Power Quality Support Device Applied to Charging Pile and Charging Pile

Abstract

The present application relates to a power quality support device and a charging pile applied to a charging pile, which overcomes the shortcomings of the prior art. By performing harmonic detection, three-phase current imbalance detection, and output voltage fluctuation detection on the power supply module in real time, the power quality problems at the load end of the power supply module are discovered. After comprehensively considering various power quality problems, power quality control instructions are generated in combination with power quality control strategies and transmitted to each power quality control module for corresponding control, so as to dynamically solve power quality problems such as harmonic pollution, three-phase imbalance, and output voltage fluctuation of the charging pile, effectively ensuring the operation efficiency and charging effect of the charging pile. At the same time, the entire power quality support device adopts a modular design, and each functional module operates independently and can be replaced independently, improving the convenience of maintenance and upgrade and enhancing the flexibility of the device. By introducing redundant modules, it helps to ensure the continuous operation of the system and minimize the impact on charging services to the greatest extent.

Description

Technical Field

[0001] The present application relates to the technical field of power regulation of charging piles, and in particular to a power quality support device and a charging pile applied to a charging pile. Background Art

[0002] In the field of electric vehicles, charging piles are the core equipment of electric vehicle charging facilities and are becoming more and more intelligent. Existing charging piles can realize unidirectional or bidirectional power transmission. Among them, bidirectional charging piles can charge electric vehicles and feed back the power of electric vehicles to charging piles and power grids, thereby realizing flexible allocation of power. In the actual application of bidirectional charging piles, the power grid conditions are particularly complex and the power grid load is prone to drastic fluctuations. Therefore, in terms of power quality support, existing bidirectional charging piles still face a series of problems, especially harmonic pollution and three-phase imbalance.

[0003] The three-phase imbalance problem of bidirectional charging piles is mainly caused by the imbalance of charging load. Most existing technologies use static control methods to partially compensate, but when the grid load changes, the three-phase imbalance problem will reappear and persist, which has a negative impact on the operating efficiency of the charging piles and the charging effect of the car, and is not conducive to promotion and application. Summary of the invention

[0004] Based on this, the present application provides a power quality support device and a charging pile for use in a charging pile. By designing various functional modules, the power quality problems of the charging pile, such as harmonic pollution, three-phase imbalance, and output voltage fluctuation, are dynamically solved, thereby effectively ensuring the operating efficiency and charging effect of the charging pile.

[0005] On the one hand, the present application provides a power quality support device applied to a charging pile, including a power supply module, a control module, and a harmonic control module, a three-phase regulation module, and a voltage regulation module electrically connected to the control module.

[0006] The three-phase connection end of the power module is used to connect to the external power grid, and the load end of the power module is used to connect to the load device. The power module obtains electrical energy from the external power grid or the load device, and transmits the converted electrical energy to the load device or the external power grid.

[0007] The harmonic control module is used to detect the real-time harmonic parameters of the load end of the power module, transmit them to the control module, and receive the harmonic control instructions sent by the control module to perform harmonic control.

[0008] The three-phase regulation module is used to detect the real-time parameters of the three-phase current at the three-phase connection end of the power module, transmit them to the control module, and receive the three-phase regulation instructions sent by the control module to perform three-phase current imbalance management.

[0009] The voltage regulation module is used to detect the real-time parameters of the output voltage at the load end of the power supply module, transmit them to the control module, and receive the voltage fluctuation control instruction sent by the control module to perform voltage fluctuation control.

[0010] The control module receives the real-time harmonic parameters, the real-time three-phase current parameters, and the real-time output voltage parameters, generates a power quality control instruction in combination with the power quality control strategy, and sends the power quality control instruction to the corresponding module to control and execute the corresponding power quality control. Among them, the power quality control instruction includes the harmonic control instruction, the three-phase regulation instruction, and the voltage fluctuation control instruction.

[0011] In one embodiment, the power quality control strategy includes a collaborative control strategy. The collaborative control strategy is as follows: when the real-time harmonic parameters exceed the first preset harmonic threshold, the real-time three-phase current parameters exceed the first preset current threshold, and the real-time output voltage parameters exceed the first preset voltage threshold, the optimal values of each function variable are determined based on the minimization of a pre-constructed comprehensive control objective function, and the corresponding harmonic control instruction, three-phase regulation instruction, and voltage fluctuation control instruction are generated according to the optimal values of each function variable; the minimization method of the comprehensive control objective function is: , where is the active power of the th harmonic, is the reactive power of the th harmonic, is the vector difference of the three-phase unbalanced current, is the fluctuation amplitude of the output voltage, is the harmonic control weight, is the three-phase unbalance control weight, is the voltage control weight.

[0012] The constraint conditions of the comprehensive control objective function include: voltage fluctuation constraint condition: , is the maximum allowable voltage fluctuation limit of the preset output voltage; three-phase unbalance constraint condition: , is the maximum vector limit of the preset three-phase unbalanced current; harmonic power constraint condition: , is the maximum allowable active power limit of the preset th harmonic, is the maximum allowable reactive power limit of the preset th harmonic.

[0013] The optimal values of the function variables include: the Active power of the subharmonic and reactive power optimal values, three-phase unbalanced current vector difference optimal values, and the fluctuation amplitude of the output voltage optimal values.

[0014] In one embodiment, the generating the corresponding power quality governance instruction according to the optimal values of the respective function variables includes: according to the active power of the subharmonic and reactive power optimal values and the difference between the real-time harmonic power at the load end of the power supply module to determine the compensation current, generating the harmonic governance instruction according to the compensation current, the real-time harmonic power is determined by the harmonic real-time parameters; according to the three-phase unbalanced current vector difference optimal values and the difference between the real-time three-phase current parameters of the power supply module to determine the three-phase current adjustment amount, generating the three-phase adjustment instruction according to the three-phase current adjustment amount; according to the fluctuation amplitude of the output voltage optimal values and the sum of the real-time output voltage parameters of the power supply module to determine the voltage adjustment amount, generating the voltage fluctuation governance instruction according to the voltage adjustment amount.

[0015] In one embodiment, the power quality governance strategy further includes a priority governance strategy; the priority governance strategy is: when the harmonic real-time parameters exceed the second preset harmonic threshold and are less than the first preset harmonic threshold, the three-phase current real-time parameters exceed the second preset current threshold and are less than the first preset current threshold, and the output voltage real-time parameters exceed the second preset voltage threshold and are less than the first preset voltage threshold, determining the parameter excess amount according to each real-time parameter and the corresponding threshold, and preferentially governing the power influence factor with a larger parameter excess amount.

[0016] In one embodiment, the power quality governance strategy further includes a single-item governance strategy; the single-item governance strategy is: when the harmonic real-time parameters exceed the third preset harmonic threshold, performing single-item harmonic governance; or, when the three-phase current real-time parameters exceed the third preset current threshold, performing single-item three-phase imbalance governance; or, when the output voltage real-time parameters exceed the third preset voltage threshold, performing single-item voltage fluctuation governance.

[0017] In an alternative embodiment, a redundancy module is further included. The redundancy module includes a microprocessor, a harmonic management redundancy unit electrically connected to the microprocessor, a three-phase regulation redundancy unit, and a voltage regulation redundancy unit. The microprocessor is connected to the control module to monitor the operating states of the control module, the harmonic management module, the three-phase regulation module, and the voltage regulation module. When the control module fails, the microprocessor takes over the work of the control module and calls the harmonic management redundancy unit, the three-phase regulation redundancy unit, and the voltage regulation redundancy unit to perform harmonic management, three-phase current imbalance management, and voltage fluctuation management respectively. When any one of the harmonic management module, the three-phase regulation module, and the voltage regulation module fails, the microprocessor calls the corresponding redundancy unit to perform corresponding power quality management.

[0018] In an alternative embodiment, the power supply module, the control module, the harmonic management module, the three-phase regulation module, the voltage regulation module, and the redundancy module are all detachable modules embedded in the charging pile housing, and each module is connected through a standard interface.

[0019] In an alternative embodiment, a communication module electrically connected to the control module is further included. The communication module is used for information interaction between the control module and external devices, and the external devices are a grid control center, other charging piles, or a remote monitoring device.

[0020] In an alternative embodiment, a thermal management module is further included. The thermal management module monitors the temperature of the charging pile in real time and controls the air-cooling intensity and liquid-cooling intensity of the heat dissipation system according to the real-time monitored temperature.

[0021] On the other hand, the present application also provides a charging pile, which includes a charging pile housing and the power quality support device for charging piles described in the above embodiments installed on the charging pile housing.

[0022] The above-mentioned power quality support device for charging piles detects harmonics, three-phase current imbalance, and output voltage fluctuation of the power supply module in real time to discover the power quality problems at the load end of the power supply module. After comprehensively considering various power quality problems, a power quality management instruction is generated in combination with the power quality management strategy and transmitted to each power quality management module for corresponding management, so as to dynamically solve the power quality problems such as harmonic pollution, three-phase imbalance, and output voltage fluctuation of the charging pile, effectively ensuring the operation efficiency and charging effect of the charging pile. At the same time, the entire power quality support device adopts a modular design, and each functional module operates independently, improving the convenience of maintenance and upgrade, reducing the downtime, and enhancing the flexibility of the device. Description of the Drawings

[0023] Figure 1 It is a principle block diagram of a power quality support device in one embodiment of the present invention.

[0024] Figure 2 It is a principle block diagram of a redundant module of a power quality support device in one embodiment of the present invention.

[0025] Figure 3 It is a schematic diagram of the connection of various modules of the power quality support device in one embodiment of the present invention.

[0026] Figure 4 This is a schematic diagram of power quality management in one embodiment of the present invention.

[0027] Figure 5 It is a schematic diagram of the installation of various functional modules on a charging pile in one embodiment of the present invention.

[0028] Explanation of reference numerals: 100, power quality support device; 10, power supply module; 20, control module; 30, harmonic control module; 40, three-phase regulation module; 50, voltage regulation module; 60, redundant module; 61, microprocessor; 62, harmonic control redundant unit; 63, three-phase regulation redundant unit; 64, voltage regulation redundant unit; 70, communication module; 80, display module; 200, charging pile shell. DETAILED DESCRIPTION

[0029] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0030] The terms used in this application are for the purpose of describing specific embodiments only and are not intended to limit this application. Unless otherwise defined, the technical or scientific terms used in this application should have the ordinary meaning as understood by those of ordinary skill in the field to which this application pertains. The terms "first", "second" and similar terms used in the specification and claims of this application do not denote any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "an" do not denote a limitation of quantity, but mean that there is at least one. "Plurality" or "several" means at least two. Unless otherwise indicated, terms such as "front", "rear", "lower" and / or "upper" are for convenience of description only and are not limited to a particular position or spatial orientation. The terms "comprising" or "including" and similar terms mean that the elements or items appearing before "comprising" or "including" cover the elements or items listed after "comprising" or "including" and their equivalents, and do not exclude other elements or items. The terms "connected" or "coupled" and similar terms are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect.

[0031] The singular forms "a", "the" and "said" used in the specification and appended claims of this application are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and encompasses any and all possible combinations of one or more of the associated listed items.

[0032] Referring to Figure 1 、 Figure 2 、 Figure 3 As shown in

[0033] The power supply module 10 is installed in the charging pile housing and is detachable. The three-phase connection end of the power supply module 10 is used to connect to the external power grid, and the load end of the power supply module 10 is used to connect to the load device, responsible for providing a stable power output. In addition, the load device can also feed energy back to the power grid (V2G). The power supply module 10 obtains electric energy from the external power grid or the load device, converts the electric energy and transmits it to the load device or the external power grid, realizing the power transmission between the load device and the external power grid.

[0034] The load device is a rechargeable device, such as an electric vehicle, or other machine equipment that relies on electric energy to provide operating power. During the charging process of the electric vehicle, the power module 10 will automatically adjust the output voltage and current according to the battery type, battery capacity and charging status of the vehicle to ensure the safety and efficiency of the charging process; when the vehicle does not need to be charged, the power module 10 can detect and start the feedback mode to feed back the remaining electric energy of the electric vehicle to the power grid, so as to save energy and improve the stability of the power grid. The power module uses an embedded energy management algorithm to intelligently distribute electric energy according to the load conditions of the power grid to optimize energy utilization efficiency.

[0035] The three-phase connection end of the power module 10 includes L1, L2, and L3 phase line ports, which are used to connect the three phase lines of the three-phase AC power supply, usually corresponding to the red, green, and yellow wires, respectively, carrying the power of the three-phase AC power and providing the main power input for the charging pile. The load end of the power module 10 is the DC end. In the process of charging the electric vehicle, the three-phase connection end is the AC power input end, and the load end is the DC power output end.

[0036] Harmonic pollution usually occurs during the transmission of electric energy. Harmonics are current or voltage distortions caused by nonlinear loads during the charging process, and harmonic pollution can affect the stability of the power grid and the life of the charging equipment. In this embodiment, a harmonic control module 30 is used to detect and eliminate harmonic pollution generated during the transmission of electric energy. Specifically, the harmonic control module 30 is connected to the load end of the power module 10, and is used to detect the real-time harmonic parameters of the load end of the power module 10, and transmit them to the control module 20; the harmonic control module 30 receives the harmonic control instructions sent by the control module 20, and performs harmonic control.

[0037] Optionally, the harmonic control module 30 includes: a first current sensor, a first voltage sensor, an active filter and a control unit; the first current sensor is connected to the load end of the power module 10 through the CSI interface, and the first voltage sensor is connected to the load end of the power module 10 through the VSI interface. The first current sensor and the first voltage sensor have high sensitivity and are used to detect the harmonic components carried by the load end output power of the power module 10 in real time, and obtain the real-time harmonic parameters. The real-time harmonic parameters include harmonic current components and harmonic voltage components, that is, harmonic current parameters and harmonic voltage parameters. The real-time harmonic power can be calculated by the harmonic current components and harmonic voltage components. The active filter is connected to the power module 10 through the PI interface to form a parallel structure, and injects a compensation current according to the harmonic control instruction to convert the harmonic power into the fundamental power, thereby realizing harmonic control and reducing the interference of harmonics on the power grid. The control unit is connected to the control module 20 through the CI interface to realize information interaction. The control unit can send the real-time harmonic parameters to the control module 20, and can also receive the harmonic control instructions sent by the control module 20.

[0038] When performing harmonic governance, the harmonic governance module 30 can adaptively adjust the harmonic filtering parameters according to different loads and working environments, so as to meet the harmonic suppression requirements under different power levels.

[0039] In the application of bidirectional charging piles, the problems of harmonic pollution and three-phase imbalance are particularly prominent. Therefore, in order to ensure the quality of power output, three-phase imbalance adjustment is also required.

[0040] The three-phase adjustment module 40 is used to monitor and adjust the balance state of the three-phase current in real time, monitor the current of each phase in real time, and judge the degree of imbalance of the current load according to the monitoring results. When it is detected that the three-phase current of the power supply module 10 is unbalanced, the three-phase adjustment module 40 will automatically adjust the output power of each phase according to the load conditions, that is, by changing the power transmission path of each phase and using energy storage elements for current compensation, so as to balance the three-phase current, reduce the power loss caused by imbalance, and ensure the stability of the power grid.

[0041] Specifically, the three-phase adjustment module 40 is connected to each phase line of the three-phase connection end of the power supply module 10, used to detect the real-time parameters of the three-phase current of the power supply module 10 and transmit them to the control module 20; the three-phase adjustment module 40 receives the three-phase adjustment instructions sent by the control module 20 and executes the governance of three-phase current imbalance.

[0042] Optionally, the three-phase adjustment module 40 includes: a second current sensor, an energy storage element, and a regulator; the second current sensor is connected to the three-phase connection end of the power supply module 10 through the CSI interface to monitor the unbalanced component of the current of each phase in real time; the energy storage element is a capacitor or a battery, connected to the power supply module 10 through the SEI interface, used to store and release energy to balance the three-phase current; the regulator: is an IGBT or MOSFET switch, connected to the three-phase circuit of the power supply module 10 through the PI interface, and the control end of the regulator is connected to the control module 20, used to receive the three-phase adjustment instructions and adjust the current of each phase according to the three-phase adjustment instructions.

[0043] The voltage adjustment module 50 is connected to the load end of the power supply module 10, used to detect the real-time parameters of the output voltage of the load end of the power supply module 10 and transmit them to the control module 20; the voltage adjustment module 50 receives the voltage fluctuation governance instructions sent by the control module 20 and executes the voltage fluctuation governance.

[0044] Specifically, the voltage adjustment module 50 includes a second voltage sensor and a bus voltage regulator. The second voltage sensor is connected to the load end of the power supply module 10 through the VSI interface, used to detect the real-time parameters of the output voltage; the bus voltage regulator is directly connected to the DC bus of the power supply module 10 to dynamically adjust the voltage amplitude.

[0045] The control module 20 is the intelligent core of the entire power quality support device and the charging pile, and is responsible for coordinating the operation of various functional modules to realize the adaptive power quality support function of the system; the control module 20 has a built-in intelligent algorithm, which can dynamically adjust the output power and working mode of the charging pile according to the charging needs of the vehicle, the load conditions of the power grid and other real-time monitoring data, thereby improving the safety and efficiency of the charging process; the control module 20 receives feedback data from the harmonic control module 30 and the three-phase regulation module 40, and analyzes the operating status of the charging pile in real time, data processing and optimization algorithms, and promptly discovers and solves power quality problems.

[0046] Specifically, the control module 20 receives real-time parameters of harmonics, real-time parameters of three-phase current and real-time parameters of output voltage, generates power quality management instructions in combination with the power quality management strategy, sends the power quality management instructions to the corresponding module, and controls the execution of corresponding power quality management.

[0047] Among them, the power quality management instructions include harmonic management instructions, three-phase regulation instructions and voltage fluctuation management instructions. The control module 20 sends the harmonic management instructions to the harmonic management module 30, sends the three-phase regulation instructions to the three-phase regulation module 40, and sends the voltage fluctuation management instructions to the voltage regulation module 50, and controls the execution of the corresponding power quality management.

[0048] The technical solution of this embodiment detects the output power quality problems of the load end of the power module by performing real-time harmonic detection, three-phase current imbalance detection, and output voltage fluctuation detection on the power module. After comprehensively considering various power quality problems, it generates power quality management instructions in combination with the power quality management strategy and transmits them to each power quality management module for corresponding management, thereby dynamically solving the power quality problems of the charging pile such as harmonic pollution, three-phase imbalance, and output voltage fluctuation, and effectively ensuring the operating efficiency and charging effect of the charging pile. At the same time, the entire power quality support device adopts a modular design, and each functional module operates independently, which improves the convenience of maintenance and upgrading, reduces downtime, and enhances the flexibility of the equipment.

[0049] In an optional embodiment, if Figure 4As shown, the power quality governance strategy includes a collaborative governance strategy, which is as follows: when the real-time harmonic parameters exceed the first preset harmonic threshold, the real-time three-phase current parameters exceed the first preset current threshold, and the real-time output voltage parameters exceed the first preset voltage threshold, the optimal values of each function variable are determined based on the minimization of a pre-constructed comprehensive governance objective function, and corresponding harmonic governance instructions, three-phase adjustment instructions, and voltage fluctuation governance instructions are generated according to the optimal values of each function variable. Among them, the first preset harmonic threshold, the first preset current threshold, and the first preset voltage threshold can be determined according to the application scenario and the actual circuit of the charging pile, and specific numerical limits are not set in this embodiment.

[0050] The method for minimizing the comprehensive governance objective function is as follows:

[0051] 。

[0052] Among them, is the active power of the th harmonic, is the reactive power of the th harmonic, is the vector difference of the three-phase unbalanced current, is the fluctuation amplitude of the output voltage, is the harmonic governance weight, is the three-phase unbalance governance weight, is the voltage governance weight.

[0053] In this embodiment, the harmonic governance weight, the three-phase unbalance governance weight, and the voltage governance weight are determined according to the constraint requirements of each corresponding index in the preset power quality standard. In actual engineering applications, reasonable initial weight values are obtained based on existing power grid operation experience, the working state of the charging pile, and the power quality governance requirements. Optionally, based on power quality standards (such as IEEE 519-2014, GB / T 15543-2008), weights can be allocated according to the constraint requirements of each index (harmonics, three-phase unbalance, voltage fluctuation). The three governance weights can be flexibly adjusted according to the actual situation. In a high-harmonic pollution environment, the harmonic governance weight can be appropriately increased, and the three-phase unbalance governance weight and the voltage governance weight can be reduced; in the case of severe three-phase load imbalance, the three-phase unbalance governance weight can be increased to enhance the three-phase adjustment ability.

[0054] The constraint conditions of the comprehensive governance objective function include: voltage fluctuation constraint condition: , is the maximum fluctuation limit of the preset output voltage; three-phase unbalance constraint condition: , is the maximum vector limit of the preset three-phase unbalanced current; harmonic power constraint condition: , is the maximum limit of the active power of the th harmonic preset, is the maximum limit of the reactive power of the th harmonic preset.

[0055] The optimal values of the function variables include: the active power of the th harmonic and the reactive power optimal values, the optimal value of the three-phase unbalanced current vector difference and the optimal value of the fluctuation amplitude of the output voltage .

[0056] According to the optimal values of each function variable, corresponding power quality management instructions are generated, including: determining the compensation current according to the difference between the optimal values of the active power and the reactive power of the th harmonic and the real-time harmonic power at the load end of the power supply module, generating a harmonic management instruction according to the compensation current, and the real-time harmonic power is determined by the real-time harmonic parameters; determining the three-phase current adjustment amount according to the difference between the optimal value of the three-phase unbalanced current vector difference and the real-time three-phase current parameters of the power supply module, generating a three-phase adjustment instruction according to the three-phase current adjustment amount; determining the voltage adjustment amount according to the sum of the optimal value of the fluctuation amplitude of the output voltage and the real-time output voltage parameters of the power supply module, and generating a voltage fluctuation management instruction according to the voltage adjustment amount.

[0057] In an optional embodiment, as Figure 4 shown, the power quality management strategy further includes a priority management strategy. The priority management strategy is: when the real-time harmonic parameters exceed the second preset harmonic threshold and are less than the first preset harmonic threshold, the real-time three-phase current parameters exceed the second preset current threshold and are less than the first preset current threshold, and the real-time output voltage parameters exceed the second preset voltage threshold and are less than the first preset voltage threshold, determining the parameter excess amount according to each real-time parameter and the corresponding threshold, and preferentially managing the power quality influencing factors with a larger parameter excess amount. Among them, the second preset harmonic threshold, the second preset current threshold, and the second preset voltage threshold can be determined according to the application scenario and the actual circuit of the charging pile, and specific numerical values are not limited in this embodiment.

[0058] In an optional embodiment, each optimal variable can be determined by minimizing the priority management objective function, and the processing method of minimizing the priority management objective function is , where is the fluctuation amplitude of the output voltage, is the vector difference of unbalanced three-phase currents, is the active power of the is the reactive power of the

[0059] The constraint conditions of the priority governance objective function include: First, the voltage fluctuation constraint condition: , is the maximum fluctuation limit of the preset output voltage; Second, the three-phase unbalance constraint condition: , is the maximum vector limit of the preset unbalanced three-phase current; Third, the harmonic power constraint condition: , is the maximum limit of the active power of the preset harmonic, is the maximum limit of the reactive power of the preset harmonic.

[0060] Under the harmonic power constraint condition, the power quality influencing factors with the largest parameter excess are determined for priority governance, then the power quality influencing factors with larger parameter excess are determined for governance, and finally the remaining power quality influencing factors are governed.

[0061] In an alternative embodiment, as Figure 4 shown, the power quality governance strategy further includes a single-item governance strategy. The single-item governance strategy is: when the real-time harmonic parameters exceed the third preset harmonic threshold, harmonic single-item governance is performed; or, when the real-time three-phase current parameters exceed the third preset current threshold, three-phase unbalance single-item governance is performed; or, when the real-time output voltage parameters exceed the third preset voltage threshold, voltage fluctuation single-item governance is performed. Among them, the third preset harmonic threshold, the third preset current threshold, and the third preset voltage threshold can be determined according to the application scenario and the actual circuit of the charging pile, and no specific numerical limitations are set in this embodiment.

[0062] During harmonic single-item governance, the active filter is controlled by a harmonic governance instruction to inject a compensation current into the power supply module, converting the harmonic power into fundamental power, thereby achieving harmonic governance and reducing the interference of harmonics on the power grid. Among them, the compensation current is the reverse harmonic current, and the reverse harmonic current can be calculated according to the following formula: , is the reverse harmonic current, is the detected current component of the

[0063] During three-phase unbalance single-item governance, the regulator in the module receives the three-phase regulation instruction sent by the control module 20, controls the energy storage element to release electrical energy to balance the three-phase current, and automatically adjusts the output power of each phase to satisfy and two conditions

[0064] When performing single-item governance of voltage fluctuations, the bus voltage regulator is connected to the control module 20, receives the voltage fluctuation governance instruction, and adjusts the DC bus voltage so that the output voltage fluctuates within a certain range and tends to be stable. The allowable output voltage fluctuation needs to meet the conditions: , is the change amount of the voltage; is the proportional coefficient, which determines the influence degree of the difference between the actual voltage and the reference voltage on the voltage change amount; is the reference voltage, which is a set target voltage value; is the actual voltage value existing in the circuit. Based on this formula, the output voltage can be adjusted according to the deviation between the actual voltage and the reference voltage to reach the desired voltage level.

[0065] Each functional module of the power quality support device will inevitably have faults. Usually, if a certain module fails, the whole machine needs to be shut down for processing, and the power supply module cannot continue to work. To avoid this situation, in an alternative embodiment, a redundant module 60 is introduced. The redundant module 60 is used as a backup unit of the main functional module. When any module fails, the redundant module 60 can quickly take over the task, replace the key functional modules of the charging pile to work, ensure the continuous operation of the system, and further reduce the equipment downtime; it not only greatly simplifies the equipment maintenance process, but also enhances the reliability and fault tolerance of the equipment; at the same time, this design is convenient for future upgrades and expansions.

[0066] In a specific embodiment, as Figure 2 shown, the redundant module 60 includes a microprocessor 61, a harmonic governance redundant unit 62 electrically connected to the microprocessor 61, a three-phase regulation redundant unit 63, and a voltage regulation redundant unit 64; the microprocessor 61 is connected to the control module 20 to monitor the operating states of the control module 20, the harmonic governance module 30, the three-phase regulation module 40, and the voltage regulation module 50; when the control module 20 fails, the microprocessor 61 takes over the work of the control module 20 and calls the harmonic governance redundant unit 62, the three-phase regulation redundant unit 63, and the voltage regulation redundant unit 64 to perform harmonic governance, three-phase current unbalance governance, and voltage fluctuation governance respectively; when any module in the harmonic governance module 30, the three-phase regulation module 40, and the voltage regulation module 50 fails, the microprocessor 61 automatically calls the corresponding redundant unit to perform the corresponding power quality governance, realizing the module-level hot backup and fast replacement functions, thereby improving the reliability and system stability of the charging pile.

[0067] In addition, the redundancy module 60 can analyze the cause of the fault through an intelligent diagnostic algorithm and pass the fault information to the control module 20 for subsequent maintenance. In one embodiment, the microcontroller collects the working parameters of the harmonic control module and the three-phase unbalanced module in real time, such as the current, voltage, temperature, filter status of each channel, and key data of the internal communication status of the module. In the system design stage, a threshold range for normal operation is set for each key data, and the microprocessor will compare the key data collected in real time with these preset thresholds to determine whether there is an abnormal deviation. For example, if the filter state output by the harmonic control module is abnormal, it may indicate that the active filter is damaged or the control signal is abnormal; and if the current deviation of a phase in the three-phase unbalanced module is too large, it may indicate that there is a problem with the regulator or sensor of the module. After the redundant module determines the cause of the fault, it will output the corresponding fault code for reference by maintenance personnel.

[0068] The existing smart charging pile hardware design is relatively simple and lacks a modular layout. It is difficult to flexibly configure according to actual needs and is difficult to maintain and upgrade.

[0069] In an optional embodiment, if Figure 5 As shown, the power module 10, control module 20, harmonic control module 30, three-phase regulation module 40, voltage regulation module 50, and redundancy module 60 are all detachable modules embedded in the charging pile housing 200. Each module is independently partitioned and connected through a standard interface, which has higher flexibility. Specifically, the power module 10 is embedded in the charging pile housing 200, and the harmonic control module 30, three-phase regulation module 40, and voltage regulation module 50 are installed on the outside of the charging pile housing 200, which can be flexibly disassembled and replaced. Each functional module uses silicon carbide power devices to improve power conversion efficiency and reduce power loss.

[0070] Each functional module is independently partitioned and has backup capabilities, which facilitates rapid maintenance, upgrades, and fault switching, minimizing equipment downtime. The combination of modular and redundant design also prevents different modules from interfering with each other, ensuring stable operation of the equipment under high load conditions, and effectively improving the power quality support capability, greatly improving the maintainability, scalability, and reliability of the charging pile.

[0071] In addition, in an optional embodiment, the power quality support device 100 also includes a communication module 70 electrically connected to the control module 20, and the communication module 70 is used for information exchange between the control module 20 and external devices, that is, for real-time interaction and remote control of data. The external device is a power grid control center, other charging piles, or a remote monitoring device. Specifically, the communication module 70 is interconnected with the power grid control center or multiple charging piles through a wireless network, Ethernet or other communication methods, including a remote monitoring function. The user can view the operating status of the charging pile in real time through the background system or mobile application, and analyze its power quality support. In addition, data exchange can be carried out between multiple charging piles, and multiple charging piles can be clustered and coordinated.

[0072] The heat dissipation design of the charging pile in the prior art is often not perfect, and long-term high-power operation can easily lead to overheating of the equipment, affecting the life and stability of the charging pile. In order to ensure the operating environment of the charging pile, the power quality support device also includes a thermal management module, which monitors the temperature of the charging pile in real time and controls the air cooling intensity and liquid cooling intensity of the heat dissipation system according to the real-time monitored temperature.

[0073] The heat dissipation system includes an air cooling system and a liquid cooling system, which are installed on the left and right sides of the charging pile respectively. The air cooling system includes a high-speed fan, which introduces air into the interior of the charging pile shell and forms a continuous airflow circulation to quickly remove the heat generated by the equipment during operation, effectively reducing the overall temperature of the equipment; the liquid cooling system is mainly aimed at high-power density components (such as power modules, harmonic control modules, etc.), and directly removes the generated heat through the flow of coolant to ensure that these high-heat components maintain normal operating temperatures during long-term operation. The liquid cooling system is installed in contact with the power module and harmonic control module.

[0074] In an optional embodiment, the power quality support device further includes a display module 80, specifically a display screen, which is installed on the top of the charging pile housing to facilitate staff to view data or make adjustments.

[0075] In an optional embodiment, the power quality support device also includes a power quality monitoring module (not shown) for real-time monitoring of the power quality of the power module 10 and displaying it through the display module 80 so that the staff can understand the power quality in a timely manner.

[0076] Compared with the prior art, the technical solution of the embodiment of the present application performs real-time harmonic detection, three-phase current imbalance detection, and output voltage fluctuation detection on the power module to discover the output power quality problems at the load end of the power module. After comprehensively considering various power quality problems, it generates power quality management instructions in combination with the power quality management strategy, and transmits them to each power quality management module for corresponding management, thereby dynamically solving the power quality problems of the charging pile such as harmonic pollution, three-phase imbalance, and output voltage fluctuation, and effectively ensuring the operating efficiency and charging effect of the charging pile.

[0077] At the same time, the entire power quality support device adopts a modular design. Each functional module operates independently and can be replaced independently, which improves the convenience of maintenance and upgrades, reduces downtime, and enhances the flexibility of the equipment.

[0078] The introduction of redundant modules further improves the reliability and fault tolerance of the system. When any functional module fails, the redundant module can quickly take over the task to ensure the continuous operation of the system and minimize the impact on charging services.

[0079] The efficient heat dissipation system combines air cooling and liquid cooling to optimize the heat dissipation channel, ensure the stability of the equipment for long-term operation under high load, and extend the service life of the equipment.

[0080] In addition, the communication module enables interaction between multiple charging piles, supports the coordinated operation of multiple charging stations, and improves the overall flexibility and efficiency of the system.

[0081] The present application also provides a charging pile, such as Figure 5 As shown, the charging pile includes a charging pile housing 200 and a power quality support device for the charging pile as described in the above embodiment and installed on the charging pile housing 200 .

[0082] The charging pile shell 200 includes a main shell and a bottom stabilizing reinforcement component. The charging pile shell 200 is made of high-strength, corrosion-resistant metal material. The shell has IP-level waterproof and dustproof capabilities, and can maintain normal operation in harsh environments such as heavy rain and dust. It uses high-strength materials and undergoes special reinforcement treatment, which can effectively prevent equipment failures caused by external impact or physical damage; the material and coating are specially treated to have high temperature resistance, low temperature resistance and corrosion resistance, ensuring that the charging pile can still work stably under extreme climatic conditions. The power quality support device is the same as that recorded in the above embodiment, and this embodiment will not be repeated.

[0083] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, 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 specification.

[0084] The above embodiments only represent several implementation manners of the present application. The description thereof is relatively specific and detailed, but it should not be construed as a limitation to the scope of the patented application. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present application, several modifications and improvements can still be made, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the appended claims.

Claims

1. A power quality support device applied to a charging pile, characterized in that: It includes a power supply module, a control module, and a harmonic control module, a three-phase regulation module, and a voltage regulation module electrically connected to the control module; The three-phase connection end of the power module is used to connect to the external power grid, and the load end is used to connect to the load device. The power module obtains electric energy from the external power grid or the load device, and converts the electric energy and transmits it to the load device or the external power grid; The harmonic control module is used to detect the real-time harmonic parameters of the load end of the power module, transmit them to the control module, and receive the harmonic control instructions sent by the control module to perform harmonic control; The three-phase regulation module is used to detect the real-time parameters of the three-phase current of the three-phase connection end of the power module, transmit them to the control module, and receive the three-phase regulation instructions sent by the control module to perform three-phase current imbalance management; The voltage regulating module is used to detect the real-time parameters of the output voltage at the load end of the power module, transmit them to the control module, and receive the voltage fluctuation management instruction sent by the control module to perform voltage fluctuation management; The control module receives the harmonic real-time parameter, the three-phase current real-time parameter and the output voltage real-time parameter, generates a power quality management instruction in combination with the power quality management strategy, sends the power quality management instruction to the corresponding module, and controls the execution of the corresponding power quality management, wherein the power quality management instruction includes the harmonic management instruction, the three-phase regulation instruction and the voltage fluctuation management instruction; The power quality management strategy includes a collaborative management strategy; the collaborative management strategy is: when the harmonic real-time parameter exceeds the first preset harmonic threshold, the three-phase current real-time parameter exceeds the first preset current threshold, and the output voltage real-time parameter exceeds the first preset voltage threshold, based on the minimization processing of the pre-constructed comprehensive management objective function, the optimal value of each function variable is determined, and the corresponding power quality management instruction is generated according to the optimal value of each function variable; Among them, the minimization processing method of the comprehensive management objective function is: ， in, For the The active power of subharmonics, For the The reactive power of subharmonics, is the three-phase unbalanced current vector difference, is the fluctuation amplitude of the output voltage, is the harmonic control weight, is the three-phase imbalance governance weight, is the voltage management weight; The constraints of the comprehensive governance objective function include: Voltage fluctuation constraints: , is the preset maximum fluctuation limit of the output voltage, Three-phase unbalance constraints: , is the preset maximum vector limit of the three-phase unbalanced current, Harmonic power constraints: , For the preset The maximum limit of active power of subharmonics, For the preset Maximum limit of reactive power of subharmonics; The optimal values ​​of the function variables include: Active power of subharmonics And reactive power The optimal value of the three-phase unbalanced current vector difference The optimal value of and the fluctuation amplitude of the output voltage The best value of .

2. The power quality support device for a charging pile according to claim 1, characterized in that: The generating the corresponding power quality management instruction according to the optimal value of each function variable includes: According to Active power of subharmonics And reactive power The compensation current is determined by the difference between the optimal value of and the real-time harmonic power at the load end of the power module, and the harmonic control instruction is generated according to the compensation current, wherein the real-time harmonic power is determined by the harmonic real-time parameter; According to the three-phase unbalanced current vector difference Determine the three-phase current regulation amount based on the difference between the optimal value and the three-phase current real-time parameter of the power module, and generate the three-phase regulation instruction according to the three-phase current regulation amount; According to the fluctuation amplitude of the output voltage The voltage regulation amount is determined by the sum of the optimal value and the real-time parameter of the output voltage of the power module, and the voltage fluctuation control instruction is generated according to the voltage regulation amount.

3. The power quality support device for a charging pile according to claim 1, characterized in that: The power quality management strategy also includes a priority management strategy; The priority management strategy is: when the harmonic real-time parameter exceeds the second preset harmonic threshold and is less than the first preset harmonic threshold, the three-phase current real-time parameter exceeds the second preset current threshold and is less than the first preset current threshold, and the output voltage real-time parameter exceeds the second preset voltage threshold and is less than the first preset voltage threshold, the parameter excess amount is determined according to each real-time parameter and the corresponding threshold, and the electric energy influencing factors with larger parameter excess amount are prioritized for management.

4. The power quality support device for a charging pile according to claim 1, characterized in that: The power quality management strategy also includes a single management strategy; The single control strategy is: when the real-time parameter of the harmonic exceeds the third preset harmonic threshold, single control of the harmonic is performed; or, when the real-time parameter of the three-phase current exceeds the third preset current threshold, single control of the three-phase imbalance is performed; or, when the real-time parameter of the output voltage exceeds the third preset voltage threshold, single control of the voltage fluctuation is performed.

5. The power quality support device for a charging pile according to claim 1, characterized in that: It also includes a redundant module, which includes a microprocessor, a harmonic control redundant unit electrically connected to the microprocessor, a three-phase regulation redundant unit, and a voltage regulation redundant unit; The microprocessor is connected to the control module to monitor the operating status of the control module, the harmonic control module, the three-phase regulation module, and the voltage regulation module; When the control module fails, the microprocessor takes over the work of the control module, calls the harmonic control redundant unit, the three-phase regulation redundant unit, and the voltage regulation redundant unit, and correspondingly performs harmonic control, three-phase current unbalance control, and voltage fluctuation control; When any of the harmonic control module, the three-phase regulation module, and the voltage regulation module fails, the microprocessor calls the corresponding redundant unit to perform corresponding power quality control.

6. The power quality support device for a charging pile according to claim 5, characterized in that: The power module, the control module, the harmonic control module, the three-phase regulation module, the voltage regulation module, and the redundancy module are all detachable modules embedded in the charging pile housing, and the modules are connected through standard interfaces.

7. The power quality support device for a charging pile according to claim 1, characterized in that: It also includes a communication module electrically connected to the control module, and the communication module is used for information exchange between the control module and an external device, wherein the external device is a power grid control center, other charging piles, or a remote monitoring device.

8. The power quality support device for a charging pile according to claim 1, characterized in that: It also includes a thermal management module, which monitors the temperature of the charging pile in real time and controls the air cooling intensity and liquid cooling intensity of the heat dissipation system according to the real-time monitored temperature.

9. A charging pile, characterized in that: It comprises a charging pile shell, and a power quality support device applied to a charging pile as claimed in any one of claims 1 to 8 installed on the charging pile shell.

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