CN104423414A

CN104423414A - Control method, control device, control circuit and power generating system

Info

Publication number: CN104423414A
Application number: CN201310397498.5A
Authority: CN
Inventors: 卢章庆; 首福俊; 柳树渡
Original assignee: Emerson Network Power Energy Systems Noth America Inc
Current assignee: Dimension Corp.
Priority date: 2013-09-04
Filing date: 2013-09-04
Publication date: 2015-03-18
Anticipated expiration: 2033-09-04
Also published as: CN104423414B

Abstract

An embodiment of the invention provides a control method, a control device, a control circuit and a power generating system used for solving the problem that existing control circuits track maximum output power of photovoltaic cells, probably resulting in oscillation of output voltage of the photovoltaic cells and even resulting in powering off of the control circuits. The method includes acquiring voltage of maximum power point of one photovoltaic cell according to voltage and current outputted from the photovoltaic cell to an input impedance variable device, and taking the voltage of maximum power point as target voltage; determining the duty ratio according to the voltage difference between the voltage outputted from the photovoltaic cell to the input impedance variable device and the target voltage, and generating an adjustment driving signal according to the determined duty ratio, wherein the adjustment driving signal is used for adjusting input impedance of the input impedance variable device.

Description

A kind of control method, device and control circuit and electricity generation system

Technical field

Technical field of new energy power generation of the present invention, particularly relates to a kind of control method, device and control circuit and electricity generation system.

Background technology

In the process of development new forms of energy, solar energy power generating and wind-power electricity generation are applied widely.For solar photovoltaic generation system, this system follows the trail of solar direction by solar panel, make sunray all the time can vertical irradiation on solar panel, to realize the maximization of photovoltaic generation.Cell panel output characteristics affects larger by the external environmental factor such as intensity of illumination, temperature, therefore its output power has time-variant nonlinear feature, need to change the output voltage of solar panel or electric current or angle of inclination, be operated on best power curve to make it.

MPPT maximum power point tracking (MPPT conventional at present, Maximum Power Point Tracking) method has constant voltage-tracing (CVT, Constant Voltage Tracking) method, (Pertubation & Observation) method, conductance increment algorithm (ICA, Incremental Conductance Algorithms) etc. are observed in disturbance.Solar power system of the prior art generally includes photovoltaic cell (photovoltaic cell normally several pieces of solar panels is cascaded), each photovoltaic cell can see an energy input module as, for each energy input module, the control circuit be connected with this energy input module obtains the performance number of its current time by the output voltage and output current detecting this energy input module, if the performance number of current time is greater than the performance number of previous moment, then illustrate when perturbation direction in forward direction maximum power point adjustment process correct, therefore according to certain step value change voltage or electric current, output power is continued to change to this perturbation direction, otherwise, then output power is carried out disturbance in the opposite direction, so progressively adjust, electricity generation system is finally operated near maximum power point.One of this MPPT maximum power point tracking (MPPT, Maximum Power Point Tracking) method conventional at present just---(Pertubation & Observation) method is observed in disturbance.Conventional MPPT method also has constant voltage to follow the tracks of (CVT, Constant VoltageTracking) method, conductance increment algorithm (ICA, Incremental Conductance Algorithms) etc.

But, when solar power system only adopts MPPT Technical Follow-Up maximum power point, when illumination weakens suddenly, the output voltage of photovoltaic cell can reduce suddenly, if the output voltage of photovoltaic cell is less than the under-voltage shutdown voltage of control circuit, control circuit will be caused to shut down.When the output voltage of photovoltaic cell and output current relation as shown in Figure 1 time, wherein, curve 1 and curve 2 represent the output voltage of photovoltaic cell and the family curve of output current under different illumination intensity respectively, when the output voltage of photovoltaic cell and the family curve of output current are curve 1, the illumination that photovoltaic cell accepts is more weak, when the output voltage of photovoltaic cell and the family curve of output current are curve 2, the illumination that photovoltaic cell accepts is stronger; Under A point and B point represent different illumination intensity respectively, output voltage during photovoltaic cell Maximum Power Output.When the output voltage of photovoltaic cell and the family curve of output current are curve 2, control circuit is by regulating the input impedance of self, photovoltaic cell is made to be operated in maximum power point, i.e. B point, when the intensity of illumination that photovoltaic cell receives weakens suddenly, the output voltage of photovoltaic cell and the family curve of output current become curve 1, but because control circuit adjusts the input impedance of self by following the tracks of maximum power point, the speed of adjustment is slow, usual hundreds of millisecond regulates once, therefore, the input impedance of control circuit has little time to change, namely the load that photovoltaic cell connects remains unchanged, it is still load 2, this makes photovoltaic cell no longer be operated in maximum power point, i.e. A point, but be operated in B ' point, when the intensity of illumination that photovoltaic cell receives is very weak, the voltage that B ' puts may be less than the under-voltage shutdown voltage of control circuit, this can cause control circuit to shut down.In addition, even if the voltage that B ' puts does not cause control circuit to shut down, control circuit normally works, namely the input impedance of self is changed, photovoltaic cell is made to rework at maximum power point A point, if now, the intensity of illumination that photovoltaic cell receives strengthens suddenly, when making the output voltage of photovoltaic cell and the family curve of output current be curve 2, the input impedance due to control circuit has little time adjustment, therefore, the load of photovoltaic cell is still load 1, this makes photovoltaic cell no longer be operated in maximum power point, i.e. B point, but is operated in A ' point.Therefore, when the intensity of illumination generation flip-flop that photovoltaic cell receives, just easily there is concussion in the voltage that photovoltaic cell exports, and when the intensity of illumination that photovoltaic cell receives reduces suddenly, the output voltage of photovoltaic cell may be less than the under-voltage shutdown voltage of control circuit, thus causes control circuit to shut down.

In sum, existing control circuit is owing to following the tracks of the peak power output of photovoltaic cell, when this may cause the intensity of illumination generation flip-flop received at photovoltaic cell, there is concussion in the voltage that photovoltaic cell exports, and when the intensity of illumination received when photovoltaic cell may be caused to reduce suddenly, the output voltage of photovoltaic cell can be less than the under-voltage shutdown voltage of control circuit, thus causes control circuit to shut down.

Summary of the invention

Embodiments provide a kind of control method, device and control circuit and electricity generation system, in order to solve existing control circuit owing to following the tracks of the peak power output of photovoltaic cell, when this may cause the intensity of illumination generation flip-flop received at photovoltaic cell, there is the problem of shaking in the voltage that photovoltaic cell exports, and when the intensity of illumination received when photovoltaic cell may be caused to reduce suddenly, the output voltage of photovoltaic cell can be less than the under-voltage shutdown voltage of control circuit, thus the problem causing control circuit to shut down.

Based on the problems referred to above, a kind of control method that the embodiment of the present invention provides, comprising:

Output to the voltage and current of input impedance variable device according to photovoltaic cell, obtain the maximum power point voltage of photovoltaic cell, and as target voltage;

Output to the voltage of input impedance variable device and the voltage difference of target voltage according to photovoltaic cell, determine dutycycle, and generate adjustment drive singal, for adjusting the input impedance of input impedance variable device according to the dutycycle determined.

A kind of control device that the embodiment of the present invention provides, comprising:

Acquisition module, for outputting to the voltage and current of input impedance variable device according to photovoltaic cell, obtains the maximum power point voltage of photovoltaic cell, and as target voltage;

Determination module, for outputting to the voltage of input impedance variable device and the voltage difference of target voltage according to photovoltaic cell, determines dutycycle;

Generation module, for generating adjustment drive singal according to the dutycycle determined, for adjusting the input impedance of input impedance variable device.

A kind of control circuit that the embodiment of the present invention provides, comprises MPPT maximum power point tracking MPPT unit, input voltage control module, drives logical block; Described driving logical block connects described input voltage control module and input impedance variable device respectively, and described MPPT unit connects described input impedance variable device and described input voltage control module respectively;

Described MPPT unit, for outputting to the voltage and current of input impedance variable device according to photovoltaic cell, obtains the maximum power point voltage of photovoltaic cell, and exports to described input voltage control module as target voltage;

Described input voltage control module, for the difference determination dutycycle of the voltage and target voltage that output to described input impedance variable device according to photovoltaic cell, and exports to described driving logical block;

Described driving logical block, for generating adjustment drive singal according to the dutycycle received, and exports to described input impedance variable device, for adjusting the input impedance of input impedance variable device.

A kind of electricity generation system that the embodiment of the present invention also provides, comprises the control circuit that the embodiment of the present invention provides.

The beneficial effect of the embodiment of the present invention comprises:

Embodiments provide a kind of control method, device and control circuit and electricity generation system, according to the maximum functional point voltage of the voltage and current acquisition photovoltaic cell that photovoltaic cell exports, and as target voltage, then export to the difference determination dutycycle of the voltage of input impedance variable device and target voltage according to photovoltaic cell and generate and adjust drive singal, for adjusting the input impedance of input impedance variable device, the voltage making photovoltaic cell export to input impedance variable device is target voltage, thus no matter whether photovoltaic cell changed in the intensity of illumination received, its voltage outputting to input impedance variable device can both maintain target voltage, avoid existing control circuit owing to following the tracks of the peak power output of photovoltaic cell, thus at the intensity of illumination generation flip-flop that photovoltaic cell receives, namely when the peak power output of photovoltaic cell changes suddenly, because power tracking speed is slow, there is the problem of shaking in the voltage causing photovoltaic cell to export, and avoid the intensity of illumination received when photovoltaic cell and reduce suddenly, namely when the peak power output of photovoltaic cell reduces suddenly, because power tracking speed is slow, the output voltage of photovoltaic cell is caused to be less than the under-voltage shutdown voltage of control circuit, thus the problem causing control circuit to shut down.

Accompanying drawing explanation

Fig. 1 is the schematic diagram of the output voltage of photovoltaic cell and the relation of output current in prior art;

The schematic diagram of the solar power system framework that Fig. 2 provides for the embodiment of the present invention;

One of process flow diagram of the control method that Fig. 3 provides for the embodiment of the present invention;

The process flow diagram two of the control method that Fig. 4 provides for the embodiment of the present invention;

The process flow diagram three of the control method that Fig. 5 provides for the embodiment of the present invention;

The process flow diagram four of the control method that Fig. 6 provides for the embodiment of the present invention;

The process flow diagram five of the control method that Fig. 7 provides for the embodiment of the present invention;

The structural representation of the control device that Fig. 8 provides for the embodiment of the present invention;

The schematic diagram of one of the structure of the control circuit that Fig. 9 provides for the embodiment of the present invention;

The schematic diagram of the structure two of the control circuit that Figure 10 provides for the embodiment of the present invention;

The schematic diagram of the structure three of the control circuit that Figure 11 provides for the embodiment of the present invention;

The schematic diagram of the structure four of the control circuit that Figure 12 provides for the embodiment of the present invention;

The schematic diagram of the gain of input impedance variable device and the relation between amplification and the voltage difference after compensating when input impedance variable device in the control circuit that Figure 13 provides for the embodiment of the present invention only comprises step-up DC/DC transducer;

The schematic diagram of the gain of input impedance variable device and the relation between amplification and the voltage difference after compensating when input impedance variable device in the control circuit that Figure 14 provides for the embodiment of the present invention only comprises voltage-dropping type dcdc converter;

The schematic diagram of the gain of input impedance variable device and the relation between amplification and the voltage difference after compensating when input impedance variable device in the control circuit that Figure 15 provides for the embodiment of the present invention comprises voltage-dropping type dcdc converter and voltage-dropping type dcdc converter;

The schematic diagram of the structure five of the control circuit that Figure 16 provides for the embodiment of the present invention;

The schematic diagram of the structure six of the control circuit that Figure 17 provides for the embodiment of the present invention;

The schematic diagram of the structure seven of the control circuit that Figure 18 provides for the embodiment of the present invention;

The schematic diagram of the structure eight of the control circuit that Figure 19 a provides for the embodiment of the present invention;

The schematic diagram of the structure nine of the control circuit that Figure 19 b provides for the embodiment of the present invention;

The schematic diagram of the structure ten of the control circuit that Figure 20 a provides for the embodiment of the present invention;

The structure of the control circuit that Figure 20 b provides for the embodiment of the present invention 11 schematic diagram;

The structure of the control circuit that Figure 21 a provides for the embodiment of the present invention 12 schematic diagram;

The structure of the control circuit that Figure 21 b provides for the embodiment of the present invention 13 schematic diagram.

Embodiment

Embodiments provide a kind of control method, device and circuit and electricity generation system, the voltage of maximum power point is operated in by obtaining photovoltaic cell, and as target voltage, and according to the real-time voltage of photovoltaic cell output and the difference of target voltage, determine dutycycle, and generate adjustment drive singal according to the dutycycle determined, to adjust the input impedance of input impedance variable device, the voltage making photovoltaic cell output to this input impedance variable device maintains target voltage, avoid the existing control circuit comprising input impedance variable device, when the intensity of illumination generation flip-flop that photovoltaic cell receives, there is the problem of shaking in the voltage that photovoltaic cell can be made to export, and avoid when the intensity of illumination that photovoltaic cell receives reduces suddenly, the problem of shutdown that the control circuit that may cause is under-voltage.

When external environment changes, as temperature, intensity of illumination etc. change time, the family curve of photovoltaic cell output current and output voltage can change, the family curve of output power and output voltage can change, in order to obtain maximum output power, propose the method that some follow the tracks of peak power in prior art, can maximum power point be operated in make photovoltaic cell.But during owing to following the tracks of power, tracking velocity is slow, and when intensity of illumination changes suddenly, the output power of photovoltaic cell and the family curve of output voltage change suddenly, the method of existing tracking power cannot make photovoltaic cell get back to rapidly maximum power point work, and this can make the output voltage of photovoltaic cell change rapidly, if intensity of illumination reduces suddenly a lot, the output voltage of photovoltaic cell may be less than the under-voltage shutdown voltage of control circuit, causes control circuit to shut down.

Due to intensity of illumination change time, although the output power of photovoltaic cell and the family curve of output voltage can change, but, the voltage of the maximum power point of photovoltaic cell is substantially constant, therefore, the invention provides a kind of control method, device and circuit and electricity generation system, voltage when being operated in maximum power point by obtaining photovoltaic cell as target voltage, then the voltage exported in real time according to photovoltaic cell and the difference of target voltage adjust the input impedance of input impedance variable device, make the real-time output voltage of photovoltaic cell can tracking target voltage rapidly, when undergoing mutation to avoid intensity of illumination, the voltage that photovoltaic cell exports can shake, even cause the control circuit shutdown comprising input impedance variable device.

The mechanism of solar power system as shown in Figure 2, comprise photovoltaic cell 21, input impedance variable device 22, successive load 23 and control circuit 24, input impedance variable device 22 connects photovoltaic cell 21 and successive load 23 respectively, if input impedance variable device 22 exports direct current signal, then can comprise accumulator in successive load 23 with store electrical energy; If input impedance variable device 22 output AC signal, then successive load 23 only can comprise consumer, and control circuit 24, by regulating the input impedance of input impedance variable device 22, changes output voltage and the output power of photovoltaic cell 21.

Below in conjunction with Figure of description, a kind of control method, device and the circuit that provide the embodiment of the present invention and the embodiment of electricity generation systems are described.

A kind of control method that the embodiment of the present invention provides, as shown in Figure 3, comprising:

S301, output to the voltage and current of input impedance variable device according to photovoltaic cell, obtain the maximum power point voltage of photovoltaic cell, and as target voltage;

S302, output to the voltage of input impedance variable device and the voltage difference of target voltage according to photovoltaic cell, determine dutycycle;

S303, generate adjustment drive singal according to the dutycycle determined, for adjusting the input impedance of input impedance variable device.

Wherein, input impedance variable device can be DC-to-dc dcdc converter.In S301, along with the change of external environment, the output power of photovoltaic cell and the family curve of output voltage are constantly changing, and therefore, target voltage also can change thereupon.

Further, when input impedance variable device comprises the first DC-to-dc dcdc converter, as shown in Figure 4, S302 and S303 specifically comprises:

The voltage difference of S30201, voltage photovoltaic cell being outputted to input impedance variable device and target voltage carries out amplifying and compensating;

Voltage difference after S30202, judgement amplification and compensation and the relation of the first preset range;

If S30203 amplification and the voltage difference after compensating are in the first preset range, then determine the first dutycycle according to amplification and the voltage difference after compensating;

If S30204 amplification and the voltage difference after compensating are not more than the minimum value of the first preset range, determine that the first dutycycle is the acceptable minimum duty cycle of the first dcdc converter;

If S30205 amplification and the voltage difference after compensating are not less than the maximal value of the first preset range, determine that the first dutycycle is the acceptable maximum duty cycle of the first dcdc converter;

S3031, according to determine first dutycycle generate first adjustment drive singal, for adjusting the input impedance of the first dcdc converter.

When voltage difference after amplification and compensation is within the first preset range, according to the voltage difference determination dutycycle of amplifying and after compensation, can linear relationship be adopted, the voltage difference after amplification and compensation is converted to the first dutycycle.When the voltage difference of the input voltage that the first dcdc converter receives and target voltage is within the first preset range after amplifying and compensating, the voltage that the first dcdc converter makes photovoltaic cell output to the first dcdc converter by the input impedance changing self can be controlled and equal target voltage.

When the first dcdc converter is step-up DC/DC transducer, if when the voltage that photovoltaic cell outputs to input impedance variable device is less than target voltage, first dcdc converter needs the input impedance increasing self, to increase the voltage self received, due to, step-up DC/DC transducer is when the dutycycle of the first adjustment drive singal received increases, the input impedance of self can reduce, therefore, need the first dutycycle that generation one is less, to increase the input impedance of the first dcdc converter, thus increase the voltage that photovoltaic cell outputs to the first dcdc converter, if when the voltage that photovoltaic cell outputs to input impedance variable device is greater than target voltage, first dcdc converter needs the input impedance reducing self, to reduce the voltage self received, due to, step-up DC/DC transducer is when the dutycycle of the first adjustment drive singal received increases, the input impedance of self can reduce, therefore, need the first dutycycle that generation one is larger, to reduce the input impedance of the first dcdc converter, thus reduce the voltage that photovoltaic cell outputs to input impedance variable device.

Due to boost converter receive first adjustment drive singal dutycycle between its acceptable minimum duty cycle and its acceptable maximum duty cycle time, the dutycycle of the first adjustment drive singal received is larger, gain is larger, and the ratio of the signal that the signal that namely boost converter exports receives with it is larger; When the dutycycle of the first adjustment drive singal that boost converter receives is for its acceptable minimum duty cycle, gain is 1; When the dutycycle of the first adjustment drive singal that boost converter receives is for its acceptable maximum duty cycle, gain is infinitely great.

When the first dcdc converter is voltage-dropping type dcdc converter, if when the voltage that photovoltaic cell outputs to input impedance variable device is less than target voltage, first dcdc converter needs the input impedance increasing self, to increase the voltage self received, due to, voltage-dropping type dcdc converter is when the dutycycle of the first adjustment drive singal received increases, the input impedance of self can reduce, therefore, need the first dutycycle that generation one is less, to increase the input impedance of the first dcdc converter, thus improve the voltage that photovoltaic cell outputs to input impedance variable device, if when the voltage that photovoltaic cell outputs to input impedance variable device is greater than target voltage, first dcdc converter needs the input impedance reducing self, to reduce the voltage self received, due to, voltage-dropping type dcdc converter is when the dutycycle of the first adjustment drive singal received increases, the input impedance of self can reduce, therefore, need the first dutycycle that generation one is larger, to reduce the input impedance of the first dcdc converter, thus reduce the voltage that photovoltaic cell outputs to input impedance variable device.

Due to buck convertor receive first adjustment drive singal dutycycle between its acceptable minimum duty cycle and its acceptable maximum duty cycle time, the dutycycle of the first adjustment drive singal received is less, gain is less, and the ratio of the signal that the signal that namely buck convertor exports receives with it is less; When the dutycycle of the first adjustment drive singal that buck convertor receives is for its acceptable maximum duty cycle, gain is 1; When the dutycycle of the first adjustment drive singal that buck convertor receives is for its acceptable minimum duty cycle, gain is 0.

Further, as shown in Figure 5, when input impedance variable device also comprises the second dcdc converter be connected with the first DC-to-dc dcdc converter, S302 and S303 also comprises:

S30206, determine amplify and compensate after voltage difference and bias voltage voltage and; Bias voltage the first dcdc converter be step-up DC/DC transducer, the second dcdc converter equals the difference of the maximal value of the second preset range and the minimum value of the first preset range when being voltage-dropping type dcdc converter, the first dcdc converter be voltage-dropping type dcdc converter, the second dcdc converter equals the difference of the minimum value of the second preset range and the maximal value of the first preset range when being step-up DC/DC transducer;

S30207, judge the voltage determined and the relation with the second preset range;

If the voltage that S30208 determines and in the second preset range, according to the voltage determined with determine the second dutycycle;

If the voltage that S30209 determines and when being not more than the minimum value of the second preset range, then determine that the second dutycycle is the acceptable minimum duty cycle of the second dcdc converter;

If the voltage that S30210 determines and when being not less than the maximal value of the second preset range, then determine that the second dutycycle is the acceptable maximum duty cycle of the second dcdc converter;

S3032, according to determine second dutycycle generate second adjustment drive singal, for adjusting the input impedance of the second dcdc converter.

Wherein, S30202-S30205 and S30206-S30210 does not have the precedence relationship in sequential, first can perform S30202-S30205, rear execution S30206-S30210; Also first S30206-S30210 can be performed, rear execution S30202-S30205; S30202-S30205 and S30206-S30210 can also be performed simultaneously.In addition, S3031 and S3032 does not have the sequencing in sequential yet, first can perform S3031, rear execution S3032; Also first S3032 can be performed, rear execution S3031; S3031 and S3032 can also be performed simultaneously.

Time at the voltage determined and within the second preset range, according to the voltage determined with determine dutycycle, linear relationship can be adopted, by the voltage determined be converted to the second dutycycle.Time when the voltage determined and within the second preset range, the voltage that the second dcdc converter makes photovoltaic cell output to input impedance variable device by the input impedance changing self can be controlled and equal target voltage.

When the first dcdc converter is step-up DC/DC transducer, when second dcdc converter is voltage-dropping type dcdc converter, if the voltage difference of the input voltage that input impedance variable device receives and target voltage after amplifying and compensating within the first preset range time, according to the voltage difference determination dutycycle of amplifying and after compensation, linear relationship can be adopted, amplification and the voltage difference after compensating are converted to the first dutycycle and determine the first adjustment drive singal, thus control the input impedance of the first dcdc converter adjustment self, the voltage making photovoltaic cell output to input impedance variable device is target voltage, if the voltage difference of the input voltage that input impedance variable device receives and target voltage is not more than the minimum value of the first preset range after amplifying and compensating, the first dutycycle then determined is the acceptable minimum duty cycle of the first dcdc converter, therefore, the gain of the first dcdc converter is 1, now, if the voltage difference of the input voltage that input impedance variable device receives and target voltage continues to reduce, the first dutycycle then determined still is the acceptable minimum duty cycle of the first dcdc converter, therefore, the gain of the first dcdc converter is still 1, that is the first dcdc converter can not carry out tracking target voltage by the input impedance adjusting self again.

But when also comprising the second dcdc converter in input impedance variable device, if the voltage difference of the input voltage that input impedance variable device receives and target voltage equals the minimum value of the first preset range after amplifying and compensating, the first dutycycle determined is the acceptable minimum duty cycle of the first dcdc converter, and the gain of the first dcdc converter is 1, due to bias voltage the first dcdc converter be step-up DC/DC transducer, the second dcdc converter equals the difference of the maximal value of the second preset range and the minimum value of the first preset range when being voltage-dropping type dcdc converter, therefore, now amplify and voltage difference after compensating and bias voltage voltage and equal the maximal value of the second preset range, the second dutycycle determined is the acceptable maximum duty cycle of the second dcdc converter, and the gain of the second dcdc converter is 1, when the voltage difference of the input voltage that the first dcdc converter receives and target voltage reduces further, although, first dcdc converter can not carry out tracking target voltage by the input impedance adjusting self again, but, to amplify and voltage difference after compensating and bias voltage sum can become from the maximal value equaling the second preset range and be within the second preset range, that is the second dutycycle can from the acceptable maximum duty cycle of the second dcdc converter, become and be less than the acceptable maximum duty cycle of the second dcdc converter, the gain of the second dcdc converter is less than 1 for being reduced to from 1.

The voltage difference of the input voltage that the second dcdc converter receives and target voltage after amplifying and compensating with the voltage of bias voltage be within the second preset range, then the voltage difference of the input voltage that receives of the first dcdc converter and target voltage is less than the minimum value of the first preset range after amplifying and compensating, now, the gain of the first dcdc converter is 1, the input impedance of the second dcdc converter can be adjusted by the dutycycle adjusting the second adjustment drive singal, thus change the input impedance of input impedance variable device, adjustment photovoltaic cell outputs to the voltage of input impedance variable device, the increase of the input voltage received along with the first dcdc converter and the voltage difference of target voltage, the voltage difference of the input voltage that the first dcdc converter receives and target voltage after amplifying and compensating with the voltage of bias voltage with also can increase, when voltage with when being not less than the maximal value of the second preset range, the voltage difference of the input voltage that the first dcdc converter receives and target voltage is not less than the minimum value of the first preset range after amplifying and compensating, now, the gain of the second dcdc converter is 1, the input impedance of the first dcdc converter can be adjusted by the dutycycle adjusting the first adjustment drive singal, thus change the input impedance of input impedance variable device, adjustment photovoltaic cell outputs to the voltage of input impedance variable device.

When the first dcdc converter is voltage-dropping type dcdc converter, when second dcdc converter is step-up DC/DC transducer, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage after amplifying and compensating within the first preset range time, according to the voltage difference determination dutycycle of amplifying and after compensation, linear relationship can be adopted, amplification and the voltage difference after compensating are converted to dutycycle and determine the first adjustment drive singal according to dutycycle, thus control the input impedance of the first dcdc converter adjustment self, the voltage making photovoltaic cell output to input impedance variable device is target voltage, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage is not less than the maximal value of the first preset range after amplifying and compensating, the first dutycycle then determined is the acceptable maximum duty cycle of the first dcdc converter, therefore, the gain of the first dcdc converter is 1, now, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage continues to increase, the first dutycycle then determined still is the acceptable maximum duty cycle of the first dcdc converter, therefore, the gain of the first dcdc converter is still 1, that is the first dcdc converter can not carry out tracking target voltage by the input impedance adjusting self again.

But owing to also comprising the second dcdc converter in input impedance variable device, the input voltage received when the first dcdc converter and the voltage difference of target voltage equal the maximal value of the first preset range after amplifying and compensating, the first dutycycle determined is the acceptable maximum duty cycle of the first dcdc converter, and the gain of the first dcdc converter is 1, due to bias voltage the first dcdc converter be voltage-dropping type dcdc converter, the second dcdc converter equals the difference of the minimum value of the second preset range and the maximal value of the first preset range when being step-up DC/DC transducer, therefore, now determine the voltage of the voltage difference after amplifying and compensating and bias voltage and equal the minimum value of the second preset range, now, the second dutycycle determined is the acceptable minimum duty cycle of the second dcdc converter, and the gain of the second dcdc converter is 1, when the voltage difference of the input voltage that the first dcdc converter receives and target voltage increases further, although, first dcdc converter can not carry out tracking target voltage by the input impedance adjusting self again, but, amplify and compensate after voltage difference and bias voltage sum can become from the minimum value equaling the second preset range, be within the second preset range, that is the second dutycycle can from the acceptable minimum duty cycle of the second dcdc converter, become and be greater than the acceptable minimum duty cycle of the second dcdc converter, the gain of the second dcdc converter is greater than 1 for increasing to from 1.

When the value of voltage difference after amplifying and compensating of the input voltage that the first dcdc converter receives and target voltage increases gradually from the maximal value of the first preset range, the voltage difference of the input voltage that the first dcdc converter receives and target voltage after amplifying and compensating with the voltage of bias voltage with can increase gradually from the minimum value of the second preset range, now, the gain of the first dcdc converter is 1, the input impedance of the second dcdc converter can be adjusted by the dutycycle adjusting the second adjustment drive singal, thus change the input impedance of input impedance variable device, adjustment photovoltaic cell outputs to the voltage of input impedance variable device, the input voltage received along with the first dcdc converter and the voltage difference of target voltage reduce, the voltage difference of the input voltage that the first dcdc converter receives and target voltage after amplifying and compensating with the voltage of bias voltage with also can reduce, when the voltage difference of the input voltage that the first dcdc converter receives and target voltage is not more than the maximal value of the first preset range, voltage and the minimum value being less than the second preset range of amplification and the voltage difference after compensating and bias voltage, now, the gain of the second dcdc converter is 1, the input impedance of the first dcdc converter can be adjusted by the dutycycle adjusting the first adjustment drive singal, thus change the input impedance of input impedance variable device, adjustment photovoltaic cell outputs to the voltage of input impedance variable device.

Further, as shown in Figure 6, when input impedance variable device comprises the first dcdc converter, the control method that the embodiment of the present invention provides also comprises:

S601, judge whether the power needed for the successive load that input impedance variable device connects is not less than the peak power of photovoltaic cell, if so, performs S602; Otherwise, perform S603;

S602, determine that the 3rd dutycycle is the acceptable maximum duty cycle of the first dcdc converter;

S603, determine the dutycycle of the 3rd dutycycle for photovoltaic cell can be made to export the voltage of the power needed for described successive load.

Now, S3031 specifically comprises: generating dutycycle is that first of dutycycle minimum in the first dutycycle and the 3rd dutycycle adjusts drive singal, for adjusting the input impedance of the first dcdc converter.

When the power needed for the successive load that input impedance variable device connects is less than the peak power of photovoltaic cell, the input impedance that the first dcdc converter changes self can be controlled, the output power from photovoltaic cells is made to be less than the peak power of photovoltaic cell, the output voltage simultaneously controlling photovoltaic cell is greater than its maximum power point voltage, that is, the dutycycle of drive singal when dutycycle is less than photovoltaic cell Maximum Power Output point voltage can be generated, and generating corresponding first adjustment drive singal, the input impedance of control inputs impedance variable device increases.Therefore, when the power needed for the successive load that input impedance variable device connects is less than the peak power of photovoltaic cell, minimum dutycycle is determined from the first dutycycle received and the 3rd dutycycle, and generate the first adjustment drive singal export to the first dcdc converter that dutycycle is the minimum dutycycle determined, the input impedance of input impedance variable device is increased, thus the voltage making photovoltaic cell export to input impedance variable device increase, power reduction.

Further, as shown in Figure 7, when input impedance variable device comprises the first dcdc converter and the second dcdc converter, the control method that the embodiment of the present invention provides also comprises:

S701, judge whether the power needed for the successive load that input impedance variable device connects is not less than the peak power of photovoltaic cell, if so, performs S702; Otherwise, perform S703;

S702, determine that the 4th dutycycle is the acceptable maximum duty cycle of the first dcdc converter, and determine that the 5th dutycycle is the acceptable maximum duty cycle of the second dcdc converter;

S703, determine that the 4th dutycycle and the 5th dutycycle are the dutycycle that photovoltaic cell can be made to export the voltage of the power needed for described successive load.

Now, S3031 specifically comprises: generating dutycycle is that first of dutycycle minimum in the first dutycycle and the 4th dutycycle adjusts drive singal, for adjusting the input impedance of the first dcdc converter; S3032 specifically comprises: generating dutycycle is that second of dutycycle minimum in the second dutycycle and the 5th dutycycle adjusts drive singal, for adjusting the input impedance of the second dcdc converter.

When the power needed for the successive load that input impedance variable device connects is less than the peak power of photovoltaic cell, the input impedance of the first dcdc converter can be changed, or change the input impedance of the second dcdc converter, the output power from photovoltaic cells is made to be less than the peak power of photovoltaic cell, the output voltage simultaneously controlling photovoltaic cell is greater than its maximum power point voltage, that is, the dutycycle of drive singal when dutycycle is less than photovoltaic cell Maximum Power Output point voltage can be generated, and generate corresponding first adjustment drive singal and the second adjustment drive singal, the input impedance of control inputs impedance variable device increases.Therefore, when the power needed for the successive load that input impedance variable device connects is less than the peak power of photovoltaic cell, minimum dutycycle can be determined from the first dutycycle received and the 4th dutycycle, and generate the first adjustment drive singal export to the first dcdc converter that dutycycle is the minimum dutycycle determined, and minimum dutycycle can be determined from the second dutycycle received and the 5th dutycycle, and generate the second adjustment drive singal export to the second dcdc converter that dutycycle is the minimum dutycycle determined, the input impedance of input impedance variable device is increased, thus the voltage making photovoltaic cell export to input impedance variable device increases, power reduction.If the dutycycle of the first adjustment drive singal is the 4th dutycycle, so the first dcdc converter changes the input impedance of self, thus the input impedance of input impedance variable device is increased; If the dutycycle of the second adjustment signal is the 5th dutycycle, so the second dcdc converter changes the input impedance of self, thus the input impedance of input impedance variable device is increased.

When input impedance variable device comprises inverter, the control method that the embodiment of the present invention provides no longer judges the relation of the peak power of power needed for the load that input impedance variable device connects and photovoltaic cell, namely no longer comprises the step shown in Fig. 6 and Fig. 7.Now, the inverter in input impedance variable device is connected with successive load.

Further, when input impedance variable device comprises inverter, the control method that the embodiment of the present invention provides also comprises: the voltage and current determination inversion drive singal exported according to inverter, changes the direct current signal received into AC signal for controlling this inverter.If input impedance variable device comprises the first dcdc converter and inverter, then the direct current signal received from the first dcdc converter is converted to AC signal by inverter.If input impedance variable device comprises the first dcdc converter, the second dcdc converter and inverter, then the direct current signal received from the second dcdc converter is converted to AC signal by inverter.

Based on same inventive concept, the embodiment of the present invention additionally provides a kind of control device and control circuit, the principle of dealing with problems due to control device and control circuit is similar to aforementioned control method, therefore the enforcement of this device and circuit see the enforcement of preceding method, can repeat part and repeats no more.

A kind of control device that the embodiment of the present invention provides, as shown in Figure 8, comprising:

Acquisition module 81, for outputting to the voltage and current of input impedance variable device according to photovoltaic cell, obtains the maximum power point voltage of photovoltaic cell, and as target voltage;

Determination module 82, for outputting to the voltage of input impedance variable device and the voltage difference of target voltage according to photovoltaic cell, determines dutycycle;

Generation module 83, for generating adjustment drive singal according to the dutycycle determined, for adjusting the input impedance of input impedance variable device.

Further, determination module 82 specifically for: when input impedance variable device comprises the first DC-to-dc dcdc converter, the voltage difference of the voltage and target voltage that photovoltaic cell are outputted to input impedance variable device carries out amplifying and compensating; If amplification and the voltage difference after compensating in the first preset range, then determine the first dutycycle according to described voltage difference; If amplification and the voltage difference after compensating are not more than the minimum value of the first preset range, determine that the first dutycycle is the acceptable minimum duty cycle of the first dcdc converter; If amplification and the voltage difference after compensating are not less than the maximal value of the first preset range, determine that the first dutycycle is the acceptable maximum duty cycle of the first dcdc converter;

Generation module 83 specifically for: according to determine first dutycycle generate first adjustment drive singal, for adjusting the input impedance of the first dcdc converter.

Preferably, determination module 82 also for: when described input impedance variable device also comprises the second dcdc converter be connected with the first DC-to-dc dcdc converter, determine the voltage of voltage difference and bias voltage after amplifying and compensating with; If the voltage determined and in the second preset range, according to the voltage determined with determine the second dutycycle; If the voltage determined and when being not more than the minimum value of the second preset range, then determine that the second dutycycle is the acceptable minimum duty cycle of the second dcdc converter; If the voltage determined and when being not less than the maximal value of the second preset range, then determine that the second dutycycle is the acceptable maximum duty cycle of the second dcdc converter; Described bias voltage the first dcdc converter be step-up DC/DC transducer, the second dcdc converter equals the difference of the maximal value of the second preset range and the minimum value of the first preset range when being voltage-dropping type dcdc converter, the first dcdc converter be voltage-dropping type dcdc converter, the second dcdc converter equals the difference of the minimum value of the second preset range and the maximal value of the first preset range when being step-up DC/DC transducer;

Generation module 83 also for: according to determine second dutycycle generate second adjustment drive singal, for adjusting the input impedance of the second dcdc converter.

Further, determination module 82 also for: input impedance variable device connect successive load needed for power be not less than the peak power of photovoltaic cell time, determine that the 3rd dutycycle is the acceptable maximum duty cycle of the first dcdc converter; When the power needed for the successive load that described input impedance variable device connects is less than the peak power of photovoltaic cell, determine the dutycycle of the 3rd dutycycle for photovoltaic cell can be made to export the voltage of the power needed for described successive load;

Generation module 83 specifically for: generating dutycycle is that first of dutycycle minimum in the first dutycycle and the 3rd dutycycle adjusts drive singal, for adjusting the input impedance of the first dcdc converter.

Further, determination module 82 also for: when the power needed for the successive load that described input impedance variable device connects is not less than the peak power of photovoltaic cell, determine that the 4th dutycycle is the acceptable maximum duty cycle of the first dcdc converter, determine that the 5th dutycycle is the acceptable maximum duty cycle of the second dcdc converter; When the power needed for the successive load that described input impedance variable device connects is less than the peak power of photovoltaic cell, determine that the 4th dutycycle and the 5th dutycycle are the dutycycle that photovoltaic cell can be made to export the voltage of the power needed for described successive load;

Generation module 83 specifically for: generating dutycycle is that first of dutycycle minimum in the first dutycycle and the 4th dutycycle adjusts drive singal, for adjusting the input impedance of the second dcdc converter; And to generate dutycycle be that second of dutycycle minimum in the second dutycycle and the 5th dutycycle adjusts drive singal, for adjusting the input impedance of the second dcdc converter.

A kind of control circuit that the embodiment of the present invention provides, as shown in Figure 9, comprises input voltage control module 91, drives logical block 92 and MPPT maximum power point tracking MPPT unit 93; Logical block 92 is driven to connect input voltage control module 91 and input impedance variable device 22 respectively; MPPT unit 93 connects input impedance variable device 22 and input voltage control module 91 respectively; MPPT unit 93, for outputting to the voltage and current of input impedance variable device 22 according to photovoltaic cell 21, obtains the maximum power point voltage of photovoltaic cell 21, and exports to input voltage control module 91 as target voltage; Input voltage control module 91, for the difference determination dutycycle of the voltage and target voltage that output to input impedance variable device 22 according to photovoltaic cell 21, and exports to and drives logical block 92; Driving logical block 92, for generating adjustment drive singal according to the dutycycle received, and exporting to described input impedance variable device 22, for adjusting the input impedance of input impedance variable device 22.Wherein, input impedance variable device 33 can comprise DC-to-dc dcdc converter.

Wherein MPPT unit can follow the tracks of voltage when photovoltaic cell is operated in maximum power point in any number of ways.

Due to the intensity of illumination received at photovoltaic cell change suddenly time, the output power-output voltage PV curve of photovoltaic cell can change, but intensity of illumination change before and after, the voltage of the maximum power point in the PV curve of photovoltaic cell is but substantially constant.Now, MPPT unit in control circuit can follow the tracks of the voltage of the maximum power point of photovoltaic cell, but, because this voltage remains unchanged substantially, therefore, the target voltage that MPPT module exports to input voltage control module also remains unchanged substantially, by the tracking of input voltage control module to photovoltaic cell output voltage, makes photovoltaic cell also can be operated in maximum power point.Therefore, when not having MPPT module in control circuit, control circuit can make photovoltaic cell be operated in maximum power point under different photoenvironments.

When environment temperature around photovoltaic cell changes, the output power-output voltage PV curve of photovoltaic cell can change, and the voltage of maximum power point in the PV curve of photovoltaic cell also can change.Now, MPPT unit in control circuit can follow the tracks of the voltage of the maximum power point of photovoltaic cell, constantly change the target voltage exporting to input voltage control module, by the tracking of input voltage control module to photovoltaic cell output voltage, make photovoltaic cell also can be operated in maximum power point.Therefore, when having MPPT unit in control circuit, control circuit can, under different photoenvironments, make photovoltaic cell be operated in maximum power point under different temperature environments.

Further, as shown in Figure 10, input impedance variable device 22 in the control circuit that the embodiment of the present invention provides comprises the first DC-to-dc dcdc converter 221, and input voltage control module 91 comprises voltage control circuit 911, drives logical block 92 to comprise the first driving logic circuit 921;

Voltage control circuit 911, for determining that photovoltaic cell 21 outputs to the voltage of the first dcdc converter 221 and the voltage difference of target voltage, and amplifies the voltage difference determined and compensates; And amplify and compensate after voltage difference within the first preset range time, the first dutycycle is determined according to amplification and the voltage difference after compensating, when voltage difference after amplifying and compensating is not more than the minimum value of the first preset range, determine that the first dutycycle is the acceptable minimum duty cycle of the first dcdc converter 221, when voltage difference after amplifying and compensating is not less than the maximal value of the first preset range, determine that the first dutycycle is the acceptable maximum duty cycle of the first dcdc converter 221, and the first dutycycle determined is exported to the first driving logic circuit 921;

First driving logic circuit 921, for generating the first adjustment drive singal and exporting to the first dcdc converter 221 according to the first dutycycle received.

When voltage difference after amplification and compensation is within the first preset range, determines the first dutycycle according to amplification and the voltage difference after compensating, can linear relationship be adopted, the voltage difference after amplification and compensation is converted to the first dutycycle.When the voltage difference of the input voltage that the first dcdc converter receives and target voltage is within the first preset range after amplifying and compensating, voltage control circuit and the first driving logic circuit can control the voltage that the first dcdc converter makes photovoltaic cell output to the first dcdc converter by the input impedance changing self and equal target voltage.

When the first dcdc converter is step-up DC/DC transducer, if when the voltage that photovoltaic cell outputs to the first dcdc converter is less than target voltage, first dcdc converter needs the input impedance increasing self, to increase the voltage self received, due to, step-up DC/DC transducer is when the dutycycle of the first adjustment drive singal received increases, the input impedance of self can reduce, therefore, the first dutycycle that voltage control circuit needs generation one less, to increase the input impedance of the first dcdc converter, thus increase the voltage that photovoltaic cell outputs to the first dcdc converter, if when the voltage that photovoltaic cell outputs to the first dcdc converter is greater than target voltage, first dcdc converter needs the input impedance reducing self, to reduce the voltage self received, due to, step-up DC/DC transducer is when the dutycycle of the first adjustment drive singal received increases, the input impedance of self can reduce, therefore, voltage control circuit needs the first dutycycle that generation one is larger, to reduce the input impedance of the first dcdc converter, thus reduce the voltage that photovoltaic cell outputs to the first dcdc converter.

When the first dcdc converter is voltage-dropping type dcdc converter, if when the voltage that photovoltaic cell outputs to the first dcdc converter is less than target voltage, first dcdc converter needs the input impedance increasing self, to increase the voltage self received, due to, voltage-dropping type dcdc converter is when the dutycycle of the first adjustment drive singal received increases, the input impedance of self can reduce, therefore, the first dutycycle that voltage control circuit needs generation one less, to increase the input impedance of the first dcdc converter, thus improve the voltage that photovoltaic cell outputs to the first dcdc converter, if when the voltage that photovoltaic cell outputs to the first dcdc converter is greater than target voltage, first dcdc converter needs the input impedance reducing self, to reduce the voltage self received, due to, voltage-dropping type dcdc converter is when the dutycycle of the first adjustment drive singal received increases, the input impedance of self can reduce, therefore, voltage control circuit needs the first dutycycle that generation one is larger, to reduce the input impedance of the first dcdc converter, thus reduce the voltage that photovoltaic cell outputs to the first dcdc converter.

Due to buck convertor receive first adjustment drive singal dutycycle between its acceptable minimum duty cycle and its acceptable maximum duty cycle time, the dutycycle more effect of the first adjustment drive singal received, gain is less, and the ratio of the signal that the signal that namely buck convertor exports receives with it is less; When the dutycycle of the first adjustment drive singal that buck convertor receives is for its acceptable maximum duty cycle, gain is 1; When the dutycycle of the first adjustment drive singal that buck convertor receives is for its acceptable minimum duty cycle, gain is 0.

Further, as shown in figure 11, voltage control circuit 911 comprises subtracter 9111, corrective network 9112 and the first pulse width generators 9113;

Subtracter 9111, for determining that photovoltaic cell outputs to the voltage of the first dcdc converter 221 and the voltage difference of target voltage, and exports to corrective network 9112;

Corrective network 9112, for amplifying the voltage difference from subtracter 9111 received and compensating, and exports to the first pulse width generators 9113;

First pulse width generators 9113, for when the voltage difference carrying out SCN self-compensating network 9112 received is within the first preset range, the first dutycycle is determined according to the voltage difference received, when the voltage difference received is not more than the minimum value of the first preset range, determine that the first dutycycle is the acceptable minimum duty cycle of the first dcdc converter, when the voltage difference received is not less than the maximal value of the first preset range, determine that the first dutycycle is the acceptable maximum duty cycle of the first dcdc converter, and the first dutycycle determined is exported to described first driving logic circuit 921.

Wherein, corrective network can adoption rate integral controller or other corrective networks.

Preferably, as shown in figure 12, the input impedance variable device 22 in the control circuit that the embodiment of the present invention provides also comprises the second dcdc converter 222, second dcdc converter 222 and connects the first dcdc converter 221; Input voltage control module 91 also comprises adjustable extent increasing circuit 912, drives logical block 92 also to comprise the second driving logic circuit 922;

Adjustable extent increasing circuit 912, for determine the voltage of the amplification that the voltage control circuit 911 that receives exports and the voltage difference after compensating and bias voltage with; And time at the voltage determined and within the second preset range, according to the voltage determined and determine the second dutycycle, at the voltage determined with when being not more than the minimum value of the second preset range, determine that the second dutycycle is the acceptable minimum duty cycle of the second dcdc converter, at the voltage determined with when being not less than the maximal value of the second preset range, determine that the second dutycycle is the acceptable maximum duty cycle of the second dcdc converter; And the second dutycycle determined is exported to the second driving logic circuit 922; Bias voltage the first dcdc converter be step-up DC/DC transducer, the second dcdc converter equals the difference of the maximal value of the second preset range and the minimum value of the first preset range when being voltage-dropping type dcdc converter, the first dcdc converter be voltage-dropping type dcdc converter, the second dcdc converter equals the difference of the minimum value of the second preset range and the maximal value of the first preset range when being step-up DC/DC transducer;

Second driving logic circuit 922, for generating the second adjustment drive singal and exporting to described second dcdc converter, for adjusting the input impedance of the second dcdc converter according to the second dutycycle received.

Time at the voltage determined and within the second preset range, according to the voltage determined with determine the second dutycycle, linear relationship can be adopted, by the voltage determined be converted to the second dutycycle.Time when the voltage of the amplification that voltage control circuit exports and the voltage difference after compensating and bias voltage and within the second preset range, adjustable extent increasing circuit and the second driving logic circuit can control the voltage that the second dcdc converter makes photovoltaic cell output to input impedance variable device by the input impedance changing self and equal target voltage.

When the first dcdc converter is step-up DC/DC transducer, when second dcdc converter is voltage-dropping type dcdc converter, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage after amplifying and compensating within the first preset range time, the first dutycycle is determined according to amplification and the voltage difference after compensating, linear relationship can be adopted, amplification and the voltage difference after compensating are converted to the first dutycycle and export to the first driving logic circuit, first driving logic circuit determines the first adjustment drive singal according to the first dutycycle received, thus control the input impedance of the first dcdc converter adjustment self, the voltage making photovoltaic cell output to the first dcdc converter is target voltage, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage is not more than the minimum value of the first preset range after amplifying and compensating, the first dutycycle that voltage control circuit is determined is the acceptable minimum duty cycle of the first dcdc converter, therefore, the gain of the first dcdc converter is 1, now, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage continues to reduce, the first dutycycle that voltage control circuit is determined still is the acceptable minimum duty cycle of the first dcdc converter, therefore, the gain of the first dcdc converter is still 1, that is the first dcdc converter can not carry out tracking target voltage by the input impedance adjusting self again.

But owing to also comprising adjustable extent increasing circuit, the second logic drive circuit and the second dcdc converter in control circuit, the input voltage received when the first dcdc converter and the voltage difference of target voltage equal the minimum value of the first preset range after amplifying and compensating, the first dutycycle that voltage control circuit is determined is the acceptable minimum duty cycle of the first dcdc converter, and the gain of the first dcdc converter is 1, because bias voltage is step-up DC/DC transducer at the first dcdc converter, second dcdc converter equals the difference of the maximal value of the second preset range and the minimum value of the first preset range when being voltage-dropping type dcdc converter, therefore, the voltage of the now amplification that exports at the voltage control circuit determining to receive of adjustable extent increasing circuit and the voltage difference after compensating and bias voltage with, equal the maximal value of the second preset range, now, the second dutycycle that adjustable extent increasing circuit is determined is the acceptable maximum duty cycle of the second dcdc converter, the gain of the second dcdc converter is 1, when the voltage difference of the input voltage that the first dcdc converter receives and target voltage reduces further, although, first dcdc converter can not carry out tracking target voltage by the input impedance adjusting self again, but, to amplify and voltage difference after compensating and bias voltage sum can become from the maximal value equaling the second preset range and be within the second preset range, that is the second dutycycle that adjustable extent increasing circuit is determined can from the acceptable maximum duty cycle of the second dcdc converter, become and be less than the acceptable maximum duty cycle of the second dcdc converter, the gain of the second dcdc converter is less than 1 for being reduced to from 1.

When the first dcdc converter is voltage-dropping type dcdc converter, when second dcdc converter is step-up DC/DC transducer, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage after amplifying and compensating within the first preset range time, the first dutycycle is determined according to amplification and the voltage difference after compensating, linear relationship can be adopted, amplification and the voltage difference after compensating are converted to the first dutycycle and export to the first driving logic circuit, first driving logic circuit determines the first adjustment drive singal according to the first dutycycle received, thus control the input impedance of the first dcdc converter adjustment self, the voltage making photovoltaic cell output to the first dcdc converter is target voltage, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage is not less than the maximal value of the first preset range after amplifying and compensating, the first dutycycle that voltage control circuit is determined is the acceptable maximum duty cycle of the first dcdc converter, therefore, the gain of the first dcdc converter is 1, now, if the voltage difference of the input voltage that the first dcdc converter receives and target voltage continues to increase, the first dutycycle that voltage control circuit is determined still is the acceptable maximum duty cycle of the first dcdc converter, therefore, the gain of the first dcdc converter is still 1, that is the first dcdc converter can not carry out tracking target voltage by the input impedance adjusting self again.

But owing to also comprising adjustable extent increasing circuit, the second logic drive circuit and the second dcdc converter in control circuit, the input voltage received when the first dcdc converter and the voltage difference of target voltage equal the maximal value of the first preset range after amplifying and compensating, the first dutycycle that voltage control circuit is determined is the acceptable maximum duty cycle of the first dcdc converter, and the gain of the first dcdc converter is 1, because bias voltage is voltage-dropping type dcdc converter at the first dcdc converter, second dcdc converter equals the difference of the minimum value of the second preset range and the maximal value of the first preset range when being step-up DC/DC transducer, therefore, the voltage of the now amplification that exports at the voltage control circuit determining to receive of adjustable extent increasing circuit and the voltage difference after compensating and bias voltage with, equal the minimum value of the second preset range, now, the second dutycycle that adjustable extent increasing circuit is determined is the acceptable minimum duty cycle of the second dcdc converter, the gain of the second dcdc converter is 1, when the voltage difference of the input voltage that the first dcdc converter receives and target voltage increases further, although, first dcdc converter can not carry out tracking target voltage by the input impedance adjusting self again, but, amplify and compensate after voltage difference and bias voltage sum can become from the minimum value equaling the second preset range, be within the second preset range, that is the second dutycycle that adjustable extent increasing circuit is determined can from the acceptable minimum duty cycle of the second dcdc converter, become and be greater than the acceptable minimum duty cycle of the second dcdc converter, the gain of the second dcdc converter is greater than 1 for increasing to from 1.

When the value of voltage difference after amplifying and compensating of the input voltage that the first dcdc converter receives and target voltage increases gradually from the maximal value of the first preset range, the voltage difference of the input voltage that the first dcdc converter receives and target voltage after amplifying and compensating with the voltage of bias voltage with can increase gradually from the minimum value of the second preset range, now, the gain of the first dcdc converter is 1, the input impedance of the second dcdc converter can be adjusted by the dutycycle adjusting the second adjustment drive singal, thus change the input impedance of input impedance variable device, adjustment photovoltaic cell outputs to the voltage of input impedance variable device, the input voltage received along with the first dcdc converter and the voltage difference of target voltage reduce, the voltage difference of the input voltage that the first dcdc converter receives and target voltage after amplifying and compensating with the voltage of bias voltage with also can reduce, when the voltage difference of the input voltage that the first dcdc converter receives and target voltage is not more than the maximal value of the first preset range, the voltage of the amplification that the voltage control circuit that what adjustable extent increasing circuit was determined receive exports and the voltage difference after compensating and bias voltage and be less than the minimum value of the second preset range, now, the gain of the second dcdc converter is 1, the input impedance of the first dcdc converter can be adjusted by the dutycycle adjusting the first adjustment drive singal, thus change the input impedance of input impedance variable device, adjustment photovoltaic cell outputs to the voltage of input impedance variable device.

When control circuit comprises the first dcdc converter, the first driving logic circuit, voltage control circuit, if the first dcdc converter is step-up DC/DC transducer, then the relation of the value of voltage difference after amplifying and compensating of the input voltage that receives of the gain of the first dcdc converter and the first dcdc converter and target voltage as shown in figure 13, input impedance variable device, namely the gain of the first dcdc converter can be transferred to infinity from 1; If the first dcdc converter is voltage-dropping type dcdc converter, then the relation of the value of voltage difference after amplifying and compensating of the input voltage that receives of the gain of the first dcdc converter and the first dcdc converter and target voltage as shown in figure 14, input impedance variable device, namely the gain of the first dcdc converter can be transferred to 1 from 0.When control circuit comprises the first dcdc converter, the first driving logic circuit, voltage control circuit, the second dcdc converter, adjustable extent increasing circuit, the second driving logic circuit, as shown in figure 15, the gain of input impedance variable device can be transferred to infinity from 0 to the relation of the value of voltage difference after amplifying and compensating of the input voltage that the gain of input impedance variable device and the first dcdc converter wherein receive and target voltage.Therefore, when both having comprised step-up DC/DC transducer in control circuit, when comprising again voltage-dropping type dcdc converter, control circuit can increase the following range of target voltage.

Adopt two-stage dcdc converter, control circuit can be made to meet the input/output condition of relative broad range, and such as can be together in series by more solar panel forms photovoltaic cell, can meet the successive load of different voltage requirements.

Further, as shown in figure 16, adjustable extent increasing circuit 912 comprises totalizer 9121 and the second pulse width generators 9122;

Totalizer 9121, for determine the voltage of the amplification that the voltage control circuit 911 that receives exports and the voltage difference after compensating and bias voltage with, and be transferred to the second pulse width generators 9122;

Second pulse width generators 9122, for at the voltage from totalizer 9121 received and within the second preset range time, according to the voltage received and determine the second dutycycle, at the voltage received with when being not more than the minimum value of the second preset range, determine that the second dutycycle is the acceptable minimum duty cycle of the second dcdc converter 222, at the voltage received with when being not less than the minimum value of the second preset range, determine that the second dutycycle is the acceptable maximum duty cycle of the second dcdc converter 222; And the second dutycycle determined is exported to the second driving logic circuit 922.

Further, as shown in figure 17, the control circuit that the embodiment of the present invention provides also comprises the first DC-to-dc DCDC control circuit 94;

One DCDC control circuit 94, when being not less than the peak power of photovoltaic cell for the power needed for the successive load that connects at input impedance variable device 22, determines that the 3rd dutycycle is the acceptable maximum duty cycle of the first dcdc converter; And when the power needed for the successive load that input impedance variable device 22 connects is less than the peak power of photovoltaic cell, determine the dutycycle of the 3rd dutycycle for photovoltaic cell can be made to export the voltage of the power needed for successive load, and the 3rd dutycycle determined is exported to the first logic drive circuit 921;

First logic drive circuit 921, specifically for determining dutycycle minimum in the first dutycycle and the 3rd dutycycle that receive, generating the first adjustment drive singal that dutycycle is the minimum dutycycle determined and exporting to the first dcdc converter 221.

When the power needed for the successive load that input impedance variable device connects is less than the peak power of photovoltaic cell, voltage control circuit, first driving logic circuit and a DCDC control circuit can control the input impedance that the first dcdc converter changes self, the output power from photovoltaic cells is made to be less than the peak power of photovoltaic cell, the output voltage simultaneously controlling photovoltaic cell is greater than its maximum power point voltage, that is, first driving logic circuit can generate the dutycycle of the first adjustment drive singal when dutycycle is less than photovoltaic cell Maximum Power Output point voltage, and generate the first adjustment drive singal of phase, the input impedance of control inputs impedance variable device increases.Therefore, when the power needed for the successive load that input impedance variable device connects is less than the peak power of photovoltaic cell, first driving logic circuit can determine minimum dutycycle from the multiple dutycycles received, and generate the first adjustment drive singal export to the first dcdc converter that dutycycle is the minimum dutycycle determined, the input impedance of input impedance variable device is increased, thus the voltage making photovoltaic cell export to input impedance variable device increase, power reduction.

Further, as shown in figure 18, the control circuit that the embodiment of the present invention provides also comprises the second DC-to-dc DCDC control circuit 95;

2nd DCDC control circuit 95, when being not less than for the power needed for the successive load that connects at input impedance variable device the peak power that photovoltaic cell exports, determine that the 4th dutycycle is the acceptable maximum duty cycle of the first dcdc converter 221, and determine that the 5th dutycycle is the acceptable maximum duty cycle of the second dcdc converter 222; And when the power needed for the successive load that input impedance variable device connects is less than the peak power of this photovoltaic cell, determine that the 4th dutycycle and the 5th dutycycle are the dutycycle that photovoltaic cell can be made to export the voltage of the power needed for successive load, and export the 4th dutycycle to the first driving logic circuit 221, export the 5th dutycycle to the second driving logic circuit 222;

First logic drive circuit 921, specifically for determining dutycycle minimum in the first dutycycle and the 4th dutycycle that receive, generating the first adjustment drive singal that dutycycle is the minimum dutycycle determined and exporting to described first dcdc converter 221;

Second logic drive circuit 922, specifically for determining dutycycle minimum in the second dutycycle and the 5th dutycycle that receive, generating the second adjustment drive singal that dutycycle is the minimum dutycycle determined and exporting to the second dcdc converter 222.

When the power needed for the successive load that input impedance variable device connects is less than the peak power of photovoltaic cell, the input impedance of the first dcdc converter can be changed by voltage control circuit, the first driving logic circuit and the 2nd DCDC control circuit, or the input impedance of the second dcdc converter is changed by adjustable extent increasing circuit, the second driving logic circuit and the 2nd DCDC control circuit, make the output power from photovoltaic cells be less than the peak power of photovoltaic cell, the output voltage simultaneously controlling photovoltaic cell is greater than its maximum power point voltage.Therefore, when the power needed for the successive load that input impedance variable device connects is less than the peak power of photovoltaic cell, first driving logic circuit can determine minimum dutycycle from the multiple dutycycles received, and generate the first adjustment drive singal export to the first dcdc converter that dutycycle is the minimum dutycycle determined, second driving logic circuit can determine minimum dutycycle from the multiple dutycycles received, and generate the second adjustment drive singal export to the second dcdc converter that dutycycle is the minimum dutycycle determined, the input impedance of input impedance variable device is increased, thus the voltage making photovoltaic cell export to input impedance variable device increases, power reduction.If the dutycycle of the first adjustment drive singal is the dutycycle that the 2nd DCDC control circuit exports, so the first dcdc converter changes the input impedance of self, thus the input impedance of input impedance variable device is increased; If the dutycycle of the second adjustment drive singal is the dutycycle that the 2nd DCDC control circuit exports, so the second dcdc converter changes the input impedance of self, thus the input impedance of input impedance variable device is increased.

Further, as shown in Figure 19 a and Figure 19 b, the input impedance variable device that control circuit that the embodiment of the present invention provides connects also comprises DC filter 223, DC filter 223, for the successive load that input impedance variable device 22 connects is exported in the signal filtering received.In Figure 19 a, input impedance variable device 22 also comprises the first dcdc converter 221, logical block 92 is driven only to comprise the first driving logic circuit 921, input voltage control module 91 only comprises voltage control circuit 911, and the signal that DC filter 223 receives is the direct current signal that the first dcdc converter 221 exports; In Figure 19 b, input impedance variable device 22 also comprises the first dcdc converter 221 and the second dcdc converter 222, logical block 92 is driven to comprise the first driving logic circuit 921 and the second driving logic circuit 922, input voltage control module 91 comprises voltage control circuit 911 and adjustable extent increasing circuit 912, and the signal that DC filter 223 receives is the direct current signal that the second dcdc converter 222 exports.

Further, as shown in Figure 20 a and Figure 20 b, isolating transformer 224 is also comprised in the input impedance variable device that the control circuit that the embodiment of the present invention provides connects, isolating transformer 224 connects DC filter 223, and the signal received for the signal that exported by photovoltaic cell and successive load is isolated.In Figure 20 a, input impedance variable device 22 also comprises the first dcdc converter 221, logical block 92 is driven only to comprise the first driving logic circuit 921, input voltage control circuit 91 only comprises voltage control circuit 911, and the signal that isolating transformer 224 receives is the direct current signal that the first dcdc converter 221 exports; In Figure 20 b, input impedance variable device 22 also comprises the first dcdc converter 221 and the second dcdc converter 222, logical block 92 is driven to comprise the first driving logic circuit 921 and the second driving logic circuit 922, input voltage control module 91 comprises voltage control circuit 911 and adjustable extent increasing circuit 912, and the signal that isolating transformer 224 receives is the direct current signal that the second dcdc converter 222 exports.

Further, as shown in Figure 21 a and Figure 21 b, the input impedance variable device that the control circuit that the embodiment of the present invention provides connects also comprises inverter 225, also comprises inverse changing driving circuit 96 in control circuit 24;

Inverter 225, changes the direct current signal received into AC signal under the control of inversion drive singal that exports at inverse changing driving circuit 96;

When input impedance variable device 22 comprises the first dcdc converter 221, the direct current signal received from the first dcdc converter 221 is converted to AC signal by inverter 225; When input impedance variable device 22 comprises the first dcdc converter 221 and the second dcdc converter 222, the direct current signal received from the second dcdc converter 222 is converted to AC signal by inverter 225;

Inverse changing driving circuit 96, for the voltage and current determination inversion drive singal exported according to inverter 225.

Each several part in above-mentioned control circuit can pass through digital signal processor (DSP, Digital SignalProcessor) chip and realize, and also can be realized by mimic channel.Above-mentioned step-up DC/DC transducer can adopt Boost circuit, or other output voltage is not less than the converter circuit of input voltage; Above-mentioned voltage-dropping type dcdc converter can adopt Buck converter circuit, LLC circuit, normal shock, circuit of reversed excitation; Half-bridge converter circuit, full-bridge converter circuit etc.

The embodiment of the present invention also provides a kind of electricity generation system, comprises the control circuit that the embodiment of the present invention provides.

Through the above description of the embodiments, those skilled in the art can be well understood to the embodiment of the present invention can by hardware implementing, and the mode that also can add necessary general hardware platform by software realizes.Based on such understanding, the technical scheme of the embodiment of the present invention can embody with the form of software product, it (can be CD-ROM that this software product can be stored in a non-volatile memory medium, USB flash disk, portable hard drive etc.) in, comprise some instructions and perform method described in each embodiment of the present invention in order to make a computer equipment (can be personal computer, server, or the network equipment etc.).

It will be appreciated by those skilled in the art that accompanying drawing is the schematic diagram of a preferred embodiment, the module in accompanying drawing or flow process might not be that enforcement the present invention is necessary.

It will be appreciated by those skilled in the art that the module in the device in embodiment can carry out being distributed in the device of embodiment according to embodiment description, also can carry out respective change and be arranged in the one or more devices being different from the present embodiment.The module of above-described embodiment can merge into a module, also can split into multiple submodule further.

The invention described above embodiment sequence number, just to describing, does not represent the quality of embodiment.

Obviously, those skilled in the art can carry out various change and modification to the present invention and not depart from the spirit and scope of the present invention.Like this, if these amendments of the present invention and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these change and modification.

Claims

1. a control method, is characterized in that, comprising:

2. the method for claim 1, it is characterized in that, if described input impedance variable device comprises the first DC-to-dc dcdc converter, then output to the voltage of input impedance variable device and the voltage difference determination dutycycle of target voltage according to photovoltaic cell, specifically comprise:

The voltage difference of the voltage and target voltage that photovoltaic cell are outputted to input impedance variable device carries out amplifying and compensating; If amplification and the voltage difference after compensating in the first preset range, then determine the first dutycycle according to described voltage difference; If amplification and the voltage difference after compensating are not more than the minimum value of the first preset range, determine that the first dutycycle is the acceptable minimum duty cycle of the first dcdc converter; If amplification and the voltage difference after compensating are not less than the maximal value of the first preset range, determine that the first dutycycle is the acceptable maximum duty cycle of the first dcdc converter;

The described dutycycle according to determining generates adjustment drive singal, for adjusting the input impedance of input impedance variable device, specifically comprises:

The first adjustment drive singal is generated, for adjusting the input impedance of the first dcdc converter according to the first dutycycle determined.

3. method as claimed in claim 2, it is characterized in that, if described input impedance variable device also comprises the second dcdc converter be connected with the first DC-to-dc dcdc converter, then output to the voltage of input impedance variable device and the voltage difference determination dutycycle of target voltage according to photovoltaic cell, also comprise:

Determine the voltage of voltage difference and bias voltage after amplifying and compensating with; If the voltage determined and in the second preset range, according to the voltage determined with determine the second dutycycle; If the voltage determined and when being not more than the minimum value of the second preset range, then determine that the second dutycycle is the acceptable minimum duty cycle of the second dcdc converter; If the voltage determined and when being not less than the maximal value of the second preset range, then determine that the second dutycycle is the acceptable maximum duty cycle of the second dcdc converter; Described bias voltage the first dcdc converter be step-up DC/DC transducer, the second dcdc converter equals the difference of the maximal value of the second preset range and the minimum value of the first preset range when being voltage-dropping type dcdc converter, the first dcdc converter be voltage-dropping type dcdc converter, the second dcdc converter equals the difference of the minimum value of the second preset range and the maximal value of the first preset range when being step-up DC/DC transducer;

The described dutycycle according to determining generates adjustment drive singal, for adjusting the input impedance of input impedance variable device, also comprises:

The second adjustment drive singal is generated, for adjusting the input impedance of the second dcdc converter according to the second dutycycle determined.

4. method as claimed in claim 2, it is characterized in that, described method also comprises:

When the power needed for the successive load that described input impedance variable device connects is not less than the peak power of photovoltaic cell, determine that the 3rd dutycycle is the acceptable maximum duty cycle of the first dcdc converter; When the power needed for the successive load that described input impedance variable device connects is less than the peak power of photovoltaic cell, determine the dutycycle of the 3rd dutycycle for photovoltaic cell can be made to export the voltage of the power needed for described successive load;

Generate the first adjustment drive singal according to the first dutycycle determined, specifically comprise:

Generating dutycycle is that first of dutycycle minimum in the first dutycycle and the 3rd dutycycle adjusts drive singal.

5. method as claimed in claim 3, it is characterized in that, described method also comprises:

When the power needed for the successive load that described input impedance variable device connects is not less than the peak power of photovoltaic cell, determine that the 4th dutycycle is the acceptable maximum duty cycle of the first dcdc converter, determine that the 5th dutycycle is the acceptable maximum duty cycle of the second dcdc converter; When the power needed for the successive load that described input impedance variable device connects is less than the peak power of photovoltaic cell, determine that the 4th dutycycle and the 5th dutycycle are the dutycycle that photovoltaic cell can be made to export the voltage of the power needed for described successive load;

Generating dutycycle is that first of dutycycle minimum in the first dutycycle and the 4th dutycycle adjusts drive singal;

Generate the second adjustment drive singal according to the second dutycycle determined, specifically comprise:

Generating dutycycle is that second of dutycycle minimum in the second dutycycle and the 5th dutycycle adjusts drive singal.

6. the method as described in as arbitrary in claims 1 to 3, it is characterized in that, described input impedance variable device comprises inverter;

According to the voltage and current determination inversion drive singal that described inverter exports, change the direct current signal received into AC signal for controlling described inverter.

7. a control device, is characterized in that, comprising:

8. device as claimed in claim 7, is characterized in that, described determination module specifically for:

When described input impedance variable device comprises the first DC-to-dc dcdc converter, the voltage difference of the voltage and target voltage that photovoltaic cell are outputted to input impedance variable device carries out amplifying and compensating; If amplification and the voltage difference after compensating in the first preset range, then determine the first dutycycle according to described voltage difference; If amplification and the voltage difference after compensating are not more than the minimum value of the first preset range, determine that the first dutycycle is the acceptable minimum duty cycle of the first dcdc converter; If amplification and the voltage difference after compensating are not less than the maximal value of the first preset range, determine that the first dutycycle is the acceptable maximum duty cycle of the first dcdc converter;

Described generation module specifically for:

9. device as claimed in claim 8, is characterized in that, described determination module also for:

When described input impedance variable device also comprises the second dcdc converter be connected with the first DC-to-dc dcdc converter, determine the voltage of voltage difference and bias voltage after amplifying and compensating with; If the voltage determined and in the second preset range, according to the voltage determined with determine the second dutycycle; If the voltage determined and when being not more than the minimum value of the second preset range, then determine that the second dutycycle is the acceptable minimum duty cycle of the second dcdc converter; If the voltage determined and when being not less than the maximal value of the second preset range, then determine that the second dutycycle is the acceptable maximum duty cycle of the second dcdc converter; Described bias voltage the first dcdc converter be step-up DC/DC transducer, the second dcdc converter equals the difference of the maximal value of the second preset range and the minimum value of the first preset range when being voltage-dropping type dcdc converter, the first dcdc converter be voltage-dropping type dcdc converter, the second dcdc converter equals the difference of the minimum value of the second preset range and the maximal value of the first preset range when being step-up DC/DC transducer;

Described generation module also for:

10. device as claimed in claim 8, is characterized in that, described determination module also for:

Described generation module specifically for:

Generating dutycycle is that first of dutycycle minimum in the first dutycycle and the 3rd dutycycle adjusts drive singal, for adjusting the input impedance of the first dcdc converter.

11. devices as claimed in claim 9, is characterized in that, described determination module also for:

Described generation module specifically for:

Generating dutycycle is that first of dutycycle minimum in the first dutycycle and the 4th dutycycle adjusts drive singal, for adjusting the input impedance of the second dcdc converter; And to generate dutycycle be that second of dutycycle minimum in the second dutycycle and the 5th dutycycle adjusts drive singal, for adjusting the input impedance of the second dcdc converter.

12. 1 kinds of control circuits, is characterized in that, comprise MPPT maximum power point tracking MPPT unit, input voltage control module, drive logical block; Described driving logical block connects described input voltage control module and input impedance variable device respectively, and described MPPT unit connects described input impedance variable device and described input voltage control module respectively;

13. control circuits as claimed in claim 12, it is characterized in that, the variable device of described input impedance comprises the first DC-to-dc dcdc converter, and described input voltage control module comprises voltage control circuit, and described driving logical block comprises the first driving logic circuit;

Described voltage control circuit, for determining that photovoltaic cell outputs to the voltage of the first dcdc converter and the voltage difference of target voltage, and amplifies the voltage difference determined and compensates; And amplify and compensate after voltage difference in the first preset range time, the first dutycycle is determined according to amplification and the voltage difference after compensating, when voltage difference after amplifying and compensating is not more than the minimum value of the first preset range, determine that the first dutycycle is the acceptable minimum duty cycle of the first dcdc converter, when voltage difference after amplifying and compensating is not less than the maximal value of the first preset range, determine that the first dutycycle is the acceptable maximum duty cycle of the first dcdc converter, and the first dutycycle determined is exported to described first driving logic circuit;

Described first driving logic circuit, for generating the first adjustment drive singal and exporting to described first dcdc converter, for adjusting the input impedance of the first dcdc converter according to the first dutycycle received.

14. control circuits as claimed in claim 13, it is characterized in that, described voltage control circuit comprises subtracter, corrective network and the first pulse width generators;

Described subtracter, for determining that photovoltaic cell outputs to the described voltage of the first dcdc converter and the voltage difference of target voltage, and exports to corrective network;

Described corrective network, for amplifying the voltage difference from subtracter received and compensating, and exports to the first pulse width generators;

Described first pulse width generators, for when the voltage difference received is in the first preset range, the first dutycycle is determined according to described voltage difference, when the voltage difference received is not more than the minimum value of the first preset range, determine that the first dutycycle is the acceptable minimum duty cycle of the first dcdc converter, when the voltage difference received is not less than the maximal value of the first preset range, determine that the first dutycycle is the acceptable maximum duty cycle of the first dcdc converter, and the first dutycycle determined is exported to described first driving logic circuit.

15. control circuits as claimed in claim 13, it is characterized in that, the variable device of input impedance also comprises the second dcdc converter, described second dcdc converter connects described first dcdc converter, described input voltage control module also comprises adjustable extent increasing circuit, and described driving logical block also comprises the second driving logic circuit;

Described adjustable extent increasing circuit, for determine the voltage of the amplification that the voltage control circuit that receives exports and the voltage difference after compensating and bias voltage with; And time at the voltage determined and in the second preset range, according to the voltage determined and determine the second dutycycle, at the voltage determined with when being not more than the minimum value of the second preset range, determine that the second dutycycle is the acceptable minimum duty cycle of the second dcdc converter, at the voltage determined with when being not less than the maximal value of the second preset range, determine that the second dutycycle is the acceptable maximum duty cycle of the second dcdc converter; And the second dutycycle determined is exported to described second driving logic circuit; Described bias voltage the first dcdc converter be step-up DC/DC transducer, the second dcdc converter equals the difference of the maximal value of the second preset range and the minimum value of the first preset range when being voltage-dropping type dcdc converter, the first dcdc converter be voltage-dropping type dcdc converter, the second dcdc converter equals the difference of the minimum value of the second preset range and the maximal value of the first preset range when being step-up DC/DC transducer;

Described second driving logic circuit, for generating the second adjustment drive singal and exporting to described second dcdc converter, for adjusting the input impedance of the second dcdc converter according to the second dutycycle received.

16. control circuits as claimed in claim 15, it is characterized in that, described adjustable extent increasing circuit comprises totalizer and the second pulse width generators;

Described totalizer, for determine the voltage of the amplification that the voltage control circuit that receives exports and the voltage difference after compensating and the first bias voltage with, and be transferred to the second pulse width generators;

Described second pulse width generators, for at the voltage from described totalizer received and in the second preset range time, according to described voltage and determine the second dutycycle, at described voltage with when being not more than the minimum value of the second preset range, determine that the second dutycycle is the acceptable minimum duty cycle of the second dcdc converter, at described voltage with when being not less than the minimum value of the second preset range, determine that the second dutycycle is the acceptable maximum duty cycle of the second dcdc converter; And the second dutycycle determined is exported to described second driving logic circuit.

17. control circuits as claimed in claim 13, it is characterized in that, described control circuit also comprises the first DC-to-dc DCDC control circuit;

A described DCDC control circuit, when being not less than the peak power of photovoltaic cell for the power needed for the successive load in described input impedance variable device connection, determines that the 3rd dutycycle is the acceptable maximum duty cycle of the first dcdc converter; And when the power needed for the successive load that described input impedance variable device connects is less than the peak power of photovoltaic cell, determine the dutycycle of the 3rd dutycycle for photovoltaic cell can be made to export the voltage of the power needed for described successive load, and the 3rd dutycycle determined is exported to the first logic drive circuit;

Described first logic drive circuit, specifically for determining dutycycle minimum in the first dutycycle and the 3rd dutycycle that receive, generating the first adjustment drive singal that dutycycle is the minimum dutycycle determined and exporting to described first dcdc converter.

18. control circuits as claimed in claim 15, it is characterized in that, described control circuit also comprises the second DC-to-dc DCDC control circuit;

Described 2nd DCDC control circuit, when being not less than the peak power of photovoltaic cell for the power needed for the successive load in described input impedance variable device connection, determine that the 4th dutycycle is the acceptable maximum duty cycle of the first dcdc converter, determine that the 5th dutycycle is the acceptable maximum duty cycle of the second dcdc converter; And when the power needed for the successive load that described input impedance variable device connects is less than the peak power of photovoltaic cell, determine that the 4th dutycycle and the 5th dutycycle are the dutycycle that photovoltaic cell can be made to export the voltage of the power needed for described successive load; And export the 4th dutycycle to the first driving logic circuit, and export the 5th dutycycle to the second driving logic circuit;

Described first logic drive circuit, specifically for determining dutycycle minimum in the first dutycycle and the 4th dutycycle that receive, generating the first adjustment drive singal that dutycycle is the minimum dutycycle determined and exporting to described first dcdc converter;

Described second logic drive circuit, specifically for determining dutycycle minimum in the second dutycycle and the 5th dutycycle that receive, generating the second adjustment drive singal that dutycycle is the minimum dutycycle determined and exporting to described second dcdc converter.

19. as arbitrary in claim 12 ~ 18 as described in control circuit, it is characterized in that, also DC filter is comprised in the input impedance variable device that described control circuit connects, described DC filter, for by the signal filtering received and export to described input impedance variable device connect successive load.

20. control circuits as claimed in claim 19, it is characterized in that, also isolating transformer is comprised in the input impedance variable device that described control circuit connects, described isolating transformer connects described DC filter, and the signal that described isolating transformer is used for the signal of photovoltaic cell output and successive load receive is isolated.

21. as arbitrary in claim 12 ~ 16 as described in control circuit, it is characterized in that, also comprise inverter in the input impedance variable device that described control circuit connects, in described control circuit, also comprise inverse changing driving circuit;

Described inverter, changes the direct current signal received into AC signal under the control of inversion drive singal that exports at described inverse changing driving circuit;

Described inverse changing driving circuit, for the voltage and current determination inversion drive singal exported according to described inversion device.

22. 1 kinds of electricity generation systems, is characterized in that, comprise the arbitrary described control circuit of claim 12 ~ 21.