CN102084584A - Method and system for providing maximum power point tracking in an energy generating system - Google Patents

Abstract

A method for providing a maximum power point tracking (MPPT) process for an energy generating device (202) is provided. The method includes coupling a local converter (204) to the energy generating device (202). A determination is made regarding whether the local converter (204) is operating at or below a maximum acceptable temperature. A determination is made regarding whether at least one current associated with the local converter (204) is acceptable. When the local converter (204) is determined to be operating at or below the maximum acceptable temperature and when the at least one current associated with the local converter (204) is determined to be acceptable, the MPPT process is enabled within the local converter (204).

Description

The method and system of maximum power point tracking is provided in energy production system

Technical field

The content that is disclosed is about energy production system haply.Clearer and more definite, disclosure is about in order to the method and system of maximum power point tracking to be provided in energy production system.

Background technology

For the energy source (from as coal or oil) that known non-regeneration, meeting are polluted, solar energy and wind-force provide energy source renewable and that can not pollute.Therefore, solar energy and wind-force have become the energy source that can be exchanged into electric energy that becomes more and more important.For solar energy, it is the device of electric energy that the photovoltaic panel that is arranged in array provides usually in order to conversion solar.Similarly array can be used for collecting wind-force or other natural energy source.

When operational light voltaic array, use the maximum power point tracking (MPPT) should be in which kind of voltage or this array of current practice, to produce maximum power output usually at specified temp and solar radiation automatically to judge.Although when array ideal conditions (that is, for each panel in the array identical radiation, temperature and electrical property feature are arranged) time, for whole array, it is quite simple to implement MPPT, but as do not match or the situation of partly crested under, then more complicated for the MPPT of whole array.In this case, because the multimodal power of unmatched array is to the relative optimum condition of voltage characteristic, the MPPT technology can not provide accurate result.Therefore, only there are some to operate ideally in this array panel.Because it is for the array that comprises number row's panels, the most inefficient panel can determine the electric current and the efficient of integral panels, like this then cause the violent decline of generation power.

Description of drawings

In order disclosure and feature thereof to be had more complete understanding, please refer to the following explanation that is attended by accompanying drawing, wherein;

Figure 1A is the embodiment according to disclosure, shows an energy production system, and it can utilize centralized local maximum power point tracking (MPPT) to integrate MPPT;

Figure 1B is the embodiment according to disclosure, shows an energy production system, and it can be central controlled;

Fig. 2 is the embodiment according to disclosure, shows the local transitions device of Figure 1A or Figure 1B;

Fig. 3 is the embodiment according to disclosure, the thin portion of the local transitions device of displayed map 2;

Fig. 4 A is the embodiment according to disclosure, shows in order to realize the method for MPPT in the local transitions device of Fig. 2;

Fig. 4 B is the embodiment according to disclosure, shows in order to realize the method for MPPT in the local transitions device of Fig. 2;

Fig. 5 is the embodiment according to disclosure, shows an energy production system, and it comprises a central array controller, and it can be this energy production system choice set Chinese style MPPT or distributed MPPT;

Fig. 6 is the embodiment according to disclosure, the array of the Fig. 5 under the situation of demonstration part crested;

Fig. 7 A-C is for showing that voltage corresponding to three photovoltaic panels of Fig. 6 is to power characteristic;

Fig. 8 is the embodiment according to disclosure, is shown as energy production system choice set Chinese style MPPT or the method for distributed MPPT of Fig. 5;

Fig. 9 is the embodiment according to disclosure, shows startup and closes the system of the local control of the local transitions device in the energy production system;

Figure 10 is the embodiment according to disclosure, the example that display unit voltage changed along with the time;

Figure 11 is the embodiment according to disclosure, the starter of displayed map 9; And

Figure 12 is the embodiment according to disclosure, shows in order to start or to close the method for the local transitions device of Fig. 9.

Embodiment

In this part patent document, the various embodiment that Fig. 1 to 12 of the following stated and being used to describes principle of the present invention only are used for explanation and should not be construed as and limit the scope of the invention.Knowing this skill person ought be as can be known, and principle of the present invention can be applied to the device or the system of the suitable configurations of any kind.

Figure 1A is the embodiment according to disclosure, shows an energy production system 10, and it can utilize centralized local maximum power point tracking (MPPT) to integrate MPPT.Energy production system 10 comprises most energy producing units (EGD) 12, respectively is coupled to corresponding local transitions device 14, and EGD 12 and corresponding local transitions device 14 merging form energy and produce array 16.Described photovoltaic system 10 also comprises the DC-AC transducer 22 that is coupled to local transitions device 14, and it can be in order to from local transitions device 14 received currents and voltage.

For a specific embodiment, as described in disclosure, energy production system 10 can comprise the photovoltaic system, and energy producing unit 12 can comprise photovoltaic (PV) panel.Yet, should be appreciated that energy production system 10 can comprise any other energy production system of suitable species, for example wind turbine system, fuel cell system etc.For these embodiment, energy producing unit 12 can comprise wind turbine, fuel cell etc.And energy production system 10 can be grounding system or floating system.

PV panel 12 in the array 16 is arranged on the string 24, and for described embodiment, array 16 comprises two strings 24, and each is gone here and there and 24 comprises three panels 12.Yet, should be appreciated that array 16 can comprise the string 24 of any suitable number, and respectively go here and there 24 panels 12 that can comprise any suitable number.And for described embodiment, each panel 12 of going here and there in 24 is set to be connected in series.Therefore, the output voltage of each local transitions device 14 still is comparable to its input voltage, and supplies with the input port of high voltage to DC-AC transducer 22, and for some embodiment, it is operable in input voltage is that 150V is between the 500V.Therefore, need not produce and realize that high efficiency reaches the ability of local transitions device 14 cheaply based on the transducer (for example user of institute in parallel connection structure string) of transformer.

Each PV panel 12 can be an electric energy with solar energy converting.Each local transitions device 14 is to be coupled to corresponding panel 12, and can refigure the voltage that causes of panel 12 to the input relation of electric current, the electric energy that the panel 12 of array 16 is produced can be load (not showing among Figure 1A) and utilizes.DC-AC transducer 22 is to be coupled to array 16, and the load direct current (DC) that local transitions device 14 produces can be converted to interchange (AC), and load can be coupled to DC-AC transducer 22.DC-AC transducer 22 comprises central MPPT control block 32, and it can provide centralized MPPT by the MPP of calibration array 16.

MPPT judges voltage or the electric current that array 16 or panel 12 should be operated automatically, so that specified temp and solar radiation are produced maximum power output.Although when array ideal conditions (that is, for each panel in the array identical radiation, temperature and electrical property feature are arranged) time, for whole array, it is quite simple to implement centralized MPPT, but as do not match or the situation of partly crested under, then more complicated for the MPPT of whole array.Therefore, only there are some to operate ideally in this array panel, cause power to produce violent decline.

10 pairs of total systems of energy production system 10 are provided with the system's Control Circulation that is subjected to 32 controls of central MPPT control block, and each panel 12 is provided with the local Control Circulation of being controlled by the local transitions device 14 of correspondence.The frequency of operation of these circulations is separated one section preset distance each other at least, avoiding system oscillation, and avoids panel 12 to leave its MPP operation.For an embodiment, system's Control Circulation is a closed loop system, and it comprises array 16, central MPPT control block 32, DC-AC transducer 22.In addition, each local Control Circulation is a closed loop system, and it comprises a panel 12 and corresponding local transitions device 14.

For some embodiment, stabilization time of local Control Circulation that each local transitions device 14 is designed so that transducer 14 than the time constant of system's Control Circulation for fast.In a specific embodiment, fast five times at least of stabilization times of each local Control Circulation than the time constant of system Control Circulation.Therefore, in stable state, the array 16 that panel 12 is formed can be used as the power supply of DC-AC transducer 22, the summation of the maximum power that its quantity of power can be used for each panel 12.Simultaneously, central MPPT control block 32 can be implemented regular optimized algorithm, and is last, and central MPPT control block 32 can be pressed crosstalk the value of the usefulness that is set at maximization local transitions device 14.

In this mode, can avoid the system oscillation that causes by the dynamic response between system's Control Circulation and the local Control Circulation.In addition, panel 12 generally can be in its MPP operation.Again, can between system and local circulation, synchronize them, press the infringement that may cause to avoid the unrestricted crosstalk that increases.At last, can avoid isolated DC-AC transducer 22, it can make DC-AC transducer 22 stop to absorb energy, and causes uncontrollable input voltage to grow up.

Figure 1B is the embodiment according to disclosure, and demonstration can be the energy production system 100 of centralized control.Energy production system 100 comprises most energy producing units (EGD) 102, and it respectively is coupled to corresponding local transitions device 104, and energy producing unit 102 and local transitions device 104 form energy together and produce array 106.For a specific embodiment, as described in disclosure, energy production system 100 can comprise the photovoltaic system, and energy producing unit 102 comprises photovoltaic (PV) panel.Yet, should be appreciated that energy production system 100 can comprise the energy production system of any other suitable species, for example wind turbine system, fuel cell system etc.For these embodiment, energy producing unit 102 can comprise wind turbine, fuel cell etc.And energy production system 100 can be grounding system or floating system.

Described photovoltaic system 100 comprises central array controller 110, and also comprises DC-AC transducer 112, or to be used for system 100 be other the suitable load that is operating as the situation of parallel connection type system.Yet, should be appreciated that system 100 can be by coupling array 106 to battery charger or other suitable energy accumulating device but not DC-AC transducer 112, and be operating as the self system.

PV panel 102 in the array 106 is to be arranged in the string 114.For described embodiment, array 106 comprises two strings 114, and each string 114 comprises three panels 102.Yet, should be appreciated that array 106 can comprise the string 114 of any suitable number, and each string 114 can comprise the panel 102 of any suitable number.Also for described embodiment, the panel 102 in each string 114 is for being connected in series.Therefore, when supplying with high voltage to the input port of DC-AC transducer 112, the output voltage of each local transitions device 104 is still near its input voltage.And for some embodiment, the input voltage of DC-AC transducer 112 operations is between the 500V between 150V.Therefore, do not need to be used for structure in parallel string with the transducer of transformer in the basis, like this then cause the high-effect ability of local transitions device 104 cheaply that reaches that realizes.

Each PV panel 102 can be an electric energy with solar energy converting.Each local transitions device 104 is to be coupled to corresponding panel 102, and can refigure panel 102 input voltage supplied to the input relation of electric current, the electric energy that the panel 102 of array 106 is produced can be load (showing among Figure 1B) and utilizes.DC-AC transducer 112 is coupled to array 106, and the load direct current (DC) that local transitions device 104 produces can be converted to interchange (AC), and load can be coupled to DC-AC transducer 112.

Ceiling capacity point tracking (MPPT) is judged voltage or the electric current that panel 102 should be operated automatically, so that specified temp and solar radiation are produced maximum power output.Although when array 106 when ideal conditions (that is, identical radiation, temperature and electrical property feature are arranged) for each panel 102 in the array 106, for whole array 106, it is quite simple to implement centralized MPPT.Yet, when for example have do not match or the situation of partly crested under, more complicated for the MPPT of whole array 106.In this case, because the multimodal power of unmatched array 106 is to the relative optimum condition of voltage characteristic, the MPPT technology can not provide accurate result.Therefore, only there are some panels 102 to operate ideally in this array 106, make the rapid decline of produce power.Therefore, for head it off, each local transitions device 104 can provide local MPPT to its corresponding panel 102.In this mode, and though desirable or do not match or the situation of crested under, each panel 102 all is operable in its own ceiling capacity point (MPP).For the embodiment that energy producing unit 102 wherein comprises wind turbine, MPPT can be used for adjusting the blade pitgh of wind turbine.Also should be appreciated that MPPT can be used for the system 100 that optimization comprises the energy producing unit 102 of other kind.

Central authorities' array controller 110 is coupled to array 106, and can see through wired connection (for example series connection or parallel bus) or wireless connections and array 106 communications.Central authorities' array controller 110 can comprise diagnostic module 120 and/or control module 125.Diagnostic module 120 energy monitor optical voltaic systems 100, and control module 125 can be controlled photovoltaic system 100.

Diagnostic module 120 can receive the device data that are used for the local transitions device data of local transitions device 104 and are used for local transitions device 104 corresponding panel 102 by each local transitions device 104 from array 106.The output voltage of " device data " as used herein expression panel 102, output current, temperature, radiation, power output etc.Similarly, " local transitions device data " expression local transitions device output voltage, local transitions device output current, local transitions device power output etc.

Diagnostic module 120 also can produce report in system 100, and provides report to give the operator.For example, diagnostic module 120 can display unit data and local transitions device data some of them or is all given the operator and check.In addition, diagnostic module 120 can generator data and local transitions device data some of them or is all given control module 125.Diagnostic module 120 also can be analyzed data in any suitable manner, and provides analysis result to give operator and/or control module 125.For example, diagnostic module 120 can be according to any suitable time limit, for example per hour, every day, jede Woche or every month, judges the statistics of each panel 102.

Diagnostic module 120 also can provide error monitoring to array 106.According to the data that received from local transitions device 104, but diagnostic module 120 identifications one or more have the panel 102 of flaw, for example Shi Bai panel 102, the panel 102 that lost efficacy, the panel 102 of crested, dirty panel 102 etc.When changing, repair or during cleaner panel 102 defective, diagnostic module 120 also can the notifying operation person.

Control module 125 can control signal to one or more local transitions device 104 and control array 106 practically by transmission.For example, control module 125 can transmit to detour and control signal to the specific portion transducer 104 that corresponding panel 102 lost efficacy.The control signal that detours impels local transitions device 104 to walk around panel 102, removes panel 102 from array 106 effectively and can not influence the operation of other panel 102 (as the panel 102 that is bypassed) in identical string 114.

In addition, control module 125 can transmit and control signal to one or more local transitions device 104, and its guiding local transitions device is adjusted its output voltage or electric current.For some embodiment, the MPPT function of local transitions device 104 can be moved to central array controller 110.For these embodiment, control module 125 is the MPP of each panel 102 of adjustable also, and transmits the conversion proportion order to each local transitions device 104 according to calibration, so that each panel 102 operates in its own MPP, judges as control module 125.

Control module 125 also can receive instruction and enabled instruction from the operator.For example, the bootable control module of operator 125 systems 100 are parallel connection type or self, and control module 125 can be by system 100 being made as parallel connection or independent this system 100 the operation response person.

Therefore, by utilizing central array controller 110, photovoltaic system 100 is that the basis can provide better utilization with the panel.And system 100 be by can mixing separate sources, and increases elasticity.Central authorities' array controller 110 also provides preferable protection and data collection to whole system 100.

Fig. 2 is the embodiment according to disclosure, shows local transitions device 204.Local transitions device 204 can represent among Figure 1A local transitions device 14 one of them, or the local transitions device among expression Figure 1B 104 one of them, yet, should be appreciated that, local transitions device 204 can be located in the energy production system in the scope that does not break away from disclosure in any suitable manner.In addition, although the those shown is coupled to the energy producing unit 202 that is called the PV panel, should be appreciated that local transitions device 204 can be coupled to the single battery of PV panel or the panel sub-portfolio of photovoltaic array, or be coupled to another energy producing unit 202, for example wind turbine, fuel cell etc.

Local transitions device 204 comprises power stage 206 and local control 208, the communication interface 212 that it more comprises MPPT module 210 and selects for use.Power stage 206 can comprise the DC-DC transducer, and it can receive panel voltages and electric current as input from PV panel 202, and the voltage of refigure input is to current relationship, to produce output voltage and electric current.

The communication interface 212 of local control 208 can provide the communication channel between local transitions device 204 and the central array controller (for example central array controller 110 among Figure 1B).Yet, not for the embodiment of central array controller communication, can omit communication interface 212 for local transitions device 204.

MPPT module 210 can receive panel voltages and electric current as input from panel 202, and if employed algorithm has needs, can be from power stage 206 reception output voltage and electric currents.According to these inputs, MPPT module 210 can provide signal, with power controlling level 206.In this mode, the MPPT module 210 of local control 208 can provide MPPT for PV panel 202.

By MPPT is provided, MPPT module 210 with corresponding panel 202 remain in fixing in fact operating point (that is, corresponding to the fixed voltage V of the maximum power point of panel 202 _PanAnd electric current I _Pan).Therefore, for given fixedly solar radiation, in stable state, if local transitions device 204 is corresponding to the relative or absolute maximum power point of panel 202, then the input power of local transitions device 204 be fix (that is, P _Pan=V _PanI _Pan).In addition, local transitions device 204 has high relatively usefulness, therefore, power output no better than input power (that is, P _Out=P _Pan).

Fig. 3 is the embodiment according to disclosure, shows the thin portion of local transitions device 204.For this embodiment, power stage 206 is embodied as single inductance, four switch synchronization lifting switch regulators, and MPPT module 210 comprises power stage adjuster 302, MPPT control block 304, reaches two AD converters (ADC) 306 and 308.

ADC 306 can convergent-divergent and quantization simulated panel voltage V _PanAnd simulated panel electric current I _Pan, to produce digitizing tablet voltage and digitizing tablet electric current respectively.Should be appreciated that, although described be panel voltage and panel currents, for any suitable energy producing unit 202 (for example wind turbine, fuel cell etc.), V _PanCan be described as output device voltage and I _PanCan be described as the output device electric current.The ADC 306 that is coupled to MPPT control block 304 and communication interface 212 also can provide digitizing tablet voltage and electric current to MPPT control block 304 and communication interface 212.Similarly, ADC 308 can convergent-divergent and quantization analog output voltage and analog output current, to produce digital output voltage and digital output current respectively.The ADC 308 that also is coupled to MMPT control block 304 and communication interface 212 can provide digital output voltage and current signal to MPPT control block 304 and communication interface 212.Communication interface 212 can provide digital output voltage that digitizing tablet voltage that ADC 306 produced and current signal and ADC 308 produced and current signal to central array controller.

The MPPT control block 304 that is coupled to power stage adjuster 302 can receive digitizing tablet voltage and electric current from ADC 306, and receives digital output voltage and electric current from ADC 308.According to these digital signals wherein at least some.MPPT control block 304 can produce the conversion proportion order that is used for power stage adjuster 302.The conversion proportion order comprises the conversion proportion that is used for power stage adjuster 302, to use when the operand power level 206.Can produce for the embodiment of conversion command according to digitizing tablet voltage and electric current (but not according to digital output voltage and electric current) for MPPT control block 304, ADC 308 only provides digital output voltage and electric current to communication interface 212, and can not control block 304 to MPPT.

For some embodiment, power stage adjuster 302 comprises lifting mode control logic and digital pulse width adjuster.This power stage adjuster 302 can produce pulse width modulation (PWM) signal by the conversion proportion that is provided according to MPPT control block 304, and making power stage 206 operate in different mode, MPPT control block 304 adjustables are used for the conversion proportion of the pwm signal of power stage 206.

Power stage adjuster 302 is coupled to power stage 206, and can be by using a work period and a pattern to come operand power level 206, and controlling the conversion proportion operand power level 206 that block 304 is produced according to MPPT, work period and this pattern system are judged according to conversion proportion.For the embodiment that power stage 206 is embodied as the lifting transducer, the possible pattern of power stage 206 comprises degraded mode, upgrade mode, lifting pattern, bypass mode and stop mode.

For this embodiment, when conversion proportion CR dropped in the range, power stage adjuster 302 can make power stage 206 operate in the lifting pattern; As conversion proportion CR during less than range, power stage adjuster 302 can make power stage 206 operate in degraded mode; As conversion proportion CR during greater than range, power stage adjuster 302 can make power stage 206 operate in upgrade mode.Range comprises and equals 1 value in fact.For example, for a specific embodiment, range comprises 0.95 to 1.05.When power stage 206 is degraded mode, if CR is less than maximum degradation conversion proportion CR _{Buck, max}, power stage adjuster 302 can be with the whole power stage 206 of degradation constructor.Similarly, if CR greater than minimum upgrade conversion ratio CR _{Boost, min}, power stage adjuster 302 can make power stage 206 operate in the upgrading structure.

At last, when conversion proportion greater than CR _{Buck, max}And less than CR _{Boost, min}The time, power stage adjuster 302 is operand power level 206 in degradation formation and upgrading formation alternately.In this case, power stage adjuster 302 can be implemented TCM, replaces between the formation to constitute and to upgrade at degradation.Therefore, when conversion proportion more near CR _{Buck, max}The time, power stage adjuster 302 operand power level 206 in degradation constitutes is frequent than operand power level 206 in upgrading constitutes.Similarly, when conversion proportion more near CR _{Boost, min}The time, power stage adjuster 302 operand power level 206 in upgrading constitutes is frequent than operand power level 206 in degradation constitutes.As the close CR of conversion proportion _{Buck, max}And CR _{Boost, min}Between intermediate point the time, power stage adjuster 302 operand power level 206 in degradation constitutes is equally matched with the frequent degree of operand power level 206 in upgrading constitutes.For example, when power stage 206 is during in the lifting pattern, power stage adjuster 302 blocked operation power stage 206 equably is that degradation constitutes and upgrading constitutes.

For described embodiment, power stage 206 comprises four switch 310a-d, and inductance L and capacitor C.For some embodiment, switch 310 can comprise N-channel power MOSFET.For a specific embodiment, these transistors can comprise the gallium nitride devices on the silicon.Yet, should be appreciated that do not breaking away within the disclosure scope, switch 310 can be other mode that is fit to and realizes.In addition, power stage 206 can comprise one or more driver (not showing among Fig. 3), with driving switch 310 (for example transistorized gate).For example, for a specific embodiment, first driver can be coupled between power stage adjuster 302 and transistor 310a and the 310b, gate with driving transistors 310a and 310b, second driver can be coupled between power stage adjuster 302 and transistor 310c and the 310d, with the gate of driving transistors 310c and 310d.For this embodiment, the pwm signal that power stage adjuster 302 is produced is supplied to driver, according to these signals, drives the gate of its other transistor 310 respectively.

For described embodiment, in operand power level 206, power stage adjuster 302 can produce digit pulse, with the switch 310 of power controlling level 206.For following embodiment, switch comprises transistor.For degradation constituted, power stage adjuster 302 cut out transistor 310c and turn-on transistor 310d.Then, transistor 310a and transistor 310b are alternately opened and close in pulse, make power stage 206 be operating as the degradation adjuster.For this embodiment, the work period of transistor 310a equals work period D, and it is contained in the conversion proportion order that MPPT control block 304 produced.For upgrade mode, power stage adjuster 302 turn-on transistor 310a and close transistor 310b.Transistor 310c and transistor 310d are alternately opened and close in pulse, so that power stage 206 is operating as the upgrading adjuster.For this embodiment, the work period of transistor 310 equals 1-D.

For the lifting pattern, power stage adjuster 302 is implemented TCM between degradation and upgrading formation, as above-mentioned.Power stage adjuster 302 produces and is used for the right control signal of degradation switch of transistor 310a and 310b, and is used for the right control signal of upgrading switch of transistor 310c and 310d.The work period of transistor 310a is fixed in corresponding CR _{Buck, max}Work period, the work period of transistor 310c is fixed in corresponding CR _{Boost, min}Work period.Constitute and upgrading constitutes ratio between the operation for to be linear scale with D through the degradation during one period fixed time.

When output voltage during near panel voltage, power stage 206 is to operate in the lifting pattern.In this case, for described embodiment, the stress that inductive current ripple and voltage switching cause is much smaller than SEPIC and known lifting transducer.And compared to known lifting transducer, described power stage 206 can reach higher usefulness.

For some embodiment, will together not be described in detail the person with Fig. 4 A as following, MPPT control block 304 can operate in following four patterns one of them: park mode, tracking pattern, maintenance pattern, and bypass mode.When panel voltage was less than predetermined elementary limit voltage, MPPT control block 304 was operable in the park mode.In park mode, MPPT control block 304 is closed transistor 310a-d.For example, for some embodiment, when MPPT control block was park mode, MPPT control block 304 can produce the conversion proportion order, and it impels power stage adjuster 302 to close transistor 310a-d.Therefore, power stage 206 ties up to stop mode, and panel 202 is bypassed, and is like this then can avoid removing panel 202 in the photovoltaic system that uses panel 202 effectively.

When panel voltage is elevated to when being higher than elementary limit voltage, MPPT control block 304 operates in the tracking pattern.In this pattern, MPPT control block 304 counter plates 202 are implemented maximum power point tracking, to judge the best transition ratio of power stage adjuster 302.And in this pattern, power stage adjuster 302 can depend on the conversion proportion order of present generation, and power stage 206 is placed degraded mode, upgrade mode or lifting pattern.

In addition, for some embodiment, MPPT control block 304 also can comprise and stops buffer, it can be revised by operator or any suitable control program (for example being located at the control program in the central array controller) of system, is stop mode to force MPPT control block 304 to keep power stage 206.For this embodiment, unless (i) panel voltage exceeds elementary limit voltage, and (ii) stop buffer and represent that MPPT control block 304 can shift out stop mode with power stage 206, otherwise MPPT control block 304 can not begin to operate in the tracking pattern.

When MPPT control block 304 was found out the best transition ratio, MPPT control block 304 can operate in the maintenance pattern time of one period scheduled period.In this pattern, MPPT control block 304 can continue to be provided at the identical conversion proportion that is judged as the best transition ratio in the tracking pattern and give power stage adjuster 302.And in this pattern, as in the tracking pattern, power stage 206 depends on the best transition ratio that the conversion proportion order is provided, and is in degraded mode, upgrade mode or the lifting pattern.After the process time of scheduled period, MPPT control block 304 can revert to the tracking pattern, can not change to guarantee best conversion proportion, or if the condition changing of panel 102 can be found out new best transition ratio.

As following more detailed explanation together with Fig. 5-8, each panel in the photovoltaic array (for example panel 202) is evenly illuminated, and when not matching between the panel 202, central array controller can be provided with MPPT control block 304 and be bypass mode with power stage 206.In bypass mode, for some embodiment, transistor 310a and 310d are for opening, and transistor 310b and 310c are for closing, so that panel voltage equals output voltage.For other embodiment, power stage 206 can comprise the switch of selecting for use 312, and power stage 206 can couple the input port to output port, so that output voltage equals panel voltage.In this mode, when not needing local MPPT, can remove local transitions device 204 from system in fact, by this by the loss that reduces relevant local transitions device 204, and maximization usefulness, and increase the life-span.

Therefore, as mentioned above, MPPT control block 304 can operate in the park mode, and power stage 206 is placed the stop mode of walking around panel 202.MPPT control block 304 also can operate in tracking pattern or maintenance pattern.No matter in which kind of pattern, MPPT control block 304 can place power stage 206 degraded mode, upgrade mode, reach one of them pattern of lifting pattern.At last, MPPT control block 304 can operate in the bypass mode, and power stage 206 is placed bypass mode, in bypass mode, can walk around local transitions device 204, allows that panel 202 directly is coupled to other panel 202 in the array.

By operating local transitions device 204 in this way, the crosstalk stream that comprises the panel string of panel 202 has nothing to do with other panel currents.Otherwise, be to set crosstalk stream by crosstalk pressure and total string power.In addition, there is not the panel 202 of crested can continue to operate in the peak power point, the condition of the part crested of other panel in need not considering to go here and there.

For a replaceability embodiment, when MPPT control block 304 was found out the best transition ratio, when best transition ratio during corresponding to the lifting pattern of power stage 206, but 304 inoperation of MPPT control block were in the maintenance pattern but operate in the bypass mode.In the lifting pattern, output voltage is near panel voltage.Therefore, panel 202 can operate near its maximum power point by walking around local transitions device 204, so then increases usefulness.Embodiment as the aforementioned, whether MPPT control block 304 reverts to the tracking pattern from bypass mode termly, fall within the lifting model domain with checking best transition ratio.

For some embodiment, MPPT control block 304 can be adjusted the conversion proportion that is used for power stage adjuster 302 gradually, and improper stepwise changes, with the stress of avoiding adding all transistors in power stage 206, inductance, reaching electric capacity.For some embodiment, MPPT control block 304 can be realized different MPPT technology, with adjustment panel voltage or conductivity, but not adjusts conversion proportion.In addition, MPPT control block 304 can be adjusted reference voltage, but not adjusts conversion proportion, to be used for dynamic input voltage regulation.

In addition, the stop mode of MPPT control block 304 energy activation power stages 206 and the quick relatively and level and smooth turnover between other pattern.MPPT control block 304 can comprise non-voltile memory, and it can store last maximum power dotted state, for example conversion proportion etc.For this embodiment, when MPPT control block 304 was transformed into park mode, maximum power dotted state system was stored in this non-voltile memory.When MPPT control block 304 revert to the tracking pattern thereafter, stored maximum power dotted state can be used as initial maximum power dotted state.In this mode, for power stage 206, stop and other pattern between change-over time can obviously reduce.

For some embodiment, MPPT control block 304 also can provide overpower and/or overvoltage protection to local transducer 204.Because signal V _PanAnd I _PanTo being fed forward MPPT control block 304, MPPT control square 304 is attempted the acquisition maximum power via ADC 306.If power stage 206 outputs have open-circuit, then the output voltage of local transitions device 204 reaches maximum.Therefore, for overpower protection, the output current of local transitions device 204 can be used as the signal of opening and closing MPPT control block 304.For this embodiment, too low if output current drops to, then can control block 304 and set conversion proportion, so that panel voltage output voltage no better than by MPPT.

For overvoltage protection, MPPT control block 304 can have maximum conversion proportion to the conversion proportion order, and MPPT control block 304 can not surpass this maximum conversion proportion.Therefore, if conversion proportion continues to be higher than maximum conversion proportion, then MPPT control block 304 is limited to maximum with conversion proportion.Like this then can guarantee that output voltage can not be increased to and surpass corresponding maximum.The value of maximum conversion proportion can be fixed or adaptive.For example, can calculate output voltage by induction panel voltage and according to the conversion proportion of power stage 206, and reach adaptive conversion proportion restriction corresponding to time sequencing value of conversion proportion.

In addition, for described embodiment, power stage 206 comprises the single-way switch of selecting for use 314.When power stage 206 is stop mode, comprise the switch of selecting for use 314 and be bypassed to allow panel 202, remove panel 202 from array whereby, and allow that other panel 202 continues operation.For certain embodiments, single-way switch 314 can comprise diode.Yet, should be appreciated that within the scope that does not break away from disclosure, single-way switch 314 can comprise the single-way switch of any other adequate types.

Fig. 4 A is the embodiment according to disclosure, is presented at the method 400 that realizes MPPT in the local transitions device 204.The embodiment of method 400 only is an illustrative.Can be within the scope that does not break away from disclosure, other embodiment of implementation method 400.

Method 400 is with MPPT controlled area block operations (step 401) to start with in park mode.For example, MPPT control block can produce the conversion proportion order, closes transistor 310a-d or power stage 206 to impel power stage adjuster 302, whereby power stage 206 is placed stop mode, and walks around panel 202.

When in park mode, MPPT control block 304 monitoring panel voltage V _Pan, and compare panel voltage and elementary limit voltage V _Th(step 402).For example, ADC 306 can be a digital signal with panel voltage self simulation conversion of signals, and digital signal is provided to MPPT control block 304, and it stores elementary limit voltage, to make comparisons with digitizing tablet voltage.

As long as panel voltage remains under the elementary limit voltage (step 402), MPPT control block 304 with regard to ongoing operation in park mode.In addition, as above-mentioned, when stopping buffer and represent that power stage 206 remains stop mode, MPPT control block 304 remains in the park mode.Yet, in case panel voltage exceeds elementary limit voltage (step 402), the conversion proportion order that MPPT control block 304 produces in order to operand power level 206, the conversion proportion order comprises initial conversion proportion (step 403).For example, for an embodiment, MPPT control block 304 with conversion proportion 1 to start with.Perhaps, MPPT control block 304 can be stored in the best transition ratio that last tracking pattern is judged.For this embodiment, MPPT control block 304 can be initialized as conversion proportion identical with the previous best transition ratio of judging.And the conversion proportion order that MPPT control block 304 is produced is supplied to power stage adjuster 302, and it uses initial conversion ratio operand power level 206.

At this moment, MPPT control block 304 monitoring panel electric current I _PanAnd output current I _Out, and compare panel currents and output current and threshold current I _Th(step 404).For example, ADC 306 can be a digital signal with panel currents self simulation conversion of signals, and the digitizing tablet electric current is supplied to MPPT control block 304, ADC 308 can be a digital signal with output current self simulation conversion of signals, and the supply numeral outputs current to MPPT control block 304, and it stores the threshold current in order to make comparisons with digitizing tablet electric current and digital output current.As long as electric current I _PanAnd I _OutWherein at least one is still kept and is lower than threshold current (step 404), and MPPT control block 304 will continue monitor current position standard.Yet in case these electric currents all exceed threshold current (step 404), MPPT control block 304 begins to operate in the tracking pattern, and it comprises initializing set tracking variable T is 1, and initialization one counter (step 406).

Although be not shown in the method 400 of Fig. 4 A, should be appreciated that in the time of in the tracking pattern, MPPT control block 304 can continue to monitor panel voltage, and compares panel voltage and the secondary limit voltage that is less than elementary limit voltage.If panel voltage reduces to and is lower than secondary limit voltage, then MPPT control block 304 reverts to park mode.Be less than the secondary limit voltage of elementary limit voltage by use, 304 pairs of noise immunity of MPPT control block so then can avoid MPPT control block 304 to switch between dormancy and the tracking pattern through being everlasting.

After setting the value and count initialized device of following the trail of variable, MPPT control block 304 calculates the initial power (step 408) that is used for panel 202.For example, ADC 306 can provide digitizing tablet electric current and panel voltage signal (I _PanAnd V _Pan) to MPPT control block 304, thereafter, MPPT control block 304 is with these signal multiplications, with decision maker (or panel) power (I _PanV _Pan) initial value.

After calculating initial power, MPPT control block 304 is revised conversion proportion with first direction, and produces the conversion proportion order (step 410) that comprises the conversion proportion of revising.For example, for some embodiment, MPPT control block 304 can increase conversion proportion.For other embodiment, MPPT control block 304 can reduce conversion proportion.After making system stability after a while, MPPT control block 304 calculates the current power (step 412) that is used for panel 202.For example, ADC 306 can provide digitizing tablet electric current and panel voltage signal to MPPT control block 304, and thereafter, MPPT control block 304 is with these signal multiplications, to judge the present value of panel power.

Then, power that MPPT control block 304 calculates relatively now and the previous power that calculates, it is an initial power (step 414).If at present power is greater than previous power (step 414), then MPPT control block 304 to be revising conversion proportion with the equidirectional of previous modification, and produces the conversion proportion order of upgrading (step 416).For some embodiment, increase with equivalent and to revise conversion proportion higher or lower.For other embodiment, conversion proportion can be revised highlyer with linear or non-linear increment or be lower, responds with optimization system.For example, for some system, if conversion proportion and optimum value gap are very big, then along with more close optimum value, the preferably uses bigger increment earlier, and then uses small incremental.

MPPT control block 304 also judges that following the trail of variable T equals 1, and expression was because conversion proportion changed before formerly calculating, and conversion proportion changes (step 418) with the direction identical with previous calculating.Therefore, when T equaled 1, panel power increased with the previous change of equidirectional along with conversion proportion.In this case, give system make a period of time its stable after, MPPT control block 304 calculates the present power (step 412) of panel 202 once more, and more present power and previous power (step 414).Yet, if MPPT control block 304 judges that T is not equal to 1, expression was because conversion proportion changed before formerly calculating, and conversion proportion changes (step 418) with the direction opposite with previous calculating, then MPPT control block 304 setting T are 1, and increase counter (step 420).

Then, MPPT control block 304 judges whether counter exceeds counter threshold value C _Th(step 422).If the value of counter does not exceed counter threshold value (step 422) at present, give system make a period of time its stable after, MPPT control block 304 calculates the present power (step 412) of panel 202 once more, and more present power and previous power (step 414), be in the increase or in reducing to judge panel power.

If MPPT control block 304 is judged present power not greater than previous power (step 414), then MPPT control block 304 is revised conversion proportion with the direction opposite with previous modification, and produces the conversion proportion order of upgrading (step 424).MPPT control block 304 also judges whether equal 2, T revises conversion proportion (step 426) if equal 2 expressions because conversion proportion changed before formerly calculating with the direction opposite with previous calculating if following the trail of variable T.In this case, give system make a period of time its stable after, MPPT control block 304 calculates the present power (step 412) of panel 202 once more, and more present power and previous power (step 414).

Yet, if MPPT control block 304 judges that T is not equal to 2, expression is revised conversion proportion (step 426) because conversion proportion changed before formerly calculating with the direction identical with previous calculating, then MPPT control block setting T is 2, and increases counter (step 428).MPPT control block 304 judges whether counter exceeds counter threshold value C then _Th(step 422) is as above-mentioned.

If counter does not exceed counter threshold value (step 422), the expression conversion proportion alternately changes for several times in first direction and second direction, this number of times is greater than the counter threshold value, MPPT control block 304 is found out the best transition ratio corresponding to the maximum power point of panel 202, and MPPT control block 304 begins to operate in maintenance pattern (step 430).

In the time of in preservation mode, MPPT control block 304 can be set timer and count initialized device (step 432) again.When the timer appointed date (step 434), MPPT control block 304 can revert to tracking pattern (step 436).And calculate present power (step 412), the last power (step 414) that calculates in the tracking pattern with more present power and MPPT control block 304.In this way, MPPT control block 304 can be guaranteed can not change the best transition ratio, or when the condition changing of panel 202, can find out different best transition ratios.

Although Fig. 4 A shows the example of the method 400 of the maximum power point be used to follow the trail of energy producing unit 202, can make various changes to method 400.For example, although be reference light voltaic panel and describing method 400, method 400 can be used for other energy producing unit 202, for example wind turbine, fuel cell etc.Further, although be with reference to the MPPT of Fig. 3 control block 304 and describing method 400 should be appreciated that, within the scope that does not break away from disclosure, method 400 can be used for any MPPT control block that is provided with suitably.In addition, for some embodiment, in step 430, if MPPT control block 304 judges that the best transition ratio is equivalent to the lifting pattern of power stage 206, MPPT control block 304 can operate in park mode but not the maintenance pattern.For these embodiment, after the park mode, the time of timer appointed date can be identical or different with the time of the timer that keeps pattern.And although be to show with a series of step, the step in the method 400 can overlap, parallel generation, take place repeatedly or with different order to take place.

Fig. 4 B is another embodiment according to disclosure, is presented at the method 450 that realizes MPPT in the local transitions device 204.For a specific embodiment, the method 450 of Fig. 4 B can be wherein a part of corresponding to the method 400 of Fig. 4 A.For example, as the method 450 described step 1 be step 403,408,410,412,414,416, and 424 corresponding to method 400.Yet method 450 comprises the additional detail except these steps.For another specific embodiment, method 450 can be independent of method 400 to be implemented, and is not limited to the implementation method of said method 400.In addition, as method 400, the following stated method 450 only is an illustrative.Within the scope that does not break away from disclosure, but other embodiment of implementation method 450.

Method 450 with comprise step 452,454, and 456 start group to start with.Just begin, it is minimum transition ratio M that MPPT control block 304 is set transducer conversion proportion M _Min(step 452).Then, MPPT control block 304 is set previous transducer conversion proportion M _OldBe M, M _OldFor being used for last MPPT conversion proportion repeatedly, and to set conversion proportion M repeatedly for present MPPT be M _Old+ Δ M, wherein Δ M is the increase residual quantity (step 454) of each conversion proportion between repeatedly.If the M value that sets in this step is less than initial conversion ratio M _StartValue, to be used to implement MPPT (step 456), then, M _OldAnd M makes both all increase Δ M (step 454) all as above-mentioned renewal.In case the M value meets or exceeds M _StartValue (step 456), then start group is just finished, and method proceeds to step 458.

It is M that MPPT control block 304 is set the M value _Start, and the value of setting " symbol " is 1, each time MPPT perturbation direction (step 458) repeatedly during the value representation MPPT of symbol handles.At this moment, MPPT control block 304 sensing ADC, 306 input voltage supplied and electric current (V _InAnd I _In), and the output voltage and the electric current (V of sensing ADC 308 supplies _OutAnd I _Out) (step 460).MPPT control block 304 also calculates average input voltage and electric current (V _{In av}And I _{In av}), and average output voltage and electric current (V _{Out av}And I _{Out av}), afterwards, with V _{In av}* I _{In av}Calculate input power (step 460).

For some embodiment, average input voltage and electric current and average output voltage and electric current tie up to MPPT disturbance second half calculating at interval.For the specific embodiment with 50MHz frequency, input voltage and electric current can be taken a sample at 12.5kHz, and calculate average input voltage and electric current and average output voltage and electric current at 750Hz.

Then, before activation MPPT handled, MPPT control block 304 judged whether temperature and electric current are acceptable (step 462).For a specific embodiment, MPPT control block 304 comprises when temperature exceeds predetermined threshold value, can receive the overheated pin of heat alarm.For this embodiment, when heat alarm was represented to exceed threshold value, MPPT control block 304 judged that temperature is unacceptable.

For a specific embodiment, MPPT control block 304 can be by comparing output current I _OutWith average input current I _{In av}Upper limit I with less electric current threshold value _{Min hi}And judge whether electric current is acceptable, guaranteeing that output current and average input current serve as enough before beginning MPPT handles, and by average output current I _{Out av}Output current I with maximum _{Out max}, can be too not high to guarantee average output current.For this embodiment, when output current and average input current all greater than the upper limit of less electric current threshold value, and when average output current during less than maximum output current, MPPT control block 304 judgement electric currents are acceptable.Perhaps, when output current or average input current are less than the upper limit of minimum current threshold value, or when average output current during greater than the output current of maximum, MPPT control block 304 judges that electric currents are unacceptable.

For a specific embodiment, MPPT control block 304 also can comprise the overcurrent pin, and when average output current exceeded maximum output current, the overcurrent pin can receive overcurrent signal.For example, can specify the value of maximum output current to give the overcurrent pin via resistance divider.Then, when exceeding maximum output current, the overcurrent pin can receive overcurrent signal.

When MPPT control block 304 judges that temperature and/or electric current are unacceptable (step 462), reset the M value and be M _Start, and to reset " symbol " value be 1 (step 458).When setting M value is M in that temperature is too high _StartShi Tongchang can cause the guidance panel 202 away from MPPT, thereby reduces the power that transducer 204 is transmitted.In addition, can be with M _StartBe chosen as the operating point of the loss that minimizes local transitions device 204.For example, for a specific embodiment, can select M _StartBe 1.Therefore, when temperature is unacceptable when too high, regression M _StartGenerally can cause because power reduces descends temperature.In addition, when the output short-circuit circuit caused average output current too high, setting the M value was M _StartCan cause panel voltage to force to be made as zero.

Judge temperature and electric current when MPPT control block 304 and be all (step 462) can accept the time, then activation MPPT handles.For above-mentioned specific embodiment, when temperature and average output current are all enough low, and output current and average input current are all enough when high, and MPPT control block 304 judges that temperature and electric current are acceptable.Like this then cause the start between local transitions device 204 and DC- AC transducer 22 or 112 and stop synchronous ability.For this embodiment, when start, each local transitions device 204 is fixing conversion proportion, and operates in this state a period of time, and this time is enough to make system 10 or 100 to become stable state.If DC- AC transducer 22 or 112 does not begin its operation at this moment, then local transitions device 204 its electric capacity of meeting quick charge are to fixed voltage.For example, this fixed voltage can be by the panel voltage and the initial conversion ratio M of open circuit _StartGiven.In case reach this state, then the input of local transitions device 204 and output current are virtual zero.

For this embodiment, can and only when current sensor exceeds specific threshold value, allow MPPT and provide synchronous by the output of sensing local transitions device 204 (or input) electric current.When DC- AC transducer 22 or 112 beginning normal operations, the output of local transitions device 204 (or input) electric current surpasses minimum threshold value, and all local transitions devices 204 begin its MPPT operation in DC-AC transducer 22 or its MPPT operation of 112 beginnings.Same, when because any former thereby when interrupting DC-AC transducer 22 or 112 (for example isolated), the constructed local transitions device 204 that makes stops synchronously.

For the method 450 of Fig. 4 B, MPPT handles with previous input power P _{In old}Be set at present input power Pin (step 464) to start with.Therefore, when just beginning, previous input power is set at the value of the input power that step 460 calculates.It is M that MPPT control square 304 is set the M value _Old+ value of symbol * Δ M is then with M _OldValue be set at M (step 466).Therefore, conversion proportion is adjusted Δ M, by with M with the direction that value of symbol is specified _OldValue is changed into identical value, can use final conversion proportion in repeatedly follow-up.

Then, MPPT control block 304 judges whether conversion proportion M drops within the preset range, and whether average output voltage is too high.For described embodiment, when conversion proportion is less than maximum conversion proportion M _MaxAnd compare M greater than minimum transition _MinThe time, conversion proportion is for dropping within the preset range.And for described embodiment, when average output voltage exceeds maximum output voltage V _{Out max}The time, average output voltage is considered as too high.

Therefore, if M greater than M _MaxOr V _{Out av}Greater than V _{Out max}(step 468), then MPPT control block 304 is set at value of symbol-1 (step 470), and it can make that (if proceeding) MPPT handles, and follow-up conversion proportion in repeatedly reduces, and more elaborates as following.Similarly, if M less than M _Min(step 472), then to set values of symbol be 1 (step 474) to MPPT control block 304, it can cause that (if proceeding) MPPT handles, and follow-up conversion proportion in repeatedly increases, and more elaborates as following.

Therefore, when average output voltage during greater than maximum output voltage (step 470), it is not the switch of simply closing in the switch process, but allow that local transitions device 204 continues operation, and can control block 304 by MPPT and reduce conversion proportion and avoid local transitions device 204 to exceed maximum output voltage.Even so advantage is still can allow average collection of energy generally causing average output voltage to exceed under the very big mismatch condition of rated voltage of some member.

At this moment, MPPT control block 304 sensing ADC, 306 input voltage supplied and electric current (V _InAnd I _In), and the output voltage and the electric current (V of sensing ADC 308 supplies _OutAnd I _Out) (step 476).MPPT control block 304 also calculates average input voltage and electric current (V _{In av}And I _{In av}), and average output voltage and electric current (V _{Out av}And I _{Out av}), afterwards, with V _{In av}* I _{In av}Calculate input power (step 476).

Then, MPPT control block 304 is judged present input power P _InWhether greater than previous input power P _{In old}, it is to calculate (step 478) last in repeatedly.If present input power is greater than previous input power (step 478), then to decide value of symbol by house be (symbol to MPPT control block 304 _Old) change the value of " symbol ", wherein symbol _OldFor multiply by the present value of symbol (step 480) before-1.Therefore, MPPT handle follow-up repeatedly in, compared with if MPPT handle continue at present repeatedly, conversion proportion is revised with different directions, is described in more detail as following.

If present input power is greater than previous input power (step 478), then MPPT control block 304 keeps the value (step 482) of " symbol ".Therefore, MPPT handle follow-up repeatedly in, compared with if MPPT handle continue at present repeatedly, conversion proportion is revised with identical direction, is described in more detail as following.

MPPT control block 304 judges whether temperature and electric current handle receptible (step 484) by continuing MPPT.For above-mentioned specific embodiment (wherein MPPT control block 304 comprises overheated pin), when heat alarm was represented to exceed threshold value, MPPT control block 304 decidable temperature were unacceptable

For a specific embodiment, MPPT control block 304 can be by comparing output current I _OutAnd average input current I _{In av}With minimum current threshold value lower limit I _{Min, low}, judge whether electric current is acceptable, continuing before MPPT handles guaranteeing, output current and average current input are all enough high, and by average output current I relatively _{Out, av}With maximum output current I _{Out, max}, not too large to guarantee average output current.For this embodiment, when output current and/or average input current greater than minimum current threshold value lower limit, and when average output current was less than maximum output current, MPPT control block 304 judged that these electric currents are acceptable.Perhaps, when output current and average input current all are less than the lower limit of minimum current threshold value, or when average output current during greater than maximum output current, MPPT control block 304 judges that these electric currents are unacceptable.Handle (step 462) with activation MPPT and use the lower limit of minimum current threshold value to stop MPPT processing (step 484) by the upper limit of using the minimum current threshold value, so, MPPT control block 304 can avoid the MPPT processing repeatedly to begin and stop, if what output and average input current during near the single electric current threshold value that is used for activation and stops that MPPT handles, might take place that MPPT handles repeatedly begins and stops.

Judge temperature and/or electric current for can not accept the time (step 484) when MPPT control block 304, stop MPPT and handle.At this moment, the M value is reset to M _Start, and " symbol " value is reset to 1 (step 458), and the method continues as before.Judge temperature and electric current when MPPT control block 304 and be all (step 484) to accept the time, the value P of previous input power _{In old}Be set at the value P of present input power _In(step 464), and MPPT control block 304 beginning MPPT handle repeatedly follow-up, as described above.

Although Fig. 4 B is the method 450 of Display Realization to the MPPT of energy producing unit 202, can make various changes for method 450.For example, although be with reference to the photovoltaic panel and illustration method 450, method 450 can be used for other energy producing unit 202, for example wind turbine, fuel cell etc.Further, although be with reference to the MPPT of Fig. 3 control block 304 and illustration method 450 should be appreciated that, within the scope that does not break away from disclosure, method 450 can be used in the MPPT control block of any suitable setting.And though the those shown is a series of step, the step in the method 450 can overlap, parallel generation, take place repeatedly or with different order to take place.For a specific embodiment, should be appreciated that, in MPPT handles, be not in each time repeatedly, only to implement once, but can be constantly relevant temperature in MPPT control block 304 implementation steps 484 and the acceptability judgement of electric current.

Fig. 5 is the embodiment according to disclosure, show energy production system 500, energy production system 500 comprises most energy producing units 502 and central array controller 510, and central array controller 510 can be for energy production system 100 choice set Chinese styles or distributed MPPT.For described embodiment, energy production system refers to photovoltaic system 500, and photovoltaic system 500 comprises the array that photovoltaic panel 502 is formed, and photovoltaic panel 502 each coupling are all to a local transitions device 504.

Each local transitions device 504 comprises a power stage 506 and a local control 508.In addition, for some embodiment, can walk around each local transitions device 504 via the internal switch of selecting for use (for example switch 312).When being bypassed, the output voltage of local transitions device 504 equals its input voltage in fact.In this way, the loss of the operation of relevant local transitions device 504 can be minimized even be eliminated (when not needing local transitions device 504).

Except central array controller 510, the embodiment of system 500 also comprises switching stage 512, grid 514, reaches data/address bus 516.Central authorities' array controller 510 comprises a diagnostic module 520, a control module 525 and the switching stage of selecting for use (CS) optimizer 530.In addition, described embodiment is provided with total body controller 540 to switching stage 512.Yet, should be appreciated that total body controller 540 can be located in the central array controller 510, but not is located in the switching stage 512.And CS optimizer 530 can be located in the switching stage 512, but not is located in the central array controller 510.

For some embodiment, panel 502 and local transitions device 504 are represented the panel 202 and the local transitions device 204 of the panel 102 of Figure 1B and local transitions device 104 and/or representative graph 2 or 3, central authorities' array controller 510 can be represented the central array controller 110 of Figure 1B, and/or switching stage 512 can be represented the DC-AC transducer 112 of Figure 1B.In addition, diagnostic module 520 and control module 525 can be represented diagnostic module 120 and the control module 125 of Figure 1B respectively.Yet, should be appreciated that the member of system 500 can be realized in any suitable manner.Switching stage 512 can comprise DC-AC transducer, battery charger or other energy accumulating device, or any other suitable member.Grid 514 can comprise any suitable load that can operate according to the energy that photovoltaic system 500 produces.

Each local control 508 can provide the data of corresponding panel device and local transitions device data to give central array controller 510 via data/address bus 516 or via wireless connections.According to these data, diagnostic module 520 can judge whether panel 502 operates under the accurate desirable condition, that is panel 502 can mate, and is illuminated in fact equably.In this case, diagnostic module 520 can impel control module 525 that system 500 is placed centralized MPPT (CMPPT) pattern.In order to finish this kind state, control module 525 can transmit stop signal to each local control 508 via data/address bus 516, with by operating local transitions device 504 in bypass mode, stops local transitions device 504.Control module 525 also can transmit enable signal to total body controller 540.

In bypass mode, local control 508 is no longer implemented MPPT, and the output voltage of power stage 506 equals the panel voltage of panel 502 in fact.Therefore, can minimize loss relevant for operation local transitions device 504, and the usefulness of energy maximization system 500.When authorities' book transducer 504 operated in the bypass mode, the array that total body controller 540 energy counter plates 502 are formed was implemented CMPPT.

Diagnostic module 520 also can be judged whether crested or do not match (that is, compare with other panel 502 in the array, some panel 502 has different characteristic) of some panel 502.In this case, diagnostic module 520 can impel control module 525 that system 500 is placed distributed MPPT (DMPPT) pattern.In order to finish this state, control module 525 can transmit enable signals to each local control 508 via data/address bus 516, with by the normal operations of allowing local transitions device 504, and activation local transitions device 504.Control module 525 also can transmit stop signal to total body controller 540.

When some panel 502 crested, diagnostic module 520 also can judge that the panel 502 of some crested is partly crested.In this case, except impelling control module 525 that system 500 is placed the DMPPT pattern, diagnostic module 410 also can be implemented complete diagnostic scan to system 500, guaranteeing that partly the local control 508 of the panel 502 of crested can find real maximum power point, but not local maximum.For the embodiment that energy producing unit 502 wherein comprises wind turbine, whether diagnostic module 520 can be judged because change wind-force pattern, hills or other stops wind structure, or other influences wind condition and causes some wind turbine " crested ".

The situation that explanation photovoltaic system 500 is partly covered in Fig. 6 and 7A-C.Fig. 6 is presented at the photovoltaic array 600 under the situation of partly crested.Fig. 7 A-C is for showing corresponding to the voltage of three photovoltaic panels of Fig. 6 Figure 70 0,705 of power characteristic, and 710.

Described array has three strings 610 that are provided with the photovoltaic panel.Three panels in string 610c are denoted as panel A, panel B, reach panel C.Should be appreciated that, but the panel 502 of these panel representative graphs 5 or the panel in other any photovoltaic system that is provided with suitably.Some panel crested zone 620 covers fully or partly covers.

In described embodiment, panel A is fully illuminated, and partly cover in panel B crested zone 620, and cover fully in panel C crested zone 620.Voltage among Figure 70 0 among Fig. 7 A to power characteristic corresponding to panel A, the voltage of the Figure 70 5 among Fig. 7 B to power characteristic corresponding to panel B, and the voltage of Figure 71 among Fig. 7 C 0 to power characteristic corresponding to panel C.

Therefore, shown in Figure 70 5, the panel B that is partly covered has the local maximum 720 different with actual maximum power point 725.The diagnostic module 520 of central authorities' array controller 510 can judge that panel B is partly covered, and implements full diagnostic scan, operate at its actual maximum power point 725 for its local control 508 to guarantee panel B, and non local maximum point 720.Replace and to operate in actual maximum power point (for example putting 725), and the panel 502 that operates in local maximum power point (for example putting 720) is called as the panel 502 of " under the operation ".

For a specific embodiment, the panel 502 that diagnostic module 520 can following identification be partly covered.At first, diagnostic module 520 hypothesis panels 1 ..., N by the sub-portfolio of the panel 502 in the consideration array, it has identical characteristic, and hypothesis P _{Pan, i}For belong to combination [1 ..., N] the power output of i panel 502.Therefore, P _{Pan, max}〉=P _{Pan, i}〉=P _{Pan, min}P wherein _{Pan, max}Be the power output of the best enforcement panel 502, P _{Pan, min}Power output for the poorest enforcement panel 502.

Diagnostic module 520 also defines a variable φ by following formula _i:

${\mathrm{\φ}}_i=\frac{P_{\mathrm{pan}\max }-P_{\mathrm{pani}}}{P_{\mathrm{pan}\max }}$

I panel 502 probability whole or partly crested can be expressed from the next:

Wherein, k is less than or equals 1 constant.Then be: ρ _Min≤ ρ _i≤ ρ _Max

Wherein, ${\mathrm{\ρ}}_{\min }=\frac{k(P_{\mathrm{pan}\max }-P_{\mathrm{pan}\max })}{P_{\mathrm{pan}\max }}=0$ And ${\mathrm{\ρ}}_{\max }=\frac{k(P_{\mathrm{pan}\max }-P_{\mathrm{pan}\min })}{P_{\mathrm{pan}\max }}.$

Diagnostic module 520 also defines (ρ _DMPPT) be probability function (ρ _Max) minimum value, it is necessary making DMPPT.Therefore, if (ρ _Max) greater than (ρ _DMPPT), then can activation DMPPT.In addition, with (ρ _Diag) be defined as probability function (ρ _Max) minimum value so that the diagnosis function is necessary, it is any panel 502 in order to judge that the quilt do not operate in MPP partly covers.Therefore, if (ρ _Max) greater than (ρ _Diag), then diagnostic module 520 is recognized as panel 502 and is partly covered, and can implement scanning for the panel 502 that picks out.

For not the matching of relatively very little panel 502, but diagnostic module 520 activation DMPPT still, but for bigger not matching, diagnostic module 520 also can be implemented full diagnostic scan.Just itself, (ρ _DMPPT) value usually less than (ρ _Diag) value.

Therefore, for some embodiment, as (ρ _Max)＜(ρ _DMPPT) time, diagnostic module 520 can decision-making system 500 should operate in the CMPPT pattern, as (ρ _DMPPT)＜(ρ _Max)＜(ρ _Diag) time, system 500 should operate in the DMPPT pattern, and as (ρ _Max)＞(ρ _Diag) time, system 500 should operate in the DMPPT pattern together with full diagnostic scan.

For these embodiment, full diagnostic scan can comprise (ρ _j＞ρ _Diag) voltage of each panel j is to the complete scan of power characteristic.Diagnostic module 520 can be individually according to central array controller 510 given sequential scan the characteristic of each panel 502.In this mode, switching stage 512 sustainable operations normally.

When system 500 operates in the DMPPT pattern, the operating point of CS optimizer 530 energy optimization switching stages 512.For an embodiment, the operating point of switching stage 512 can be set at constant.Yet, for the embodiment that uses CS optimizer 530, can be by the operating point of CS optimizer 530 optimization switching stages 512.

For a specific embodiment, CS optimizer 530 can be as the optimization operating point of following judgement switching stage 512.For i power stage 506, its work period is defined as D _i, and its conversion proportion is defined as M (D _i).Power stage 506 is designed to have nominal conversion proportion M ₀Therefore, approach M as much as possible ₀And operand power level 506 can provide higher efficient, reduces pressure, and reduces the saturated possibility of output voltage.For the power stage 506 that comprises stepwise lifting transducer, M ₀Can be 1.

Therefore, optimized principle can be defined as follows:

$\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}M\left(D_i\right)}{N}=M_0$

Then,

$\underset{i=1}{\overset{N}{\mathrm{\Σ}}}M\left(D_i\right)=\underset{i=1}{\overset{N}{\mathrm{\Σ}}}\frac{I_{\mathrm{pan},i}}{I_{\mathrm{out},i}}{\mathrm{\η}}_i\≈\frac{1}{I_{\mathrm{LOAD}}}\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{I}_{\mathrm{pan},i}$

Wherein, I _{Pan, i}Be the input current of i power stage 506, I _{Out, i}Be the output current of i power stage 506, η _iBe the efficient of i power stage 506, I _LOADIt is the input current of switching stage 512.Therefore, optimized principle can be write as follows again:

$I_{\mathrm{LOAD}}=\frac{\underset{i=1}{\overset{N}{\mathrm{\Σ}}}{I}_{\mathrm{pan},i}}{{\mathrm{NM}}_0}$

CS optimizer 530 can use normalized current pattern control technology by the input port in switching stage 512 and reach optimization, makes the input current of switching stage 512 be set at I _LOAD

Fig. 8 is the embodiment according to disclosure, shows the method 800 for energy production system 500 choice set Chinese style MPPT or distributed MPPT.The embodiment of method 800 only is an illustrative.Can be within the scope that does not break away from disclosure other embodiment of implementation method 800.

Method 800 is set timer (step 802) to start with diagnostic module 520.Diagnostic module 520 can use timer in a looping fashion and the initialization of triggering method 800.Then, the energy producing unit in diagnostic module 520 analytical systems 500, for example panel 502 (step 804).For example, for some embodiment, diagnostic module 520 can be by the panel power P of calculating each panel 502 _PanAnd analyze panel 502, then according to P _PanThese calculated values judge several other values, as described in above relevant Fig. 5.For example, diagnostic module 520 decidable calculated value P _PanMaximum and minimum value (be respectively P _{Pan, max}And P _{Pan, min}), the probability (ρ) of then using these maximums and minimum value to be covered fully or partly cover to calculate each panel 502.Diagnostic module 520 also can determine the maximum (ρ of institute's calculator rate _Max).

Analyzing panel 502 (step 804) afterwards, whether diagnostic module 520 decidable photovoltaic systems 500 operate under the accurate desirable condition (step 806).For example, for some embodiment, diagnostic module 520 can be with the maximum (ρ of the panel 502 crested probability that calculate _Max) and be scheduled to DMPP and face limit (ρ _DMPPT) give comparison.If ρ _MaxLess than ρ _DMPPT, then the peak power output of panel 502 and minimum output power are enough approaching, therefore, not matching between the panel 502 can be considered as minimumly, and system 500 can be considered and operates in accurate perfect condition.Similarly, if ρ- _Max, be not less than peak power output (ρ _DMPPT), then the peak power output of panel 502 and minimum output power differ enough far away, and it is minimum to make that not matching between the panel 502 can not be considered as, and system 500 is considered as not operating under accurate ideal conditions.

If diagnostic module 520 decision-making systems 500 do not operate under the accurate ideal conditions (step 806), control module 525 activation local controls 508 (step 808) then, and stop total body controller 540 (step 810), by this system 500 is located in the DMPPT pattern.Therefore, in this case, local control 508 is implemented MPPT to each panel 502.

Because be not match situation and use the DMPPT pattern very for a short time relatively for having between the panel 502, even then when the probability of the panel 502 of crested is low (but not being extremely low), diagnostic module 520 decidable systems 500 are not for operating under the accurate ideal conditions.Therefore, after entering the DMPPT pattern, diagnostic module 520 judges whether the probability of the panel 502 of crested is high (step 812).For example, the diagnostic module 520 maximum (ρ that panel 502 can be covered _Max) face limit (ρ with predetermined diagnosis _Diag) give comparison.If ρ _MaxGreater than ρ _Diag, then the peak power output of panel 502 and minimum output power differ enough big, make unmatched probability between the panel 502 high under being considered as relatively, and therefore, the probability of at least one panel 502 crested is very high.

If the probability very high (step 812) of panel 502 cresteds, then diagnostic module 520 is implemented omnicharacteristics scannings (step 814) for any one panel 502 of possible crested.For example, diagnostic module 520 can be by relatively limit (ρ is faced in the probability (ρ) and the diagnosis of panel crested for each panel 502 _Diag), and pick out may crested panel 502.If particular panel 502 is greater than ρ _Diag, then the peak power output of the panel 502 in the power output of particular panel 502 and the system 500 differs enough big, and then particular panel 502 probability of partly being covered at least is relatively very high.

When implementing omnicharacteristic scanning, the sequential that diagnostic module 520 can be provided according to central array controller 510 is individually implemented voltage for each panel 502 that might crested power characteristic is scanned.In this mode, switching stage 512 can continue normally to operate in scan period.

If in during any omnicharacteristic scanning of enforcement, diagnostic module 520 judges that arbitrary panel 502 is in force (promptly, operate in local maximum power point (MPP), for example local MPP 720, but not actual MPP, MPP725 for example), the panel 502 during then control module 525 can be implemented for these provide correction (step 816).

If at this moment, or the probability not high (step 812) of panel 502 cresteds, diagnostic module 520 is judged timers appointed date (step 818) whether, and method for expressing 800 must be initialised once more.In case the timer appointed date (step 818), diagnostic module 520 is promptly reseted timer (step 820), and panel 502 (step 804) is analyzed in beginning once more.

If diagnostic module 520 decision-making systems 500 operate under the accurate ideal conditions (step 806), then control module 525 stops local control 508 (step 822) and the total body controller 540 of activation (step 824), whereby system 500 is located in the CMPPT pattern.Therefore, in this case, total 540 pairs of whole systems of body controller 500 are implemented MPPT.

And at this moment, diagnostic module 520 is judged timers appointed date (step 818) whether, and method for expressing 800 must be initialised once more.In case the timer appointed date (step 818), diagnostic module 520 is promptly reseted timer (step 820), and panel 502 (step 804) is analyzed in beginning once more.

Although Fig. 8 has shown the example of choice set Chinese style or the method for distributed MPPT 800, can make various changes for method 800.For example, although be to cooperate the photovoltaic system and describing method 800, method 800 still can be used for other energy production system 500, for example wind turbine system, fuel cell system.Further, although be to cooperate the system 500 of Fig. 5 and describing method 800 should be appreciated that, within the scope that does not break away from disclosure, method 800 can be used for any energy production system that is provided with suitably.In addition, although the those shown is a succession of step, the step in the method 800 can overlap, parallel generation, take place repeatedly or with different order to take place.

Fig. 9 is the embodiment according to disclosure, shows in order to start and to stop the system 900 of the local control 908 of a local transitions device 904 in energy production system.System 900 comprises energy producing unit 902 (being called as photovoltaic panel 902), and local transitions device 904.Local transitions device 904 comprises power stage 906, local control 908 and starter 910.

Local transitions device 904 can represent among Figure 1B local transitions device 104, the local transitions device among Fig. 2 or 3 204 one of them, and/or Fig. 5 local transitions device 504 one of them, yet, should be appreciated that, within the scope that does not break away from disclosure, local transitions device 904 can be implemented in any suitable setting in the energy production system.Therefore, should be appreciated that, but system's 900 coupled in series and/or coupled in parallel produce array to other similar system 900 to form energy.

For described embodiment, starter 910 is to be coupled between panel 902 and the local control 908.For some embodiment, starter 910 can start and stop local control 908 according to the output voltage of panel 902.When the output voltage of panel 902 was too low, starter 910 can provide and be essentially zero service voltage to local control 908, closes local control 908 by this.When the output voltage of panel 902 was higher, starter 910 can provide the service voltage of non-zero to local control 908, so that local control 908 is running.

Should be appreciated that except providing service voltage to local control 908, starter 910 can start and stop local control 908 in any suitable manner.For example, for a replaceability embodiment, starter 910 can be set one or more pin of local control 908, to start and to stop local control 908.For another replaceability embodiment, starter 910 can write first predetermined value first buffer in the local control 908, to start local control 908, and second predetermined value (according to the particular implementation means and can be identical with first predetermined value or different) write first buffer or second buffer in the local control 908, to stop local control 908.

Therefore, system 900 does not use battery or external power source just can make the 904 spontaneous operations of local transitions device.When solar radiation is enough high, output slab voltage V _PanBe increased to the service voltage V that makes starter 910 begin to produce non-zero _CCThe position accurate.At this moment, local control 908 and/or central array controller (showing among Fig. 9) can come into effect start-up routine, the for example initialization of buffer, preliminary voltage ratio between the panel 902, the AD converter calibration, Frequency Synchronization or frequency are inserted, power stage 906 and/or be the synchronous startup etc. of central array controller.Similarly, before halt system 900, can implement shut down procedure, for example in independent applicable cases, with the synchronization of backup units, with stopping synchronously etc. of power stage 906.During these shut down procedures, starter 910 still can keep this as starting.

In addition, for some embodiment, starter 910 can provide overpower protection to local transducer 904.As the above-mentioned explanation relevant, for the MPPT control block 604 of the some of local control 208 can provide overpower protection with Fig. 3.Yet,, be that starter 910 can provide this kind defencive function on the contrary as the replaceability embodiment of the system that comprises starter 910.Therefore, for this replaceability embodiment, too low if output current drops to, then starter 910 may be closed the MPPT function of local control 908, makes panel voltage V _PanOutput voltage V no better than _Out

Figure 10 is the embodiment according to disclosure, Figure 92 0 that the device voltage of display system 900 changed along with the time.For photovoltaic panel 902, in solar radiation position standard at the voltage starting position of starter 910 standard (V _T-on) near the vibration situation in, use identical voltage starting position standard as voltage position of rest standard (V _T-off) can the undesired system of generation start for more than 900 time and stop.Therefore, shown in Figure 92 0, use lower voltage position of rest standard, to avoid this kind phenomenon.By using lower voltage position of rest standard, system 900 can keep consistent startup, up to the solar radiation position accurate fully descend make panel voltage drop to be lower than voltage starting position standard till.Therefore, can avoid frequent startup and stop, and provide the noise immunity system 900.

For some embodiment, after panel voltage exceeds the voltage starting position standard that makes local control 908 startups, if panel voltage drops to and is lower than voltage starting position standard, local control 908 beginning shut down procedures then are lower than the voltage position of rest and stop more quickly on time can ratio panels voltage to continue to drop to.In addition, for some embodiment, before arriving voltage position of rest standard, in some cases, local control 908 can cut out starter 910 and itself.

Figure 11 is the embodiment according to disclosure, shows starter 910.For this embodiment, starter 910 comprises power supply 930, most resistance R 1, R2, R3 and diode D.Resistance R 1 and R2 coupled in series are between the input node (IN) and ground of power supply 930.Diode and resistance R 3 coupled in series are between the output node (OUT) and node 940 of power supply 930, and resistor R 1 and R2 couple at node 940.In addition, the termination node (SD) of power supply 930 also is coupled to node 940.

Power supply 930 can receive panel voltage V at the input node _Pan, and at the supply voltage V of output node generation for local control 908 _CCIf the voltage V of the voltage level overshoot of the termination node that the control circuit of power supply 930 is judged ₀, the then operation of the termination node activation power supply 930 of power supply 930, and if the voltage level of termination node drops to the voltage V that is lower than regulation ₀, then end the operation of node stop power supply 930.

When power supply 930 was closed, diode can conducting, and the voltage of ending node is represented with following formula:

$V_{\mathrm{SD},t-\mathrm{on}}=V_{\mathrm{pan}}\frac{R_2}{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001278957700051.png,HPA00001278957700061.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HPA00001278957700051.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}$

As voltage V _SDt-onExceed value V ₀The time, diode begins conducting, and the voltage of termination node becomes:

$V_{\mathrm{SD},t-\mathrm{off}}={\mathrm{<figure-callout\; id="2"\; label="V\; pan\; R"\; filenames="HPA00001278957700051.png"\; state="\{\{state\}\}">V</figure-callout>}}_{\mathrm{pan}}\frac{R_{}}{}\frac{{}_2//R_3}{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001278957700051.png,HPA00001278957700061.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HPA00001278957700051.png"\; state="\{\{state\}\}">R</figure-callout>}}_2//R_3}+(V_{\mathrm{CC}}-V_d)\frac{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001278957700051.png,HPA00001278957700061.png"\; state="\{\{state\}\}">R</figure-callout>}}_1//R_2}{R_3+{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="HPA00001278957700051.png,HPA00001278957700061.png"\; state="\{\{state\}\}">R</figure-callout>}}_1//{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="HPA00001278957700051.png"\; state="\{\{state\}\}">R</figure-callout>}}_2}$

Wherein, V _dBe diode drop, and

As voltage V _{SD, t-off}Drop to and be lower than V ₀The time, power supply 930 is closed.Therefore can judge according to the resistance value of resistance R 1, R2 and R3 and open and close the voltage threshold value.

Figure 12 is the embodiment according to disclosure, shows in order to start and to stop the method 1200 of local transitions device 904.The embodiment of method 1200 only is an illustrative.Can be in the scope that does not break away from disclosure other embodiment of implementation method 1200.

Method 1200 operates in open-circuit condition (step 1202) to start with energy producing unit or panel 902.In this condition, because the panel voltage of panel 902 outputs is too low, so starter 910 does not start local transitions device 908.Starter 910 monitoring panel voltage (V _Pan) exceed voltage starting position standard (V up to panel voltage _T-on) till (step 1204).

In case starter 910 judges that panel voltage has exceeded voltage starting position standard (step 1204), then starter 910 begins to start local transitions device 904 (step 1206) by opening local control 908.For example, starter 910 can be by the service voltage V that produces non-zero for local control 908 _CC, and begin to start local transitions device 904.For other embodiment, starter 910 can be by one or more pin of setting local control 908, or by first predetermined value is write in first buffer of local control 908, and begin to start local transitions device 904.Local control 908 and/or central array controller are implemented start-up routine (step 1208) to local transducer 904 then.For example, start-up routine can comprise the initialization of buffer, the preliminary voltage ratio between the panel 902, AD converter calibration, frequency-synchronized or insertion comprise the synchronous startup etc. of a succession of panel of power stage 906.

Local control 908 is with predetermined conversion proportion operand power level 906 (steps 1210), till other power stage 906 in the operation string (step 1212).In case each panel 902 in the string has the power stage 906 (step 1212) in the operation, local control 908 is with panel currents (I _Pan) and starting current position standard (I _Min) give comparison (step 1214).If panel currents is greater than starting current position standard (step 1214), then local control begins normally to operate (step 1216).Therefore, local control 908 beginnings are implemented MPPT for power stage 906.

In this mode, the startup of the whole local controls 908 in the synchronization energy production system automatically.In addition,, then can in each power stage 906, comprise single-way switch (for example switch 314), to allow remaining panel 902 of operation if only there is the sub-portfolio of the panel 902 in the photovoltaic system to produce the high voltage that must be enough to start this starter 910.

Local control 908 continues relatively panel currents and starting current position standard (step 1218).If panel currents is less than starting current position standard (step 1218), then local control 908 settings one stop timer (step 1220).Then, local control 908 is again with predetermined conversion proportion operand power level 906 (steps 1222).Local control 908 and/or to be central array controller implement shut down procedures (step 1224) for local transitions device 904 then.For example, shut down procedure can be included in the situation of stand-alone application, with the synchronization of backup units, with stopping synchronously etc. of power stage 906.

Local control 908 is judged and is stopped timer appointed date (step 1226) whether then.Like this then allow that panel currents rises to the time above starting current position standard.Therefore, local control 908 is prepared for for stopping, but waits for to guarantee and should actual execution stop.

Therefore, as long as stop timer appointed date (step 1226) not as yet, local control 908 still can be granted panel currents and starting current position with relatively (step 1228).If panel currents continues to be held at less than starting current position standard (step 1228), then local control 908 continues wait and stops the timer appointed date (step 1226).If the timer appointed date (step 1226) before, panel currents becomes greater than starting current position standard (step 1228), then local control 908 is by power stage 906 is implemented MPPT and can normally be operated (step 1216) once more.

Yet, if be less than starting current position punctual (step 1228) in panel currents, stop the timer appointed date (step 1226), then local control 908 cuts out power stage 906 and local control 908, and guidance panel 902 (step 1230) under open-circuit condition once more.For some embodiment, starter 910 can be by producing zero supply voltage V _CCGive local control 908 and finish stopping of local transitions device 904.For other embodiment, starter 910 can be by one or more pin of setting local control 908, or by first buffer or second buffer of second predetermined value being write in the local control 908, and finish stopping of local transitions device 904.At this moment, starter 910 is monitored panel voltage once more, till panel voltage exceeds voltage starting position standard (step 1204), reinitializes to start and handles.

Although what Figure 12 showed is in order to start and to stop the example of the method 1200 of local transitions device 904, can make various changes to method 1200.For example, although be to come illustration method 1200 with the photovoltaic panel, method 1200 can be used for other energy producing unit 902, for example wind turbine, fuel cell etc.Further, although be that local control 908 and starter 910 with reference to Fig. 9 comes illustration method 1200, should be appreciated that in the scope that does not break away from disclosure, local control 908 and starter 910 can be used for any energy production system of configuration suitably.And although as shown be a series of step, the step in the method 1200 can overlap, and parallel generation takes place repeatedly, or takes place with different order.

Although above-mentioned explanation is with reference to specific embodiment, but should be appreciated that, described some member, system and method can be used for horizontal strip electrophoresis groove (sub-cell), single battery, panel (that is, battery array), panel array and/or are the systems that the panel array is formed.For example, although above-mentioned local transitions device respectively is connected in a panel, similar system can be embodied as a local transitions device and be connected in each battery in the panel, or a local transitions device is connected in and respectively arranges panel.In addition, above-mentioned some member, system and method can be used for other energy producing unit except the photovoltaic device, for example wind turbine, fuel cell etc.

Useful person is for proposing to be used for some words of this part patent document and the definition of phrase.Term that " couples " and derivative thereof refer to the direct or indirect communication between two or more members, and no matter whether these members are actual contact each other." transmission ", " reception ", the term that reaches " communication " and derivative thereof comprise directly and indirect communication." comprise " term that reaches " comprising " and derivative thereof represent including but not limited to." or " term be inclusive, represent and/or be.The term of " each " represent in the project of indication at least one sub-portfolio wherein each." be relevant to " phrase that reaches " relevant " and derivative thereof with it represent interior in order to comprise, to be included in, with it interconnected, comprise, be included in interior, be connected to or be connected in, be coupled to or be coupled to, with its communication, with its cooperative cooperating, insertion, side by side, approach, be engaged to or be engaged in, have, have certain specific character etc.

Although utilized specific embodiment and related methods explanation disclosure, known this skill person when replacement and the combination that can understand easily these embodiment and method.Therefore, the explanation of above-mentioned exemplary embodiment is not in order to define or to limit disclosure.Can be in spirit that does not break away from disclosure and scope, other change, replacement and rotate also possiblely define as accompanying claim.

Claims (20)

1. method that provides maximum power point tracking (MPPT) to handle for an energy producing unit comprises:

One local transitions device is coupled to this energy producing unit;

Judge whether this local transitions device operates in or be lower than a maximum acceptable temperature;

Judge whether at least one electric current that is associated in this local transitions device is acceptable, and

When judging this local transitions device for operating in or be lower than the acceptable temperature of this maximum, and when judging that this at least one electric current that is associated in this local transitions device is acceptable, this MPPT processing that this local transitions device of activation is interior.

2. the method for claim 1 more comprises, and when judging that this local transitions device is higher than the acceptable temperature of this maximum for operating in, this MPPT that stops in this local transitions device handles.

3. method as claimed in claim 2 more comprises, and when judging that this local transitions device is higher than the acceptable temperature of this maximum for operating in, a conversion proportion of this local transitions device is set at an initial conversion ratio.

4. the method for claim 1 more comprises, and when described at least one electric current that is associated in this local transitions device when judgement was unacceptable, the described MPPT that stops in this local transitions device handled.

5. method as claimed in claim 4, wherein, this at least one electric current that is associated in this local transitions device comprises an average output current of this local transitions device, and wherein when this average output current is less than a maximum output current, judges that this average output current is acceptable.

6. method as claimed in claim 4, wherein, this at least one electric current that is associated in this local transitions device comprises an output current of this local transitions device and an average current input of this local transitions device.

7. method as claimed in claim 6, wherein, when stopping this MPPT processing, according to a minimum current threshold value upper limit, judge that this output current and this average current input are acceptable, and wherein when this MPPT of activation handles,, judge that this output current and this average current input are acceptable according to a minimum current threshold value lower limit.

8. the method for claim 1, wherein, this MPPT handles to comprise an average output voltage and a maximum output voltage is given comparison, and when this average output voltage during greater than this maximum output voltage, when continuing this local transitions device of operation, reduce the conversion proportion that this MPPT handles.

9. method that provides maximum power point tracking (MPPT) to handle for an energy producing unit comprises:

One local transitions device is coupled to this energy producing unit;

Judge whether this local transitions device operates in or be lower than a maximum acceptable temperature;

Whether an average output current of judging this local transitions device is less than a maximum output current;

Whether an output current of judging this local transitions device is acceptable;

Whether an average current input of judging this local transitions device is acceptable; And

When (i) judges that this local transitions device is for operating in or when being lower than the acceptable temperature of this maximum, when (ii) judging this average output current less than this maximum output current, (iii) judge when this output current is acceptable, and judge (iv) when this average current input is acceptable that this MPPT in this local transitions device of activation handles.

10. method as claimed in claim 9, more comprise as (i) and judge that this local transitions device is when operating in greater than the acceptable temperature of this maximum, when (ii) judging this average output current greater than this maximum output current, (iii) judge when this output current is unacceptable, or judge (iv) when this average current input is unacceptable that this MPPT that stops in this local transitions device handles.

11. method as claimed in claim 10, wherein, when stopping this MPPT processing, judge that according to a minimum current threshold value upper limit this output current and this average current input are acceptable, and wherein when this MPPT of activation handles, judge that according to a minimum current threshold value lower limit this output current and this average current input are acceptable.

12. method as claimed in claim 10 more comprises when stopping this MPPT and handle, and a conversion proportion of this local transitions device is set at an initial conversion ratio.

13. method as claimed in claim 9, wherein, this MPPT handles to comprise an average output voltage and a maximum output voltage is given comparison, and when this average output voltage during greater than this maximum output voltage, when continuing this local transitions device of operation, reduce the conversion proportion that this MPPT handles.

14. each person for most energy producing units in the energy generation array provides the system of maximum power point tracking (MPPT), this system comprises a local transitions device that is coupled to this energy producing unit to this energy producing unit respectively, and respectively this local transitions device comprises:

One power stage can receive a device voltage and a device electric current from this energy producing unit, and produce an output voltage and an output current according to this device voltage and this device electric current; And

One local control, being coupled to this power stage also can operate to provide MPPT to this power stage, this local control comprises a MPPT module, can judge whether this local transitions device operates in or be lower than a maximum acceptable temperature, judge whether at least one electric current that is associated in this local transitions device is acceptable, and when judging that this local transitions device is for operating in or being lower than the acceptable temperature of this maximum, and when judging that this at least one electric current that is associated in this local transitions device is acceptable, the MPPT in this local transitions device of activation handles.

15. system as claimed in claim 14, wherein, when judging that this local transitions device is higher than the acceptable temperature of this maximum for operating in, this MPPT that this MPPT module more can stop in this local transitions device handles, and a conversion proportion of this local transitions device is set at an initial conversion ratio.

16. system as claimed in claim 14, wherein, when this at least one electric current that is associated in this local transitions device when judgement was unacceptable, this MPPT that this MPPT module more can stop in this local transitions device handled.

17. system as claimed in claim 16, wherein, this at least one electric current that is associated in this local transitions device comprises an average output current of this local transitions device, and wherein whether this MPPT module more can be by judging this average output current less than a maximum output current, and judges whether this at least one electric current that is associated in this local transitions device is acceptable.

18. system as claimed in claim 17, wherein, this at least one electric current that is associated in this local transitions device more comprises an output current of this local transitions device, an and average current input of this local transitions device, and wherein, when stopping this MPPT processing, this MPPT module more can be by judging whether this output current and this average current input respectively are greater than a minimum current threshold value upper limit, and judge whether this at least one electric current that is associated in this local transitions device is acceptable, and when this MPPT of activation handles, this MPPT module more can whether each be less than a minimum current threshold value lower limit by judging this output current and this average current input, and judges whether this at least one electric current that is associated in this local transitions device is acceptable.

19. system as claimed in claim 14, wherein, described MPPT handles to comprise an average output voltage and a maximum output voltage is given comparison, and when described average output voltage during greater than this maximum output voltage, when continuing this local transitions device of operation, reduce the conversion proportion that described MPPT handles.

20. system as claimed in claim 14, wherein, described homenergic generation device comprises the photovoltaic panel.

Images