CN109991470A - A kind of determination method and system of string type photovoltaic DC-to-AC converter transfer efficiency - Google Patents
A kind of determination method and system of string type photovoltaic DC-to-AC converter transfer efficiency Download PDFInfo
- Publication number
- CN109991470A CN109991470A CN201910132699.XA CN201910132699A CN109991470A CN 109991470 A CN109991470 A CN 109991470A CN 201910132699 A CN201910132699 A CN 201910132699A CN 109991470 A CN109991470 A CN 109991470A
- Authority
- CN
- China
- Prior art keywords
- power
- performance number
- converter
- side power
- string type
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R21/00—Arrangements for measuring electric power or power factor
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
- G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
Abstract
A kind of determination method of string type photovoltaic DC-to-AC converter transfer efficiency, comprising: all DC side power that will acquire based on the corresponding moment are fitted with side power is exchanged, and obtain matched curve；Based on the rated power of the string type photovoltaic DC-to-AC converter, selection exchange side performance number；And it is based on exchange side performance number, DC side performance number is calculated in conjunction with the matched curve；Based on the exchange side performance number and DC side performance number, the AC-DC conversion efficiency of the string type photovoltaic DC-to-AC converter is obtained.Scheme provided by the invention, the alternating current-direct current side power of string type photovoltaic DC-to-AC converter is fitted using quadratic polynomial, corresponding power-efficient point is found in matched curve again, the situation that solve photovoltaic DC-to-AC converter DC side not reciprocity with the performance number for exchanging side, efficiency evaluation precision is improved, the vacancy problem in terms of the open air operating analysis of current string type photovoltaic DC-to-AC converter and evaluation method has been filled up.
Description
Technical field
The present invention relates to photovoltaic DC-to-AC converter efficiency test fields, and in particular to a kind of string type photovoltaic DC-to-AC converter transfer efficiency
Determination method and system.
Background technique
The advantages of string type inverter, is that module difference and shadow occlusion are not influenced between by group string for it, reduce photovoltaic electric
Pond component best operating point and the unmatched situation of inverter, utmostly increase generated energy.
In string type photovoltaic DC-to-AC converter, in order to successfully manage group the influence of inconsistency and shadow occlusion between string, usually
Converge in DC side without outside, uses multichannel MPPT maximum power point tracking module (Maximum Power Point in inverter internal
Tracking abbreviation MPPT), every road MPPT module can access 2~4 optical crosstalk volt group strings, after the conditioning of MPPT module, then carry out inverse
Become.Therefore, when to string type photovoltaic DC-to-AC converter effect assessment, the uncertainty of itself photovoltaic group string causes photovoltaic inversion
The device DC side situation not reciprocity with the performance number for exchanging side.The efficiency rating of string type photovoltaic DC-to-AC converter not only with inverter itself
Performance is related, and also related to inverter territory of use irradiation resource, inverter is during 24 hour operation, by live weather ring
Border, Array Design etc. influence, curent change range is also larger, aggravated photovoltaic DC-to-AC converter DC side with exchange the performance number of side
Not reciprocity situation, the inaccuracy for causing string type photovoltaic DC-to-AC converter efficiency to test and assess.
Summary of the invention
For the not reciprocity feelings of the performance number for solving the photovoltaic DC-to-AC converter DC side in the presence of the prior art with exchanging side
Condition causes the problem of string type photovoltaic DC-to-AC converter efficiency assessment inaccuracy, and the present invention provides a kind of string type photovoltaic DC-to-AC converters
The determination method and system of transfer efficiency.
Present invention provide the technical scheme that a kind of determination method of string type photovoltaic DC-to-AC converter transfer efficiency, comprising:
All DC side power that will acquire based on the corresponding moment are fitted with side power is exchanged, and obtain matched curve；
Based on the rated power of the string type photovoltaic DC-to-AC converter, selection exchange side performance number；And it is based on the exchange side
Performance number calculates DC side performance number in conjunction with the matched curve；
Based on the exchange side performance number and DC side performance number, the alternating current-direct current for obtaining the string type photovoltaic DC-to-AC converter turns
Change efficiency.
Preferably, all DC side power that will acquire based on the corresponding moment are fitted with side power is exchanged, and are obtained
To matched curve, comprising:
According to setpoint frequency acquisition DC side power and exchange side power, and based on constantly will the correspondence moment DC side function
Rate with exchange side power by data group form store into the first data acquisition system；
Based on first data acquisition system, judge whether the DC side power in each data group judgement is less than exchange side function
Rate；
If the DC side power is less than exchange side power, the data group is stored to the second data set；
Otherwise, the data group is abandoned；
Matched curve is obtained by least square method based on the second data set.
Preferably, the rated power based on the string type photovoltaic DC-to-AC converter, selection exchange side performance number, comprising:
Based on the rated power of the inverter, multiple working conditions are selected；
Based on each working condition, corresponding exchange side performance number is determined.
Preferably, the working condition, comprising:
0.05 times of rated operation, 0.1 times of rated operation, 0.2 times of rated operation, 0.3 times of nominal operation
State, 0.5 times of rated operation, 0.75 times of rated operation and 1 times of rated operation.
Preferably, described to be based on exchange side performance number, DC side performance number, packet are calculated in conjunction with the matched curve
It includes:
Obtain the maximum power of the matched curve coefficient and the string type photovoltaic DC-to-AC converter；
Side performance number is exchanged with what is determined based on the working condition based on the matched curve coefficient, with the string type
The maximum power of photovoltaic DC-to-AC converter is constraint condition, seeks the corresponding DC side performance number of each exchange side performance number.
Preferably, the calculating formula of the DC side performance number, is shown below:
Wherein, Pdc2-kFor DC side performance number, Pac2-kFor exchange side performance number, k=1,27；A, b, c are fitting
Curve coefficients；PmaxFor the maximum power of the string type formula photovoltaic DC-to-AC converter.
Preferably, the expression formula of the constraint condition is as follows:
Pdc2-k> 0 and Pdc2-k<Pmax；
Wherein, Pdc2-kFor DC side performance number, Pac2-kTo exchange side performance number, PmaxFor the string type formula photovoltaic inversion
The maximum power of device.
Preferably, described to be based on the exchange side performance number and DC side performance number, obtain the string type photovoltaic inversion
The AC-DC conversion efficiency of device, comprising:
Based on specific exchange side performance number and DC side performance number, the power points for obtaining the string type photovoltaic DC-to-AC converter turns
Change efficiency；
According to the power points transfer efficiency, the inverter transfer efficiency is calculated.
Preferably, the calculating formula of the power points transfer efficiency, is shown below:
Wherein, ηkFor power point efficiency, Pac2-kTo exchange side performance number, Pac2-kFor DC side performance number, k=1,
2···7。
Preferably, the calculating formula of the inverter transfer efficiency, is shown below:
η=αk*ηk
Wherein, η is inverter efficiency, αkFor power points weighting coefficient, ηkFor power point efficiency, k=1,27.
Preferably, described according to setpoint frequency acquisition DC side power and exchange side power, and be based on the moment when will be to correspondence
The DC side power at quarter with exchange side power by data group form store into the first data acquisition system, comprising:
The topological structure for obtaining the string type photovoltaic DC-to-AC converter determines the MPPT maximum power point tracking number of modules of DC side
Amount, and according to the MPPT maximum power point tracking module number, determine voltage range and current range；
Corresponding voltage, current sensor are selected according to the voltage range and current range, obtains voltage and current number
According to；
According to the voltage and current data, the photovoltaic DC-to-AC converter DC side power is sought, and acquires the DC side
Power corresponds to the exchange side power at moment, by the DC side power with exchange form storage of the side power by data group to first
In data acquisition system.
Preferably, the MPPT maximum power point tracking module number of the determining DC side, and according to the maximum power point with
Track module number, determines voltage range and current range, comprising:
The quantity of the maximum work tracking point module is obtained, and obtains the light on each maximal power tracing point module
Volt group string quantity, obtains the total quantity of the photovoltaic group string；
According to the total quantity of the photovoltaic group string multiplied by the component open-circuit voltage obtained in advance, voltage range is obtained；
According to the total quantity of the photovoltaic group string multiplied by the component short circuit current obtained in advance, current range is obtained.
A kind of determination system of string type photovoltaic DC-to-AC converter transfer efficiency, the system, comprising:
Module is formulated in matched curve: all DC side power that will acquire based on the corresponding moment are intended with side power is exchanged
It closes, obtains matched curve；
Performance number obtains module: the rated power based on the string type photovoltaic DC-to-AC converter, selection exchange side performance number；And
Based on exchange side performance number, DC side performance number is calculated in conjunction with the matched curve；
Efficiency calculation module: it is based on the exchange side performance number and DC side performance number, it is inverse to obtain the string type photovoltaic
Become the AC-DC conversion efficiency of device.
Preferably, module is formulated in the matched curve, comprising:
First data acquisition system acquisition submodule: according to setpoint frequency acquisition DC side power with exchange side power, and be based on
Moment is by the DC side power at corresponding moment and exchanges side power by the form storage of data group into the first data acquisition system；
Judging submodule: being based on first data acquisition system, judges whether is DC side power in the judgement of each data group
Less than exchange side power；
The second data set acquisition submodule: if the DC side power is less than exchange side power, by the number
It stores according to group to the second data set；Otherwise, the data group is abandoned；
Matched curve acquisition submodule: matched curve is obtained by least square method based on the second data set.
Preferably, the performance number obtains module, comprising:
Working condition selects submodule: the rated power based on the inverter selects multiple working conditions；
It exchanges side performance number acquisition submodule: being based on each working condition, determine corresponding exchange side performance number.
Compared with prior art, the invention has the benefit that a kind of string type photovoltaic DC-to-AC converter transfer efficiency of the present invention
Determination method, comprising: all DC side power that will acquire based on the corresponding moment are fitted with side power is exchanged, and are intended
Close curve；Based on the rated power of the string type photovoltaic DC-to-AC converter, selection exchange side performance number；And it is based on exchange side function
Rate value calculates DC side performance number in conjunction with the matched curve；Based on the exchange side performance number and DC side performance number, obtain
The AC-DC conversion efficiency of the string type photovoltaic DC-to-AC converter.Scheme provided by the invention, by the friendship of string type photovoltaic DC-to-AC converter
DC side power is fitted using quadratic polynomial, further according to the rated power of string type photovoltaic DC-to-AC converter, in matched curve
The alternating current-direct current power points of upper searching in the same time, eliminates interference of the invalid alternating current-direct current power points to transfer efficiency result, solves
The photovoltaic DC-to-AC converter DC side situation not reciprocity with the performance number for exchanging side, improves efficiency evaluation precision, has filled up current group
Vacancy problem in terms of the open air operating analysis of string data photovoltaic DC-to-AC converter and evaluation method.
Detailed description of the invention
Fig. 1 is the determination method flow diagram of string type photovoltaic DC-to-AC converter transfer efficiency of the invention；
Fig. 2 is concrete operations flow chart of the invention；
Fig. 3 is AC power and dc power scatter plot after test processes of the invention；
Fig. 4 is test matched curve of the invention.
Specific embodiment
For a better understanding of the present invention, the contents of the present invention are done further with example with reference to the accompanying drawings of the specification
Explanation.
Embodiment 1:
Fig. 1 is the determination method flow diagram of string type photovoltaic DC-to-AC converter transfer efficiency of the invention, as shown in the figure:
S1: all DC side power that will acquire based on the corresponding moment are fitted with side power is exchanged, and it is bent to obtain fitting
Line.
It is analyzed for string type photovoltaic DC-to-AC converter topological structure, determines its DC side MPPT module number, DC side
Voltage and current range is monitored for the input total current of each MPPT module of inverter, input voltage；
In photovoltaic system, photovoltaic module connects to form photovoltaic group string, and 2~4 road photovoltaic groups access string type afterwards in series and parallel
Inverter MPPT module improved, converged, inversion.Concrete operations flow chart as shown in Figure 2, according to photovoltaic module serial number
Amount, with series component quantity multiplied by component open-circuit voltage, can calculate DC side voltage of converter range, according to every road MPPT module
Photovoltaic group string quantity is accessed, with photovoltaic group string quantity multiplied by the short circuit current on photovoltaic group string nameplate, it is straight to calculate photovoltaic DC-to-AC converter
Side current range is flowed, the sensor of covering electric current, voltage range is chosen；Side output voltage, electric current are exchanged according to photovoltaic DC-to-AC converter
The sensor of selection covering voltage and current range；
Suitable voltage, current sensor are installed at inverter alternating current-direct current side, and test signal is transmitted to data and is adopted
Acquisition means handle test data；
Setting testing time section is Tn, and each testing time point is ti, wherein i from 1,2,3 ... n
In data acquisition device, the power of each MPPT module of string type inverter synchronization DC side is carried out tired
Add, obtains inverter direct-flow side general power Pdc1-i；
In data acquisition device, the inverter ac side power P ac1-i of Pdc1-i phase in the same time, obtained survey are obtained
AC power and dc power scatter plot are as shown in Figure 3 after examination processing；
DC side power P dc1-i is judged with side power P ac1-i is exchanged, as Pdc1-i < Pac1-i, rejecting should
Group data, as Pdc1-i < Pac1-i, by DC side power with exchange side power (Pdc-j, Pac-j) in the form of data group
Store new data acquisition system.After each judgement, i increases by 1 automatically, until i >=n, jumps out and loops to determine；
Using following quadratic polynomial, the element in data acquisition system is fitted:
Curve matching coefficient a, b, c are determined according to least square method, and it is as shown in Figure 4 to obtain matched curve.
S2: the rated power based on the string type photovoltaic DC-to-AC converter, selection exchange side performance number；And it is based on the exchange
Side performance number calculates DC side performance number in conjunction with the matched curve.
Based on the rated power of the inverter, multiple working conditions are selected；Based on each working condition, determine corresponding
Exchange side performance number: according to inverter rated power Pnom, in matched curve select 0.05Pnom, 0.10Pnom,
Each power points of 0.20Pnom, 0.30Pnom, 0.50Pnom, 0.75Pnom and Pnom, as exchange side power P ac2-k, wherein k
It is 1,2,3 ... ... 7；
According to exchange side power P ac2-k and matched curve, DC side power P dc2-k is calculated, wherein k 1,2,
3 ... ... 7；
Wherein, Pdc2-k can generate two roots in solution procedure, seek the boundary condition of unique solution are as follows:
Pdc2-k>0 and Pdc2-k<Pmax；Pmax is photovoltaic DC-to-AC converter maximum power.
S3: being based on the exchange side performance number and DC side performance number, and the friendship for obtaining the string type photovoltaic DC-to-AC converter is straight
Flow transfer efficiency.
According to Pdc2-k and Pac2-k, photovoltaic DC-to-AC converter efficiency eta k on each point is calculated, wherein k 1,2,3 ... ...
7:
Each certain power point efficiency of inverter is counted according to photovoltaic DC-to-AC converter testing standard CGC/GF 035:2013
It calculates, in conjunction with each power points weighting coefficient α k, (wherein, 1,2,3 k ... ... 7), is assessed inverter efficiency η.
η=αk*ηk
Embodiment two:
Based on invention thought of the same race, system is determined the present invention also provides a kind of string type photovoltaic DC-to-AC converter transfer efficiency
System, comprising:
Module is formulated in matched curve: all DC side power that will acquire based on the corresponding moment are intended with side power is exchanged
It closes, obtains matched curve；
Performance number obtains module: the rated power based on the string type photovoltaic DC-to-AC converter, selection exchange side performance number；And
Based on exchange side performance number, DC side performance number is calculated in conjunction with the matched curve；
Efficiency calculation module: it is based on the exchange side performance number and DC side performance number, it is inverse to obtain the string type photovoltaic
Become the AC-DC conversion efficiency of device.
Module is formulated in the matched curve, comprising:
First data acquisition system acquisition submodule: according to setpoint frequency acquisition DC side power with exchange side power, and be based on
Moment is by the DC side power at corresponding moment and exchanges side power by the form storage of data group into the first data acquisition system；
Judging submodule: being based on first data acquisition system, judges whether is DC side power in the judgement of each data group
Less than exchange side power；
The second data set acquisition submodule: if the DC side power is less than exchange side power, by the number
It stores according to group to the second data set；Otherwise, the data group is abandoned；
Matched curve acquisition submodule: matched curve is obtained by least square method based on the second data set.
The performance number obtains module, comprising:
Working condition selects submodule: the rated power based on the inverter selects multiple working conditions；
It exchanges side performance number acquisition submodule: being based on each working condition, determine corresponding exchange side performance number.
The working condition of the working condition submodule selection, comprising:
0.05 times of rated operation, 0.1 times of rated operation, 0.2 times of rated operation, 0.3 times of nominal operation
State, 0.5 times of rated operation, 0.75 times of rated operation and 1 times of rated operation.
Exchange side performance number acquisition submodule, comprising:
Maximum power acquiring unit: the maximum work of the matched curve coefficient and the string type photovoltaic DC-to-AC converter is obtained
Rate；
DC side performance number acquiring unit: it is exchanged based on the matched curve coefficient with what is determined based on the working condition
It is corresponding to seek each exchange side performance number using the maximum power of the string type photovoltaic DC-to-AC converter as constraint condition for side performance number
DC side performance number.
The DC side performance number acquiring unit is calculate by the following formula the DC side performance number:
Wherein, Pdc2-kFor DC side performance number, Pac2-kFor exchange side performance number, k=1,27；A, b, c are fitting
Curve coefficients；PmaxFor the maximum power of the string type formula photovoltaic DC-to-AC converter.
The expression formula of constraint condition in the DC side performance number acquiring unit is as follows:
Pdc2-k> 0 and Pdc2-k<Pmax；
Wherein, Pdc2-kFor DC side performance number, Pac2-kTo exchange side performance number, PmaxFor the string type formula photovoltaic inversion
The maximum power of device.
The efficiency calculation module, comprising:
Power points transfer efficiency computational submodule: being based on specific exchange side performance number and DC side performance number, obtains described
The power points transfer efficiency of string type photovoltaic DC-to-AC converter；
Inverter transfer efficiency computational submodule: according to the power points transfer efficiency, the inverter conversion effect is calculated
Rate.
Power points transfer efficiency is calculate by the following formula in the power points transfer efficiency computational submodule:
Wherein, ηkFor power point efficiency, Pac2-kTo exchange side performance number, Pac2-kFor DC side performance number, k=1,
2···7。
The inverter transfer efficiency computational submodule is calculate by the following formula inverter transfer efficiency:
η=αk*ηk
Wherein, η is inverter efficiency, αkFor power points weighting coefficient, ηkFor power point efficiency, k=1,27.
The first data acquisition system acquisition submodule, comprising:
Electric current and voltage range determination unit: the topological structure of the string type photovoltaic DC-to-AC converter is obtained, determines DC side
MPPT maximum power point tracking module number determine voltage range and electric current and according to the MPPT maximum power point tracking module number
Range；
Electric current and voltage data determination unit: corresponding voltage, electric current are selected according to the voltage range and current range
Sensor obtains voltage and current data；
Data group storage unit: according to the voltage and current data, seeking the photovoltaic DC-to-AC converter DC side power, and
Acquire the exchange side power that the DC side power corresponds to the moment, by the DC side power with exchange side power by data group
Form is stored into the first data acquisition system.
The electric current and voltage range determination unit, comprising:
Photovoltaic group string quantity confirms subelement: obtaining the quantity of the maximum work tracking point module, and obtains each described
Photovoltaic group string quantity on maximal power tracing point module, obtains the total quantity of the photovoltaic group string；
Voltage range confirms subelement: according to the total quantity of the photovoltaic group string multiplied by the component open circuit electricity obtained in advance
Pressure, obtains voltage range；
Current range confirms subelement: according to the total quantity of the photovoltaic group string multiplied by the component short circuit electricity obtained in advance
Stream, obtains current range.
Obviously, described embodiments are some of the embodiments of the present invention, instead of all the embodiments.Based on the present invention
In embodiment, all other implementation obtained by those of ordinary skill in the art without making creative efforts
Example, shall fall within the protection scope of the present invention.
It should be understood by those skilled in the art that, embodiments herein can provide as method, system or computer program
Product.Therefore, complete hardware embodiment, complete software embodiment or reality combining software and hardware aspects can be used in the application
Apply the form of example.Moreover, it wherein includes the computer of computer usable program code that the application, which can be used in one or more,
The computer program implemented in usable storage medium (including but not limited to magnetic disk storage, CD-ROM, optical memory etc.) produces
The form of product.
The application is referring to method, the process of equipment (system) and computer program product according to the embodiment of the present application
Figure and/or block diagram describe.It should be understood that every one stream in flowchart and/or the block diagram can be realized by computer program instructions
The combination of process and/or box in journey and/or box and flowchart and/or the block diagram.It can provide these computer programs
Instruct the processor of general purpose computer, special purpose computer, Embedded Processor or other programmable data processing devices to produce
A raw machine, so that being generated by the instruction that computer or the processor of other programmable data processing devices execute for real
The device for the function of being specified in present one or more flows of the flowchart and/or one or more blocks of the block diagram.
These computer program instructions, which may also be stored in, is able to guide computer or other programmable data processing devices with spy
Determine in the computer-readable memory that mode works, so that it includes referring to that instruction stored in the computer readable memory, which generates,
Enable the manufacture of device, the command device realize in one box of one or more flows of the flowchart and/or block diagram or
The function of being specified in multiple boxes.
These computer program instructions also can be loaded onto a computer or other programmable data processing device, so that counting
Series of operation steps are executed on calculation machine or other programmable devices to generate computer implemented processing, thus in computer or
The instruction executed on other programmable devices is provided for realizing in one or more flows of the flowchart and/or block diagram one
The step of function of being specified in a box or multiple boxes.
The above is only the embodiment of the present invention, are not intended to restrict the invention, all in the spirit and principles in the present invention
Within, any modification, equivalent substitution, improvement and etc. done, be all contained in apply pending scope of the presently claimed invention it
It is interior.
Claims (15)
1. a kind of determination method of string type photovoltaic DC-to-AC converter transfer efficiency characterized by comprising
All DC side power that will acquire based on the corresponding moment are fitted with side power is exchanged, and obtain matched curve；
Based on the rated power of the string type photovoltaic DC-to-AC converter, selection exchange side performance number；And it is based on exchange side power
Value calculates DC side performance number in conjunction with the matched curve；
Based on the exchange side performance number and DC side performance number, the AC-DC conversion effect of the string type photovoltaic DC-to-AC converter is obtained
Rate.
2. the method as described in claim 1, which is characterized in that all DC side power that will acquire based on the corresponding moment
It is fitted with side power is exchanged, obtains matched curve, comprising:
According to setpoint frequency acquisition DC side power and exchange side power, and based on constantly by the DC side power at correspondence moment with
Side power is exchanged to store by the form of data group into the first data acquisition system；
Based on first data acquisition system, judge whether the DC side power in each data group judgement is less than exchange side power；
If the DC side power is less than exchange side power, the data group is stored to the second data set；Otherwise,
Abandon the data group；
Matched curve is obtained by least square method based on the second data set.
3. the method as described in claim 1, which is characterized in that the specified function based on the string type photovoltaic DC-to-AC converter
Rate, selection exchange side performance number, comprising:
Based on the rated power of the string type photovoltaic DC-to-AC converter, multiple working conditions are selected；
Based on each working condition, corresponding exchange side performance number is determined.
4. method as claimed in claim 3, which is characterized in that the working condition, comprising:
0.05 times of rated operation, 0.1 times of rated operation, 0.2 times of rated operation, 0.3 times of rated operation,
0.5 times of rated operation, 0.75 times of rated operation and 1 times of rated operation.
5. method as claimed in claim 3, which is characterized in that it is described to be based on exchange side performance number, in conjunction with the fitting
Curve calculates DC side performance number, comprising:
Obtain the maximum power of the matched curve coefficient and the string type photovoltaic DC-to-AC converter；
Side performance number is exchanged with what is determined based on the working condition based on the matched curve coefficient, with the string type photovoltaic
The maximum power of inverter is constraint condition, seeks the corresponding DC side performance number of each exchange side performance number.
6. method as claimed in claim 5, which is characterized in that the calculating formula of the DC side performance number is shown below:
Wherein, Pdc2-kFor DC side performance number, Pac2-kFor exchange side performance number, k=1,27；A, b, c are matched curve
Coefficient；PmaxFor the maximum power of the string type formula photovoltaic DC-to-AC converter.
7. method as claimed in claim 6, which is characterized in that the expression formula of the constraint condition is as follows:
Pdc2-k> 0 and Pdc2-k<Pmax；
Wherein, PmaxFor the maximum power of the string type photovoltaic DC-to-AC converter.
8. the method as described in claim 1, which is characterized in that described to be based on the exchange side performance number and DC side power
Value, obtains the AC-DC conversion efficiency of the string type photovoltaic DC-to-AC converter, comprising:
Based on specific exchange side performance number and DC side performance number, the power points conversion effect of the string type photovoltaic DC-to-AC converter is obtained
Rate；
According to the power points transfer efficiency, the inverter transfer efficiency is calculated.
9. method according to claim 8, which is characterized in that the calculating formula of the power points transfer efficiency is shown below:
Wherein, ηkFor power point efficiency, Pac2-kTo exchange side performance number, Pac2-kFor DC side performance number,k=1,27.
10. method according to claim 8, which is characterized in that the calculating formula of the inverter transfer efficiency, such as following formula institute
Show:
η=0k*ηk
Wherein, η is inverter efficiency, αkFor power points weighting coefficient, ηkFor power point efficiency, k=1,27.
11. method according to claim 2, which is characterized in that it is described according to setpoint frequency acquisition DC side power with exchange
Side power, and based on constantly by the DC side power at corresponding moment and exchange side power store by the form of data group it is several to first
According in set, comprising:
The topological structure for obtaining the string type photovoltaic DC-to-AC converter determines the MPPT maximum power point tracking module number of DC side, and
According to the MPPT maximum power point tracking module number, voltage range and current range are determined；
Corresponding voltage, current sensor are selected according to the voltage range and current range, obtains voltage and current data；
According to the voltage and current data, the photovoltaic DC-to-AC converter DC side power is sought, and acquires the DC side power
The exchange side power at corresponding moment by the DC side power and exchanges side power and stores by the form of data group to the first data
In set.
12. method as claimed in claim 11, which is characterized in that the MPPT maximum power point tracking number of modules of the determining DC side
Amount, and according to the MPPT maximum power point tracking module number, determine voltage range and current range, comprising:
The quantity of the maximum work tracking point module is obtained, and obtains the photovoltaic group on each maximal power tracing point module
String quantity, obtains the total quantity of the photovoltaic group string；
According to the total quantity of the photovoltaic group string multiplied by the component open-circuit voltage obtained in advance, voltage range is obtained；
According to the total quantity of the photovoltaic group string multiplied by the component short circuit current obtained in advance, current range is obtained.
13. a kind of determination system of string type photovoltaic DC-to-AC converter transfer efficiency, which is characterized in that the system, comprising:
Module is formulated in matched curve: all DC side power that will acquire based on the corresponding moment are fitted with side power is exchanged,
Obtain matched curve；
Performance number obtains module: the rated power based on the string type photovoltaic DC-to-AC converter, selection exchange side performance number；And it is based on
Exchange side performance number calculates DC side performance number in conjunction with the matched curve；
Efficiency calculation module: it is based on the exchange side performance number and DC side performance number, obtains the string type photovoltaic DC-to-AC converter
AC-DC conversion efficiency.
14. system as claimed in claim 13, which is characterized in that module is formulated in the matched curve, comprising:
First data acquisition system acquisition submodule: according to setpoint frequency acquisition DC side power and side power is exchanged, and based on the moment
By the DC side power at corresponding moment and side power is exchanged by the form storage of data group into the first data acquisition system；
Judging submodule: being based on first data acquisition system, judges whether the DC side power in each data group judgement is less than
Exchange side power；
The second data set acquisition submodule: if the DC side power is less than exchange side power, by the data group
It stores to the second data set；Otherwise, the data group is abandoned；
Matched curve acquisition submodule: matched curve is obtained by least square method based on the second data set.
15. system as claimed in claim 13, which is characterized in that the performance number obtains module, comprising:
Working condition selects submodule: the rated power based on the inverter selects multiple working conditions；
It exchanges side performance number acquisition submodule: being based on each working condition, determine corresponding exchange side performance number.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910132699.XA CN109991470A (en) | 2019-02-22 | 2019-02-22 | A kind of determination method and system of string type photovoltaic DC-to-AC converter transfer efficiency |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910132699.XA CN109991470A (en) | 2019-02-22 | 2019-02-22 | A kind of determination method and system of string type photovoltaic DC-to-AC converter transfer efficiency |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN109991470A true CN109991470A (en) | 2019-07-09 |
Family
ID=67130270
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910132699.XA Pending CN109991470A (en) | 2019-02-22 | 2019-02-22 | A kind of determination method and system of string type photovoltaic DC-to-AC converter transfer efficiency |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109991470A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110940851A (en) * | 2019-11-18 | 2020-03-31 | 中电科仪器仪表(安徽)有限公司 | Power detection device and method for modular programmable photovoltaic system |
| CN111025060A (en) * | 2019-12-13 | 2020-04-17 | 中国科学院电工研究所 | Testing method of grid-connected inverse control all-in-one machine |
| CN111273109A (en) * | 2020-03-18 | 2020-06-12 | 珠海格力电器股份有限公司 | Energy conversion efficiency testing method and device and power utilization system |
| CN114035099A (en) * | 2021-10-12 | 2022-02-11 | 深圳供电局有限公司 | Method and device for measuring AC/DC conversion efficiency and electronic equipment |
Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR101132323B1 (en) * | 2011-12-23 | 2012-04-06 | 주식회사 케이디파워 | Photovoltaic power generation system perform the maximum power point tracking about the unit group |
| US20130077366A1 (en) * | 2011-09-22 | 2013-03-28 | Kyoung Hwan Kim | Solar energy generation system tracking adaptive maximum power point and its method |
| CN103020766A (en) * | 2012-12-10 | 2013-04-03 | 上海电力设计院有限公司 | Photovoltaic power generation planning method for photovoltaic power generation system |
| CN103107557A (en) * | 2013-01-25 | 2013-05-15 | 华北电力大学 | Photovoltaic power station group control combinatorial optimization method |
| CN103744470A (en) * | 2014-01-25 | 2014-04-23 | 莱芜汇中能源科技有限公司 | Method for tracking maximum power point of inverter by golden section method |
| CN104362977A (en) * | 2014-11-06 | 2015-02-18 | 国家电网公司 | Photovoltaic inverter two-peak dynamic/static MPP tracking efficiency test method |
| CN104682436A (en) * | 2015-03-17 | 2015-06-03 | 成都鼎智汇科技有限公司 | Energy storage system micro-grid capable of inhibiting power fluctuation |
| KR101595060B1 (en) * | 2014-10-01 | 2016-02-17 | 한국에너지기술연구원 | Invert apparatus having a function of dynamic mppt and the dynamic mppt method thereof for solar generating system |
| CN105375878A (en) * | 2015-12-16 | 2016-03-02 | 中国科学院广州能源研究所 | Method for online detection and assessment of photovoltaic system |
| CN106099972A (en) * | 2016-05-20 | 2016-11-09 | 西安交通大学 | Parallel converters system effectiveness optimization method and current transformer operation/cutting method in microgrid |
| CN106814265A (en) * | 2015-11-27 | 2017-06-09 | 中国电力科学研究院 | A kind of photovoltaic DC-to-AC converter generating efficiency test system |
| CN108267951A (en) * | 2016-12-30 | 2018-07-10 | 南京理工大学 | A kind of maximum power point-tracing control method based on core offset minimum binary |
-
2019
- 2019-02-22 CN CN201910132699.XA patent/CN109991470A/en active Pending
Patent Citations (12)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20130077366A1 (en) * | 2011-09-22 | 2013-03-28 | Kyoung Hwan Kim | Solar energy generation system tracking adaptive maximum power point and its method |
| KR101132323B1 (en) * | 2011-12-23 | 2012-04-06 | 주식회사 케이디파워 | Photovoltaic power generation system perform the maximum power point tracking about the unit group |
| CN103020766A (en) * | 2012-12-10 | 2013-04-03 | 上海电力设计院有限公司 | Photovoltaic power generation planning method for photovoltaic power generation system |
| CN103107557A (en) * | 2013-01-25 | 2013-05-15 | 华北电力大学 | Photovoltaic power station group control combinatorial optimization method |
| CN103744470A (en) * | 2014-01-25 | 2014-04-23 | 莱芜汇中能源科技有限公司 | Method for tracking maximum power point of inverter by golden section method |
| KR101595060B1 (en) * | 2014-10-01 | 2016-02-17 | 한국에너지기술연구원 | Invert apparatus having a function of dynamic mppt and the dynamic mppt method thereof for solar generating system |
| CN104362977A (en) * | 2014-11-06 | 2015-02-18 | 国家电网公司 | Photovoltaic inverter two-peak dynamic/static MPP tracking efficiency test method |
| CN104682436A (en) * | 2015-03-17 | 2015-06-03 | 成都鼎智汇科技有限公司 | Energy storage system micro-grid capable of inhibiting power fluctuation |
| CN106814265A (en) * | 2015-11-27 | 2017-06-09 | 中国电力科学研究院 | A kind of photovoltaic DC-to-AC converter generating efficiency test system |
| CN105375878A (en) * | 2015-12-16 | 2016-03-02 | 中国科学院广州能源研究所 | Method for online detection and assessment of photovoltaic system |
| CN106099972A (en) * | 2016-05-20 | 2016-11-09 | 西安交通大学 | Parallel converters system effectiveness optimization method and current transformer operation/cutting method in microgrid |
| CN108267951A (en) * | 2016-12-30 | 2018-07-10 | 南京理工大学 | A kind of maximum power point-tracing control method based on core offset minimum binary |
Non-Patent Citations (3)
| Title |
|---|
| 包斯嘉等: "光伏发电效率检测方法研究及案例分析", 《电气自动化》, vol. 38, no. 4, pages 59 - 61 * |
| 王林成: "微热管阵列光伏光热组件瞬时效率实验研究", 《太阳能学报》, vol. 36, no. 3, pages 539 - 545 * |
| 陆晓楠等: "适用于光伏发电系统的混合级联式逆变器", 清华大学学报(自然科学版), vol. 51, no. 3, pages 351 - 355 * |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110940851A (en) * | 2019-11-18 | 2020-03-31 | 中电科仪器仪表(安徽)有限公司 | Power detection device and method for modular programmable photovoltaic system |
| CN111025060A (en) * | 2019-12-13 | 2020-04-17 | 中国科学院电工研究所 | Testing method of grid-connected inverse control all-in-one machine |
| CN111273109A (en) * | 2020-03-18 | 2020-06-12 | 珠海格力电器股份有限公司 | Energy conversion efficiency testing method and device and power utilization system |
| CN111273109B (en) * | 2020-03-18 | 2021-03-12 | 珠海格力电器股份有限公司 | Energy conversion efficiency testing method and device and power utilization system |
| CN114035099A (en) * | 2021-10-12 | 2022-02-11 | 深圳供电局有限公司 | Method and device for measuring AC/DC conversion efficiency and electronic equipment |
| CN114035099B (en) * | 2021-10-12 | 2023-12-22 | 深圳供电局有限公司 | Method and device for measuring alternating-current/direct-current conversion efficiency and electronic equipment |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109991470A (en) | A kind of determination method and system of string type photovoltaic DC-to-AC converter transfer efficiency | |
| CA2840896C (en) | Methods and systems for determining an association between nodes and phases via a smart grid | |
| CN110633744B (en) | Region identification method for intelligent electric meter | |
| KR101221083B1 (en) | Method for assume condition of power distribution System | |
| CN102377180B (en) | Power system load modeling method based on electric energy quality monitoring system | |
| CN104836256B (en) | The method and system that a kind of power distribution network photovoltaic digestion capability calculates | |
| WO2018022134A1 (en) | Electrical energy storage system with battery resistance estimation | |
| CN110659693B (en) | K-nearest neighbor classification-based power distribution network rapid topology identification method, system and medium | |
| CN110070282A (en) | A kind of low-voltage platform area line loss analysis of Influential Factors method based on Synthesis Relational Grade | |
| CN106548410B (en) | Method for evaluating voltage unbalance probability of power distribution network containing distributed power supply | |
| CN115065053B (en) | Station area harmonic responsibility qualitative assessment method and system based on source-load equivalent admittance | |
| CN112994097A (en) | High-proportion distributed photovoltaic cooperative control method based on intelligent distribution transformer terminal system | |
| Kardos et al. | Complete results for a numerical evaluation of interior point solvers for large-scale optimal power flow problems | |
| Huang et al. | An efficient probabilistic approach based on area grey incidence decision making for optimal distributed generation planning | |
| CN113239512A (en) | Toughness-considered screening method and system for AC/DC power distribution network planning scheme | |
| CN108039720A (en) | A kind of definite method and apparatus of alternating current-direct current combined hybrid system total transfer capability | |
| CN106408206B (en) | A kind of distribution network reliability evaluation method constituting micro-capacitance sensor containing photovoltaic power generation | |
| CN106021754B (en) | Consider the serial-parallel power grid Probabilistic Load Flow algorithm of VSC reactive power constraints adjustable strategies | |
| CN106054665B (en) | A kind of large-scale photovoltaic inverter system divides group's equivalent modeling method | |
| CN105701265A (en) | Double-fed wind generator modeling method and apparatus | |
| CN110112747B (en) | Power distribution network voltage control method and system based on synchronous measurement and sensitivity estimation | |
| Zhang et al. | Stability constrained optimal power flow for the balancing market using genetic algorithms | |
| CN110460085A (en) | A method of consider wind-powered electricity generation and part throttle characteristics to effect on power system | |
| CN110336322A (en) | Method is determined based on the photovoltaic power generation allowed capacity of day minimum load confidence interval | |
| Bozorg et al. | Model-less/Measurement-based computation of voltage sensitivities in unbalanced electrical distribution networks: experimental validation |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |