WO2010130273A1 - Device to extract maximum power from a solar array and process to carry it out - Google Patents
Device to extract maximum power from a solar array and process to carry it out Download PDFInfo
- Publication number
- WO2010130273A1 WO2010130273A1 PCT/EP2009/003376 EP2009003376W WO2010130273A1 WO 2010130273 A1 WO2010130273 A1 WO 2010130273A1 EP 2009003376 W EP2009003376 W EP 2009003376W WO 2010130273 A1 WO2010130273 A1 WO 2010130273A1
- Authority
- WO
- WIPO (PCT)
- Prior art keywords
- power
- current
- regulator
- solar array
- mppc
- Prior art date
Links
Classifications
-
- 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
- H02J3/00—Circuit arrangements for ac mains or ac distribution networks
- H02J3/38—Arrangements for parallely feeding a single network by two or more generators, converters or transformers
-
- 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
Definitions
- the object of the present invention is a device able to extract the maximum of energy from a solar array and to transfer it, into a grid with the highest possi- 10 ble efficiency. It is also the object of the invention a process to extract the maximum energy from a solar array with the device of the invention.
- the device object of the invention consist of a 15 Modular Non Dissipative Switching Regulator which delivers DC power at its maximum Power Point (MPP) and an Inverter Module.
- MPP Maximum Power Point
- the Modular Non Dissipative Switching Regulator 20 has as its mam feature the fact of being Modular, that is, it allows to get access to the power available from each of the n branches of the solar array as the voltage and the current from each branch is measured continuously. 25
- the inverter module comprises a Current Controlled Non Dissipative Series Switching Regulator able to convert DC power supplied by the Modular Switching regulator into AC power, and a H-bridge Power Inverter.
- the device it could comprise an ad ⁇ ditional module which would be a Bidirectional switching series regulator which would allow the transfer for AC power to a storage module when the power provided is greater than the grid power or transferring AC power from storage module to the Current controlled Switching regulator when the grid power is greater to the power supplied.
- This Bidirectional Switching Regulator would be connected in parallel to the Modular Switching Regulator and the Current Controlled Switching Regulator.
- Characterized the present invention the special features which the elements which form part of the object of the invention present m order to get at least a maximum extraction of energy from a solar array.
- a solar array is operated to its MPP perman- ently and to it is got from it a DC power, without any
- This power is the sum of powers available from n solar panel branches mounted in parallel to form the solar array.
- -Storing of the difference between the DC and the AC power in a non dissipative element and the difference power can be used to be injected into the grid or/and into another electrical network feeding non grid users.
- This module has the objective to maintain the power efficiency of the inverter as high as possible.
- - Managing always the solar array to its optimum energy configuration in case where anomalies or failures are detected in the n solar panel branches.
- MPPT-Inverter which stands for Maximum Power Point Tracker and referred as MPPT, which is an electronic system that opera- tes PV Modules in a manner that allows the modules to produce all the power they are capable of.
- MPPT is not a mechanical tracking system that "physically" moves the modules to make them point more directly at the sun.
- MPPT is a fully electronic system that varies the elec- trical operating point of the modules so that the modules are able to deliver maximum available power.
- MPPT corresponds to a unit that transfers to the grid the maximum power possible from a solar array. This amount of power is the result of a tracking process, called MPPT (Maximum Power Point Tracking) , which is achieved by measuring permanently, according to a sampling process kT, the voltage v k and the current i k of the solar array, make the product that is the power p k at sampling time t* and compare this result at time tk + i by moving the operating point of a series regulator connected to the solar array. Depending on the sign of the difference p k+ ⁇ - p k the series regulator continue to move the operating point in one direction or its opposite. This power is supposed to be the maximum available from a solar array. It is exact if all panels of the solar array operate in the same conditions of light, temperature and ageing.
- the n branches of the solar array are first paralleled before to be connected to a MPPT non dissipative series switching regulator.
- This regu- lator controls its input voltage and forces the PV module to operate at a voltage v k and measures the available current i k . It moves this voltage by steps until a change of sign in the measured power difference is detected. It is the MPPT process.
- the regulator delivers the power to the inverter module, under the form of a variable current as the inverter module imposes a DC voltage to the output of the MPPT regulator.
- the inverter module is composed of two regula- tors.
- the first one is a series non dissipative regulator which behaves as a current source delivering an AC current, having the same phase as the AC grid voltage, to a H bridge power cell.
- This H bridge is connected to the grid via an insulating transformer for low power transfer or directly for high power transfer. In this last case, the insulation transformer is transferred into the current control regulator, generally under the form of a push-pull power cell.
- MPPT-Inverter device does not allow to have access to the power from each of the n-branches of a solar array, happening sometimes that one or even more of the modules of the solar array, for instance, have a short-circuit, not being possible to know if the are contributing or not to the maximum power.
- MPPT-Inverter Another drawback which can be found in the devi- ces used up to now and known as MPPT-Inverter is derived from the lack of correlation between the power supplied and grid power, lacking of any means for absorbing, or supplying the difference of power between the power supplied and the grid power.
- the object of the invention is to design a device able to extract the maximum of energy from a solar array and to transfer it, into a grid with the highest possible efficiency.
- the device object of the invention consist of a Modular Non Dissipative Switching Regulator which delivers DC power at its maximum Power Point (MPP) , which will be referenced as MPPC (Maximum Power Point Control) and an Inverter Module.
- MPP maximum Power Point
- MPPC Maximum Power Point Control
- the principle of the MPPC is to replace the MPPT process by the MPPC process in a first step.
- the modular feature of this process allows to get access to the power available from each of the n branches of the solar array as the voltage and the current from each branch is measured continuously. An anomaly happening to one of these n branches is immediately detected and corrective actions may be taken.
- the main difference with the MPPT Inverter comes from the evaluation of the energy performance of each branch which are managed by a dedicated channel of a modular non dissipative sequential switching shunt regulator, called S3R.
- S3R modular non dissipative sequential switching shunt regulator
- the n channels of the regulator force the solar array to operate at its MPP. If one branch is not contributing to the maximum power, due to a short circuit for instance, it can be disconnected from the rest and its status be sent to a central management controller.
- the efficiency of the S3R is almost 100% as only one channel is involved in the voltage regulation with a reduced duty cycle while the n-1 other transfer the power to the inverter module.
- a Current Controlled Series regulator (CCSR) is now connected to the MPPC-S3R module which delivers a DC power, the MPP power.
- a Current Controlled Series regulator able to convert this DC power into AC power is necessary and sufficient. In case such a regulator is not available it must be connected also to a Bidirectional Switching Series regulator mounted in parallel between the MPPC-S3R and the Current Contolled Series regulator.
- the task of this additional module is to allow the transfer of an AC power to the grid while a DC power is available from the S3R.
- the power difference has an AC form, similar to the one transferred to the grid. It is transferred to an energy storage module, equivalent to a battery, when the MPP power is greater than the grid power. It is transferred to the Current Controlled regulator connected to the H bridge when the grid power is greater than the MPP power.
- an insulating trans- former is inserted between the H bridge and the grid for low power application or inside the current controller, via a push-pull power cell for high power applications.
- the device object of the invention consists of two modules a MPPC, referenced as MPPC-S3R module and an Inverter module.
- the MPPC-S3R module is a modular shunt regulator with as many channels as they are solar panels to be managed. It is a S3R regulator with n channels, each channel connected to a solar panel via power cell composed of a shunt power switch Q n and a series power diode D n . The n power cells are connected to a common capacit- ive output filter C.
- This regulator regulates the MPP voltage of the solar array (or the n solar panels) according to a reference command Vmpp generated by a microprocessor.
- the microprocessor computes the MPP of the solar array using the measurements of the i n current coming from each solar panel, the solar array voltage v and the status of the power switches Q n .
- Figure 1 shows a Block diagram of a MPPT-Inver- ter
- Figure 2 represents a block diagram of the devi- ce object of the invention, that is, a MPPC-Inverter
- FIG. 3 represents a detailed circuit of this MPPC-S3R module
- Figure 4 represents a theoretical block diagram of the inverter module of the MPPC-Inverter unit.
- Figures 5A, 5B and 5C represent the waveforms of the grid parameters at IkW MPP power.
- Figure 6 represents power ripple at input of the Current Controlled Series Regulator.
- FIG. 7 shows a block diagram of the Current Controlled Series Regulator CCSR.
- FIG 8 shows a detailed block diagram of the MPPC-S3R Inverter with active filter.
- the device of the invention basically consists of a MPPC module referenced as a MPPC-S3R and an inver- ter module, both combined seek to extract the maximum of energy from a solar array and to transfer it, into a grid with the highest possible efficiency.
- FIG 2 it can be observed a block diagram of the device object of the invention wherein it is possible identified the MPPC-S3R module and the Inverter Module and the elements which form part of the same.
- FIG. 3 A detailed circuit of this MPPC-S3R module is shown on fig 3 where 3 solar panel modules are connected to a 3 channels switching shunt regulator. The load corresponds to the inverter module.
- the MPPC-S3R module is a modular shunt regulator with as many channels as they are solar panels to be managed. It is a S3R regulator with n channels, each channel connected to a solar panel via power cell composed of a shunt power switch Q n and a series power diode D n . The n power cells are connected to a common capacit- ive output filter C.
- This regulator regulates the MPP voltage of the solar array (or the n solar panels) according to a reference command V RMPP generated by a microprocessor.
- the microprocessor computes the MPP of the solar array using the measurements of the i n current com- ing from each solar panel, the solar array voltage v and the status of the power switches Q n .
- the inverter module is composed of a Current Controlled Series Regulator (CCSR) connected in series with a H- bridge power inverter.
- CCSR Current Controlled Series Regulator
- the grid voltage v AC is imposed to the output of the Current Controlled Series Regulator. It is given by:
- V AC V M cos ⁇ t
- the Current Controlled Series Regulator has to deliver to the H bridge a variable current i O ut able to be transferred to the grid under a sinus waveform having the same phase as the voltage v AC .
- It cor ⁇ responds a sinus current waveform with a peak value I M (half of the peak to peak value) such as:
- the current x out to be delivered by the CCSR corresponds to the absolute values of the grid current i AC that is:
- the waveform of the current i out is shown on fig 5B.
- the power P AC delivered to the grid is given on fig 5c. It corresponds to the relationship:
- variable delivered power P AC is available at the input of the Current Controlled Series Regulator which receives a constant power, the MPP power P M pp-
- the ripple shown in figure 6 may be filtered passively by a huge reactive filter composed by a capacitance C or an LC filter. It leads to a heavy and massive filter. It cannot be suppressed the voltage ripple v on the capacitance terminals.
- the worst case is given by:
- a ripple of IV for an application where VW is around 400V and P MPP is IkW will require a capacitance C of several thousands of F.
- the Current Controlled Series Regulator is necessary to generate the current i out as shown on fig 5B. Its output voltage v out is imposed by the grid. Trans- ferred by the H-Bridge this voltage is a positive half sinus waveform.
- This regulator can be buck or boost type such as the output current is controlled by a command v such as, if G is a constant and G M pp a parameter dependent on VW and v out :
- the output of the Comparator changes sign and the Logic circuit which has switched on Q A according to a clock generator, switches off Q A and switches on Q 3 .
- the Logic circuit which has switched on Q A according to a clock generator, switches off Q A and switches on Q 3 .
- the output current must have a half sinus positive waveform with a peak value I M dependent on I M PP in order that the same quantity of electricity is exchanged in the input of the regulator that is:
- the command Gv(t) is realised by a microprocessor which receives inputs from :
- the voltage Gv (t) is the output voltage provided by a microprocessor which amplifies Ia difference between the current going to the inverter and the current coming from the S3R. It is a control command which defines the upper limit of the switching current enter- ing the inverter. And as it can be observed in figure 7 depending of the difference between Gv (t) and I M , the CCSR will work as a buck or as a boost type regulator, activitmg either Q A or Q B .
- On fig 8 is detailed the block diagram of the complete MPPC-S3R Inverter with the active filter.
- This filter is a bidirectional current controlled regulator. It operates as a buck to transfer power from the S3R to the capacitance C 5 and as a boost to send power to the inverter.
- the switches of the regulator are Q A ⁇ and Q B ⁇ .
- the principle is the same as the Current Controlled Series Regulator.
- the saw tooth current 2 s (t) flowing into switch Q AS is sensed and compared to an analogue command Gv 5 .
- This current is positive in the buck operation (power to the capacitance C 5 ) and negative in the boost mode (power to the CCSR) .
- the switch is activated by a clock via the Logic circuit and the driver, and switched off when the comparator changes state that is:
- the current m the inductance L 3 is controlled by a feedback loop which compares it to a variable reference current via an Error Amplifier which generates the command Gv 5
- This variable reference is the result of a comparison of the MPP current I MPP with the inverter current I entering the Current Controlled Series Regulator via an Amplifier.
- an LC filter is inserted between the S3R and the inverter.
Abstract
The device consist of a Modular Non Dissipative Switching Regulator (MPPC-S3R) which delivers DC power at its maximum Power Point (MPP) and an Inverter Module, wherein the MPPC-S3R is modular allowing to get access to the power available from each of the n branches of the solar array as the voltage and the current from each branch is measured continuously; the inverter comprises a Current Controlled Non Dissipative Series Switching Regulator (CCSR) able to convert DC power supplied by the Modular Switching regulator into AC power, and a H-bridge Power Inverter, and it also comprises a Bidirectional switching series regulator which would allow the transfer for AC power to a storage module when the power provided is greater than the power demanded by the grid or transferring AC power from storage module to the Current controlled Switching regulator when the power demanded by grid is greater than the power supplied. This allows the highest possible efficiency maintaining the efficiency of the inverter as high as possible while detecting anomalies in any of the n-branches of a solar array.
Description
DEVICE TO EXTRACT MAXIMUM POWER FROM A SOLAR ARRAY AND PROCESS TO CARRY IT OUT
5 OBJECT OF THE INVENTION
The object of the present invention is a device able to extract the maximum of energy from a solar array and to transfer it, into a grid with the highest possi- 10 ble efficiency. It is also the object of the invention a process to extract the maximum energy from a solar array with the device of the invention.
The device object of the invention consist of a 15 Modular Non Dissipative Switching Regulator which delivers DC power at its maximum Power Point (MPP) and an Inverter Module.
The Modular Non Dissipative Switching Regulator 20 has as its mam feature the fact of being Modular, that is, it allows to get access to the power available from each of the n branches of the solar array as the voltage and the current from each branch is measured continuously. 25
The inverter module comprises a Current Controlled Non Dissipative Series Switching Regulator able to convert DC power supplied by the Modular Switching regulator into AC power, and a H-bridge Power Inverter. 30
Additionally the device it could comprise an ad¬ ditional module which would be a Bidirectional switching series regulator which would allow the transfer for AC power to a storage module when the power provided is
greater than the grid power or transferring AC power from storage module to the Current controlled Switching regulator when the grid power is greater to the power supplied.
This Bidirectional Switching Regulator would be connected in parallel to the Modular Switching Regulator and the Current Controlled Switching Regulator.
Characterized the present invention the special features which the elements which form part of the object of the invention present m order to get at least a maximum extraction of energy from a solar array.
Thanks to the elements which form part of the device and the functions they performs some objectives are achieved, as the following:
- A solar array is operated to its MPP perman- ently and to it is got from it a DC power, without any
AC ripple coming from a tracking process. This power is the sum of powers available from n solar panel branches mounted in parallel to form the solar array.
-Conversion of the DC power into into AC power in a suitable form to be inserted in a grid network with an efficiency the highest possible.
-Storing of the difference between the DC and the AC power in a non dissipative element and the difference power can be used to be injected into the grid or/and into another electrical network feeding non grid users. This module has the objective to maintain the power efficiency of the inverter as high as possible.
- Managing always the solar array to its optimum energy configuration in case where anomalies or failures are detected in the n solar panel branches.
- Informing a central control tower about the operational status of each branch of the solar array and identify the panels which may require maintenance.
- conversion of the DC maximum power available from a solar array into AC power to be injected into the grid with the highest efficiency.
BACKGROUND OF THE INVENTION
The state of the art is called MPPT-Inverter, which stands for Maximum Power Point Tracker and referred as MPPT, which is an electronic system that opera- tes PV Modules in a manner that allows the modules to produce all the power they are capable of. MPPT is not a mechanical tracking system that "physically" moves the modules to make them point more directly at the sun. MPPT is a fully electronic system that varies the elec- trical operating point of the modules so that the modules are able to deliver maximum available power.
MPPT corresponds to a unit that transfers to the grid the maximum power possible from a solar array. This amount of power is the result of a tracking process, called MPPT (Maximum Power Point Tracking) , which is achieved by measuring permanently, according to a sampling process kT, the voltage vk and the current ik of the solar array, make the product that is the power pk at sampling time t* and compare this result at time tk+i by
moving the operating point of a series regulator connected to the solar array. Depending on the sign of the difference pk+ι - pk the series regulator continue to move the operating point in one direction or its opposite. This power is supposed to be the maximum available from a solar array. It is exact if all panels of the solar array operate in the same conditions of light, temperature and ageing.
The general block diagram of a MPPT-Inverter, connected to a solar array of n sub panel modules, is represented on figl. The n branches of the solar array are first paralleled before to be connected to a MPPT non dissipative series switching regulator. This regu- lator controls its input voltage and forces the PV module to operate at a voltage vk and measures the available current ik. It moves this voltage by steps until a change of sign in the measured power difference is detected. It is the MPPT process. The regulator delivers the power to the inverter module, under the form of a variable current as the inverter module imposes a DC voltage to the output of the MPPT regulator.
The inverter module is composed of two regula- tors. The first one is a series non dissipative regulator which behaves as a current source delivering an AC current, having the same phase as the AC grid voltage, to a H bridge power cell. This H bridge is connected to the grid via an insulating transformer for low power transfer or directly for high power transfer. In this last case, the insulation transformer is transferred into the current control regulator, generally under the form of a push-pull power cell.
One disadvantage of the MPPT-Inverter device is that does not allow to have access to the power from each of the n-branches of a solar array, happening sometimes that one or even more of the modules of the solar array, for instance, have a short-circuit, not being possible to know if the are contributing or not to the maximum power.
Another drawback which can be found in the devi- ces used up to now and known as MPPT-Inverter is derived from the lack of correlation between the power supplied and grid power, lacking of any means for absorbing, or supplying the difference of power between the power supplied and the grid power.
Therefore it is an object of the present invention to overcome the drawbacks detected up to now, designing a device which would allow detection of any anomaly happened in any of the n-branches of a solar array and which would have means for absorbing or supplying the difference of power between the power supplied from the solar array and grid power.
EXPLANATION OF THE INVENTION
The object of the invention is to design a device able to extract the maximum of energy from a solar array and to transfer it, into a grid with the highest possible efficiency.
The device object of the invention consist of a Modular Non Dissipative Switching Regulator which delivers DC power at its maximum Power Point (MPP) , which will be referenced as MPPC (Maximum Power Point Control) and an Inverter Module.
The principle of the MPPC is to replace the MPPT process by the MPPC process in a first step. The modular feature of this process allows to get access to the power available from each of the n branches of the solar array as the voltage and the current from each branch is measured continuously. An anomaly happening to one of these n branches is immediately detected and corrective actions may be taken.
The main difference with the MPPT Inverter comes from the evaluation of the energy performance of each branch which are managed by a dedicated channel of a modular non dissipative sequential switching shunt regulator, called S3R. The n channels of the regulator force the solar array to operate at its MPP. If one branch is not contributing to the maximum power, due to a short circuit for instance, it can be disconnected from the rest and its status be sent to a central management controller. The efficiency of the S3R is almost 100% as only one channel is involved in the voltage regulation with a reduced duty cycle while the n-1 other transfer the power to the inverter module.
Another difference with the state of the art re- presented by the combination MPPT-Inverter concerns the inverter module. A Current Controlled Series regulator (CCSR) is now connected to the MPPC-S3R module which delivers a DC power, the MPP power. A Current Controlled Series regulator able to convert this DC power into AC power is necessary and sufficient. In case such a regulator is not available it must be connected also to a Bidirectional Switching Series regulator mounted in parallel between the MPPC-S3R and the Current Contolled Series regulator. The task of this additional module is to allow the transfer of an AC power to the grid while a
DC power is available from the S3R. The power difference has an AC form, similar to the one transferred to the grid. It is transferred to an energy storage module, equivalent to a battery, when the MPP power is greater than the grid power. It is transferred to the Current Controlled regulator connected to the H bridge when the grid power is greater than the MPP power.
As for the MPPT inverter, an insulating trans- former is inserted between the H bridge and the grid for low power application or inside the current controller, via a push-pull power cell for high power applications.
The device object of the invention consists of two modules a MPPC, referenced as MPPC-S3R module and an Inverter module.
The MPPC-S3R module is a modular shunt regulator with as many channels as they are solar panels to be managed. It is a S3R regulator with n channels, each channel connected to a solar panel via power cell composed of a shunt power switch Qn and a series power diode Dn. The n power cells are connected to a common capacit- ive output filter C. This regulator regulates the MPP voltage of the solar array (or the n solar panels) according to a reference command Vmpp generated by a microprocessor. The microprocessor computes the MPP of the solar array using the measurements of the in current coming from each solar panel, the solar array voltage v and the status of the power switches Qn.
The inverter module converts the DC voltage at the output of the MPPC-S3R module into AC current such as the MPP power is totally transferred to the grid. If iMPp and vMPP and are the delivered current and voltage de-
livered by the MPPC-S3R and iAC is the AC current transferred to the grid at the imposed voltage vAC, that is 220V rms at the frequency f= /2 that is 50 Hz, the MPP power PMPp is such as:
"MPP ~ VAClAC ~ V MPP1I MPP
EXPIANATION OF THE FIGUKES
Further characteristics and advantages of the invention will be explained in greater detail in the following detailed description of an embodiment thereof which is given by way of non-limiting example with reference to the appended drawings, in which:
Figure 1, shows a Block diagram of a MPPT-Inver- ter
Figure 2 represents a block diagram of the devi- ce object of the invention, that is, a MPPC-Inverter
Figure 3, represents a detailed circuit of this MPPC-S3R module
Figure 4, represents a theoretical block diagram of the inverter module of the MPPC-Inverter unit.
Figures 5A, 5B and 5C, represent the waveforms of the grid parameters at IkW MPP power.
Figure 6, represents power ripple at input of the Current Controlled Series Regulator.
Figure 7, shows a block diagram of the Current
Controlled Series Regulator CCSR.
Figure 8, shows a detailed block diagram of the MPPC-S3R Inverter with active filter.
PREFERRED EMBODIMENT OF THE INVENTION
The device of the invention basically consists of a MPPC module referenced as a MPPC-S3R and an inver- ter module, both combined seek to extract the maximum of energy from a solar array and to transfer it, into a grid with the highest possible efficiency.
In figure 2 it can be observed a block diagram of the device object of the invention wherein it is possible identified the MPPC-S3R module and the Inverter Module and the elements which form part of the same.
A detailed circuit of this MPPC-S3R module is shown on fig 3 where 3 solar panel modules are connected to a 3 channels switching shunt regulator. The load corresponds to the inverter module.
The MPPC-S3R module is a modular shunt regulator with as many channels as they are solar panels to be managed. It is a S3R regulator with n channels, each channel connected to a solar panel via power cell composed of a shunt power switch Qn and a series power diode Dn. The n power cells are connected to a common capacit- ive output filter C. This regulator regulates the MPP voltage of the solar array (or the n solar panels) according to a reference command VRMPP generated by a microprocessor. The microprocessor computes the MPP of the solar array using the measurements of the in current com- ing from each solar panel, the solar array voltage v and
the status of the power switches Qn.
The inverter module converts the DC voltage at the output of the MPPC-S3R module into AC current such as the MPP power is totally transferred to the grid. If iMPP and vMPP and are the delivered current and voltage delivered by the MPPC-S3R and iΛC is the AC current transferred to the grid at the imposed voltage vAC, that is 220V rms at the frequency £=ω/2π that is 50 Hz, the MPP power PMpP is such as:
"MPP = VAClAC ~ V MPP1MPP
This transfer is represented by the block diagram given on fig4, wherein it can be observed that the inverter module is composed of a Current Controlled Series Regulator (CCSR) connected in series with a H- bridge power inverter.
In such a module, the grid voltage vAC is imposed to the output of the Current Controlled Series Regulator. It is given by:
V AC= VMcosωt
The voltage waveform is given on fig 5A. This maximum peak voltage VM for a grid voltage where Vrms is 220V is given by the relationship:
The Current Controlled Series Regulator (CCSR) has to deliver to the H bridge a variable current iOut able to be transferred to the grid under a sinus waveform having the same phase as the voltage vAC. Let us supposed that the MPP power is IkW1 therefore the rms
value Irms of the iAC current is lkW/220=4.54 A. It cor¬ responds a sinus current waveform with a peak value IM (half of the peak to peak value) such as:
The current xout to be delivered by the CCSR, as the H-Bidge is m charge to the transfer of power to the grid under a sinus waveform, corresponds to the absolute values of the grid current iAC that is:
iout = ABS/ 1 AC cos ωt / = 3. Hcos ωt
The waveform of the current iout is shown on fig 5B. The power PAC delivered to the grid is given on fig 5c. It corresponds to the relationship:
PAC = VMIM cos2 ωt = -^-^ (1 + 2 cosωt)
It is a sinus waveform around the averaged power that is the MPP power.
The variable delivered power PAC is available at the input of the Current Controlled Series Regulator which receives a constant power, the MPP power PMpp- The difference Pc between these both powers corresponds to the waveform given on fig 6, given by: Pc = P^p-PAC = P^P--^(l+2cosωt)
It is equivalent to a power ripple to be filtered at the input of the Current Controlled Series Regulator, as it is shown in figure 6.
The ripple shown in figure 6 may be filtered passively by a huge reactive filter composed by a capacitance C or an LC filter. It leads to a heavy and massive filter. It cannot be suppressed the voltage ripple v on the capacitance terminals. The worst case is given by:
C ^ VyMPP
A ripple of IV for an application where VW is around 400V and PMPP is IkW will require a capacitance C of several thousands of F.
The Current Controlled Series Regulator is necessary to generate the current iout as shown on fig 5B. Its output voltage vout is imposed by the grid. Trans- ferred by the H-Bridge this voltage is a positive half sinus waveform. This regulator can be buck or boost type such as the output current is controlled by a command v such as, if G is a constant and GMpp a parameter dependent on VW and vout:
The block diagram of this regulator, in the case of a buck power cell is given on fig 7. It is a classical current control buck where the sawtooth current wave- form i (t) of the switch QA is compared to an analogue command Gv using a Comparator. This current follows the relationship:
/(A=/ +VMPP-Vmt
When at time tc where this current reaches a maximum iM value such as:
/-> , • , V r MPP - v yout f lM = CjV = lm + L 1C
the output of the Comparator changes sign and the Logic circuit which has switched on QA according to a clock generator, switches off QA and switches on Q3. As:
V r MPP -v out ÷ ι~ι. , V MPP -v vout + out M j C T C
In a buck, with a sampling period T, the switch on time tc is given by:
τ tc _ - i T∑MP£. v out
Therefore
_ (~<v _ MPP Vout j, 'MPP
°ut L v oΛut The output current must have a half sinus positive waveform with a peak value IM dependent on IMPP in order that the same quantity of electricity is exchanged in the input of the regulator that is:
*M ~ 7^MPP
The command Gv(t) is realised by a microprocessor which receives inputs from :
-the grid voltage to generate a waveform
Gv (t) in phase with vAC -the current IMpp to the maximum amplitude of the Gv (t)
-the output current io for the feedback control of this parameter.
The voltage Gv (t) is the output voltage provided by a microprocessor which amplifies Ia difference between the current going to the inverter and the current coming from the S3R. It is a control command which defines the upper limit of the switching current enter- ing the inverter. And as it can be observed in figure 7 depending of the difference between Gv (t) and IM, the CCSR will work as a buck or as a boost type regulator, activitmg either QA or QB .
In this figure 7, it is also possible to observe the inverter H-Bridge which is composed of 4 switches Qi Q2 Q3 Qi The switches Q1 and Q3 are activated by the same driver as well as the switches Q2 and Q4 by another driver. Both drivers are synchronised by the grid voltage.
In order to avoid a power ripple at the input of the regulator and reduce the voltage ripple by a huge reactive filter, an active filter has to be inserted between the MPPC-S3R and the regulator. The block diagram of this process is shown on fig 2, wherein it can be observed that a bidirectional non dissipative regulator connected to an energy storage device has been mounted at the interface between the MPPC-S3R and the Con- trolled Current Series Regulator.
The bidirectional non dissipative regulator connected to the energy storage device, a capacitance or a battery, mounted at the interface between the S3R and the Current Controlled Series Regulator has the object- ive to derive to the energy storage device the excess of power and restore it when it is required by the inverter. The following relationship is imposed at the interface, if Pc is the power involved in the energy storage device : Pc = PMPP - PAC = PMPP -^-{\ + 2 cosωt)
On fig 8 is detailed the block diagram of the complete MPPC-S3R Inverter with the active filter. This filter is a bidirectional current controlled regulator. It operates as a buck to transfer power from the S3R to the capacitance C5 and as a boost to send power to the inverter. The switches of the regulator are QAε and QBε .The principle is the same as the Current Controlled Series Regulator. The saw tooth current 2s(t) flowing into switch QAS is sensed and compared to an analogue command Gv5 .This current is positive in the buck operation (power to the capacitance C5) and negative in the boost mode (power to the CCSR) . The switch is activated by a clock via the Logic circuit and the driver, and switched off when the comparator changes state that is:
The current m the inductance L3 is controlled by a feedback loop which compares it to a variable reference current via an Error Amplifier which generates the command Gv5
This variable reference is the result of a comparison of the MPP current IMPP with the inverter current I entering the Current Controlled Series Regulator via an Amplifier. In order to eliminates the sawtooth ripple, an LC filter is inserted between the S3R and the inverter.
The essential nature of this invention is not altered by variations in materials, form, size and ar- rangement of the component elements, described in a non- restrictive manner, sufficient for an expert to proceed to the reproduction of thereof.
Claims
1.- Device able to extract the maximum of energy from a solar array and to transfer it, into a grid cha- racterized in that it comprises:
- a Modular Non Dissipative Switching Regulator (MPPC-S3R) which delivers DC power at its maximum Power Point (MPP) , and it has n dedicated channels being every channel connected to the n branches of the solar array.
- an Inverter Module comprising a Current Controlled Non Dissipative Series Switching Regulator CCSR able to convert DC power supplied by the Modular Switching regulator into AC power, and a H- bridge Power Inverter
- a Bidirectional switching series regulator connected to an energy storage device is mounted at the interface between the MPPC-S3R and the Current Controlled Series Regulator (CCSR) .
2.- Device according to claim 1 characterized in that the Modular Non Dissipative Switching Regulator (MPPC-S3R) is composed of a microprocessor and means for generating a reference command
3.- Device according to claim 2 characterized in that every of the n channels the Modular Non Dissipative Switching Regulator (MPPC-S3R) is composed of a shunt power switch Q and a series power diode.
A.- Device according to claim 1 characterized in that the Current Controlled Non Dissipative Series Switching Regulator CCSR of the inverter module, com¬ prises a micropressor a comparator a clock, a logic cir- cuit and a driver, wherein the microprocessor generates
a control command Gv (t) which defines the upper limit of the switching current entering in the inverter and compared with IM/ the CCSR will work as a buck or as a boost type regulator, activating either of switches QA or QB the CCSR has.
5.- Device according to claim 1 characterized in that the H-Bridge of the Power Inverter is composed of 4 switches Qi Q∑ Q3 Q4 The switches Q1 and Q3 are activated by the same driver as well as the switches Q2 and Q4 by another driver. Both drivers are synchronised by the grid voltage
6.- Device according to claim 1 characterized in that the Bidirectional Switching Series Regulator comprises a micropressor a comparator a clock, a logic circuit and a driver, and the Storage device is a Capacitance .
1.- Process to extract maximum energy from a solar array with the device previously claimed which is comprised of:
- a Modular Non Dissipative Switching Regulator (MPPC-S3R) which delivers DC power at its ma- ximum Power Point (MPP) , and it has n channels being every channel connected to the n branches of the solar array.
- an Inverter Module comprising a Current Controlled Non Dissipative Series Switching Regu- lator CCSR able to convert DC power supplied by the Modular Switching regulator into AC power, and a H- bridge Power Inverter
- a Bidirectional switching series regulator connected to an energy storage device is moun- ted at the interface between the MPPC-S3R and the
Current Controlled Series Regulator (CCSR) .
And the processed comprises the following actions.
• the MPPC-S3R evaluates the energy performance of each branch of a solar array and it regulates the MPP voltage of the solar array (or the n solar panels) according to a reference command VRMPP generated by a microprocessor which computes the MPP of the solar array using the measurements of the in current coming from each solar panel, the solar array voltage v and the status of power switches Qn of every channel . • The CCSR (Current Controlled Series Regulator) of the inverter module converts the DC voltage at the output of the MPPC-S3R module into AC current and can work as a buck or boost type such as the current output is controlled by a command Gv (t)
• The Bidirectional switching series regulator operates as a buck to transfer power from the MPPC-S3R to a capacitance Cs and as a boost to send power to the inverter.
8.- Process to extract maximum energy from a solar array according to claim 7 characterized in that the command Gv (t) is realised by a microprocessor which receives inputs from :
-the grid voltage to generate a waveform Gv (t) in phase with vAC
-the current IMPP to the maximum amplitude of the Gv (t)
-the output current xo for the feedback control of this parameter
9.- Process to extract maximum energy from a solar array according to claim 7 characterized in that the The Bidirectional switching series regulator comprises two switches QAS and QBS wherein the saw tooth current is(t) flowing into switch QAS is sensed and compared to an analogue command Gv5 this current is posit- ive in the buck operation (power to the capacitance Cs) and negative in the boost mode (power to the CCSR) ; the switch is activated by a clock via the Logic circuit and the driver, and switched off when the comparator changes state
10.- Process to extract maximum energy from a solar array according to claim 7 characterized in that the storage device connected to the Bidirectional Switching Series Regulator is comprises by Capacitance Cs and an inductance Ls where the current m the inductance Ls is controlled by a feedback loop which com¬ pares it to a variable reference current via an Error Amplifier which generates the command Gv3
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP2009/003376 WO2010130273A1 (en) | 2009-05-12 | 2009-05-12 | Device to extract maximum power from a solar array and process to carry it out |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/EP2009/003376 WO2010130273A1 (en) | 2009-05-12 | 2009-05-12 | Device to extract maximum power from a solar array and process to carry it out |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2010130273A1 true WO2010130273A1 (en) | 2010-11-18 |
Family
ID=42236327
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/EP2009/003376 WO2010130273A1 (en) | 2009-05-12 | 2009-05-12 | Device to extract maximum power from a solar array and process to carry it out |
Country Status (1)
| Country | Link |
|---|---|
| WO (1) | WO2010130273A1 (en) |
Cited By (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20110140535A1 (en) * | 2009-12-16 | 2011-06-16 | Samsung Sdi Co., Ltd. | Power converting device for new renewable energy storage system |
| US20110175451A1 (en) * | 2010-01-18 | 2011-07-21 | Samsung Sdi Co., Ltd. | Power storage apparatus, method of operating the same, and power storage system |
| CN102324583A (en) * | 2011-09-01 | 2012-01-18 | 航天东方红卫星有限公司 | Lithium ion storage battery charging method based on sequential shunt switching regulation (S3R) |
| EP2606550A2 (en) * | 2010-08-18 | 2013-06-26 | Volterra Semiconductor Corporation | Switching circuits for extracting power from an electric power source and associated methods |
| EP2634909A1 (en) * | 2012-03-02 | 2013-09-04 | ABB Research Ltd. | Method for controlling a grid-connected boost-buck full-bridge current-source inverter cascade for photovoltaic applications and device |
| GB2500190A (en) * | 2012-03-12 | 2013-09-18 | Eltek As | Control of H-bridge inverter in continuous mode |
| CN106647920A (en) * | 2016-12-23 | 2017-05-10 | 山东航天电子技术研究所 | Satellite power controller |
| FR3050548A1 (en) * | 2016-04-22 | 2017-10-27 | Antoine Capel | MANAGEMENT OF A PHOTOVOLTAIC POWER SYSTEM BY A POWER CONDITIONING UNIT (PCU) CALCULATING THE MAXIMUM POWER POINT (MPPC) |
| CN110525696A (en) * | 2019-07-22 | 2019-12-03 | 中国空间技术研究院 | A kind of interannular pressure difference that reduces divides battle array and SADA matching optimization method |
| US11451052B2 (en) | 2018-05-04 | 2022-09-20 | Nextracker Llc | Systems and methods of DC power conversion and transmission for solar fields |
| US11460488B2 (en) | 2017-08-14 | 2022-10-04 | Koolbridge Solar, Inc. | AC electrical power measurements |
| US11509163B2 (en) | 2011-05-08 | 2022-11-22 | Koolbridge Solar, Inc. | Multi-level DC to AC inverter |
| US11513548B2 (en) | 2020-10-06 | 2022-11-29 | Samsung Electronics Co., Ltd. | Apparatus and method for tracking maximum power |
| US11901810B2 (en) | 2011-05-08 | 2024-02-13 | Koolbridge Solar, Inc. | Adaptive electrical power distribution panel |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19919766A1 (en) * | 1999-04-29 | 2000-11-02 | Sma Regelsysteme Gmbh | Inverter for a photovoltaic unit for use in a solar generator to maximize the power/performance output, the so-called maximum power point tracking |
-
2009
- 2009-05-12 WO PCT/EP2009/003376 patent/WO2010130273A1/en active Application Filing
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE19919766A1 (en) * | 1999-04-29 | 2000-11-02 | Sma Regelsysteme Gmbh | Inverter for a photovoltaic unit for use in a solar generator to maximize the power/performance output, the so-called maximum power point tracking |
Non-Patent Citations (9)
| Title |
|---|
| ALI KHAJEHODDIN S ET AL: "A Novel topology and control strategy for maximum power point trackers and multi-string grid-connected PV inverters", APPLIED POWER ELECTRONICS CONFERENCE AND EXPOSITION, 2008. APEC 2008. TWENTY-THIRD ANNUAL IEEE, IEEE, PISCATAWAY, NJ, USA, 24 February 2008 (2008-02-24), pages 173 - 178, XP031253244, ISBN: 978-1-4244-1873-2 * |
| ALONSO O ET AL: "Cascaded h-bridge multilevel converter for grid connected photovoltaic generators with independent maximum power point tracking of each solar array", PESC'03. 2003 IEEE 34TH. ANNUAL POWER ELECTRONICS SPECIALISTS CONFERENCE. CONFERENCE PROCEEDINGS. ACAPULCO, MEXICO, JUNE 15 - 19, 2003; [ANNUAL POWER ELECTRONICS SPECIALISTS CONFERENCE], NEW YORK, NY :; IEEE, US LNKD- DOI:10.1109/PESC.2003.1218146, vol. 2, 15 June 2003 (2003-06-15), pages 731 - 735, XP010648900, ISBN: 978-0-7803-7754-7 * |
| BANGYIN LIU ET AL: "Design considerations and topology selection for dc-module-based building integrated photovoltaic system", INDUSTRIAL ELECTRONICS AND APPLICATIONS, 2008. ICIEA 2008. 3RD IEEE CONFERENCE ON, IEEE, PISCATAWAY, NJ, USA, 3 June 2008 (2008-06-03), pages 1066 - 1070, XP031293888, ISBN: 978-1-4244-1717-9 * |
| EDELMOSER K H ET AL: "Bi-directional DC-to-DC converter for solar battery backup applications", POWER ELECTRONICS SPECIALISTS CONFERENCE, 2004. PESC 04. 2004 IEEE 35T H ANNUAL AACHEN, GERMANY 20-25 JUNE 2004, PISCATAWAY, NJ, USA,IEEE, US LNKD- DOI:10.1109/PESC.2004.1355437, vol. 3, 20 June 2004 (2004-06-20), pages 2070 - 2074, XP010739590, ISBN: 978-0-7803-8399-9 * |
| GULES R ET AL: "A Maximum Power Point Tracking System With Parallel Connection for PV Stand-Alone Applications", IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, IEEE SERVICE CENTER, PISCATAWAY, NJ, USA LNKD- DOI:10.1109/TIE.2008.924033, vol. 55, no. 7, 1 July 2008 (2008-07-01), pages 2674 - 2683, XP011226625, ISSN: 0278-0046 * |
| HUAN YANG ET AL: "A power conditioning system for a hybrid energy system with photovoltaic and sodium-sulfur battery", ELECTRICAL MACHINES AND SYSTEMS, 2007. ICEMS. INTERNATIONAL CONFERENCE ON, IEEE, PI, 1 October 2007 (2007-10-01), pages 244 - 247, XP031197240, ISBN: 978-89-86510-07-2 * |
| IMHOFF J ET AL: "DC-DC converters in a multi-string configuration for stand-alone photovoltaic systems", POWER ELECTRONICS SPECIALISTS CONFERENCE, 2008. PESC 2008. IEEE, IEEE, PISCATAWAY, NJ, USA, 15 June 2008 (2008-06-15), pages 2806 - 2812, XP031300387, ISBN: 978-1-4244-1667-7 * |
| JUNG-MIN KWON ET AL: "Grid-Connected Photovoltaic Multistring PCS With PV Current Variation Reduction Control", IEEE TRANSACTIONS ON INDUSTRIAL ELECTRONICS, IEEE SERVICE CENTER, PISCATAWAY, NJ, USA LNKD- DOI:10.1109/TIE.2008.2010293, vol. 56, no. 11, 2 December 2008 (2008-12-02) - 9 October 2009 (2009-10-09), pages 4381 - 4388, XP011266932, ISSN: 0278-0046 * |
| MEINHARDT M ET AL: "Multi-string-converter with reduced specific costs and enhanced functionality", SOLAR ENERGY, PERGAMON PRESS. OXFORD, GB LNKD- DOI:10.1016/S0038-092X(01)00067-6, vol. 69, 1 July 2001 (2001-07-01), pages 217 - 227, XP004303022, ISSN: 0038-092X * |
Cited By (28)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8482155B2 (en) * | 2009-12-16 | 2013-07-09 | Samsung Sdi Co., Ltd. | Power converting device for renewable energy storage system |
| US20110140535A1 (en) * | 2009-12-16 | 2011-06-16 | Samsung Sdi Co., Ltd. | Power converting device for new renewable energy storage system |
| US20110175451A1 (en) * | 2010-01-18 | 2011-07-21 | Samsung Sdi Co., Ltd. | Power storage apparatus, method of operating the same, and power storage system |
| US8575780B2 (en) * | 2010-01-18 | 2013-11-05 | Samsung Sdi, Co., Ltd. | Power storage apparatus, method of operating the same, and power storage system |
| US9577426B2 (en) | 2010-08-18 | 2017-02-21 | Volterra Semiconductor LLC | Switching circuits for extracting power from an electric power source and associated methods |
| US9698599B2 (en) | 2010-08-18 | 2017-07-04 | Volterra Semiconductor LLC | Switching circuits for extracting power from an electric power source and associated methods |
| EP2606550A2 (en) * | 2010-08-18 | 2013-06-26 | Volterra Semiconductor Corporation | Switching circuits for extracting power from an electric power source and associated methods |
| EP2606550A4 (en) * | 2010-08-18 | 2014-09-10 | Volterra Semiconductor Corp | Switching circuits for extracting power from an electric power source and associated methods |
| US8946937B2 (en) | 2010-08-18 | 2015-02-03 | Volterra Semiconductor Corporation | Switching circuits for extracting power from an electric power source and associated methods |
| US9035626B2 (en) | 2010-08-18 | 2015-05-19 | Volterra Semiconductor Corporation | Switching circuits for extracting power from an electric power source and associated methods |
| US9312769B2 (en) | 2010-08-18 | 2016-04-12 | Volterra Semiconductor LLC | Switching circuits for extracting power from an electric power source and associated methods |
| US9806523B2 (en) | 2010-08-18 | 2017-10-31 | Volterra Semiconductor LLC | Switching circuits for extracting power from an electric power source and associated methods |
| US11791711B2 (en) | 2011-05-08 | 2023-10-17 | Koolbridge Solar, Inc. | Safety shut-down system for a solar energy installation |
| US11509163B2 (en) | 2011-05-08 | 2022-11-22 | Koolbridge Solar, Inc. | Multi-level DC to AC inverter |
| US11901810B2 (en) | 2011-05-08 | 2024-02-13 | Koolbridge Solar, Inc. | Adaptive electrical power distribution panel |
| CN102324583A (en) * | 2011-09-01 | 2012-01-18 | 航天东方红卫星有限公司 | Lithium ion storage battery charging method based on sequential shunt switching regulation (S3R) |
| US8929108B2 (en) | 2012-03-02 | 2015-01-06 | Abb Research Ltd | Method and apparatus for controlling a grid-connected converter |
| EP2634909A1 (en) * | 2012-03-02 | 2013-09-04 | ABB Research Ltd. | Method for controlling a grid-connected boost-buck full-bridge current-source inverter cascade for photovoltaic applications and device |
| US9225236B2 (en) | 2012-03-12 | 2015-12-29 | Eltek As | Method for controlling an H-bridge inverter |
| GB2500190A (en) * | 2012-03-12 | 2013-09-18 | Eltek As | Control of H-bridge inverter in continuous mode |
| FR3050548A1 (en) * | 2016-04-22 | 2017-10-27 | Antoine Capel | MANAGEMENT OF A PHOTOVOLTAIC POWER SYSTEM BY A POWER CONDITIONING UNIT (PCU) CALCULATING THE MAXIMUM POWER POINT (MPPC) |
| CN106647920A (en) * | 2016-12-23 | 2017-05-10 | 山东航天电子技术研究所 | Satellite power controller |
| CN106647920B (en) * | 2016-12-23 | 2018-01-09 | 山东航天电子技术研究所 | A kind of satellite power supply controller |
| US11460488B2 (en) | 2017-08-14 | 2022-10-04 | Koolbridge Solar, Inc. | AC electrical power measurements |
| US11451052B2 (en) | 2018-05-04 | 2022-09-20 | Nextracker Llc | Systems and methods of DC power conversion and transmission for solar fields |
| CN110525696B (en) * | 2019-07-22 | 2021-06-11 | 中国空间技术研究院 | Array and SADA (simple adaptive array and adaptive differential architecture) matching optimization method for reducing pressure difference between rings |
| CN110525696A (en) * | 2019-07-22 | 2019-12-03 | 中国空间技术研究院 | A kind of interannular pressure difference that reduces divides battle array and SADA matching optimization method |
| US11513548B2 (en) | 2020-10-06 | 2022-11-29 | Samsung Electronics Co., Ltd. | Apparatus and method for tracking maximum power |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| WO2010130273A1 (en) | Device to extract maximum power from a solar array and process to carry it out | |
| US10050446B2 (en) | Device and method for global maximum power point tracking | |
| Armghan et al. | Design of integral terminal sliding mode controller for the hybrid AC/DC microgrids involving renewables and energy storage systems | |
| Ahmed et al. | Development of an efficient utility interactive combined wind/photovoltaic/fuel cell power system with MPPT and DC bus voltage regulation | |
| KR20210096656A (en) | Virtual Synchronous Generator Systems and Methods | |
| JP5929258B2 (en) | Power supply system and power supply device | |
| Fathabadi | Novel standalone hybrid solar/wind/fuel cell/battery power generation system | |
| KR20110098346A (en) | Energy storage system and controlling method of the same | |
| KR101830666B1 (en) | Power conversion apparatus | |
| Kabalci et al. | Hybrid microgrid testbed involving wind/solar/fuel cell plants: A desing and analysis testbed | |
| Thang et al. | Analysis and design of a single-phase Flyback microinverter on CCM operation | |
| Bastos et al. | An intelligent control system used to improve energy production from alternative sources with DC/DC integration | |
| CA2784963A1 (en) | Ac diversion mode controller | |
| Sangwongwanich et al. | Sensorless reserved power control strategy for two-stage grid-connected photovoltaic systems | |
| Jayalakshmi et al. | A new control method to mitigate power fluctuations for grid integrated PV/wind hybrid power system using ultracapacitors | |
| Solanki et al. | Power smoothing techniques to mitigate solar intermittency | |
| el Harry Mhamdi et al. | A power management strategy for hybrid photovoltaic diesel system with battery storage | |
| Dehbonei et al. | A combined voltage controlled and current controlled" dual converter" for a weak grid connected photovoltaic system with battery energy storage | |
| CN203103982U (en) | Maximum power tracking control system of two-stage grid-connected photovoltaic inverter | |
| Nouaiti et al. | Experimental Implementation of a Low-Cost Single Phase Five-Level Inverter for Autonomous PV System Applications Without Batteries. | |
| KR101484064B1 (en) | Power management device for new Renewable Energy | |
| Adhikari | Design of solar photovoltaic energy generation system for off-grid applications | |
| Verma et al. | Grid connected single phase rooftop PV system with limited reactive power supply | |
| Pozzebon et al. | A grid-connected multilevel converter for interfacing PV arrays and energy storage devices | |
| Jassim et al. | Dual Droop-Based Controllers for Hybrid Microgrid with Photovoltaic and Wind Turbine Distributed Generators |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| 121 | Ep: the epo has been informed by wipo that ep was designated in this application |
Ref document number: 09776606 Country of ref document: EP Kind code of ref document: A1 |
|
| NENP | Non-entry into the national phase |
Ref country code: DE |
|
| 122 | Ep: pct application non-entry in european phase |
Ref document number: 09776606 Country of ref document: EP Kind code of ref document: A1 |