Noise reduction method and device for charging pile

Abstract

The present invention relates to the technical field of noise reduction of charging piles, and specifically provides a noise reduction method and device for a charging pile, the method comprising: obtaining the local time and the temperature of the charging pile power module, the module fan speed and the number of operations when the charging pile is running; calculating the final target value of the fan speed of the charging pile system, and adjusting the speed of the system fan according to it; turning on the ANC active noise reduction mode when the local time, the temperature of the power module or the number of operations meet the noise reduction conditions; turning off the ANC active noise reduction mode when the fault code of any power module is obtained, and adjusting the speed of the system fan according to the fault code; obtaining noise parameters and environmental parameters when performing ANC active noise reduction, and inputting them into a trained neural network to output the noise reduction data of the ANC active noise reduction mode, and adjusting the ANC active noise reduction mode accordingly. Thus, the noise during the operation of the charging pile can be effectively reduced, the noise reduction effect can be improved, and the noise reduction cost can be kept low.

Description

Technical Field

[0001] The present invention relates to the technical field of noise reduction of charging piles, and in particular to a noise reduction method for a charging pile and a noise reduction device for a charging pile. Background Art

[0002] At present, when reducing the noise of a charging pile, usually only a single noise reduction mode is adopted, such as only reducing the noise of the charging pile through an active noise reduction mode, which has the problem of limited noise reduction effect. Summary of the invention

[0003] In order to solve one of the above technical problems, the present invention proposes the following technical solution.

[0004] The first aspect of the present invention proposes a noise reduction method for a charging pile, comprising the following steps: obtaining the local time and the temperature, module fan speed and number of operations of the charging pile power module when the charging pile is running; calculating the final target value of the fan speed of the charging pile system according to the temperature, module fan speed and number of operations of the power module, and adjusting the speed of the system fan according to the target value; turning on the ANC (Active Noise Cancellation) active noise reduction mode when the local time, the temperature or the number of operations of the power module meet the noise reduction conditions; turning off the ANC active noise reduction mode when a fault code of any power module is obtained, and adjusting the speed of the system fan according to the fault code. When performing ANC active noise reduction, noise parameters and environmental parameters are obtained, and are input into a trained neural network to output noise reduction data of the ANC active noise reduction mode, and the ANC active noise reduction mode is adjusted accordingly.

[0005] In addition, the noise reduction method of the charging pile according to the above embodiment of the present invention may also have the following additional technical features.

[0006] According to one embodiment of the present invention, the final target value of the speed of the fan of the charging pile system is calculated according to the temperature of the power module, the module fan speed and the number of operations, including: determining a first duty cycle coefficient for regulating the speed of the fan of the charging pile system according to the temperature of the power module; determining a second duty cycle coefficient for regulating the speed of the fan of the charging pile system according to the module fan speed of the power module; determining a third duty cycle coefficient for regulating the speed of the fan of the charging pile system according to the number of operations of the power module; calculating the final target value of the speed of the fan of the charging pile system according to the first duty cycle coefficient, the second duty cycle coefficient and the third duty cycle coefficient, wherein the first duty cycle coefficient, the second duty cycle coefficient and the third duty cycle coefficient are all greater than 0 and less than 1.

[0007] According to one embodiment of the present invention, determining a first duty cycle coefficient for regulating the speed of a fan of a charging pile system according to the temperature of the power module includes: selecting a maximum temperature among the temperatures of the power module; when the maximum temperature is less than a first preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a first preset value; when the maximum temperature is greater than or equal to the first preset temperature and less than the second preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a second preset value; when the maximum temperature is greater than or equal to the second preset temperature and less than the third preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a third preset value; when the maximum temperature is greater than or equal to the third preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a fourth preset value, wherein the first preset value, the second preset value, the third preset value and the fourth preset value are different; determining the first duty cycle coefficient for regulating the speed of the fan of the charging pile system according to the first duty cycle.

[0008] According to one embodiment of the present invention, a second duty cycle coefficient for regulating the speed of a fan of a charging pile system is determined according to the module fan speed of the power module, including: calculating the fan speed coefficient of each power module according to the module fan speed of each power module; calculating a preliminary target value of the fan speed of the charging pile system according to the fan speed coefficients of all power modules; and determining the second duty cycle coefficient for regulating the speed of the fan of the charging pile system according to the preliminary target value of the system fan speed.

[0009] According to one embodiment of the present invention, the fan speed coefficient of each power module is calculated by the following formula:

[0010]

[0011] Among them, A i represents the fan speed coefficient of the i-th power module, Nij represents the speed of the j-th module fan of the i-th power module, m represents the number of module fans of the i-th power module, and Nmaxi represents the maximum speed of the module fan of the i-th power module.

[0012] According to one embodiment of the present invention, the preliminary target value of the system fan speed is calculated by the following formula:

[0013]

[0014] Among them, N s1 Indicates the initial target value of the system fan speed, A n Indicates the fan speed coefficient of the nth power module, n indicates the number of power modules, Nsmax indicates the maximum system fan speed, and B1 indicates the temperature correction coefficient of the system fan.

[0015] According to one embodiment of the present invention, a third duty cycle coefficient for regulating the speed of a fan of a charging pile system is determined according to the number of operating power modules, including: when the number of operating power modules is less than the first preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is a fifth preset value; when the number of operating power modules is greater than or equal to the first preset number and less than the second preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is a sixth preset value; when the number of operating power modules is greater than or equal to the second preset number and less than the third preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is a seventh preset value; when the number of operating power modules is greater than or equal to the third preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is an eighth preset value, wherein the fifth preset value, the sixth preset value, the seventh preset value and the eighth preset value are different; determining the third duty cycle coefficient for regulating the speed of the fan of the charging pile system according to the second duty cycle.

[0016] According to one embodiment of the present invention, the final target value of the fan speed of the charging pile system is calculated by the following steps:

[0017] N s2 =(2F+2T+N)*0.2*Nsmax

[0018] Among them, N s2 It represents the final target value of the fan speed of the charging pile system. F, T, and N represent the first duty cycle coefficient, the second duty cycle coefficient, and the third duty cycle coefficient respectively. Nsmax represents the maximum value of the system fan speed.

[0019] According to one embodiment of the present invention, the ANC active noise reduction mode is turned on when the local time, the temperature of the power module or the number of operations meet the noise reduction conditions, including: when the local time is daytime and the maximum temperature of the temperatures of each power module is greater than or equal to a second preset temperature or the number of operations is greater than or equal to a second preset number, the ANC active noise reduction mode is turned on; when the local time is nighttime, the ANC active noise reduction mode is turned on, and the system fan speed is maintained at not exceeding a speed threshold, and the temperature of each power module is periodically detected, and the ANC active noise reduction mode and the initial power limiting factor of the charging pile are adjusted according to the temperature detection results.

[0020] According to one embodiment of the present invention, the ANC active noise reduction mode and the initial power limiting factor of the charging pile are adjusted according to the temperature detection result, including: obtaining the initial power limiting factor of the charging pile; calculating the temperature rise according to the temperature detection result; when the temperature rise exceeds the first preset temperature rise, the initial power limiting factor is increased by a preset percentage, and the number of increases is recorded, when the number of increases exceeds the preset number and the temperature rise still exceeds the first preset temperature rise, the ANC active noise reduction mode is turned off, and it is determined whether the temperature rise drops back to the first preset temperature rise; if the temperature rise drops back to the first preset temperature rise, the ANC active noise reduction mode is restored; if the temperature rise does not drop back to the first preset temperature rise, the ANC active noise reduction mode is turned off; when the number of increases does not exceed the preset number and the temperature rise drops back to the second preset temperature rise, the decrease is stopped, wherein the first preset temperature rise is different from the second preset temperature rise.

[0021] According to one embodiment of the present invention, the speed of the system fan is adjusted according to the fault code, including: when the fault code is a temperature alarm fault code, controlling the charging pile system fan to run at full speed; when the fault code is a current reduction alarm fault code, increasing the speed of the charging pile system fan; maintaining the current speed of the system fan for a second preset time and then acquiring the fault code again, until no fault code is acquired, and then adjusting the speed of the system fan according to the final target value of the speed of the charging pile system fan.

[0022] According to one embodiment of the present invention, the noise parameters include noise frequency, amplitude and phase, the environmental parameters include ambient temperature, humidity and local time, and the neural network includes at least one of a recurrent neural network, a long short-term memory network, a convolutional neural network and a deep neural network.

[0023] The second aspect of the present invention proposes a noise reduction device for a charging pile, comprising: an acquisition module, used to obtain the local time and the temperature, module fan speed and number of operations of the charging pile power module when the charging pile is running; a first speed regulation module, used to calculate the final target value of the fan speed of the charging pile system according to the temperature, module fan speed and number of operations of the power module, and adjust the speed of the system fan accordingly; a noise reduction module, used to turn on the ANC active noise reduction mode when the local time, the temperature or the number of operations of the power module meet the noise reduction conditions; a second speed regulation module, used to turn off the ANC active noise reduction mode when a fault code of any power module is obtained, and adjust the speed of the system fan according to the fault code; an adjustment module, used to obtain noise parameters and environmental parameters when performing ANC active noise reduction, and input them into a trained neural network to output noise reduction data of the ANC active noise reduction mode, and adjust the ANC active noise reduction mode accordingly.

[0024] The technical solution of the embodiment of the present invention can effectively reduce the noise during the operation of the charging pile, improve the noise reduction effect, and maintain a low noise reduction cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The figure is a flow chart of a noise reduction method for a charging pile according to an embodiment of the present invention.

[0026] Figure 2 The flowchart is a method for calculating the final target value of the fan speed of the system according to an example of the present invention.

[0027] Figure 3 The figure is a flow chart of a nighttime trickle charging noise reduction strategy according to an example of the present invention.

[0028] Figure 4 The figure is a flowchart of an ANC active noise reduction mode according to an example of the present invention.

[0029] Figure 5 The flowchart of speed adjustment according to fault codes is an example of the present invention.

[0030] Figure 6 It is a structural block diagram of the noise reduction device of the charging pile according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] The charging pile of the embodiment of the present invention comprises a system fan and a plurality of power modules, each of which comprises a plurality of module fans, wherein the system fan and the module fans are both speed-regulated by controlling the output duty cycle.

[0033] Figure 1 The figure is a flow chart of a noise reduction method for a charging pile according to an embodiment of the present invention.

[0034] like Figure 1 As shown, the noise reduction method of the charging pile includes the following steps S1 to S5.

[0035] S1, when the charging pile is running, obtain the local time, the temperature of the charging pile power module, the module fan speed and the number of operations.

[0036] Specifically, when the charging pile is running, in order to reduce noise, it is necessary to obtain the local time of the charging pile in real time, obtain the temperature of each power module and the speed of the module fan of each power module through CAN communication, and determine the number of power modules in operation in the charging pile, that is, the number of operating modules.

[0037] S2, calculates the final target value of the fan speed of the charging pile system according to the temperature of the power module, the fan speed of the module and the number of operations, and adjusts the speed of the system fan accordingly.

[0038] Specifically, the duty cycle coefficient for controlling the system fan is calculated according to the temperature of the power module, the module fan speed and the number of operations, and then the final target value of the charging pile system fan speed is calculated according to the three duty cycle coefficients, and the system fan is controlled accordingly.

[0039] Therefore, the system fan speed is adjusted according to the final target value of the system fan speed to achieve noise reduction of the charging pile.

[0040] S3: Enable the ANC active noise reduction mode when the local time, the temperature of the power module, or the number of running units meet the noise reduction conditions.

[0041] Specifically, when the charging pile is running, if the local time reaches the noise reduction time, such as at night, the ANC active noise reduction mode is turned on to actively reduce the noise of the charging pile; if the temperature of the power module reaches a certain temperature, the ANC active noise reduction mode is turned on to actively reduce the noise of the charging pile; if the number of running power modules reaches a certain number, the ANC active noise reduction mode is turned on to actively reduce the noise of the charging pile. Active noise reduction objects include system fans, module fans and AC contactors (single action).

[0042] ANC active noise reduction mode: ANC system position is reserved outside the system fan. The ANC system includes a microphone, a noise control module, a power amplifier module and an ANC module. The microphone picks up internal noise and feeds the noise sound wave signal back to the noise control module. The noise control module generates a noise reduction wave signal through algorithm calculation and transmits it to the power amplifier module for signal amplification. The ANC module generates an anti-phase signal after processing. The noise reduction wave and the noise wave are superimposed in the air to offset the noise emitted by the charging pile during charging, and realize three-dimensional open sound field active noise reduction. The microphone is installed in the reserved position of the sheet metal at the lower end of the air outlet in the cabinet to collect noise sound wave signals. At the same time, a built-in speaker is used to generate sound waves with the opposite amplitude of the noise sound wave signal. The front door panel reserves the position of the ANC mainboard, which is sealed with an acrylic plate and reserved for the outlet position. The software side identifies the noise signal of the system, module fan\AC contactor, and simulates the size of the sound signal that the speaker needs to emit through the algorithm, so that the noise reduction capability can be adjusted (adjust the sound volume of the speaker). The platform side identifies whether there is a communication failure of the speaker / microphone and records the running time.

[0043] Therefore, in the process of adjusting the speed of the system fan according to the final target value of the system fan speed to achieve noise reduction, if the noise reduction conditions are met, the ANC noise reduction mode is actively turned on, that is, the noise in the cabinet is actively picked up and fed back to the speaker to transmit reverse sound waves for noise reduction, thereby achieving collaborative hybrid noise reduction and further improving the noise reduction effect.

[0044] S4: When a fault code of any power module is obtained, the ANC active noise reduction mode is turned off, and the system fan speed is adjusted according to the fault code.

[0045] Specifically, when the charging pile is running, the power module fault code can be identified in real time to determine whether the current power module is faulty. When a fault code exists, the ANC active noise reduction mode is forcibly turned off, and the plan of adjusting the system fan speed according to the final target value of the system fan speed in step S2 is canceled, and the system fan speed is adjusted according to the fault code. That is, the fault speed regulation logic is prioritized at this time until the fault of the power module is eliminated and step S2 is resumed, or S2 and S3.

[0046] That is to say, when the power module is not faulty, step S2 is executed to adjust the speed of the system fan. At this time, the ANC active noise reduction mode of step S3 can be executed to achieve the coordinated noise reduction of the charging pile; when the power module is faulty, the solution of step S2 is canceled, and the system fan is adjusted according to the fault code first, and the ANC active noise reduction mode of step S3 is turned off. In short, the fault code speed adjustment mode of step S4 is independent of the speed adjustment mode according to the final target value of step S2 and the ANC active noise reduction mode of step S3, and cannot be performed at the same time.

[0047] During the charging process, if the duty cycle of the system fan exceeds 0.5s, it is judged as a delay. If there is no communication, try to reconnect three times. If there is still no communication, report the abnormal situation and stop charging.

[0048] S5, when performing ANC active noise reduction, obtaining noise parameters and environmental parameters, and inputting them into the trained neural network to output noise reduction data of the ANC active noise reduction mode, and adjusting the ANC active noise reduction mode accordingly.

[0049] The noise parameters include noise frequency, amplitude and phase, the environmental parameters include ambient temperature, humidity and local time, and the neural network includes at least one of recurrent neural networks (RNN), long short-term memory networks (LSTM), convolutional neural networks (CNN) and deep neural networks (DNN). The noise reduction data of the ANC active noise reduction mode refers to the noise reduction time, noise reduction power, ANC module loss and other data related to noise reduction.

[0050] RNN: Converts audio signals into digital signals for recording; captures long-term dependencies in noise-reduced data.

[0051] LSTM: effectively processes single-segment long sequence data in noise reduction mode, such as data with a long time period during night noise reduction; enhances the generalization ability of the model, learns the noise reduction habits of the site type, and summarizes the rules.

[0052] CNN: Build a noise image model to perform targeted noise reduction on spike signals; implement adaptive noise reduction and make adaptive adjustments based on the built noise image model. Dynamically adjust the noise reduction strategy according to different noise conditions to improve the noise reduction effect.

[0053] DNN: Automatically extract effective features (noise spikes, frequency, etc.) from noisy data; improve noise reduction effect and quality.

[0054] Specifically, the selected neural network is trained using a labeled data set (for example, the parameters of the optimal ANC system under certain noise and environmental conditions are known). The frequency, amplitude, phase and environmental characteristics of the noise are extracted during charging, such as temperature, humidity, time, etc., and input into the trained neural network to output noise reduction data. Based on the noise reduction data, decisions are made to step-by-step adjust the parameters of the ANC system. The network model is updated and optimized regularly or irregularly using new data and feedback information. This includes adjusting the model architecture (such as increasing or decreasing the number of layers and nodes of the neural network), updating the model parameters (retraining the model), etc., in order to continuously improve the performance and accuracy of the model and adapt to changes in the working environment of the charging pile and increased noise reduction needs.

[0055] For example, the current noise is 85dB, and the ANC module is turned on, which means it enters the ANC active noise reduction mode. At this time, RNN and LSTM jointly retrieve the scene where the noise reached 85dB before, analyze the power of the ANC module in the scene, as well as the decibel / time curve of noise attenuation generated by CNN in the previous noise reduction process, the internal temperature of the module, the operating power of the ANC module and other data. Through the analysis of the above data, DNN calculates the average value of each data in the noise reduction strategy, compares it with the current noise reduction strategy, estimates the time node for reducing to the target noise, and the loss of the ANC module. After comparison, the noise reduction effect is adjusted according to the charging habits of the station (for example, charging two heavy trucks in an industrial park at the same time can reduce the power occupied by the ANC module, sacrificing the speed of noise reduction to reduce the reactive power loss of the charging pile).

[0056] Therefore, the ability to cope with non-stationary noise is improved through neural networks, and the noise reduction strategy is dynamically adjusted according to different noise conditions to improve the noise reduction effect and quality.

[0057] The noise reduction method of the charging pile of the embodiment of the present invention can perform ANC active noise reduction and dynamically adjust the ANC noise reduction mode while performing noise reduction according to the temperature of the power module, the fan speed and the number of operations. When the power module fails, the noise reduction is turned off, and the speed regulation mode is switched to adjust the speed of the system fan according to the fault. In this way, the noise during the operation of the charging pile can be effectively reduced, the noise reduction effect can be improved, and the noise reduction cost can be kept low.

[0058] In one embodiment, the calculation of the final target value of the fan speed of the charging pile system according to the temperature of the power module, the module fan speed and the number of operations in step S2 may include: determining a first duty cycle coefficient for regulating the speed of the charging pile system fan according to the temperature of the power module; determining a second duty cycle coefficient for regulating the speed of the charging pile system fan according to the module fan speed of the power module; determining a third duty cycle coefficient for regulating the speed of the charging pile system fan according to the number of operations of the power module; calculating the final target value of the fan speed of the charging pile system according to the first duty cycle coefficient, the second duty cycle coefficient and the third duty cycle coefficient, wherein the first duty cycle coefficient, the second duty cycle coefficient and the third duty cycle coefficient are all greater than 0 and less than 1.

[0059] In one example, determining a first duty cycle coefficient for regulating the speed of a fan of a charging pile system according to the temperature of a power module may include: selecting a maximum temperature among the temperatures of the power module; when the maximum temperature is less than a first preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a first preset value; when the maximum temperature is greater than or equal to the first preset temperature and less than a second preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a second preset value; when the maximum temperature is greater than or equal to the second preset temperature and less than a third preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a third preset value; when the maximum temperature is greater than or equal to the third preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a fourth preset value, wherein the first preset value, the second preset value, the third preset value and the fourth preset value are different; determining the first duty cycle coefficient for regulating the speed of the fan of the charging pile system according to the first duty cycle.

[0060] Among them, the first to third preset temperatures are set according to actual needs, and can specifically be temperature values ​​determined based on the relationship between the power module temperature and noise. For example, the first to third preset temperatures are 20°C, 30°C, and 50°C, respectively.

[0061] The first to fourth preset values ​​are duty cycles set according to actual needs, and can be specifically set according to the corresponding relationship between temperature and duty cycle.

[0062] Specifically, if Figure 2 As shown, during charging, the temperature of the charging pile power module can be collected in real time, and the maximum temperature is selected therefrom. When the maximum temperature is less than 20°C, the first duty cycle for regulating the speed of the charging pile system fan is determined to be a first preset value of 30%; when the maximum temperature is greater than or equal to 20°C and less than 30°C, the first duty cycle for regulating the speed of the charging pile system fan is determined to be a second preset value of 50%; when the maximum temperature is greater than or equal to 30°C and less than 50°C, the first duty cycle for regulating the speed of the charging pile system fan is determined to be a third preset value (the current temperature of the module + 40)%; when the maximum temperature is greater than or equal to 50°C, the first duty cycle for regulating the speed of the charging pile system fan is determined to be a fourth preset value of 50%.

[0063] According to the first, second, third or fourth preset value of the first duty cycle, a first duty cycle coefficient T corresponds to, for example, the first preset value 30% corresponds to a first duty cycle coefficient of 0.4.

[0064] In one example, determining a second duty cycle coefficient for regulating the speed of a charging pile system fan based on the module fan speed of the power module may include: calculating the fan speed coefficient of each power module based on the module fan speed of each power module; calculating a preliminary target value for the charging pile system fan speed based on the fan speed coefficients of all power modules; and determining a second duty cycle coefficient for regulating the speed of the charging pile system fan based on the preliminary target value of the system fan speed.

[0065] Specifically, refer to Figure 2 When charging at the charging pile, first read the module fan speed of each power module in the cabinet, and calculate the fan speed coefficient of each power module by the following formula:

[0066]

[0067] Among them, A i represents the fan speed coefficient of the i-th power module, Nij represents the speed of the j-th module fan of the i-th power module, m represents the number of module fans of the i-th power module, and Nmaxi represents the maximum speed of the module fan of the i-th power module.

[0068] Then, according to the fan speed coefficient, the preliminary target value of the system fan speed is calculated by the following formula:

[0069]

[0070] Among them, N s1 Indicates the initial target value of the system fan speed, A n Indicates the fan speed coefficient of the nth power module, n indicates the number of power modules, Nsmax indicates the maximum fan speed of the system, and B1 indicates the temperature correction coefficient of the system fan. s1 If Nsmax is exceeded, then N s1 =Nsmax.

[0071] Finally, according to the corresponding relationship between the system fan speed and the duty cycle, the duty cycle coefficient corresponding to the preliminary target value of the system fan speed is determined, that is, the second duty cycle coefficient F.

[0072] In one example, determining a third duty cycle coefficient for regulating the speed of a fan of a charging pile system based on the number of operating power modules may include: when the number of operating power modules is less than the first preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is a fifth preset value; when the number of operating power modules is greater than or equal to the first preset number and less than the second preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is a sixth preset value; when the number of operating power modules is greater than or equal to the second preset number and less than the third preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is a seventh preset value; when the number of operating power modules is greater than or equal to the third preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is an eighth preset value, wherein the fifth preset value, the sixth preset value, the seventh preset value and the eighth preset value are different; determining the third duty cycle coefficient for regulating the speed of the fan of the charging pile system based on the second duty cycle.

[0073] Among them, the first to third preset numbers are set according to actual needs, and can be specifically determined based on the relationship between the number of operating power modules and noise. For example, the first to third preset numbers are 4, 7, and 10 respectively.

[0074] The fifth to eighth preset values ​​are duty cycles set according to actual needs, and can be specifically set according to the corresponding relationship between the rotation speed and the duty cycle.

[0075] Specifically, refer to Figure 2 When the charging pile is charging, the number of power modules in operation is determined. When the number of operation is less than 4, the second duty cycle for adjusting the speed of the system fan is determined to be the fifth preset value of 50%; when the number of operation is greater than or equal to 4 and less than 7, the second duty cycle for adjusting the speed of the system fan is determined to be the sixth preset value of 60%; when the number of operation is greater than or equal to 7 and less than 10, the second duty cycle for adjusting the speed of the system fan is determined to be the seventh preset value of 80%; when the number of operation is greater than or equal to 10, the second duty cycle for adjusting the speed of the system fan is determined to be the eighth preset value of 100%. The third duty cycle coefficient N is obtained according to the second duty cycle.

[0076] In one embodiment, the final target value of the fan speed of the charging pile system is calculated by the following formula:

[0077] N s2 =(2F+2T+N)*0.2*Nsmax

[0078] Among them, N s2 It indicates the final target value of the fan speed of the charging pile system. F, T, and N respectively represent the first duty cycle coefficient, the second duty cycle coefficient, and the third duty cycle coefficient. Nsmax represents the maximum value of the system fan speed (factory setting).

[0079] Therefore, through the weight distribution of T, F, and N, the final target value of the fan speed of the charging pile system is calculated, and the speed is adjusted accordingly. There is a corresponding relationship between the fan speed and noise of the charging pile system, so the noise reduction of the charging pile can be achieved through speed regulation.

[0080] In one embodiment of the present invention, turning on the ANC active noise reduction mode when the local time, the temperature of the power module or the number of operations meet the noise reduction conditions in step S3 may include: turning on the ANC active noise reduction mode when the local time is daytime and the maximum temperature of the temperatures of each power module is greater than or equal to a second preset temperature or the number of operations is less than a second preset number; turning on the ANC active noise reduction mode when the local time is nighttime, and maintaining the system fan speed not exceeding the speed threshold S, and periodically performing temperature detection on each power module, and adjusting the initial power limiting factor of the charging pile and the ANC active noise reduction mode according to the temperature detection results.

[0081] Furthermore, adjusting the ANC active noise reduction mode and the initial power limiting factor of the charging pile according to the temperature detection result may include: obtaining the initial power limiting factor of the charging pile; calculating the temperature rise according to the temperature detection result; when the temperature rise exceeds the first preset temperature rise, increasing the initial power limiting factor by a preset percentage, and recording the number of increases; when the number of increases exceeds the preset number and the temperature rise still exceeds the first preset temperature rise, turning off the ANC active noise reduction mode, and judging whether the temperature rise drops back to the first preset temperature rise; if the temperature rise drops back to the first preset temperature rise, restoring the ANC active noise reduction mode; if the temperature rise does not drop back to the first preset temperature rise, turning off the ANC active noise reduction mode; when the number of increases does not exceed the preset number and the temperature rise drops back to the second preset temperature rise, stopping the decrease.

[0082] The first preset temperature rise is different from the second preset temperature rise. The first preset temperature rise is (C-5)K, and the second preset temperature rise is (C-10)K, where C is a preset temperature rise threshold, and K is a temperature unit (Kelvin).

[0083] Specifically, refer to Figure 2 When the charging pile is charging, during the day, when the maximum temperature of the power module is greater than or equal to the second preset temperature of 30°C, the ANC active noise reduction mode is turned on; when the number of running power modules is greater than or equal to the second preset number 7, the ANC active noise reduction mode is turned on.

[0084] like Figure 3As shown, when the charging pile is charging, the ANC active noise reduction mode is turned on at night. Set the start time of the noise reduction mode to A, the closing time to D, the maximum speed of the system fan in the noise reduction mode to S, and the initial power limit factor of the charging pile to B. That is, after time A, the system turns on the ANC active noise reduction mode and maintains the system fan speed ≤ S. The temperature of the power module is detected every 5 minutes, B is corrected, and the temperature rise threshold is set to C, where n is the number of consecutive increases. When the temperature rise exceeds (C-5)K, B is adjusted to B'=B+n*5%. If it still exceeds (C-5)K after three consecutive increases, the noise reduction mode is turned off, and the temperature rise point exceeding the specified temperature is reported to the platform. After the temperature rise drops back to (C-5)K, the ANC active noise reduction mode is restored. After B is adjusted, when the temperature rise drops back to ≤(C-10)K and is maintained for 10 minutes, the downward adjustment is stopped; the values ​​of A and D can be set manually and can be turned off; the S setting value must ensure that the detection noise is ≤50dB, and the built-in decibel test instrument is used for correction.

[0085] Therefore, charging stations do not need high-power rapid charging at night. This algorithm is to determine the starting point of trickle charging through time information and maintain low-noise charging at night.

[0086] The process of ANC active noise reduction mode is as follows Figure 4 As shown:

[0087] Input sound waves: The microphone collects sound waves and collects sound signals in the environment. In the program logic of the microphone module, in addition to detecting sound, it can also detect the noise characteristics of the current environment, such as frequency distribution, noise type, etc. (software logic, not reflected in the flow chart).

[0088] Conditional judgment and processing: The collected noise signal first enters the conditional judgment of noise decibel to determine whether the noise is greater than or equal to 25dB. If it is greater than or equal to 25dB, it enters the FxLMS (Filtered-X Least Mean Square) module, which is used to calculate and generate a signal with the opposite phase to the noise to reduce the outside world's perception of noise. If the collected noise is less than 25dB, the noise collection is cyclic.

[0089] Noise reduction processing: After being processed by the FxLMS (adaptive filtering) module, the speaker converts the digital signal into a sound signal, and cancels it out by superimposing it with the sound waves of the noise, and superimposing the reverse signal with the original noise.

[0090] ANC active noise reduction mode off: When the noise at any noise receiving point in the system is reduced to ≤35dB, the ANC module is turned off.

[0091] Therefore, when the local time and the power module meet certain conditions, ANC active noise reduction is performed, the noise inside the cabinet is actively picked up, and the reverse sound waves are fed back to the speaker to offset the noise reduction.

[0092] In one embodiment of the present invention, the speed of the system fan is adjusted according to the fault code in step S4, which may include: when the fault code is a temperature alarm fault code, controlling the charging pile system fan to run at full speed; when the fault code is a current reduction alarm fault code, increasing the speed of the charging pile system fan; maintaining the current speed of the system fan for a second preset time and then acquiring the fault code again, until no fault code is acquired, and then adjusting the speed of the system fan according to the final target value of the speed of the charging pile system fan.

[0093] Specifically, if Figure 5 As shown, during the charging and noise reduction process, it is determined whether the fault code of any power module is obtained. If so, when the fault code is a current reduction alarm fault code, the control system fan runs at full speed. When the fault code is a temperature alarm fault code, the ANC active noise reduction mode is turned off, and the speed of the system fan is increased by 5% by controlling the duty cycle. When any power module does not have a current reduction alarm and a temperature alarm, the control system fan is decelerated by 5%.

[0094] After adjusting the system fan speed, maintain the current speed for 3 minutes and perform fault detection again until the module fault is eliminated.

[0095] It should be noted that when an over-temperature fault occurs during charging, speed regulation based on the fault takes precedence over noise reduction mode.

[0096] In summary, the noise reduction method of the charging pile in the embodiment of the present invention, ANC and speed regulation, and algorithm are parallel, which can effectively reduce the noise of the charging pile during operation while maintaining a low noise reduction cost, and solve the problems of limited noise reduction effect and high cost in traditional noise reduction methods.

[0097] Corresponding to the noise reduction method for a charging pile in the above embodiment, the present invention further proposes a noise reduction device for a charging pile.

[0098] Figure 6 It is a structural block diagram of the noise reduction device of the charging pile according to an embodiment of the present invention.

[0099] like Figure 6 As shown, the noise reduction device of the charging pile includes an acquisition module 10, a first speed regulation module 20, a noise reduction module 30, a second speed regulation module 40 and an adjustment module 50.

[0100] The acquisition module 10 is used to obtain the local time and the temperature of the charging pile power module, the module fan speed and the number of operations when the charging pile is running; the first speed regulation module 20 is used to calculate the final target value of the charging pile system fan speed according to the temperature of the power module, the module fan speed and the number of operations, and adjust the speed of the system fan accordingly; the noise reduction module 30 is used to turn on the ANC active noise reduction mode when the local time, the temperature of the power module or the number of operations meet the noise reduction conditions; the second speed regulation module 40 is used to turn off the ANC active noise reduction mode when the fault code of any power module is obtained, and adjust the speed of the system fan according to the fault code; the adjustment module 50 is used to obtain noise parameters and environmental parameters when performing ANC active noise reduction, and input them into a trained neural network to output noise reduction data of the ANC active noise reduction mode, and adjust the ANC active noise reduction mode accordingly.

[0101] It should be noted that the specific implementation of the noise reduction device of the charging pile can refer to the specific implementation of the noise reduction method of the above-mentioned charging pile. To avoid redundancy, it will not be described in detail here.

[0102] The noise reduction device for the charging pile according to the embodiment of the present invention can effectively reduce the noise during the operation of the charging pile, improve the noise reduction effect, and maintain a low noise reduction cost.

[0103] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be construed as limitations on the present invention, and those of ordinary skill in the art can change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A noise reduction method for a charging pile, characterized in that: The following steps are involved: When the charging pile is running, obtain the local time, the temperature of the charging pile power module, the module fan speed and the number of operations; Calculate the final target value of the fan speed of the charging pile system according to the temperature of the power module, the fan speed of the module and the number of operations, and adjust the speed of the fan of the system according to the final target value; Turning on the ANC active noise reduction mode when the local time, the temperature of the power module or the number of operations meets the noise reduction condition; When a fault code of any power module is obtained, the ANC active noise reduction mode is turned off, and the speed of the system fan is adjusted according to the fault code; When performing ANC active noise reduction, noise parameters and environmental parameters are obtained and input into a trained neural network to output noise reduction data of the ANC active noise reduction mode, and the ANC active noise reduction mode is adjusted accordingly.

2. The noise reduction method for a charging pile according to claim 1, characterized in that: The final target value of the fan speed of the charging pile system is calculated according to the temperature of the power module, the fan speed of the module and the number of operations, including: Determining a first duty cycle coefficient for regulating the speed of a fan of a charging pile system according to the temperature of the power module; Determining a second duty cycle coefficient for regulating the speed of the fan of the charging pile system according to the module fan speed of the power module; Determining a third duty cycle coefficient for adjusting the speed of a fan of a charging pile system according to the number of operating power modules; The final target value of the fan speed of the charging pile system is calculated according to the first duty cycle coefficient, the second duty cycle coefficient and the third duty cycle coefficient, wherein the first duty cycle coefficient, the second duty cycle coefficient and the third duty cycle coefficient are all greater than 0 and less than 1.

3. The noise reduction method for a charging pile according to claim 2, characterized in that: Determining a first duty cycle coefficient for adjusting the speed of a fan of a charging pile system according to the temperature of the power module includes: Selecting a maximum temperature among the temperatures of the power module; When the maximum temperature is less than the first preset temperature, determining that the first duty cycle for adjusting the speed of the fan of the charging pile system is a first preset value; When the maximum temperature is greater than or equal to the first preset temperature and less than the second preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is the second preset value; When the maximum temperature is greater than or equal to the second preset temperature and less than the third preset temperature, determining that the first duty cycle for regulating the speed of the fan of the charging pile system is a third preset value; When the maximum temperature is greater than or equal to the third preset temperature, determining that the first duty cycle for adjusting the speed of the fan of the charging pile system is a fourth preset value, wherein the first preset value, the second preset value, the third preset value and the fourth preset value are different; A first duty cycle coefficient for regulating the speed of the fan of the charging pile system is determined according to the first duty cycle.

4. The noise reduction method for a charging pile according to claim 2, characterized in that: Determining a second duty cycle coefficient for adjusting the speed of the fan of the charging pile system according to the module fan speed of the power module includes: Calculate the fan speed coefficient of each power module according to the fan speed of each module of each power module; Calculate the initial target value of the fan speed of the charging pile system according to the fan speed coefficients of all power modules; A second duty cycle coefficient for regulating the speed of the charging pile system fan is determined according to the preliminary target value of the system fan speed.

5. The noise reduction method for a charging pile according to claim 4, characterized in that: The fan speed factor for each power module is calculated using the following formula: Among them, A i represents the fan speed coefficient of the i-th power module, Nij represents the speed of the j-th module fan of the i-th power module, m represents the number of module fans of the i-th power module, and Nmaxi represents the maximum speed of the module fan of the i-th power module.

6. The noise reduction method for a charging pile according to claim 4, characterized in that: The preliminary target value of the system fan speed is calculated by the following formula: Among them, N s1 Indicates the initial target value of the system fan speed, A n Indicates the fan speed coefficient of the nth power module, n indicates the number of power modules, Nsmax indicates the maximum system fan speed, and B1 indicates the temperature correction coefficient of the system fan.

7. The noise reduction method for a charging pile according to claim 2, characterized in that: Determining a third duty cycle coefficient for adjusting the speed of a fan of a charging pile system according to the number of operating power modules includes: When the number of the power modules in operation is less than the first preset number, determining that the second duty cycle for adjusting the speed of the fan of the charging pile system is a fifth preset value; When the number of the power modules in operation is greater than or equal to the first preset number and less than the second preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is a sixth preset value; When the number of the power modules in operation is greater than or equal to the second preset number and less than the third preset number, determining that the second duty cycle for regulating the speed of the fan of the charging pile system is a seventh preset value; When the number of operating power modules is greater than or equal to the third preset number, determining that the second duty cycle for adjusting the speed of the fan of the charging pile system is an eighth preset value, wherein the fifth preset value, the sixth preset value, the seventh preset value and the eighth preset value are different from each other; A third duty cycle coefficient for adjusting the speed of the fan of the charging pile system is determined according to the second duty cycle.

8. The noise reduction method for a charging pile according to claim 2, characterized in that: The final target value of the fan speed of the charging pile system is calculated by the following steps: N s2 =(2F+2T+N)*0.2*Nsmax Among them, N s2 It represents the final target value of the fan speed of the charging pile system. F, T, and N represent the first duty cycle coefficient, the second duty cycle coefficient, and the third duty cycle coefficient respectively. Nsmax represents the maximum value of the system fan speed.

9. The noise reduction method for a charging pile according to claim 1, characterized in that: When the local time, the temperature of the power module, or the number of operations of the power module meets the noise reduction condition, the ANC active noise reduction mode is turned on, including: When the local time is daytime and the maximum temperature among the temperatures of the power modules is greater than or equal to a second preset temperature or the number of operations is greater than or equal to a second preset number, turning on the ANC active noise reduction mode; When the local time is nighttime, the ANC active noise reduction mode is turned on, and the system fan speed is maintained at a speed threshold. At the same time, the temperature of each power module is periodically detected, and the ANC active noise reduction mode and the initial power limiting factor of the charging pile are adjusted according to the temperature detection results.

10. The noise reduction method for a charging pile according to claim 9, characterized in that: The ANC active noise reduction mode and the initial power limit factor of the charging pile are adjusted according to the temperature detection results, including: Obtain the initial power limit factor of the charging pile; Calculating the temperature rise according to the temperature detection result; When the temperature rise exceeds the first preset temperature rise, the initial power limit factor is increased by a preset percentage, and the number of increases is recorded; when the number of increases exceeds the preset number and the temperature rise still exceeds the first preset temperature rise, the ANC active noise reduction mode is turned off, and it is determined whether the temperature rise falls back to the first preset temperature rise; If the temperature rise drops back to the first preset temperature rise, the ANC active noise reduction mode is restored; if the temperature rise does not drop back to the first preset temperature rise, the ANC active noise reduction mode is turned off; When the number of upward adjustments does not exceed the preset number of times and the temperature rise drops back to the second preset temperature rise, the downward adjustment is stopped, wherein the first preset temperature rise is different from the second preset temperature rise.

11. The noise reduction method for a charging pile according to claim 1, characterized in that: The system fan is speed-regulated according to the fault code, including: When the fault code is a temperature warning fault code, the fan of the charging pile system is controlled to run at full speed; When the fault code is a current reduction alarm fault code, increase the speed of the fan of the charging pile system; The current speed of the system fan is maintained for a second preset time and then the fault code is obtained again, and the speed of the system fan is adjusted according to the final target value of the speed of the charging pile system fan when no fault code is obtained.

12. The noise reduction method for a charging pile according to claim 1, characterized in that: The noise parameters include noise frequency, amplitude and phase, the environmental parameters include ambient temperature, humidity and local time, and the neural network includes at least one of a recurrent neural network, a long short-term memory network, a convolutional neural network and a deep neural network.

13. A noise reduction device for a charging pile, characterized in that: include: The acquisition module is used to obtain the local time, the temperature of the charging pile power module, the module fan speed and the number of operations when the charging pile is running; A first speed regulation module, used to calculate the final target value of the fan speed of the charging pile system according to the temperature of the power module, the module fan speed and the number of operations, and to regulate the speed of the system fan according to the final target value; A noise reduction module, used to turn on the ANC active noise reduction mode when the local time, the temperature of the power module or the number of operations meet the noise reduction conditions; A second speed regulating module, used for turning off the ANC active noise reduction mode when a fault code of any power module is obtained, and regulating the speed of the system fan according to the fault code; The adjustment module is used to obtain noise parameters and environmental parameters when performing ANC active noise reduction, and input them into the trained neural network to output noise reduction data of the ANC active noise reduction mode, and adjust the ANC active noise reduction mode accordingly.

Images