negative DC bus. Combined Figure 5 It can be seen that the second power device S a2 With the third power device S a3 The connection node is at the same potential as the reference ground node between the first DC capacitor C1 and the second DC capacitor C1. Thus, switching paths located above and below the reference ground are formed on the series branch, providing connection nodes for selecting different DC potentials for the bidirectional switching branch.

[0127] Thus, by using the first power device S a1 To the fourth power device S a4 Connected sequentially between the positive and negative DC buses, with the intermediate node aligned with the reference ground midpoint of the DC capacitor, this creates a switching path within the shared port module corresponding to the positive DC potential, reference ground potential, and negative DC potential. This allows the bidirectional switch branch to output node V to the shared port. coma This provides the basis for transmitting different voltage levels.

[0128] In an exemplary embodiment, in the bidirectional switching branch, the collector of the fifth power device is connected to the connection node between the first power device and the second power device, the emitter of the fifth power device is connected to the collector of the sixth power device, and the emitter of the sixth power device is connected to the connection node between the third power device and the fourth power device.

[0129] For example, such as Figure 5 As shown, taking the a-phase branch as an example, the fifth power device S a5 The collector is connected to the first power device S a1 With the second power device S a2 The connection node, the fifth power device S a5 The emitter and the sixth power device S a6 collector connection, sixth power device S a6 The emitter is connected to the third power device S. a3 With the fourth power device S a4 Connection node; Fifth power device S a5 With the sixth power device S a6 The connection node is the shared port output node V. coma Based on this connection, when S a1 and S a5 When connected, the shared port output node V coma Formation + U dc The first output voltage; when S a4 and S a6 When connected, the shared port output node V coma Formation-U dc The first output voltage; when S a2 and S a5 On, or S a3 and S a6 When connected, the shared port output node V coma Corresponding to the reference ground, a first output voltage of 0 is formed. Thus, the shared port module can generate a +U voltage that can be used by both independent port modules. dc 0 or -U dc The voltage component, where the zero level has two selectable switching combinations.

[0130] Thus, by making the fifth power device S a5 and the sixth power device S a6 Serial connection to the shared port output node V coma A bidirectional switch branch is formed, and the two ends of the bidirectional switch branch are respectively connected to the first power device S. a1 With the second power device S a2 The nodes between and the third power device S a3With the fourth power device S a4 The nodes between them can transmit positive potential, reference ground potential, or negative potential to the shared port output node V according to different switch combinations. coma This allows for a shared multilevel voltage to be provided for two independent port modules.

[0131] Furthermore, based on the specific topologies of the shared port module and the two independent port modules described above, different output levels can be formed at the two independent ports through different combinations of the conduction of power devices. The following will continue to use... Figure 5 Taking phase a as an example, where V a1 V represents the output voltage of phase a of the first independent port module. a2 This represents the a-phase output voltage of the second independent port module; the first to sixth power devices in the shared port module are respectively denoted as S. a1 To S a6 The seventh to tenth power devices in the first and second independent port modules are respectively configured according to... Figure 5 Let them be S1 to S4. Since the rated voltage of the first DC capacitor C1, the second DC capacitor C2, and the DC capacitor C2 in the two independent port modules can all be U... dc The first output voltage of the shared port module and the second output voltage formed by the independent port module are combined to achieve V a1 and V a2 The formation includes +2U dc +U dc , 0, -U dc and -2U dc Discrete output levels, including those at the same port. For the same port output level, there can be one or more combinations of power device conduction.

[0132] For example, the conduction combinations corresponding to a positive voltage level can include the following:

[0133] (1) When V a1 =+2U dc And V a2 =+2U dc At that time, the S of the shared port module a1 and S a5 When the circuit is open, S2 and S3 of the first independent port module are open, and S2 and S3 of the second independent port module are open.

[0134] (2) When V a1 =+2U dc And V a2 =+U dc At that time, the S of the shared port module a1 and S a5When the circuit is turned on, S2 and S3 of the first independent port module are turned on, and S1 and S3 of the second independent port module are turned on.

[0135] (3) When V a1 =+2U dc And V a2 =+U dc At that time, the S of the shared port module a1 and S a5 When the circuit is turned on, S2 and S3 of the first independent port module are turned on, and S2 and S4 of the second independent port module are turned on.

[0136] (4) When V a1 =+2U dc And V a2 When =0, the S of the shared port module a1 and S a5 When the circuit is turned on, S2 and S3 of the first independent port module are turned on, and S1 and S4 of the second independent port module are turned on.

[0137] (5) When V a1 =+U dc And V a2 =+2U dc At that time, the S of the shared port module a1 and S a5 When the circuit is turned on, S1 and S3 of the first independent port module are turned on, and S2 and S3 of the second independent port module are turned on.

[0138] (6) When V a1 =+U dc And V a2 =+2U dc At that time, the S of the shared port module a1 and S a5 When the circuit is turned on, S2 and S4 of the first independent port module are turned on, and S2 and S3 of the second independent port module are turned on.

[0139] (7) When V a1 =0 and V a2 =+2U dc At that time, the S of the shared port module a1 and S a5 When the circuit is turned on, S1 and S4 of the first independent port module are turned on, and S2 and S3 of the second independent port module are turned on.

[0140] (8) When V a1 =+U dc And V a2 When =0, the S of the shared port module a1 and S a5 When the circuit is turned on, S2 and S4 of the first independent port module are turned on, and S1 and S4 of the second independent port module are turned on.

[0141] (9) When V a1 =+U dc And V a2 When =0, the S of the shared port module a1 and S a5 When the circuit is turned on, S1 and S3 of the first independent port module are turned on, and S2 and S3 of the second independent port module are turned on.

[0142] (10) When V a1 =+U dc And V a2 When =0, the S of the shared port module a2 and S a5 When the circuit is turned on, S2 and S3 of the first independent port module are turned on, and S1 and S3 of the second independent port module are turned on.

[0143] (11) When V a1 =+U dc And V a2 When =0, the S of the shared port module a2 and S a5 When the circuit is turned on, S2 and S3 of the first independent port module are turned on, and S2 and S4 of the second independent port module are turned on.

[0144] (12) When V a1 =+U dc And V a2 =+U dc At that time, the S of the shared port module a2 and S a5 When the circuit is open, S2 and S3 of the first independent port module are open, and S2 and S3 of the second independent port module are open.

[0145] (13) When V a1 =+U dc And V a2 =+U dc At that time, the S of the shared port module a1 and S a5 When the circuit is open, S2 and S4 of the first independent port module are open, and S2 and S4 of the second independent port module are open.

[0146] (14) When V a1 =+Udc and V a2 =+U dc At that time, the S of the shared port module a1 and S a5 When the circuit is turned on, S1 and S3 of the first independent port module are turned on, and S2 and S4 of the second independent port module are turned on.

[0147] (15) When V a1 =+Udc And V a2 =+U dc At that time, the S of the shared port module a1 and S a5 When the circuit is turned on, S2 and S4 of the first independent port module are turned on, and S1 and S3 of the second independent port module are turned on.

[0148] (16) When V a1 =+U dc And V a2 =+U dc At that time, the S of the shared port module a1 and S a5 When the circuit is turned on, S1 and S3 of the first independent port module are turned on, and S1 and S3 of the second independent port module are turned on.

[0149] For example, when V a1 =0 and V a2 When = 0, the conduction combinations corresponding to zero level can include the following:

[0150] (1) S of the shared port module a2 and S a5 When the circuit is open, S2 and S4 of the first independent port module are open, and S2 and S4 of the second independent port module are open.

[0151] (2) S of the shared port module a2 and S a5 When the circuit is turned on, S2 and S4 of the first independent port module are turned on, and S1 and S3 of the second independent port module are turned on.

[0152] (3) S of the shared port module a2 and S a5 When the circuit is turned on, S1 and S3 of the first independent port module are turned on, and S2 and S4 of the second independent port module are turned on.

[0153] (4) S of the shared port module a2 and S a5 When the circuit is turned on, S1 and S3 of the first independent port module are turned on, and S1 and S3 of the second independent port module are turned on.

[0154] (5) S of the shared port module a3 and S a6 When the circuit is open, S2 and S4 of the first independent port module are open, and S2 and S4 of the second independent port module are open.

[0155] (6) S of the shared port module a3 and S a6 When the circuit is turned on, S2 and S4 of the first independent port module are turned on, and S1 and S3 of the second independent port module are turned on.

[0156] (7) S of the shared port module a3 and S a6 When the circuit is turned on, S1 and S3 of the first independent port module are turned on, and S2 and S4 of the second independent port module are turned on.

[0157] (8) S of the shared port module a3 and S a6 When the circuit is turned on, S1 and S3 of the first independent port module are turned on, and S1 and S3 of the second independent port module are turned on.

[0158] For the negative level state, the switching logic is the opposite of the corresponding positive level state, and V can be formed through the corresponding inverted switching logic. a1 and V a2 The negative output level. This embodiment will not repeat the list of each negative level combination. As can be seen from the above positive, zero, and negative level states, the same output level may correspond to multiple selectable switch combinations, thus enabling the shared port module and two independent port modules to cooperate to form the required multi-level output.

[0159] In one exemplary embodiment, such as Figure 6 As shown, the three-phase branch includes phase a branch, phase b branch and phase c branch, which are respectively connected to phase A, phase B and phase C of the AC bus.

[0160] For example, Figure 6 It shows Figure 5 The diagram illustrates the expansion relationship from a single-phase topology to a three-phase structure. For any phase x, x can be a, b, or c, and the first to sixth power devices in the corresponding phase branch can be represented as S, respectively. x1 S x2 S x3 S x4 S x5 and S x6 And form the corresponding shared port output node V. comx The two independent port modules respectively form the corresponding first port output V. x1 Second port output V x2 . Figure 6 In the diagram, 'a' corresponds to the output 'V'. a1 and V a2 b corresponds to the output V b1 and V b2 c corresponds to the output V c1 and V c2 Each phase independent port module's output node is connected to the corresponding phase line of the charging station's AC bus via a corresponding filter inductor L.

[0161] Understandable Figure 5Taking phase a branch as an example, the specific connection relationship between the shared port module and the two independent port modules is explained; Figure 6 The circuit structure, module connection relationship, and switching operation logic of the b-phase branch and c-phase branch are the same as those of the a-phase branch. The shared voltage formation method and the combination of positive, zero, and negative levels of the two independent ports described above for the a-phase branch can be applied to the b-phase branch and c-phase branch respectively according to the same principle.

[0162] In this way, by setting up the corresponding a-phase branch, b-phase branch and c-phase branch, and connecting the three-phase branches to the A-phase, B-phase and C-phase of the AC bus of the charging station respectively, the voltage transformation structure of the single-phase port can be extended to the three-phase AC system, so that each phase can form the required output voltage by the corresponding shared port branch and two independent port modules.

[0163] It should be understood that although the steps in the flowcharts of the embodiments described above are shown sequentially according to the arrows, these steps are not necessarily executed in the order indicated by the arrows. Unless explicitly stated herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least some steps in the flowcharts of the embodiments described above may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but can be executed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed alternately or in turn with other steps or at least some of the steps or stages in other steps. It is understood that the steps in different embodiments can be freely combined as needed, and all non-contradictory solutions formed by such combinations are within the scope of protection of this application.

[0164] Based on the same inventive concept, this application also provides an operating apparatus for a port-sharing flexible capacity expansion device for charging stations, which implements the operating method of the aforementioned port-sharing flexible capacity expansion device for charging stations. The solution provided by this apparatus is similar to the implementation described in the above method. Therefore, the specific limitations of the one or more operating apparatus embodiments for port-sharing flexible capacity expansion devices for charging stations provided below can be found in the limitations of the operating method for port-sharing flexible capacity expansion devices for charging stations described above, and will not be repeated here.

[0165] In one exemplary embodiment, such as Figure 7As shown, an operating device 700 for a port-sharing flexible capacity expansion device for charging stations is provided. A controller is applied to the port-sharing flexible capacity expansion device. The port-sharing flexible capacity expansion device further includes a shared port module, a first independent port module, and a second independent port module. The controller is electrically connected to the shared port module, the first independent port module, and the second independent port module. The shared port module includes a positive DC bus, a negative DC bus, and a first DC capacitor and a second DC capacitor connected in series between the positive DC bus and the negative DC bus. The operating device 700 for the port-sharing flexible capacity expansion device for charging stations includes: an acquisition module 701, an equivalent module 702, a comparison module 703, a first output module 704, and a second output module 705, wherein:

[0166] The acquisition module 701 is used to acquire the initial modulation signals of the first independent port module and the second independent port module respectively;

[0167] The equivalent module 702 is used to determine the equivalent modulation signal based on the initial modulation signal and the preset vector synthesis strategy;

[0168] The comparison module 703 is used to determine the target switch combination of the shared port module based on the comparison result of the amplitude of the equivalent modulation signal with the preset positive voltage threshold and negative voltage threshold. The preset positive voltage threshold and negative voltage threshold are determined by the rated voltage of the first DC capacitor or the second DC capacitor and a preset ratio.

[0169] The first output module 704 is used to control the on or off of each power device in the shared port module according to the target switch combination, so as to obtain the first output voltage of the shared port module.

[0170] The second output module 705 is used to determine the second output voltage of the first independent port module and the second independent port module respectively based on the initial modulation signal and the first output voltage.

[0171] In one embodiment, the acquisition module 701 is further configured to:

[0172] Obtain the amplitude and phase of the initial modulation signal of the first independent port module, and the amplitude and phase of the initial modulation signal of the second independent port module;

[0173] Based on the initial modulation signal and the preset vector synthesis strategy, the equivalent modulation signal is determined, including:

[0174] The amplitude and phase of the initial modulation signals of the first independent port module and the second independent port module are vector synthesized to obtain the amplitude and phase of the equivalent modulation signal.

[0175] In one embodiment, the negative terminal of the first DC capacitor and the positive terminal of the second DC capacitor are connected to a reference ground; the shared port module further includes a three-phase branch, each phase of which includes a first power device, a second power device, a third power device, and a fourth power device of the shared port module connected in series between the positive DC bus and the negative DC bus, and a bidirectional switching branch formed by a fifth power device and a sixth power device of the shared port module connected in series; the comparator module 703 is further configured to:

[0176] When the amplitude of the equivalent modulation signal is greater than the preset positive voltage threshold, the first power device and the fifth power device of the control shared port module are turned on.

[0177] When the amplitude of the equivalent modulation signal is less than the preset negative voltage threshold, the fourth and sixth power devices of the control shared port module are turned on.

[0178] When the amplitude of the equivalent modulation signal is not greater than a preset positive voltage threshold and not less than a preset negative voltage threshold, the second and fifth power devices of the shared port module are turned on, or the third and sixth power devices of the shared port module are turned on.

[0179] In one embodiment, the second output module 705 is further configured to:

[0180] The first output voltage is subtracted from the initial modulation signal of the first independent port module and the initial modulation signal of the second independent port module, respectively, to obtain the second output voltage of the first independent port module and the second independent port module.

[0181] In one embodiment, the first output module 704 is further configured to:

[0182] Generate the corresponding drive signal based on the target switch combination;

[0183] The drive signal controls the corresponding power device in the shared port module to turn on or off, so that the shared port module outputs a level corresponding to the target switch combination, thus obtaining the first output voltage.

[0184] The various modules in the operating device of the aforementioned port-sharing flexible capacity expansion device for charging stations can be implemented entirely or partially through software, hardware, or a combination thereof. These modules can be embedded in or independent of the processor in a computer device in hardware form, or stored in the memory of a computer device in software form, so that the processor can call and execute the operations corresponding to each module.

[0185] In one exemplary embodiment, an electronic device is provided, including a memory and a processor, wherein the memory stores a program, and the processor executes the program to implement the steps in the above-described method embodiments.

[0186] In one embodiment, a readable storage medium is provided on which a program is stored, which, when executed by a processor, implements the steps in the above method embodiments.

[0187] In one embodiment, a program product is provided, including a program that, when executed by a processor, implements the steps in the above method embodiments.

[0188] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, databases, or other media used in the embodiments provided in this application can include at least one of non-volatile memory and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM can take many forms, such as Static Random Access Memory (SRAM) or Dynamic Random Access Memory (DRAM). The databases involved in the embodiments provided in this application may include at least one type of relational database and non-relational database. Non-relational databases may include, but are not limited to, blockchain-based distributed databases. The processors involved in the embodiments provided in this application may be general-purpose processors, central processing units, graphics processing units, digital signal processors, programmable logic devices, quantum computing-based data processing logic devices, artificial intelligence (AI) processors, etc., and are not limited to these.

[0189] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this application.

[0190] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.

Claims

1. An operation method for a port-sharing flexible capacity expansion device for charging stations, characterized in that, A controller is applied to a port-sharing flexible capacity expansion device, the port-sharing flexible capacity expansion device further comprising a shared port module, a first independent port module, and a second independent port module. The controller is electrically connected to the shared port module, the first independent port module, and the second independent port module, respectively. The shared port module includes a positive DC bus, a negative DC bus, and a first DC capacitor and a second DC capacitor connected in series between the positive DC bus and the negative DC bus. The method includes: The initial modulation signals of the first independent port module and the second independent port module are acquired respectively; Based on the initial modulation signal and the preset vector synthesis strategy, the equivalent modulation signal is determined; Based on the comparison results between the amplitude of the equivalent modulation signal and the preset positive voltage threshold and negative voltage threshold, the target switch combination of the shared port module is determined. The preset positive voltage threshold and negative voltage threshold are determined by the rated voltage of the first DC capacitor or the second DC capacitor and a preset ratio. The first output voltage of the shared port module is obtained by controlling the conduction or cutoff of each power device in the shared port module according to the target switch combination. Based on the initial modulation signal and the first output voltage, the second output voltage of each of the first independent port module and the second independent port module is determined.

2. The method according to claim 1, characterized in that, The step of acquiring the initial modulation signals of the first independent port module and the second independent port module respectively includes: Obtain the amplitude and phase of the initial modulation signal of the first independent port module, and the amplitude and phase of the initial modulation signal of the second independent port module; The step of determining the equivalent modulation signal based on the initial modulation signal and a preset vector synthesis strategy includes: The amplitude and phase of the initial modulation signals of the first independent port module and the second independent port module are vector synthesized to obtain the amplitude and phase of the equivalent modulation signal.

3. The method according to claim 1, characterized in that, The negative terminal of the first DC capacitor and the positive terminal of the second DC capacitor are connected to a reference ground; the shared port module further includes a three-phase branch, each phase of which includes a first power device, a second power device, a third power device, and a fourth power device of the shared port module connected in series between the positive DC bus and the negative DC bus, and a bidirectional switch branch formed by the fifth and sixth power devices of the shared port module connected in series; determining the target switch combination of the shared port module based on the comparison result of the amplitude of the equivalent modulation signal with preset positive and negative voltage thresholds includes: When the amplitude of the equivalent modulation signal is greater than a preset positive voltage threshold, the first power device and the fifth power device of the shared port module are turned on. When the amplitude of the equivalent modulation signal is less than a preset negative voltage threshold, the fourth and sixth power devices of the shared port module are turned on. When the amplitude of the equivalent modulation signal is not greater than a preset positive voltage threshold and not less than a preset negative voltage threshold, the second and fifth power devices of the shared port module are turned on, or the third and sixth power devices of the shared port module are turned on.

4. The method according to claim 1, characterized in that, Determining the second output voltage of each of the first independent port module and the second independent port module based on the initial modulation signal and the first output voltage includes: The first output voltage is subtracted from the initial modulation signal of the first independent port module and the initial modulation signal of the second independent port module, respectively, to obtain the second output voltage of the first independent port module and the second independent port module.

5. The method according to claim 1, characterized in that, The step of controlling the on / off state of each power device in the shared port module according to the target switch combination to obtain the first output voltage of the shared port module includes: Generate a corresponding drive signal based on the target switch combination; The driving signal controls the corresponding power device in the shared port module to turn on or off, so that the shared port module outputs a level corresponding to the target switch combination, thereby obtaining a first output voltage.

6. A port-sharing flexible capacity expansion device for charging stations, characterized in that, The port-sharing flexible capacity expansion device includes a shared port module, a first independent port module, a second independent port module, a filter inductor, and a controller. The shared port module includes a positive DC bus, a negative DC bus, and a first DC capacitor and a second DC capacitor connected in series between the positive DC bus and the negative DC bus. The negative terminal of the first DC capacitor and the positive terminal of the second DC capacitor are connected to a reference ground. The shared port module also includes a three-phase branch. Each phase of the three-phase branch includes a first power device, a second power device, a third power device, and a fourth power device of the shared port module connected in series between the positive DC bus and the negative DC bus, and a bidirectional switch branch formed by the fifth power device and the sixth power device of the shared port module connected in series. The first independent port module and the second independent port module each include a single-phase full-bridge circuit composed of four power devices; The connection nodes of the fifth power device and the sixth power device are respectively connected to the connection nodes of the seventh power device and the eighth power device of the single-phase full-bridge circuit in the first independent port module and the second independent port module, and the connection nodes of the ninth power device and the tenth power device of the single-phase full-bridge circuit in the first independent port module and the second independent port module are respectively connected to the AC bus of the charging station through the filter inductor. The shared port module is used to provide multi-level voltage to the first independent port module and the second independent port module through the bidirectional switch branch; The controller is electrically connected to the shared port module, the first independent port module, and the second independent port module, respectively, and the controller is used to implement the steps of the method according to any one of claims 1 to 5 when executing the program.

7. The port-sharing flexible capacity expansion device according to claim 6, characterized in that, The single-phase full-bridge circuit also includes a DC capacitor. The collectors of the seventh power device and the ninth power device are respectively connected to the positive terminal of the DC capacitor, and the emitters of the eighth power device and the tenth power device are respectively connected to the negative terminal of the DC capacitor.

8. The port-sharing flexible capacity expansion device according to claim 6, characterized in that, The collector of the first power device of the shared port module is connected to the positive DC bus, the emitter of the first power device is connected to the collector of the second power device, the emitter of the second power device is connected to the collector of the third power device, the emitter of the third power device is connected to the collector of the fourth power device, and the emitter of the fourth power device is connected to the negative DC bus.

9. The port-sharing flexible capacity expansion device according to claim 6, characterized in that, In the bidirectional switch branch, the collector of the fifth power device is connected to the connection node between the first power device and the second power device, the emitter of the fifth power device is connected to the collector of the sixth power device, and the emitter of the sixth power device is connected to the connection node between the third power device and the fourth power device.

10. The port-sharing flexible capacity expansion device according to claim 6, characterized in that, The three-phase branch includes phase a, phase b, and phase c, which are respectively connected to phase A, phase B, and phase C of the AC bus.

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