Charging pile power control method and control system based on PWM signal control

Abstract

The invention discloses a charging pile power control method and system based on PWM signal control, and belongs to the technical field of charging power intelligent control, and the method comprises the steps: enabling two ends of a controller to be connected with a vehicle-mounted charging port and a charging gun head port of a charging pile, and executing the step if the power supply type of the charging gun head port is alternating current; the charging power of the charging gun head port is obtained based on the charging plan, the charging power is adjusted in real time based on the PWM signal to generate stable power, and the stable power is sent to the vehicle-mounted charging port; the charging power, the stable power and the PWM signal are collected in real time, a data set is generated, and the mathematical analysis model outputs a prediction result of the stable power in a future preset period based on the data set; and generating an optimized prediction result corresponding to the prediction result based on the prediction error, and adjusting the charging plan to generate a recommendation plan to complete the charging demand. According to the invention, the intelligence and stability of power control during charging of the electric vehicle can be improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of intelligent charging power control, and in particular relates to a charging pile power control method and control system based on PWM signal control. Background Art

[0002] With the popularity of electric vehicles, charging efficiency and power control of charging piles have become key technical issues. Traditional charging piles use PWM signals (Pulse Width Modulation) with fixed frequency and duty cycle to control the charging process, but this method is difficult to adapt to the dynamic changes of battery status and grid conditions, resulting in low charging efficiency and possible damage to the battery. Therefore, it is necessary to optimize the charging process in real time to improve charging efficiency and reduce energy loss.

[0003] Similar prior art includes a Chinese patent application with publication number CN117335669A, which discloses a bidirectional power converter and a control method thereof, a charging facility and a vehicle. According to the bidirectional power converter of the application, it includes a first conversion module, a second conversion module, a switch control signal generation module and a charge and discharge switching module. The first and second conversion modules each include a switch for power conversion. The switch control signal generation module is connected to each switch and includes a plurality of delay units and a plurality of reverse units. The switch control signal generation module receives a pulse width modulation PWM signal, and enables the PWM signal to generate a plurality of switch control signals each having an expected waveform to control the switches in the first conversion module and the second conversion module via a plurality of delay units and a plurality of reverse units. The charge and discharge switching module exchanges the switch control signals of the first conversion module and the second conversion module in response to the charge and discharge switching control signal to realize charge and discharge switching. There is also a Chinese patent application with publication number CN106712471A, which provides a PWM power control device, including: a conditioning unit, suitable for converting a pulse width modulation source signal into a DC signal; a drive signal parameter adjustment unit, connected to the output end of the conditioning unit, suitable for comparing a triangular wave signal with a DC signal to generate a reference pulse signal that meets a preset working frequency; a power drive unit, connected to the output end of the drive signal parameter adjustment unit, suitable for driving a switch tube according to a reference pulse signal to output a power signal. Compared with the same power control device, under the premise of unchanged system performance, the input frequency of the PWM signal is reduced, and at the same time, the duty cycle control accuracy of the PWM signal is improved; the size of the energy storage element is reduced, cost is saved, and its working efficiency is improved.

[0004] However, in the above-mentioned prior art, only the PWM signal is used inside the charging facility to realize the charging and discharging switching, which has a hysteresis in the power regulation control and affects the battery life of the charging facility. Only the duty cycle of the PWM signal is accurately controlled, and the power change trend is not predicted. Summary of the invention

[0005] In order to solve the above problems, the present invention provides a charging pile power control method and control system based on PWM signal control to solve the problems in the prior art.

[0006] In order to achieve the above-mentioned invention object, the present invention proposes a charging pile power control method based on PWM signal control, comprising:

[0007] SS1: Connect the two ends of the controller to the vehicle charging port and the charging gun head port of the charging pile respectively. If the power supply type of the charging gun head port is AC, execute S2;

[0008] S2: The controller obtains a charging plan based on a preset communication mode, obtains the charging power of the charging gun head port based on the charging plan, receives a PWM signal, adjusts the charging power in real time based on the PWM signal to generate stable power, and sends the stable power to the vehicle-mounted charging port;

[0009] S3: collecting the charging power, the corresponding stable power and the PWM signal in real time based on time characteristics, generating a data set, and constructing a mathematical analysis model, wherein the mathematical analysis model outputs a prediction result of the stable power within a future preset period based on the data set;

[0010] S4: Obtain the prediction error of the mathematical analysis model, generate an optimized prediction result corresponding to the prediction result based on the prediction error, adjust the charging plan based on the optimized prediction result to generate a recommended plan to meet the charging requirements.

[0011] Further, the stable power is generated based on the following steps:

[0012] Within a preset time range, the controller is started, wherein the controller includes a PWM analysis unit, an MCU main control unit and a PWM sending unit;

[0013] The PWM analysis unit receives and analyzes the PWM signal sent by the charging pile;

[0014] The MCU main control unit receives the charging plan, generates a planned PWM signal based on the charging plan, compares the duty cycle between the PWM signal and the planned PWM signal, and if the duty cycle of the planned PWM signal is smaller than the duty cycle of the PWM signal, sends the duty cycle of the planned PWM signal to the PWM sending unit;

[0015] The PWM sending unit receives the planned PWM signal sent by the MCU main control unit, generates a modulation signal based on the duty cycle of the planned PWM signal, and regulates the charging power to the stable power based on the modulation signal.

[0016] Further, the modulation signal is generated based on the following steps:

[0017] Obtaining a voltage target value of the vehicle-mounted charging port, obtaining an input voltage waveform corresponding to the charging power, and obtaining an amplitude difference between the voltage target value and the input voltage waveform based on a timestamp;

[0018] Locate the half-cycle interval of the input voltage waveform, input the planned PWM signal within the half-cycle interval, correct the input voltage waveform based on the adjustment amount of the duty cycle of the planned PWM signal, until the amplitude difference at the current timestamp belongs to the preset difference interval, and set the planned PWM signal corresponding to the adjusted duty cycle as the modulation signal.

[0019] Furthermore, the step of correcting the input voltage waveform based on the adjustment amount of the duty cycle of the planned PWM signal comprises the following steps:

[0020] When starting the controller, the duty cycle of the received PWM signal should be greater than a first preset value (90%), and the difference between the duty cycle and the first preset value is obtained and set as the adjustment amount;

[0021] The duty cycle D of the planned PWM signal is generated based on a first formula, wherein the first formula is: Wherein, I is the maximum charging current corresponding to the charging plan, and α and β are reference coefficients;

[0022] The duty cycle of the planned PWM signal is adjusted to be reduced in sequence based on the adjustment amount to generate a new duty cycle, and the new duty cycle is greater than a second preset value, and the modulation signal is generated based on the new duty cycle. The modulation signal corrects the input voltage waveform based on a filter, wherein the second preset value is less than the first preset value.

[0023] Furthermore, the mathematical analysis model is constructed based on the following steps:

[0024] The performance parameter data of the vehicle charging port corresponding to the time feature is obtained based on the preset tag, the adjustment square wave waveform corresponding to the PWM signal is obtained based on the signal change trend corresponding to the charging power and the stable power, the charging power in the data set and the charging time in the charging plan are set as input variables, the adjustment square wave waveform is set as the target variable, and the performance parameter data is set as the intermediate variable. The mathematical analysis model is constructed based on the target variable, the input variable and the intermediate variable, wherein the adjustment square wave waveform refers to the square wave waveform corresponding to the modulation signal generated in real time after the controller is started.

[0025] Furthermore, the prediction result of the mathematical analysis model outputting the stable power in a future preset period based on the data set includes the following steps:

[0026] Inputting the regulated square wave waveform into the mathematical analysis model, the mathematical analysis model generates a corresponding predicted PWM signal within a future preset period based on all the signal change trends and the intermediate variables;

[0027] Establishing a neural network prediction model, wherein the neural network model is trained based on the performance parameter data and outputs a prediction result of the performance parameter within a future preset period;

[0028] The mathematical analysis model predicts and generates a change value of the stable power within a future preset period based on the predicted PWM signal and the performance parameter prediction result, and sets the change value as the prediction result.

[0029] Further, adjusting the charging plan based on the prediction result to generate a recommended plan includes the following steps:

[0030] Acquire the actual duty cycle of the regulated square wave waveform in a future preset period in real time, calculate the root mean square error between the actual duty cycle and the duty cycle corresponding to the predicted PWM signal, and set it as the predicted error;

[0031] adjusting the parameters of the mathematical analysis model based on the prediction error, and outputting the optimized PWM signal corresponding to the predicted PWM signal and the optimized prediction result corresponding to the prediction result;

[0032] The charging plan also includes the voltage phase of the charging gun head port, the voltage phase is monitored based on the duty cycle of the optimized PWM signal, and the time interval corresponding to the charging duration is adjusted based on the optimization prediction result, and the adjusted charging plan is set as the recommended plan.

[0033] Furthermore, the communication mode is set to a dual-mode communication mode.

[0034] The present invention also provides a charging pile power control system based on PWM signal control, which is used to implement the above-mentioned charging pile power control method based on PWM signal control. The system mainly includes:

[0035] Connect the module to connect the two ends of the controller to the vehicle charging port and the charging gun head port of the charging pile respectively. If the power supply type of the charging gun head port is AC, perform this step;

[0036] A power control module, wherein the controller obtains a charging plan based on a preset communication mode, obtains the charging power of the charging gun head port based on the charging plan, receives a PWM signal, adjusts the charging power in real time based on the PWM signal to generate stable power, and sends the stable power to the vehicle-mounted charging port;

[0037] An analysis and prediction module collects the charging power, the corresponding stable power and the PWM signal in real time based on time characteristics, generates a data set, and constructs a mathematical analysis model, wherein the mathematical analysis model outputs a prediction result of the stable power within a future preset period based on the data set;

[0038] The plan adjustment module obtains the prediction error of the mathematical analysis model, generates an optimized prediction result corresponding to the prediction result based on the prediction error, and adjusts the charging plan based on the optimized prediction result to generate a recommended plan to meet the charging demand.

[0039] Compared with the prior art, the beneficial effects of the present invention are at least as follows:

[0040] The present invention firstly intercepts the PWM signal emitted by the charging gun head port by installing a controller, and generates a modulation signal by adjusting the duty cycle of the PWM signal through receiving the charging plan to control the charging power, which can reduce the loss caused by the charging power at the vehicle charging port. Then, the adjustment amount is set by the duty cycle of the PWM signal to improve the accuracy of the input voltage waveform, and avoid the situation where the charging power is too high or too low, which reduces the power control efficiency. Finally, by constructing a mathematical analysis model to analyze and predict the data set, the correlation between the performance parameter data and the charging power and PWM signal is improved, and a recommended plan is generated, which can improve the intelligence and stability of electric vehicle charging.

[0041] The present invention also improves the timeliness and accuracy of power control by combining the prediction of stable power with the PWM signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 This is a flowchart of a charging pile power control method based on PWM signal control according to the present invention;

[0043] Figure 2 It is a schematic diagram of the working principle of the controller in the present invention;

[0044] Figure 3 This is a structural diagram of a charging pile power control system based on PWM signal control in the present invention. DETAILED DESCRIPTION

[0045] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0046] It is understood that the terms "first", "second", etc. used in this application may be used herein to describe various elements, but unless otherwise specified, these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first xx script may be referred to as a second xx script, and similarly, a second xx script may be referred to as a first xx script.

[0047] like Figure 1 As shown, a charging pile power control method based on PWM signal control includes:

[0048] S1: Connect the two ends of the controller to the vehicle charging port and the charging gun head port of the charging pile respectively. If the power supply type of the charging gun head port is AC, execute S2.

[0049] Specifically, the present invention improves the charging power stability of a private charging pile by "grafting PWM signals" through a controller. In this embodiment, the charging gun head port is the charging gun port of the charging pile, and the power supply type refers to the power supply mode corresponding to the charging pile, including AC type and DC type, where AC belongs to the AC type. In the present invention, the controller refers to a power controller for an AC charging pile, and its use method is: first plug the power controller into the on-board charging port on the vehicle, and then plug the charging gun of the charging gun head port into the controller.

[0050] S2: The controller obtains the charging plan based on the preset communication mode, obtains the charging power of the charging gun head port based on the charging plan, receives the PWM signal, adjusts the charging power in real time based on the PWM signal to generate stable power, and sends it to the vehicle charging port.

[0051] Specifically, in this embodiment, it is necessary to timely and accurately obtain the data collected by various sensors through a preset communication method. The charging plan refers to various data information corresponding to the charging demand, including but not limited to the information and voltage phase of the charging gun head port, and the charging time and charging duration corresponding to the set charging instruction. Charging power refers to the rate at which electric energy is transferred from the power source (such as the charging gun head port) to the controller during the charging process, which can be calculated by the product of current and voltage, wherein the current and voltage are collected and obtained by the corresponding sensors. PWM signal refers to pulse width modulation (Pulse Width Modulation) signal, which is a common signal form in digital output circuits, used for analog signal control and power conversion. PWM signal controls the average value of the signal by adjusting the width of the output pulse (i.e., the duration of the high level or low level), thereby achieving the purpose of controlling power output. It is judged whether the charging power needs to adjust the PWM signal to perform power control operation. The stable power is the power input to the vehicle charging port after the controller adjusts the charging power.

[0052] S3: Based on the time characteristics, the charging power, the corresponding stable power and the PWM signal are collected in real time, a data set is generated, and a mathematical analysis model is constructed. The mathematical analysis model outputs the prediction result of the stable power within a preset period in the future based on the data set.

[0053] Specifically, in this embodiment, the time feature refers to the information corresponding to the timestamp, and the charging power, stable power and PWM signal all contain the time information corresponding to the time feature, and the data set can be associated with the analysis based on the time feature. The mathematical analysis model refers to a mathematical model used for target analysis, and the relationship between variables can be established through the data features or physical laws between the variables in the data set, wherein the method of constructing the mathematical analysis model includes but is not limited to correlation analysis, differential equations, statistical models and other algorithms. The data set contains historical data corresponding to the charging power, stable power and PWM signal. The future preset period refers to the time period from the current time to the future. The prediction result refers to the numerical sequence of the target variable output by the mathematical analysis model within the future preset period.

[0054] S4: Obtain the prediction error of the mathematical analysis model, generate an optimized prediction result corresponding to the prediction result based on the prediction error, adjust the charging plan based on the optimized prediction result to generate a recommended plan, and complete the charging demand.

[0055] Specifically, in this embodiment, the prediction error is used to evaluate the accuracy of the mathematical analysis model, and optimizing the prediction result means adjusting the parameters of the mathematical analysis model by the prediction error and outputting a numerical sequence corresponding to the prediction result. The recommended plan is information adjusted corresponding to the charging plan, for example, the charging time interval. The recommended plan can reduce the battery loss when the car is charging and improve the stability of charging.

[0056] As a preferred technical solution of the present invention, stable power is generated based on the following steps:

[0057] Within a preset time range, the controller is started, and the controller includes a PWM analysis unit, an MCU main control unit and a PWM sending unit.

[0058] The PWM analysis unit receives and analyzes the PWM signal sent by the charging pile.

[0059] The MCU main control unit receives the charging plan, generates a planned PWM signal based on the charging plan, compares the duty cycle between the PWM signal and the planned PWM signal, and if the duty cycle of the planned PWM signal is smaller than the duty cycle of the PWM signal, sends the duty cycle of the planned PWM signal to the PWM sending unit.

[0060] The PWM sending unit receives the planned PWM signal sent by the MCU main control unit, generates a modulation signal based on the duty cycle of the planned PWM signal, and regulates the charging power to a stable power based on the modulation signal.

[0061] Specifically, in this embodiment, the preset time range refers to the preparation time required to perform power control when the controller is connected to the vehicle charging port and the charging gun head port for charging. For example, if the preset time range is set to 1 minute, the charging power will not be controlled within one minute of charging. The purpose is to ensure normal charging first, and then perform time calibration on the controller to adjust the internal clock of the controller to prepare for the parameters of the subsequent control instructions. The working principle of the controller is as follows Figure 2 shown.

[0062] The control instruction refers to the instruction information corresponding to the actual operation in the charging plan. The duty cycle of the PWM signal refers to the ratio of the time the signal is in a high-level state to the entire cycle time within a cycle. If the planned PWM signal duty cycle is less than the PWM signal duty cycle, it means that the AC power at the charging gun port needs to be controlled.

[0063] Adjusting the duty cycle of the planned PWM signal can change the square wave waveform of the planned PWM signal, thereby generating a modulation signal, which is then used to control the fluctuation of the AC power, thereby adjusting the charging power corresponding to the AC power to output stable power.

[0064] For example, the control process is as follows: the main control unit (power consumption information collection main station) can issue control instructions (charging power + charging time; at this time, it is changed to power controller control) through the concentrator. If the main control unit does not issue other control instructions during this period, the charging power will be carried out according to the set value range. The set PWM signal is only the current limit value. The actual charging current is less than or equal to it until the charging time ends. If it is not fully charged after the end, it will switch back to the charging pile control. If the set charging time has not ended, and a new control instruction comes in at this time, then the new control instruction will be executed directly.

[0065] As a preferred technical solution of the present invention, a modulation signal is generated based on the following steps:

[0066] Obtain the voltage target value of the vehicle charging port, obtain the input voltage waveform corresponding to the charging power, and obtain the amplitude difference between the voltage target value and the input voltage waveform based on the timestamp.

[0067] Locate the half-cycle interval of the input voltage waveform, input the planned PWM signal within the half-cycle interval, correct the input voltage waveform based on the adjustment amount of the duty cycle of the planned PWM signal, and until the amplitude difference at the current timestamp belongs to the preset difference interval, set the planned PWM signal corresponding to the adjusted duty cycle as the modulation signal.

[0068] Specifically, in this embodiment, the voltage target value refers to the voltage value that the vehicle charging port needs to receive, and the input voltage waveform is the AC waveform corresponding to the real-time charging power, usually a sine waveform. The amplitude difference refers to the difference between the amplitude value of the voltage waveform and the voltage target value in any time period.

[0069] The half-cycle interval of the input voltage waveform refers to the upper half cycle of the sinusoidal waveform corresponding to the voltage waveform, because selecting the upper half cycle input PWM signal can make the controller generate a modulation signal that overlaps the input voltage waveform as much as possible. The duty cycle of the PWM signal usually ranges from 0% to 100%, and the duty cycle adjustment refers to the change in the duty cycle of the planned PWM signal. The input voltage waveform can be changed and corrected by the adjusted planned PWM signal, thereby changing the amplitude difference, so that the amplitude difference between the corrected input voltage waveform and the voltage target value belongs to the preset difference interval. Among them, increasing the duty cycle means that the power supply is connected to the load for a longer time in one cycle. This causes more energy to be transferred to the load, thereby increasing the output power; reducing the duty cycle means that the power supply is disconnected from the load for a longer time in one cycle. This reduces the transfer of energy, thereby reducing the output power.

[0070] As a preferred technical solution of the present invention, correcting the input voltage waveform based on the adjustment amount of the duty cycle of the planned PWM signal includes the following steps:

[0071] When the controller is started, the duty cycle of the received PWM signal should be greater than a first preset value (90%), and the difference between the duty cycle and the first preset value is obtained and set as the adjustment amount.

[0072] The duty cycle D of the planned PWM signal is generated based on the first formula, which is: Among them, I is the maximum charging current corresponding to the charging plan, and α and β are reference coefficients.

[0073] The duty cycle of the planned PWM signal is adjusted to be reduced in sequence based on the adjustment amount to generate a new duty cycle, and the new duty cycle is greater than a second preset value, and a modulation signal is generated based on the new duty cycle. The modulation signal corrects the input voltage waveform based on a filter, wherein the second preset value is less than the first preset value.

[0074] Specifically, in this embodiment, when the controller is started, the duty cycle of the initially received PWM signal is reset. In order to protect the safety of the rechargeable battery in the vehicle charging port, a larger duty cycle is first set, that is, the duty cycle of the PWM signal needs to be greater than a first preset value. For example, the first preset value is 90%, and the initial duty cycle is set to 95%, and the adjustment amount is: 95%-90%=5%.

[0075] In the first formula, the duty cycle of the planned PWM signal is associated with the maximum charging current in the charging plan, and there is a mapping relationship between the two.

[0076] Then the planned PWM signal decreases the duty cycle in turn according to the adjustment amount to generate a new planned PWM signal, which is the modulation signal. Among them, the duty cycle of the modulation signal needs to be greater than the second preset value. Setting the first preset value and the second preset value respectively can avoid the modulation signal from regulating the charging power too much or too little, and can improve the stability of power control. The characteristics of the output waveform, such as amplitude, frequency and smoothness, can be regulated by the duty cycle and frequency of the modulation signal, as well as the design parameters of the filter (such as capacitance value, inductance value), and the desired waveform (such as alternating current of a specific frequency) can be obtained from the high-frequency pulse to correct the input voltage waveform. Among them, the main function of the filter is to filter out signals within a specific frequency range from a group of signals, while suppressing or reducing signals in other frequency ranges.

[0077] As a preferred technical solution of the present invention, a mathematical analysis model is constructed based on the following steps:

[0078] The performance parameter data corresponding to the time characteristics of the vehicle charging port are obtained based on the preset tags, and the adjustment square wave waveform corresponding to the PWM signal is obtained based on the signal change trend corresponding to the charging power and the stable power. The charging power in the data set and the charging time in the charging plan are set as input variables, the adjustment square wave waveform is set as the target variable, and the performance parameter data is set as the intermediate variable. A mathematical analysis model is constructed based on the target variable, the input variable and the intermediate variable, wherein the adjustment square wave waveform refers to the square wave waveform corresponding to the modulation signal generated in real time after the controller is started.

[0079] Specifically, in this embodiment, the preset labels include but are not limited to battery capacity, battery temperature, power density and health status, etc. Performance parameter data refers to data corresponding to the preset labels and has time characteristics. The adjustment square wave waveform refers to the square wave waveform corresponding to the modulation signal generated in real time after starting the controller, wherein the signal change trends corresponding to the charging power and the stable power refer to the input voltage waveform before correction and the input voltage waveform after correction, respectively. Among them, the linear relationship between the charging power, the stable power and the adjustment square wave waveform can be described by the second formula, and the second formula is: Among them, P1 is the charging power, V1 is the voltage of the AC power, I1 is the average current of the AC power, P2 is the stable power, and H is the duty cycle of the regulated square wave waveform at the same time point. Therefore, a mathematical analysis model can be constructed to monitor the battery status and the grid status, and improve the accuracy of the controller to control the output power of the charging pile based on the PWM signal.

[0080] Input variables, target variables, and intermediate variables are all variable data types for building data analysis models. The relationship between variables can be established based on physical laws or empirical data, and then appropriate mathematical tools and methods can be selected to combine the relationships and tools to build a complete mathematical analysis model to describe the power conversion process of the charging pile, including the generation process of the PWM signal. Therefore, the regulated square wave waveform is set as the target variable.

[0081] As a preferred technical solution of the present invention, the prediction result of the stable power output by the mathematical analysis model in the future preset period based on the data set includes the following steps:

[0082] The regulated square wave waveform is input into the mathematical analysis model, and the mathematical analysis model generates a corresponding predicted PWM signal within a future preset period based on all signal change trends and intermediate variables.

[0083] A neural network prediction model is established. The neural network model is trained based on performance parameter data and outputs the performance parameter prediction results within a preset period in the future.

[0084] The mathematical analysis model predicts and generates a change value of the stable power within a future preset period based on the predicted PWM signal and the performance parameter prediction results, and sets the change value as the prediction result.

[0085] Specifically, in this embodiment, the signal change trend belongs to the input variable, and the mathematical analysis model can predict the change trend corresponding to the square wave waveform in the future preset period, that is, predict the PWM signal. Among them, the duty cycle corresponding to the predicted PWM signal can be used for subsequent prediction and analysis of stable power.

[0086] When using a single-phase AC charging pile to charge a car, the performance parameter data corresponding to the on-board charging port (including battery status coefficients, such as remaining power, health status, temperature, etc.) can be predicted by a neural network model. Among them, the neural network model has powerful nonlinear mapping capabilities and pattern recognition capabilities, and is suitable for dealing with complex, nonlinear prediction problems. Therefore, all performance parameter data can be collected as historical data for training and learning, and the performance parameter data at the current time point can be collected in real time as the evaluation basis of the neural network model, and real-time prediction can be performed, and the performance parameter prediction results within the preset period in the future can be generated. Among them, a recurrent neural network can be selected as the network structure of the neural network model, and the performance parameter prediction results are data groups corresponding to preset labels.

[0087] The mathematical analysis model combined with the predicted PWM signal and performance parameter prediction results in the future preset period can accurately predict the change value corresponding to the output stable power, which is the prediction result.

[0088] As a preferred technical solution of the present invention, adjusting the charging plan based on the prediction results to generate a recommended plan includes the following steps:

[0089] The actual duty cycle of the regulated square wave waveform in a future preset period is obtained in real time, and the root mean square error between the actual duty cycle and the duty cycle corresponding to the predicted PWM signal is calculated and set as the prediction error.

[0090] The parameters of the mathematical analysis model are adjusted based on the prediction error, and an optimized PWM signal corresponding to the predicted PWM signal and an optimized prediction result corresponding to the prediction result are output.

[0091] The charging plan also includes the voltage phase of the charging gun head port. The voltage phase is monitored based on the duty cycle of the optimized PWM signal, and the time interval corresponding to the charging time is adjusted based on the optimized prediction result. The adjusted charging plan is set as the recommended plan.

[0092] Specifically, in this embodiment, in order to improve the accuracy of power control, it is necessary to adjust the model parameters through the prediction error of the mathematical analysis model, wherein the actual duty cycle of the regulated square wave waveform obtained in real time is used as verification data, and the root mean square error of the duty cycle of the predicted PWM signal corresponding to the time point is calculated and set as the prediction error of the mathematical analysis model.

[0093] When adjusting the parameters of the mathematical analysis model based on the prediction error, the coefficient of correlation between the variables can be adjusted according to the numerical value of the prediction error, thereby adjusting the mathematical analysis model, and then the mathematical analysis model outputs the optimized PWM signal corresponding to the predicted PWM signal and the optimized prediction result corresponding to the prediction result.

[0094] The voltage phase of the charging gun port refers to the state of a specific moment in the periodic change of the voltage waveform. The "time position" of the voltage waveform can be focused on by optimizing the duty cycle of the PWM signal. Combined with the optimization prediction results, the optimal charging time distribution interval corresponding to the charging time can be adjusted and set, that is, the time interval. Adjust the charging plan to the recommended plan to meet the charging needs.

[0095] As a preferred technical solution of the present invention, the communication mode is set to a dual-mode communication mode.

[0096] Specifically, in this embodiment, the dual-mode communication method refers to HPLC+HRF dual-mode (High Power Line Carrier, high voltage power line carrier communication; High Rate Frequency, high frequency) to ensure the reliability and continuity of data transmission.

[0097] like Figure 3 As shown, the present invention also provides a charging pile power control system based on PWM signal control, which is used to implement the above-mentioned charging pile power control method based on PWM signal control. The system mainly includes:

[0098] Connect the module and connect the two ends of the controller to the vehicle charging port and the charging gun head port of the charging pile respectively. If the power supply type of the charging gun head port is AC, perform this step.

[0099] The power control module and the controller obtain the charging plan based on the preset communication mode, obtain the charging power of the charging gun head port based on the charging plan, receive the PWM signal, adjust the charging power in real time based on the PWM signal to generate stable power, and send it to the vehicle charging port.

[0100] The analysis and prediction module collects the charging power, the corresponding stable power and the PWM signal in real time based on the time characteristics, generates a data set, and constructs a mathematical analysis model. The mathematical analysis model outputs the prediction result of the stable power within a preset period in the future based on the data set.

[0101] The plan adjustment module obtains the prediction error of the mathematical analysis model, generates an optimized prediction result corresponding to the prediction result based on the prediction error, and adjusts the charging plan based on the optimized prediction result to generate a recommended plan to meet the charging needs.

[0102] It should be understood that, although each step in the flow chart of each embodiment of the present invention is shown in sequence according to the indication of the arrow, these steps are not necessarily performed in sequence according to the order indicated by the arrow. Unless there is a clear explanation in this article, the execution of these steps does not have a strict order restriction, and these steps can be performed in other orders. Moreover, at least a portion of the steps in each embodiment may include a plurality of sub-steps or a plurality of stages, and these sub-steps or stages are not necessarily performed at the same time, but can be performed at different times, and the execution order of these sub-steps or stages is not necessarily performed in sequence, but can be performed in turn or alternately with at least a portion of other steps or sub-steps or stages of other steps.

[0103] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program. The above-mentioned program can be stored in a non-volatile computer-readable storage medium. When the program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided in this application can include non-volatile and / or volatile memory. Non-volatile memory may include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM) or flash memory. Volatile memory may include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM is available in various forms, such as static RAM (SRAM), dynamic RAM (DRAM), synchronous DRAM (SDRAM), double data rate SDRAM (DDRSDRAM), enhanced SDRAM (ESDRAM), synchronous link (Synchlink) DRAM (SLDRAM), memory bus (Rambus) direct RAM (RDRAM), direct memory bus dynamic RAM (DRDRAM), and memory bus dynamic RAM (RDRAM).

[0104] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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.

[0105] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for those of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

[0106] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A charging pile power control method based on PWM signal control, characterized in that: The method comprises the following steps: S1: Connect the two ends of the controller to the vehicle charging port and the charging gun head port of the charging pile respectively. If the power supply type of the charging gun head port is AC, execute S2; S2: The controller obtains a charging plan based on a preset communication mode, obtains the charging power of the charging gun head port based on the charging plan, receives a PWM signal, adjusts the charging power in real time based on the PWM signal to generate stable power, and sends the stable power to the vehicle-mounted charging port; S3: collecting the charging power, the corresponding stable power and the PWM signal in real time based on time characteristics, generating a data set, and constructing a mathematical analysis model, wherein the mathematical analysis model outputs a prediction result of the stable power within a future preset period based on the data set; S4: Obtain the prediction error of the mathematical analysis model, generate an optimized prediction result corresponding to the prediction result based on the prediction error, adjust the charging plan based on the optimized prediction result to generate a recommended plan to meet the charging requirements.

2. A charging pile power control method based on PWM signal control according to claim 1, characterized in that: The stable power is generated based on the following steps: Within a preset time range, the controller is started, wherein the controller includes a PWM analysis unit, an MCU main control unit and a PWM sending unit; The PWM analysis unit receives and analyzes the PWM signal sent by the charging pile; The MCU main control unit receives the charging plan, generates a planned PWM signal based on the charging plan, compares the duty cycle between the PWM signal and the planned PWM signal, and if the duty cycle of the planned PWM signal is smaller than the duty cycle of the PWM signal, sends the duty cycle of the planned PWM signal to the PWM sending unit; The PWM sending unit receives the planned PWM signal sent by the MCU main control unit, generates a modulation signal based on the duty cycle of the planned PWM signal, and regulates the charging power to the stable power based on the modulation signal.

3. A charging pile power control method based on PWM signal control according to claim 2, characterized in that: The modulation signal is generated based on the following steps: Obtaining a voltage target value of the vehicle-mounted charging port, obtaining an input voltage waveform corresponding to the charging power, and obtaining an amplitude difference between the voltage target value and the input voltage waveform based on a timestamp; Locate the half-cycle interval of the input voltage waveform, input the planned PWM signal within the half-cycle interval, correct the input voltage waveform based on the adjustment amount of the duty cycle of the planned PWM signal, until the amplitude difference at the current timestamp belongs to the preset difference interval, and set the planned PWM signal corresponding to the adjusted duty cycle as the modulation signal.

4. A charging pile power control method based on PWM signal control according to claim 3, characterized in that: The step of correcting the input voltage waveform based on the adjustment amount of the duty cycle of the planned PWM signal comprises the following steps: When starting the controller, the duty cycle of the received PWM signal should be greater than a first preset value (90%), and the difference between the duty cycle and the first preset value is obtained and set as the adjustment amount; The duty cycle D of the planned PWM signal is generated based on a first formula, wherein the first formula is: Wherein, I is the maximum charging current corresponding to the charging plan, and α and β are reference coefficients; The duty cycle of the planned PWM signal is adjusted to be reduced in sequence based on the adjustment amount to generate a new duty cycle, and the new duty cycle is greater than a second preset value, and the modulation signal is generated based on the new duty cycle. The modulation signal corrects the input voltage waveform based on a filter, wherein the second preset value is less than the first preset value.

5. The charging pile power control method based on PWM signal control according to claim 1, characterized in that: The mathematical analysis model is constructed based on the following steps: The performance parameter data of the vehicle charging port corresponding to the time feature is obtained based on the preset tag, the adjustment square wave waveform corresponding to the PWM signal is obtained based on the signal change trend corresponding to the charging power and the stable power, the charging power in the data set and the charging time in the charging plan are set as input variables, the adjustment square wave waveform is set as the target variable, and the performance parameter data is set as the intermediate variable. The mathematical analysis model is constructed based on the target variable, the input variable and the intermediate variable, wherein the adjustment square wave waveform refers to the square wave waveform corresponding to the modulation signal generated in real time after the controller is started.

6. A charging pile power control method based on PWM signal control according to claim 5, characterized in that: The prediction result of the mathematical analysis model outputting the stable power in a future preset period based on the data set includes the following steps: Inputting the regulated square wave waveform into the mathematical analysis model, the mathematical analysis model generates a corresponding predicted PWM signal within a future preset period based on all the signal change trends and the intermediate variables; Establishing a neural network prediction model, wherein the neural network model is trained based on the performance parameter data and outputs a prediction result of the performance parameter within a future preset period; The mathematical analysis model predicts and generates a change value of the stable power within a future preset period based on the predicted PWM signal and the performance parameter prediction result, and sets the change value as the prediction result.

7. The charging pile power control method based on PWM signal control according to claim 1, characterized in that: The step of adjusting the charging plan based on the prediction result to generate a recommended plan comprises the following steps: Acquire the actual duty cycle of the regulated square wave waveform in a future preset period in real time, calculate the root mean square error between the actual duty cycle and the duty cycle corresponding to the predicted PWM signal, and set it as the predicted error; adjusting the parameters of the mathematical analysis model based on the prediction error, and outputting the optimized PWM signal corresponding to the predicted PWM signal and the optimized prediction result corresponding to the prediction result; The charging plan also includes the voltage phase of the charging gun head port, the voltage phase is monitored based on the duty cycle of the optimized PWM signal, and the time interval corresponding to the charging duration is adjusted based on the optimization prediction result, and the adjusted charging plan is set as the recommended plan.

8. The charging pile power control method based on PWM signal control according to claim 1, characterized in that: The communication mode is set as a dual-mode communication mode.

9. A charging pile power control system based on PWM signal control, used to implement the method according to any one of claims 1 to 8, characterized in that: The system includes the following modules: Connect the module to connect the two ends of the controller to the vehicle charging port and the charging gun head port of the charging pile respectively. If the power supply type of the charging gun head port is AC, perform this step; A power control module, wherein the controller obtains a charging plan based on a preset communication mode, obtains the charging power of the charging gun head port based on the charging plan, receives a PWM signal, adjusts the charging power in real time based on the PWM signal to generate stable power, and sends the stable power to the vehicle-mounted charging port; An analysis and prediction module collects the charging power, the corresponding stable power and the PWM signal in real time based on time characteristics, generates a data set, and constructs a mathematical analysis model, wherein the mathematical analysis model outputs a prediction result of the stable power within a future preset period based on the data set; The plan adjustment module obtains the prediction error of the mathematical analysis model, generates an optimized prediction result corresponding to the prediction result based on the prediction error, and adjusts the charging plan based on the optimized prediction result to generate a recommended plan to meet the charging demand.

Images