CN109193789A - A kind of inverter for photovoltaic power generation - Google Patents
A kind of inverter for photovoltaic power generation Download PDFInfo
- Publication number
- CN109193789A CN109193789A CN201811278462.4A CN201811278462A CN109193789A CN 109193789 A CN109193789 A CN 109193789A CN 201811278462 A CN201811278462 A CN 201811278462A CN 109193789 A CN109193789 A CN 109193789A
- Authority
- CN
- China
- Prior art keywords
- control portion
- inversion control
- inverter
- inverting part
- voltage
- 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.)
- Granted
Links
- 238000010248 power generation Methods 0.000 title claims abstract description 7
- 238000006243 chemical reaction Methods 0.000 claims abstract description 7
- 230000003750 conditioning effect Effects 0.000 claims description 40
- 238000005070 sampling Methods 0.000 claims description 18
- 238000000034 method Methods 0.000 claims description 16
- 230000008859 change Effects 0.000 claims description 15
- 230000005611 electricity Effects 0.000 claims description 14
- 238000001514 detection method Methods 0.000 claims description 7
- 230000000087 stabilizing effect Effects 0.000 claims description 7
- 230000008569 process Effects 0.000 claims description 6
- 238000012952 Resampling Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 19
- 101000821096 Homo sapiens Synapsin-2 Proteins 0.000 description 18
- 102100021994 Synapsin-2 Human genes 0.000 description 18
- 230000000694 effects Effects 0.000 description 5
- 230000005540 biological transmission Effects 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000007689 inspection Methods 0.000 description 3
- 238000002955 isolation Methods 0.000 description 3
- 238000011897 real-time detection Methods 0.000 description 3
- 239000003381 stabilizer Substances 0.000 description 3
- 230000003321 amplification Effects 0.000 description 2
- 239000003990 capacitor Substances 0.000 description 2
- 238000005516 engineering process Methods 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000005286 illumination Methods 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 238000012544 monitoring process Methods 0.000 description 2
- 238000003199 nucleic acid amplification method Methods 0.000 description 2
- 238000012545 processing Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 230000009466 transformation Effects 0.000 description 2
- 101000588130 Homo sapiens Microsomal triglyceride transfer protein large subunit Proteins 0.000 description 1
- 102100031545 Microsomal triglyceride transfer protein large subunit Human genes 0.000 description 1
- 230000006978 adaptation Effects 0.000 description 1
- 230000004888 barrier function Effects 0.000 description 1
- 238000012790 confirmation Methods 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 230000006837 decompression Effects 0.000 description 1
- 230000007812 deficiency Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 230000008030 elimination Effects 0.000 description 1
- 238000003379 elimination reaction Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 238000012423 maintenance Methods 0.000 description 1
- 230000006855 networking Effects 0.000 description 1
- 238000012827 research and development Methods 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000012546 transfer Methods 0.000 description 1
- 230000003245 working effect Effects 0.000 description 1
Classifications
-
- H02J3/383—
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J7/00—Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
- H02J7/34—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering
- H02J7/35—Parallel operation in networks using both storage and other dc sources, e.g. providing buffering with light sensitive cells
-
- H—ELECTRICITY
- H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
- H02J—CIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
- H02J9/00—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting
- H02J9/04—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source
- H02J9/06—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems
- H02J9/062—Circuit arrangements for emergency or stand-by power supply, e.g. for emergency lighting in which the distribution system is disconnected from the normal source and connected to a standby source with automatic change-over, e.g. UPS systems for AC powered loads
-
- 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
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B10/00—Integration of renewable energy sources in buildings
- Y02B10/70—Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Inverter Devices (AREA)
Abstract
The invention discloses a kind of inverters for photovoltaic power generation, and with ammeter terminal and face terminals, for ammeter terminal for being connected with two-way ammeter, which includes: inverting part, and the DC power conversion that photovoltaic module is generated is sine wave alternating current；First switch is connected between ammeter terminal and face terminals；Second switch is connected between inverting part and face terminals；Inversion control portion is connected to inverting part, first switch and the second switch；First synchronization unit, it is connected to ammeter terminal and inversion control portion, and be configured to transmit the first synchronization signal to inversion control portion when detecting that power grid is in power supply state, inversion control portion is additionally configured to according to whether the predetermined time is inscribed the first synchronization signal for being received in compliance with pre-provisioning request and controls inverting part and work in grid-connect mode or off-network mode after start-up operation.The electric energy that inverter of the invention can switch between multiple-working mode rationally and effectively photovoltaic module to be utilized to generate.
Description
Technical field
The present invention relates to photovoltaic power supply field, in particular to a kind of inverter for photovoltaic power generation.
Background technique
When photovoltaic module is passed through the getable power Transmission of conversion solar into power grid, it usually needs pass through inverter
The alternating current obtained by inversion is transported to by the direct current that photovoltaic module is generated after DC/DC transformation and DC/AC conversion
In power grid.
Fig. 1 is the structural schematic diagram of existing photovoltaic power supply system, and which illustrates between photovoltaic module, inverter and power grid
Connection type.As shown in Figure 1, the electric power that the owner of photovoltaic module needs first to generate photovoltaic module passes through gird-connected inverter
It is conveyed into power grid after being converted to alternating current, and the local load access power grid of electricity consumption will be needed to obtain power supply.It is grid-connected inverse
The electric power for becoming device feeding power grid is recorded by the first ammeter, and obtains remuneration according to sale of electricity price.Meanwhile local load from
The electric power that power grid obtains is recorded by the second ammeter, and the electric power provided according to power purchase price consumption power grid.
However, the power purchase expenditure electric far fewer than every degree based on the sale of electricity gained of every degree electricity due to the owner of photovoltaic module,
By according to existing photovoltaic power supply mode, the investment for withdrawing building photovoltaic power supply system at least needs 10 years or more.Although too
It is positive can solar panel service life up to 25 years, but in view of photovoltaic power supply system is also required to maintenance cost during running, thus
In the life cycle of solar panel, the getable return of the owner is seldom.And if to come by public subsidies
So that the photovoltaic system of existing powering mode is developed and popularizes, this is also very unpractiaca.
Another deficiency of gird-connected inverter in the prior art shown in Fig. 1 is, once grid power blackout, just can not
It works on, also cannot achieve multimachine joint power supply.
If according to micro-capacitance sensor architecture in the prior art (about this technology, can refer to application No. is
20101041039.7, the patent document of entitled " a kind of household multi-energy system and its control method ") it is existing to improve
Photovoltaic power supply system, complexity and be difficult to allow the photovoltaic system owner to receive the cost increaseing accordingly.
To sum up, the construction and mode for urgently improving photovoltaic power supply system at present are to promote this New Energy Industry of photovoltaic power supply
Development.
Summary of the invention
To solve the above-mentioned problems, the purpose of the present invention is to provide a kind of photovoltaic power supply systems with improved structure
System rationally and efficiently uses photovoltaic energy with realizing.
For this purpose, the present invention provides a kind of inverter for photovoltaic power generation, with ammeter terminal and face terminals,
The ammeter terminal with the two-way ammeter for being connected to power grid for being connected, and the face terminals are for connecting the inverter
Load, the inverter includes:
Inverting part, being connected to photovoltaic module and being configured to the DC power conversion for generating photovoltaic module is sine wave AC
Electricity；
First switch is connected between ammeter terminal and face terminals, and the first switch is normally closed switch；
Second switch is connected between inverting part and face terminals, and the second switch is open type switch；
Inversion control portion is connected to inverting part, first switch and the second switch, and is configured to control second switch inverse
Change portion connects when starting to work；
First synchronization unit is connected between the ammeter terminal and inversion control portion, and is configured to detecting electricity
The first synchronization signal is transmitted to inversion control portion when net is in power supply state,
Wherein, inversion control portion be further configured to the predetermined time after inverting part is started to work it is inscribed be received in compliance with it is predetermined
It is required that the first synchronization signal when control inverting part work in grid-connect mode, otherwise control first switch disconnect and control inverting part
Off-network mode is worked in, the grid-connect mode is the inverter and power grid joint powers to the load or inversion dress
It sets only to power grid power supply or the inverter simultaneously to the operating mode of power grid and load supplying, the off-network mode is
The operating mode that one or more described inverter only powers to the load,
Wherein, inversion control portion is further configured to be sampled according to the voltage and current of the input terminal from the inverting part
Busbar voltage BUSV and the sinusoidal magnitude voltage that is sampled of bus current BUSI, the voltage from the face terminals
SINV calculates or selects the modulation degree for being ready to use in inverting part prestored in real time, so that the inverter is in grid-connect mode
MPPT maximum power point tracking is executed based on the first modulation degree when work, is based on second when off-network mode works in separate unit inverter
Modulation degree executes pressure stabilizing and current limliting, and is executed together when more inverters are in off-network mode on-line working based on third modulation degree
Step, pressure stabilizing and current limliting.
Inverter through the invention, when meeting different predetermined conditions, it can be achieved that by power grid and photovoltaic power supply system
System is combined to local load supplying or from photovoltaic power supply system only to power grid power supply or from photovoltaic power supply system to power grid and originally
Ground load supplying or from photovoltaic power supply system only to the different powering modes of local load supplying, that is, inverter of the invention
It can switch between multiple-working mode rationally and effectively to utilize photovoltaic energy.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of existing photovoltaic power supply system.
Fig. 2 is the structural schematic diagram of the photovoltaic power supply system constructed using the inverter of the separate unit embodiment of the present invention.
Fig. 3 is the structural schematic diagram of the photovoltaic power supply system constructed using the inverter of more playscript with stage directions inventive embodiments.
Fig. 4 is the concrete structure schematic diagram of the photovoltaic power supply system in Fig. 2, and an implementation of inverter is shown
Each concrete composition component of example.
Fig. 5 is the configuration schematic diagram of the inverter control chip HT11560N as the inversion control portion in Fig. 3.
Fig. 6 is the overall workflow figure of the inverter of the embodiment of the present invention.
Fig. 7 is the exemplary circuit configuration figure of the inverting part of the embodiment of the present invention.
Fig. 8 A-8C is the exemplary circuit diagram of the signal conditioning unit of the embodiment of the present invention.
Fig. 9 is the exemplary circuit diagram of the third switch and accessory power supply of the embodiment of the present invention.
Figure 10 A and Figure 10 B are respectively the exemplary circuit diagram of the first switch K1 and second switch K2 of the embodiment of the present invention.
Figure 11 A and Figure 11 B are respectively the first synchronization unit of the embodiment of the present invention and the exemplary electrical of the second synchronization unit
Lu Tu.
Figure 12 is the exemplary circuit diagram in the inversion control portion of the embodiment of the present invention.
Figure 13 is short circuit, overcurrent and the thermal-shutdown circuit of the inverter of the embodiment of the present invention.
Specific embodiment
The inverter for photovoltaic power generation of the invention is described in detail with reference to the accompanying drawing.
Fig. 2 is the structural schematic diagram using the photovoltaic power supply system of separate unit inverter building of the invention.Fig. 3 is to utilize
The structural schematic diagram of the photovoltaic power supply system of the inverter building of more playscript with stage directions inventions.
As shown in Fig. 2, the photovoltaic power supply system allows to use by power grid 10 and the photovoltaic power supply system (including of the invention
Inverter 30 and photovoltaic module 50) combine the grid-connected powering mode powered to local load 40.When photovoltaic power supply system generates electricity
When, the preferential local load of supply is personal, is more than that the electricity consumption locally loaded or photovoltaic supply in the generated energy of photovoltaic power supply system
When electric system is left unused, the mode powered to power grid also can operate at.To cooperate the powering mode, can be filled in power grid 10 and inversion
It sets and connects two-way ammeter 20 between 30, to be used for the power supply volume of record power grid 10 and record the photovoltaic power supply system to power grid 10
The electricity of offer.As shown in figure 3, using inverter 30,130 of more playscripts with stage directions invention etc. and corresponding multiple photovoltaic modulies
50, the photovoltaic power supply system of the building on-line workings such as 150, the course of work under online mode will be described in detail hereinafter.
If the electricity consumption locally loaded is more than the generated energy of photovoltaic power supply system, by power grid and the photovoltaic power supply system
Combine to local load supplying.When grid power blackout, which is disconnected with power grid, with off-network powering mode to originally
Ground load supplying, the electrical hazard caused so as to avoid the island effect as caused by grid power blackout.Use inversion of the invention
The photovoltaic power supply system of device building, can rationally and effectively utilize photovoltaic energy, and the investment of photovoltaic system investor can be made to return
Receive cycle time at least half the time.
Fig. 4 is the concrete structure schematic diagram of the photovoltaic power supply system in Fig. 2, and an implementation of inverter is shown
Each concrete composition component of example.
As shown in figure 4, the inverter of the present embodiment have ammeter terminal and face terminals, ammeter terminal be used for it is two-way
Ammeter 20 is connected, and the other end of the two-way ammeter 20 is connected to power grid 10, which is the output end of inverter,
To be connected to load 40.The inverter include first switch 31 (in figure label be), second switch 32 (in figure label for
K2), inverting part 36, inversion control portion 35 and the first synchronization unit 33.
Wherein, inverting part 36 is connected to photovoltaic module 50, and the DC power conversion for generating photovoltaic module 50 is sine
It is exported by the output of second switch 32 to load 40 and/or by first switch 31 to power grid 10 after alternating current wave.First switch
31 are connected between ammeter terminal and face terminals, and first switch 31 can be normally closed switch.Second switch 32 is connected to inverse
Between change portion 36 and face terminals, second switch 32 can be open type switch.Inversion control portion 35 is connected to inverting part 36,
One switch 31 and second switch 32, inversion control portion 35 can control the connection when inverting part 36 is started to work of second switch 32,
So that the sine wave alternating current that inverting part 36 generates is sent to load 40 by second switch 32.First synchronization unit 33 is connected to
Between ammeter terminal and inversion control portion 35, for detected after inverter starts power grid 10 be normal power supply state when to
Transmit the first synchronization signal SYN1 in inversion control portion 35.
After inverter starting, if inversion control portion 35 start to work after in the predetermined time (such as 1 second, 5 seconds) from
First synchronization unit 33 receives the first synchronization signal SYN1 for meeting pre-provisioning request, then controls inverting part 36 and work in grid-connected mould
Formula.
Here the first synchronization signal SYN1 meet pre-provisioning request can be meet preset frequency require (alternatively referred to as grid-connected frequency
Rate requirement), meet predetermined voltage requirement (alternatively referred to as grid-connected voltage requirement) or meet preset frequency simultaneously and require and predetermined
Voltage requirement.Meet preset frequency to require to can be the frequency for the time-schedule float range for meeting rated frequency, meets predetermined voltage
It is required that can be the voltage for meeting the time-schedule float range of voltage rating.For example, being 220V for voltage rating, rated frequency is
The alternating current of 50Hz, frequency requirement can be 49.5Hz≤FSYN1≤ 50.5Hz, voltage require to can be 176V≤VSYN1≤264V。
If after inverter starting, not from the first synchronization unit in the predetermined time after inversion control portion 35 starts to work
When 33 the first synchronization signals (SYN1) for receiving the first synchronization signal SYN1 or receiving do not meet pre-provisioning request, then control inverse
Change portion 36 works in off-network mode.
In the present embodiment, above-mentioned grid-connect mode is the Working mould that inverting part 36 uses when power grid 10 is in power supply state
Formula, it may include inverter and power grid 10 combine the first mode powered to load 40, inverter only to the power supply of power grid 10
Second mode and inverter are simultaneously to the third mode of 40 power supply of power grid 10 and load.Off-network mode is that power grid 10 is in
Stop the operating mode that inverting part 36 uses when power supply state, it may include one or more inverter of the invention is only to load
The fourth mode of 40 power supplies.
In the present embodiment, inversion control portion 35 can be according to the bus of the voltage and current sample from 36 input end of inverting part
Voltage BUSV and bus current BUSI, and according to the sinusoidal magnitude voltage SINV of the voltage sample from face terminals, thus
It is counted in real time according to the sinusoidal magnitude voltage SINV of the busbar voltage BUSV of the sampling, the bus current BUSI of sampling and sampling
It calculates or the modulation degree for being ready to use in inverting part 36 that prestores of selection, so that the inverter is when grid-connect mode works based on the
One modulation degree executes MPPT maximum power point tracking, is executed when off-network mode works based on the second modulation degree in separate unit inverter steady
Pressure and current limliting, and synchronization, pressure stabilizing and limit are executed based on third modulation degree when more inverters are in off-network mode on-line working
Stream.
As described above, the inverter of the present embodiment can based on after inverter starts to the power supply state of power grid
Testing result and switch between multiple-working mode, and can calculate or select to current Working mould under each operating mode
Suitable modulation degree for formula, while can be realized the control of voltage, electric current or power, so as to rationally and effectively utilize light
The energy is lied prostrate, and can largely reduce the operating cost of photovoltaic power supply system.
In one embodiment of the invention, inverter further includes the second synchronization unit 34 as shown in Figure 4, connection
Between face terminals and inversion control portion 35.After inversion control portion 35 starts in inverter namely inversion control portion 35 opens
From the first synchronization unit 33 the first synchronization signal SYN1 is not received in the predetermined time after beginning work or from the first synchronization unit 33
In the case that the first synchronization signal SYN1 received does not meet scheduled grid-connected frequency requirement, inversion control portion 35 is to be controlled inverse
When change portion 36 works in off-network mode, and controls and disconnect first switch 31 and be closed second switch 32.Second synchronization unit 34
(detect whether to be more with the presence or absence of the sine wave alternating current by another same inverter output at detection face terminals
The case where inverter online power supply), if detecting that there are the sine wave alternating currents at face terminals, to inversion control portion
35 the second synchronization signal SYN2 of transmission.
Correspondingly, inversion control portion 35, which will detect whether to receive when inverting part 36 to be controlled works in off-network mode, comes
From the second synchronization signal SYN2 of the second synchronization unit 34, before receiving and meeting the second synchronization signal SYN2 of pre-provisioning request
Inversion control portion 35 works in single machine off-network mode or host off-network mode with scheduled modulation degree control inverting part 36, is receiving
To inversion control portion 35 after the second synchronization signal SYN2 for meeting pre-provisioning request according to related to another inverter
Modulation degree work in slave off-network mode to control inverting part 36.Here the second synchronization signal SYN1 meet pre-provisioning request can be with
It is to meet scheduled frequency requirement, meets preset frequency and require to can be the frequency for the time-schedule float range for meeting rated frequency,
For example, scheduled frequency requirement can be 49.5Hz≤F when rated frequency is 50HzSYN2≤50.5Hz。
In the present embodiment, off-network mode is further divided into single machine off-network mode, host off-network mode and slave off-network
Mode.In single machine off-network mode, powered using the inverter of separate unit the present embodiment to load 40；In host off-network mode
In, guide other one or more same inverters to load 40 as host by this inverter of the present embodiment
Online power supply；In slave off-network mode, this inverter of the present embodiment is as slave above-mentioned another same inverse
Become under the guidance of device and is enabled adaptation to 40 online power supplies of load with constructing online power supply system of certain scale
The use demand of different loads.
In embodiments of the present invention, during inverting part 36 works in slave off-network mode, if exported in inverting part 36
After the current period of sine wave in the predetermined time, inversion control portion 35 can't detect the second synchronization signal SYN2, then conduct
The inversion control portion 35 that can't detect the inverter of the second synchronization signal SYN2 in each inverter of slave first will stop
Detect the second synchronization signal SYN2, the inversion control portion 35 first continue according to make on the basis of current modulation degree inverting part 36 export
Sine wave, and so that inverting part 36 is worked in host off-network mode since next period.
In another embodiment of the invention, inverter further includes signal conditioning unit 37, be connected to face terminals,
Inverting part 36 and inversion control portion 35.During inverting part 36 works in single machine off-network mode or host off-network mode, signal tune
Reason unit 37 passes after improving the sinusoidal magnitude voltage SINV at the bus current BUSI and face terminals of inverting part 36
It is sent to inversion control portion 35.
Bus current BUSI and sinusoidal magnitude voltage of 35 pairs of the inversion control portion after the conditioning of signal conditioning unit 37
SINV each cycle is at least once sampled, and sampled value is compared with setting value.When inversion control portion 35 determines to sample
Bus current BUSI be not more than the first setting value when, inversion control portion 35 adjust inverting part 36 modulation degree, until inversion control
35 last samples of portion processed to sinusoidal magnitude voltage SINV meet the reference voltage range of setting.And when inversion control portion 35 is sentenced
Surely the bus current BUSI sampled is greater than the first setting value and when less than the second setting value, then 35 Cycle by Cycle of inversion control portion reduces
The modulation degree of inverting part 36, the bus current BUSI that 35 last samples arrive until inversion control portion are not more than the first setting value.
Above-mentioned each cycle at least carries out once sampling each of the sine wave for referring to and exporting in inverting part 36 in the present embodiment
One or many samplings are carried out in period.
In the present embodiment, if the recommended current of photovoltaic module 50 be I1, short circuit current I2, then it is above-mentioned to be used for
The first setting value compared with bus current BUSI is chosen as 1.01I1~1.05I1, the second setting value be chosen as 0.95I2~
1.0I2。
In addition, then determine that inverter breaks down when the bus current BUSI sampled is greater than the second setting value, it can
So that inverting part 36 stops working immediately and disconnects second switch 32 to prevent electrical hazard.
In the present embodiment, the sine wave that inverting part 36 exports is monitored by signal conditioning unit 37 and inversion control portion 35
Alternating current, and adjust the modulation degree of inverting part 36 according to monitoring data by inversion control portion 35 or close inverting part 36, thus
Achieve the purpose that pressure stabilizing or safety during inverting part 36 works in single machine off-network mode.
In another embodiment of the present invention, it is connected to the upper of the face terminals, inverting part 36 and inversion control portion 35
It states signal conditioning unit 37 to be configurable for during inverting part 36 works in slave off-network mode, exist at face terminals
The sine wave alternating current by above-mentioned another same inverter output sinusoidal magnitude voltage SINV and inverting part 36
Bus current BUSI and busbar voltage BUSV improved after be transmitted to inversion control portion 35, inversion control portion 35 is then to through believing
Sinusoidal magnitude voltage SINV, bus current BUSI and busbar voltage BUSV after number conditioning unit 37 improves are sampled, and
It is determined according to the ratio between the sinusoidal magnitude voltage SINV of present sample and busbar voltage BUSV for inverting part 36
The modulation degree in next period, and inverting part 36 is started according to the second synchronization signal SYN2 that the second synchronization unit 34 generates and is started
Export sine wave.
In the present embodiment, this reality is determined according to the running parameter of the online another same inverter to power to the load
The running parameter of this in example inverter is applied, so that this in the present embodiment inverter is as slave in another inversion
It is run under the guidance of device, realizes more online synchronize of inverter and power to the load.
In the above-described embodiments, determine that the bus current BUSI of sampling was not more than for the first setting value phase in inversion control portion 35
Between, 35 each cycle of inversion control portion repeats the process of the modulation degree in the above-mentioned determination inverting part (36) next period；Work as inversion
Control unit 35 determines that the bus current BUSI of sampling is greater than the first setting value and when less than the second setting value, inversion control portion 35 by
Period reduces the modulation degree for being used for inverting part 36, and the bus current BUSI that 35 last samples arrive until inversion control portion is no more than the
One setting value.
In the present embodiment, if the recommended current of photovoltaic module 50 be I1, short circuit current I2, then it is above-mentioned to be used for
The first setting value compared with bus current BUSI is chosen as 0.95I2~1.0I2, the second setting value be chosen as 1.01I1~
1.05I1.In addition, then determining that inverter is likely to occur event when the bus current BUSI sampled is greater than the second setting value
Barrier, may make inverting part 36 to stop working immediately and disconnects second switch 32 to prevent electrical hazard.
In the present embodiment, the sine wave that inverting part 36 exports is monitored by signal conditioning unit 37 and inversion control portion 35
Alternating current, and adjust the modulation degree of inverting part 36 according to monitoring data by inversion control portion 35 or close inverting part 36, thus
Achieve the purpose that pressure stabilizing or safety during inverting part 36 works in slave off-network mode.
In another embodiment, situation about worked under grid-connect mode to inverter devises modulation degree
Selected scheme.
In this embodiment, the above-mentioned signal condition being connected between face terminals, inverting part 36 and inversion control portion 35
Unit 37 is to the sinusoidal magnitude voltage SINV of the sine wave alternating current of power grid existing at face terminals and the mother of inverting part 36
Line voltage BUSV is transmitted to inversion control portion 35 after being improved.
Inversion control portion 35 is in for receiving the first synchronization signal SYN1 of the first synchronization unit 33 sending and receiving
When one synchronization signal SYN1 meets scheduled frequency range (that is, when inverting part to be controlled 36 works in grid-connect mode), inversion control
Portion 35 processed can to through signal conditioning unit 37 conditioning after sinusoidal magnitude voltage SINV and busbar voltage BUSV sample,
When sinusoidal magnitude voltage SINV meets scheduled voltage range, according to the sinusoidal magnitude voltage SINV and bus of present sample
Ratio between voltage BUSV determines the modulation degree in next period for inverting part 36, and according to the modulation degree of the determination and
First synchronization signal SYN1 works in grid-connect mode to control inverting part 36.Here, selected modulation degree, which needs to be less than, is equal to
1.02 could start the start-up operation of inverter 36.
In the present embodiment, the parameter of power grid alternating current can be used to determine the running parameter of inverting part 36, so as to simultaneously
Alternating current is exported to load with making inverting part 36 and synchronized during net mode.
In still another embodiment of the process, the MPPT maximum power point tracking scheme of inverter of the invention is devised.
In the present embodiment, during inverting part 36 works in grid-connect mode, signal conditioning unit 37 is to inverting part 36
Sinusoidal magnitude voltage SINV at bus current BUSI, busbar voltage BUSV and face terminals is transmitted to inversion after being improved
Control unit 35.
Bus current BUSI, busbar voltage BUSV and sine of 35 pairs of the inversion control portion after the conditioning of signal conditioning unit 37
Wave amplitude threshold voltage SINV is sampled, and sampled signal is compared with setting value.As the bus current BUSI for determining sampling
When greater than the second setting value, inversion control portion 35 immediately turns off the output of inverting part 36 and disconnects second switch 32.
When the bus current BUSI for determining sampling is not more than the second setting value (if solar cell module photovoltaic module 50
Recommended current be I1, then the second setting value is chosen as 1.01I1~1.05I1) when, and sinusoidal magnitude voltage and female
When ratio SINV/BUSV (i.e. modulation degree)≤such as 1.02 between line voltage, inversion control portion 35 calculates current bus current
The product P of BUSI and busbar voltage BUSVn=BUSIn*BUSVn, that is, the operating power of inverting part 36.
Then inversion control portion 35 will be used for the modulation degree of inverting part 36 towards the positive direction or negative sense changes Δ M, after the change
The busbar voltage BUSI and bus current BUSV of resampling are obtained under modulation degree, then calculate the busbar voltage BUSV of resampling
With the product P of bus current BUSIn+1=BUSIn+1*BUSVn+1.Here the Δ M changed every time can be such as 0.001 to 0.01
Between value.
If determining P after calculatingn+1>Pn, then inversion control portion 35 continues in the same direction to change current modulation degree again
Become Δ M, until calculating the P obtainedn+s≥Pn+s+1Until, no longer change modulation degree；And if determining P after calculatingn+1<Pn, then inverse
Become control unit 35 towards it is above-mentioned positively and negatively in another direction current modulation degree is changed into Δ M again, until calculate obtain
Pn+s≥Pn+s+1, until, no longer change modulation degree.Wherein, s is to calculate operating power P from first timenModulation degree is changed later
Become the number of Δ M.
As the P for determining that calculating obtainsn+s≥Pn+s+1When, inversion control portion 35 can continue using corresponding to current maximum work
Rate point Pn+sModulation degree and the first synchronization signal SYN1 control the output of inverting part 36.After a set time period, inversion
Control unit 35 can repeat above-mentioned determining Pn+sAnd the process of inverting part 36 is controlled, the inverter that the present embodiment can be realized is defeated
The MPPT maximum power point tracking (MPPT) of alternating current out.
Above-described embodiment can dynamically realize MPPT maximum power point tracking through the invention, in the set time period using choosing
Fixed modulation degree carrys out work, and repeats above-mentioned MPPT maximum power point tracking process after a set time, selectes again preferable
Modulation degree carrys out work.Above-mentioned setting time can be determined according to the working condition of photovoltaic module, such as same day illumination change
When smaller, setting time can be determined as to a longer time, such as 1 hour or 0.75 hour, same day illumination change is larger
When, setting time can be determined as to a shorter time, such as 10 minutes or 5 minutes etc..
In another embodiment of realization MPPT maximum power point tracking of the invention, can with following real-time detection method come
Instead of the method for above-mentioned set period of time.
Specifically, in inverting part 36 to correspond to the maximum power point P being recently determinedn+sModulation degree carry out sine wave
During output, inversion control portion 35 can each period of the sinewave output same corresponding instance sample and store bus
Electric current BUSI, busbar voltage BUSV and sinusoidal magnitude voltage SINV, and calculate separately to sample in this way in two adjacent periods and obtain
Two bus current BUSI between absolute difference A1, two busbar voltage BUSV between absolute difference A2 and two just
Absolute difference A3 between string wave amplitude threshold voltage SINV.
Inversion control portion 35 sinewave output waveform each period to above three absolute difference A1-A3 and setting value
It is compared, when any one value in A1-A3 is not less than setting value within the continuous predetermined period, inversion control portion 35 is just
Above-mentioned determining maximum power point P is executed againn+sProcess, and with the first synchronization signal SYN1 and with determining maximum work again
Rate point Pn+sCorresponding modulation degree controls the output of inverting part 36.
The MPPT maximum power point tracking of optimal effectiveness may be implemented in real-time detection method through this embodiment, sufficiently improves
Energy conversion efficiency.
In addition, in contrast, the duty that the gird-connected inverter of the prior art as shown in Figure 1 passes through adjusting DC/DC link
The maximum point tracking (MTTP) that DC/AC output power is realized than D, due to two links of DC/DC and DC/AC, tracking
Efficiency and reliability is lower.And the inverter in the embodiment of the present invention only one DC/AC link, pass through and adjusts inverting part
Modulation degree (or being busbar voltage BUSV utilization rate, i.e. the ratio between sinusoidal magnitude amplitude voltage SINV and busbar voltage BUSV) is come
Realize MPPT maximum power point tracking, fewer than a prior art link, tracking efficiency and reliability is higher.
In one more embodiment of the present invention, during inverting part 36 works in off-network mode, when the first synchronization unit 33
The first synchronization signal SYN1 can be transmitted to inversion control portion 35 again when power system restoration power supply by detecting, inversion control portion 35 then exists
After the first synchronization signal SYN1 for receiving the transmission of the first synchronization unit 33, it can determine that power grid has restored electricity, then control is closed
It closes first switch 31 and controls inverting part 36 and be switched to and work in grid-connect mode.The selected mode that grid-connect mode lowers system can adopt
With the method in such as the above embodiment of the present invention.
In the present embodiment, inverting part 36 can be when condition meets from off-network pattern switching to grid-connect mode, thus originally
The inverter of embodiment can correspond to different conditions and be switched to corresponding operating mode.
In an alternative embodiment of the invention, during inverting part 36 works in grid-connect mode, the first synchronization unit is being detected
When stopping powering to power grid, inversion control portion 35 once no longer receives the first synchronization signal of the first synchronization unit 33 transmission
SYN1, is just immediately controlled to disconnect first switch 31 and control inverting part 36 and be switched to and works in off-network mode.
Within the predetermined time being switched to after off-network mode, inverting part 36 still (can be kept according to original running parameter
Frequency, phase and modulation degree are constant) export sine wave alternating current, while inversion control portion 35 is according to whether detect from
Second synchronization signal SYN2 of two synchronization units 34 works in single machine off-network mode, host off-network mode also to control inverting part 36
It is slave off-network mode.Wherein, single machine off-network mode or host off-network mould are worked in when inversion control portion 35 controls inverting part 36
When formula, inverting part 36 can continue to export sine wave alternating current according to original running parameter.In addition, joining in more inverters
During machine works, when host therein is stopped working due to failure, can no longer it be received by detecting at first from the master
The slave of second synchronization signal SYN2 of machine takes on new host, so that other slaves be guided to continue work of networking.
In the present embodiment, precautionary measures are taken to the island effect for stopping may cause due to power supply because of power grid, that is, one
Denier detects that power grid stops power supply during grid-connect mode works, then the generation of island effect in order to prevent, disconnects inversion immediately
Being electrically connected between device and power grid, and inverting part 36 is switched to and works in off-network mode, so as to avoid by island effect
The generation of caused electrical hazard.
In one embodiment of the invention, inverter further includes third switch 38 as shown in Figure 4, one end connection
Between photovoltaic module 50 and inverting part 36, the other end is connected to the accessory power supply 39 of inverter 30.Third switch 38 can be with
It is manual switch, in order to which user can easily disconnect the power supply to the accessory power supply 39 of inverter 30 manually, thus
So that inverter 30 stops working.The inverter of the present embodiment can be set to be in closed state when third switch 38,
And 50 output voltage of photovoltaic module is greater thanWhen, accessory power supply 39 is just started to work, and then inverter is in accessory power supply
It starts to work under 39 power supply.Here K is proportionality coefficient, and K can be the value between 0.75 to 1.0, and A is that quasi- grid-connected voltage has
Valid value can determine according to the difference of territory of use, for example, can for 220V (corresponding 50Hz), 115V (corresponding 60Hz) or
230V (corresponding 50Hz) etc..
In other alternative embodiments of the invention, during inverting part 36 works in grid-connect mode or off-network mode, when
When inversion control portion 35 detects that the bus current BUSI of inverting part 36 is substantially equal to no-load current, inverting part 36 can control to stop
Work, and start inverting part 36 at predetermined time intervals and detect bus current BUSI, until detecting that bus current BUSI is big
When no-load current, control inverting part 36 is restored to power to load 40.
In this embodiment, the unloaded operation of inverting part 36 when being not connected with having load at face terminals is avoided, thus
Electric power has been saved, the service life of inverter is extended.
Task Parameter Interpretation
The running parameter of the photovoltaic module 50 of inverter of the invention is illustrated below.When inversion of the invention fills
Set it is quasi- when working in grid-connect mode, if the virtual value of network voltage is A, it is required that the open-circuit voltage of photovoltaic module 50 is less than
2A, and optimum operating voltage is greater thanFor example, then the open circuit of photovoltaic module 50 is electric when the virtual value of network voltage is 220V
Pressure is less than 440V, and its optimum operating voltage is greater than 311V.Therefore, if the solar panel of composition photovoltaic module 50 is opened
Road voltage is 22V, optimum operating voltage 17.5V, then such 19 pieces of solar panels is needed to form photovoltaic module 50,
That is, open-circuit voltage is 418V, optimum operating voltage 332.5V.
Full bridge inverter can be used in inverting part 36 in inverter of the invention, and DSP can be used in inversion control portion 35
(Digital Signal Processing, Digital Signal Processing), MCU (Microcontroller Unit, micro-control unit)
Or the programmable chips such as SOC (System on Chip, system level chip) are realized, deep core Thailand industry science and technology (north can also be selected
Capital) Co., Ltd (Corporation web site www.harmotech.cn) research and development model HT11560N inversion control chip come it is real
It is existing.
Fig. 5 is the configuration schematic diagram of the HT11560N chip.As shown, the pin 1 of the chip is the end reference voltage VCC
Son, pin 14 are grounded；Pin 2 receives the first synchronization signal SYN1 from the first synchronization unit 33, and pin 4, which receives, comes from second
Second synchronization signal SYN2 of synchronization unit 34；Pin 7-10 is respectively transmitted for controlling four switching devices in inverting part 36
Cut-off/close signal S1-S4；Pin 5 and 6 is respectively transmitted the letter of the cut-off/close for first switch and the second switch
Number；Pin 3,12-13 receive bus current sampled signal BUSI, sine voltage from signal conditioning unit 37 respectively and sample
Signal SINV and busbar voltage sampled signal BUSV；And pin 11 is used for Fault Control, controls and closes when confirmation is broken down
Close inverting part 36.
Be broadly divided into two schemes when current existing inversion chip application unipolarity modulation, i.e., the modulation of mixing unipolarity with
The modulation of low-and high-frequency arm unipolarity, and all there are four non-uniform phenomenons of MOS switch dissipation in both unipolarity inversion transformation techniques.
And HT11560N chip exchanges Harmonics elimination unipolarity number modulation technique using low-and high-frequency arm, can substantially eliminate above-mentioned open
Close the situation of device heating unevenness.Using same experiment porch, the same load of band and in the condition of identical time that works
Under, the result for being compared test to above-mentioned three kinds of chips is four derailing switches when modulating chip using low-and high-frequency arm unipolarity
The temperature difference of part is 20 DEG C, and the temperature difference of four switching devices is 10 DEG C when using mixing unipolarity modulation chip, and uses
The temperature difference of four switching devices is 0 DEG C when HT11560N chip, it is seen that compared with existing modulation chip, HT11560N chip tool
There is good working performance.
The main working parameters of HT11560N are as follows: fundamental frequency F=50Hz or 60Hz (can automatic identification)；Modulation degree M
=0.65~0.98；Built-in dead zone: 2.0ms；Carrier frequency Fc=12.5KHz (corresponding fundamental frequency 50Hz) or 12.6KHz are (right
Answer fundamental frequency 60Hz)；Harmonic carcellation number: 2~250 (corresponding fundamental frequency 50Hz) or 2~210 (corresponding fundamental frequencies
60Hz)；Traceable frequency range: 48.5~51.5Hz or 58.2~61.8Hz；LC filtering requirements: LC product be 4.7mH μ F~
10mHμF；Average frequency of switching: 6.25KHz (corresponding fundamental frequency 50Hz) or 6.3KHz (corresponding fundamental frequency 60Hz)；Work
Temperature: -40 DEG C~+85 DEG C.
Fig. 6 is the overall workflow figure of inverter of the invention, and Fig. 6 is described in detail below with reference to Fig. 4.
As shown in fig. 6, after judgement meets power-up conditions, so that inverter electrifying startup.Before being worked normally after starting
It needs to carry out a series of judgements:
The output terminal for first determining whether the photovoltaic module 50 for being connected to the input end of inverter 30 is just to connect or instead
It connects, if reversed, i.e. the positive output terminals of photovoltaic module 50 are connected to the negative input terminal of inverter 30, then make
Inverter hard stop, to be checked, if it is just connecing, i.e. the positive output terminals of photovoltaic module 50 are correctly connected
To the positive input terminal of inverter 30, then enter next judgement；
Secondly judge whether the third switch K3 being connected between accessory power supply 39 and inverting part 36 is closed, if K3 is disconnected
It opens, then inverter is shut down, and to be checked, if K3 has been closed, enters next judgement；
Next judge whether the input voltage of inverter 30 has the case where over-voltage overvoltage/undervoltage, if so, then shutting down inspection
It looks into, judges in next step if it is not, entering；
The output end of inverter 30 is judged later with the presence or absence of the situation of short circuit, if there is then shutdown inspection, if do not had
There are short-circuit conditions, then enters and judge in next step；
Below the utility grid 10 that is connect with inverter 30 (passing through two-way ammeter 20) of detection whether there is alternating current (according to
First synchronization signal SYN1), if there is alternating current, then detect whether grid-connected voltage, frequency meet relevant regulations, if meeting rule
Fixed, then inverter 30 works in the grid-connect mode combined with utility grid 10 and powered to load 40；And if detection is not present
Alternating current, or there are alternating current but grid-connected voltage and frequency it is against regulation, then detect whether that there are other similar inverters
(according to the second synchronization signal SYN2), it is if there is other similar inverters (there is the second synchronization signal SYN2), then inverse
Become device 30 and work in slave off-network mode, if there is no other similar inverters, then inverter 30 works in master
Machine off-network mode.
Wherein, during inverter 30 works in slave off-network mode, slave be more than one in the case where and host
When shutting down for some reason, first slave that can't detect the second synchronization signal SYN2 transfers to work in host off-network mould in these slaves
Formula.
In addition, also the presence of constantly detection alternating current (detects whether to deposit during inverter 30 works in grid-connect mode
In the first synchronization signal SYN1), once alternating current is not present, just according to whether there is other similar inverters to determine in work
It is to enter slave off-network mode or host off-network mode.
Equally, during inverter 30 works in host off-network mode or slave off-network mode, city is also constantly detected
Electricity presence (detecting whether that there are the first synchronization signal SYN1), once detect the presence of alternating current, then according to grid-connected voltage with
Whether frequency meets regulation and determines whether to be changed into grid-connect mode.
No matter moreover, inverter 30 work under grid-connect mode or off-network mode, equal real-time detection inverter 30
Whether occur overcurrent, excess temperature, short circuit, third switch K3 disconnection, over-voltage, it is under-voltage situations such as, once occur in which at least one feelings
Condition, then hard stop is to be checked, re-powers starting again after inspection meets power-up conditions.
Below with regard to the group of each circuit unit in the exemplary circuit configuration of inverter of the invention in Fig. 7-13
At and parameter selection be illustrated respectively.As an example, here with output voltage 220V/ output frequency 50Hz (or 60Hz)/defeated
Power is illustrated lower than the case where 3KW out.
Fig. 7 is the exemplary circuit configuration figure of inverting part of the invention.
36 main part of inverting part realizes full-bridge invertings by four NMOS tube Q1-Q4, and (model can be with for the 5th NMOS tube
Q1-Q4 is identical) Q5 realizes reverse connecting protection and current/voltage-converted (circuit part in Fig. 7 in dotted line frame).Common mode inductance LL1
Realize that input filter, common mode inductance LL2 realize output filtering.The inductance value of LL1 and LL2 can be 0.5-1.0mH.
Differential mode inductance L1 realizes input filter, and resonance is realized together with CBB2, CBB3, and have following formula (1) and (2):
Wherein, fcFor the carrier frequency in inversion control portion 35, the i.e. frequency of carrier signal of HT1156GP: 13.5KHz.Choosing
When CBB2=CBB3=100 μ F, 139 μ H of L1 ≈.
In the parameter selection of output inductor L2, L3 and capacitor CBB8, CBB9, when select HT1156GP as inversion
When controlling chip, THD≤3% of output sine wave is such as required, then output inductor and capacitor need to meet following formula (3):
Here, V is output sinusoidal magnitude, can be 220V；I is output sine-wave current, in the present embodiment, I≤
3KW/220V；Modulation degree when M is inversion, the value range of M can be 0.64~0.99, in the present embodiment desirable 0.75 M；
F is output sine wave freuqency, can be 50Hz or 60Hz；fcFor cutoff frequency, when inversion control chip is HT1156GP, fc
Actually carrier frequency.
In embodiments of the present invention, L2=L3=0.5~1.0mH, CBB8=CBB9=2.2 μ F may be selected.
Fig. 8 A-8C is the exemplary circuit diagram of signal conditioning unit of the invention.
Signal conditioning unit is made of three circuit units, i.e. bus current conditioning circuit shown in Fig. 8 A, shown in Fig. 8 B
Busbar voltage conditioning circuit and Fig. 8 C shown in sinusoidal magnitude conditioning circuit.
The working principle of bus current shown in Fig. 8 A (BUSI) conditioning circuit is, will be by the conducting resistance Ron and stream of Q5
Voltage I*Ron caused by bus current I through it (diode drop that the voltage is less than Q5) passes through first order amplifier
Isolation follow, using the amplification (amplification factor 1+R19/R17) of second level amplifier, eventually form bus current signal
BUSI=I*Ron* (1+R19/R17) is simultaneously transmitted to inversion control chip HT1156GP.The BUSI signal is transported using the third level
Input over-current signal OVERI is formed after putting the comparator of composition and is transmitted to fault detection circuit.The partial circuit has passed through
Use verifying.The cathode of diode D5 in Fig. 8 A is connected to the ground wire of inverting part circuit in Fig. 7 (with symbol AA mark in figure
Show).
In the busbar voltage conditioning circuit shown in Fig. 8 B, busbar voltage BUSV is busbar voltage PV-BUS by resistance point
Obtained after pressure, and be transferred directly to inversion control chip HT1156GP (in figure symbol BB indicate one end be connected to Figure 12 institute
The inversion control portion circuit shown).
The sinusoidal magnitude voltage SINV shown in Fig. 8 C is the sine voltage of inverting part output by isolating transformer
It is obtained after full-bridge rectification and electric resistance partial pressure again after (being shared with the second synchronization unit), and is sent to control chip
HT1156GP.The anode of voltage-stabiliser tube Z2 in Fig. 8 C is connected to protection circuit shown in Figure 13 (with symbol CC mark in figure).
Fig. 9 is the exemplary circuit diagram of third switch 38 and accessory power supply 39 of the invention.
In Fig. 9 dotted box portion be third switch 38 circuit, mainly include small-power NMOS tube Q6, voltage-stabiliser tube Z5 and
Diode D18.The effect of the partial circuit be control accessory power supply 39 starting and it is under-voltage shut down, starting accessory power supply 39
Condition is as follows:
(1) it just connects, i.e., the positive and negative terminals of the input terminal of the inverter of the embodiment of the present invention must connect correctly；
(2) voltage (i.e. busbar voltage PVBUS) of inverter input terminal is greater than VZ5, can just Q6 be made to be connected in this way；
(3) switch K3 is closed；
(4) voltage (i.e. busbar voltage) of inverter input terminal should be less than setting value 450V, can just make triode in this way
QQ6 conducting, accessory power supply control chip UC3843 could be worked normally.
Above four conditions must simultaneously meet, and accessory power supply 39 could start and work normally.
The inverter of the embodiment of the present invention is when exporting the sine wave of 220V, the open-circuit voltage V of input terminal photovoltaic moduleOC
It can be 380-450V, wherein volt component optimum operating voltage is 380*0.85-450*0.85V, i.e. 373-383V.
Accessory power supply 39 shown in Fig. 9 exports following No. four accessory power supply altogether:
+ 5V (label is in Fig. 9) is mainly inversion control chip HT1156GP, amplifier chip IR2110 (see Figure 12
In Vdd pin marked as 11) power supply；
+ 15V is amplifier chip IR2110 (see the Vcc pin in Figure 12 marked as 3) power supply；
K1V is first switch K1 power supply；
K2V is second switch K2 power supply.
Figure 10 A and Figure 10 B are respectively the exemplary circuit diagram of first switch K1 and second switch K2.
First switch K1 and second switch K2 is commutator, and wherein K1 is normally closed switch, and K2 is open type switch,
Two independences for being driven by two independent accessory power supply K1V and K2V, and being exported by inversion control chip HT1156GP respectively
Control signal K1 and K2 are controlled after light-coupled isolation.
Figure 11 A and Figure 11 B are respectively the exemplary circuit diagram of the first synchronization unit 33 and the second synchronization unit 34.
First synchronization unit 33 and this two parts circuit structure of the second synchronization unit 34 are different in addition to input and output tie point
Outer other structures are essentially identical, be the sine voltage signal that will input after transformer isolation, decompression again through rear end
Shaping circuit is transmitted to the first synchronization signal SYN1 pin of inversion control chip HT1156GP and the second synchronization signal SYN2 draws
Foot.
Figure 12 is the exemplary circuit diagram in inversion control portion.
Inversion control portion circuit is mainly made of inversion control chip HT1156GP and two amplifier chip IR2110.Pass through
It is same that the first synchronization signal SYN1 and second is received with the first synchronization signal SYN1 pin and the second synchronization signal SYN2 pin respectively
Signal SYN2 is walked, it is the first synchronization signal SYN1 or second synchronous that inversion control chip HT1156GP, which has identification synchronization signal,
The ability of signal SYN2, and there is the ability for determining whether the first synchronization signal SYN1 within the set time.
Figure 13 is short circuit, overcurrent and the thermal-shutdown circuit of the inverter of the embodiment of the present invention.
Wherein, output short circuit protection circuit is mainly by two triodes (QQ1, QQ2), two voltage-stabiliser tubes (Z3, Z4), four
Diode (D11, D12, D13 and D14) is constituted, its working principle is that, when output short-circuit, i.e., there is half in output inversion full-bridge
The switch element of bridge is straight-through, so that the junction voltage between D13 and D14 becomes low level, so that the collector of QQ3 be made to export
The SD signal SD pin of amplifier IR2110 (corresponding) become high level to turn off the output of amplifier IR2110, and make QQ4
Collector output FAILC signal become low level to turn off the output of inversion control chip HT1156GP, reach output it is short
The purpose of road protection.
Thermal-shutdown circuit is made of temperature detect switch (TDS) KT1 and a diode D15, and excess temperature signal is at the one end KT1
OVERT。
Current foldback circuit bus current conditioning circuit and the comparator circuit of its rear end shown in Fig. 8 A is constituted, overcurrent
Signal is the OVERI at the positive terminal of the diode D8 of comparator U11C output, which accesses two pole shown in Figure 13
Between pipe D13 and D14.
Three signal phases that above-mentioned output short circuit protection circuit, thermal-shutdown circuit and current foldback circuit export respectively with
(AND) the SD pin of a SD signal input amplifier IR2110, while SD signal shape after triode QQ4 reverse phase are formed afterwards
At the FAILC pin of FAILC signal input inversion control chip HT1156GP.
The present invention is not limited to above-mentioned specific embodiment, under without departing substantially from spirit of that invention and its real situation, is familiar with this
Field technical staff can make various corresponding change and modification according to the present invention, but these corresponding change and modification all should belong to this
Within invention scope of the appended claims.
Claims (12)
1. a kind of inverter for photovoltaic power generation, with ammeter terminal and face terminals, the ammeter terminal be used for
The two-way ammeter (20) for being connected to power grid (10) is connected, and the face terminals are used to connect the load of the inverter
(40), the inverter includes:
Inverting part (36) is connected to photovoltaic module (50) and is configured to for the DC power conversion that photovoltaic module (50) generate being positive
String alternating current wave；
First switch (31), is connected between ammeter terminal and face terminals, and the first switch is normally closed switch；
Second switch (32) is connected between inverting part (36) and face terminals, and the second switch is open type switch；
Inversion control portion (35) is connected to inverting part (36), first switch (31) and second switch (32), and is configured to control
Second switch (32) is connected when inverting part (36) start to work；
First synchronization unit (33) is connected between the ammeter terminal and inversion control portion (35), and is configured to detecting
The first synchronization signal (SYN1) is transmitted to inversion control portion (35) when being in power supply state to power grid (10),
Wherein, inversion control portion (35) are further configured to after start-up operation the predetermined time and inscribed are received in compliance with pre-provisioning request
Inverting part (36) are controlled when the first synchronization signal (SYN1) and work in grid-connect mode, are otherwise controlled first switch (31) and are disconnected and control
Inverting part (36) processed works in off-network mode,
Wherein, the grid-connect mode is that the inverter and power grid (10) are combined to load (40) power supply or the inversion
The operating mode that device is only powered to power grid (10) and load (40) to power grid (10) power supply or the inverter simultaneously,
The off-network mode is the operating mode that separate unit or the more inverters are only powered to load (40),
Wherein, inversion control portion (35) are further configured to the voltage and current institute according to the input terminal from the inverting part (36)
The sinusoidal magnitude that the busbar voltage (BUSV) and bus current (BUSI), the voltage from the face terminals of sampling are sampled
Voltage (SINV) calculates or selects the modulation degree for being ready to use in inverting part (36) prestored in real time, so that the inverter
MPPT maximum power point tracking is executed based on the first modulation degree when grid-connect mode work, is worked in separate unit inverter in off-network mode
When pressure stabilizing and current limliting executed based on the second modulation degree, and third tune is based on when more inverters are in off-network mode on-line working
System executes synchronization, pressure stabilizing and current limliting.
2. inverter as described in claim 1, which is characterized in that further include:
Second synchronization unit (34) is connected between the face terminals and inversion control portion (35), and is configured to when detection
When existing at the face terminals by with the inverter sine wave alternating current that similarly another inverter exports, to
Inversion control portion (35) transmits the second synchronization signal (SYN2),
Wherein, inversion control portion (35) are further configured to, and when inverting part to be controlled (36) works in off-network mode, are also controlled
The second switch (32) are closed,
Wherein, inversion control portion (35) are additionally configured to, and are receiving second synchronization signal (SYN2) for meeting pre-provisioning request
Single machine off-network mode or host off-network mode are worked in scheduled modulation degree control inverting part (36) before, met receiving
It is controlled according to modulation degree relevant to another inverter after second synchronization signal (SYN2) of pre-provisioning request
Inverting part (36) works in slave off-network mode,
Wherein, the single machine off-network mode is the mode that inverter described in separate unit is powered to the load (40), the host
Off-network mode is that the inverter guides other same inverters to described load (40) online power supply as host
Mode, the slave off-network mode be the inverter as slave under the guidance of another inverter to load
(40) mode of online power supply.
3. inverter as claimed in claim 2, which is characterized in that inversion control portion (35) are further configured to:
During inverting part (36) works in slave off-network mode, if in the current period knot of inverting part (36) output sine wave
After beam in the predetermined time, inversion control portion (35) be can't detect the second synchronization signal (SYN2), and the inverter is to make
For the inverter that can't detect the second synchronization signal (SYN2) in each inverter of the slave first, then the inversion control
Portion (35) processed stops detection the second synchronization signal (SYN2) and the inverting part (36) is made to work in host since next period
Off-network mode.
4. inverter as claimed in claim 2, which is characterized in that further include:
Signal conditioning unit (37) is connected to the face terminals, inverting part (36) and inversion control portion (35), in inverting part
(36) during working in single machine off-network mode or host off-network mode, the bus current (BUSI) and face terminals of inverting part (36)
The sinusoidal magnitude voltage (SINV) at place is transmitted to inversion control portion (35) after the signal conditioning unit (37) improve,
Wherein, inversion control portion (35) are further configured to the bus current after the signal conditioning unit (37) conditioning
(BUSI) it is at least once sampled with sinusoidal magnitude voltage (SINV) each cycle, and
When the bus current (BUSI) for determining sampling is not more than the first setting value, the modulation degree of inverting part (36) is adjusted until inverse
Become the reference voltage range that the sinusoidal magnitude voltage (SINV) that control unit (35) sample meets setting；
When the bus current (BUSI) for determining sampling is greater than first setting value and when less than the second setting value, Cycle by Cycle is reduced
The bus current (BUSI) that modulation degree for inverting part (36) is sampled until inversion control portion (35) is no more than described
First setting value；
When the bus current (BUSI) for determining sampling is greater than second setting value, inversion control portion (35) immediately turn off inversion
The output in portion (36) simultaneously disconnects second switch (32).
5. inverter as claimed in claim 2, which is characterized in that further include:
Signal conditioning unit (37) is connected to the face terminals, inverting part (36) and inversion control portion (35), in inverting part
(36) during working in slave off-network mode, the bus current (BUSI) and busbar voltage (BUSV) of inverting part (36) and described
The sinusoidal magnitude voltage (SINV) of the existing sine wave alternating current by another inverter output passes through at face terminals
Inversion control portion (35) are transmitted to after crossing signal conditioning unit (37) conditioning,
Inversion control portion (35) is additionally configured to during control inverting part (36) works in slave off-network mode, to by signal tune
Sinusoidal magnitude voltage (SINV), bus current (BUSI) and busbar voltage (BUSV) after reason unit (37) conditioning are adopted
Sample determines described according to the ratio between the sinusoidal magnitude voltage (SINV) of present sample and busbar voltage (BUSV)
The modulation degree in inverting part (36) next period, and second synchronization signal generated according to second synchronization unit (34)
(SYN2) start to export sine wave to start inverting part (36).
6. inverter as claimed in claim 5, which is characterized in that inversion control portion (35) are further configured to:
During the bus current (BUSI) for determining sampling is not more than the first setting value, inversion control portion (35) each cycle weight
The process of the modulation degree in the multiple above-mentioned determination inverting part (36) next period；
When the bus current (BUSI) for determining sampling is greater than first setting value and when less than the second setting value, inversion control
Portion's (35) Cycle by Cycle processed reduces the modulation degree for being used for inverting part (36), until the bus electricity that inversion control portion (35) sample
It flows (BUSI) and is not more than first setting value；
When the bus current (BUSI) for determining sampling is greater than second setting value, inversion control portion (35) immediately turn off inversion
The output in portion (36) simultaneously disconnects second switch (32).
7. inverter as described in claim 1, which is characterized in that further include:
Signal conditioning unit (37) is connected to the face terminals, inverting part (36) and inversion control portion (35), the load
The sinusoidal magnitude voltage (SINV) of the sine wave alternating current of power grid existing at terminal (10) and the bus electricity of inverting part (36)
Pressure (BUSV) is transmitted to inversion control portion (35) after signal conditioning unit (37) conditioning,
Inversion control portion (35) is further configured to receiving first synchronization signal (SYN1) and receiving first same
When step signal (SYN1) meets scheduled frequency range, to the sinusoidal magnitude voltage after signal conditioning unit (37) conditioning
(SINV) it is sampled with busbar voltage (BUSV), meets scheduled voltage range in the sinusoidal magnitude voltage (SINV)
When, it is determined according to the ratio between the sinusoidal magnitude voltage (SINV) of present sample and the busbar voltage (BUSV)
The modulation degree in the inverting part (36) next period, and inverting part is controlled according to the modulation degree and the first synchronization signal (SYN1)
(36) grid-connect mode is worked in.
8. inverter as claimed in claim 7, it is characterised in that:
During inverting part (36) works in grid-connect mode, the bus current (BUSI) of inverting part (36), busbar voltage (BUSV)
Inversion control is transmitted to after signal conditioning unit (37) conditioning with the sinusoidal magnitude voltage (SINV) at the face terminals
Portion (35) processed,
Wherein, inversion control portion (35) are further configured to:
When the bus current (BUSI) for determining sampling is greater than the second setting value, inversion control portion (35) immediately turn off inversion
The output in portion (36) simultaneously disconnects second switch (32)；
When the bus current (BUSI) for determining sampling is not more than second setting value, inversion control portion (35) are configured to
Following procedure is executed to determine maximum power point Pn+s,
Inversion control portion (35) calculates the product P of current busbar voltage and bus currentn=BUSIn*BUSVn, then towards the positive direction and
Modulation degree is changed Δ M by a direction in negative sense, and under modulation degree after the change, then calculates the busbar voltage of resampling
With the product P of bus currentn+1=BUSIn+1*BUSVn+1,
If Pn+1>Pn, then inversion control portion (35) continue that current modulation degree is changed Δ M until P again in the same directionn+s
≥Pn+s+1Until, no longer change modulation degree,
If Pn+1<Pn, then inversion control portion (35) towards it is described positively and negatively in another direction by current modulation degree again
Change Δ M until Pn+s≥Pn+s+1, until, no longer changing modulation degree, wherein s is the number that modulation degree is changed to Δ M,
Inversion control portion (35) is used corresponding to current maximum power point Pn+sModulation degree and the first synchronization signal (SYN1) control
The output of inverting part (36) processed.
9. inverter as claimed in claim 8, which is characterized in that inversion control portion (35) are further configured to:
In inverting part (36) to correspond to the maximum power point P being recently determinedn+sModulation degree carry out sinewave output during, it is inverse
Become the synchronization of control unit (35) in each period of the sinewave output and samples and store the bus current (BUSI), mother
Line voltage (BUSV) and sinusoidal magnitude voltage (SINV), and calculate separately and sampled described in two of acquisition in this way in adjacent periods
The second absolute difference between the first absolute difference, two busbar voltages (BUSV) between bus current (BUSI) and two are just
Third absolute difference between string wave amplitude threshold voltage (SINV), whenever any of described first to third absolute difference even
When being not less than setting value in the continuous predetermined period, the inversion control portion (35) executes above-mentioned determining maximum power point P againn+s
Process and with the first synchronization signal (SYN1) and with again determine current maximum power point Pn+sCorresponding modulation degree controls
The output of inverting part (36).
10. inverter as described in claim 1, which is characterized in that further include:
Signal conditioning unit (37) is connected to the face terminals and inversion control portion (35), occurs at the face terminals
Power grid (10) sine wave alternating current sinusoidal magnitude voltage (SINV) by signal conditioning unit (37) conditioning after transmit
To inversion control portion (35),
The inversion control portion (35) is further configured to:
During inverting part (36) works in off-network mode, meet when receiving first synchronization signal (SYN1) and receiving
The first synchronization signal (SYN1) of pre-provisioning request, the sinusoidal magnitude voltage (SINV) meets scheduled voltage range simultaneously
When, the inversion control portion (35) control closure first switch (31) and control inverting part (36) be switched to work in it is described grid-connected
Mode.
During inverting part (36) works in grid-connect mode, when no longer receiving the first synchronization signal (SYN1), when connecing
When the first synchronization signal (SYN1) received does not meet pre-provisioning request or when the sinusoidal magnitude voltage (SINV) is unsatisfactory for
When scheduled voltage range, control, which disconnects first switch (31) and controls inverting part (36) and be switched to, works in the off-network mould
Formula.
11. inverter as described in claim 1, which is characterized in that further include:
Third switchs (38), and one end is connected between photovoltaic module (50) and inverting part (36), and the other end is connected to described
The accessory power supply of inverter, it is manual switch that third, which switchs (38),.
12. inverter as described in claim 1, which is characterized in that the inversion control portion (35) uses MCU, DSP, SOC
Or the inversion control chip of model HT1156GP is realized.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811278462.4A CN109193789B (en) | 2018-10-30 | 2018-10-30 | Inverter for photovoltaic power generation |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201811278462.4A CN109193789B (en) | 2018-10-30 | 2018-10-30 | Inverter for photovoltaic power generation |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN109193789A true CN109193789A (en) | 2019-01-11 |
| CN109193789B CN109193789B (en) | 2021-12-14 |
Family
ID=64940695
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201811278462.4A Active CN109193789B (en) | 2018-10-30 | 2018-10-30 | Inverter for photovoltaic power generation |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN109193789B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109638795A (en) * | 2019-01-16 | 2019-04-16 | 厦门科华恒盛股份有限公司 | String type photovoltaic inverting system emergency stop control method and device |
| CN109842154A (en) * | 2019-02-18 | 2019-06-04 | 阳光电源股份有限公司 | A kind of means of relay controlling and device of gird-connected inverter |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8269374B2 (en) * | 2010-03-04 | 2012-09-18 | De Caires Damian | Solar panel power management system and method |
| CN203014394U (en) * | 2012-12-21 | 2013-06-19 | 武汉承光博德光电科技有限公司 | Household photovoltaic multifunctional intelligent power station |
| CN104362670A (en) * | 2014-10-21 | 2015-02-18 | 上海电机学院 | Non-schedulable solar power generation and mains supply complementary system |
| CN106026167A (en) * | 2016-06-24 | 2016-10-12 | 国家电网公司 | Distributed power source grid connected access device |
| CN205811557U (en) * | 2016-07-13 | 2016-12-14 | 保定英利分布式能源股份有限公司 | Grid-connected superposition electricity generation system for communication base station |
| CN106329568A (en) * | 2016-08-31 | 2017-01-11 | 湖北大学 | User-commercial type photovoltaic generation economic dispatching control system |
| CN107925246A (en) * | 2015-08-14 | 2018-04-17 | 光城公司 | Multiple inverter power control systems in energy production system |
-
2018
- 2018-10-30 CN CN201811278462.4A patent/CN109193789B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8269374B2 (en) * | 2010-03-04 | 2012-09-18 | De Caires Damian | Solar panel power management system and method |
| CN203014394U (en) * | 2012-12-21 | 2013-06-19 | 武汉承光博德光电科技有限公司 | Household photovoltaic multifunctional intelligent power station |
| CN104362670A (en) * | 2014-10-21 | 2015-02-18 | 上海电机学院 | Non-schedulable solar power generation and mains supply complementary system |
| CN107925246A (en) * | 2015-08-14 | 2018-04-17 | 光城公司 | Multiple inverter power control systems in energy production system |
| CN106026167A (en) * | 2016-06-24 | 2016-10-12 | 国家电网公司 | Distributed power source grid connected access device |
| CN205811557U (en) * | 2016-07-13 | 2016-12-14 | 保定英利分布式能源股份有限公司 | Grid-connected superposition electricity generation system for communication base station |
| CN106329568A (en) * | 2016-08-31 | 2017-01-11 | 湖北大学 | User-commercial type photovoltaic generation economic dispatching control system |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109638795A (en) * | 2019-01-16 | 2019-04-16 | 厦门科华恒盛股份有限公司 | String type photovoltaic inverting system emergency stop control method and device |
| CN109842154A (en) * | 2019-02-18 | 2019-06-04 | 阳光电源股份有限公司 | A kind of means of relay controlling and device of gird-connected inverter |
Also Published As
| Publication number | Publication date |
|---|---|
| CN109193789B (en) | 2021-12-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4076721B2 (en) | Isolated power-proof method and apparatus for distributed generation | |
| US20180175623A1 (en) | Smart and on/off-grid power inverters | |
| CN201238200Y (en) | Intelligent generator set for uninterrupted power supply | |
| CN101123349A (en) | Island effect detection method based on active frequency deviation and its device | |
| CN107689642A (en) | Poewr control method, device, inverter apparatus and plant controller | |
| CN109490638A (en) | The impedance measurement formula isolated island detection method of the grid-connected direct current power system of more photo-voltaic power supplies | |
| CN104655990A (en) | Medium and low-voltage power distribution network simulation system based on energy feedback | |
| CN1937349A (en) | Comprehensive dynamic compensating device for distribution network | |
| CN109193789A (en) | A kind of inverter for photovoltaic power generation | |
| CN105717399A (en) | Test device for power grid adaptability | |
| CN210468801U (en) | Special dual-power non-sensing switching cabinet for bypass live working of 0.4kV branch box | |
| CN201045748Y (en) | Ups | |
| CN105826909A (en) | Charging circuit for converters, converter, and air conditioner | |
| JP2014050292A (en) | Distributed power supply system, and autonomous operation control device | |
| CN104009652A (en) | Portable direct-current power supply | |
| CN205791503U (en) | Charging circuit, inverter and air-conditioning in a kind of inverter | |
| CN110967576A (en) | Anti-islanding operation detection method under distributed power supply grid-connected mode | |
| CN206945802U (en) | A kind of packaged type control power supply in power plant or intelligent substation | |
| KR101384727B1 (en) | A Multifunction device for simulated driving of grid connected system and control method for it | |
| CN109946560A (en) | The current transformer polarity adaptive approach of photovoltaic DC-to-AC converter | |
| CN212649106U (en) | AC/DC power supply device | |
| CN205725557U (en) | A kind of feeder reactance voltage disturbance power-supply system | |
| CN208112242U (en) | A kind of autocompensation installation based on PLC control | |
| CN108418227A (en) | A kind of autocompensation installation and its compensation method based on PLC controls | |
| CN111697587A (en) | AC/DC power supply device |
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 | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20211029 Address after: 100043 room 1102, building 6, courtyard 9, Gucheng Greenland Financial City, Shijingshan District, Beijing Applicant after: Harmotech Beijing Co.,Ltd. Address before: 461000 East office, 1st floor, north courtyard, Weidu high tech Industrial Park, Hongteng Road, Xuchang City, Henan Province Applicant before: HENAN XUXIN FREQUENCY CONVERSION TECHNOLOGY RESEARCH INSTITUTE Co.,Ltd. |
|
| GR01 | Patent grant | ||
| GR01 | Patent grant |