CN1627225A - Method for tracing maximum power for solar power system and equipment - Google Patents

Method for tracing maximum power for solar power system and equipment Download PDF

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Publication number
CN1627225A
CN1627225A CNA2003101205481A CN200310120548A CN1627225A CN 1627225 A CN1627225 A CN 1627225A CN A2003101205481 A CNA2003101205481 A CN A2003101205481A CN 200310120548 A CN200310120548 A CN 200310120548A CN 1627225 A CN1627225 A CN 1627225A
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converter
output current
solar cell
maximum power
solar
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蔡文荫
周宏亮
吴晋昌
吴坤德
苏钧立
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Taida Electronic Industry Co Ltd
Delta Optoelectronics Inc
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Delta Optoelectronics Inc
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Abstract

This invention provides a method for tracing the maximum power and a device for a solar energy generation system. The system includes at least a solar energy battery and a DC/AC converter, the method is that an output current of said DC/AC converter or a DC output voltage of said solar energy battery are adjusted to observe the DC output voltage or the output current variation generated by said DC output voltage of current then again to adjust said output current or DC voltage in the same direction with the variations and to repeat the above steps to reach the aim of tracing the maximum power point of said system.

Description

The maximum power tracing method of solar power system and device
Technical field
The present invention relates to a kind of maximum power tracing method and device of solar power system, refer to a kind of maximum power tracing method and device that uses the solar power system of current mode solar cell especially.
Background technology
Because the high development of industry not only makes tellurian fossil energy exhausted fast, more cause the severe contamination and the transition of global environment in recent years.Based on the viewpoint of variety of energy sources with the source diversification and the permanent energy, sun power is except fossil fuel, waterpower and nuclear energy power generation, the new forms of energy that tool potential value must be developed, as effectively utilizing sun power, not only can solve the problem of energy demand, and clean free of contamination sun power, the abominable situation that more can reduce environmental pollution and reduce Global Greenhouse Effect.According to estimates next two decades whole world sun power use will grow up so its dark tool development potentiality every year with 15% to 35% ratio fast.
The main gordian technique that the sunshine electric energy utilizes is solar battery technology and power conversions interfacing; And the gordian technique of power conversions interfacing is maximum power tracing technology and anti-island effect technology, and wherein the maximum power tracing technology is that present industry drops into the focus technology that more mental and physical efforts are demanded urgently improving.
In the middle of at present numerous maximum power tracing technology, on behalf of the patent case, the most normal adopted then belong to " disturbance observation " then see also Japan and speciallyyed permit out hope and disclose designation " spy opens flat 8-44445 number " and reach " spy opens flat 8-44446 number ".
In " spy opens flat 8-44445 number ", be meant a kind of output power of periodically measuring solar cell and adjusting the VD of solar cell, with the maximum power tracing method and the device of the output power that increases solar cell.When its technical characterictic is by the VD of adjustment solar cell, observe the change direction of solar cell output power; If after the VD of adjusting solar cell, the output power of solar cell increases, and then adjusts the VD of solar cell toward equidirectional continuation; Otherwise, if the output power of solar cell reduces, then toward the VD of adjusting solar cell in the other direction; In addition, reach a default value if the VD of solar cell needs to adjust number of times toward same direction, then the voltage difference of Tiao Zhenging can be more and more big; On the contrary, if the back and forth adjustment number of times of the VD of solar cell on the direction that increases and reduce reaches a default value, then the voltage difference of adjusting needs more and more little.
And in " spy opens flat 8-44446 number ", maximum power tracing method of being narrated and device are not then mentioned in order to replenish " spy opens flat 8-44445 number " lining; That is to say that if after the VD of adjusting solar cell, the output power of solar cell does not have any variation, then the VD of solar cell also remains unchanged.
Two above-mentioned Jap.P.s have intactly been stated the technical characterictic of the most normal " the disturbance observation " that is used at present, yet, this maximum power tracing method is still because of calculating the output power of solar power system, cause the circuit arrangement complexity, cost can't reduce, and makes the researcher urgently think the method for improvement always.
In order to solve the bottleneck that occurs in the above-mentioned prior art, the invention provides a kind of maximum power tracing method and device of solar power system.It below is brief description of the present invention.
Summary of the invention
Fundamental purpose of the present invention is for proposing a kind of maximum power tracing method and device of solar power system, it is by the output current amplitude that changes AC/DC converter and observes the variation situation of solar cell VD, adjustment direction with decision current amplitude next time, and can be applied to simultaneously in the occasion of single switch and two converters, reaching the purpose of the Maximum Power Output that sun-tracing can battery, and needn't go to calculate the output power of solar power system veritably.
According to main conception of the present invention, a kind of maximum power tracing method of solar power system is proposed, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this maximum power tracing method comprises the following steps: to adjust an output current of this AC/DC converter; Observe the direct current output voltage variable quantity that a direct current output voltage of this solar cell is produced; Equidirectionally adjust this output current once more with this VD variable quantity; And repeat above-mentioned steps in regular turn.
According to another conception of the present invention, a kind of maximum power tracing method of solar power system is proposed, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this maximum power tracing method comprises the following steps: that (a) provides an output current initial value of this AC/DC converter; (b) measure the direct current output voltage initial value that this solar cell is produced according to this output current initial value; (c) provide an output current reference value of this AC/DC converter, and make this solar power system under this output current reference value, operate a time interval; (d) measure the direct current output voltage reference value that this solar cell is produced according to this output current reference value; (e) relatively this VD reference value changes with respect to one of this VD initial value; (f) change this output current reference value with this variation equidirectionally, and replace this VD initial value with this VD reference value after changing; And (g) repeating step (c)~(f).
According to a conception more of the present invention, a kind of maximum power tracing device of solar power system is proposed, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this solar cell and this AC/DC converter produce a direct current output voltage and an output current respectively, this maximum power tracing device comprises: a digital processing unit, be electrically connected on this solar cell and this AC/DC converter, this digital processing unit is this VD and this output current that feeds back in order to receive, and produces a control signal according to the direct current output voltage variable quantity that this VD produced; An and pulse-width-modulation driver, be electrically connected on this AC/DC converter and this digital processing unit, this pulse-width-modulation driver is to produce a pulse-width signal according to this control signal, makes this AC/DC converter to adjust this output current with this VD variable quantity equidirectionally.
Have more a storage capacitor according to the described maximum power tracing device of above-mentioned conception, be connected in parallel in this solar cell and this AC/DC converter.
According to above-mentioned conception, wherein this AC/DC converter is a DC/AC inverter.
According to above-mentioned conception, wherein this digital processing unit comprises: a voltage detection unit, in order to receive the voltage of the distribution system of feeding back that this solar power system connected, to produce a voltage detection signal; One phase-locked loop control module is in order to receive this voltage detection signal, to produce a phase-locked loop signal; One multiplier multiplies each other in order to the amplitude with this output current of this phase-locked loop signal and feedback, to produce an output current reference signal; And a comparer, subtract each other in order to this output current, to produce this control signal this output current reference signal and feedback.
According to a conception more of the present invention, a kind of maximum power tracing device of solar power system is proposed, wherein this solar power system comprises a solar cell at least, one DC-DC converter and an AC/DC converter, and this solar cell, this DC-DC converter and this AC/DC converter produce one first VD respectively, one second VD and an output current, this maximum power tracing device comprises: a digital processing unit, be electrically connected on this solar cell, this DC-DC converter and this AC/DC converter, this digital processing unit is this second VD and this output current that feeds back in order to receive, and produces a control signal according to the direct current output voltage variable quantity that this second VD is produced; An and pulse-width-modulation driver, be electrically connected on this DC-DC converter, this AC/DC converter and this digital processing unit, this pulse-width-modulation driver is to produce a pulse-width signal according to this control signal, makes this DC-DC converter produce this second VD and this AC/DC converter to adjust this output current with this VD variable quantity equidirectionally.
According to above-mentioned conception, wherein this DC-DC converter is a boost converter, in order to receiving this first VD, and is boosted to produce this second VD.
According to above-mentioned conception, wherein this second VD has a fixed ratio with respect to this first VD.
According to above-mentioned conception, wherein this second VD is a fixed value.
According to above-mentioned conception, wherein this AC/DC converter is a DC/AC inverter.
According to above-mentioned conception, also have one first storage capacitor and one second storage capacitor, wherein this first storage capacitor is connected in parallel in this solar cell and this DC-DC converter, and this second storage capacitor is connected in parallel in this DC-DC converter and this AC/DC converter.
According to above-mentioned conception, wherein this digital processing unit comprises: a voltage detection unit, in order to receive the voltage of the distribution system of feeding back that this solar power system connected, to produce a voltage detection signal; One phase-locked loop control module is in order to receive this voltage detection signal, to produce a phase-locked loop signal; One multiplier multiplies each other in order to the amplitude with this output current of this phase-locked loop signal and feedback, to produce an output current reference signal; And one first comparer, subtract each other in order to this output current, to produce this control signal this output current reference signal and feedback.
According to main conception of the present invention, a kind of maximum power tracing method of solar power system is proposed, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this maximum power tracing method comprises the following steps: to adjust a direct current output voltage of this solar cell; Observe the output current amplitude variations amount that an output current of this AC/DC converter is produced; Equidirectionally adjust this VD once more with this output current variable quantity; And repeat above-mentioned steps in regular turn.
According to another conception of the present invention, a kind of maximum power tracing method of solar power system is proposed, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this maximum power tracing method comprises the following steps: that (a) provides a direct current output voltage initial value of this solar cell; (b) measure the output current amplitude initial value that this AC/DC converter is produced according to this VD initial value; (c) provide a direct current output voltage reference value of this solar cell, and make this solar power system under this VD reference value, operate a time interval; (d) measure the output current amplitude reference value that this AC/DC converter is produced according to this VD reference value; (e) relatively this output current reference value changes with respect to one of this output current amplitude initial value; (f) change this VD reference value with this variation equidirectionally, and replace this output current amplitude initial value with this output current amplitude reference value after changing; And (g) repeating step (c)~(f).
According to a conception more of the present invention, a kind of maximum power tracing device of solar power system is proposed, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this solar cell and this AC/DC converter produce a direct current output voltage and an output current respectively, this maximum power tracing device comprises: a digital processing unit, be electrically connected on this solar cell and this AC/DC converter, this VD and this output current that this digital processing unit feeds back in order to reception, and according to the living control signal of the output current amplitude variations volume production that this output current produced; An and pulse-width-modulation driver, be electrically connected on this AC/DC converter and this digital processing unit, this pulse-width-modulation driver is to produce a pulse-width signal according to this control signal, makes this solar cell to adjust this VD with this output current amplitude variations amount equidirectionally.
According to the described maximum power tracing device of above-mentioned conception, have more a storage capacitor, be connected in parallel in this solar cell and this AC/DC converter.
According to above-mentioned conception, wherein this AC/DC converter is a DC/AC inverter.
According to above-mentioned conception, wherein this digital processing unit comprises: a voltage detection unit, in order to receive the voltage of the distribution system of feeding back that this solar power system connected, to produce a voltage detection signal; One phase-locked loop control module is in order to receive this voltage detection signal, to produce a phase-locked loop signal; One first comparer subtracts each other in order to this VD and a setting voltage that will feed back, to produce a direct current output voltage error signal; One pi controller is in order to receive this VD error signal, to produce an output current amplitude signal; One multiplier is in order to multiply each other this phase-locked loop signal and this output current amplitude signal, to produce an output current reference signal; And a comparer, subtract each other in order to this output current, to produce this control signal this output current reference signal and feedback.
According to a conception more of the present invention, a kind of maximum power tracing device of solar power system is proposed, wherein this solar power system comprises a solar cell at least, one DC-DC converter and an AC/DC converter, and this solar cell, this DC-DC converter and this AC/DC converter produce one first VD respectively, one second VD and an output current, this maximum power tracing device comprises: a digital processing unit, be electrically connected on this solar cell, this DC-DC converter and this AC/DC converter, this second VD and this output current that this digital processing unit feeds back in order to reception, and according to the living control signal of the output current amplitude variations volume production that this output current produced; An and pulse-width-modulation driver, be electrically connected on this DC-DC converter, this AC/DC converter and this digital processing unit, this pulse-width-modulation driver produces a pulse-width signal according to this control signal, makes this DC-DC converter produce this second VD and this solar cell to adjust this first VD with this output current amplitude variations amount equidirectionally.
According to above-mentioned conception, wherein this DC-DC converter is a boost converter, in order to receiving this first VD, and is boosted to produce this second VD.
According to above-mentioned conception, wherein this second VD has a fixed ratio with respect to this first VD.
According to above-mentioned conception, wherein this second VD is a fixed value.
According to above-mentioned conception, wherein this AC/DC converter is a DC/AC inverter.
According to above-mentioned conception, have more one first storage capacitor and one second storage capacitor, wherein this first storage capacitor is connected in parallel in the junction of this solar cell and this DC-DC converter, and this second storage capacitor is connected in parallel in this DC-DC converter and this AC/DC converter.
According to above-mentioned conception, wherein this digital processing unit comprises: a voltage detection unit, in order to receive the voltage of the distribution system of feeding back that this solar power system connected, to produce a voltage detection signal; One phase-locked loop control module is in order to receive this voltage detection signal, to produce a phase-locked loop signal; One first comparer subtracts each other in order to this VD and a setting voltage that will feed back, to produce a direct current output voltage error signal; One pi controller is in order to receive this VD error signal, to produce an output current amplitude signal; One multiplier is in order to multiply each other this phase-locked loop signal and this output current amplitude signal, to produce an output current reference signal; And a comparer, subtract each other in order to this output current, to produce this control signal this output current reference signal and feedback.
Description of drawings
Fig. 1 is the solar power system block scheme of a preferred embodiment of the present invention;
Fig. 2 A is the process flow diagram (the inverter output current is adjusted in the variation according to the solar cell VD) of maximum power tracing method of the present invention;
Fig. 2 B is the process flow diagram (the solar cell VD is adjusted in the variation according to the inverter output current) of maximum power tracing method of the present invention;
Fig. 3 is used in the solar power system synoptic diagram of single switch framework for maximum power tracing method of the present invention;
Fig. 4 A is the digital processing unit running block scheme (the inverter output current is adjusted in the variation according to the solar cell VD) of Fig. 3;
Fig. 4 B is the digital processing unit running block scheme (the solar cell VD is adjusted in the variation according to the inverter output current) of Fig. 3;
Fig. 5 is used in the solar power system synoptic diagram of two converter architecture for maximum power tracing method of the present invention;
Fig. 6 is the DC-DC converter circuit diagram of Fig. 5; And
Fig. 7 is the fixing controlling party block diagram of VD.
Wherein, description of reference numerals is as follows:
1 solar power system
10 solar cells, 11 AC/DC converters
12 maximum power tracing devices, 13 distribution systems
3 solar power systems
30 solar cells, 31 DC/AC inverters
32 digital processing units, 33 pulse-width-modulation driver
34 storage capacitors, 35 distribution systems
40 voltage detection units, 41 phase-locked loop unit
42 multipliers, 43 comparers
44 drivers, 45 comparers
46 pi controllers
5 solar power systems
50 solar cells, 51 DC-DC converters
52 DC/AC inverters, 53 digital processing units
54 pulse-width-modulation driver
55 storage capacitors, 56 storage capacitors
57 distribution systems
6 boost converters
60 inductance, 61 electronic power switches
62 diodes
70 comparers, 71 pi controllers
72 pulse-width-modulation driver
Embodiment
In order to make the present invention obtain more in depth understanding, be described in further detail below in conjunction with accompanying drawing.
See also Fig. 1, it is the solar power system block scheme of a preferred embodiment of the present invention, wherein, solar power system 1 is made of solar cell 10, AC/DC converter 11 and maximum power tracing device 12, becomes the AC energy of loopback distribution system 13 in order to the transform light energy with the sun.And the technical characterstic of maximum power tracing device 12 proposed by the invention promptly is with the different of How It Works maximum of conventional apparatus, do not need the output power of actual computation solar power system 1, and only need adjust the amplitude of the output current of AC/DC converter 11, can reach the purpose of maximum power tracing, its ultimate principle is described as follows:
Voltage in this hypothesis distribution system 13 is
vs(t)=V psin(ωt) (1)
Because the output current of AC/DC converter 11 also be a sine wave and with the voltage same-phase of distribution system 13, so the output current of AC/DC converter 11 can be expressed as
i inv(t)=I invsin(ωt) (2)
Therefore the output real power of AC/DC converter 11 can be expressed as
P inv(t)=(1/2)(V pI inv) (3)
In addition, the output power of solar cell 10 can be expressed as
P solar=V solar(t)I solar(t) (4)
Suppose AC/DC converter 11 and no power waste, meaning i.e. (3) formula equals (4) formula, so
P solar=P inv(t)=V solar(t)I solar(t)=(1/2)(V pI inv) (5)
At first, because the output current I of solar cell 10 Solar(t) be with day illuminance and temperature change, therefore uncontrollable; Moreover, the voltage amplitude V of distribution system 13 pBecause of changing little and itself is also uncontrollable, therefore under special time, it can be considered as a constant.Hence one can see that, the output power P of solar power system 1 SolarWe can say the output current amplitude I that is proportional to AC/DC converter 11 fully InvAnd the know-why of maximum power tracing method of the present invention is by changing the output current amplitude I of AC/DC converter 11 Inv, and observe the VD V of solar cell 10 Solar(t) variation situation is with the output current amplitude I of decision AC/DC converter 11 next time InvThe adjustment direction, and needn't go to calculate the output power of solar power system 1 veritably.For instance, if the output current amplitude I of AC/DC converter 11 InvTransfer when big the VD V of solar cell 10 Solar(t) rise, then represent the output current amplitude I of AC/DC converter 11 InvCan continue to transfer big; On the contrary, if the output current amplitude I of AC/DC converter 11 InvAfter transferring greatly, the VD V of solar cell 10 Solar(t) but descend, then need oppositely downgrade the output current amplitude I of AC/DC converter 11 Inv, can vibrate back and forth at the maximum power point place at last.
See also Fig. 2 A, it is the process flow diagram of maximum power tracing method of the present invention, the inventive concept of Fig. 1 of the present invention can be illustrated in comparatively actual mode by this figure.In Fig. 2 A, at first set the amplitude (it is represented with K) of the output current initial value of AC/DC converter, and the VD initial value (it is represented with Vsolar-old) of feedback solar cell under this K value, the output current amplitude that then increases AC/DC converter again is to provide a new output current amplitude reference value (being that the K value increases), make solar power system under this new K value, postpone running a period of time at interval, and behind system stability, read the VD (it is represented with Vsolar-new) of solar cell once more, this moment is just by the comparative result of Vsolar-old and the VD Vsolar-new change direction with decision K value; If Vsolar-new>Vsolar-old then increases the K value, otherwise if Vsolar-new<Vsolar-old then reduces the K value.And after having determined new K value, just replace Vsolar-old with VD Vsolar-new, carry out next time sampling and comparison more in the same way.
In addition, the performance of maximum power tracing method of the present invention in Fig. 2 A, also being not limited to need be at the output current initial value (K value) of setting AC/DC converter, and feedback is after the VD of solar cell under this K value, output current amplitude that must " increase " AC/DC converter (being the increase of K value); Meaning promptly, the output current amplitude that can also " reduce " AC/DC converter to be providing this output current amplitude reference value (be K value increase square frame can K value reduce square frame and replace), emphasis be follow-up still be equally with VD Vsolar-new relatively with respect to after the Vsolar-old variation, more equidirectional the output current reference value K that changes.
Simultaneously, adjust the output current amplitude of AC/DC converter according to the variation of solar cell VD with respect to Fig. 2 A, maximum power tracing method of the present invention can also operate according to the mode that the output current oscillation amplitude change of AC/DC converter is adjusted the solar cell VD, shown in the process flow diagram of Fig. 2 B.Because the peak power that the maximum power tracing technology of traditional sun power is onlyed demand solar cell mostly, but do not consider the power attenuation of energy converter, yet utilize maximum power tracing technology of the present invention, but can follow the trail of whole solar power supply system, just comprise the peak power of energy converter and solar cell simultaneously, the power attenuation that also is about to energy converter is taken into account.Shown in Fig. 2 B, in order to determine the operating voltage of solar cell, need earlier at the initial value of default solar cell terminal voltage at the beginning, and feedback under this initial value digital processing unit in an output current amplitude initial value (it is represented with PI-old) of the pi controller that had, the VD that then increases solar cell is again set, make solar power system under this VD is set, postpone running a period of time at interval, and behind system stability, read an output current amplitude signal (it is represented with PI-new) of this pi controller, the change direction that just set with decision solar cell terminal voltage by the comparative result of PI-old and PI-new this moment once more; Set if PI-new 〉=PI-old then increases the VD of solar cell, otherwise set if PI-new<PI-old then reduces the VD of solar cell.And after the VD that has determined new solar cell is set, just replace PI-old with PI-new, carry out next time sampling and comparison more in the same way.
What deserves to be mentioned is, when maximum power tracing method of the present invention finds expression in the side circuit operation, all can apply to now be respectively described below under the framework of single switch and two converters:
(1) single switch framework
See also Fig. 3, it is used in the solar power system synoptic diagram of single switch framework for maximum power tracing method of the present invention, and solar power system 3 is made of solar cell 30, DC/AC inverter 31, digital processing unit 32, pulse-width-modulation driver 33 and storage capacitor 34 among the figure.Wherein, the DC power output of solar cell 30 is to convert AC energy to via storage capacitor 34 and DC/AC inverter 31, to send distribution system end 35 back to.
As shown in Figure 3, in order to carry out maximum power tracing method of the present invention, need the VD V of feedback solar cell 30 Solar(t), distribution system voltage V s(t) and the output current I of DC/AC inverter 31 Inv(t) to digital processing unit 32, digital processing unit 32 then can drive pulse-width-modulation driver 33 makes it send pulse-width signal, uses control DC/AC inverter 31 and makes it produce different inverter output current amplitude I Inv, and digital processing unit 32 is again according to because different inverter output current amplitude I InvThe VD V of the solar cell 30 that the front and back that produced are different Solar(t) do one relatively, with decision inverter output current amplitude I InvThe adjustment direction, reach the purpose of the peak power that sun-tracing can battery 30.
In addition, the embodiment of the digital processing unit among Fig. 3 32 also can be that example explains (the inverter output current is adjusted in the variation according to the solar cell VD) with the framework of Fig. 4 A.In Fig. 4 A, the feedback voltage of distribution system end is earlier after voltage detection unit 40 detects, produce a voltage detection signal, multiple produce with distribution system voltage same-phase and be a phase-locked loop signal of string ripple through phase-locked loop control module 41, again the amplitude K of the inverter output current of this phase-locked loop signal and setting is utilized after multiplier 42 multiplied each other, obtain an inverter output current reference signal, utilize comparer 43 to produce a control signal after subtracting each other the inverter output current of this inverter output current reference signal and feedback, this control signal is delivered to driver 44, to produce required width modulation (PWM) signal of switch of DC/AC inverter.
In addition, the maximum power tracing method that the mode of setting corresponding to the variation adjustment solar cell VD according to the inverter output current of Fig. 2 B operates, the embodiment of its digital processing unit 32 then must explain with the framework of Fig. 4 B.In Fig. 4 B, the feedback voltage of distribution system end earlier after voltage detection unit 40 detects, produces a voltage detection signal, produces with distribution system voltage same-phase and is a phase-locked loop signal of string ripple through phase-locked loop control module 41 again.In addition, can get a direct current output voltage error signal after utilizing comparer 45 to subtract each other the VD of solar cell and the one setting voltage, again this VD error signal proportion of utilization integral controller 46 is handled an output current amplitude signal.At last with aforesaid phase-locked loop signal therewith the output current amplitude signal utilize after multiplier 42 multiplied each other, obtain an inverter output current reference signal, utilize comparer 43 to produce a control signal after subtracting each other the inverter output current of this inverter output current reference signal and feedback, this control signal is delivered to driver 44, to produce required width modulation (PWM) signal of switch of DC/AC inverter.
Current control mode through closed loop control can make the inverter output current be tending towards this inverter output current reference signal in theory in Fig. 4 B, and pi controller 46 is output as the amplitude of this inverter output current reference signal, therefore the amplitude of this inverter output current also is tending towards the output of pi controller 46, therefore, with the output of pi controller 46 amplitude, can avoid the complicated calculations of inverter output current amplitude in the maximum power tracing process flow diagram of Fig. 2 B as the inverter output current.
(2) two converter architecture
See also Fig. 5, the solar power system synoptic diagram of its two converter architecture for maximum power tracing method of the present invention is used in, solar power system 5 is to be made of solar cell 50, DC-DC converter 51, DC/AC inverter 52, digital processing unit 53, pulse-width-modulation driver 54 and two storage capacitors 55 and 56 among the figure.Different with the single switch framework is, the DC power output of solar cell 50 is earlier to rise to the current potential that can be complementary with distribution system 57 voltages via DC-DC converter 51, sends distribution system end 57 again after DC/AC inverter 52 converts AC energy to back to; By boosting of prime DC-DC converter 51, can be so that back level DC/AC inverter 52 be more stable in operation.
Because in the solar power system 5 of two converter architecture, equally also be to utilize the amplitude of the output current that changes DC/AC inverter 52 to observe the variation of the VD of solar cell 50, with the adjustment direction of decision DC/AC inverter 52 output current amplitudes, operation principles is identical with the solar power system of single switch framework; Therefore, the control mode and the single switch framework of the DC/AC inverter in the solar power system 5 of two converter architecture are identical, and the framework of its control flow and digital processing unit 53 is also respectively as Fig. 2 and shown in Figure 4.
What deserves to be mentioned is that DC-DC converter of the present invention can be a traditional boost converter, as shown in Figure 6, wherein boost converter 6 is made up of inductance 60, electronic power switch 61 and diode 62.
On the one hand, the digital processing unit 53 among Fig. 5 then has dual mode for the control mode of DC-DC converter 51 in addition; Fixing responsibility fixing VD when below is illustrated respectively:
(a) fixing responsibility ratio
The so-called fixedly control mode of responsibility ratio be by digital processing unit 53 directly send one fixedly the pulse wave string of responsibility ratio to control the electronic power switch 61 of DC-DC converter 51, though the VD of DC-DC converter 51 is to become along with the VD of solar cell 50, but, therefore still VD can be risen to the current potential that can be complementary with distribution system voltage because DC-DC converter 51 (boost converter of Fig. 6 just) itself has fixing step-up ratio.
(b) fixing VD
The so-called fixedly control mode of VD then is to utilize closed loop control to control the VD of DC-DC converter 51 (or boost converter of the Fig. 6 that says so) by digital processing unit 53, is a fixed value and can change along with the variation of the VD of solar cell 50.See also Fig. 7, it is the fixing controlling party block diagram of VD, it is earlier to utilize comparer 70 to make comparisons the VD Vdc2 and a predeterminated voltage Vdcset of the DC-DC converter of feedback, again with comparative result warp let-off pi controller 71 and pulse-width-modulation driver 72 in regular turn, to produce the pulse wave signal string of a responsibility variable ratio, by the electronic power switch 61 of this pulse wave signal string control boost converter, make VD can rise to the current potential that can be complementary with distribution system voltage.
At last, adjust the maximum power tracing method that the mode of solar cell VD operates according to the variation of inverter output current, the synoptic diagram of the solar power system of its pair converter architecture, DC-DC converter circuit diagram and fixedly the controlling party block diagram of VD is also identical with Fig. 5 to Fig. 7 corresponding to Fig. 2 B and Fig. 4 B.
In sum, when knowing maximum power tracing method of the present invention and device, be by changing the output current amplitude of AC/DC converter, and the variation situation of observation solar cell VD, adjustment direction with decision current amplitude next time, or by changing the setting of solar cell VD, and the output current oscillation amplitude change situation of observing AC/DC converter, adjustment direction with decision solar cell VD setting next time, these two kinds of maximum power tracing methods all can be applied in the occasion of single switch and two converters simultaneously, to reach the purpose of the Maximum Power Output that sun-tracing can battery; The more important thing is, owing to needn't go to calculate the output power of solar power system veritably, therefore use the side circuit of maximum power tracing method of the present invention to dispose compared with prior art, is more simple and the saving cost.
The above is preferred embodiment of the present invention only, is not to be used for limiting practical range of the present invention.Be all those skilled in the art according to claim of the present invention do all as modify, all should be covered by in the scope of patent protection of the present invention.

Claims (15)

1. the maximum power tracing method of a solar power system, wherein this solar power system comprises a solar cell and an AC/DC converter at least, this maximum power tracing method comprises the following steps:
Adjust an output current of this AC/DC converter;
Observe the direct current output voltage variable quantity that a direct current output voltage of this solar cell is produced;
Equidirectionally adjust this output current once more with this VD variable quantity; And
Repeat above-mentioned steps in regular turn.
2. the maximum power tracing method of a solar power system, wherein this solar power system comprises a solar cell and an AC/DC converter at least, this maximum power tracing method comprises the following steps:
(a) provide an output current initial value of this AC/DC converter;
(b) measure the direct current output voltage initial value that this solar cell is produced according to this output current initial value;
(c) provide an output current reference value of this AC/DC converter, and make this solar power system under this output current reference value, operate a time interval;
(d) measure the direct current output voltage reference value that this solar cell is produced according to this output current reference value;
(e) relatively this VD reference value changes with respect to one of this VD initial value;
(f) change this output current reference value with this variation equidirectionally, and replace this VD initial value with this VD reference value; And
(g) repeating step (c)~(f).
3. the maximum power tracing device of a solar power system, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this solar cell and this AC/DC converter produce a direct current output voltage and an output current respectively, and this maximum power tracing device comprises:
One digital processing unit, be electrically connected on this solar cell and this AC/DC converter, this digital processing unit is in order to receiving this VD and this output current of feedback, and produces a control signal according to the direct current output voltage variable quantity that this VD produced; And
One pulse-width-modulation driver, be electrically connected on this AC/DC converter and this digital processing unit, this pulse-width-modulation driver produces a pulse-width signal according to this control signal, makes this AC/DC converter to adjust this output current with this VD variable quantity equidirectionally.
4. maximum power tracing device as claimed in claim 3 also has a storage capacitor, is connected in parallel in this solar cell and this AC/DC converter.
5. maximum power tracing device as claimed in claim 3, wherein this AC/DC converter is a DC/AC inverter.
6. maximum power tracing device as claimed in claim 3, wherein this digital processing unit comprises:
One voltage detection unit, the voltage of the distribution system that this solar power system that feeds back in order to reception connects is to produce a voltage detection signal;
One phase-locked loop control module is in order to receive this voltage detection signal, to produce a phase-locked loop signal;
One multiplier multiplies each other in order to the amplitude with this output current of this phase-locked loop signal and setting, to produce an output current reference signal; And
One comparer subtracts each other in order to this output current with this output current reference signal and feedback, to produce this control signal.
7. the maximum power tracing device of a solar power system, wherein this solar power system comprises a solar cell, a DC-DC converter and an AC/DC converter at least, and this solar cell, this DC-DC converter and this AC/DC converter produce one first VD, one second VD and an output current respectively, and this maximum power tracing device comprises:
One digital processing unit, be electrically connected on this solar cell, this DC-DC converter and this AC/DC converter, this digital processing unit is in order to receiving this second VD and this output current of feedback, and produces a control signal according to the direct current output voltage variable quantity that this second VD is produced; And
One pulse-width-modulation driver, be electrically connected on this DC-DC converter, this AC/DC converter and this digital processing unit, this pulse-width-modulation driver produces a pulse-width signal according to this control signal, makes this DC-DC converter produce this second VD and this AC/DC converter to adjust this output current amplitude with this VD variable quantity equidirectionally.
8. maximum power tracing device as claimed in claim 7, wherein this DC-DC converter is a boost converter, in order to receive this first VD, and boosted to produce this second VD, and this second VD is a fixed value, or has a fixed ratio with respect to this first VD.
9. maximum power tracing device as claimed in claim 7, also have one first storage capacitor and one second storage capacitor, wherein this first storage capacitor is connected in parallel in this solar cell and this DC-DC converter, and this second storage capacitor is connected in parallel in this DC-DC converter and this AC/DC converter.
10. the maximum power tracing method of a solar power system, wherein this solar power system comprises a solar cell and an AC/DC converter at least, this maximum power tracing method comprises the following steps:
Adjusting a direct current output voltage of this solar cell sets;
Observe the output current amplitude variations amount that an output current of this AC/DC converter is produced;
Equidirectionally adjusting this VD once more with this output current amplitude variations amount sets; And
Repeat above-mentioned steps in regular turn.
11. the maximum power tracing method of a solar power system, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this maximum power tracing method comprises the following steps:
(a) provide a direct current output voltage initial value of this solar cell;
(b) measure the output current amplitude initial value that this AC/DC converter is produced according to this VD initial value;
(c) adjust a direct current output voltage reference value of this solar cell, and make this solar power system under this VD reference value, operate a time interval;
(d) measure the output current amplitude reference value that this AC/DC converter is produced according to this VD reference value;
(e) relatively this output current amplitude reference value changes with respect to one of this output current amplitude initial value;
(f) change this VD reference value with this variation equidirectionally, and replace this output current amplitude initial value with this output current amplitude reference value after changing; And
(g) repeating step (c)~(f).
12. the maximum power tracing device of a solar power system, wherein this solar power system comprises a solar cell and an AC/DC converter at least, and this solar cell and this AC/DC converter produce a direct current output voltage and an output current respectively, and this maximum power tracing device comprises:
One digital processing unit, be electrically connected on this solar cell and this AC/DC converter, this VD and this output current that this digital processing unit feeds back in order to reception, and according to the living control signal of the output current amplitude variations volume production that this output current produced; And
One pulse-width-modulation driver, be electrically connected on this AC/DC converter and this digital processing unit, this pulse-width-modulation driver produces a pulse-width signal according to this control signal, makes this solar cell to adjust this VD with this output current amplitude variations amount equidirectionally.
13. maximum power tracing device as claimed in claim 12, wherein this digital processing unit comprises:
One voltage detection unit is in order to receive the voltage of the distribution system of feeding back that this solar power system connected, to produce a voltage detection signal;
One phase-locked loop control module is in order to receive this voltage detection signal, to produce a phase-locked loop signal;
One first comparer subtracts each other in order to this VD and a setting voltage that will feed back, to produce a direct current output voltage error signal;
One pi controller is in order to receive this VD error signal, to produce an output current amplitude signal;
One multiplier is in order to multiply each other this phase-locked loop signal and this output current amplitude signal, to produce an output current reference signal; And
One comparer subtracts each other in order to this output current with this output current reference signal and feedback, to produce this control signal.
14. the maximum power tracing device of a solar power system, wherein this solar power system comprises a solar cell, a DC-DC converter and an AC/DC converter at least, and this solar cell, this DC-DC converter and this AC/DC converter produce one first VD, one second VD and an output current respectively, and this maximum power tracing device comprises:
One digital processing unit, be electrically connected on this solar cell, this DC-DC converter and this AC/DC converter, this second VD and this output current that this digital processing unit feeds back in order to reception, and according to the living control signal of the output current amplitude variations volume production that this output current produced; And
One pulse-width-modulation driver, be electrically connected on this DC-DC converter, this AC/DC converter and this digital processing unit, this pulse-width-modulation driver produces a pulse-width signal according to this control signal, makes this DC-DC converter produce this second VD and this solar cell to adjust this first VD with this output current amplitude variations amount equidirectionally.
15. maximum power tracing device as claimed in claim 14, wherein this DC-DC converter is a boost converter, in order to receiving this first VD, and is boosted to produce this second VD.
CNA2003101205481A 2003-12-12 2003-12-12 Method for tracing maximum power for solar power system and equipment Pending CN1627225A (en)

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Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007087755A1 (en) * 2006-02-03 2007-08-09 Binxuan Yi Automatically tracing and control method and system of solar cell
CN100426175C (en) * 2006-09-25 2008-10-15 清华大学深圳研究生院 Mixed maximum power point-tracing control method of photovoltaic water-raising system
CN100463332C (en) * 2006-11-27 2009-02-18 孙民兴 Maximum power tracing method for solar power system and solar power device
CN101241377B (en) * 2007-08-24 2011-02-09 赵剑青 Photovoltaic grid-connected circuit topological structure
CN102566645A (en) * 2010-12-15 2012-07-11 上海电科电器科技有限公司 Maximum power control method of photovoltaic grid-connected inverter
CN102650889A (en) * 2011-02-24 2012-08-29 珠海格力节能环保制冷技术研究中心有限公司 Angle control system for solar cell panel
CN102770823A (en) * 2010-02-24 2012-11-07 Sma太阳能技术股份公司 Method for determining a maximum power point of photovoltaic generators
CN103069354A (en) * 2010-08-12 2013-04-24 Sma太阳能技术股份公司 Method for operation of a photovoltaic generator at an operating point of maximum power
US9829903B1 (en) 2016-08-15 2017-11-28 Industrial Technology Research Institute Power point tracking method and apparatus thereof
CN110262621A (en) * 2019-07-22 2019-09-20 重庆理工大学 A kind of solar maximum power collecting circuit and method for fast searching

Cited By (16)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2007087755A1 (en) * 2006-02-03 2007-08-09 Binxuan Yi Automatically tracing and control method and system of solar cell
CN100426175C (en) * 2006-09-25 2008-10-15 清华大学深圳研究生院 Mixed maximum power point-tracing control method of photovoltaic water-raising system
CN100463332C (en) * 2006-11-27 2009-02-18 孙民兴 Maximum power tracing method for solar power system and solar power device
CN101241377B (en) * 2007-08-24 2011-02-09 赵剑青 Photovoltaic grid-connected circuit topological structure
CN102770823B (en) * 2010-02-24 2014-08-27 Sma太阳能技术股份公司 Method for determining a maximum power point of photovoltaic generators
CN102770823A (en) * 2010-02-24 2012-11-07 Sma太阳能技术股份公司 Method for determining a maximum power point of photovoltaic generators
CN103069354B (en) * 2010-08-12 2014-12-10 Sma太阳能技术股份公司 Method for operation of a photovoltaic generator at an operating point of maximum power
CN103069354A (en) * 2010-08-12 2013-04-24 Sma太阳能技术股份公司 Method for operation of a photovoltaic generator at an operating point of maximum power
US8860358B2 (en) 2010-08-12 2014-10-14 Sma Solar Technology Ag Method for operation of a photovoltaic generator at an operating point of maximum power
CN102566645A (en) * 2010-12-15 2012-07-11 上海电科电器科技有限公司 Maximum power control method of photovoltaic grid-connected inverter
CN102566645B (en) * 2010-12-15 2014-08-27 上海电科电器科技有限公司 Maximum power control method of photovoltaic grid-connected inverter
CN102650889B (en) * 2011-02-24 2014-06-11 珠海格力节能环保制冷技术研究中心有限公司 Angle control system for solar cell panel
CN102650889A (en) * 2011-02-24 2012-08-29 珠海格力节能环保制冷技术研究中心有限公司 Angle control system for solar cell panel
US9829903B1 (en) 2016-08-15 2017-11-28 Industrial Technology Research Institute Power point tracking method and apparatus thereof
CN110262621A (en) * 2019-07-22 2019-09-20 重庆理工大学 A kind of solar maximum power collecting circuit and method for fast searching
CN110262621B (en) * 2019-07-22 2024-02-23 重庆理工大学 Solar maximum power collection circuit and quick search method

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