CN110571845A - A photovoltaic grid-connected power generation system - Google Patents

Abstract

The invention discloses a photovoltaic grid-connected power generation system, comprising a current processing system and a plurality of integrated photoelectric conversion components, each integrated photoelectric conversion component includes a photovoltaic assembly, a main controller and a battery integrated on a bracket, the photovoltaic assembly A maximum power tracker is connected with the main controller, a charge and discharge controller is connected between the battery and the main controller, the current processing system includes a DC combiner box and an AC power distribution box, and the DC combiner box is connected with the main controller , and a centralized inverter is connected between the DC combiner box and the AC distribution box, a bidirectional inverter is connected between the AC distribution box and the battery, and the AC distribution box is connected to the power grid. The invention overcomes the defects of the photovoltaic grid-connected power generation system with battery and without battery, not only can be used for a period of time during public power outages, but also greatly reduces the occupation of equipment, high integration and good adjustment adaptability.

Description

A photovoltaic grid-connected power generation system

technical field

The invention relates to the technical field of photovoltaic power generation, in particular to a photovoltaic grid-connected power generation system.

Background technique

At present, energy and environmental issues have become the main problems faced by sustainable development. As an important renewable energy, solar energy reduces the consumption of coal and oil to a certain extent, and is a new energy that adapts to the development of the times and the needs of environmental protection. In recent years, the application of small-scale solar photovoltaic power generation systems has been rapidly developed, and it has a wider application prospect.

The photovoltaic grid-connected power generation system mainly includes two forms: with battery and without battery. The form without battery is to convert the direct current generated by the solar module into the alternating current that meets the requirements of the mains grid and then directly connect to the public. Although the cost of the power grid is low, photovoltaic power generation cannot operate when the public power is cut off, and there are certain defects in its use. On the one hand, the form with batteries not only increases the production cost, but also has fatal disadvantages such as large volume and land occupation, especially in the urban construction environment where there is a shortage of land, the photovoltaic modules will occupy a certain terrain, and the battery pack will also occupy another Indoor area. There are certain defects in the two types of photovoltaic grid-connected power generation systems. Therefore, it is necessary to design a photovoltaic grid-connected power generation system that integrates the two forms, which can not only solve the situation that the mains power fails to operate, but also reduce the overall occupation of the equipment. land area.

SUMMARY OF THE INVENTION

The purpose of the present invention is to overcome the problems raised in the background art and provide a photovoltaic grid-connected power generation system.

The object of the present invention is achieved through the following technical solutions: a photovoltaic grid-connected power generation system, including a current processing system and a plurality of integrated photoelectric conversion components, each integrated photoelectric conversion component includes a photovoltaic assembly integrated on a support, A main controller and a battery, a maximum power tracker is connected between the photovoltaic module and the main controller, a charge and discharge controller is connected between the battery and the main controller, and a cooling fan for the photovoltaic module is connected to the main controller, The current processing system includes a DC combiner box, an AC distribution box and an AC circuit breaker. The DC combiner box is connected to the current signal output end of the main controller and integrates the DC power generated by a plurality of photovoltaic modules into a DC unit, and the DC A centralized inverter is connected between the combiner box and the AC distribution box, which is used to convert the integrated DC unit into an AC unit, and a bidirectional inverter for converting current signals is connected between the AC distribution box and the battery. The AC power distribution box is connected to the power grid through the AC circuit breaker, the DC combiner box is connected with a DC load, and the AC power distribution box is connected with an AC load.

Further, the bracket includes a bottom plate, pillars vertically supported on both sides of the bottom plate, and a photovoltaic panel support frame hinged on the two side pillars. The side plates on both sides of the frame, the two ends of the main shaft respectively pass through the pillars on both sides and are fixedly connected with the side plates on the corresponding side. The photovoltaic panels connected to the main controller are placed on the frame, so A mounting shell is fixed on the base plate, the maximum power tracker, the main controller, the charge and discharge controller and the battery are all arranged in the mounting shell, the middle part of the main rotating shaft is located directly above the mounting shell, and the middle part of the main rotating shaft is located in the mounting shell. A plurality of vertically downward force-bearing plates are fixed, and at least a pair of limit posts are fixed on the upper surface of the installation shell. The rotation angle of the force plate, the upper surface of the installation shell is provided with a plurality of thermal driving devices for the front top force plate, and the bottom of the bottom plate is provided with a plurality of universal rollers.

Further, the thermal driving device includes a long strip with an open head end and a sealed outer casing and a sealed outer cylinder placed in the outer casing, a glass protection plate is provided at the sealing end of the outer casing, and the sealed outer cylinder is close to the outer casing. The surface of the end of the casing and the inner part of the glass protection plate is coated with a light-to-heat conversion coating, a piston is arranged in the sealed outer cylinder, and a gas that can be heated and expandable is injected between one side of the piston and the inner cavity of the sealed outer cylinder, and the other side of the piston. A piston rod for pushing the force plate is fixed on one side.

Further, a flat push plate is fixed at the end of the piston rod.

Further, the mounting shell is provided with a heat dissipation hole, and the heat dissipation fan is disposed in the heat dissipation hole and connected to the main controller.

Further, a transparent condensing lens is placed on the frame frame, and the condensing lens is located above the photovoltaic panel.

Further, the frame frame is provided with a stepped chute, the photovoltaic panel is placed in the chute of the lower step, the condenser lens is placed in the chute of the upper step, and the frame is inclined. The downward side is sealed and the slanted upward side is open.

Further, an adjustable rain shielding mechanism is provided on one side of the opening of the frame frame, and the rain shielding mechanism includes a rain shield and two adjustment bolts, and both sides of the rain shield are provided with strip holes, and the two The two adjusting bolts pass through the two strip holes respectively and fix the rain shield on the open side of the frame frame.

The beneficial effects that the present invention has are:

1. By integrating the photovoltaic modules, the main controller and the battery on one support, the available space of the traditional photovoltaic panel support is greatly utilized, which not only realizes the photovoltaic grid-connected power generation form with the battery, but also serves as a load when the public power is cut off. Power supply, and greatly reduce the area of equipment, alleviating the shortage of urban construction land;

2. By setting a rotatable photovoltaic panel support frame and a thermal drive device that can drive the photovoltaic panel support frame to rotate, when the solar radiation intensity is high or the radiant heat energy is concentrated, the thermal drive device is driven by heat and pushes the photovoltaic panel support frame to rotate, thereby Spontaneously adjust the angle of the photovoltaic panel in order to fully receive solar radiation energy, when the solar radiation intensity becomes lower, the angle of the photovoltaic panel support frame rotates normally;

3. By setting a condensing lens on the photovoltaic panel, the condensing lens can not only concentrate light, but also reduce the possibility of equipment failure caused by raindrops falling on the photovoltaic panel in rainy weather. The photovoltaic panels can be fully protected in rainy weather.

Description of drawings

Fig. 1 is the system connection schematic diagram of the present invention;

2 is a schematic structural diagram of an integrated photoelectric conversion component in the present invention;

FIG. 3 is an enlarged schematic diagram of part A of FIG. 2 .

Markings in the figure: 1-base plate; 2-pillar; 3-installation shell; 4-photovoltaic panel support frame; 5-main shaft; 6-force plate; 7-universal roller; 8-thermal drive device; 9-poly Optical lens; 10-photovoltaic panel; 11-weather plate; 12-strip hole; 13-adjusting bolt; 14-cooling fan; 15-limiting column; 41-frame frame; 42-side plate; 81-casing ; 82 - glass protection plate; 83 - sealed outer cylinder; 84 - piston rod; 85 - flat push plate.

Detailed ways

As shown in FIGS. 1 to 3 , the photovoltaic grid-connected power generation system provided in this embodiment includes a current processing system and a plurality of integrated photoelectric conversion components, each integrated photoelectric conversion component includes a photovoltaic module integrated on a support, a main A maximum power tracker is connected between the controller and the battery, the photovoltaic module and the main controller. The maximum power tracker adopts a Boost converter, and the existing search algorithm is mainly used to complete the maximum power point tracking in the whole system. The main controller adopts STC12C5408AD A charge and discharge controller is connected between the single-chip microcomputer, the battery and the main controller. When the DC power generated by the photovoltaic module is generated, the STC12C5408AD single-chip microcomputer generates the SPWM signal to realize the tracking function of the current frequency and phase, and the Boost converter calculates and judges the maximum power point. position to determine the next control signal. The generated DC power is stored in the battery. By setting the charge-discharge controller, it can not only control the stored power in the battery, but also prevent the battery from being overcharged or over-discharged. Safety of battery use. When the battery power is stored, the excess DC power generated is fed into the current processing system.

The current processing system includes a DC combiner box, an AC distribution box and an AC circuit breaker. The DC combiner box is connected to the current signal output end of the main controller and integrates the DC power generated by a plurality of photovoltaic modules into a DC unit, and the DC A centralized inverter is connected between the signal transmission end of the combiner box and the signal transmission end of the AC distribution box. The centralized inverter is used to convert the combined DC unit into an AC unit. The AC distribution box is connected to the battery. A bidirectional inverter that converts current signals is connected between them, and the bidirectional inverter is arranged in the AC distribution box. The AC distribution box is connected to the mains grid through the AC circuit breaker, which improves the safety performance of the AC distribution box. The output end of the DC combiner box is connected with a DC load, and the output end of the AC distribution box is connected with an AC load. Part of the DC units integrated in the DC combiner box can be used for DC loads such as motors and desk lamps, and the other part is combined into the AC distribution box after DC/AC conversion for the use of AC loads. The stored electricity continues to supply power for DC loads and AC loads. When continuous rainy weather occurs, the current in the mains grid can be controlled to be stored in the battery for backup. Of course, it is necessary to design an electricity meter to purchase the corresponding grid electricity for use. , this part is an existing mature technology, so it is not repeated here.

In order to improve the integration degree of the entire integrated photoelectric conversion component and reduce its footprint, the bracket includes a base plate 1 , pillars 2 vertically supported on both sides of the base plate 1 , and a photovoltaic panel support frame hinged on the pillars 2 on both sides 4. A plurality of universal rollers 7 are arranged at the bottom of the bottom plate 1 to improve the convenience of movement of the device. The photovoltaic panel support frame 4 includes a main rotating shaft 5, a frame frame 42 inclined at 40°, and an integrally formed in the frame frame. The side plates 41 on both sides of the frame 42, the two ends of the main shaft 5 pass through the pillars 2 on both sides respectively through bearings and are fixedly connected with the side plates 41 on the corresponding side, so that the entire photovoltaic panel support frame 4 can rotate relative to the pillars 2. . A photovoltaic panel 10 connected to the main controller is placed on the frame 42 , and the photovoltaic panel 10 is the main component of the photovoltaic assembly. In order to prevent rainwater from immersing into the circuit structure inside the photovoltaic panel 10 in continuous rainy weather, a transparent condenser lens 9 is also placed on the frame frame 42. Specifically, the frame frame 42 is provided with a stepped type The photovoltaic panel 10 is placed in the chute of the lower step, and the condensing lens 9 is placed in the chute of the upper step, so that the condensing lens 9 is located above the photovoltaic panel 10, which can not only concentrate The effect of light can also prevent rainwater from soaking the photovoltaic panel 10 . In order to facilitate the installation of the photovoltaic panel 10 and the condensing lens 9 , the side of the frame frame 42 which is inclined downward is sealed, and the side which is inclined upward is opened. Slide into the corresponding chute. Due to the opening on the upper side of the frame frame 42, its airtightness is reduced, and an adjustable rain shielding mechanism is provided on one side of the opening of the frame frame 42. Both sides of the weather shield 11 are provided with strip holes 12, and the two adjusting bolts 13 respectively pass through the two strip holes 12 and fix the weather shield 11 on the opening side of the frame frame 42, and slide the shield upward. The rain shield 11 is sealed to the open side of the frame frame 42, and then the adjusting bolt 13 is tightened to fix the rain shield 11.

In order to prevent components such as batteries and main controllers from being directly exposed to sunlight, a mounting shell 3 is fixed on the bottom plate 1, and the mounting shell 3 is located directly below the photovoltaic panel support frame 4. The maximum power tracker, the main controller , The charge-discharge controller and the battery are integrated in the installation shell 3, the side wall of the installation shell 3 is provided with a plurality of heat dissipation holes, and at least one of the heat dissipation holes is provided with a heat dissipation fan 14 connected to the main controller, It is used to dissipate the heat in the cavity of the mounting shell 3. In this embodiment, the middle part of the main rotating shaft 5 is located directly above the installation shell 3 , and three vertical downward force plates 6 are fixed in the middle part of the main rotating shaft 5 , and the upper surface of the installation shell 3 is fixed There are a pair of limit posts 15, which are located on the front side and the rear side of the intermediate force plate 6 respectively and are used to limit the rotation angle of the force plate 6, and limit the inclination angle range of the entire photovoltaic panel support frame 4 to within the range of 30 to 40°. The photovoltaic panel support frame 4 is arranged in an east-west direction. At noon in direct sunlight, the radiant energy intensity is the highest. Adjusting the inclination angle of the photovoltaic panel 10 to 30° is convenient for receiving solar light more fully. In this embodiment, the photothermal driving mechanism is used to realize the rotation of the photovoltaic panel support frame 4, which greatly reduces the energy consumption. The driving device 8 and the thermal driving device 8 include a long-striped shell 81 with an open head and a sealed end and a sealed outer cylinder 83 placed in the shell 81. A glass protective plate 82 is provided at the sealing end of the shell 81, so The sealing outer cylinder 83 is made of aluminum-copper alloy, and the surface of the outer casing 81 close to the end of the outer casing 81 and located in the inner part of the glass protection plate 82 is coated with a light-to-heat conversion coating. The sealing outer cylinder 83 is provided with a piston (not shown), and the piston is A heat-expandable gas or liquid, preferably air, is filled between one side and the inner cavity of the sealed outer cylinder 83, which is low-cost and easy to obtain, and the other side of the piston is fixed with a piston rod 84 for pushing the force-bearing plate 6, The end of the piston rod 84 is fixed with a flat push plate 85 that increases the force-bearing area. When the noon light is strong, the conversion efficiency of the photothermal coating is improved, and the heat is conducted through the sealed outer cylinder 83, so that the air inside the seal continues to expand, thereby promoting The piston makes the piston rod 84 slowly push the force-bearing plate 6 forward to achieve the purpose of adjusting the angle of the photovoltaic panel support frame 4 without setting an additional power mechanism. Therefore, it can more fully receive solar light, completely change with the change of light intensity, and has high adaptability.

The invention overcomes the defects of the photovoltaic grid-connected power generation system with battery and without battery, not only can be used for a period of time during public power outages, but also greatly reduces the occupation of equipment, high integration and good adjustment adaptability.

The above are only the preferred embodiments of the present invention, but the protection scope of the present invention is not limited to this. Any modification and replacement based on the technical solutions and inventive concepts provided by the present invention should be covered by the protection scope of the present invention. Inside.

Claims (8)

1. A grid-connected photovoltaic power generation system is characterized in that: the photovoltaic conversion system comprises a direct current combiner box, an alternating current distribution box and an alternating current circuit breaker, wherein the direct current combiner box is connected with the current signal output end of the main controller and used for combining direct currents generated by a plurality of photovoltaic components into a direct current unit, a centralized inverter is connected between the direct current combiner box and the alternating current distribution box and used for converting the combined direct current unit into an alternating current unit, and a bidirectional inverter for converting current signals is connected between the alternating current distribution box and the storage battery, the alternating current distribution box is connected to a power grid through an alternating current breaker, a direct current load is connected to the direct current combiner box, and an alternating current load is connected to the alternating current distribution box.

2. The grid-connected photovoltaic power generation system according to claim 1, characterized in that: the support comprises a bottom plate, pillars vertically supported on two sides of the bottom plate and photovoltaic panel support frames hinged on the pillars on two sides, each photovoltaic panel support frame comprises a main rotating shaft, a frame-shaped frame obliquely arranged and side panels integrally formed on two sides of the frame-shaped frame, two end parts of the main rotating shaft respectively penetrate through the pillars on two sides and are fixedly connected with the side panels on the corresponding sides, the photovoltaic panel connected with a main controller is placed on the frame-shaped frame, an installation shell is fixed on the bottom plate, the maximum power tracker, the main controller, the charge and discharge controller and the storage battery are all arranged in the installation shell, the middle part of the main rotating shaft is positioned right above the installation shell, a plurality of vertically downward stress plates are fixed at the middle part of the main rotating shaft, at least one pair of limiting columns is fixed on the upper surface of the installation shell, and the pair of limiting columns are respectively positioned on the front side and the rear side of one stress plate and are used for limiting the, the mounting shell upper surface is provided with a plurality of thermal drive devices that are used for preceding top atress board, the bottom plate bottom is provided with a plurality of universal gyro wheels.

3. The grid-connected photovoltaic power generation system according to claim 2, characterized in that: the thermal driving device comprises a long strip-shaped opening and a head end opening, a tail end sealed shell and a sealed outer barrel arranged in the shell, wherein a glass protection plate is arranged at the tail end sealing position of the shell, the sealed outer barrel is close to the tail end of the shell and is positioned in the glass protection plate, a photo-thermal conversion coating is coated on the surface of the inner part of the glass protection plate, a piston is arranged in the sealed outer barrel, gas capable of expanding by heating is injected between one side of the piston and the inner cavity of the sealed outer barrel, and a piston rod used for pushing a stress plate.

4. The grid-connected photovoltaic power generation system according to claim 3, characterized in that: and a flat push plate is fixed at the end part of the piston rod.

5. The grid-connected photovoltaic power generation system according to claim 4, characterized in that: the mounting shell is provided with heat dissipation holes, and the heat dissipation fan is arranged in the heat dissipation holes and connected with the main controller.

6. The grid-connected photovoltaic power generation system according to claim 2 or 3, characterized in that: and a transparent condensing lens is also arranged on the frame, and the condensing lens is positioned above the photovoltaic panel.

7. The grid-connected photovoltaic power generation system according to claim 6, characterized in that: be provided with the spout of notch cuttype on the frame, the photovoltaic board is placed in the spout of lower floor's ladder, condensing lens places in the spout of upper ladder, frame slope one side down is sealed, the ascending side opening of slope.

8. The grid-connected photovoltaic power generation system according to claim 7, characterized in that: the adjustable rain-shielding mechanism is arranged on one side of the opening of the frame, the rain-shielding mechanism comprises a rain-shielding plate and two adjusting bolts, strip-shaped holes are formed in two sides of the rain-shielding plate, and the two adjusting bolts penetrate through the two strip-shaped holes respectively and fix the rain-shielding plate on one side of the opening of the frame.