An alternating current charging post system

Abstract

The application discloses an alternating current charging pile system, which comprises a power input module, a relay control module, a charging gun interface module, a signal acquisition module and a micro-processing module; the power input module is connected with the relay control module, and the relay control module is connected with the charging gun interface module; the signal acquisition module is connected with the power input module, is used for acquiring alternating current signals output by the power input module, and transmits the acquired alternating current signals to the micro-processing module; the micro-processing module is connected with the signal acquisition module and the relay control module, and generates an electric energy quality alarm signal based on the alternating current signals. The application realizes electric energy quality monitoring and analysis, orderly charging management, monitoring of insulation abnormalities in a vehicle charging process, early reminding of users for maintenance of insulation aging abnormalities of cables and connectors, and avoidance of the risk of electric shock and short circuit.

Description

Technical Field

[0001] This invention relates to the field of charging pile technology, and in particular to an AC charging pile system. Background Technology

[0002] With the promotion and application of new energy vehicles, more and more people are choosing electric vehicles when buying private cars. Their charging locations are mainly in residential areas, and charging time is concentrated at night. When a large number of electric vehicles are charging simultaneously, it poses a challenge to the power safety of residential areas, mainly involving power quality and distribution network capacity issues. When the performance of on-board chargers degrades, it may generate significant harmonics and reactive power, affecting power grid quality. Summary of the Invention

[0003] Based on this, the present invention provides an AC charging pile system that solves the problems of power quality analysis, insufficient distribution network capacity, and leakage current detection.

[0004] This invention provides an AC charging pile system, the system comprising:

[0005] Power input module, relay control module, charging gun interface module, signal acquisition module, and microprocessor module;

[0006] The power input module is connected to the relay control module, and the relay control module is connected to the charging gun interface module;

[0007] The signal acquisition module is connected to the power input module and is used to acquire the AC signal output by the power input module and transmit the acquired AC signal to the microprocessor module.

[0008] The microprocessor module connects the signal acquisition module and the relay control module, and generates a power quality alarm signal based on the AC signal.

[0009] Furthermore, the signal acquisition module includes:

[0010] A voltage signal acquisition module is connected to the power input module and is used to acquire the voltage signal output by the power input module;

[0011] A current signal acquisition module is connected to the power input module and is used to acquire the current signal output by the power input module.

[0012] An analog-to-digital converter module, connected to the voltage acquisition module and the current acquisition module, is used to control the voltage acquisition module to acquire the voltage signal output by the power input module, and the current acquisition module to acquire the current signal output by the power input module; after analog-to-digital conversion of the voltage signal and the current signal, the data is transmitted to the microprocessor module.

[0013] Furthermore, a power quality signal is generated based on the AC signal acquired by the signal acquisition module, specifically as follows:

[0014] The total harmonic content of the AC signal and the flicker value of the phase voltage within a certain period are obtained. If the total harmonic content of the AC signal exceeds the standard limit of the harmonic content of the power grid, or the flicker value of the phase voltage exceeds the standard flicker value limit, a power quality alarm signal is generated.

[0015] Furthermore, the system also includes:

[0016] The control and guidance module is connected to the charging gun interface module and is used to detect the connection status between the charging gun and the device to be charged at the charging gun interface module, generate a connection signal, and transmit the connection signal to the microprocessor module.

[0017] Furthermore, the system also includes:

[0018] A digital communication module, connected to the charging gun interface module, is used to obtain the battery capacity and current power of the device to be charged connected to the charging gun at the charging gun interface module, and transmit it to the microprocessor module.

[0019] A power line carrier module, connected to the microprocessor module, transmits the battery capacity and current power of the device to be charged to the intelligent fusion terminal module;

[0020] The intelligent fusion terminal module is connected to the power input module and is used to obtain the total output power of the power input module, as well as the total electrical capacity and actual total output power of the distribution transformer. It also receives the battery capacity and current charge of the device to be charged. Based on the battery capacity and current charge of the device to be charged, the total output power of the power input module, the total electrical capacity and actual total output power of the distribution transformer, it outputs a charging control signal.

[0021] Furthermore, based on the battery capacity and existing power of the device to be charged, the total output power of the power input module, the total electrical capacity of the distribution transformer, and the actual total output power of the distribution transformer, a charging control signal is output, specifically as follows:

[0022] If the actual total output power of the distribution transformer is greater than the total electrical capacity of the distribution transformer, then determine whether the current power of each device to be charged exceeds the product of the battery capacity and the coefficient of the device to be charged.

[0023] If the current power of the device to be charged is greater than or equal to the product of the battery capacity and coefficient of the device to be charged, a first charging control signal is generated and transmitted to the power input module, so that the power input module stops charging the device to be charged, updates the actual total output power of the distribution transformer and the total output power of the power input module, and determines whether the updated actual total output power of the distribution transformer is greater than the total electrical energy capacity of the distribution transformer.

[0024] If the current charge of the device to be charged is less than the product of the battery capacity and the coefficient, a second charging control signal is generated; the second charging control signal is the total output power of the power input module multiplied by a derating factor, wherein the derating factor is:

[0025]

[0026] Furthermore, the system also includes:

[0027] An AC / DC leakage current detection module is connected to the power input module and is used to detect the current signal of the power input module. The detected current signal is transmitted to the microprocessor module, which generates a leakage current warning signal based on the detected current signal.

[0028] Furthermore, the microprocessor module generates a leakage current warning signal based on the detected current signal, specifically as follows:

[0029] If the detected current signal is greater than the preset threshold, a leakage current warning signal is generated.

[0030] Furthermore, the AC / DC leakage current detection module includes:

[0031] A current transformer, the primary side of which is connected to the power input module;

[0032] The filtering module performs low-pass filtering on the current signal of the secondary side of the transformer to obtain a voltage signal proportional to the primary side current signal, and transmits it to the bias module.

[0033] The bias module biases the voltage signal and then transmits it to the microprocessor module.

[0034] Furthermore, the system also includes:

[0035] A network communication module, connected to the microprocessor module, is used to communicate with the charging operator platform.

[0036] This invention provides an AC charging pile system that collects voltage and current signals in real time through a signal acquisition module. Based on the voltage and current signals collected by the signal acquisition module, a microprocessor module obtains data such as the effective value of voltage and current, harmonics, power factor, and grid frequency. This enables power quality monitoring and analysis, effectively monitors the operation of the on-board charger, promptly detects anomalies, and reminds users to carry out maintenance, thus avoiding impact on the power grid. It ensures that the power supply quality of the grid is not affected when a large number of electric vehicles are charging, which is more in line with the needs of the development of new energy electric vehicles.

[0037] Data interaction between the charging device and the intelligent distribution transformer fusion terminal is achieved using a power line carrier module. Vehicle charging information can be sent to the fusion terminal, which then generates scheduling instructions based on the current charging pile, distribution transformer, and vehicle charging information. The charging pile receives these instructions from the intelligent distribution transformer fusion terminal, enabling orderly charging management. Utilizing existing intelligent distribution transformer interaction terminals and achieving information exchange via power line carrier communication facilitates the upgrading and transformation of orderly charging functions, reduces on-site construction difficulties, and enables power grid companies to effectively manage the load of charging equipment. While ensuring power safety, this maximizes the utilization rate of distribution transformer equipment and facilitates the fulfillment of the rigid charging needs of residential communities with tight power loads.

[0038] It integrates leakage current detection circuits for both AC and DC leakage current, enabling it to monitor insulation abnormalities during vehicle charging. It can proactively alert users to insulation aging abnormalities in cables and connectors (such as insulation failures caused by aging internal vehicle cables or damaged battery packs), preventing the risk of electric shock and short circuits. Compared to general Type A leakage protection, it can detect internal DC leakage during vehicle charging, providing multi-level monitoring of the vehicle's internal insulation and the on-board charger's operating condition, thus more effectively ensuring the safety of electric vehicle charging and use. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of an AC charging pile system provided in the first embodiment of the present invention;

[0041] Figure 2 This is a schematic diagram of another AC charging pile system provided in the first embodiment of the present invention;

[0042] Figure 3This is a schematic diagram of another AC charging pile system provided in the first embodiment of the present invention;

[0043] Figure 4 This is a schematic diagram of an AC charging pile system provided in the second embodiment of the present invention;

[0044] Figure 5 A schematic diagram of an AC charging pile system is provided for the third embodiment of the present invention;

[0045] Figure 6 for Figure 5 A schematic diagram of an AC / DC leakage current detection module circuit.

[0046] Figure 7 A schematic diagram of another AC charging pile system provided for the fourth embodiment. Detailed Implementation

[0047] Unless otherwise defined, 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 application pertains; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application, are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0048] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0049] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0050] In the following description, suffixes such as “module,” “part,” or “unit” used to denote elements are used only for the purposes of this application and have no specific meaning in themselves.

[0051] Currently, most AC charging piles in the industry meet the requirements of the national standard GB / T18487, possessing only general charging functions but lacking power quality analysis and orderly charging capabilities. For large-scale public charging stations, independent power quality analyzers are installed for power quality monitoring. However, due to high costs and the inability to pinpoint specific fault locations, power quality analysis devices are rarely installed in residential charging areas. Existing AC charging pile solutions typically use electricity meters or ordinary metering chips to measure voltage and current signals, which cannot perform high-speed real-time sampling, thus failing to acquire data such as harmonics and voltage flicker, and therefore cannot perform power quality analysis. When a large number of electric vehicles are charging simultaneously, if the performance of the vehicle's on-board charger degrades, it can generate significant harmonics that affect grid quality.

[0052] like Figure 1 The diagram shown is a schematic of an AC charging pile system provided by an embodiment of the present invention. The system includes: a power input module 1, a relay control module 2, a charging gun interface module 3, a signal acquisition module 4, and a microprocessor module 5.

[0053] The power input module 1 is connected to the relay control module 2, and the relay control module 2 is connected to the charging gun interface module 3. The signal acquisition module 4 is connected to the power input module 1 and is used to acquire the AC signal output by the power input module 1 and transmit the acquired AC signal to the microprocessor module 5. The microprocessor module 5 is connected to the signal acquisition module 4 and the relay control module 2, and generates a power quality alarm signal based on the AC signal. Specifically, it acquires the total harmonic content of the AC signal and the flicker value of the phase voltage within a certain period. If the total harmonic content of the AC signal exceeds the standard limit of the power grid harmonic content, or the flicker value of the phase voltage exceeds the standard flicker value limit, a power quality alarm signal is generated.

[0054] In this embodiment, the AC charging pile system can achieve a maximum output power of 22kW, is a three-phase four-wire power supply, and is compatible with single-phase power. When charging is required, the relay control module 2 closes, and the charging gun of the charging gun interface module 4 connects to the device to be charged for charging. At the same time, the signal acquisition module 4 acquires the AC signal output by the power input module 1. In this embodiment, the signal acquisition module 4 samples 128 points every 20ms cycle and transmits the acquired AC signal to the microprocessor module 5. The microprocessor module 5 obtains the harmonic content of each phase from the 2nd to the 50th order and the total harmonic content of the three phases through Fourier series decomposition. According to industry standards, the harmonic content of the low-voltage power grid shall not exceed 5%. If the total harmonic content of the three-phase voltage exceeds the standard limit, a power quality alarm signal is generated.

[0055] By performing FFT operations on the sampling points, the phase and frequency of each phase voltage and current can be obtained, and the power factor can be calculated from this. The root mean square of each voltage sampling point is calculated for each cycle to obtain the effective value of each phase voltage. The effective values ​​collected within 1 minute are sorted and discretely analyzed to obtain the voltage flicker value, which is compared with the flicker value required by the standard. When the limit is exceeded, a power quality alarm signal is generated.

[0056] The FFT operation uses the FFT function from the ARM DSP library, employing single-precision floating-point complex number arithmetic. The function prototype is as follows:

[0057] void arm_cfft_f32(const arm_cfft_instance_f32*S, float32_t*p1, uint8_tifftFlag, uint8_t bitReverseFlag);

[0058] Function parameter description: The first parameter, arm_cfft_instance_f32*S, is a pre-packaged FFT floating-point instantiation that supports FFT conversion from 16 to 4096 points. Our solution uses &arm_cfft_sR_f32_len128 to implement 128-point FFT operations.

[0059] The second parameter, *p1, is a pointer address that points to the sample data array, which is the converted floating-point data with real and imaginary parts after AD sampling.

[0060] The third parameter, ifftFlag, specifies whether the function performs an inverse transform (ifftFlag = 1) or a forward transform (ifftFlag = 0). This scheme uses the forward transform to obtain frequency domain data.

[0061] The fourth parameter, bitReverseFlag, specifies whether to perform a bit-reversal transformation on the result. This scheme uses a bit-reversal transformation to achieve sequential incrementing of frequency domain data.

[0062] The function call is as follows:

[0063] arm_cfft_f32(&arm_cfft_sR_f32_len128,AcSample_buf_float,0,1);

[0064] Then, the phase is calculated based on the output of the FFT operation as follows:

[0065] iAngle=180.0*10 / 3.1415926*atan2f(AcSample_buf_float[1].im,AcSample_buf_float[1].re);

[0066] The principle is to calculate the corresponding phase angle in the coordinate system based on the real and imaginary parts of the fundamental complex number, and then convert it into a radian value. Using this algorithm, the phase of the three-phase voltage and current can be obtained. The voltage-current angle can be calculated using the phase difference between voltage and current, and the cosine of the voltage-current angle is the power factor of the power grid.

[0067] For continuous A-phase voltage sampling points, the upward zero-crossing points are statistically analyzed. The time interval between two upward zero-crossing points is the voltage period. The frequency of the power grid can be obtained by taking the reciprocal of the period.

[0068] like Figure 2 The diagram shows an AC charging pile system according to an embodiment of the present invention. The signal acquisition module 4 includes: a voltage signal acquisition module 41 connected to the power input module 1, used to acquire the voltage signal output by the power input module 1; a current signal acquisition module 42 connected to the power input module 1, used to acquire the current signal output by the power input module 1; and an analog-to-digital conversion module 43 connected to the voltage acquisition module 41 and the current acquisition module 42, used to control the voltage acquisition module 41 to acquire the voltage signal output by the power input module 1, and the current acquisition module 42 to acquire the current signal output by the power input module 1; the voltage signal and the current signal are converted from analog to digital and then transmitted to the microprocessor module 5.

[0069] In this embodiment, to meet the power quality analysis function, the analog-to-digital conversion module 43 uses the TI ADS1178 AD conversion chip, which integrates an 8-channel 16-bit synchronous sampling ADC with a sampling rate of up to 52kSPS. The voltage signal acquisition module 41 uses three current-type voltage transformers, and the current signal acquisition module 42 uses three current transformers. The microprocessor module 5 uses a NUC980DK61Y processor. The secondary signals of the transformers are connected to the differential input of the ADS1178, and the primary signals of the transformers are connected to the power input module 1. The ADS1178 is connected to the NUC980DK61Y processor via an SPI interface.

[0070] Furthermore, such as Figure 3 The diagram shown is an AC charging pile system provided by an embodiment of the present invention. The system further includes: a control and guidance module 6, which is connected to the charging gun interface module 3, for detecting the connection status between the charging gun and the device to be charged at the charging gun interface module, generating a connection signal, and transmitting the connection signal to the microprocessor module 5.

[0071] Currently, due to the lack of information linkage between charging piles and transformer monitoring, there is no basis for power control of charging piles. Generally, the remaining transformer capacity is roughly estimated based on historical experience data, and charging piles exceeding the power limit are shut down or their installation prohibited. For example... Figure 4 The diagram shows an AC charging pile system according to an embodiment of the present invention. The system further includes a digital communication module 7 connected to the charging gun interface module 3, used to acquire the battery capacity and current power of the device to be charged connected to the charging gun at the charging gun interface module 3, and transmit it to the microprocessor module 5; a power line carrier module 8 connected to the microprocessor module 5, which transmits the battery capacity and current power of the device to be charged to the intelligent fusion terminal module 9; and an intelligent fusion terminal module 9 connected to the power input module 1, used to acquire the total output power of the power input module 1, and simultaneously acquire the total electrical capacity and actual total output power of the distribution transformer, and receive the battery capacity and current power of the device to be charged; based on the battery capacity and current power of the device to be charged, the system transmits the battery capacity and current power of the device to be charged, the total output power of the power input module, the total electrical capacity and actual total output power of the distribution transformer, and the actual total output power of the distribution transformer, the system transmits the battery capacity and current power of the device to be charged to the intelligent fusion terminal module 9. The actual total output power of the distribution transformer is used to output a charging control signal. Specifically, if the actual total output power of the distribution transformer is greater than the total electrical capacity of the distribution transformer, it is determined whether the current power of each device to be charged exceeds the product of the battery capacity and coefficient of the device to be charged. If the current power of the device to be charged is greater than or equal to the product of the battery capacity and coefficient of the device to be charged, a first charging control signal is generated and transmitted to the power input module, causing the power input module to stop charging the device to be charged, and update the actual total output power of the distribution transformer and the total output power of the power input module, and determine whether the updated actual total output power of the distribution transformer is greater than the total electrical capacity of the distribution transformer. If the current power of the device to be charged is less than the product of the battery capacity and coefficient of the device to be charged, a second charging control signal is generated. The second charging control signal is the total output power of the power input module multiplied by a derating factor, wherein the derating factor is:

[0072]

[0073] In this embodiment, the power line carrier module 8 is connected to the microprocessor module 5 via a UART interface. The power input module 1 and the intelligent fusion terminal module 9 use AC power lines to achieve information interaction between the modules, saving communication cables and facilitating on-site installation. The technical parameters of the power line carrier module 8 comply with the technical specifications formulated by the State Grid and China Southern Power Grid, support the enhanced modulation mode of 256QAM, and have strong anti-interference capabilities.

[0074] The digital communication module 7 obtains the battery capacity and the existing power of the device to be charged connected to the charging gun at the charging gun interface module 3, and transmits them to the microprocessing module 5; and transmits them to the power carrier module 8 through the microprocessing module 5. The power carrier module 8 transmits the battery capacity and the existing power of the device to be charged to the intelligent fusion terminal module 9. At the same time, the intelligent fusion terminal module 9 collects the total capacity P0 of the distribution transformer, the current actual output total power P1 of the distribution transformer, and the total power P2 output by the power input module, and outputs a charging control signal based on the battery capacity and the existing power of the device to be charged, the total power P2 output by the power input module, the total electrical energy capacity P0 of the distribution transformer, and the current actual output total power P1 of the distribution transformer. The specific steps are as follows:

[0075] S1: Determine the relationship between the actual output total power P1 of the distribution transformer and the total electrical energy capacity P0 of the distribution transformer;

[0076] If P1 < P0, the actual power P1 of the distribution transformer does not exceed the total capacity P0 of the distribution transformer, and the charging pile system can output according to the actual demand without power regulation, and the derating factor K is 1.0.

[0077] If P1 ≥ P0, the actual output power P1 of the distribution transformer exceeds the total capacity P0 of the distribution transformer, and it is necessary to reduce the total power P2 output by the charging pile system and enter S2 for execution.

[0078] S2: Determine whether the existing power of each device to be charged exceeds the product of the battery capacity of the device to be charged and the coefficient;

[0079] If the existing power of the device to be charged is greater than or equal to the product of the battery capacity of the device to be charged and the coefficient, enter S3 for execution;

[0080] If the existing power of the device to be charged is less than the product of the battery capacity of the device to be charged and the coefficient, enter S4 for execution;

[0081] If the existing power of the existing device to be charged is greater than or equal to 90% of the battery capacity of the device to be charged, enter S3 for execution. If the existing power of the existing device to be charged is less than 90% of the battery capacity of the device to be charged, enter S4 for execution. Among them, the coefficient can be adjusted according to requirements.

[0082] S3: Generate a first charging control signal and transmit it to the power input module 1 to stop charging the device to be charged; then update the total power P2 output by the power input module and the current actual output total power P1 of the distribution transformer, and enter S1 for execution.

[0083] S4: Generate a second charging control signal; the second charging control signal is the total output power P2 of the power input module multiplied by a derating factor K, wherein the derating factor K is:

[0084] K = 1 - (P1 - P0) / P2 (When K < 0, K = 0)

[0085] When the power input module receives the derating factor K from the intelligent fusion terminal, it multiplies the actual power P2 of the current power input module 1 by the factor K to determine the power output that needs adjustment. It then calculates the required current value based on the current voltage and, according to the relationship between current and PWM duty cycle (referencing the requirements in standard GB / T18487.1-2015 Electric Vehicle Conductive Charging System Part 1: General Requirements), determines the duty cycle value. Based on the calculated duty cycle, it outputs a PWM signal, which can regulate the vehicle to charge at the desired power. This achieves orderly charging and prevents the distribution transformer from being overloaded for extended periods.

[0086] Furthermore, current AC charging stations on the market only have Type A leakage protection and cannot detect DC leakage signals. If DC leakage occurs, it could endanger personal safety. Figure 5 The diagram shows an AC charging pile system. The system further includes an AC / DC leakage current detection module 10, which is connected to the power input module 1 and is used to detect the current signal of the power input module 1. The detected current signal is transmitted to the microprocessor module 5. The microprocessor module 5 generates a leakage current warning signal based on the detected current signal. Specifically, if the detected current signal is greater than a preset threshold, a leakage current warning signal is generated.

[0087] like Figure 6 The diagram shows a circuit diagram of an AC / DC leakage current detection module, including: a current transformer T1, the primary side of which is connected to the power input module 1; and a filtering module 101, which performs low-pass filtering on the current signal of the secondary side of the current transformer to obtain a voltage signal proportional to the primary side current signal, and transmits it to the bias module 102.

[0088] The filtering module 101 includes a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a PMOS transistor Q1, an NMOS transistor Q2, a first amplifier U1A, a second amplifier U1B, and a third amplifier U2B. One side of the secondary winding of the current transformer (T1 stage) is connected to one end of the fifth resistor R5, one end of the fourth resistor R4, the source of the PMOS transistor, and the source of the NMOS transistor. The other end of the fifth resistor R5 is connected to one end of the sixth resistor R6, and the other end of the sixth resistor R6 is grounded. The other end of the fourth resistor R4 is connected to one end of the third resistor R3, and the other end of the third resistor R3 is connected to the output terminal of the second amplifier U1B. The negative terminal of the second amplifier U1B is connected to one end of the sixth resistor R6. The positive terminal of amplifier U1B is connected to the bias module; the drain of the PMOS transistor is input with a preset voltage, and the gate of the PMOS transistor is connected to the output terminal of the first amplifier; the source of the PMOS transistor is connected to the source of the NMOS transistor, the drain of the NMOS transistor is input with a preset voltage, and the gate of the NMOS transistor is connected to the output terminal of the third amplifier U2B; the negative terminal of the third amplifier U2B is connected between the third resistor R3 and the fourth resistor R4, the positive terminal of the third amplifier U2B is connected to one end of the first resistor R1 and one end of the second resistor R2, and the other end of the second resistor R2 is grounded; the other end of the first resistor R1 is connected to the output terminal of the first amplifier U1A, the negative terminal of the first amplifier U1A is connected to the bias module, and the positive terminal of the first amplifier U1A is connected to one end of the sixth resistor.

[0089] A high-frequency oscillation circuit is generated using operational amplifiers U1A, U1B, and U2B. The current transformer T1 is made of cobalt-based amorphous material with high magnetic permeability. A small current signal passing through the primary side of the current transformer is induced onto the secondary side coil by an alternating magnetic field. A second-order low-pass Sallen-Key filter composed of U2C is designed to perform low-pass filtering on the secondary side signal, resulting in a voltage signal proportional to the primary side current signal, which is then transmitted to the bias module.

[0090] The bias module 102 biases the voltage signal and then transmits it to the microprocessor module 5. The bias module includes a seventh resistor R7, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, a fourth amplifier U2C, and a fifth amplifier U2D. One end of the eleventh resistor R11 is connected to the positive terminal of the first amplifier U1A; one end of the eleventh resistor R11 is connected to the negative terminal of the second amplifier U1B, and the other end of the eleventh resistor R11 is grounded. One end of the eighth resistor R8 is connected to one end of the eleventh resistor R11, and the other end of the eighth resistor R8 is connected to one end of the first capacitor C1 and one end of the ninth resistor R9. The other end of the first capacitor C1 is connected to one end of the tenth resistor R10; the other end of the ninth resistor R9 is connected to the fourth amplifier U2C. The positive terminal of the second capacitor C2 is connected, with one end connected between the ninth resistor R9 and the fourth amplifier U2C, and the other end grounded. The negative terminal of the fourth amplifier U2C is connected to one end of the thirteenth resistor R13, and the other end of the thirteenth resistor R13 is grounded. One end of the twelfth resistor R12 is connected to one end of the thirteenth resistor R13, and the other end of the twelfth resistor R12 is connected to one end of the tenth resistor R10. The output terminal of the fourth amplifier U2C is connected to one end of the tenth resistor R10. The other end of the tenth resistor R10 is connected to the positive terminal of the fifth amplifier U2D. One end of the seventh resistor R7 is connected between the tenth resistor R10 and the fifth amplifier U2D, and the other end of the seventh resistor R7 is input with a bias voltage V. RET The negative terminal and output terminal of the fifth amplifier U2D are connected to the microprocessor module.

[0091] In this embodiment, the fifth amplifier U2D is connected to the A / D conversion interface of the microprocessor module, and the signal is applied V using the seventh resistor R7 and the tenth resistor R10. REF The voltage is biased and then connected to the A / D conversion interface of the microprocessor module 5 via the operational amplifier U2D voltage follower. The A / D conversion result is converted into a current signal, which is compared with a preset threshold. If the current exceeds the leakage current threshold, the microprocessor module generates a leakage current warning signal to control the relay control module to trip, thus achieving leakage current protection.

[0092] like Figure 7 The diagram shown is a schematic representation of an AC charging pile system according to an embodiment of the present invention. The system further includes a network communication module 11, connected to the microprocessor module 5, for communicating with a charging operator platform. The network communication module 11 can communicate with the charging operator platform and transmit the signals and data generated by the microprocessor module 5 to the charging operator platform.

[0093] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the above methods. Any references to memory, storage, databases, or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory can include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), or flash memory. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), dual data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link DRAM (SLDRAM), Rambus direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM), etc.

[0094] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is used as an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above.

[0095] The above-described embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention, and should all be included within the protection scope of the present invention.

Claims

1. An AC charging pile system, characterized in that, The system includes: Power input module, relay control module, charging gun interface module, signal acquisition module, and microprocessor module; The power input module is connected to the relay control module, and the relay control module is connected to the charging gun interface module; The signal acquisition module is connected to the power input module and is used to acquire the AC signal output by the power input module and transmit the acquired AC signal to the microprocessor module. The microprocessor module connects the signal acquisition module and the relay control module, and generates a power quality alarm signal based on the AC signal. A digital communication module, connected to the charging gun interface module, is used to obtain the battery capacity and current power of the device to be charged connected to the charging gun at the charging gun interface module, and transmit it to the microprocessor module. A power line carrier module, connected to the microprocessor module, transmits the battery capacity and current power of the device to be charged to the intelligent fusion terminal module; The intelligent fusion terminal module is connected to the power input module and is used to obtain the total output power of the power input module, as well as the total electrical capacity and actual total output power of the distribution transformer. It also receives the battery capacity and current charge of the device to be charged. Based on the battery capacity and current charge of the device to be charged, the total output power of the power input module, the total electrical capacity and actual total output power of the distribution transformer, it outputs a charging control signal. Based on the battery capacity and current charge of the device to be charged, the total output power of the power input module, the total electrical capacity of the distribution transformer, and the actual total output power of the distribution transformer, a charging control signal is output, specifically: If the actual total output power of the distribution transformer is greater than the total electrical capacity of the distribution transformer, then determine whether the current power of each device to be charged exceeds the product of the battery capacity and the coefficient of the device to be charged. If the current power of the device to be charged is greater than or equal to the product of the battery capacity and coefficient of the device to be charged, a first charging control signal is generated and transmitted to the power input module, so that the power input module stops charging the device to be charged, updates the actual total output power of the distribution transformer and the total output power of the power input module, and determines whether the updated actual total output power of the distribution transformer is greater than the total electrical energy capacity of the distribution transformer. If the current charge of the device to be charged is less than the product of the battery capacity and the coefficient, a second charging control signal is generated; the second charging control signal is the total output power of the power input module multiplied by a derating factor, wherein the derating factor is:

2. The AC charging pile system according to claim 1, characterized in that, The signal acquisition module includes: A voltage signal acquisition module is connected to the power input module and is used to acquire the voltage signal output by the power input module; A current signal acquisition module is connected to the power input module and is used to acquire the current signal output by the power input module. An analog-to-digital converter module, connected to the voltage signal acquisition module and the current signal acquisition module, is used to control the voltage signal acquisition module to acquire the voltage signal output by the power input module, and the current signal acquisition module to acquire the current signal output by the power input module; after analog-to-digital conversion of the voltage signal and the current signal, the data is transmitted to the microprocessor module.

3. The AC charging pile system according to claim 1, characterized in that, The power quality signal is generated based on the AC signal acquired by the signal acquisition module, specifically as follows: The total harmonic content of the AC signal and the flicker value of the phase voltage within a certain period are obtained. If the total harmonic content of the AC signal exceeds the standard limit of the harmonic content of the power grid, or the flicker value of the phase voltage exceeds the standard flicker value limit, a power quality alarm signal is generated.

4. The AC charging pile system according to claim 1, characterized in that, The system also includes: The control and guidance module is connected to the charging gun interface module and is used to detect the connection status between the charging gun and the device to be charged at the charging gun interface module, generate a connection signal, and transmit the connection signal to the microprocessor module.

5. An AC charging pile system according to claim 1, characterized in that, The system also includes: An AC / DC leakage current detection module is connected to the power input module and is used to detect the current signal of the power input module. The detected current signal is transmitted to the microprocessor module, which generates a leakage current warning signal based on the detected current signal.

6. An AC charging pile system according to claim 5, characterized in that, The microprocessor module generates a leakage current warning signal based on the detected current signal, specifically as follows: If the detected current signal is greater than the preset threshold, a leakage current warning signal is generated.

7. An AC charging pile system according to claim 5, characterized in that, The AC / DC leakage current detection module includes: A current transformer, the primary side of which is connected to the power input module; The filtering module performs low-pass filtering on the current signal of the secondary side of the transformer to obtain a voltage signal proportional to the primary side current signal, and transmits it to the bias module. The bias module biases the voltage signal and then transmits it to the microprocessor module.

8. An AC charging pile system according to any one of claims 1-7, characterized in that, The system also includes: A network communication module, connected to the microprocessor module, is used to communicate with the charging operator platform.

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