Background technology
Progress along with expanding economy, society; People propose increasingly high requirement to the energy; Seek new forms of energy and become the urgent problem that current mankind faces; And it is very huge to be radiated at tellurian solar energy, is radiated at tellurian solar energy, the consumption that just is enough to supply 1 year energy of global human in about 40 minutes.We can say that solar energy is really inexhaustible, the nexhaustible energy, and solar power generation is definitely clean, does not produce public hazards, is perfect energy sources so solar power generation is described as.
Obtain electric power from solar energy, need to carry out light-to-current inversion and realize through solar cell.It has following characteristics with other power supply electricity generating principles were different fully in the past: 1. do not have exhausted dangerous; 2. absolute clean (nuisanceless); 3. do not receive the restriction of resource distribution region; 4. can generate electricity nearby in electricity consumption place; 5. can source quality high; 6. the user is acceptant on the emotion; The time of 7. obtaining energy cost is short.Weak point is: 1. the Energy distribution density of irradiation is little, promptly will take huge area; 2. the same four seasons of the energy that obtain, reach and rain or shine wait meteorological condition relevant round the clock.But generally speaking, one flaw cannot mar the jade, and as new forms of energy, solar energy has very big advantage, therefore receives the attention of countries in the world.
When utilizing solar power generation, a plurality of optical-electric modules are electrically connected, optical-electric module electricity power are delivered to electrical network through one or more inverters.
Inverter is the equipment that direct current is converted to alternating current.Because solar cell and storage battery are DC power supplys, and load is when being AC load, and inverter is absolutely necessary.Inverter can be divided into independent operating inverter and combining inverter by operational mode.The independent operating inverter is used for the solar cell power generation system of independent operating, is independent electric.The solar cell power generation system that combining inverter is used to be incorporated into the power networks.Inverter can be divided into square-wave inverter and sinewave inverter by the output wave mode.The square-wave inverter circuit is simple, and cost is low, but harmonic component is big, generally is used for below several hectowatts and the system not high to harmonic requirement.The sinewave inverter cost is high, but goes for various loads.
Photovoltaic generating system is by solar cell array, batteries, and charging-discharging controller, inverter, AC power distribution cabinet/AC distribution panel, equipment such as solar tracking control system are formed.
When the weather at cloudy day, the output current of solar cell is extremely small, how to search out maximum power and exports inverter to, and people seek better method right.
The utility model content
In order to solve above problem, a kind of automatic searched devices and system that exports solar panel maximum power to inverter is provided.
The utility model discloses a kind of six grades of power searched devices, comprising:
Parameter imports the unit: the sunlight intensity of illumination parameter that imports search;
Parameter judging unit: import the unit with described parameter and link to each other, be used to judge whether described intensity of illumination parameter is lower than preset value;
Power adjustment unit links to each other with described power judging unit, is used for repeatedly reducing the numerical value of solar cell output current, and simultaneously, the solar cell power output repeatedly raises, until being increased to maximum power;
The power blockage unit links to each other with described power adjustment unit, is used to lock described maximum power and exports inverter to.
In the described six grades of power searched devices of the utility model, described repeatedly is 2~6 times.
In the described six grades of power searched devices of the utility model, described repeatedly is 6 times.
The utility model discloses a kind of system of six grades of power search; Comprise photocurrent generator; The inverter that links to each other with said photocurrent generator; With load and electrical network that described inverter links to each other respectively, with the control unit that described inverter and photocurrent generator link to each other, described control unit comprises above-mentioned a kind of six grades of power searched devices.
The power points of the maximum in the utility model real-time tracking solar panels has been given play to the maximum effect of solar panels, and voltage is high more, through maximum power tracing, can export maximum electric weight, thereby improves generating efficiency.
Implement a kind of six grades of power searched devices and the system of the utility model, have following beneficial technical effects:
Under the inadequate situation of illumination, track out maximum power output, improve generating efficiency.
Embodiment
By the technology contents, the structural feature that specify the utility model, realized purpose and effect, know clearly below in conjunction with execution mode and conjunction with figs. and give explanation.
By common practise, we can know: photovoltaic generation (Solar photovoltaics (PV)) is according to the photovoltaic effect principle, utilizes solar cell that solar energy is converted into electric energy.Independent use or generate electricity by way of merging two or more grid systems no matter be; Photovoltaic generating system mainly is made up of solar panel (assembly), controller and inverter three parts; They mainly are made up of electronic devices and components, do not relate to mechanical part, so; The very refining of photovoltaic generation equipment, the reliable and stable life-span is long, installation and maintenance are easy.Theoretically, photovoltaic power generation technology can be used for any occasion that needs power supply, goes up to spacecraft, down to domestic power supply, arrives the MW class power station greatly, and little of toy, photo-voltaic power supply can be ubiquitous.
Current strength; Under the constant situation of voltage, the generating voltage of the utility model method detecting real-time solar panels a lot of problems will not appear, if there is power points to follow the trail of; And follow the trail of the ceiling voltage current value, make system with the highest efficient to combining inverter to mains supply.
See also Fig. 1, a kind of method of six grades of power search comprises:
S1. import the sunlight intensity of illumination parameter of search;
S2. judge whether described intensity of illumination parameter is lower than preset value, if, get into step S3, if not, return step S1;
S3. reduce the numerical value of solar cell output current many times, simultaneously, the solar cell power output repeatedly raises, until being increased to maximum power;
S4. lock described maximum power and export inverter to.
In the weather at cloudy day, when the output current of solar cell is extremely small, then open 6 grades of power functions of search automatically.
Automatic Program is carried out six times power adjustment, and electric current is adjusted by being up under the minimum direction, and in self-adjusting process, power can strengthen power output to maximum power point from 0 as starting point, and restarting is at most 6 times, then the ingoing power lock-out state.
Please, be used to realize above-mentioned method, comprise with reference to Fig. 2, a kind of six grades of power searched devices:
Parameter imports unit 10, parameter judging unit 20, power adjustment unit 30, power blockage unit 40.
Parameter imports unit 10: the sunlight intensity of illumination parameter that imports search;
Parameter judging unit 20: import unit 10 with parameter and link to each other, be used to judge whether described intensity of illumination parameter is lower than preset value;
Power adjustment unit 30 links to each other with power judging unit 20, is used for repeatedly reducing the numerical value of solar cell output current, and simultaneously, the solar cell power output repeatedly raises, until being increased to maximum power;
Power blockage unit 40 links to each other with power adjustment unit 30, is used to lock described maximum power and exports inverter to.
Wherein, described repeatedly is 2~6 times, and described repeatedly is 6 times.
Solar panels are photocurrent generator (PV batteries), are a kind of semiconductor device, and its electrical characteristic is similar with diode, and still, the PV battery is power source rather than electrical load (diode then is), can become current source when it receives light (like sunlight) exposure.
Intensity of illumination and temperature all can influence the PV battery behavior.Electric current is directly proportional with intensity of illumination, and voltage equally also can change along with the fluctuation of intensity of illumination, and voltage receives the influence that the PV battery temperature changes more easily.
The power of PV battery can reduce with the reduction of intensity of illumination and/or the rising of temperature.Solar inverter could obtain ceiling capacity when the maximum power point output services of PV battery, can use the maximum power point control ring to reach this purpose, this control ring be also referred to as the maximum power point tracking device (Maximum Power Point Tracker, MPPT).In addition, the PV output voltage ripple at PV module terminals place must be enough little, so as its when near MPP, working the PV change in current not too large.
The amplitude of ripple voltage must be lower than 8.5% of MPP voltage just can reach 98% utilance, and for example, if the MPP voltage of certain PV module is 35V, then in order to keep 98% utilance, its voltage ripple amplitude should not surpass 3.0V.
Solar cell can be worked in the voltage and current scope of broad.Through the resistive load on the exposure battery is continued to increase to very high value from zero, can confirm MPP, that is to say that under this exposure intensity, load can be obtained maximum power from battery.
Practice confirms; High-quality monocrystaline silicon solar cell is 25 can produce the open circuit voltage of 0.6V when spending in its temperature; Under the sufficient situation of illumination; Battery temperature may be near 45 degree (even temperature be 25 degree), and maximum power (battery temperature is 45 degree) is 75 to 80% of an open circuit voltage at voltage usually, and electric current is to produce under 90% the condition of short circuit current.
See also the system of Fig. 3, a kind of six grades of power search; Comprise photocurrent generator 100; The inverter 110 that links to each other with photocurrent generator 100; With load 120 and electrical network 130 that inverter 110 links to each other respectively, with the control unit 135 that inverter 110 and photocurrent generator 100 link to each other respectively, control unit 135 comprises above-mentioned a kind of six grades of power searched devices.
Photocurrent generator 100 can be solar panel.
The native system course of work is: when the cloudy day starts native system; Constantly restarting of control unit 135 automatic tracking illumination electric generators 100; Maximum is restarted can reach 6 times; Constantly search maximum power point, be input to inverter 110 after having searched, carry out being transported to load 120 or electrical network 130 after direct current and the conversion that exchanges.
Implement a kind of six grades of power searched devices and the system of the utility model, have following beneficial technical effects:
Under the inadequate situation of illumination, track out maximum power output, improve generating efficiency.
Combine accompanying drawing that the embodiment of the utility model is described above; But the utility model is not limited to above-mentioned embodiment, and above-mentioned embodiment only is schematically, rather than restrictive; Those of ordinary skill in the art is under the enlightenment of the utility model; Not breaking away under the scope situation that the utility model aim and claim protect, also can make a lot of forms, these all belong to the row of the protection range of the utility model.