A photovoltaic inverter intelligent control system

Abstract

The present invention discloses a photovoltaic inverter intelligent control system, which belongs to the field of inverter control technology, and includes: a photovoltaic power generation module, which generates corresponding photovoltaic power according to weather information in a predetermined time period; a load monitoring module, which obtains the load power consumption in a predetermined time period to determine the power required by the load; an inverter control module, which determines the output power of the inverter according to the generated photovoltaic power and the power required by the load; wherein the inverter control module is also provided with an inverter data acquisition unit, a data analysis and processing unit, and an output power adjustment unit. The present invention conducts a comprehensive analysis based on the current change and temperature change during the operation of the inverter to determine the influence of the output power on the inverter performance, thereby performing corresponding power adjustment, thereby ensuring that the working performance of the inverter is not affected, thereby ensuring the normal output of power.

Description

Technical Field

[0001] The present invention belongs to the technical field of inverter control, and in particular relates to an intelligent control system for a photovoltaic inverter. Background Art

[0002] Photovoltaic inverters are inverters that can convert the variable DC voltage generated by photovoltaic solar panels into AC power at the mains frequency, which can be fed back to the commercial power transmission system or used for off-grid power grids. Photovoltaic inverters are one of the important system balances in photovoltaic array systems and can be used with general AC-powered equipment.

[0003] Generally, the output power of a photovoltaic inverter will be adjusted according to the amount of electricity generated by the photovoltaic panels within a predetermined time period on that day. When the photovoltaic panels generate more electricity, the output power of the photovoltaic inverter will be increased. When the photovoltaic panels generate less electricity, the output power of the photovoltaic inverter will be reduced accordingly. Although this method can maximize the use of photovoltaic electricity, the performance of the inverter is easily affected by the output power. When the output power of the inverter increases, the corresponding inverter temperature will also increase. If the inverter is always in a higher output power working mode, it will affect the service life of the inverter, thereby affecting the normal output of power. Summary of the invention

[0004] The purpose of the present invention is to provide a photovoltaic inverter intelligent control system to solve the problems faced in the above-mentioned background technology.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A photovoltaic inverter intelligent control system, the control system comprising:

[0007] A photovoltaic power generation module, the photovoltaic power generation module is used to generate corresponding photovoltaic power according to weather information within a predetermined time period;

[0008] A load monitoring module, the load monitoring module is used to obtain the load power usage within a predetermined time period to determine the amount of power required by the load;

[0009] An inverter control module, the inverter control module is used to determine the output power of the inverter according to the generated photovoltaic power and the power required by the load;

[0010] The inverter control module is also provided with an inverter data acquisition unit, a data analysis and processing unit and an output power adjustment unit;

[0011] The inverter data acquisition unit is used to obtain current change data information and temperature change data information of the photovoltaic inverter during operation;

[0012] The data analysis and processing unit performs comprehensive processing and analysis based on the acquired data information, thereby generating a power impact value, and determines whether to generate a power adjustment decision based on the power impact value;

[0013] An output power adjustment unit, wherein the output power adjustment unit adjusts the output power of the inverter after receiving the power adjustment decision.

[0014] Furthermore, the method in which the inverter control module determines the output power of the inverter according to the generated photovoltaic power and the power required by the load is:

[0015] Divide the scheduled time period into n monitoring segments and obtain the photovoltaic power generated in each monitoring segment And each detection segment can determine the amount of electrical energy required by the load ;

[0016] The photovoltaic power generated in each detection segment The energy required by the load is determined To compare:

[0017] when When , the output power of the monitoring segment is determined as ,in ;

[0018] when When , the output power of the monitoring segment is determined as ,in ;

[0019] In the formula, is the preset electric energy power conversion coefficient, The energy lost by photovoltaic power.

[0020] Furthermore, the photovoltaic power loss The method to obtain it is:

[0021] By formula The photovoltaic power loss ;

[0022] in, is the inverter conversion loss coefficient, is the line loss coefficient of the photovoltaic power station, is the number of working devices in the photovoltaic power station, and , For the The working time of each working device, For the The reference value of the working time of each working equipment, For the The amount of electrical energy required for a working device to operate.

[0023] Furthermore, the method for generating the power adjustment decision is:

[0024] Obtain the inverter current within the monitoring segment , and temperature Changes, thus constructing the curve equations of current and time, temperature and time in the monitoring section , ;

[0025] By formula Calculate the power impact value ;

[0026] The power impact value obtained The power impact threshold preset in the system To compare:

[0027] when When , a power adjustment decision is generated;

[0028] in, To monitor the start time of a small segment, To monitor the end time of a short segment, The standard function for the effect of temperature and current on the setting is: The current affects the reference value set. The reference value for the set temperature influence, The current influences the reference value for the set temperature.

[0029] Furthermore, the output power adjustment unit works as follows:

[0030] After receiving the power adjustment decision, the formula Reduce the output power of the next monitoring segment;

[0031] in, The inverter needs to reduce the output power. is the maximum output power that the system allows to adjust, is the preset power conversion factor.

[0032] Furthermore, the photovoltaic power The acquisition method is:

[0033] At standard temperature And standard light intensity Measure the standard photovoltaic power of photovoltaic panels ;

[0034] Get the light intensity change curve within the monitoring section And the temperature change curve , so that through the formula Get the photovoltaic power generated ;

[0035] in, is the temperature influence coefficient.

[0036] Furthermore, the electrical energy required by the load The acquisition method is:

[0037] According to the most recent period The load consumption changes of the same test section every day are used to determine the first load demand ;

[0038] The second load demand is determined based on the average load demand of the same period every year in the historical time m years. ;

[0039] Then through the formula Get the energy required by the load , as well as is the proportionality coefficient.

[0040] Beneficial effects of the present invention:

[0041] The present invention conducts a comprehensive analysis based on the current change and temperature change during the operation of the inverter to determine the impact of the output power on the inverter performance, thereby making corresponding power adjustments to ensure that the working performance of the inverter is not affected, thereby ensuring normal power output.

[0042] The present invention determines the output power of the photovoltaic inverter by performing a comprehensive analysis based on the obtained photovoltaic power and the power required by the load in combination with the comprehensive power loss factors of the photovoltaic power station. This can not only make the determined output power more accurate, but also make rational use of photovoltaic energy to ensure the normal operation of the photovoltaic power station.

[0043] Of course, any product implementing the present invention does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0045] Figure 1 It is a system block diagram of the present invention. DETAILED DESCRIPTION

[0046] 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.

[0047] In one embodiment, a photovoltaic inverter intelligent control system is disclosed, such as Figure 1 As shown, the regulatory system includes:

[0048] A photovoltaic power generation module, the photovoltaic power generation module is used to generate corresponding photovoltaic power according to weather information within a predetermined time period;

[0049] A load monitoring module is used to obtain the load power usage within a predetermined time period to determine the amount of power required by the load;

[0050] An inverter control module, the inverter control module is used to determine the output power of the inverter according to the generated photovoltaic power and the power required by the load;

[0051] The inverter control module is also provided with an inverter data acquisition unit, a data analysis and processing unit, and an output power adjustment unit;

[0052] The inverter data acquisition unit is used to obtain data information such as current changes and temperature changes of the photovoltaic inverter during operation;

[0053] The data analysis and processing unit performs comprehensive processing and analysis based on the acquired data information, thereby generating a power impact value, and determines whether to generate a power adjustment decision based on the power impact value;

[0054] The output power adjustment unit adjusts the output power of the inverter after receiving the power adjustment decision.

[0055] Through the above technical scheme, the present application first obtains the weather information within a predetermined time period according to the photovoltaic power generation module to generate the corresponding photovoltaic power, then obtains the load power consumption within the predetermined time period according to the load monitoring module to determine the load required power, and finally determines the output power of the photovoltaic inverter based on the obtained photovoltaic power and the load required power combined with the comprehensive power loss factors of the photovoltaic power station. This can make the determined output power more accurate and make rational use of photovoltaic energy to ensure the normal operation of the photovoltaic power station; at the same time, the inverter is also provided with an inverter data acquisition unit, a data analysis and processing unit and an input The output power adjustment unit obtains data information such as current changes and temperature changes of the photovoltaic inverter during operation, and then performs comprehensive processing and analysis based on the current changes and temperature changes to generate a power impact value. It then determines whether the set output power needs to be adjusted based on the power impact value. When adjustment is required, a power adjustment decision is generated to adjust the output power of the inverter. In this way, the impact of the output power on the inverter performance can be determined based on the current changes and temperature changes during the operation of the inverter, and corresponding power adjustments can be made to ensure that the working performance of the inverter is not affected, thereby ensuring the normal output of power.

[0056] As an embodiment of the present invention, a method for the inverter control module to determine the output power of the inverter according to the generated photovoltaic power and the power required by the load is:

[0057] Divide the scheduled time period into n monitoring segments and obtain the photovoltaic power generated in each monitoring segment And each detection segment can determine the amount of electrical energy required by the load ;

[0058] The photovoltaic power generated in each detection segment The energy required by the load is determined To compare:

[0059] when When , the output power of the monitoring segment is determined as ,in ;

[0060] when When , the output power of the monitoring segment is determined as ,in ;

[0061] In the formula, is the preset electric energy power conversion coefficient, is the photovoltaic power loss, of which photovoltaic power loss The method of obtaining is: through the formula The photovoltaic power loss ;

[0062] In the formula, is the inverter conversion loss coefficient, is the line loss coefficient of the photovoltaic power station, is the number of working devices in the photovoltaic power station, and , For the The working time of each working device, For the The reference value of the working time of each working equipment, For the The amount of electrical energy required for a working device to operate.

[0063] Through the above technical solution, this embodiment provides a specific method for the inverter control module to determine the output power of the inverter according to the generated photovoltaic power and the power required by the load. First, the predetermined time period is divided into n monitoring segments, and the photovoltaic power generated in each monitoring segment is obtained. And each detection segment can determine the amount of electrical energy required by the load Since the inverter output power is related to the amount of electrical energy required by the load, the photovoltaic electrical energy generated in each detection segment is The energy required by the load is determined Compare: When When the output power of the photovoltaic power is higher than the power required by the load, in order to avoid excessive power flowing into the grid and causing grid burden, the output power of the monitoring segment is adjusted to the power required by the load. The load is also related to the photovoltaic power loss of the photovoltaic station itself. Therefore, in order to ensure the normal operation of the photovoltaic power station, the final output power is determined as ; Similarly when When , it means that the photovoltaic power is lower than the power required by the load, and the photovoltaic power can be fully output, then the output power is adjusted to In order to ensure the normal operation of the photovoltaic power station, the output power of the final inverter is determined as . Photovoltaic energy loss Then through the formula It turns out that the formula It indicates the electric energy required for the photovoltaic station to work. The larger its value is, the greater the photovoltaic power loss is. The photovoltaic power loss is also related to the service life of the equipment. Generally speaking, the longer the service life is, the worse the performance is, and the greater the power loss is. Therefore, the formula The working hours of the photovoltaic station equipment are obtained and then introduced into the formula The photovoltaic power loss This can make the output photovoltaic power loss more accurate and facilitate the control of the inverter output power.

[0064] In the above technical solution, the preset electric energy power conversion coefficient , inverter conversion loss coefficient , photovoltaic power station line loss coefficient Can be determined according to its own performance parameters, Reference value of working time of each working equipment According to empirical data, The amount of electricity required for the working equipment It is determined based on the historical working power consumption of the corresponding equipment.

[0065] As an implementation mode of the present invention, a method for generating a power adjustment decision is as follows:

[0066] Obtain the inverter current within the monitoring segment , and temperature Changes, thus constructing the curve equations of current and time, temperature and time in the monitoring section , ;

[0067] By formula Calculate the power impact value ;

[0068] The power impact value obtained The power impact threshold preset in the system To compare:

[0069] when When , a power adjustment decision is generated;

[0070] in, To monitor the start time of a small segment, To monitor the end time of a short segment, The standard function for the effect of temperature and current on the setting is: The current affects the reference value set. The reference value for the set temperature influence, The current affects the reference value for the set temperature;

[0071] The working method of the output power adjustment unit is: after receiving the power adjustment decision, the formula Reduce the output power of the next monitoring segment;

[0072] in, The inverter needs to reduce the output power. is the maximum output power that the system allows to adjust, is the preset power conversion factor.

[0073] Through the above technical solution, this embodiment provides a method for generating a power adjustment decision and a method for adjusting the output power according to the power adjustment decision. First, the current of the inverter itself in the monitoring segment is obtained. , and temperature Changes, thus constructing the curve equations of current and time, temperature and time in the monitoring section , , so that through the formula Calculate the power impact value ; The formula represents the ratio between the current change and the current impact reference value. If the current is too large, overload danger may occur easily. If the current exceeds the inverter's tolerance value, it will also affect the inverter performance. It indicates the ratio between temperature change and temperature influence reference value. If the inverter temperature rises, it will affect the inverter performance. Formula Indicates the ratio between the change in the mutual influence relationship between temperature and current and the reference value of temperature and current influence. is the set temperature and current influence standard function, which can be obtained based on the relevant data in the big data. Because there is a mutual influence between temperature and current, if there is a large gap between the corresponding changes of the two in the inverter during operation and the corresponding standard changes of the two, it means that it will also affect the inverter performance; therefore, combined with the formula Comprehensive analysis to obtain power impact value , the power impact value obtained The power impact threshold preset in the system For comparison, when When , it means that the power impact value is large. In order to ensure the working performance of the inverter, a power adjustment decision is generated to adjust the inverter output power. The specific formula is Reduce the output power of the next monitoring segment The power size, The preset power conversion coefficient can be formulated based on the historical data of the inverter and experience. From the formula, it can be seen that when the power impact value is larger, the output power needs to be reduced more, but the power cannot be reduced indefinitely, and the electric energy must be reasonably used. Therefore, a maximum output power that the system allows to be adjusted is set to limit the output power of the inverter to reasonably adjust the output power of the inverter. In this way, the current change and temperature change during the operation of the inverter can be analyzed to determine the impact of the output power on the inverter performance, and then the corresponding power adjustment can be made to ensure that the working performance of the inverter is not affected, thereby ensuring the normal output of power.

[0074] In the above technical solution, the monitoring time of the short segment can be determined according to the actual situation, and the set current affects the reference value. , the set temperature influence reference value is , the set temperature current affects the reference value , the maximum output power that the system allows to adjust And the power impact threshold preset in the system It can be determined based on historical work data combined with experience data.

[0075] As an embodiment of the present invention, photovoltaic power The acquisition method is:

[0076] At standard temperature And standard light intensity Measure the standard photovoltaic power of photovoltaic panels ;

[0077] Get the light intensity change curve within the monitoring section And the temperature change curve , so that through the formula Get the photovoltaic power generated ;

[0078] in, is the temperature influence coefficient.

[0079] Through the above technical solution, this implementation provides photovoltaic power The specific method of obtaining the energy is that the generated photovoltaic power will vary due to the influence of light intensity and temperature. Therefore, in order to obtain the photovoltaic power more accurately, the photovoltaic power is obtained at the standard temperature. And standard light intensity Measure the standard photovoltaic power of photovoltaic panels , and then obtain the light intensity change curve within the monitoring segment And the temperature change curve , so that through the formula Get the photovoltaic power generated , where It is the temperature influence coefficient, which can be obtained based on relevant data in big data, so that the light intensity and temperature can be corrected to make the obtained photovoltaic power more accurate.

[0080] As an embodiment of the present invention, the amount of electrical energy required by the load The acquisition method is:

[0081] According to the most recent period The load consumption changes of the same test section every day are used to determine the first load demand ;

[0082] The second load demand is determined based on the average load demand of the same period every year in the historical time m years. ;

[0083] Then through the formula Get the energy required by the load , as well as is the proportionality coefficient.

[0084] Through the above technical solution, this embodiment provides the electrical energy required by the load The specific method of obtaining is to first obtain the data based on the most recent period. The load consumption changes of the same test section every day are used to determine the first load demand For example, taking a month as a cycle, obtain the change of the load requirement under the same detection section every day, and formulate the first load demand according to the daily change; then determine the second load demand based on the average load demand of the same cycle every year in the historical time m years For example, obtain the load demand in the same detection segment in the same month of each year in the past six years, so as to obtain the average load demand and determine the second load demand , and then through the formula Get the energy required by the load ,in as well as It is a proportionality coefficient, which is formulated based on empirical data. By combining the recent load demand changes and the historical average load demand changes for comprehensive analysis, the electrical energy required by the load can be determined more accurately.

[0085] It should be noted that the calculation formulas and various parameters involved in the calculations in the present invention have been dimensionally processed in advance, and the process of dimensionless processing is well known in the industry and will not be described here.

[0086] The above contents are merely examples and explanations of the concept of the present invention. Those skilled in the art may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they shall all fall within the protection scope of the present invention.

Claims

1. A photovoltaic inverter intelligent control system, characterized in that: The control system comprises: A photovoltaic power generation module, the photovoltaic power generation module is used to generate corresponding photovoltaic power according to weather information within a predetermined time period; A load monitoring module, the load monitoring module is used to obtain the load power usage within a predetermined time period to determine the amount of power required by the load; An inverter control module, the inverter control module is used to determine the output power of the inverter according to the generated photovoltaic power and the power required by the load; The inverter control module is also provided with an inverter data acquisition unit, a data analysis and processing unit and an output power adjustment unit; The inverter data acquisition unit is used to obtain current change data information and temperature change data information of the photovoltaic inverter during operation; The data analysis and processing unit performs comprehensive processing and analysis based on the acquired data information, thereby generating a power impact value, and determines whether to generate a power adjustment decision based on the power impact value; an output power adjustment unit, wherein the output power adjustment unit adjusts the output power of the inverter after receiving the power adjustment decision; The method for generating the power adjustment decision is: obtaining the current I and temperature T changes of the inverter itself in the monitoring segment, thereby constructing the curve equations f(t I) and f(t T) of the current and time, and the temperature and time in the monitoring segment; By formula Calculate the power impact value R; The power impact value R obtained is compared with the power impact threshold R preset in the system. td To compare: When R>R td When , a power adjustment decision is generated; Among them, t a is the start time of the monitoring segment, t b To monitor the end time of a short segment, g is the set temperature and current influence standard function, I th is the reference value of the set current influence, T th is the set temperature influence reference value, IT th The current affects the reference value for the set temperature; The output power adjustment unit works as follows: after receiving the power adjustment decision, the output power adjustment unit uses the formula Reduce the output power of the next monitoring segment; Among them, P - The output power that the inverter needs to reduce, P max is the maximum output power that the system allows to adjust, and α is the preset power conversion coefficient.

2. A photovoltaic inverter intelligent control system according to claim 1, characterized in that: The method in which the inverter control module determines the output power of the inverter according to the generated photovoltaic power and the power required by the load is: Divide the scheduled time period into n monitoring segments, and obtain the photovoltaic power Q generated in each monitoring segment pv And each detection segment can determine the load required electrical energy Q load ; The photovoltaic power Q generated in each detection segment pv The energy required by the load is determined load To compare: When Q pv >Q load When , the output power of the monitoring segment is determined as P A , where P A =ω*(Q load +Q se ); When Q pv ≤Q load When , the output power of the monitoring segment is determined as P B , where P B =ω*(Q pv -Q se ); Where ω is the preset electric energy power conversion coefficient, Q se The energy lost by photovoltaic power.

3. A photovoltaic inverter intelligent control system according to claim 2, characterized in that: The photovoltaic power loss Q se The method to obtain it is: By formula The photovoltaic power loss Q is obtained se ; Among them, δ1 is the inverter conversion loss coefficient, δ2 is the photovoltaic power station line loss coefficient, m is the number of working equipment in the photovoltaic power station, and k∈(1,m), Y k is the working time of the kth working device, is the reference value of the working time of the kth working equipment, Q k The electrical energy required for the kth working device.

4. A photovoltaic inverter intelligent control system according to claim 2, characterized in that: The photovoltaic power Q pv The acquisition method is: At standard temperature And standard light intensity Measure the standard photovoltaic power of photovoltaic panels Obtain the light intensity change curve Lc(t) and temperature change curve Tc(t) in the monitoring segment, and then use the formula The generated photovoltaic power Q pv ; Where μ is the temperature influence coefficient.

5. A photovoltaic inverter intelligent control system according to claim 2, characterized in that: The load requires electrical energy Q load The acquisition method is: Determine the first load demand based on the load consumption change of the same detection segment every day within the most recent period ΔT The second load demand is determined based on the average load demand of the same period every year in the historical time m years. Then through the formula The energy Q required by the load is obtained load , τ1 and τ2 are proportional coefficients.

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