Charging pile power control system and method based on power line carrier communication

Abstract

The invention discloses a charging pile power control system and method based on power line carrier communication, the total power of a power supply network is detected in real time through a host monitor, a regulation and control instruction is broadcasted to a charging pile by using a power line carrier technology, and the charging power is dynamically adjusted in combination with a hierarchical response strategy. The system can be applied to household, industrial and commercial and power grid scenes, solves the overload problem caused by centralized use of high-power charging equipment, guarantees the power utilization safety, and optimizes the energy distribution efficiency.

Description

Technical Field

[0001] This invention belongs to the field of power distribution and intelligent charging technology, specifically relating to a control system and method for charging pile power based on power line carrier communication. Background Technology

[0002] Currently, new energy vehicles are widely used, posing a challenge to the charging power distribution technology of charging stations. The mainstream power distribution technologies currently in use include the following: 1. Fixed power distribution mode: Traditional power distribution systems use fixed power installation. Considering power supply safety, the total installed load power needs to be less than the power supply power or the total power supply capacity needs to be increased to solve the problem of continuous power supply. In reality, it is unlikely that all loads will work at the same time or at maximum power. When the total power supply capacity is insufficient, it is impossible to determine the number of loads working at the same time, which makes power supply allocation difficult and can easily lead to power distribution overload or waste of power distribution resources.

[0003] 2. Priority control: Some systems set the priority of charging piles through the platform. However, when the total power supply capacity is insufficient, some vehicles with charging needs may not be able to charge at their destination in time, making it impossible to distribute resources evenly and causing inconvenience to users.

[0004] 3. Remote Cloud Platform Control Strategy: This strategy uses a cloud platform to calculate the real-time power consumption of all charging stations and compares it to the maximum usable total power limit. Power adjustments are then selectively made for users charging at the highest power or those meeting VIP policy requirements, ensuring the overall load safety. However, this method is limited by the data upload interval for calculating charging power, resulting in slow response times, a lack of automated coordination capabilities, and difficulty in handling instantaneous power fluctuations. While theoretically sound, it cannot guarantee electrical safety in scenarios with a large number of users.

[0005] 4. Single device control strategy: The charging pile can use a time-sharing automatic power limiting strategy. By making empirical judgments on the usage period, the charging pile can be set to limit the power during peak hours. This scheme lacks a global power load coordination management mechanism and is also an unsafe control strategy.

[0006] It is evident that current technologies cannot address the shortcomings of traditional power consumption strategies, such as the lack of effective load management, the inability to fully utilize the maximum efficiency of the power supply side, and the inability of the distribution network to install electrical equipment beyond its power supply range. This poses difficulties for the large-scale installation of charging piles within the power supply area and hinders the rapid deployment of a large number of electric vehicle charging stations. Furthermore, when the total power of the public transformer group approaches or exceeds the threshold, there is a lack of rapid and adaptive multi-device collaborative load reduction mechanisms and a lack of dynamic hierarchical control capabilities for charging pile power, making it difficult to balance charging demand with electrical safety. Summary of the Invention

[0007] To address the shortcomings of existing technologies, the purpose of this invention is to provide a charging pile collaborative management system based on real-time power load monitoring and hierarchical control. By dynamically adjusting the power of charging piles, the system ensures that the total power of the power supply network is always below a safe threshold, while optimizing power distribution efficiency and safety in multiple scenarios (home, industrial and commercial, and power grid).

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a power control system for charging piles based on power line carrier communication, comprising: A power supply unit used to provide electricity; The charging equipment unit is electrically connected to the power supply unit and is used to charge the vehicle, including several charging piles and a decoder module. The power monitoring unit is used to collect the current and voltage data of the system in real time to calculate the power and generate corresponding digital signals to control the charging equipment unit. It includes a Hall sensor, a three-phase power calculation chip, and a power line carrier modulation module. A power line carrier communication network is used to transmit the digital signal generated by the power monitoring unit to the decoder module; The decoder module can analyze and convert the digital signal into dynamic control commands that are defined differently in response to different overload coefficients, thereby controlling the charging power of the charging pile.

[0009] As a preferred technical solution of the present invention, it also includes a cloud management platform and a State Grid integrated terminal management system, wherein the cloud management platform and the State Grid integrated terminal management system can provide dynamic threshold setting, historical data storage and remote policy distribution functions.

[0010] As a preferred embodiment of the present invention, the physical layer specification of the power line carrier communication network conforms to the IEEE 1901.1 PLC standard, the communication protocol stack conforms to the PLBUS PLC protocol, and advanced technologies such as OFDM modulation and time-frequency domain channel interleaving are used to ensure communication robustness. The supported frequency band range is 2 to 12 MHz, the default operating frequency band is 2.4 to 5.7 MHz, the communication rate is 120 kbps to 1.2 Mbps, and the typical point-to-point communication distance is 200 to 500 meters.

[0011] The present invention also provides a power control method for charging piles based on power line carrier communication implemented through the above-described system, comprising: Acquire real-time current and voltage data and calculate real-time power; Based on the real-time power and the preset maximum safe power threshold, the overload factor is determined; The control mechanism is determined based on the overload coefficient, and the digital signal of the control mechanism is transmitted to the decoder module of each charging pile for decoding via power line carrier communication. The decoder module converts the digital signal into dynamic PWM duty cycle control commands corresponding to different overload coefficients to adjust the power of the charging pile.

[0012] As a preferred embodiment of the present invention, the current and voltage data include the total current and total voltage of the system, as well as the current and voltage detected autonomously by each charging pile.

[0013] As a preferred embodiment of the present invention, the overload factor is the ratio of the real-time power in the system to the maximum safe power threshold. When the overload coefficient is ≥ k1, the first-level control mechanism is activated: that is, the power of the charging pile with power greater than p1 is reduced in steps by gradient G1. When the overload coefficient is greater than or equal to k2, a secondary control mechanism is activated: the power of charging piles with power greater than p1 is directly reduced by G2.

[0014] When the overload coefficient is ≥1.0, a three-level control mechanism is activated: charging piles with power p2 < power ≤ p3 will have an additional 20% step power attenuation, while charging piles with power greater than p3 will have their power directly reduced to the minimum value. Among them, k1 <k2<1,p1>p3>p2 。

[0015] As a preferred technical solution of the present invention, after the control mechanism is executed, that is, when the overload coefficient is <k1, the charging pile after the power is adjusted gradually restores the power over a period of time to avoid instantaneous overload. The recovery process is controlled by the overload coefficient to determine whether to gradually restore to the maximum output power.

[0016] By adopting the above technical solution, the beneficial effects of this invention are as follows: Through power line carrier information broadcasting and a multi-level response strategy, second-level full-domain power coordination adjustment of charging piles is achieved, thereby realizing dynamic coordinated cluster control. Deep binding of PWM duty cycle control and PLC carrier communication ensures precise matching between control commands and charging behavior. Charging piles automatically execute control without user intervention. Charging piles automatically adjust power according to the control strategy, ensuring power safety. Based on this control strategy, using open communication protocols and overload coefficient response open protocols, it can be used for different types of charging piles. A large number of charging piles can be added freely according to application needs, regardless of the charging pile brand or the difference between network-operated charging piles and privately installed charging piles. Furthermore, it can maximize the output efficiency of existing public transformer groups, reducing excessive redundancy waste in public transformer groups. Attached Figure Description

[0017] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0018] Figure 1 This is a schematic diagram of the architecture of Embodiment 1 of the present invention; Figure 2 This is a flowchart of the control mechanism in Embodiment 2 of the present invention; Figure 3 This is a flowchart illustrating the adjustment and recovery process of the charging pile when it is turned on, from an overload coefficient of less than 0.9 to an overload coefficient of greater than 1.0, in Embodiment 2 of the present invention. Figure 4 This is a flowchart of the device in Embodiment 2 of the present invention when it is already in the Level 2 control state; Figure 5 This is a flowchart of the device in the 3rd level control state in Embodiment 2 of the present invention.

[0019] In the diagram: 1. Power supply unit 1; 2. Charging equipment unit; 21. Charging pile; 22. Decoder module; 3. Power monitoring unit. Detailed Implementation

[0020] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0021] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the invention. For example, as used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0022] The following terms are used: PWM duty cycle: refers to the ratio of pulse width to pulse period in a pulse width modulation (PWM) signal, that is, the proportion of the time the signal is high-level within a period.

[0023] PLC: refers to power line communication or power line carrier (PLC) communication, which is a special communication method that uses high-voltage power lines (usually 35kV and above in the field of power line carrier), medium-voltage power lines (10kV), or low-voltage distribution lines (380 / 220V user lines) as information transmission media to transmit voice or data. Example 1

[0024] This embodiment relates to a power control system for charging piles based on power line carrier communication, as shown in the attached figure. Figure 1 As shown, the system includes a power supply unit 1 for providing power, a charging equipment unit 2 electrically connected to the power supply unit 1 for charging vehicles (specifically including several charging piles 21 and a decoder module 22), and a power monitoring unit 3 for real-time acquisition of current and voltage data from the system to calculate power and generate corresponding digital signals to control the charging equipment unit 2. This unit includes a Hall sensor, a three-phase power calculation chip, and a power line carrier modulation module. All these units communicate via a power line carrier communication network 4, which transmits the digital signals generated by the power monitoring unit 3 to the decoder module 22. Specifically, the decoder module 22 converts the digital signals into PWM duty cycle control commands to control the charging power of the charging piles 21. Furthermore, to provide dynamic threshold setting, historical data storage, and remote policy distribution functions, a cloud management platform and a State Grid integrated terminal management system (not shown in the figure) are also included.

[0025] The physical layer specification of the power line carrier communication network conforms to the IEEE 1901.1 PLC standard, and the communication protocol stack conforms to the PLBUS PLC protocol. Advanced technologies such as OFDM modulation and time-frequency domain channel interleaving are used to ensure communication robustness. The supported frequency band range is 2 to 12 MHz, the default operating frequency band is 2.4 to 5.7 MHz, the communication rate is 120 kbps to 1.2 Mbps, and the typical point-to-point communication distance is 200 to 500 meters.

[0026] This system has a wide range of applications, suitable for small locations such as homes as well as densely populated commercial charging stations. The maximum load threshold can be flexibly adjusted according to actual conditions and needs. The specific method is described in Example 2. Example 2

[0027] This embodiment is a power control method for charging piles based on power line carrier communication, implemented using the system of Embodiment 1, including: The power monitoring unit collects current and voltage data from the system in real time and calculates the real-time power to form a digital signal for the control mechanism. The system determines the overload factor based on real-time power and a pre-set maximum safe power threshold. The overload factor is the ratio of real-time power to the maximum safe power threshold in the system. The system determines the control mechanism based on the overload factor and transmits the digital signal of the control mechanism to the decoder module of each charging pile through power line carrier communication for decoding; The decoder module converts the digital signal into a PWM duty cycle control command to adjust the power of the charging pile.

[0028] The specific adjustment method is as follows: When the overload factor is ≥0.9, the first-level control mechanism is activated: charging piles with power greater than 6kW will have their power reduced by 30% in stages.

[0029] When the overload factor is ≥0.95, the secondary control mechanism is activated: the power of charging piles with a power greater than 6kW is directly reduced by 60%.

[0030] When the overload factor is ≥1.0, a three-level control mechanism is activated: charging piles with power ≤4.2kW ​​and a power of 3kW or less will have an additional 20% step power reduction, while charging piles with power greater than 4.2kW ​​will have their power reduced directly to the minimum value.

[0031] After the control mechanism is implemented, i.e. when the overload coefficient is <0.9, the charging pile after the power adjustment will gradually restore the power over a period of time to avoid instantaneous overload. The restoration process is controlled by the overload coefficient to determine whether it gradually restores to the maximum output power.

[0032] Taking a residential setting as an example, the power monitoring unit of this system is installed at the entrance of the home's electrical distribution box, with a maximum load threshold set at 10kW. Assuming that a new energy vehicle charging (7kW) and an air conditioner (3kW) are running simultaneously, reaching a total power of 10kW, the first-level control mechanism is triggered. The charging pile automatically reduces its load to 4.9kW (a 30% reduction), and the total power drops to 7.9kW, returning to a safe range. With the overload factor reduced to 79%, the charging pile decides whether to gradually restore its power to 6kW based on its full recovery power and the remaining total power safety, achieving charging with maximum safety and efficiency.

[0033] Taking the system installed in a commercial charging station as an example, assuming the maximum load of the public transformer group is 600kW, connecting 120 charging piles (each with a maximum power of 7kW), with 40 piles connected to each of the three phases, the maximum load available for charging pile applications is 540 / 3 = 180kW per phase. Starting with control, the public transformer is allowed to momentarily exceed 10% of the total load. With 40 devices simultaneously outputting a maximum of 280kW, this significantly exceeds the maximum single-phase power of 180kW, requiring a control strategy for protection. The following steps employ a single-phase control method, such as... Figures 2 to 5 As shown: When all 24 charging piles are operating at full capacity, the total power is 24 × 7 = 168KW. The power overload factor is approximately 168KW ÷ 180KW ≈ 0.93, triggering Level 1 regulation. The charging piles themselves receive this overload factor greater than 0.9, and each device will automatically switch its output PWM duty cycle from 53.3% to 37.3%, reducing the vehicle's power demand to 24 × 4.9 = 117.6KW. The detected power overload factor at this point is 117.6 ÷ 180 = 0.65. These charging piles do not need to further change their PWM output. However, some charging piles may have already reduced their power when the vehicle's response speed is inconsistent. Other unregulated devices may operate at close to 180KW to achieve optimal efficiency. When the detected output slightly exceeds 180KW, unregulated charging piles, or after a prolonged period exceeding 30 minutes, may return to maximum output, triggering regulation. In this case, unregulated devices will automatically reduce their power.

[0034] When the regulation is implemented, a large number of charging piles will basically reach a balance of around 180KW after charging for more than 30 minutes, and will generally be controlled under the level 1 overload factor. Newly opened charging piles will cause a brief trigger of level 2 or 3 regulation, but will eventually balance around 180KW. As time goes on, this fluctuation value will become smaller.

[0035] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A power control system for charging piles based on power line carrier communication, characterized in that, include: A power supply unit used to provide electricity; The charging equipment unit is electrically connected to the power supply unit and is used to charge the vehicle, including several charging piles and a decoder module. The power monitoring unit is used to collect the current and voltage data of the system in real time to calculate the power and generate corresponding digital signals to control the charging equipment unit. It includes a Hall sensor, a three-phase power calculation chip, and a power line carrier modulation module. A power line carrier communication network is used to transmit the digital signal generated by the power monitoring unit to the decoder module; The decoder module can analyze and convert the digital signal into dynamic control commands that are defined differently in response to different overload coefficients, thereby controlling the charging power of the charging pile.

2. The system according to claim 1, characterized in that, It also includes a cloud management platform and the State Grid integrated terminal management system, which can provide dynamic threshold setting, historical data storage and remote policy distribution functions.

3. The system according to claim 1, characterized in that, The physical layer specification of the power line carrier communication network conforms to the IEEE 1901.1 PLC standard, the communication protocol stack conforms to the PLBUS PLC protocol, and advanced technologies such as OFDM modulation and time-frequency domain channel interleaving are used to ensure communication robustness. The supported frequency band range is 2 to 12 MHz, the default operating frequency band is 2.4 to 5.7 MHz, the communication rate is 120 kbps to 1.2 Mbps, and the typical point-to-point communication distance is 200 to 500 meters.

4. A method for controlling the power of a charging pile based on power line carrier communication, implemented by the system according to any one of claims 1 to 3, characterized in that, include: Acquire real-time current and voltage data and calculate real-time power; Based on the real-time power and the preset maximum safe power threshold, the overload factor is determined; The control mechanism is determined based on the overload coefficient, and the digital signal of the control mechanism is transmitted to the decoder module of each charging pile for decoding via power line carrier communication. The decoder module converts the digital signal into dynamic PWM duty cycle control commands corresponding to different overload coefficients to adjust the power of the charging pile.

5. The method according to claim 4, characterized in that, The current and voltage data include the system's total current and total voltage, as well as the current and voltage detected autonomously by each charging pile.

6. The method according to claim 5, characterized in that, The overload factor is the ratio of the real-time power in the system to the maximum safe power threshold. When the overload coefficient is ≥ k1, the first-level control mechanism is activated: that is, the power of the charging pile with power greater than p1 is reduced in steps by gradient G1. When the overload coefficient ≥ k2, a secondary control mechanism is activated: the power of charging piles with power greater than p1 is directly reduced by G. 2； When the overload coefficient is ≥1.0, a three-level control mechanism is activated: charging piles with power p2 < power ≤ p3 will have an additional 20% step power attenuation, while charging piles with power greater than p3 will have their power directly reduced to the minimum value. Among them, k1 <k2<1,p1>p3>p2 。 7. The method according to claim 6, characterized in that, After the control mechanism is implemented, i.e., when the overload coefficient is <k1, the charging pile after the power adjustment gradually restores its power over a period of time to avoid instantaneous overload. The recovery process is controlled by the overload coefficient to determine whether it gradually restores to the maximum output power.

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