CN109728597A - A kind of low voltage ride through of photovoltaic inverter property fitting method and system - Google Patents
A kind of low voltage ride through of photovoltaic inverter property fitting method and system Download PDFInfo
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Abstract
The present invention provides a kind of low voltage ride through of photovoltaic inverter property fitting method and system, passes through test including the low voltage failure according to setting and obtains electrical quantity, and verifies the consistency of the identical test electrical quantity that homogeneous is not tested；Critical electrical amount, which is chosen, according to the consistency of electrical quantity carries out low voltage crossing feature fitting；The electrical quantity includes: the watt current steady-state value and reactive current steady-state value in front of the voltage steady-state value in front of low voltage failure and low voltage failure stable state section, low voltage failure and low voltage failure stable state section, low voltage failure restore during electric current regeneration rate.Technical solution provided by the invention, it is easy to operate, be easily achieved, versatility it is good, can accurately be fitted the low voltage crossing external characteristics of inverter, convenient for promote.
Description
Technical field
The invention belongs to field of power systems, and in particular to a kind of low voltage ride through of photovoltaic inverter property fitting method and
System.
Background technique
Photovoltaic power generation scale development is rapid, as capacity of the photovoltaic plant in power grid is increasing, grasps inverter
Influence of the low voltage crossing characteristic for analysis photovoltaic plant to power grid has great importance.
Active reactive independent control may be implemented in photovoltaic DC-to-AC converter, and rapid dynamic response speed is the core of photovoltaic generating system
Feel concerned about system.Inverter is typical power electronic system, different from conventional electric generators, the grid-connected characteristic of inverter be primarily not by
The physical structure of inverter itself determines, but is controlled by it device and parameter determines.Analyze inverter low voltage crossing characteristic
It is typical " cinder box " problem.In Practical Project, various brands inverter generallys use similar circuit topology and control structure,
But specific control strategy and parameter are different, and not external disclosures.Lack control strategy and parameter according to mechanism analysis method, only
Lack necessary theory analysis again using method of testing.In tactful different, the limited situation of known conditions, it is necessary to study one kind
Versatility is good, low voltage crossing property fitting method convenient for popularization.
Summary of the invention
The present invention proposes a kind of low voltage ride through of photovoltaic inverter property fitting method and system, is existed by calculating inverter
Transient response critical electrical amount during low voltage crossing, to meet the needs of fitting low voltage ride through of photovoltaic inverter characteristic.
The present invention provides a kind of low voltage ride through of photovoltaic inverter property fitting method, comprising:
Test is passed through according to the low voltage failure of setting and obtains electrical quantity, and is verified identical not homogeneous of testing and tested to obtain
Electrical quantity consistency；
Critical electrical amount, which is chosen, according to the consistency of electrical quantity carries out low voltage crossing feature fitting；
The electrical quantity include: the voltage steady-state value in front of low voltage failure and low voltage failure stable state section, low-voltage therefore
Before barrier and during the watt current steady-state value in low voltage failure stable state section and reactive current steady-state value, low voltage failure recovery
Electric current regeneration rate.
It is described to include: according to the consistency of electrical quantity selection critical electrical amount
It chooses the voltage steady-state value absolute value of the bias that homogeneous is not tested and is less than 0.05pu, watt current and reactive current
Electric current regeneration rate absolute value of the bias during steady-state value absolute value of the bias is less than 0.1pu, low voltage failure restores is less than
The electrical quantity of the test of 0.2pu/s is critical electrical amount.
Feature during feature fitting and low-voltage are restored during the low voltage crossing feature fitting includes: low voltage failure
Fitting.
Feature fitting includes: during the low voltage failure
The reactive current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage；
The watt current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage.
The reactive current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage as the following formula:
Iq=min (Kq_LV(ULV-Uterm)+KIq0_flagIq0+Iq0_LV,Iqmax_LV)
In formula, IqFor the reactive current steady-state value in low voltage failure stable state section, Kq_LVFor reactive current support coefficient, ULV
For the voltage threshold for entering low voltage failure, UtermTo exchange side voltage, KIq0_flagMark coefficient, I are superimposed for reactive currentq0
For the reactive current steady-state value before low voltage failure, Iq0_LVFor the reactive current initial value of low voltage failure, Iqmax_LVFor low electricity
Press the maximum reactive current in failure stable state section.
Reactive current steady-state value I before the low voltage failureq0Calculation formula it is as follows:
In formula, iq0Indicate the reactive current value in low voltage failure presteady state section, Kiq0StartIt is steady before expression low voltage failure
The data sequence number of state section start time, Kiq0EndIndicate the data sequence number of low voltage failure presteady state section finish time.
The reactive current steady-state value I in low voltage failure stable state sectionqCalculation formula it is as follows:
I in formulaqIndicate the watt current value in low voltage failure stable state section, KiqStartIndicate low voltage failure stable state section
The data sequence number of start time, KiqEndIndicate the data sequence number of low voltage failure stable state section finish time.
The watt current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage as the following formula:
In formula, IpFor the watt current steady-state value in low voltage failure stable state section, P0It is active before low voltage failure to enter
Power, UtermTo exchange side voltage, Imax_FRTFor the maximum current in low voltage failure stable state section, IqIt is steady for low voltage failure
The reactive current in state section, Ip0For the watt current steady-state value before low voltage failure, Kp1_FRTAnd KP2_FRT is equalFor watt current system
Number, Ip0_FRTFor the watt current initial value of low voltage failure, Ip_Flag is the watt current clipping in low voltage failure stable state section
Flag bit.
Watt current steady-state value I before the low voltage failurep0Calculation formula it is as follows:
In formula, ip0Indicate the watt current value in low voltage failure presteady state section, Kip0StartIt is steady before expression low voltage failure
The data sequence number of state section start time, Kip0EndIndicate the data sequence number of low voltage failure presteady state section finish time.
The watt current steady-state value I in low voltage failure stable state sectionpCalculation formula it is as follows:
I in formulapIndicate the watt current value in low voltage failure stable state section, KipStartIndicate low voltage failure stable state section
The data sequence number of start time, KipEndIndicate the data sequence number of low voltage failure stable state section finish time.
Feature fitting includes: the flat of the electric current regeneration rate during calculating voltage ride-through recovery during the low-voltage is restored
Mean value.
The calculation formula of electric current regeneration rate during the low voltage failure recovery is as follows:
In formula, dIp_LVElectric current regeneration rate during restoring for low voltage failure, Ip_LV2Terminate for low voltage failure recovery
The watt current at moment, Ip_LV1Restore the watt current of start time, t for low voltage failurep_LV2Restore to tie for low voltage failure
Beam moment, tp_LV1Restore start time for low voltage failure.
It further include setting inverter initial launch operating condition before setting low voltage crossing test；
The operating condition includes high-power, mid power and small-power；
High-power operating condition refers to that inverter output power is the 70%~100% of rated power；
Mid power operating condition refers to that inverter output power is the 40%~60% of rated power；
Small-power operating condition refers to that inverter output power is the 10%~30% of rated power.
The setting low voltage crossing is tested
Drop to inverter ac side voltage respectively in the pre-set interval of voltage rating；
The pre-set interval of the voltage rating includes: 0~20%, 20%~30%, 50%~60% and 70%~90%.
The present invention provides a kind of low voltage ride through of photovoltaic inverter property fitting system, comprising:
Consistency module: passing through test according to the low voltage failure of setting and obtain electrical quantity, and verifies identical test not
The consistency for the electrical quantity that homogeneous is tested；
Fitting module: critical electrical amount is chosen according to the consistency of electrical quantity and carries out low voltage crossing feature fitting；
The electrical quantity include: the voltage steady-state value in front of low voltage failure and low voltage failure stable state section, low-voltage therefore
The preceding watt current steady-state value and reactive current steady-state value with low voltage failure stable state section of barrier, during low voltage failure restores
Electric current regeneration rate.
Feature fitting during feature fitting submodule and low-voltage are restored during the fitting module includes: low voltage failure
Submodule.
Feature fitting submodule includes: for by the idle electricity in low voltage failure stable state section during the low voltage failure
Stream steady-state value and the first fitting unit for carrying out curve fitting of voltage and for by the watt current in low voltage failure stable state section
The second fitting unit that steady-state value and voltage carry out curve fitting.
First fitting unit as the following formula carries out the reactive current steady-state value in low voltage failure stable state section and voltage
Curve matching:
Iq=min (Kq_LV(ULV-Uterm)+KIq0_flagIq0+Iq0_LV,Iqmax_LV)
In formula, IqFor the reactive current steady-state value in low voltage failure stable state section, Kq_LVFor reactive current support coefficient, ULV
For the voltage threshold for entering low voltage failure, UtermTo exchange side voltage, KIq0_flagMark coefficient, I are superimposed for reactive currentq0
For the reactive current steady-state value before low voltage failure, Iq0_LVFor the reactive current initial value of low voltage failure, Iqmax_LVFor low electricity
Press the maximum reactive current in failure stable state section.
Second fitting unit is as the following formula by the watt current steady-state value and voltage in low voltage failure stable state section
It carries out curve fitting:
In formula, IpFor the watt current steady-state value in low voltage failure stable state section, P0It is active before low voltage failure to enter
Power, UtermTo exchange side voltage, Imax_FRTFor the maximum current in low voltage failure stable state section, IqIt is steady for low voltage failure
The reactive current in state section, Ip0For the watt current steady-state value before low voltage failure, Kp1_FRTAnd KP2_FRT is equalFor watt current system
Number, Ip0_FRTFor the watt current initial value of low voltage failure, Ip_Flag is the watt current clipping in low voltage failure stable state section
Flag bit.
Compared with the latest prior art, technical solution provided by the invention has the advantages that
Technical solution provided by the invention, by calculating critical electrical amount of the inverter during low voltage crossing, with public affairs
Formula is fitted the low voltage crossing characteristic of different brands model inverter, with it is easy to operate, be easily achieved, that versatility is good is excellent
Point can accurately be fitted the low voltage crossing external characteristics of inverter, be a kind of practical engineering method convenient for popularization.
Detailed description of the invention
Fig. 1 is a kind of low voltage ride through of photovoltaic inverter property fitting method flow diagram of the present invention；
Fig. 2, which is that inverter is low in the embodiment of the present invention, wears test system schematic diagram；
Fig. 3 is the basic flow chart of inverter low voltage crossing property fitting in the embodiment of the present invention；
Fig. 4 is the comparison diagram of simulation value and actual measured value under high-power operating condition in the embodiment of the present invention；
Fig. 5 is the comparison diagram of simulation value and actual measured value under middle low power of embodiment of the present invention operating condition；
Specific embodiment
The present invention will be further described with reference to the accompanying drawing.
As shown in Figure 1, the present invention provides a kind of low voltage ride through of photovoltaic inverter property fitting method, comprising:
The present invention provides a kind of low voltage ride through of photovoltaic inverter property fitting method, comprising:
Test is passed through according to the low voltage failure of setting and obtains electrical quantity, and is verified identical not homogeneous of testing and tested to obtain
Electrical quantity consistency；
Critical electrical amount, which is chosen, according to the consistency of electrical quantity carries out low voltage crossing feature fitting；
The electrical quantity include: the voltage steady-state value in front of low voltage failure and low voltage failure stable state section, low-voltage therefore
Before barrier and during the watt current steady-state value in low voltage failure stable state section and reactive current steady-state value, low voltage failure recovery
Electric current regeneration rate.
It is described to include: according to the consistency of electrical quantity selection critical electrical amount
It chooses the voltage steady-state value absolute value of the bias that homogeneous is not tested and is less than 0.05pu, watt current and reactive current
Electric current regeneration rate absolute value of the bias during steady-state value absolute value of the bias is less than 0.1pu, low voltage failure restores is less than
The electrical quantity of the test of 0.2pu/s is critical electrical amount.
Feature during feature fitting and low-voltage are restored during the low voltage crossing feature fitting includes: low voltage failure
Fitting.
Feature fitting includes: during the low voltage failure
The reactive current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage；
The watt current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage.
The reactive current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage as the following formula:
Iq=min (Kq_LV(ULV-Uterm)+KIq0_flagIq0+Iq0_LV,Iqmax_LV)
In formula, IqFor the reactive current steady-state value in low voltage failure stable state section, Kq_LVFor reactive current support coefficient, ULV
For the voltage threshold for entering low voltage failure, UtermTo exchange side voltage, KIq0_flagMark coefficient, I are superimposed for reactive currentq0
For the reactive current steady-state value before low voltage failure, Iq0_LVFor the reactive current initial value of low voltage failure, Iqmax_LVFor low electricity
Press the maximum reactive current in failure stable state section.
Reactive current steady-state value I before the low voltage failureq0Calculation formula it is as follows:
In formula, iq0Indicate the reactive current value in low voltage failure presteady state section, Kiq0StartIt is steady before expression low voltage failure
The data sequence number of state section start time, Kiq0EndIndicate the data sequence number of low voltage failure presteady state section finish time.
The reactive current steady-state value I in low voltage failure stable state sectionqCalculation formula it is as follows:
I in formulaqIndicate the watt current value in low voltage failure stable state section, KiqStartIndicate low voltage failure stable state section
The data sequence number of start time, KiqEndIndicate the data sequence number of low voltage failure stable state section finish time.
The watt current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage as the following formula:
In formula, IpFor the watt current steady-state value in low voltage failure stable state section, P0It is active before low voltage failure to enter
Power, UtermTo exchange side voltage, Imax_FRTFor the maximum current in low voltage failure stable state section, IqIt is steady for low voltage failure
The reactive current in state section, Ip0For the watt current steady-state value before low voltage failure, Kp1_FRTAnd KP2_FRT is equalFor watt current system
Number, Ip0_FRTFor the watt current initial value of low voltage failure, Ip_Flag is the watt current clipping in low voltage failure stable state section
Flag bit.
Watt current steady-state value I before the low voltage failurep0Calculation formula it is as follows:
In formula, ip0Indicate the watt current value in low voltage failure presteady state section, Kip0StartIt is steady before expression low voltage failure
The data sequence number of state section start time, Kip0EndIndicate the data sequence number of low voltage failure presteady state section finish time.
The watt current steady-state value I in low voltage failure stable state sectionpCalculation formula it is as follows:
I in formulapIndicate the watt current value in low voltage failure stable state section, KipStartIndicate low voltage failure stable state section
The data sequence number of start time, KipEndIndicate the data sequence number of low voltage failure stable state section finish time.
Feature fitting includes: the flat of the electric current regeneration rate during calculating voltage ride-through recovery during the low-voltage is restored
Mean value.
The calculation formula of electric current regeneration rate during the low voltage failure recovery is as follows:
In formula, dIp_LVElectric current regeneration rate during restoring for low voltage failure, Ip_LV2Terminate for low voltage failure recovery
The watt current at moment, Ip_LV1Restore the watt current of start time, t for low voltage failurep_LV2Restore to tie for low voltage failure
Beam moment, tp_LV1Restore start time for low voltage failure.
It further include setting inverter initial launch operating condition before setting low voltage crossing test；
The operating condition includes high-power, mid power and small-power；
High-power operating condition refers to that inverter output power is the 70%~100% of rated power；
Mid power operating condition refers to that inverter output power is the 40%~60% of rated power；
Small-power operating condition refers to that inverter output power is the 10%~30% of rated power.
The setting low voltage crossing is tested
Drop to inverter ac side voltage respectively in the pre-set interval of voltage rating；
The pre-set interval of the voltage rating includes: 0~20%, 20%~30%, 50%~60% and 70%~90%.
The identical test electrical quantity that homogeneous is not tested is got over closer to the electrical quantity consistency of the then described test
It is good.
The present invention provides a kind of low voltage ride through of photovoltaic inverter property fitting system, may include:
Consistency module: passing through test according to the low voltage failure of setting and obtain electrical quantity, and verifies identical test not
The consistency for the electrical quantity that homogeneous is tested；
Fitting module: critical electrical amount is chosen according to the consistency of electrical quantity and carries out low voltage crossing feature fitting；
The electrical quantity include: the voltage steady-state value in front of low voltage failure and low voltage failure stable state section, low-voltage therefore
The preceding watt current steady-state value and reactive current steady-state value with low voltage failure stable state section of barrier, during low voltage failure restores
Electric current regeneration rate.
Feature fitting during feature fitting submodule and low-voltage are restored during the fitting module includes: low voltage failure
Submodule.
Feature fitting submodule includes: for by the idle electricity in low voltage failure stable state section during the low voltage failure
Stream steady-state value and the first fitting unit for carrying out curve fitting of voltage and for by the watt current in low voltage failure stable state section
The second fitting unit that steady-state value and voltage carry out curve fitting.
First fitting unit as the following formula carries out the reactive current steady-state value in low voltage failure stable state section and voltage
Curve matching:
Iq=min (Kq_LV(ULV-Uterm)+KIq0_flagIq0+Iq0_LV,Iqmax_LV)
In formula, IqFor the reactive current steady-state value in low voltage failure stable state section, Kq_LVFor reactive current support coefficient, ULV
For the voltage threshold for entering low voltage failure, UtermTo exchange side voltage, KIq0_flagMark coefficient, I are superimposed for reactive currentq0
For the reactive current steady-state value before low voltage failure, Iq0_LVFor the reactive current initial value of low voltage failure, Iqmax_LVFor low electricity
Press the maximum reactive current in failure stable state section.
Second fitting unit is as the following formula by the watt current steady-state value and voltage in low voltage failure stable state section
It carries out curve fitting:
In formula, IpFor the watt current steady-state value in low voltage failure stable state section, P0It is active before low voltage failure to enter
Power, UtermTo exchange side voltage, Imax_FRTFor the maximum current in low voltage failure stable state section, IqIt is steady for low voltage failure
The reactive current in state section, Ip0For the watt current steady-state value before low voltage failure, Kp1_FRTAnd KP2_FRT is equalFor watt current system
Number, Ip0_FRTFor the watt current initial value of low voltage failure, Ip_Flag is the watt current clipping in low voltage failure stable state section
Flag bit.
Feature fitting includes: to calculate electricity during feature fitting submodule carries out low-voltage recovery during the low-voltage is restored
Press to wear the average value of the electric current regeneration rate during more restoring.The consistency module includes for setting low voltage crossing test
Test submodule；
The test submodule setting low voltage crossing, which is tested, includes:
Drop to inverter ac side voltage respectively in the pre-set interval of voltage rating；
The pre-set interval of the voltage rating includes: 0~20%, 20%~30%, 50%~60% and 70%~90%.
The low voltage ride through of photovoltaic inverter property fitting system further includes that setting module is used to wear in setting low-voltage
Inverter initial launch operating condition is more set before test；
The operating condition includes high-power, mid power and small-power；
High-power operating condition refers to that inverter output power is the 70%~100% of rated power；
Mid power operating condition refers to that inverter output power is the 40%~60% of rated power；
Small-power operating condition refers to that inverter output power is the 10%~30% of rated power.
Embodiment
Before carrying out low voltage ride through of photovoltaic inverter property fitting, first build that inverter as shown in Figure 2 is low to wear test
Test macro mainly includes photovoltaic group string (square matrix)/analog DC source, inverter and grid disturbance generating system.
As shown in figure 3, being the basic procedure of inverter low voltage crossing property fitting:
Step 1: setting inverter initial launch operating condition by adjusting the maximum output of controllable direct current power supply, making respectively inverse
Become device to operate under three kinds of operating conditions of high-power, mid power and small-power, wherein high-power operating condition refers to inverter output power
It is the 70%~100% of rated power, mid power operating condition refers to that inverter output power is the 40%~60% of rated power,
Small-power operating condition refers to that inverter output power is the 10%~30% of rated power.
Step 2: setting low voltage failure passes through test, inverter ac side voltage is made to drop to the 0 of voltage rating respectively
~20%, 20%~30%, 50%~60% and 70%~90% section, identical test are at least repeated twice；
Step 3: watt current, reactive current steady-state value before calculating low voltage failure and during failure stable state, calculate event
Barrier restore during electric current regeneration rate, verification is the same as the not consistency of homogeneous test data in battery of tests；
Step 4: distinguishing operating condition, feature fitting packet of the overcurrent protection as boundary condition, during low voltage failure is considered
It includes: the active/relationship between reactive current steady-state value and voltage in low voltage failure stable state section is carried out curve fitting.
The fitting formula of reactive current is
Iq=min (Kq_LV(ULV-Uterm)+KIq0_flagIq0+Iq0_LV,Iqmax_LV) (1)
I in formulaqFor the reactive current during low voltage crossing, Kq_LVFor reactive current support coefficient, ULVTo enter low electricity
Press to wear the voltage threshold more controlled, UtermTo exchange side voltage, KIq0_flagMark coefficient, I are superimposed for reactive currentq0To enter
Reactive current before low voltage crossing control, Iq0_LVFor the reactive current initial value of low voltage crossing, Iqmax_LVIt is worn for low-voltage
The more maximum reactive current of control period.
The fitting formula of watt current is
I in formulapFor the watt current during low voltage crossing, P0To enter the active power before low voltage crossing control,
UtermTo exchange side voltage, Imax_FRTFor the maximum current for entering low voltage crossing control period, IqFor during low voltage crossing
Reactive current, Kp1_FRTFor watt current coefficient 1, Kp2_FRTFor watt current coefficient 2, IP0Before entering low voltage crossing control
Watt current, Ip0_FRTFor the watt current initial value of low voltage crossing, Ip_Flag is the watt current during low voltage crossing
Clipping flag bit.
Watt current steady-state value calculation formula before low voltage failure is
I in formulap0Indicate the watt current value in low voltage failure presteady state section, Kip0StartIndicate failure presteady state section
The data sequence number of start time, Kip0EndIndicate the data sequence number of failure presteady state section finish time.
Reactive current steady-state value calculation formula before low voltage failure is
I in formulaq0Indicate the reactive current value in low voltage failure presteady state section, Kiq0StartIndicate failure presteady state section
The data sequence number of start time, Kiq0EndIndicate the data sequence number of failure presteady state section finish time.
The watt current steady-state value calculation formula in low voltage failure stable state section is
I in formulapIndicate the watt current value in low voltage failure stable state section, KipStartWhen indicating that failure stable state section starts
The data sequence number at quarter, KipEndIndicate the data sequence number of failure stable state section finish time.
The reactive current steady-state value calculation formula in low voltage failure stable state section is
I in formulaqIndicate the watt current value in low voltage failure stable state section, KiqStartWhen indicating that failure stable state section starts
The data sequence number at quarter, KiqEndIndicate the data sequence number of failure stable state section finish time.
Low voltage failure restore during electric current regeneration rate calculation formula be
I in formulap_LV2For the watt current of fault recovery finish time, Ip_LV1For the active electricity of fault recovery start time
Stream, tp_LV2For fault recovery finish time, tp_LV1For fault recovery start time.
Feature fitting includes: that calculating current regeneration rate takes the average value repeatedly tested during low voltage failure restores.
The present invention is in order to verify the correctness of proposed approximating method, to the low voltage crossing of certain model photovoltaic DC-to-AC converter
Characteristic is fitted.According to Step 1: two, three development low voltage crossing tests, calculate the nothing during low voltage failure stable state
Function electric current and watt current steady-state value, and according to formula (1) and formula (2) by during failure stable state active/reactive current with
Relationship between voltage carries out curve fitting, and obtains the K in formula (1)q_LVTake 2, ULV0.9 is taken, KIq0_flagTake 0, Iq00 is taken,
Iq0_LVTake 0, Iqmax_LVTake 1.08；I in formula (2)p_Flag takes 2, Kp1_FRTTake 0, Kp2_FRTTake 0, Ip0_FRT0.16 is taken,
Imax_FRTTake 1.1；
To which the low voltage crossing property fitting formula for obtaining inverter is as follows:
Iq=min (2 × (0.9-Uterm),1.08)
Ip=0.16.
Measuring the electric current regeneration rate average value during low voltage failure restores is 1.25pu/s.
Inverter fitting formula and electric current regeneration rate parameter are substituted into electromechanical transient simulation model progress electromechanical transient to imitate
Very, simulation curve and measured curve have good consistency, as shown in Figure 4 and Figure 5.Pass through contrast simulation data and practical survey
The data of examination are it can be found that whether high-power operating condition or small-power operating condition, low voltage crossing characteristic proposed by the present invention are quasi-
Conjunction method can be good at the practical property for being fitted inverter, demonstrate the correctness and validity of proposed approximating method.
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 system 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 system, the instruction system 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.
Finally it should be noted that: the above examples are only used to illustrate the technical scheme of the present invention rather than to its protection scope
Limitation, although the application is described in detail referring to above-described embodiment, those of ordinary skill in the art should
Understand: those skilled in the art read the specific embodiment of application can still be carried out after the application various changes, modification or
Person's equivalent replacement, but these changes, modification or equivalent replacement, are applying within pending claims.
Claims (19)
1. a kind of low voltage ride through of photovoltaic inverter property fitting method characterized by comprising
Test is passed through according to the low voltage failure of setting and obtains electrical quantity, and verifies the identical test electricity that homogeneous is not tested
The consistency of tolerance；
Critical electrical amount, which is chosen, according to the consistency of electrical quantity carries out low voltage crossing feature fitting；
Before the electrical quantity includes: the voltage steady-state value in front of low voltage failure and low voltage failure stable state section, low voltage failure
Electric current during restoring with the watt current steady-state value and reactive current steady-state value in low voltage failure stable state section, low voltage failure
Regeneration rate.
2. low voltage ride through of photovoltaic inverter property fitting method as described in claim 1, which is characterized in that described according to electricity
The consistency of tolerance chooses critical electrical amount
It chooses the voltage steady-state value absolute value of the bias that homogeneous is not tested and is less than 0.05pu, watt current and reactive current stable state
It is worth the electric current regeneration rate absolute value of the bias during absolute value of the bias is less than 0.1pu, low voltage failure restores less than 0.2pu/s's
The electrical quantity of test is critical electrical amount.
3. low voltage ride through of photovoltaic inverter property fitting method as described in claim 1, which is characterized in that the low-voltage
Pass through feature fitting during feature fitting and low-voltage restore during feature fitting includes: low voltage failure.
4. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 3, which is characterized in that the low-voltage
Feature fitting includes: during failure
The reactive current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage；
The watt current steady-state value in low voltage failure stable state section is carried out curve fitting with voltage.
5. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 4, which is characterized in that as the following formula by institute
The reactive current steady-state value for stating low voltage failure stable state section carries out curve fitting with voltage:
Iq=min (Kq_LV(ULV-Uterm)+KIq0_flagIq0+Iq0_LV,Iqmax_LV)
In formula, IqFor the reactive current steady-state value in low voltage failure stable state section, Kq_LVFor reactive current support coefficient, ULVFor into
Enter the voltage threshold of low voltage failure, UtermTo exchange side voltage, KIq0_flagMark coefficient, I are superimposed for reactive currentq0It is low
Reactive current steady-state value before voltage failure, Iq0_LVFor the reactive current initial value of low voltage failure, Iqmax_LVFor low-voltage event
Hinder the maximum reactive current in stable state section.
6. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 5, which is characterized in that the low-voltage
Reactive current steady-state value I before failureq0Calculation formula it is as follows:
In formula, iq0Indicate the reactive current value in low voltage failure presteady state section, Kiq0StartIndicate low voltage failure presteady state area
Between start time data sequence number, Kiq0EndIndicate the data sequence number of low voltage failure presteady state section finish time.
7. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 5, which is characterized in that the low-voltage
The reactive current steady-state value I in failure stable state sectionqCalculation formula it is as follows:
I in formulaqIndicate the watt current value in low voltage failure stable state section, KiqStartIndicate that low voltage failure stable state section starts
The data sequence number at moment, KiqEndIndicate the data sequence number of low voltage failure stable state section finish time.
8. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 4, which is characterized in that as the following formula by institute
The watt current steady-state value for stating low voltage failure stable state section carries out curve fitting with voltage:
In formula, IpFor the watt current steady-state value in low voltage failure stable state section, P0To enter the wattful power before low voltage failure
Rate, UtermTo exchange side voltage, Imax_FRTFor the maximum current in low voltage failure stable state section, IqFor low voltage failure stable state
The reactive current in section, Ip0For the watt current steady-state value before low voltage failure, Kp1_FRTAnd KP2_FRT is equalFor watt current coefficient,
Ip0_FRTFor the watt current initial value of low voltage failure, Ip_Flag is the watt current clipping mark in low voltage failure stable state section
Will position.
9. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 8, which is characterized in that the low-voltage
Watt current steady-state value I before failurep0Calculation formula it is as follows:
In formula, ip0Indicate the watt current value in low voltage failure presteady state section, Kip0StartIndicate low voltage failure presteady state area
Between start time data sequence number, Kip0EndIndicate the data sequence number of low voltage failure presteady state section finish time.
10. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 8, which is characterized in that the low electricity
Press the watt current steady-state value I in failure stable state sectionpCalculation formula it is as follows:
I in formulapIndicate the watt current value in low voltage failure stable state section, KipStartIndicate that low voltage failure stable state section starts
The data sequence number at moment, KipEndIndicate the data sequence number of low voltage failure stable state section finish time.
11. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 3, which is characterized in that the low electricity
Feature fitting includes: the average value for calculating the electric current regeneration rate during voltage ride-through is restored during pressure is restored.
12. the low voltage ride through of photovoltaic inverter property fitting method as described in claim 1 or 11 is any, which is characterized in that
The calculation formula of electric current regeneration rate during the low voltage failure recovery is as follows:
In formula, dIp_LVElectric current regeneration rate during restoring for low voltage failure, Ip_LV2Restore finish time for low voltage failure
Watt current, Ip_LV1Restore the watt current of start time, t for low voltage failurep_LV2At the end of restoring for low voltage failure
It carves, tp_LV1Restore start time for low voltage failure.
13. low voltage ride through of photovoltaic inverter property fitting method as described in claim 1, which is characterized in that set low electricity
It further include setting inverter initial launch operating condition before pressing to wear more test；
The operating condition includes high-power, mid power and small-power；
High-power operating condition refers to that inverter output power is the 70%~100% of rated power；
Mid power operating condition refers to that inverter output power is the 40%~60% of rated power；
Small-power operating condition refers to that inverter output power is the 10%~30% of rated power.
14. low voltage ride through of photovoltaic inverter property fitting method as claimed in claim 13, which is characterized in that described sets
Determining low voltage crossing test includes:
Drop to inverter ac side voltage respectively in the pre-set interval of voltage rating；
The pre-set interval of the voltage rating includes: 0~20%, 20%~30%, 50%~60% and 70%~90%.
15. a kind of low voltage ride through of photovoltaic inverter property fitting system characterized by comprising
Consistency module: passing through test according to the low voltage failure of setting and obtain electrical quantity, and verifies identical test not homogeneous
Test the consistency of obtained electrical quantity；
Fitting module: critical electrical amount is chosen according to the consistency of electrical quantity and carries out low voltage crossing feature fitting；
Before the electrical quantity includes: the voltage steady-state value in front of low voltage failure and low voltage failure stable state section, low voltage failure
With the watt current steady-state value and reactive current steady-state value in low voltage failure stable state section, low voltage failure restore during electric current
Regeneration rate.
16. low voltage ride through of photovoltaic inverter property fitting system as claimed in claim 15, which is characterized in that the fitting
Feature fitting submodule during feature fitting submodule and low-voltage are restored during module includes: low voltage failure.
17. low voltage ride through of photovoltaic inverter property fitting system as claimed in claim 16, which is characterized in that the low electricity
During pressure failure feature fitting submodule include: for by the reactive current steady-state value in low voltage failure stable state section and voltage into
First fitting unit of row curve matching and for carrying out the watt current steady-state value in low voltage failure stable state section and voltage
Second fitting unit of curve matching.
18. low voltage ride through of photovoltaic inverter property fitting system as claimed in claim 17, which is characterized in that described first
Fitting unit as the following formula carries out curve fitting the reactive current steady-state value in low voltage failure stable state section with voltage:
Iq=min (Kq_LV(ULV-Uterm)+KIq0_flagIq0+Iq0_LV,Iqmax_LV)
In formula, IqFor the reactive current steady-state value in low voltage failure stable state section, Kq_LVFor reactive current support coefficient, ULVFor into
Enter the voltage threshold of low voltage failure, UtermTo exchange side voltage, KIq0_flagMark coefficient, I are superimposed for reactive currentq0It is low
Reactive current steady-state value before voltage failure, Iq0_LVFor the reactive current initial value of low voltage failure, Iqmax_LVFor low-voltage event
Hinder the maximum reactive current in stable state section.
19. low voltage ride through of photovoltaic inverter property fitting system as claimed in claim 17, which is characterized in that described second
Fitting unit as the following formula carries out curve fitting the watt current steady-state value in low voltage failure stable state section with voltage:
In formula, IpFor the watt current steady-state value in low voltage failure stable state section, P0To enter the wattful power before low voltage failure
Rate, UtermTo exchange side voltage, Imax_FRTFor the maximum current in low voltage failure stable state section, IqFor low voltage failure stable state
The reactive current in section, Ip0For the watt current steady-state value before low voltage failure, Kp1_FRTAnd KP2_FRT is equalFor watt current coefficient,
Ip0_FRTFor the watt current initial value of low voltage failure, Ip_Flag is the watt current clipping mark in low voltage failure stable state section
Will position.
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| CN110649647A (en) * | 2019-08-23 | 2020-01-03 | 广东电网有限责任公司 | Photovoltaic inverter low-voltage ride-through control based on reactive current boundary conditions under distribution network symmetric faults |
| CN112421651A (en) * | 2020-10-15 | 2021-02-26 | 中国电力科学研究院有限公司 | System power balancing method and device in low-voltage ride through process of photovoltaic inverter |
| CN112467781A (en) * | 2020-10-23 | 2021-03-09 | 中国电力科学研究院有限公司 | Active control method and system for photovoltaic power station |
| CN113872230A (en) * | 2021-09-24 | 2021-12-31 | 中国电力科学研究院有限公司 | New energy fault ride-through control parameter optimization method and device |
| CN114825486A (en) * | 2022-06-28 | 2022-07-29 | 中国电力科学研究院有限公司 | Reactive current support coefficient correction method and device for inverter |
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| CN110649647A (en) * | 2019-08-23 | 2020-01-03 | 广东电网有限责任公司 | Photovoltaic inverter low-voltage ride-through control based on reactive current boundary conditions under distribution network symmetric faults |
| CN112421651A (en) * | 2020-10-15 | 2021-02-26 | 中国电力科学研究院有限公司 | System power balancing method and device in low-voltage ride through process of photovoltaic inverter |
| CN112421651B (en) * | 2020-10-15 | 2022-10-04 | 中国电力科学研究院有限公司 | System power balancing method and device in low-voltage ride through process of photovoltaic inverter |
| CN112467781A (en) * | 2020-10-23 | 2021-03-09 | 中国电力科学研究院有限公司 | Active control method and system for photovoltaic power station |
| CN113872230A (en) * | 2021-09-24 | 2021-12-31 | 中国电力科学研究院有限公司 | New energy fault ride-through control parameter optimization method and device |
| CN113872230B (en) * | 2021-09-24 | 2023-10-20 | 中国电力科学研究院有限公司 | New energy fault ride-through control parameter optimization method and device |
| CN114825486A (en) * | 2022-06-28 | 2022-07-29 | 中国电力科学研究院有限公司 | Reactive current support coefficient correction method and device for inverter |
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