CN111756070A - Photovoltaic-temperature difference cogeneration device and maximum power point tracking algorithm thereof - Google Patents

Photovoltaic-temperature difference cogeneration device and maximum power point tracking algorithm thereof Download PDF

Info

Publication number
CN111756070A
CN111756070A CN202010688906.2A CN202010688906A CN111756070A CN 111756070 A CN111756070 A CN 111756070A CN 202010688906 A CN202010688906 A CN 202010688906A CN 111756070 A CN111756070 A CN 111756070A
Authority
CN
China
Prior art keywords
power
power generation
photovoltaic
output
thermoelectric
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010688906.2A
Other languages
Chinese (zh)
Inventor
梁秋艳
葛宜元
陈立冬
刘明普
孟庆祥
迟佳
于学亮
张宝岩
依红杰
陈�光
苏弘扬
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Jiamusi University
Original Assignee
Jiamusi University
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Jiamusi University filed Critical Jiamusi University
Priority to CN202010688906.2A priority Critical patent/CN111756070A/en
Publication of CN111756070A publication Critical patent/CN111756070A/en
Pending legal-status Critical Current

Links

Classifications

    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J3/00Circuit arrangements for ac mains or ac distribution networks
    • H02J3/38Arrangements for parallely feeding a single network by two or more generators, converters or transformers
    • H02J3/381Dispersed generators
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24SSOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S50/00Arrangements for controlling solar heat collectors
    • F24S50/20Arrangements for controlling solar heat collectors for tracking
    • GPHYSICS
    • G06COMPUTING; CALCULATING; COUNTING
    • G06NCOMPUTING ARRANGEMENTS BASED ON SPECIFIC COMPUTATIONAL MODELS
    • G06N7/00Computing arrangements based on specific mathematical models
    • G06N7/02Computing arrangements based on specific mathematical models using fuzzy logic
    • G06N7/023Learning or tuning the parameters of a fuzzy system
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02NELECTRIC MACHINES NOT OTHERWISE PROVIDED FOR
    • H02N11/00Generators or motors not provided for elsewhere; Alleged perpetua mobilia obtained by electric or magnetic means
    • H02N11/002Generators
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02SGENERATION OF ELECTRIC POWER BY CONVERSION OF INFRA-RED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S10/00PV power plants; Combinations of PV energy systems with other systems for the generation of electric power
    • H02S10/10PV power plants; Combinations of PV energy systems with other systems for the generation of electric power including a supplementary source of electric power, e.g. hybrid diesel-PV energy systems
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02SGENERATION OF ELECTRIC POWER BY CONVERSION OF INFRA-RED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S40/00Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
    • H02S40/20Optical components
    • H02S40/22Light-reflecting or light-concentrating means
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02SGENERATION OF ELECTRIC POWER BY CONVERSION OF INFRA-RED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S40/00Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
    • H02S40/40Thermal components
    • H02S40/42Cooling means
    • H02S40/425Cooling means using a gaseous or a liquid coolant, e.g. air flow ventilation, water circulation
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02SGENERATION OF ELECTRIC POWER BY CONVERSION OF INFRA-RED RADIATION, VISIBLE LIGHT OR ULTRAVIOLET LIGHT, e.g. USING PHOTOVOLTAIC [PV] MODULES
    • H02S40/00Components or accessories in combination with PV modules, not provided for in groups H02S10/00 - H02S30/00
    • H02S40/40Thermal components
    • H02S40/44Means to utilise heat energy, e.g. hybrid systems producing warm water and electricity at the same time
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24SSOLAR HEAT COLLECTORS; SOLAR HEAT SYSTEMS
    • F24S50/00Arrangements for controlling solar heat collectors
    • F24S50/20Arrangements for controlling solar heat collectors for tracking
    • F24S2050/25Calibration means; Methods for initial positioning of solar concentrators or solar receivers
    • HELECTRICITY
    • H02GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02JCIRCUIT ARRANGEMENTS OR SYSTEMS FOR SUPPLYING OR DISTRIBUTING ELECTRIC POWER; SYSTEMS FOR STORING ELECTRIC ENERGY
    • H02J2300/00Systems for supplying or distributing electric power characterised by decentralized, dispersed, or local generation
    • H02J2300/20The dispersed energy generation being of renewable origin
    • H02J2300/22The renewable source being solar energy
    • H02J2300/24The renewable source being solar energy of photovoltaic origin
    • H02J2300/26The renewable source being solar energy of photovoltaic origin involving maximum power point tracking control for photovoltaic sources
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/40Solar thermal energy, e.g. solar towers
    • Y02E10/47Mountings or tracking
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/50Photovoltaic [PV] energy
    • Y02E10/52PV systems with concentrators
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/50Photovoltaic [PV] energy
    • Y02E10/56Power conversion systems, e.g. maximum power point trackers
    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E10/00Energy generation through renewable energy sources
    • Y02E10/60Thermal-PV hybrids

Abstract

The invention discloses a photovoltaic-temperature difference cogeneration device, which comprises: a base; a fixed bracket disposed on the base; a drive mechanism provided on the fixed bracket; one end of the rotating shaft is connected with the power output end of the driving mechanism and can be rotatably supported on the fixed bracket; a condenser lens connected to the other end of the rotary shaft; the power generation mechanism is supported and arranged above the condenser lens; the cooling pool is communicated with the power generation mechanism; the water tank is communicated with the cooling pool and the power generation mechanism; a steam generator connected with the water tank; a battery electrically connected to the steam generator. The power generation mechanism is focused through the collecting lens, the height and the angle of the collecting lens can be adjusted, and the power generation efficiency is improved. The invention also provides a maximum power point tracking algorithm of the photovoltaic-temperature difference cogeneration device.

Description

Photovoltaic-temperature difference cogeneration device and maximum power point tracking algorithm thereof
Technical Field
The invention relates to a photovoltaic-temperature difference cogeneration device and a maximum power point tracking algorithm thereof, belonging to the field of energy utilization.
Background
The facility agriculture has the characteristics of high input and output, no pollution, sustainable development and the like. Greenhouse environment regulation and control equipment, irrigation devices, cultivation machinery and other equipment in facility agriculture all need to use electricity, and the current power utilization mode all adopts external power supply, can not solve the power consumption problem by oneself. In renewable energy power generation, photovoltaic power generation is a power generation mode with high utilization rate, but the power generation efficiency of the photovoltaic power generation is reduced along with the increase of the back surface temperature of a photovoltaic panel.
The thermoelectric power generation technology utilizes the Seebeck effect of a semiconductor material, and a device manufactured according to the principle is small and exquisite, convenient to carry, free of pollution and noise, and capable of overhauling and replacing damaged devices at any time. The existing solar photovoltaic-temperature difference device does not have a light condensation function, a maximum power point tracking function, a sun tracking function and the functions of generating capacity, temperature difference value and the like of a real-time monitoring device, and the solar utilization rate and the generating efficiency are lower.
Under different sunlight irradiation intensities and temperature fields, the photovoltaic cell and the thermoelectric generation assembly have different and unique maximum power points, and in order to improve the operation efficiency of the device, the optimal working state of the photovoltaic cell and the thermoelectric generation assembly needs to be searched through a control algorithm, so that the maximum power output of the photovoltaic-thermoelectric cogeneration device is realized, and the purpose of fully utilizing solar energy is achieved.
Disclosure of Invention
The photovoltaic-temperature difference cogeneration device is designed and developed, and the power generation mechanism is condensed by the condenser lens, the height and the angle of the condenser lens can be adjusted, and the power generation efficiency is improved.
The invention also designs and develops a maximum power point tracking algorithm of the photovoltaic-thermoelectric cogeneration device, and the maximum power point of the device is optimally tracked by a disturbance observation method and a variable universe fuzzy PID control fusion algorithm, so that the output power of the device and the utilization rate of solar energy are improved.
The technical scheme provided by the invention is as follows:
a photovoltaic-thermoelectric cogeneration apparatus, comprising:
a base;
a fixed bracket disposed on the base;
a drive mechanism provided on the fixed bracket;
one end of the rotating shaft is connected with the power output end of the driving mechanism and can be rotatably supported on the fixed bracket;
a condenser lens connected to the other end of the rotary shaft;
the power generation mechanism is supported and arranged above the condenser lens;
the cooling pool is communicated with the power generation mechanism;
the water tank is communicated with the cooling pool and the power generation mechanism;
a steam generator connected with the water tank;
a battery electrically connected to the steam generator.
Preferably, the power generation mechanism includes:
the two solar photovoltaic panels are respectively and oppositely arranged at the top and the bottom of the power generation mechanism, each solar photovoltaic panel comprises a front surface and a back surface, and the back surfaces are oppositely arranged;
the hot ends of the two temperature difference power generation components are respectively connected with the back surface of the solar photovoltaic panel;
at least two condenser tubes disposed between the two thermoelectric generation assemblies.
Preferably, heat-conducting silica gel is filled between the thermoelectric generation assembly and the solar photovoltaic panel.
Preferably, the power generation mechanism further includes:
a plurality of temperature sensors disposed between the condensation duct and the thermoelectric generation assembly.
Preferably, one end of the condensation pipe is communicated with one end of the cooling pool, and the other end of the condensation pipe is communicated with the other end of the cooling pool after passing through the water tank.
Preferably, the method further comprises the following steps:
a steam conduit for communicating the water tank with the steam generator.
Preferably, the method further comprises the following steps:
and the heat preservation pipe is arranged outside the condensation pipe.
Preferably, the method further comprises the following steps:
and the central control system is electrically connected with the solar photovoltaic panel, the temperature difference power generation assembly, the plurality of temperature sensors, the steam generator and the storage battery respectively.
A maximum power point tracking algorithm for a photovoltaic-thermoelectric cogeneration apparatus, comprising:
the fixed value of the output voltage is set to be 0.75UmDetermining the maximum output power P of the power generating mechanismm
Collecting the voltage U and the current I of a measuring point, and calculating the output power P of the measuring point;
when P is more than or equal to PmAnd U is less than 0.75UmAt that time, U is corrected by fuzzy control so that P ^ Pm
When P < PmAnd U > 0.75UmAt that time, U is corrected by fuzzy control so that P ^ Pm
Dividing the deviation e (k) of the output voltage and the deviation change rate ec (k) of the output voltage into five grades, and outputting the quantity delta D of the change of the circuit duty ratio as the input quantity of the fuzzy PID controller;
when e (k) is 0, the measuring point is the working point of the maximum output power;
wherein, P (k) is the power value at the k-th sampling, P (k-1) is the power value at the k-1-th sampling, I (k) is the current value at the k-th sampling, and I (k-1) is the current value at the k-1-th sampling.
Preferably, the input quantity and the output quantity of the fuzzy PID are set in a variable domain,
the universe of discourse for the input variables is: xi(xi)=[-αi(xi)E,αi(xi)E];
The universe of discourse for the output variables is: y (y) [ - β (y) D, β (y) D ];
wherein, αi(xi) And β (y) is the scale factor of the domain of discourse, xiIs the input variable, y is the output variable, E is the maximum value of the input variable, and D is the maximum value of the output variable.
The invention has the following beneficial effects: the invention combines a solar light-gathering technology, a photovoltaic power generation technology and a temperature difference power generation technology together, provides a light-gathering solar photovoltaic-temperature difference cogeneration device suitable for facility agriculture, realizes the step utilization of energy and achieves the purpose of cogeneration; the invention provides an intelligent optimization control algorithm integrating a disturbance observation method and variable universe fuzzy PID control, which tracks (MPPT) the maximum power point of a device and improves the output power of the device; the mixed tracking method combines the sight-day track tracking and the photoelectric automatic tracking, and improves the utilization rate of solar energy. In addition, the device can realize self-power supply, the system can realize self-sufficiency by adopting a method of additionally installing a storage battery, and the performance index of the device is measured and controlled by utilizing the data of the single chip microcomputer detection system and through a feedback system of the device.
The invention adopts a fixed strip-shaped mirror reflection condenser (FMSC) to collect more sunlight for the solar photovoltaic panel, thereby improving the output power. The photovoltaic panel back surface is provided with the thermoelectric generation assembly, the photovoltaic panel back surface temperature is used as a heat source of the thermoelectric generation assembly, the photoelectric conversion efficiency is reduced due to the fact that the photovoltaic panel back surface temperature rises, meanwhile, the thermoelectric generation assembly can also emit electric energy, and the stepped utilization of energy is achieved. The heat taken away by the temperature difference power generation assembly cooling system can be continuously used, and the purpose of cogeneration is achieved.
Drawings
Fig. 1 is a schematic structural view of a photovoltaic-thermoelectric cogeneration apparatus according to the present invention.
Fig. 2 is a schematic structural diagram of the central control system according to the present invention.
Fig. 3 is a schematic structural diagram of the power generation mechanism according to the present invention.
FIG. 4 is a control flow chart of the disturbance-fuzzy fusion optimization algorithm according to the present invention.
FIG. 5 is a flowchart illustrating the tracking of the apparent day according to the present invention.
FIG. 6 is a graph of membership functions according to the present invention.
Detailed Description
The present invention is further described in detail below with reference to the attached drawings so that those skilled in the art can implement the invention by referring to the description text.
As shown in fig. 1 to 6, the present invention provides a photovoltaic-thermoelectric cogeneration apparatus, comprising: the solar water heater comprises a base 100, a rotating shaft 200, a first driving motor 210a, a second driving motor 210b, a collecting mirror 400, a power generation mechanism, a first condensation pipe 530a, a second condensation pipe 530b, a cooling tank 600, a water tank 700, a steam generator 900 and a storage battery 910.
As shown in fig. 1, the base 200 is horizontally disposed on the ground, the fixed bracket 110 is disposed on the base 200, the rotating shaft 200 is supported on the fixed bracket 110, one end of the rotating shaft 200 is connected to a power output end of a first driving motor 210a, the two driving motors are parallel to the base, and the first driving motor 210a is located below the rotating shaft and is responsible for regulating and controlling a direction based on a plane perpendicular to the rotating shaft; the second driving motor 210b is located above the rotation axis and is responsible for regulating and controlling the direction of the reference of the horizontal plane of the rotation axis, the collecting mirror 400 is supported and arranged at the other end of the rotation axis 200, the power generation mechanism is supported and arranged above the collecting mirror 400, the cooling tank 600 is communicated with the power generation mechanism through a condensation pipe, the water tank 700 is communicated with the cooling tank 600, and the steam engine 900 is simultaneously connected with the water tank 700 and the storage battery 910.
The two ends of the collecting mirror 400 are respectively provided with a first photoelectric sensor 310a and a second photoelectric sensor 310b for collecting illumination intensity information and feeding back the illumination intensity information to the central control system, the collecting mirror 400 is used for collecting light for the power generation mechanism, and the central control system is simultaneously electrically connected with the first driving motor 210a, the second driving motor 210b, the collecting mirror 400, the power generation mechanism, the first condensation pipe 530a, the second condensation pipe 530b, the cooling tank 600, the water tank 700, the steam generator 900 and the storage battery 910.
As shown in fig. 3, the whole power generation mechanism is in a strip-shaped symmetrical structure, and includes: the solar photovoltaic system comprises two solar photovoltaic panels 510a and 510b, two temperature difference power generation assemblies 520a and 520b and two condensation pipes 530a and 530b, wherein the two solar photovoltaic panels 510a and 510b comprise front surfaces and back surfaces, the back surfaces of the two solar photovoltaic panels 510a and 510b are oppositely arranged, and the two temperature difference power generation assemblies 520a and 520b are respectively arranged on the back surfaces of the two solar photovoltaic panels 510a and 510b in a matching mode and used for collecting light energy to generate power; heat-conducting silica gel is filled between each temperature difference power generation assembly and the solar photovoltaic panel, one end of each of the two condensation pipes 530a and 530b is connected with one end of the cooling pool 600, and the other end of each of the two condensation pipes is communicated with the other end of the cooling pool 600 after passing through the space between the two temperature difference power generation assemblies and the water tank 700; two air pumps 550a and 550b are respectively arranged between the two condensation pipes 530a and 530b and the water tank 600 in a matching manner, and a plurality of temperature sensors 540 are arranged between the condensation pipes and the temperature difference components; the hot ends of the two thermoelectric generation assemblies 520a and 520b are respectively arranged on the back surfaces of the two solar photovoltaic panels 510a and 510b in a matching manner.
As shown in fig. 2, the central control system plays a role in collecting, transmitting and feeding back information in the equipment in the device, the system realizes remote detection and information collection, the control system is connected near the facility and serves as a control circuit of the facility, data can be transmitted to a remote PC through an additional sensor network, and the central control system is placed in the power distribution cabinet in consideration of the influence of the external environment. The central control system comprises a first control switch 1011, a second control switch 1012, a third control switch 1013, a fourth control switch 1014, a temperature display key 1021, a current display key 1022, a light illumination display key 1023, a voltage display key 1024, a power display key 1025 and an alarm display key 1026, wherein the first control switch 1011 and the second control switch 1012 are responsible for controlling the switching of the whole device, and the second control switch and the third control switch are responsible for controlling the on-off between the storage battery 910 and the device; the temperature display key 1021, the current display key 1022, the illuminance display key 1023, the voltage display key 1024, the power display key 1025, and the alarm display key 1026 respectively display the temperature of the thermoelectric generation element in the device, and alarm information is generated when the current, the voltage, the power output by the device, the illuminance received by the device, and the temperature of the thermoelectric generation element are too high.
The plurality of temperature sensors 540 need to be used in combination, and the measured temperature information is fed back to the central control system.
One end of the steam guide pipe 800 is communicated with the water tank 700, and the other end is connected with the generator 900, so that the hot steam in the water tank can be delivered to the steam generator 900 to generate electricity. A circulating structure is formed between the cooling pool 600 and the water tank 700 through the two condensation pipes 530a and 530b, so that the cooling liquid can be recycled, the heat preservation pipes 560a and 560b are respectively arranged outside the two condensation pipes 530a and 530b in a matching manner, and heat preservation materials are filled between the condensation pipes and the heat preservation pipes, so that heat in the cooling liquid is prevented from losing.
The fixed strip-shaped mirror reflection condenser is adopted to collect more sunlight for the solar photovoltaic panel, so that the output power is improved. The photovoltaic panel back surface is provided with the thermoelectric generation assembly, the photovoltaic panel back surface temperature is used as a heat source of the thermoelectric generation assembly, the photoelectric conversion efficiency is reduced due to the fact that the photovoltaic panel back surface temperature rises, meanwhile, the thermoelectric generation assembly can also emit electric energy, and the stepped utilization of energy is achieved. The heat taken away by the cooling system of the thermoelectric generation assembly can be continuously used to achieve the purpose of cogeneration
The invention also provides a maximum power point tracking algorithm of the photovoltaic-thermoelectric cogeneration device, which is used for carrying out optimizing tracking on the maximum power point of the device through a fuzzy PID algorithm so as to improve the output power of the device and the utilization rate of solar energy, and comprises the following steps:
the fixed value of the output voltage is set to be 0.75UmDetermining the maximum output power P of the power generating mechanismm
Collecting the voltage U and the current I of a measuring point, and calculating the output power P of the measuring point;
when P is more than or equal to PmAnd U is less than 0.75UmAt that time, U is corrected by fuzzy control so that P ^ Pm
When P < PmAnd U > 0.75UmAt that time, U is corrected by fuzzy control so that P ^ Pm
Dividing the deviation e (k) of the output voltage and the deviation change rate ec (k) of the output voltage into five grades, and outputting the quantity delta D of the change of the circuit duty ratio as the input quantity of the fuzzy PID controller;
wherein the content of the first and second substances,
when e (k) is 0, the measuring point is the working point of the maximum output power;
wherein, P (k) is the power value at the k-th sampling, P (k-1) is the power value at the k-1-th sampling, I (k) is the current value at the k-th sampling, and I (k-1) is the current value at the k-1-th sampling.
The algorithm designs the fuzzy rule of the controller by utilizing the tracking principle of a disturbance observation method, so that the universality of the controller is improved, meanwhile, on the premise that the quantity of the fuzzy rule is unchanged, the range of an initial domain is adjusted by adding a domain expansion factor, the combination of the initial domain and the expansion factor can ensure that the range of the initial domain is contracted along with the reduction of errors, namely, the control rule is indirectly increased, so that the membership function of each linguistic value on the domain is correspondingly contracted or expanded, the control precision and the response speed of the system can be greatly improved, the stability and the reliability of the system are improved, and the output power of the device is improved.
The intelligent optimization control algorithm integrating the disturbance observation method and the variable universe fuzzy PID control has the following specific processes:
the disturbance observation method is a relatively mature self-optimizing control algorithm, the output power and the voltage are respectively assumed to be P, U, the maximum power point is Pm, the power difference delta P is Pn-Pn-1, the disturbance voltage delta U is applied, and the specific control process of the disturbance observation method MPPT is as follows:
(1) adding disturbance voltage delta U + and if delta P is larger than 0, indicating that the working point moves from point A to point B, the current point is on the left side of Pm, and the original disturbance direction should be maintained at the moment, and continuing to increase the voltage;
(2) adding disturbance voltage delta U + and if delta P is less than 0, indicating that the working point is from a point D to a point C, and the current point is on the right side of Pm, and at the moment, reversing the original disturbance and reducing the voltage;
(3) adding disturbance voltage delta U-, if delta P is more than 0, indicating that the working point is from a point C to a point D, the current point is on the right side of Pm, and the original disturbance direction should be maintained at the moment, and reducing the voltage;
(4) applying disturbance voltage delta U-, if delta P is less than 0, indicating that the working point is from a point B to a point A, and the current point is on the left side of Pm, and at the moment, reversing the original disturbance and increasing the voltage;
however, the algorithm only blindly tends to the maximum power point and repeatedly oscillates at the maximum power point, the stability is poor, redundant power loss is caused, and a misjudgment phenomenon may be caused when the environmental condition is suddenly changed. Therefore, the invention provides an intelligent optimization control algorithm integrating the disturbance observation method and the variable universe fuzzy PID control, which can improve the control precision and response speed of the system to a great extent, improve the stability and reliability of the system and improve the output power of the device.
The basic idea of realizing MPPT through fuzzy control is that firstly, the output characteristics of a photovoltaic cell are analyzed, secondly, the rule is established according to the control logic of MPPT, and finally, the output control quantity is clarified to obtain the regulating quantity of the duty ratio, so that a DC/DC converter is controlled to realize maximum power point tracking. Because the method has good robustness and quick response, under the operating environment formed by interweaving the control algorithm and the environmental parameters, the fuzzy control method has stronger local search capability, can stably follow near the maximum power point, and is beneficial to system stability. In the invention, a disturbance observation method is taken as a primary optimization searching strategy from the global consideration of the searching process, and once the optimization step length is folded back, the local searching strategy is immediately entered. The fuzzy control with good robustness is introduced into the local search strategy, the balance between search space exploration and development can be kept, namely, the disturbance observation method and the fuzzy control method are complemented to realize respective advantages in the whole search process, respective defects are avoided, and meanwhile, speed and stable win-win optimization are obtained.
The fusion optimization algorithm firstly fixes the output voltage of the photovoltaic cell at 0.75Um through the transformation of the photovoltaic cell and the load impedance, so that the working point of the photovoltaic cell is rapidly moved to the position near the maximum power point and is the left side, and after the initialization is finished, the system immediately enters the preliminary optimization. And taking a disturbance observation method as an initial stage of optimization, continuously disturbing the output voltage of the photovoltaic cell, comparing the output voltage with the sampling power at the previous moment, judging the working state point of the photovoltaic cell on the photovoltaic characteristic, and continuously approaching the working point to the maximum power point through the disturbance of the voltage step length. When the system just enters a preliminary optimization stage, the working point of the photovoltaic cell is on the left side of the maximum power point, the preliminary optimization state is that a positive step length is applied and disturbance is maintained, but once the working point passes the maximum power point, a negative step length is applied and the disturbance direction is changed, namely, the system enters a repeated oscillation state on two sides of the maximum power point. In the invention, in order to avoid the problem of repeated oscillation of a disturbance observation method, once the working point of the photovoltaic cell enters the right side of the maximum power point, the working point immediately enters a local search strategy of variable-domain fuzzy PID control.
(1) Fuzzy input and output quantity determination
In the process of realizing MPPT control, the fuzzy control system calculates the collected current value and voltage value output by the photovoltaic cell to obtain the power value of the current working point, then judges the position relation between the current working point and the maximum power point, and automatically corrects the voltage value of the working point to enable the current working point to approach the maximum power point. And taking the deviation e and the deviation change rate ec as the input of a fuzzy PID controller, and defining the change quantity Delta D of the duty ratio of a Boost circuit as the output variable of the fuzzy logic controller. Defining:
ec(k)=e(k)-e(k-1) (2);
in the above formula, P (k) and I (k) represent the k-th sampling value of the output power of the photovoltaic cell and the k-th sampling value of the output current, and the previous sampling value is represented by k-1. When e (k) is 0, it indicates that the system has tracked the target power point, i.e., the maximum power point.
Design of variable universe of discourse Xi=[-E,E](i-1, 2, 3 … n) is an input variable xiOf Y [ -D, D]An initial universe of discourse for the output variable y; the variable domain is the discourse domain XiAnd Y can be respectively based on the variable xiAdjusted in response to changes in y, by introducing a scaling factor affected by the fuzzy input to effect dynamic changes in the universe of discourse, i.e.
Xi(xi)=[-αi(xi)Eii(xi)Ei](3);
Y(y)=[-β(y)D,β(y)D](4);
Wherein, αi(xi) And β (y) is the scale factor of the domain of discourse, xiTo be transportedThe input variable, y the output variable, E the maximum value of the input variable, and D the maximum value of the output variable.
When the fuzzy controller works, the e and ec which are used as fuzzy input are continuously reduced along with the realization of tracking, and the expansion factor is reduced along with the reduction of the e and ec, so that the range of the domain of discourse is contracted, the contraction of the domain of discourse is equivalent to an increasing rule, and the control precision is improved. Meanwhile, due to the scaling factor, the change of the initial domain of discourse can not influence the control effect any more, so that the selection precision of the initial domain of discourse is reduced.
(3) Determination of fuzzy sets and membership functions
As shown in fig. 6, due to the introduction of the scaling factor, the form of the membership function under the variable domain and the division of the domain have a limited influence on the control effect, and the fuzzy set input and output by the fuzzy controller can be defined as: negative Big (NB), Negative Small (NS), zero (Z), Positive Small (PS), Positive Big (PB)5 fuzzy subsets, whose membership function form selects a triangular function, evenly distributed in the domain of discourse, as shown in fig. 3.
(4) Determination of fuzzy rules
1) If e (k) >0, the operating point at time k is left of the Maximum Power Point (MPP). At this time, if ec (k) >0, the voltage is reduced compared with the operating point voltage at the previous moment, that is, the operating point voltage is moved away from the MPP, and a large step of reduction duty ratio is needed to increase the voltage, so that the current operating point is moved towards the MPP; if ec (k) <0, the operating point voltage at this moment is increased compared with the previous moment, namely, the operating point voltage is moved to the direction close to the MPP without changing the duty ratio;
2) if e (k) <0, the operating point at time k is known to be on the right side of the MPP. At this time, if ec (k) >0, the operating point voltage at this moment is reduced compared with the previous moment, that is, the operating point voltage is moved to the direction close to the MPP, and the duty ratio does not need to be changed; if ec (k) <0, the voltage of the operating point at the moment is increased compared with the voltage of the operating point at the previous moment, namely the operating point is moved to the direction far away from the MPP, and the voltage is reduced by increasing the duty ratio with large steps, so that the current operating point is moved to the direction close to the MPP;
3) if e (k) is 0 and ec (k) is 0, the operating point at time k is the maximum power point MPP.
According to the above rules, the fuzzy control rules shown in table 1 are established.
TABLE 1 fuzzy control rules Table
The device is added with a photoelectric tracking method on the basis of a sun-looking running track tracking method to finely adjust the angle of a system device, and sets tracking times and tracking intervals in different time periods through the study on the sun running track and the sun irradiance in one year, thereby achieving the purpose of predicting and tracking. The system device is subjected to angle fine adjustment by adopting a photoelectric tracking method, four independent photoelectric sensors (PZ-V/M) are respectively arranged on four edges of a fixed strip-shaped reflecting condenser (FMSC), wherein the upper sensor and the lower sensor are used for adjusting the altitude angle, and the left sensor and the right sensor are used for adjusting the azimuth angle. In a sunny day, a photoelectric tracking method can be normally used for tracking the apparent-day running track, but under the condition of shade, the difference value of photoelectric signals transmitted back by the photoelectric sensor is large, so that the system enters a shade-shading tracking state: the system enters an inherent program in the tracking of the apparent day running track to track the sun. Since the rate of change of the azimuth and elevation angles of the sun are different, the following description of the relevant quantities is made in connection with the position of the sun:
solar declination angle: the angle between the sun rays and the equatorial plane, known as the declination angle of the sun, is commonly expressed as 23.45sin [ 360/(284 + n)365 ]; where n is the number of days of a year, leap year n is 366 or year n is 365
Solar time angle: the solar time angle is the angle related to time, denoted as omega, the sun
Rotating the meridian angle of 15 degrees every hour, wherein omega is 0 at noon; negative in the morning and complete in the afternoon; the formula is ω ═ 12 × 15 °
In the tracking system, the used sun is generally replaced by a flat sun, and the influence caused by longitude is generally not considered.
Solar altitude: the solar altitude is simply referred to as the solar altitude (actually, the angle). Expressed by alpha, the calculation formula is alpha as arcsin (sinsin psi + cos psi coscos omega)
Where ψ is the local latitude.
Solar azimuth angle: the solar azimuth is the angle measured clockwise from north along the horizon. Expressed by gamma, the formula is gamma as arcsin (cossin omega/cos alpha)
The data collected under normal conditions is calculated as
The coordinate system at noon is set as an initial coordinate system, the movement on the X axis is Ex, the movement on the X axis is Ey, and feedback signals Ea, Eb, Ex and Ex of the four sensors are arranged up, down, left and right. Then
Ex=Ea-Eb/[(Ea+Eb)/2];
Ey=Ec-Ed/[(Ea+Eb)/2];
So according to the data feedback; setting a clock signal in the singlechip to ensure that the rotation rates of the stepping motors in a rated time period are different; the system obtains more solar radiation energy, the tracking precision is improved, and the heat collection efficiency is improved.
While embodiments of the invention have been described above, it is not limited to the applications set forth in the description and the embodiments, which are fully applicable in various fields of endeavor to which the invention pertains, and further modifications may readily be made by those skilled in the art, it being understood that the invention is not limited to the details shown and described herein without departing from the general concept defined by the appended claims and their equivalents.

Claims (10)

1. A photovoltaic-thermoelectric cogeneration apparatus, comprising:
a base;
a fixed bracket disposed on the base;
a drive mechanism provided on the fixed bracket;
one end of the rotating shaft is connected with the power output end of the driving mechanism and can be rotatably supported on the fixed bracket;
a condenser lens connected to the other end of the rotary shaft;
the power generation mechanism is supported and arranged above the condenser lens;
the cooling pool is communicated with the power generation mechanism;
the water tank is communicated with the cooling pool and the power generation mechanism;
a steam generator connected with the water tank;
a battery electrically connected to the steam generator.
2. The pv-thermoelectric cogeneration apparatus according to claim 1, wherein said power generation mechanism comprises:
the two solar photovoltaic panels are respectively and oppositely arranged at the top and the bottom of the power generation mechanism, each solar photovoltaic panel comprises a front surface and a back surface, and the back surfaces are oppositely arranged;
the hot ends of the two temperature difference power generation components are respectively connected with the back surface of the solar photovoltaic panel;
at least two condenser tubes disposed between the two thermoelectric generation assemblies.
3. The pv-thermoelectric cogeneration apparatus according to claim 2, wherein a heat-conducting silica gel is further filled between the thermoelectric generation module and the solar pv panel.
4. The pv-thermoelectric cogeneration apparatus according to claim 3, wherein said power generation mechanism further comprises:
a plurality of temperature sensors disposed between the condensation duct and the thermoelectric generation assembly.
5. The PV-thermoelectric cogeneration apparatus according to claim 4, wherein one end of the condensation pipe is communicated with one end of the cooling tank, and the other end of the condensation pipe is communicated with the other end of the cooling tank after passing through the water tank.
6. The photovoltaic-thermoelectric cogeneration apparatus of claim 5, further comprising:
a steam conduit for communicating the water tank with the steam generator.
7. The photovoltaic-thermoelectric cogeneration apparatus of claim 6, further comprising:
and the heat preservation pipe is arranged outside the condensation pipe.
8. The photovoltaic-thermoelectric cogeneration apparatus of claim 7, further comprising:
and the central control system is electrically connected with the solar photovoltaic panel, the temperature difference power generation assembly, the plurality of temperature sensors, the steam generator and the storage battery respectively.
9. A maximum power point tracking algorithm for a photovoltaic-thermoelectric cogeneration apparatus, comprising:
the fixed value of the output voltage is set to be 0.75UmDetermining the maximum output power P of the power generating mechanismm
Collecting the voltage U and the current I of a measuring point, and calculating the output power P of the measuring point;
when P is more than or equal to PmAnd U is less than 0.75UmAt that time, U is corrected by fuzzy control so that P ^ Pm
When P < PmAnd U > 0.75UmAt that time, U is corrected by fuzzy control so that P ^ Pm
Dividing the deviation e (k) of the output voltage and the deviation change rate ec (k) of the output voltage into five grades, and outputting the quantity delta D of the change of the circuit duty ratio as the input quantity of the fuzzy PID controller;
ec(k)=e(k)-e(k-1);
when e (k) is 0, the measuring point is the working point of the maximum output power;
wherein, P (k) is the power value at the k-th sampling, P (k-1) is the power value at the k-1-th sampling, I (k) is the current value at the k-th sampling, and I (k-1) is the current value at the k-1-th sampling.
10. The maximum power point tracking algorithm for a PV-TCHP device of claim 9, wherein the input and output of the fuzzy PID are both set to a domain of variation,
the universe of discourse for the input variables is: xi(xi)=[-αi(xi)E,αi(xi)E];
The universe of discourse for the output variables is: y (y) [ - β (y) D, β (y) D ];
wherein, αi(xi) And β (y) is the scale factor of the domain of discourse, xiIs the input variable, y is the output variable, E is the maximum value of the input variable, and D is the maximum value of the output variable.
CN202010688906.2A 2020-07-17 2020-07-17 Photovoltaic-temperature difference cogeneration device and maximum power point tracking algorithm thereof Pending CN111756070A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010688906.2A CN111756070A (en) 2020-07-17 2020-07-17 Photovoltaic-temperature difference cogeneration device and maximum power point tracking algorithm thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010688906.2A CN111756070A (en) 2020-07-17 2020-07-17 Photovoltaic-temperature difference cogeneration device and maximum power point tracking algorithm thereof

Publications (1)

Publication Number Publication Date
CN111756070A true CN111756070A (en) 2020-10-09

Family

ID=72711556

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010688906.2A Pending CN111756070A (en) 2020-07-17 2020-07-17 Photovoltaic-temperature difference cogeneration device and maximum power point tracking algorithm thereof

Country Status (1)

Country Link
CN (1) CN111756070A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113131862A (en) * 2021-03-10 2021-07-16 俞林杰 A light energy utilization rate hoisting device for solar cell panel

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105391376A (en) * 2015-12-31 2016-03-09 东北农业大学 Solar photovoltaic temperature difference combined power generation device
CN109945512A (en) * 2019-04-04 2019-06-28 南京林业大学 A kind of efficient photovoltaic and photothermal integrated system

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN105391376A (en) * 2015-12-31 2016-03-09 东北农业大学 Solar photovoltaic temperature difference combined power generation device
CN109945512A (en) * 2019-04-04 2019-06-28 南京林业大学 A kind of efficient photovoltaic and photothermal integrated system

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
冯广焕: "聚光式太阳能光伏/温差电热联产系统设计与分析", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 *
孔飞: "光伏发电系统最大功率点跟踪控制策略研究", 《中国优秀硕士学位论文全文数据库 工程科技Ⅱ辑》 *
梁秋艳: "聚光太阳能温差发电关键技术及热电性能机理研究", 《中国博士学位论文全文数据库 工程科技Ⅱ辑》 *
王立舒等: "基于混合策略的光伏MPPT算法优化控制", 《太阳能学报》 *

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN113131862A (en) * 2021-03-10 2021-07-16 俞林杰 A light energy utilization rate hoisting device for solar cell panel

Similar Documents

Publication Publication Date Title
Nadia et al. Advances in solar photovoltaic tracking systems: A review
Sumathi et al. Solar tracking methods to maximize PV system output–A review of the methods adopted in recent decade
Helwa et al. Maximum collectable solar energy by different solar tracking systems
Sarker et al. Design, fabrication and experimental study of a novel two-axis sun tracker
Azizi et al. Design and manufacturing of a high-precision sun tracking system based on image processing
CN111756070A (en) Photovoltaic-temperature difference cogeneration device and maximum power point tracking algorithm thereof
CN105955319B (en) A kind of sun tracker control system based on inverter output power
Whavale et al. A review of Adaptive solar tracking for performance enhancement of solar power plant
Verma et al. A Review Paper on Solar Tracking System for Photovoltaic Power Plant
Echendu et al. Design and Implementation of an Off-Grid Solar Tracker Control System using Proteus Version 8.1
Parveen et al. IoT based solar tracking system for efficient power generation
CN106292743A (en) Solar double-shaft auto-tracking system and tracking
CN106026882A (en) Group control system of intelligent sun tracker
Ghosh et al. Grid-tie rooftop solar system using enhanced utilization of solar energy
Choi et al. Development of a novel tracking system for photovoltaic efficiency in low level radiation
Debbarma et al. A Review on Solar Tracking System and Their Classification
Alboteanu et al. Positioning systems for solar panels placed in isolated areas
Naveen et al. A novel scheme for dynamically tracking solar panel
Brisha Enhancement of Power Generation for PV Systems Using Dynamic Tracking System
Karwande et al. Automatic watering system with efficient sun tracking solar plate
Dutta et al. Optimal selection of solar tracking system in India: A Review
Abou Saltouha et al. Microcontroller-based sun tracking system for PV module
Kumar et al. Solar probe based autonomous solar tracker system-A review
Ahmad et al. Effective and Low-Cost Arduino based Dual-Axis Solar Tracker
Verma et al. Real-Time Solar Tracking System with GPS

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination