Inverter load reduction control method and inverter load reduction control system

Abstract

The present application relates to an inverter load reduction control method and an inverter load reduction control system, wherein the inverter load reduction control method comprises: obtaining the current temperature of the inverter; judging whether the current temperature of the inverter is greater than a preset target temperature; if so, comparing the current temperature of the inverter with the preset target temperature to obtain the current temperature deviation; when the current temperature deviation is greater than a first preset temperature deviation, controlling the inverter to speed up the load reduction speed so that the temperature of the inverter approaches the preset target temperature; when the current temperature deviation is within the range of a second preset temperature deviation and a first preset temperature deviation; controlling the inverter to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature, thereby solving the problem of large fluctuations in inverter temperature changes and power loss caused by inverter load reduction, reducing temperature fluctuations during inverter load reduction, reducing power loss, and improving the efficiency of the inverter.

Description

Technical Field

[0001] The present application relates to the field of inverters, and in particular to an inverter load reduction control method and an inverter load reduction control system. Background Art

[0002] Photovoltaic inverter is a power adjustment device mainly composed of switching elements such as transistors, which is used to convert the DC power of solar panels into AC power. When the inverter is fully loaded at a normal ambient temperature (40°C), the temperature of the internal components of the inverter is designed to be within its operating temperature. However, when extreme weather occurs (for example, an ambient temperature of 50°C), the installation components will have an extreme temperature of about 70°C under direct sunlight, and the high-temperature objects outside the photovoltaic components and the inverter will transfer heat to the inverter housing. In such extreme weather, the temperature of the inverter will exceed the rated operating temperature range, causing overheating. Once the inverter overheats, its internal components may be damaged. When overheating occurs, its internal components will directly alarm and stop working, or the inverter will reduce the load and power after reaching the predetermined temperature to reduce the heat generated, thereby reducing the temperature of the inverter. Most existing inverters reduce the load linearly according to the temperature, that is, the inverter temperature and the current power correspond one to one. Figure 1a It is a power curve diagram of the inverter in the prior art that performs linear load reduction according to temperature. Figure 1b This is a temperature curve diagram of the inverter in the prior art that performs linear load reduction according to temperature. Since the NTC temperature sensor is not attached to the hottest point of the inverter, and heat conduction and temperature rise take time, the collected inverter temperature will have a large lag relative to the hottest point, such as Figure 1a As shown in Figure 2, this method of linear load reduction according to temperature will cause the inverter power to oscillate at the thermal equilibrium point, such as Figure 1b As shown in the figure, this method of linear load reduction based on temperature will cause the inverter temperature to fluctuate greatly around the target temperature. Excessive power fluctuations will have a certain impact on the power grid, and even if the power generation is not the maximum, it will also cause a loss of power transmission.

[0003] With regard to the problem in the related art that inverter load reduction leads to large fluctuations in inverter temperature and loss of transmitted power, no effective solution has been proposed so far. Summary of the invention

[0004] In this embodiment, an inverter load reduction control method and an inverter load reduction control system are provided to solve the problem in the related art that inverter load reduction causes large fluctuations in inverter temperature and loss of transmitted power.

[0005] In a first aspect, an inverter load reduction control method is provided in this embodiment, including:

[0006] Get the current temperature of the inverter;

[0007] Determine whether the current temperature of the inverter is greater than the preset target temperature;

[0008] If so, compare the current temperature of the inverter with the preset target temperature to obtain the current temperature deviation;

[0009] When the current temperature deviation is greater than the first preset temperature deviation, the inverter is controlled to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature;

[0010] When the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation, the inverter is controlled to slow down the speed of load reduction so that the temperature of the inverter approaches the preset target temperature.

[0011] In some embodiments, before determining whether the current temperature of the inverter is greater than a preset target temperature, the method further includes:

[0012] Determine whether the current temperature of the inverter is greater than the over-temperature protection threshold of the inverter;

[0013] If yes, the inverter is controlled to stop working.

[0014] In some embodiments, if the current temperature of the inverter is lower than a preset target temperature, the inverter is controlled to operate at a preset maximum power.

[0015] In some embodiments, when the current temperature deviation is greater than the first preset temperature deviation, controlling the inverter to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature includes:

[0016] Adjust the proportional coefficient of the proportional-integral controller to a preset first range value, and control the inverter to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature; wherein the proportional-integral controller is used to adjust the working state of the inverter, and the maximum value of the preset first range value is the numerical upper limit of the proportional coefficient.

[0017] In some embodiments, when the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation; controlling the inverter to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature includes:

[0018] Adjust the proportional coefficient of the proportional-integral controller to a preset second range value, and control the inverter to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature; wherein the proportional-integral controller is used to adjust the working state of the inverter, and the minimum value of the preset second range value is the lower limit of the proportional coefficient.

[0019] In some embodiments, adjusting the proportional coefficient of the proportional-integral controller to a preset first range value, and controlling the inverter to accelerate the speed of load reduction so that the temperature of the inverter approaches a preset target temperature, includes:

[0020] Adjust the proportional coefficient of the proportional-integral controller to a preset first range value, adjust the integral coefficient of the proportional-integral controller to a preset third range value, and control the inverter to speed up the load reduction; wherein the maximum value of the preset third range value is the numerical upper limit of the integral coefficient.

[0021] In some embodiments, adjusting the proportional coefficient of the proportional-integral controller to a preset second range value to control the inverter to slow down the load reduction speed so that the temperature of the inverter approaches a preset target temperature includes:

[0022] Adjusting the proportional coefficient of the proportional-integral controller to a preset second range value, adjusting the integral coefficient of the proportional-integral controller to a preset fourth range value, and controlling the inverter to slow down the speed of load shedding;

[0023] The minimum value of the preset fourth range value is the lower limit of the integral coefficient.

[0024] In some embodiments, when the temperature deviation is less than a second preset temperature deviation, the inverter is controlled to operate at a preset maximum power and continue to detect the current temperature.

[0025] In a second aspect, an inverter load reduction control system is provided in this embodiment, and the inverter load reduction control method described in any one of the first aspects is applied. The inverter load reduction control system includes: a temperature sampling circuit, a proportional integral controller and an inverter, wherein;

[0026] Temperature sampling circuit, used to collect the current temperature of the inverter in real time;

[0027] A proportional-integral controller, used to control the output power of the inverter according to the temperature deviation between the current temperature of the inverter and a preset target temperature;

[0028] The inverter is used to execute the output instruction of the proportional-integral controller so that the temperature of the inverter tends to a preset temperature.

[0029] In some embodiments, the temperature sampling circuit includes: a first resistor, a second resistor, a thermistor, a capacitor, and an analog-to-digital converter, wherein:

[0030] The input end of the first resistor is connected to the power supply end, the output end of the first resistor is connected to the input end of the second resistor and the input end of the thermistor, the output end of the thermistor is connected to the reference ground, the output end of the second resistor is connected to the input end of the analog-to-digital converter and the first plate of the capacitor, and the second plate of the capacitor is connected to the reference ground;

[0031] The analog-to-digital converter is used to convert the received analog signal into the current temperature value of the inverter.

[0032] Compared with the related art, the inverter load reduction control method provided in the present embodiment obtains the current temperature of the inverter; determines whether the current temperature of the inverter is greater than the preset target temperature; if so, compares the current temperature of the inverter with the preset target temperature to obtain the current temperature deviation; when the current temperature deviation is greater than the first preset temperature deviation, controls the inverter to speed up the load reduction speed so that the temperature of the inverter approaches the preset target temperature; when the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation; controls the inverter to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature, thereby solving the problem of large fluctuations in inverter temperature changes and power loss caused by inverter load reduction, reducing temperature fluctuations during inverter load reduction, reducing power loss, and improving the efficiency of the inverter.

[0033] Details of one or more embodiments of the present application are set forth in the following drawings and description to make other features, objects, and advantages of the present application more readily apparent. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application and do not constitute an improper limitation on the present application. In the drawings:

[0035] Figure 1a It is a power curve diagram of the inverter in the prior art that performs linear load reduction according to temperature.

[0036] Figure 1b It is a temperature curve diagram of the inverter in the prior art that performs linear load reduction according to temperature.

[0037] Figure 2 It is a hardware structure block diagram of a terminal of the inverter load reduction control method of this embodiment.

[0038] Figure 3 is a flow chart of the inverter load reduction control method of this embodiment.

[0039] Figure 4 is a flow chart of another inverter load reduction control method of this embodiment.

[0040] Figure 5 Schematic diagram of the structure of the inverter load reduction control system of this embodiment.

[0041] Figure 6 Schematic diagram of the temperature sampling circuit structure of this embodiment. DETAILED DESCRIPTION

[0042] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments.

[0043] Unless otherwise defined, the technical terms or scientific terms involved in this application shall have the general meaning understood by people with general skills in the technical field to which this application belongs. The words "one", "a", "the", "these" and the like in this application do not indicate a quantitative limitation, and they may be singular or plural. The terms "include", "comprise", "have" and any variants thereof involved in this application are intended to cover non-exclusive inclusions; for example, a process, method and system, product or device comprising a series of steps or modules (units) is not limited to the listed steps or modules (units), but may include unlisted steps or modules (units), or may include other steps or modules (units) inherent to these processes, methods, products or devices. The words "connect", "connected", "coupled" and the like involved in this application are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. The "multiple" involved in this application refers to two or more. "And / or" describes the association relationship of associated objects, indicating that there may be three relationships, for example, "A and / or B" may mean: A exists alone, A and B exist at the same time, and B exists alone. Generally, the character " / " indicates that the objects associated with each other are in an "or" relationship. The terms "first", "second", "third", etc. in this application are only used to distinguish similar objects and do not represent a specific ordering of the objects.

[0044] The method embodiment provided in this embodiment can be executed in a terminal, a computer or a similar computing device. For example, running on a terminal, Figure 2 is a hardware structure block diagram of a terminal of the inverter load reduction control method of this embodiment. Figure 2 As shown, the terminal may include one or more ( Figure 2 Only one is shown in the figure) processor 202 and memory 204 for storing data, wherein processor 202 may include but is not limited to a processing device such as a microprocessor MCU or a programmable logic device FPGA. The above terminal may also include a transmission device 206 and an input and output device 208 for communication functions. It can be understood by those skilled in the art that Figure 2 The structure shown is only for illustration and does not limit the structure of the above terminal. Figure 2 More or fewer components as shown, or with Figure 2 Different configurations shown.

[0045] The memory 204 can be used to store computer programs, for example, software programs and modules of application software, such as the computer program corresponding to the inverter load reduction control method in this embodiment. The processor 202 executes various functional applications and data processing by running the computer program stored in the memory 204, that is, to implement the above method. The memory 204 may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some examples, the memory 204 may further include a memory remotely arranged relative to the processor 202, and these remote memories may be connected to the terminal via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0046] The transmission device 206 is used to receive or send data via a network. The above network includes a wireless network provided by the communication provider of the terminal. In one example, the transmission device 206 includes a network adapter (Network Interface Controller, referred to as NIC), which can be connected to other network devices through a base station so as to communicate with the Internet. In one example, the transmission device 206 can be a radio frequency (Radio Frequency, referred to as RF) module, which is used to communicate with the Internet wirelessly.

[0047] In this embodiment, a method for controlling inverter load reduction is provided. Figure 3 is a flow chart of the inverter load reduction control method of this embodiment, such as Figure 3 As shown, the process includes the following steps:

[0048] Step S301, obtaining the current temperature of the inverter.

[0049] Specifically, in order to prevent the inverter from being damaged due to overheating, the temperature of the inverter is detected in real time. According to the operating temperature range and environmental conditions of the inverter, a suitable temperature sensor is selected, such as a thermocouple, thermistor or semiconductor sensor. In order to ensure the accuracy of the detected temperature of the inverter, the temperature sensor can be arranged in key parts of the inverter, such as near the power module, capacitor and transformer. The current temperature of the inverter is collected in real time through the arranged temperature sensor, and the controller obtains the current temperature of the inverter in real time.

[0050] Step S302, determining whether the current temperature of the inverter is greater than a preset target temperature; if so, comparing the current temperature of the inverter with the preset target temperature to obtain a current temperature deviation.

[0051] Specifically, after the controller receives the current temperature of the inverter, it first determines whether it is greater than the preset target temperature, wherein the preset target temperature is the optimal operating temperature value determined according to the inverter, which is affected by the operating temperature of the components, the heat dissipation effect of the inverter and the ambient temperature. The target temperature of different inverters is different and can be set according to the actual situation. This is not specifically limited in this embodiment. At the target temperature, the inverter can output maximum power operation and output the maximum amount of electricity to achieve the best effect. When the current temperature of the inverter detected is greater than the preset target temperature, it is necessary to control the inverter to reduce the load and reduce the output power of the inverter to reduce the current temperature of the inverter. Before reducing the load, the difference between the current temperature of the inverter and the preset target temperature is calculated to obtain the current temperature deviation, and the output power of the inverter is further controlled according to the current temperature deviation.

[0052] Step S303: when the current temperature deviation is greater than the first preset temperature deviation, the inverter is controlled to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature.

[0053] Specifically, during the operation of the inverter, due to the influence of the ambient temperature and its own power output, the current temperature of the inverter shows a large up and down fluctuation trend near the target temperature, and its output power also shows an up and down fluctuation trend at the thermal equilibrium point. A first preset temperature deviation is set in advance, wherein the first preset temperature deviation is a temperature deviation that is manually set to determine that the current temperature of the inverter is in a high state, that is, when it deviates far from the target temperature, the output power of the inverter needs to be controlled. The first preset temperature deviation can be set according to actual conditions, and this embodiment does not make specific restrictions on this. For example, in this embodiment, the first preset temperature deviation is set to 7°C. When the current temperature deviation is greater than 7°C, it means that the current temperature of the inverter is in a high state and deviates far from the target temperature. The control coefficient of the controller is adjusted to prompt the inverter to speed up the load reduction speed, so that the temperature of the inverter drops in a short time and gradually approaches the target temperature.

[0054] Step S304, when the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation; control the inverter to slow down the speed of load reduction so that the temperature of the inverter approaches the preset target temperature.

[0055] Specifically, when the load shedding speed of the inverter is controlled by the controller, a second preset temperature deviation is set, wherein the second preset temperature deviation is a temperature deviation that is manually set to determine that the current temperature of the inverter is in a low state, that is, when it is close to the target temperature, the output power of the inverter needs to be controlled. The second preset temperature deviation can be set according to actual conditions, and this embodiment does not specifically limit this. For example, in this embodiment, the second preset temperature deviation is set to 2°C. When the current temperature deviation is between 2°C and 7°C, it means that the current temperature of the inverter is higher than the target temperature, but is close to the target temperature. At this time, the control coefficient of the controller is adjusted to slow down the speed of the inverter load shedding, so that the temperature of the inverter decreases at a slower rate and gradually approaches the target temperature.

[0056] Through the above steps S301 to S304, the current temperature of the inverter is obtained; it is determined whether the current temperature of the inverter is greater than the preset target temperature; if so, the current temperature of the inverter is compared with the preset target temperature to obtain the current temperature deviation; when the current temperature deviation is greater than the first preset temperature deviation, the inverter is controlled to speed up the load reduction speed so that the temperature of the inverter approaches the preset target temperature; when the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation; the inverter is controlled to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature. Compared with the prior art method of directly performing linear load reduction according to temperature, the present application controls the inverter through a controller to speed up the load reduction when the inverter is at a high temperature, that is, far from the target temperature. When the inverter is close to the target temperature, the controller inverter slows down the load reduction. Through continuous debugging, the inverter can be quickly adjusted to near the target temperature when the temperature exceeds the target temperature, and operate at maximum power, thereby reducing the temperature fluctuation of the inverter, allowing the inverter to quickly reach a thermal equilibrium state, and allowing the inverter power and temperature to tend to the target stable state, thereby increasing the amount of power sent.

[0057] In some of the embodiments, before determining whether the current temperature of the inverter is greater than a preset target temperature, the process further includes: determining whether the current temperature of the inverter is greater than an over-temperature protection threshold of the inverter; if so, controlling the inverter to stop working.

[0058] Specifically, the over-temperature protection threshold of the inverter is the maximum temperature limit that the inverter can withstand under normal working conditions. If the maximum temperature value is exceeded, the inverter may be damaged, affecting its performance and life, and even causing safety accidents. Therefore, when the controller receives the current temperature of the inverter, it first determines whether the current temperature of the inverter is greater than the over-temperature protection threshold of the inverter. If it is detected that the over-temperature protection threshold is exceeded, the inverter is directly controlled to stop working to avoid damage to the inverter.

[0059] In another embodiment, if the current temperature of the inverter is lower than a preset target temperature, the inverter is controlled to operate at a preset maximum power.

[0060] As mentioned above, the preset target temperature is the optimal operating temperature value determined according to the inverter. At the target temperature, the inverter can output the maximum power and achieve the maximum benefit. When the temperature sensor detects that the current temperature of the inverter is lower than the preset target temperature, in this case, it can be ensured that it is safe for the inverter to operate at the maximum power. In order to expand the benefit of the inverter, the inverter is controlled to operate according to the maximum power of the maximum power point tracking (MPPT), increase the amount of electricity sent by the inverter, and improve the working efficiency of the inverter. At the same time, the temperature sensor continues to detect the current temperature of the inverter in real time.

[0061] In some embodiments, when the current temperature deviation is greater than the first preset temperature deviation, controlling the inverter to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature includes:

[0062] Adjust the proportional coefficient of the proportional-integral controller to a preset first range value, and control the inverter to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature; wherein the proportional-integral controller is used to adjust the working state of the inverter, and the maximum value of the preset first range value is the numerical upper limit of the proportional coefficient.

[0063] When the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation; controlling the inverter to slow down the load reduction speed so that the temperature of the inverter tends to the preset target temperature, including:

[0064] Adjust the proportional coefficient of the proportional-integral controller to a preset second range value, and control the inverter to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature; wherein the proportional-integral controller is used to adjust the working state of the inverter, and the minimum value of the preset second range value is the lower limit of the proportional coefficient.

[0065] Specifically, in this embodiment, a proportional-integral controller (PI controller for short) is used to control the output power of the inverter. The output voltage and frequency of the inverter are adjusted by the PI controller, thereby adjusting the output power of the inverter. The time domain expression of the PI controller is:

[0066] ;

[0067] Among them, U( t ) is the output power of the inverter, is the proportional coefficient in the PI controller, e ( t ) is the current temperature deviation, is the integration time constant, K i =1 / T i is the integration coefficient, is the integral term, indicating the temperature deviation from time 0 to the current time t e ( t )

[0068] The transfer function G(s) of the PI controller is:

[0069] ;

[0070] in, s is a complex variable in the Laplace transform;

[0071] The transfer function of the PI controller in the control system can ensure that the system achieves the required performance indicators, such as fast response, no steady-state error and sufficient stability. K p and the integration time constant T i , the performance of the controller can be optimized.

[0072] First, the proportional system of the PI controller is divided into two range values. The original proportional range is 0-100, then 1-100 is set as the preset first range value, and the first range value is defined as a larger value of the proportional coefficient of the PI controller, and its maximum value is the numerical upper limit of the proportional coefficient range, that is, 100; 0-1 is set as the preset second range value, and the second range value is defined as a smaller value of the proportional coefficient of the PI controller, and its minimum value is the numerical lower limit of the proportional coefficient range, that is, 0.

[0073] When the current temperature deviation is greater than the first preset temperature deviation (in this embodiment, the first preset temperature deviation is 7°C), the proportional coefficient of the PI controller is adjusted to the first range of 1-100 to speed up the inverter load shedding. This adjustment process is a dynamic adjustment process. The output power of the inverter is controlled by adjusting the proportional coefficient of the PI controller, and then the temperature change speed of the inverter is detected. If it is detected that the change speed is still too slow and has not reached the preset effect, the proportional coefficient of the PI controller is increased to continue to adjust the output power of the inverter, so that the inverter load shedding reaches the expected speed and the temperature of the inverter is controlled to tend to the preset target temperature. In order to prevent the proportional coefficient K p Too large a value will cause violent oscillation and instability in power, so a suitable proportional coefficient needs to be selected.

[0074] When the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation (in this embodiment, the first preset temperature deviation is 7°C, and the second preset temperature deviation range is 2°C, that is, when the current temperature deviation is between 2°C and 7°C), since the temperature of the inverter is close to the target temperature at this time, the adjustment range should not be too large. At this time, too large adjustment is likely to cause large temperature fluctuations, which is not conducive to the inverter being stable near the target temperature, and is not conducive to the inverter power being stable at the thermal equilibrium point. The proportional coefficient of the PI controller is adjusted to the second range value 0-1 to slow down the speed of the inverter load reduction. This adjustment process is also a dynamic adjustment process. The output power of the inverter is controlled by adjusting the proportional coefficient of the PI controller, and then the temperature change speed of the inverter is detected. If it is detected that the change speed is still too fast and has not reached the preset effect, the proportional coefficient of the PI controller is reduced to continue to adjust the output power of the inverter, so that the inverter load reduction reaches the expected speed and the temperature of the inverter is controlled to tend to the preset target temperature.

[0075] In another embodiment, adjusting the proportional coefficient of the proportional-integral controller to a preset first range value, and controlling the inverter to accelerate the speed of load reduction so that the temperature of the inverter approaches a preset target temperature, includes:

[0076] Adjust the proportional coefficient of the proportional-integral controller to a preset first range value, adjust the integral coefficient of the proportional-integral controller to a preset third range value, and control the inverter to speed up the load reduction; wherein the maximum value of the preset third range value is the numerical upper limit of the integral coefficient.

[0077] Adjusting the proportional coefficient of the proportional-integral controller to a preset second range value, controlling the inverter to slow down the load reduction speed, so that the temperature of the inverter tends to a preset target temperature, including:

[0078] Adjust the proportional coefficient of the proportional-integral controller to a preset second range value, adjust the integral coefficient of the proportional-integral controller to a preset fourth range value, and control the inverter to slow down the load reduction speed; wherein the minimum value of the preset fourth range value is the lower limit of the integral coefficient.

[0079] Specifically, the integral system of the PI controller is first divided into two range values. The original proportional range is 0-1, and 0.1-1 is set as the preset third range value. The third range value is defined as a larger integral coefficient of the PI controller, and its maximum value is the numerical upper limit of the integral coefficient range, that is, 1; 0-0.1 is set as the preset fourth range value. The fourth range value is defined as a smaller integral coefficient of the PI controller, and its minimum value is the numerical lower limit of the integral coefficient range, that is, 0. Among them, the PI controller is controlled by the proportional coefficient K pIt can improve the inverter's response speed to voltage changes, reduce voltage deviation, and increase the integral coefficient on this basis. K i The regulation helps to eliminate steady-state errors, ensure that the output voltage can reach the set value, and further effectively control the output power.

[0080] When the current temperature deviation is greater than the first preset temperature deviation (in this embodiment, the first preset temperature deviation is 7°C), after the proportional coefficient of the PI controller is adjusted to within the first range value of 1-100, the integral coefficient of the PI controller is controlled to be adjusted within the third range value of 0.1-1. Similarly, the adjustment process is also a dynamic adjustment process. The output power of the inverter is controlled by adjusting the proportional coefficient and integral coefficient of the PI controller, and then the temperature change speed and stability of the inverter are detected. If it is detected that the change speed is still too slow and has not reached the preset effect, the proportional coefficient of the PI controller is increased to continue to adjust the output power of the inverter. If it is detected that the temperature change fluctuation of the inverter is abnormal, the integral coefficient of the PI controller is increased to make the load reduction of the inverter reach the expected speed, and the temperature of the inverter is controlled to tend to the preset target temperature.

[0081] When the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation (in this embodiment, the first preset temperature deviation is 7°C, and the second preset temperature deviation range is 2°C, that is, when the current temperature deviation is between 2°C and 7°C), the proportional coefficient of the PI controller is adjusted to the second range value of 0-1, and the integral coefficient of the PI controller is controlled to be adjusted within the fourth range value of 0-0.1. The adjustment process is also a dynamic adjustment process. The output power of the inverter is controlled by adjusting the proportional coefficient of the PI controller, and then the temperature change speed and stability of the inverter are detected. If it is detected that the change speed is still too fast and has not reached the preset effect, the proportional coefficient of the PI controller is reduced to continue to adjust the output power of the inverter. If it is detected that the temperature change fluctuation of the inverter is abnormal, the integral coefficient of the PI controller is reduced to make the load reduction of the inverter reach the expected speed, and the temperature of the inverter is controlled to tend to the preset target temperature.

[0082] In some embodiments, when the temperature deviation is less than a second preset temperature deviation, the inverter is controlled to operate at a preset maximum power and continues to detect the current temperature.

[0083] Specifically, when the detected temperature deviation is less than the second preset temperature deviation of 2°C, it means that the inverter is within the safe operating temperature range, that is, within the preset area away from the target temperature. At this time, there is no need to start the controller to adjust the inverter, and the inverter can be controlled to operate at maximum power to achieve maximum benefits. At the same time, the current temperature of the inverter continues to be detected through the temperature sensor.

[0084] This embodiment also provides an inverter load reduction control method. Figure 4 is a flow chart of another inverter load reduction control method of this embodiment. Figure 4 As shown, the process includes the following steps:

[0085] Step S401, obtaining the current temperature of the inverter;

[0086] Step S402, determining whether the current temperature of the inverter is greater than the over-temperature protection threshold of the inverter, if so, executing step S403, otherwise executing step S404;

[0087] Step S403, controlling the inverter to stop working;

[0088] Step S404, determining whether the current temperature of the inverter is greater than a preset target temperature, if so, executing step S405, otherwise, executing step S410;

[0089] Step S405, comparing the current temperature of the inverter with the preset target temperature to obtain a current temperature deviation;

[0090] Step S406, determining whether the current temperature deviation is greater than the first preset temperature deviation, if so, executing step S407, otherwise, executing step S408;

[0091] Step S407, adjusting the proportional coefficient of the proportional-integral controller to a preset first range value, adjusting the integral coefficient of the proportional-integral controller to a preset third range value, and controlling the inverter to speed up the load reduction until the temperature of the inverter approaches the preset target temperature and reaches thermal equilibrium;

[0092] Step S408, determining whether the current temperature deviation is greater than the second preset temperature deviation, if so, executing step S409, otherwise, executing step S410;

[0093] Step S409, adjusting the proportional coefficient of the proportional-integral controller to a preset second range value, adjusting the integral coefficient of the proportional-integral controller to a preset fourth range value, and controlling the inverter to slow down the speed of load reduction until the temperature of the inverter approaches the preset target temperature and reaches thermal equilibrium;

[0094] Step S410, controlling the inverter to operate at a preset maximum power, and returning to execute step S401.

[0095] Through the above steps S401 to S410, when the temperature of the inverter is lower than the target temperature or within the preset temperature difference (i.e., the temperature deviation is within 2°C), the present application controls the inverter to operate at maximum power, ensures the maximum benefit of the inverter, and increases the amount of electricity sent by the inverter. When the inverter is at a high temperature, i.e., far from the target temperature, the proportional coefficient and integral coefficient of the controller are adjusted to a larger range value to control the inverter to speed up the load reduction speed. When the inverter is close to the target temperature, the proportional coefficient and integral coefficient of the controller are adjusted to a smaller range value to control the inverter to slow down the load reduction speed. Through continuous debugging, the inverter can be quickly adjusted to near the target temperature when the temperature exceeds the target temperature, reducing the temperature fluctuation of the inverter, allowing the inverter to quickly reach a thermal equilibrium state, and making the inverter power and temperature tend to the target stable state, thereby improving the efficiency of the inverter.

[0096] In this embodiment, an inverter load reduction control system is also provided. The system applies the inverter load reduction control method described in any of the above embodiments. Figure 5 is a schematic diagram of the structure of the inverter load reduction control system of this embodiment, as shown in Figure 5 As shown, the inverter load reduction control system 50 includes: a temperature sampling circuit 51, a proportional integral controller 52 and an inverter 53, wherein;

[0097] The temperature sampling circuit 51 is used to collect the current temperature of the inverter in real time;

[0098] A proportional-integral controller 52, used to control the output power of the inverter according to a temperature deviation between the current temperature of the inverter and a preset target temperature;

[0099] The inverter 53 is used to execute the output instruction of the proportional-integral controller so that the temperature of the inverter tends to a preset temperature;

[0100] in, Figure 6 Schematic diagram of the temperature sampling circuit structure of this embodiment. Figure 6 As shown, the temperature sampling circuit 51 includes: a first resistor 61, a second resistor 62, a thermistor 63, a capacitor 64 and an analog-to-digital converter 65, wherein:

[0101] The input end of the first resistor 61 is connected to the power supply end, the output end of the first resistor 61 is connected to the input end of the second resistor 62 and the input end of the thermistor 63, the output end of the thermistor 63 is connected to the reference ground, the output end of the second resistor 62 is connected to the input end of the analog-to-digital converter 65 and the first plate of the capacitor 64, and the second plate of the capacitor 64 is connected to the reference ground; the analog-to-digital converter 65 is used to convert the received analog signal into the current temperature value of the inverter.

[0102] Specifically, in this embodiment, the thermistor 63 adopts an NTC thermistor, and uses its temperature-resistance characteristic (resistance decreases with increasing temperature) for detection. The analog-to-digital converter 65 adopts ADC for sampling, and converts the analog voltage signal into a digital signal through ADC sampling. After processing, the temperature value of the inverter is obtained.

[0103] In this embodiment, an electronic device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor is configured to run the computer program to execute the steps in any one of the above method embodiments.

[0104] Optionally, the electronic device may further include a transmission device and an input / output device, wherein the transmission device is connected to the processor, and the input / output device is connected to the processor.

[0105] Optionally, in this embodiment, the processor may be configured to perform the following steps through a computer program:

[0106] S1, obtain the current temperature of the inverter;

[0107] S2, determining whether the current temperature of the inverter is greater than a preset target temperature; if so, comparing the current temperature of the inverter with the preset target temperature to obtain a current temperature deviation;

[0108] S3, when the current temperature deviation is greater than the first preset temperature deviation, controlling the inverter to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature;

[0109] S4, when the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation; control the inverter to slow down the speed of load reduction so that the temperature of the inverter approaches the preset target temperature.

[0110] It should be noted that the specific examples in this embodiment can refer to the examples described in the above embodiments and optional implementation modes, and will not be repeated in this embodiment.

[0111] In addition, in combination with the inverter load reduction control method provided in the above embodiments, a storage medium may be provided in this embodiment to implement the method. The storage medium stores a computer program; when the computer program is executed by a processor, any of the inverter load reduction control methods in the above embodiments is implemented.

[0112] It should be understood that the specific embodiments described herein are only used to explain the application, rather than to limit it. Based on the embodiments provided in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the protection scope of this application.

[0113] Obviously, the drawings are only some examples or embodiments of the present application. For ordinary technicians in the field, the present application can also be applied to other similar situations based on these drawings without creative work. In addition, it is understandable that although the work done in this development process may be complicated and lengthy, for ordinary technicians in the field, certain changes in design, manufacturing or production based on the technical content disclosed in this application are only conventional technical means and should not be regarded as insufficient content disclosed in this application.

[0114] The term "embodiment" in this application refers to a specific feature, structure or characteristic described in conjunction with the embodiment that can be included in at least one embodiment of the present application. The appearance of this phrase in various locations in the specification does not necessarily mean the same embodiment, nor does it mean that it is mutually exclusive with other embodiments and is independent or optional. It is clearly or implicitly understood by those of ordinary skill in the art that the embodiments described in this application can be combined with other embodiments without conflict.

[0115] 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, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to the memory, database or other medium used in the embodiments provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetoresistive random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM). The database involved in each embodiment provided in this application may include at least one of a relational database and a non-relational database. Non-relational databases may include distributed databases based on blockchains, etc., but are not limited to this. The processor involved in each embodiment provided in this application may be a general-purpose processor, a central processing unit, a graphics processor, a digital signal processor, a programmable logic device, a data processing logic device based on quantum computing, etc., but are not limited to this.

[0116] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of patent protection. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims.

Claims

1. An inverter load reduction control method, characterized in that: include: Get the current temperature of the inverter; Determining whether the current temperature of the inverter is greater than a preset target temperature; If so, compare the current temperature of the inverter with the preset target temperature to obtain a current temperature deviation; When the current temperature deviation is greater than a first preset temperature deviation, controlling the inverter to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature; When the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation; controlling the inverter to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature; Wherein, when the current temperature deviation is greater than a first preset temperature deviation, controlling the inverter to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature includes: Adjust the proportional coefficient of the proportional-integral controller to a preset first range value, and control the inverter to speed up the load reduction so that the temperature of the inverter approaches the preset target temperature; wherein the proportional-integral controller is used to adjust the working state of the inverter, and the maximum value of the preset first range value is the numerical upper limit of the proportional coefficient.

2. The inverter load reduction control method according to claim 1, characterized in that: Before determining whether the current temperature of the inverter is greater than a preset target temperature, the method further includes: Determining whether the current temperature of the inverter is greater than an over-temperature protection threshold of the inverter; If so, the inverter is controlled to stop working.

3. The inverter load reduction control method according to claim 1, characterized in that: The method further comprises: If the current temperature of the inverter is lower than the preset target temperature, the inverter is controlled to operate at a preset maximum power.

4. The inverter load reduction control method according to claim 1, characterized in that: When the current temperature deviation is within the range of the second preset temperature deviation and the first preset temperature deviation; controlling the inverter to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature, including: Adjust the proportional coefficient of the proportional-integral controller to a preset second range value, and control the inverter to slow down the load reduction speed so that the temperature of the inverter approaches the preset target temperature; wherein the proportional-integral controller is used to adjust the working state of the inverter, and the minimum value of the preset second range value is the lower limit of the proportional coefficient.

5. The inverter load reduction control method according to claim 1, characterized in that: The step of adjusting the proportional coefficient of the proportional-integral controller to a preset first range value, and controlling the inverter to accelerate the speed of load reduction, so that the temperature of the inverter approaches the preset target temperature, includes: Adjust the proportional coefficient of the proportional-integral controller to a preset first range value, adjust the integral coefficient of the proportional-integral controller to a preset third range value, and control the inverter to speed up the load reduction; wherein the maximum value of the preset third range value is the numerical upper limit of the integral coefficient.

6. The inverter load reduction control method according to claim 4, characterized in that: The step of adjusting the proportional coefficient of the proportional-integral controller to a preset second range value, and controlling the inverter to slow down the load reduction speed, so that the temperature of the inverter approaches the preset target temperature, includes: Adjusting a proportional coefficient of a proportional-integral controller to a preset second range value, adjusting an integral coefficient of the proportional-integral controller to a preset fourth range value, and controlling the inverter to slow down the speed of load shedding; Among them, the minimum value of the preset fourth range value is the lower limit of the integral coefficient.

7. The inverter load reduction control method according to claim 1, characterized in that: The method further comprises: When the temperature deviation is less than the second preset temperature deviation, the inverter is controlled to operate at a preset maximum power and continues to detect the current temperature.

8. An inverter load reduction control system, applying the inverter load reduction control method according to any one of claims 1 to 7, characterized in that: The inverter load reduction control system comprises: a temperature sampling circuit, a proportional integral controller and an inverter, wherein; The temperature sampling circuit is used to collect the current temperature of the inverter in real time; The proportional-integral controller is used to control the output power of the inverter according to the temperature deviation between the current temperature of the inverter and the preset target temperature; The inverter is used to execute the output instruction of the proportional-integral controller so that the temperature of the inverter tends to a preset temperature.

9. The inverter load reduction control system according to claim 8, characterized in that: The temperature sampling circuit includes: a first resistor, a second resistor, a thermistor, a capacitor and an analog-to-digital converter, wherein: The input end of the first resistor is connected to the power supply end, the output end of the first resistor is connected to the input end of the second resistor and the input end of the thermistor, the output end of the thermistor is connected to the reference ground, the output end of the second resistor is connected to the input end of the analog-to-digital converter and the first plate of the capacitor, and the second plate of the capacitor is connected to the reference ground; The analog-to-digital converter is used to convert the received analog signal into a current temperature value of the inverter.

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