CN107240928A - A kind of power network lateral spacing power method of photovoltaic DC-to-AC converter - Google Patents
A kind of power network lateral spacing power method of photovoltaic DC-to-AC converter Download PDFInfo
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- CN107240928A CN107240928A CN201710300761.2A CN201710300761A CN107240928A CN 107240928 A CN107240928 A CN 107240928A CN 201710300761 A CN201710300761 A CN 201710300761A CN 107240928 A CN107240928 A CN 107240928A
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- power
- flag bit
- voltage
- power network
- photovoltaic
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- 238000000034 method Methods 0.000 title claims abstract description 26
- 238000011217 control strategy Methods 0.000 claims abstract description 6
- 230000005611 electricity Effects 0.000 claims description 5
- 230000010354 integration Effects 0.000 claims description 3
- 230000007613 environmental effect Effects 0.000 description 1
Classifications
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- H02J3/385—
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- H02J3/383—
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E10/00—Energy generation through renewable energy sources
- Y02E10/50—Photovoltaic [PV] energy
- Y02E10/56—Power conversion systems, e.g. maximum power point trackers
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- Supply And Distribution Of Alternating Current (AREA)
Abstract
The invention discloses a kind of power network lateral spacing power method of photovoltaic DC-to-AC converter, this method is realized based on state machine, and state machine has the over-pressed flag bit of power network and constant power output flag bit, and the control mode of DC/DC parts uses following control strategy：When power network overvoltage mark and invariable power mark are all 0, the MPPT programs of normal operation；When the over-pressed flag bit of power network is 1, when invariable power flag bit is 0, limit power program is performed, input power is reduced with disturbance input voltage method；When the over-pressed flag bit of power network is 1, when invariable power flag bit is 1, backward voltage disturbed value VrefIt is constant, use permanent input voltage control DC/DC to ensure that input power is certain.The present invention is avoided in power network overvoltage protection, and inverter starts repeatedly causes power attenuation and the impact to power network.
Description
Technical field
The present invention relates to photovoltaic DC-to-AC converter technical field, more specifically, more particularly to a kind of power network of photovoltaic DC-to-AC converter
Lateral spacing power method.
Background technology
From the point of view of total quantity consumed, China is an energy big country, but because environmental issue is increasingly serious, and traditional energy
Exhaustion, photovoltaic generation has obtained many concerns by its unique advantage.Current photovoltaic DC-to-AC converter is just towards high-power, low humorous
The direction of ripple is developed.
, will be with as long as line voltage is in working range but photovoltaic DC-to-AC converter is during grid-connected normal work
The Schema control prime DC/DC circuits of MPPT maximum power point tracking.If many high-power single-phase photovoltaic DC-to-AC converters are simultaneously grid-connected, and
And sunshine is sufficient, it is easy to cause power grid electric excessively sufficient and increase the harmonic wave rate of power network current, line voltage is raised, most
Damage or the three-phase imbalance of electrical appliance can be caused eventually.
General photovoltaic DC-to-AC converter control strategy is as shown in figure 1, during normal work, the DC/DC parts of inverter can be to photovoltaic
The output voltage V and output current I of plate are acquired, and according to method of perturbation or conductance increment method, photovoltaic panel are carried out maximum
Power points is tracked.And DC/AC parts are controlled by busbar voltage outer shroud and grid-connected current inner ring, accomplish to absorb input power
Meanwhile, realize line voltage and grid-connected current same-phase so as to grid-connected.
When controlling DC/ in MPPT modes before line voltage is increased to more than voltage on line side tolerance value, should now stopped
DC, due to PV voltages-power curve as shown in Fig. 2 can select to use reverse method of perturbation, to reduce input power as target,
Change input voltage reference value, until line voltage is returned to below tolerance value, but current control program complexity.
The content of the invention
, can be in grid side electricity it is an object of the invention to provide a kind of power network lateral spacing power method of photovoltaic DC-to-AC converter
When excessively sufficient, voltage on line side is higher, the power output of photovoltaic DC-to-AC converter is reduced, so that avoid in power network overvoltage protection, it is inverse
Change device starts repeatedly causes power attenuation and the impact to power network.
In order to achieve the above object, the technical solution adopted by the present invention is as follows：
A kind of power network lateral spacing power method of photovoltaic DC-to-AC converter, this method realizes that state machine has power network based on state machine
Over-pressed flag bit and constant power output flag bit, power network overvoltage flag bit is to be labeled as 1 when line voltage exceedes tolerance value, when
Line voltage is reset when returning to 220Vac；Constant power output flag bit is worked as under power network overpressure situation, when line voltage drops to appearance
When bearing value, invariable power flag bit is labeled as 1, and when line voltage is less than or equal to 220Vac, invariable power flag bit is reset；
The control mode of DC/DC parts uses following control strategy：
When power network overvoltage mark and invariable power mark are all 0, the MPPT programs of normal operation；
When the over-pressed flag bit of power network is 1, when invariable power flag bit is 0, limit power program is performed, with disturbance input voltage method
To reduce input power；
When the over-pressed flag bit of power network is 1, when invariable power flag bit is 1, backward voltage disturbed value VrefIt is constant, it is defeated using perseverance
Enter voltage control DC/DC to ensure that input power is certain.
Further, the state of the over-pressed flag bit of the power network and output constant power flag bit passes through state machine determining program
Perform, i.e.,：
S1, judge whether the over-pressed flag bit of power network is labeled as 1, S2 is then performed in this way, S3 is otherwise performed；
S2, continuation judge whether line voltage is less than or equal to tolerance value, and then constant power output flag bit is labeled as 1 in this way,
Otherwise constant power output flag bit is labeled as 0；In the case where constant power output flag bit is labeled as 1, continuation judges power network electricity
Whether pressure is less than or equal to 220V, and then the over-pressed flag bit of power network and constant power output flag bit mark and be in this way, otherwise power network mistake
Press flag bit and output constant power mark invariant position；
S3, continuation judge whether line voltage is more than 243V, and then the over-pressed flag bit of power network is labeled as 1 in this way, and invariable power is defeated
Go out flag bit labeled as 0, otherwise power network overvoltage indicates invariant position.
Further, the flow of the limit power program is specially：
S11, the input voltage U and electric current I for gathering photovoltaic panel；
S12, calculate now input power：P=U*I；
S13, calculate this time and last time input power difference power Δ P=P-Ppre；
S14, calculate this time and last time voltage voltage difference delta V=V-Vpre；
Whether the difference power Δ P in S15, judgment step S13 is more than 0, and step S16 is then performed in this way, step is otherwise performed
S17；
Whether the voltage difference delta V in S16, judgment step S14 is more than 0, and backward voltage disturbed value V is then calculated in this wayref=V-
DV, otherwise calculates backward voltage disturbed value Vref=V+dV；
Whether the voltage difference delta V in S17, judgment step S14 is more than 0, and backward voltage disturbed value V is then calculated in this wayref=V+
DV, otherwise calculates backward voltage disturbed value Vref=V-dV；
Wherein PpreIt is last time input power value, VpreIt is last time voltage, dV is voltage V integration.
Further, state machine determining program is performed once in timer interrupt program every 100uS.
Further, the tolerance value of voltage is 235V.
Compared with prior art, the advantage of the invention is that：The present invention is realized when voltage on line side exceedes maximum tolerance value
During 245Vac, actively reduce the power output of photovoltaic combining inverter to reduce power grid electric, to reduce grid side voltage.Avoid
When grid side voltage is higher than tolerance value, net side overvoltage protection makes photovoltaic combining inverter work-protect repeatedly switching, and leads
Cause power loss and power network side impact.
Brief description of the drawings
In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to embodiment or existing
There is the accompanying drawing used required in technology description to be briefly described, it should be apparent that, drawings in the following description are only this
Some embodiments of invention, for those of ordinary skill in the art, on the premise of not paying creative work, can be with
Other accompanying drawings are obtained according to these accompanying drawings.
Fig. 1 is existing photovoltaic DC-to-AC converter control strategy figure.
Fig. 2 is PV voltages-power curve of the prior art.
Fig. 3 is the policy map of the power network lateral spacing power method of photovoltaic DC-to-AC converter of the present invention.
Fig. 4 be photovoltaic DC-to-AC converter of the present invention power network lateral spacing power method in state machine determining program flow chart.
Fig. 5 be photovoltaic DC-to-AC converter of the present invention power network lateral spacing power method in drop power program flow chart.
Embodiment
The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings, so that advantages and features of the invention energy
It is easier to be readily appreciated by one skilled in the art, apparent is clearly defined so as to be made to protection scope of the present invention.
As shown in fig.3, idea of the invention is that, normal Chinese line voltage is 220Vac+7%-10%, and we hold
235Vac (220+7%) can be set to by bearing value.And 3% threshold value is set, i.e., when line voltage virtual value is more than 246Vac, limit
Volume program starts, and until the virtual value of line voltage maintains 235Vac or so, constant pressure (power) input control now may be selected.
If when detecting line voltage less than 220Vac (can inquire into) below, limit program is exited, again with MPPT mode controls
DC/DC processed.
Therefore, the present invention provides a kind of power network lateral spacing power method of photovoltaic DC-to-AC converter, this method is realized based on state machine,
State machine has the over-pressed flag bit of power network and constant power output flag bit, and power network overvoltage flag bit is when line voltage exceedes tolerance
1 is labeled as during value, is reset when line voltage returns to 220Vac；Constant power output flag bit is worked as under power network overpressure situation, when
When line voltage drops to tolerance value, invariable power flag bit is labeled as 1, and when line voltage is less than or equal to 220Vac, permanent work(
Rate flag bit is reset；
The control mode of DC/DC parts uses following control strategy：
When power network overvoltage mark and invariable power mark are all 0, the MPPT programs of normal operation；
When the over-pressed flag bit of power network is 1, when invariable power flag bit is 0, limit power program is performed, with disturbance input voltage method
To reduce input power；
When the over-pressed flag bit of power network is 1, when invariable power flag bit is 1, backward voltage disturbed value VrefIt is constant, it is defeated using perseverance
Enter voltage control DC/DC to ensure that input power is certain.
State machine determining program is performed once in timer interrupt program every 100uS.
As shown in fig.4, the state of the over-pressed flag bit of the power network and output constant power flag bit is judged by state machine
Program is performed, i.e.,：
S1, judge whether the over-pressed flag bit of power network is labeled as 1, S2 is then performed in this way, S3 is otherwise performed；
S2, continuation judge whether line voltage is less than or equal to tolerance value, and then constant power output flag bit is labeled as 1 in this way,
Otherwise constant power output flag bit is labeled as 0；In the case where constant power output flag bit is labeled as 1, continuation judges power network electricity
Whether pressure is less than or equal to 220V, and then the over-pressed flag bit of power network and constant power output flag bit mark and be in this way, otherwise power network mistake
Press flag bit and output constant power mark invariant position；
S3, continuation judge whether line voltage is more than 243V, and then the over-pressed flag bit of power network is labeled as 1 in this way, and invariable power is defeated
Go out flag bit labeled as 0, otherwise power network overvoltage indicates invariant position.
As shown in fig.5, the flow of the limit power program is specially：
S11, the input voltage U and electric current I for gathering photovoltaic panel；
S12, calculate now input power：P=U*I；
S13, calculate this time and last time input power difference power Δ P=P-Ppre；
S14, calculate this time and last time voltage voltage difference delta V=V-Vpre；
Whether the difference power Δ P in S15, judgment step S13 is more than 0, and step S16 is then performed in this way, step is otherwise performed
S17；
Whether the voltage difference delta V in S16, judgment step S14 is more than 0, and backward voltage disturbed value V is then calculated in this wayref=V-
DV, otherwise calculates backward voltage disturbed value Vref=V+dV；
Whether the voltage difference delta V in S17, judgment step S14 is more than 0, and backward voltage disturbed value V is then calculated in this wayref=V+
DV, otherwise calculates backward voltage disturbed value Vref=V-dV；
Wherein, PpreIt is last time input power value, VpreIt is last time voltage, dV is voltage V integration.
The present invention is realized when voltage on line side exceedes maximum tolerance value 245Vac, actively reduces photovoltaic combining inverter
Power output reduces power grid electric, reducing grid side voltage.Avoid when grid side voltage is higher than tolerance value, net side mistake
Pressure protection makes photovoltaic combining inverter work-protect repeatedly switching, and causes power loss and power network side impact.
Although being described in conjunction with the accompanying embodiments of the present invention, patent owner can be in appended claims
Within the scope of make various deformations or amendments, as long as no more than the present invention claim described by protection domain, all should
Within protection scope of the present invention.
Claims (5)
1. a kind of power network lateral spacing power method of photovoltaic DC-to-AC converter, it is characterised in that：This method is based on state machine realization, state machine
With the over-pressed flag bit of power network and constant power output flag bit, power network overvoltage flag bit is when line voltage exceedes tolerance value markers
1 is designated as, is reset when line voltage returns to 220Vac；Constant power output flag bit is worked as under power network overpressure situation, when power network electricity
When pressure drop is to tolerance value, invariable power flag bit is labeled as 1, and when line voltage is less than or equal to 220Vac, invariable power mark
Position is reset；
The control mode of DC/DC parts uses following control strategy：
When power network overvoltage mark and invariable power mark are all 0, the MPPT programs of normal operation；
When the over-pressed flag bit of power network is 1, when invariable power flag bit is 0, limit power program is performed, is dropped with disturbance input voltage method
Low input power；
When the over-pressed flag bit of power network is 1, when invariable power flag bit is 1, backward voltage disturbed value VrefIt is constant, using perseverance input electricity
Voltage-controlled DC/DC processed is to ensure that input power is certain.
2. the power network lateral spacing power method of photovoltaic DC-to-AC converter according to claim 1, it is characterised in that：The power network overvoltage
The state of flag bit and output constant power flag bit is performed by state machine determining program, i.e.,：
S1, judge whether the over-pressed flag bit of power network is labeled as 1, S2 is then performed in this way, S3 is otherwise performed；
S2, continuation judge whether line voltage is less than or equal to tolerance value, and then constant power output flag bit is labeled as 1 in this way, otherwise
Constant power output flag bit is labeled as 0；In the case where constant power output flag bit is labeled as 1, continuation judges that line voltage is
No to be less than or equal to 220V, then the over-pressed flag bit of power network and constant power output flag bit mark and are in this way, otherwise power network overvoltage mark
Will position and output constant power mark invariant position；
S3, continuation judge whether line voltage is more than 243V, and then the over-pressed flag bit of power network is labeled as 1, constant power output mark in this way
Will position is labeled as 0, otherwise power network overvoltage mark invariant position.
3. the power network lateral spacing power method of photovoltaic DC-to-AC converter according to claim 1, it is characterised in that：The limit power journey
The flow of sequence is specially：
S11, the input voltage U and electric current I for gathering photovoltaic panel；
S12, calculate now input power：P=U*I；
S13, calculate this time and last time input power difference power Δ P=P-Ppre；
S14, calculate this time and last time voltage voltage difference delta V=V-Vpre；
Whether the difference power Δ P in S15, judgment step S13 is more than 0, and step S16 is then performed in this way, step S17 is otherwise performed；
Whether the voltage difference delta V in S16, judgment step S14 is more than 0, and backward voltage disturbed value V is then calculated in this wayref=V-dV,
Otherwise backward voltage disturbed value V is calculatedref=V+dV；
Whether the voltage difference delta V in S17, judgment step S14 is more than 0, and backward voltage disturbed value V is then calculated in this wayref=V+dV,
Otherwise backward voltage disturbed value V is calculatedref=V-dV；
Wherein PpreIt is last time input power value, VpreIt is last time voltage, dV is voltage V integration.
4. the power network lateral spacing power method of photovoltaic DC-to-AC converter according to claim 2, it is characterised in that：State machine judges journey
Sequence is performed once in timer interrupt program every 100uS.
5. the power network lateral spacing power method of photovoltaic DC-to-AC converter according to claim 2, it is characterised in that：The tolerance value of voltage
For 235V.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201710300761.2A CN107240928B (en) | 2017-04-29 | 2017-04-29 | A kind of power grid lateral confinement power method of photovoltaic DC-to-AC converter |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201710300761.2A CN107240928B (en) | 2017-04-29 | 2017-04-29 | A kind of power grid lateral confinement power method of photovoltaic DC-to-AC converter |
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| CN107240928A true CN107240928A (en) | 2017-10-10 |
| CN107240928B CN107240928B (en) | 2019-11-19 |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109446584A (en) * | 2018-09-30 | 2019-03-08 | 桑顿新能源科技有限公司 | A kind of SOP evaluation method of battery management system to battery core Cross prevention |
| CN110445183A (en) * | 2019-09-11 | 2019-11-12 | 清华大学 | Photovoltaic converter autonomous mode method for handover control in micro-grid system |
| CN113806132A (en) * | 2021-09-22 | 2021-12-17 | 京东方科技集团股份有限公司 | Exception reset processing method and device |
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| CN104158204A (en) * | 2014-09-10 | 2014-11-19 | 安徽启光能源科技研究院有限公司 | Energy storage system control method for power converter |
| US20160134197A1 (en) * | 2014-11-07 | 2016-05-12 | Power Integrations, Inc. | Input overvoltage protection using current limit |
| CN106026170A (en) * | 2016-06-28 | 2016-10-12 | 天津科林电气有限公司 | Control method for adjusting photovoltaic grid-connected inverter input power according to power grid voltage |
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Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN104158204A (en) * | 2014-09-10 | 2014-11-19 | 安徽启光能源科技研究院有限公司 | Energy storage system control method for power converter |
| US20160134197A1 (en) * | 2014-11-07 | 2016-05-12 | Power Integrations, Inc. | Input overvoltage protection using current limit |
| CN106026170A (en) * | 2016-06-28 | 2016-10-12 | 天津科林电气有限公司 | Control method for adjusting photovoltaic grid-connected inverter input power according to power grid voltage |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109446584A (en) * | 2018-09-30 | 2019-03-08 | 桑顿新能源科技有限公司 | A kind of SOP evaluation method of battery management system to battery core Cross prevention |
| CN109446584B (en) * | 2018-09-30 | 2023-06-09 | 桑顿新能源科技(长沙)有限公司 | SOP estimation method for battery management system to over-discharge protection of battery cell |
| CN110445183A (en) * | 2019-09-11 | 2019-11-12 | 清华大学 | Photovoltaic converter autonomous mode method for handover control in micro-grid system |
| CN113806132A (en) * | 2021-09-22 | 2021-12-17 | 京东方科技集团股份有限公司 | Exception reset processing method and device |
| CN113806132B (en) * | 2021-09-22 | 2023-12-26 | 京东方科技集团股份有限公司 | Processing method and device for abnormal reset |
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