Charging station power allocation system and method, controller and charging station

Abstract

The invention relates to a charging station power allocation system and method, a controller and a charging station, and relates to the technical field of charging stations. The charging station power allocation system comprises a sampling module and an allocation module. The sampling module is used for sampling a first voltage value of a primary side of a transformer and a second voltage value of a secondary side of the transformer in the charging station. And the allocation module is connected with the secondary side of the transformer and the sampling module and is used for adjusting the power flow direction of the secondary side of the transformer according to the first voltage value and the second voltage value. A sampling module samples a first voltage value of a primary side of a transformer in a charging station and a second voltage value of a secondary side of the transformer, and a distribution module can analyze the power supply capability of a current power grid through the first voltage value and the second voltage value. Therefore, the secondary side power flow direction of the transformer can be adjusted more accurately according to the real-time power supply capability of the power grid.

Description

Technical Field

[0001] The present application relates to the technical field of charging stations, and in particular, to a charging station power allocation system, method, controller, and charging station. Background Art

[0002] A charging station is an energy conversion device that obtains energy from the power grid to achieve charge and discharge control of electric vehicles. With the rapid development of the electric vehicle industry, the number of electric vehicles is increasing continuously. As an important supporting facility for electric vehicles, charging stations are being built on a large scale. When a charging station is expanded, it may encounter the problem of low power supply system capacity, which cannot meet the high-power charging demand and easily leads to overloading of the power grid.

[0003] Currently, in order to avoid overloading of the power grid, it is usually necessary to reasonably allocate the power of the charging station. For example, by presetting the standard voltage of the charging station and monitoring the current voltage in real time, when the current voltage drops, the power flow direction of the charging station is adjusted by starting energy storage inversion, so as to compensate for the dropped voltage, so that both the charging demand of the charging station can be met and the power grid will not be overloaded.

[0004] However, in the process of identifying the depth and slope of voltage drop, there may be blind spots in the identification of different voltage drop speeds, and it is impossible to accurately identify frequent voltage drops, resulting in inaccurate power allocation of the charging station. Summary of the Invention

[0005] An embodiment of the present application provides a charging station power allocation system to accurately allocate the power of the charging station to at least partially solve the above technical problems.

[0006] To achieve the above object, according to the first aspect of the present application, there is provided a charging station power allocation system, including: A sampling module for sampling a first voltage value of the primary side of a transformer in the charging station and a second voltage value of the secondary side of the transformer; An allocation module connected to the secondary side of the transformer and the sampling module for adjusting the power flow direction of the secondary side of the transformer according to the first voltage value and the second voltage value.

[0007] Optionally, the allocation module includes an energy storage commutation sub-module and a control sub-module; The control sub-module is connected to the sampling module for generating a commutation control signal according to the first voltage value and the second voltage value; The energy storage commutation sub-module is connected to the control sub-module and the secondary side of the transformer for adjusting the power flow direction of the secondary side of the transformer according to the commutation control signal.

[0008] Optionally, the energy storage commutation sub-module includes an AC-DC power converter and an energy storage battery; The AC-DC power converter includes a first side connected to the secondary side of the transformer, a second side connected to the energy storage battery, and a control terminal connected to the control sub-module, and is configured to adjust the conduction direction according to the commutation control signal; The energy storage battery is connected to the AC-DC power converter and is configured to charge or discharge according to the conduction direction of the AC-DC power converter.

[0009] Optionally, the energy storage commutation sub-module further includes a DC power converter; The DC power converter includes a first side connected to the energy storage battery and the AC-DC power converter and a second side connected to the charging load, and is configured to convert the power provided by the energy storage battery or the AC-DC power converter to supply power to the charging load.

[0010] Optionally, the sampling module further includes a current sampler connected in series to the secondary side of the transformer, and is configured to sample the operating current signal of the secondary side of the transformer.

[0011] Optionally, the control sub-module is configured to obtain a voltage deviation value between the primary side and the secondary side of the transformer according to the first voltage value and the second voltage value, and generate the commutation control signal according to the voltage deviation value and the operating current signal.

[0012] According to a second aspect of the present application, there is provided a method for power allocation of a charging station, which is applied to the above-mentioned power allocation system of the charging station, and includes: Obtaining a first voltage value of the primary side of a transformer in the charging station and a second voltage value of the secondary side of the transformer through the sampling module; Adjusting the power flow direction of the secondary side of the transformer according to the first voltage value and the second voltage value through the allocation module.

[0013] Optionally, the allocation module includes an AC-DC power converter, and the adjusting the power flow direction of the secondary side of the transformer according to the first voltage value and the second voltage value through the allocation module includes: Obtaining a voltage deviation value between the primary side and the secondary side of the transformer according to the first voltage value and the second voltage value; Adjusting the conduction direction of the AC-DC power converter according to the voltage deviation value to adjust the power flow direction of the secondary side of the transformer.

[0014] Optionally, the adjusting the conduction direction of the AC-DC power converter according to the voltage deviation value includes: Sample the current on the secondary side of the transformer to obtain an operating current signal; Generate a commutation control signal according to the voltage deviation value and the operating current signal, so that the AC-DC power converter adjusts the conduction direction according to the commutation control signal.

[0015] Optionally, the commutation control signal includes a first adjustment signal and a second adjustment signal; the allocation module includes an energy storage battery; generating the commutation control signal according to the voltage deviation value and the operating current signal includes: When the voltage deviation value is greater than or equal to zero, obtain the charging demand current of the energy storage battery, and generate the first adjustment signal according to the charging demand current and the operating current signal to control the AC-DC power converter to conduct in a first direction; When the voltage deviation value is less than zero, obtain the discharge demand current of the energy storage battery, generate a commutation adjustment amount according to the voltage deviation value, and generate the second adjustment signal according to the commutation adjustment amount, the discharge demand current and the operating current signal to control the AC-DC power converter to conduct in a second direction; Wherein, the first direction is the direction from the first side to the second side of the AC-DC power converter, and the second direction is the direction from the second side to the first side of the AC-DC power converter.

[0016] Optionally, generating the commutation adjustment amount according to the voltage deviation value includes: Perform proportional-integral processing on the voltage deviation value to obtain a demand adjustment amount; Determine the limit range according to the discharge demand current; Limit the demand adjustment amount according to the limit range to obtain the commutation adjustment amount.

[0017] Optionally, generating the second adjustment signal according to the commutation adjustment amount, the discharge demand current and the operating current signal includes: Generate a demand control signal according to the commutation adjustment amount and the discharge demand current, and perform phase-locking processing on the demand control signal to make the phase of the demand control signal consistent with the phase of the primary side voltage of the transformer; Calculate a current difference according to the demand control signal and the operating current signal; Perform proportional-integral processing on the current difference to obtain the second adjustment signal.

[0018] Optionally, the method further includes: Obtain the remaining power of the energy storage battery, and if the remaining power is lower than a preset value, output an alarm message.

[0019] According to a third aspect of the present application, there is provided a controller on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are implemented.

[0020] According to a fourth aspect of the present application, a charging station includes the above-mentioned charging station power distribution system.

[0021] In summary, in the charging station power distribution system according to the embodiments of the present application, the sampling module samples the first voltage value of the primary side of the transformer and the second voltage value of the secondary side of the transformer in the charging station. The distribution module can analyze the power supply capacity of the current power grid through the first voltage value and the second voltage value, and can achieve the effect of more accurately adjusting the power flow direction of the secondary side of the transformer according to the real-time power supply capacity of the power grid.

[0022] Other features and advantages of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0023] In order to more fully understand the present application and its beneficial effects, the following will be described in conjunction with the drawings, where the same reference numerals in the following description represent the same parts.

[0024] Figure 1 is a schematic diagram of the charging station power distribution system provided in an exemplary embodiment of the present disclosure; Figure 2 is a schematic diagram of an application scenario of the charging station power distribution system provided in an exemplary embodiment of the present disclosure; Figure 3 is a circuit connection diagram of the charging station power distribution system provided in an exemplary embodiment of the present disclosure; Figure 4 is a schematic diagram of the power flow direction of the secondary side of the transformer provided in an exemplary embodiment of the present disclosure; Figure 5 is a flowchart of the charging station power distribution method provided in an exemplary embodiment of the present disclosure; Figure 6 is a schematic diagram of a control scenario of the charging station power distribution method provided in an exemplary embodiment of the present disclosure.

[0025] Description of the reference numerals: 1. Sampling module; 2. Blending module; 21. Energy storage commutation sub-module; 211. AC-DC power converter; 212. Energy storage battery; 213. DC power converter; 22. Control sub-module. Specific embodiments

[0026] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present application.

[0027] According to the first aspect of the present application, with reference to Figures 1 to 4 , the present disclosure provides a charging station power distribution system, including a sampling module 1 and a blending module 2. Among them, the sampling module 1 is used to sample the first voltage value of the primary side of the transformer and the second voltage value of the secondary side of the transformer in the charging station. The blending module 2 is connected to the secondary side of the transformer and the sampling module 1, and is used to adjust the power flow direction of the secondary side of the transformer according to the first voltage value and the second voltage value.

[0028] Among them, when the power supply capacity of the power grid is insufficient, the equivalent impedance of the power grid (including line impedance and the impedance of the transformer itself) is relatively large, resulting in an obvious voltage drop when the current flows through. In order to maintain the stability of the secondary side voltage of the transformer, the power grid will increase the primary side voltage of the transformer by adjusting the transformer tap or other means to compensate for the loss caused by the voltage drop. Therefore, when the power supply capacity of the power grid is insufficient and it is necessary to increase the primary side voltage of the transformer to meet the load demand, the primary side voltage of the transformer will be greater than its secondary side voltage. When the power supply capacity of the power grid is sufficient, the equivalent impedance of the power grid is relatively small, and there will be no obvious voltage drop when the current flows through. The power grid not only does not need to increase the primary side voltage of the transformer to compensate for the loss, but can also optimize the power transmission efficiency by reducing the primary side voltage. Therefore, when the power supply capacity of the power grid is sufficient and there is no need to increase or decrease the primary side voltage of the transformer, the primary side voltage of the transformer will be less than or equal to its secondary side voltage.

[0029] Therefore, when the first voltage value is greater than the second voltage value, it indicates that the power supply capacity of the power grid is weak at this time. When the first voltage value is less than or equal to the second voltage value, it indicates that the power supply capacity of the power grid is strong at this time. In this way, by comparing the first voltage value and the second voltage value, the power supply capacity of the power grid can be reflected, so as to more accurately adjust the power flow direction of the secondary side of the transformer.

[0030] Combined with Figure 2, for example, the primary side of the transformer in the charging station is connected to the power grid, and the secondary side of the transformer is connected to the distribution module 2, which is used to supply energy to the charging load. Taking the scenario of a vehicle 4S store as an example, to meet the charging needs of customer vehicles, multiple charging stations are usually set up to charge multiple charging loads respectively, and the charging load can be a vehicle. Each charging station converts energy through a transformer T1. The primary sides of the transformers T1 are all connected to the power grid, and their secondary sides are powered to the charging load after power adjustment by the power distribution system of their respective substations, thereby realizing the distribution of grid electric energy.

[0031] In the above embodiment, the sampling module 1 samples the first voltage value of the primary side and the second voltage value of the secondary side of the transformer in the charging station. The distribution module 2 can analyze the current power supply capacity of the power grid through the first voltage value and the second voltage value, and can achieve the effect of more accurately adjusting the power flow direction of the secondary side of the transformer according to the real-time power supply capacity of the power grid.

[0032] Refer to Figure 3 , in some embodiments, the distribution module 2 includes an energy storage commutation sub-module 21 and a control sub-module 22. Among them, the control sub-module 22 is connected to the sampling module 1 and is used to generate a commutation control signal according to the first voltage value and the second voltage value. The energy storage commutation sub-module 21 is connected to the control sub-module 22 and the secondary side of the transformer, and is used to adjust the power flow direction of the secondary side of the transformer according to the commutation control signal.

[0033] In the above embodiment, the control sub-module 22 is connected to the sampling module 1, can obtain the first voltage value of the primary side and the second voltage value of the secondary side of the transformer, and generates a commutation control signal for quantifying the power supply capacity of the power grid according to the first voltage value and the second voltage value, so that the energy storage commutation sub-module 21 can make corresponding adjustments to the power flow direction of the secondary side of the transformer after receiving the commutation control signal sent by the control sub-module 22.

[0034] In some embodiments, the energy storage commutation sub-module 21 includes an AC-DC power converter 211 and an energy storage battery 212. The AC-DC power converter 211 includes a first side connected to the secondary side of the transformer, a second side connected to the energy storage battery 212, and a control end connected to the control sub-module 22, and is used to adjust the conduction direction according to the commutation control signal. The energy storage battery 212 is connected to the AC-DC power converter 211 and is used to charge or discharge according to the conduction direction of the AC-DC power converter 211.

[0035] , for example, the AC-DC power converter 211 is a bidirectional energy conversion device that can realize the bidirectional conversion of alternating current and direct current. The secondary side of the transformer is also connected to other loads. Continuing with the example of a vehicle 4S store, other loads can be office electricity or warehouse electricity, etc. Refer to Figure 4In (a) of [description], when the first voltage value is less than or equal to the second voltage value, it indicates that the power supply capacity of the power grid is relatively strong. At this time, while the secondary side of the transformer supplies alternating current to other loads, it also transmits the alternating current to the AC-DC power converter 211. The AC-DC power converter 211 operates in the rectification mode, converting the alternating current on the secondary side of the transformer into direct current to supply power to the charging load and charge the energy storage battery 212, so as to store the excess electric energy on the secondary side of the transformer. At this time, the power flow direction of the secondary side of the transformer is from the secondary side of the transformer to other loads and the AC-DC power converter 211, and then through the AC-DC power converter 211 to the energy storage battery 212 and the charging load.

[0036] Combined with Figure 4 In (b) of [description], when the first voltage value is greater than the second voltage value, it indicates that the power supply capacity of the power grid is weak. The AC-DC power converter 211 is in the inversion mode, supplying power to the charging load with the direct current discharged from the energy storage battery 212. At the same time, the AC-DC power converter 211 inverses the direct current output by the energy storage battery 212 into alternating current and supplements it to the secondary side of the transformer to supply power to other loads. At this time, the power flow direction of the secondary side of the transformer is from the energy storage battery 212 to the charging load, and at the same time, the output of the energy storage battery 212 is transmitted to the secondary side of the transformer through the AC-DC power converter 211, so as to supply power to other loads connected to the secondary side of the transformer.

[0037] In this way, when the power supply capacity of the power grid is relatively strong, the secondary side of the transformer can supply energy to the charging load and other loads and charge the energy storage battery 212. When the power supply capacity of the power grid is relatively weak, the energy storage battery 212 can supply energy to the charging load and other loads.

[0038] Referring to Figure 3 , in some embodiments, the energy storage commutation sub-module 21 further includes a DC power converter 213. The DC power converter 213 includes a first side connected to the energy storage battery 212 and the AC-DC power converter 211 and a second side connected to the charging load, and is used to convert the power provided by the energy storage battery 212 or the AC-DC power converter 211 to supply power to the charging load.

[0039] In the above embodiments, when the first voltage value is less than or equal to the second voltage value, the DC power converter 213 converts the power provided by the AC-DC power converter 211 to supply power to the charging load. When the first voltage value is greater than the second voltage value, the DC power converter 213 converts the power from the energy storage battery 212 to supply power to the charging load, ensuring the power supply stability of the charging load through the DC power converter 213, so that the charging load can be charged with a stable voltage.

[0040] In some embodiments, the sampling module 1 further includes a current sampler connected in series to the secondary side of the transformer, which is configured to sample the operating current signal of the secondary side of the transformer. The control sub-module 22 is configured to obtain the voltage deviation value between the primary side and the secondary side of the transformer according to the first voltage value and the second voltage value, and generate a commutation control signal according to the voltage deviation value and the operating current signal.

[0041] As an example, the current sampler can be a current transformer, which can convert the large current on the secondary side of the transformer into a small current signal in proportion for measurement.

[0042] Referring to Figure 5 , according to the second aspect of the present application, there is provided a method for power distribution of a charging station, which is applied to the above-mentioned power distribution system of the charging station, and includes steps S100-step S200, which will be introduced in detail below.

[0043] Step S100: Obtain the first voltage value of the primary side of the transformer in the charging station and the second voltage value of the secondary side of the transformer through the sampling module 1.

[0044] Step S200: Adjust the power flow direction of the secondary side of the transformer by the deployment module 2 according to the first voltage value and the second voltage value.

[0045] In the above embodiment, the sampling module 1 samples the first voltage value of the primary side of the transformer and the second voltage value of the secondary side in the charging station. The deployment module 2 can analyze the power supply capacity of the current power grid through the first voltage value and the second voltage value, and can achieve the effect of more accurately adjusting the power flow direction of the secondary side of the transformer according to the real-time power supply capacity of the power grid.

[0046] In some embodiments, the deployment module 2 includes an AC-DC power converter 211, and step S200 may include steps S210-step S220, which will be introduced in detail below.

[0047] Step S210: Obtain the voltage deviation value between the primary side and the secondary side of the transformer according to the first voltage value and the second voltage value.

[0048] As an example, the voltage deviation value may be the difference between the second voltage value and the first voltage value. When the voltage deviation value is greater than or equal to zero, the first voltage value is less than or equal to the second voltage value, indicating that the power supply capacity of the power grid is relatively strong. When the voltage deviation value is less than zero, the first voltage value is greater than the second voltage value, indicating that the power supply capacity of the power grid is relatively weak.

[0049] Step S220: Adjust the conduction direction of the AC-DC power converter 211 according to the voltage deviation value to adjust the power flow direction of the secondary side of the transformer.

[0050] As an example, the AC-DC power converter 211 can achieve bidirectional conversion between alternating current and direct current, and its conduction direction determines the power transfer direction. By controlling its conduction direction through the voltage deviation value, the flow direction of the secondary side power of the transformer can be flexibly controlled.

[0051] As an example, step S220 may include steps S221 - S222, which will be introduced in detail below.

[0052] Step S221: Sample the current on the secondary side of the transformer to obtain an operating current signal.

[0053] As an example, the current sampler is used to measure the current on the secondary side of the transformer during actual operation in real time to obtain an operating current signal, and the operating current signal reflects the operating state of the secondary side of the transformer.

[0054] Step S222: Generate a commutation control signal based on the voltage deviation value and the operating current signal, so that the AC-DC power converter 211 adjusts its conduction direction according to the commutation control signal.

[0055] As an example, the AC-DC power converter 211 can be a full-bridge rectifier circuit. The full-bridge rectifier circuit includes several power switch devices. The commutation control signal can be a Pulse-Width Modulation (PWM) signal. There can be multiple paths for the commutation control signal, and each path of the commutation control signal is used to control one power switch device in the AC-DC power converter 211. In the AC-DC power converter 211, by adjusting the duty cycle of the commutation control signal, the on and off times of the power switch devices in the AC-DC power converter 211 can be changed, thereby controlling the energization time of the primary side of the transformer inside the AC-DC power converter 211. For example, when the duty cycle of the commutation control signal increases, the on time of the power switch tube in the AC-DC power converter 211 extends, the energy stored in the primary side of the transformer inside the AC-DC power converter 211 increases, and the energy transferred to its secondary side also increases accordingly, causing the output voltage of the AC-DC power converter 211 to rise; conversely, when the duty cycle decreases, the output voltage of the AC-DC power converter 211 decreases. In addition, by adjusting the phase of the commutation control signal, the conduction timing of each power switch device in the AC-DC power converter 211 is controlled, so that the power switch devices in the AC-DC power converter 211 conduct or cut off in different combinations, thereby achieving the control of the conduction direction of the AC-DC power converter 211.

[0056] Thus, the conduction direction of the AC-DC power converter 211 can be determined by the voltage deviation value to determine the phase of the commutation control signal. The operating current signal is used as the feedback quantity of the AC-DC power converter 211, and the signal amplitude required to be output by the AC-DC power converter 211 can be determined to determine the duty cycle of the commutation control signal. Therefore, according to the voltage deviation value and the operating current signal, the commutation control signal can be obtained to adjust the conduction direction and the output voltage amplitude of the AC-DC power converter 211.

[0057] In some embodiments, the commutation control signal includes a first adjustment signal and a second adjustment signal, and the allocation module 2 includes a storage battery 212. Step S222 may include steps S2221-S2222, which will be introduced in detail below.

[0058] Step S2221: When the voltage deviation value is greater than or equal to zero, obtain the charging demand current of the storage battery 212, and generate a first adjustment signal according to the charging demand current and the operating current signal to control the AC-DC power converter 211 to conduct in a first direction.

[0059] As an example, when the voltage deviation value is greater than or equal to zero, it indicates that the power supply capacity of the power grid is relatively strong, and the power grid provides energy to charge the storage battery 212. Therefore, at this time, the charging demand current of the storage battery 212 is obtained. The charging demand current is used as the ideal output value that the AC-DC power converter 211 is expected to reach, and the operating current signal is used as the actual measured value. By performing proportional-integral operation on the charging demand current and the operating circuit signal, the first adjustment signal can be obtained. The first adjustment signal is used to control the AC-DC power converter 211 to conduct in a first direction from the first side to the second side of the AC-DC power converter 211 to realize the charging of the storage battery 212.

[0060] Step S2222: When the voltage deviation value is less than zero, obtain the discharge demand current of the storage battery 212, generate a commutation adjustment amount according to the voltage deviation value, and generate a second adjustment signal according to the commutation adjustment amount, the discharge demand current and the operating current signal to control the AC-DC power converter 211 to conduct in a second direction.

[0061] As an example, when the voltage deviation value is less than zero, it indicates that the power supply capacity of the power grid is relatively weak, and the power grid cannot provide enough energy, and part of the energy needs to be provided by the storage battery 212. Therefore, it is necessary to obtain the discharge demand current of the storage battery 212.

[0062] Among them, the first direction is the direction from the first side to the second side of the AC-DC power converter 211, and the second direction is the direction from the second side to the first side of the AC-DC power converter 211. The charging demand current and the discharge demand current can be obtained from the charge-discharge curve of the storage battery 212, and the charge-discharge curves of different types of storage batteries 212 may be different. CombinedFigure 6 where \(I_a\) represents the discharge demand current, and \(I_b\) represents the charging demand current; \(U_1\) represents the first voltage value, \(U_2\) represents the second voltage value, and \(I_1\) represents the operating current signal.

[0063] In some embodiments, generating the commutation adjustment amount according to the voltage deviation value may include steps S201 - S203, which will be introduced in detail below.

[0064] Step S201: Perform proportional-integral processing on the voltage deviation value to obtain the demand adjustment amount.

[0065] As an example, proportional-integral processing is a commonly used control algorithm, which can be executed by a PI (Proportional-Integral) controller. The PI controller performs proportional operation on the voltage deviation value to amplify or reduce the voltage deviation value, and at the same time performs integral operation to accumulate the change of the voltage deviation value over time, so as to obtain the demand adjustment amount, which reflects the adjustment amplitude that needs to be made according to the current voltage deviation value. The sign of the demand adjustment amount is the same as that of the voltage deviation value. When the voltage deviation value is greater than or equal to zero, the demand adjustment amount is also a value greater than or equal to zero; when the voltage deviation value is less than zero, the demand adjustment amount is also less than zero.

[0066] Step S202: Determine the limiting range according to the discharge demand current.

[0067] Step S203: Limit the demand adjustment amount according to the limiting range to obtain the commutation adjustment amount.

[0068] As an example, the limiting range can be expressed as \([-2\times I_a, 0]\). When the demand adjustment amount is less than \(-2\times I_a\), the commutation adjustment amount is \(-2\times I_a\); when the demand adjustment amount is greater than or equal to \(-2\times I_a\) and less than 0, the demand adjustment amount is used as the commutation adjustment amount. When the demand adjustment amount is greater than 0, the commutation adjustment amount is 0. In the case where the voltage deviation value is greater than zero, no commutation adjustment amount is output, and the first adjustment signal is directly generated by the charging demand current and the operating current signal.

[0069] In the above embodiments, the commutation adjustment amount is obtained by limiting the demand adjustment amount, which avoids damage to the energy storage battery 212 caused by the output of the AC-DC power converter 211 exceeding the rated voltage of the energy storage battery 212.

[0070] In some embodiments, generating the second adjustment signal according to the commutation adjustment amount, the discharge demand current, and the operating current signal may include steps S204 - S206, which will be introduced in detail below.

[0071] Step S204: Generate a demand control signal based on the commutation adjustment amount and the discharge demand current, and perform phase-locking processing on the demand control signal so that the phase of the demand control signal is consistent with the phase of the primary voltage of the transformer.

[0072] Step S205: Calculate the current difference based on the demand control signal and the operating current signal.

[0073] Step S206: Perform proportional-integral processing on the current difference to obtain a second adjustment signal.

[0074] In some embodiments, the charging station power allocation method further includes obtaining the remaining power of the energy storage battery 212, and if the remaining power is lower than a preset value, an alarm message is output.

[0075] The working process of the charging station power allocation method of the present disclosure is exemplarily described as follows: First, a commutation control signal with different duty cycles and phases is generated based on the voltage deviation value and the operating current signal. The commutation control signal can directly participate in the control of the conduction direction and output amplitude of the AC-DC power converter 211, without additional switch control, and there will be no problem of switch control delay. Then, by controlling the conduction direction and output amplitude of the AC-DC power converter 211, the adjustment of the secondary power flow direction of the transformer is realized. In addition, the voltage deviation value is obtained by comparing the first voltage value and the second voltage value, which is relatively simple, can achieve zero-time switching, is not affected by the speed of the transformer voltage drop, and there is no recognition blind area, so that the adjustment of the secondary power of the transformer can be realized more accurately and quickly.

[0076] According to the third aspect of the present application, a controller is provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of the above method are realized.

[0077] According to the fourth aspect of the present application, a charging station includes the above-mentioned charging station power allocation system.

[0078] In the description of the present application, the terms "first" and "second" are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more features. In the description of the present application, "a plurality" means two or more, unless otherwise specifically defined.

[0079] In the above embodiments, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0080] The embodiments, implementation manners and related technical features of the present application can be combined and replaced with each other without conflict.

[0081] The above are only the preferred embodiments of the present application, and do not impose any form of limitation on the present application. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application still fall within the scope of the technical solution of the present application.

Claims

1. A charging station power allocation system, characterized in that: include: A sampling module, used for sampling a first voltage value of a primary side of a transformer in a charging station and a second voltage value of a secondary side of the transformer; The adjustment module is connected to the secondary side of the transformer and the sampling module, and is used to adjust the power flow direction of the secondary side of the transformer according to the first voltage value and the second voltage value.

2. The charging station power allocation system according to claim 1, characterized in that: The deployment module includes an energy storage reversing submodule and a control submodule; The control submodule is connected to the sampling module and is used to generate a commutation control signal according to the first voltage value and the second voltage value; The energy storage commutation submodule is connected to the control submodule and the secondary side of the transformer, and is used to adjust the power flow direction of the secondary side of the transformer according to the commutation control signal.

3. The charging station power allocation system according to claim 2, characterized in that: The energy storage commutation submodule includes an AC / DC power converter and an energy storage battery; The AC-DC power converter comprises a first side connected to the secondary side of the transformer, a second side connected to the energy storage battery, and a control end connected to the control submodule, and is used to adjust the conduction direction according to the commutation control signal; The energy storage battery is connected to the AC-DC power converter and is used for charging or discharging according to the conduction direction of the AC-DC power converter.

4. The charging station power allocation system according to claim 3, characterized in that: The energy storage commutation submodule also includes a DC power converter; The DC power converter includes a first side connected to the energy storage battery and the AC / DC power converter and a second side connected to a charging load, and is used to convert power provided by the energy storage battery or the AC / DC power converter to supply power to the charging load.

5. The charging station power allocation system according to claim 2, characterized in that: The sampling module further includes a current sampler connected in series to the secondary side of the transformer, and is used to sample the operating current signal of the secondary side of the transformer.

6. The charging station power allocation system according to claim 5, characterized in that: The control submodule is used to obtain a voltage deviation value between the primary side of the transformer and the secondary side of the transformer according to the first voltage value and the second voltage value, and to generate the commutation control signal according to the voltage deviation value and the operating current signal.

7. A charging station power allocation method, characterized in that: The charging station power allocation system applied to any one of claims 1 to 6 comprises: Acquire a first voltage value of a primary side of a transformer in a charging station and a second voltage value of a secondary side of the transformer through the sampling module; The power flow direction of the secondary side of the transformer is adjusted according to the first voltage value and the second voltage value by the adjustment module.

8. The charging station power allocation method according to claim 7, characterized in that: The adjustment module includes an AC / DC power converter, and the adjustment module adjusts the power flow direction of the secondary side of the transformer according to the first voltage value and the second voltage value, including: Obtaining a voltage deviation value between a primary side and a secondary side of the transformer according to the first voltage value and the second voltage value; The conduction direction of the AC-DC power converter is adjusted according to the voltage deviation value to adjust the power flow direction of the secondary side of the transformer.

9. The charging station power allocation method according to claim 8, characterized in that: The step of adjusting the conduction direction of the AC / DC power converter according to the voltage deviation value comprises: Sampling the current on the secondary side of the transformer to obtain an operating current signal; A commutation control signal is generated according to the voltage deviation value and the operating current signal, so that the AC-DC power converter adjusts the conduction direction according to the commutation control signal.

10. The charging station power allocation method according to claim 9, characterized in that: The commutation control signal includes a first adjustment signal and a second adjustment signal; the adjustment module includes an energy storage battery; and the commutation control signal is generated according to the voltage deviation value and the operating current signal, including: When the voltage deviation value is greater than or equal to zero, obtaining the charging demand current of the energy storage battery, and generating the first regulating signal according to the charging demand current and the operating current signal to control the AC-DC power converter to conduct in a first direction; When the voltage deviation value is less than zero, the discharge demand current of the energy storage battery is obtained, a commutation adjustment amount is generated according to the voltage deviation value, and the second adjustment signal is generated according to the commutation adjustment amount, the discharge demand current and the operating current signal to control the AC-DC power converter to conduct in a second direction; The first direction is a direction from a first side to a second side of the AC-DC power converter, and the second direction is a direction from the second side to the first side of the AC-DC power converter.

11. The charging station power allocation method according to claim 10, characterized in that: Generating a commutation adjustment amount according to the voltage deviation value includes: Performing proportional integration processing on the voltage deviation value to obtain a demand adjustment amount; Determining a limiting range according to the discharge demand current; According to the limiting range, the demand adjustment amount is limited to obtain the switching adjustment amount.

12. The charging station power allocation method according to claim 10, characterized in that: The generating a second adjustment signal according to the commutation adjustment amount, the discharge demand current and the operating current signal comprises: Generate a demand control signal according to the commutation adjustment amount and the discharge demand current, and perform phase-locking processing on the demand control signal so that the phase of the demand control signal is consistent with the phase of the primary voltage of the transformer; Calculating a current difference according to the demand control signal and the operating current signal; Proportional integration processing is performed on the current difference to obtain the second adjustment signal.

13. The charging station power allocation method according to claim 10, characterized in that: The method further comprises: The remaining power of the energy storage battery is obtained, and if the remaining power is lower than a preset value, an alarm message is output.

14. A controller having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 7 to 13 are implemented.

15. A charging station, characterized in that: It comprises a charging station power allocation system as described in any one of claims 1 to 6.

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