KR101280262B1

KR101280262B1 - Efficiency enhancement equipment for solar photovoltaic power facilities

Info

Publication number: KR101280262B1
Application number: KR1020110115585A
Authority: KR
Inventors: 유상필
Original assignee: (주)하이레벤
Priority date: 2011-11-08
Filing date: 2011-11-08
Publication date: 2013-07-08
Also published as: KR20130050494A

Abstract

The present invention relates to a facility for improving efficiency of photovoltaic power generation facilities. The efficiency improving equipment of the solar power plant according to the present invention is to maintain or improve the efficiency by spraying the coolant to the solar power plant comprising a photovoltaic array that collects sunlight to generate electricity, cooling water Storage tank for storing the; Coolant injection means for injecting coolant into the photovoltaic array; And a pump for pumping the coolant stored in the storage tank and supplying the cooling water to the cooling water injection means through a cooling water supply pipe, wherein the photovoltaic arrays are divided into regions by inverters connected to each other, and the cooling water supply pipe is branched by the region. It includes a branch pipe for supplying the cooling water to the cooling water injection means, characterized in that the valve for opening and closing the branch pipe to control the cooling water injection of the cooling water injection means is arranged for each branch pipe.
According to the above-described efficiency improving apparatus of the solar power generation facility, by disposing the cooling water supply pipe for each photovoltaic array divided by the inverter connection, it is possible to optimize and optimize the cooling water injection control for each electric region. In addition, it is possible to effectively reduce the temperature difference between the photovoltaic array in the photovoltaic array divided by the same inverter connection, thereby minimizing the output power loss due to unbalanced power generation between the photovoltaic array.

Description

[0001] EFFICIENCY ENHANCEMENT EQUIPMENT FOR SOLAR PHOTOVOLTAIC POWER FACILITIES [0002]

The present invention relates to a facility for improving efficiency of photovoltaic power generation equipment, and more particularly, to photovoltaic power generation that can minimize output power loss due to unbalanced power generation between photovoltaic arrays in the same inverter area divided by inverter connection. The present invention relates to equipment for improving efficiency of equipment.

The method of generating power using solar energy is largely divided into a method using solar heat and a method using solar light. In general, a power generation method that converts sunlight directly into electric energy is called solar power generation.

Photovoltaic power generation uses the principle that electron-hole electromotive force is generated by light energy when solar light is irradiated on pn junction photovoltaic panel with n-type doping on silicon crystal. is called an effect).

More specifically, the photovoltaic effect is that when light is incident on the photovoltaic module from the outside, electrons in the conduction band of the p-type semiconductor are excited to a valence band by the incident light energy. The excited electrons form one electron hole pair (EHP) inside the p-type semiconductor, and the electrons of the generated electron-hole pairs are formed between the pn junctions. field to the n-type semiconductor to supply current to the outside.

The smallest unit that generates electricity in a solar power generation facility is a solar cell, and these cells are gathered together to form a solar module, and the solar modules are gathered together to form a solar array. Typically, several such arrays are connected to one inverter.

Unlike existing energy sources such as fossil raw materials, sunlight is a clean energy source that does not have the danger of global warming, such as greenhouse gas emissions, noise, environmental destruction, etc., and there is no fear of depletion. Unlike other types of wind and seawater, solar power generation facilities are free from installation and maintenance costs.

However, in the case of the most widely used silicon solar cell, when the temperature of the photovoltaic module rises, output decrease of 0.5% per 1 ° C occurs. According to these characteristics, the output of solar power peaks in spring and autumn, not in the summer when the sun is the longest. This increase in temperature is a major cause of lowering the power generation efficiency of photovoltaic power generation.

In addition, dirt or snow such as yellow dust, dust, and bird droppings may easily accumulate in the solar module, and these may drastically reduce the light transmittance of the solar module, thereby reducing power generation efficiency.

Therefore, in order to maintain the efficiency of the solar power generation, it is necessary to prevent the increase of the temperature of the solar module and to prevent the decrease of the light transmittance due to dirt and snow, and the efficiency improvement facility (maintenance facility) of the solar power generation facility is used for this purpose.

As shown in FIG. 1, the efficiency improvement equipment of the photovoltaic power generation facility lowers the temperature of the photovoltaic array by spraying the coolant to the photovoltaic array 7 through a coolant injection means 6 such as a nozzle. It cleans and removes dirt, snow, and rain accumulated in the photovoltaic array to maintain the photovoltaic power generation facilities so that the photovoltaic array can generate a constant output.

In relation to such an efficiency-enhancing facility, since the photovoltaic power generation facilities are installed on a large scale, it is impossible to equip all the facilities to simultaneously spray cooling water to all the photovoltaic arrays. Therefore, the cooling water is sequentially sprayed for each predetermined region, and accordingly, a difference occurs in the power generation of the photovoltaic array between the respective regions, and an imbalance of the power generation between the photovoltaic arrays causes a loss of output power during power conversion. Let's go.

In order to solve this problem, the present invention efficiently and optimizes cooling water injection control for a photovoltaic array by separately arranging cooling water supply pipes for each photovoltaic array connected to the same inverter. It is an object of the present invention to provide a facility for improving efficiency of photovoltaic power generation facilities that can minimize output power loss due to unbalanced power generation between arrays.

In order to achieve the above object, the present invention, the efficiency of the photovoltaic power generation facilities to maintain or improve the efficiency by spraying the coolant to the photovoltaic power generation facilities comprising a photovoltaic array for generating electricity by condensing sunlight An improvement apparatus, comprising: a storage tank for storing cooling water; Coolant injection means for injecting coolant into the photovoltaic array; And a pump for pumping the coolant stored in the storage tank and supplying the cooling water to the cooling water injection means through a cooling water supply pipe, wherein the photovoltaic arrays are divided into regions by inverters connected to each other, and the cooling water supply pipe is branched by the region. It includes a branch pipe for supplying the cooling water to the cooling water injection means, the valve for controlling the cooling water injection of the cooling water injection means by opening and closing the branch pipe is disposed for each branch pipe to improve the efficiency of the photovoltaic power generation equipment Provide facilities.

The efficiency improvement apparatus may further include a control unit controlling the driving of the pump and the opening and closing of the valve to control the cooling water injection of the cooling water injection means.

Valves arranged for each branch pipe may be opened and closed sequentially, for example.

The photovoltaic arrays for each region are divided into two or more sub-regions, and the branch pipe includes a sub-branch pipe branched for each of the sub-regions, and controls the cooling water injection of the coolant injection means by opening and closing the sub-branch pipe. Sub-valve may be arranged for each sub branch pipe.

The sub valves can be opened and closed at the same time.

In addition, the sub-valve may be opened and closed sequentially. In this case, the sub-valve may be opened and closed sequentially from the photovoltaic array having a high temperature in each sub-region.

The controller may end the driving of the pump when the pressure in the cooling water supply pipe exceeds a set maximum value or falls below a set minimum value.

Preferably, the cooling water spraying means injects a collision jet of cooling water to the photovoltaic array.

The control unit may cause the cooling water spraying unit to spray cooling water for a set driving time.

The control unit may cause the coolant spray means to spray coolant according to the temperature of the photovoltaic array.

The control unit may cause the coolant spraying means to spray coolant according to the coolant storage amount of the storage tank.

According to the above-described efficiency improving equipment of the photovoltaic power generation equipment, the cooling water injection control for the photovoltaic array divided by each inverter connection by separating and arranging the cooling water supply pipes for each photovoltaic array divided by the inverter connection. Can be optimized and efficient.

By using the efficiency improving apparatus of the present invention, it is possible to effectively reduce the temperature difference between the photovoltaic array divided by the same inverter connection, thereby minimizing the output power loss due to unbalanced power generation between the photovoltaic array. .

1 is a view showing an efficiency improvement method of the photovoltaic power generation equipment using the cooling water injection.
2 is a view schematically showing the configuration of the efficiency improving equipment of the photovoltaic power generation equipment according to an embodiment of the present invention.
3 is a conceptual diagram illustrating output power loss according to a difference in power generation between photovoltaic arrays.
4 is a view schematically showing the configuration of the efficiency improving equipment of the photovoltaic power generation equipment according to another embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms or words used herein are not to be construed as being limited to conventional or dictionary meanings, but should be construed as meanings and concepts corresponding to the technical matters of the present invention.

The embodiments described in the present specification and the configurations shown in the drawings are preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention and thus various equivalents and modifications Can be.

Figure 2 is a block diagram showing the efficiency improvement equipment of the photovoltaic power generation equipment according to an embodiment of the present invention.

1 and 2, photovoltaic arrays 7 for concentrating solar power and generating electricity are listed. As an equipment for maintaining and managing photovoltaic arrays 7, an efficiency improving apparatus is provided. It is installed.

The photovoltaic array 7 is a collection of a plurality of solar cells. When light is incident on the photovoltaic array 7 from the outside, electricity is generated by the photovoltaic effect.

However, since the photovoltaic array 7 is installed externally to condense solar light, it is exposed to the external environment as it is, and contaminants such as scattering dust, algae secretions, and yellow sand adhere to it, thereby reducing the amount of condensed light. Will decrease. In addition, by being continuously exposed to sunlight and heated by solar heat, the internal resistance of the photovoltaic array is increased, which is also a factor for lowering the power generation efficiency.

The present invention relates to a facility that can maintain and improve the efficiency of photovoltaic power generation by cooling and washing the photovoltaic array (7) using cooling water, and the efficiency of the photovoltaic power generation system according to an embodiment of the present invention. The upgrade facility includes a storage tank 1, a coolant spray means 6, a coolant supply pipe 5, a pump 25, valves 21 to 24, a control unit 3 and a sensing unit 4.

Cooling water injection means (6) is installed to correspond to each of the photovoltaic array (7) is a means for injecting the coolant to spray the coolant to the photovoltaic array (7). In this embodiment, the coolant injection means 6 is arranged to correspond to each photovoltaic array 7, but if necessary, one coolant injection means 6 is used to cool the photovoltaic array 7 to several solar power arrays 7. May be sprayed or several coolant spray means 6 may spray coolant to one photovoltaic array 7.

On the other hand, in injecting the cooling water from the cooling water injection means 6 to the photovoltaic array 7, it is difficult to obtain sufficient cooling and cleaning effects by flowing the cooling water to the photovoltaic array 7 or spraying it weakly. It is preferable to spray the collision jet of cooling water to the photovoltaic array 7.

The impingement jet has excellent heat and fluid transfer effects from the fluid to the impingement surface, thereby improving the cooling and cleaning effect and reducing the generation of scale. However, in order to generate a collision jet, the speed of the coolant is 30 m / s or more and the pressure is 1.6 kg / cm ² or more, based on the inlet of the coolant spray means 6 for injecting the coolant into the photovoltaic array 7. It is preferable. Here, the inlet of the coolant spray means 6 refers to the end of the coolant spray means 6 into which coolant is injected to the outside.

The cooling water injection means 6 is preferably fixed so that the cooling water is evenly sprayed on the front surface of the photovoltaic array 7 while reciprocating left and right without spraying the cooling water only in one direction.

If the cooling water injection means 6 is fixed and sprays the cooling water to the front of the photovoltaic array 7, the amount of water that can be supplied by the pump per hour is limited, so that the water jet pressure is reduced and a collision jet is applied to the front of the photovoltaic array. It is not easy to generate. However, when the coolant spray means 6 sprays coolant only on a part of the photovoltaic array 7 while the coolant spray means 6 reciprocates from side to side, it is possible to easily generate a collision jet by increasing the water pressure of the coolant. Through the cooling and cleaning efficiency can be improved.

The cooling water supply pipe 5 serves to deliver the cooling water supplied from the storage tank 1 to the injection means 6 through the pump 25, and is preferably buried in the ground to maintain the temperature of the cooling water.

The pump 25 pumps the cooling water stored in the storage tank 1 and supplies the cooling water to the cooling water injection means 6 through the cooling water supply pipe 5.

Cooling water supply pipe 5 is disposed separately for each electric region divided by the inverter (101 ~ 104). That is, the photovoltaic arrays 7 are divided into regions for each of the inverters 101 to 104 connected to each other, and the cooling water supply pipe 5 includes branching pipes 51 to 54 branched into the regions.

The valves 21 to 24 open and close the branch pipes 51 to 54 to control the cooling water injection through the cooling water injection means 6.

Thus, by arranging the branch pipes (51 to 54) for each electric region divided by the inverter (101 to 104) and the valves (21 to 24) for each branch pipe (51 to 54), for the entire electric region Coolant injection control can be optimized and streamlined. Since the coolant is sprayed and stopped at the same time in the same electric region by opening and closing the valves 21 to 24, the temperature difference according to the difference in the amount of coolant sprayed between the photovoltaic arrays 7 can be reduced in the same electric region. Accordingly, the output power loss due to the difference in power generation between the photovoltaic array 7 can be minimized.

The power generated in the photovoltaic array 7 is output through the inverters 101 to 104. When there is an imbalance in the generated power between the photovoltaic arrays 7, the output deviation between arrays in the same inverter region connected in series is There is a loss in output power due to the hot spot effect being harvested below the sum of the outputs.

In (a) and (b) of FIG. 3, the long box on the left side shows the generated power of the photovoltaic array divided by six inverters as a relative value. Here, the sum of the total generated power of each array is 40 for (a) and 32 for (b), where (a) is higher than (b). However, when the inverters are not operated independently but integrated and run in parallel and optimized in the operation mode, the generated power represents 24 (4x6) in the case of (a) and 30 (5x6) in the case of (B). . In the case of (a), a large output power is lost due to the imbalance of the power generation between the photovoltaic arrays, and thus, the output power is lower than that in the case of (b).

Each valve 21 to 24 is opened or closed simultaneously or in a set order. Sufficient injection pressure can be obtained with a small number of pumps 25 or a small capacity pump 25 by opening and closing the valves 21 to 24 in a set order.

The control part 3 is a part which controls the drive part 9 including the pump 25 and the valves 21-24, drives or stops the pump 25, and opens or closes the valves 21-24.

The way in which the control unit 3 controls the pump 25 and the valves 21 to 24 is not particularly limited, but is preferably designed to maximize the use efficiency of the cooling water. A control method capable of improving the use efficiency of the cooling water will be described as an example.

As a first example, this is a time-based control scheme. Specifically, the control unit 3 determines whether the drive start time, and if the drive start time drive the pump 25, and opens and closes each valve 21 to 24 sequentially for a set time. It is possible to set the start time and opening time of the valves 21 to 24 in consideration of the region of the solar power generation facility and the characteristics of the facility.

Another example is the temperature control method. Specifically, it is determined whether the measured temperature difference between the temperature of the photovoltaic array 7 and the cooling water is equal to or greater than the set temperature difference between the temperature of the photovoltaic array 7 and the cooling water, and the If the measured temperature difference between the temperature and the coolant is greater than or equal to the temperature difference between the temperature of the photovoltaic array 7 and the set value of the coolant, the pump 25 is driven and the respective valves 21 to 24 are sequentially operated. Open and close; The temperature difference setting value of the temperature of the photovoltaic array 7 and the cooling water may be set in consideration of the region where the photovoltaic facility is installed and the characteristics of the facility.

In addition, in consideration of the amount of cooling water stored in the storage tank 1 and the supply speed of the cooling water supplied to the storage tank 1, it is preferable to control the injection amount of the cooling water so that the cooling water is properly distributed during the driving time. In this case, the injection amount of the cooling water may be controlled to be sprayed at the same speed every hour, or may be controlled to be sprayed at different time intervals.

On the other hand, the controller 3 terminates the driving of the pump 25 when water leaks in the cooling water supply pipe 5, a passage is blocked or narrowed by dirt, or an abnormal state such as freezing of the cooling water occurs. . In this abnormal state, the smooth supply of the cooling water is impossible, and in the case of the abnormal state, the wastewater of the huge cooling water and the failure of the equipment are caused. Therefore, when the controller 3 determines that the abnormal state is abnormal, the driving of the pump 25 is terminated. Solve the above problem.

The control unit 3 uses the pressure in the cooling water supply pipe 5 to determine whether it is in an abnormal state. When the pressure in the cooling water supply pipe 5 exceeds the maximum value of the set pressure range, the control unit 3 may freeze or dirty the cooling water. When the cooling water supply pipe 5 is recognized as being narrowed or clogged, the driving of the pump 25 is terminated, and when the pressure in the cooling water supply pipe 5 is lower than the set minimum value, the cooling water supply pipe 5 is recognized as having a leak. To end the drive.

The pressure sensor 41 may be used to measure the pressure in the coolant supply pipe 5, and the pressure sensor 41 may be used without particular limitation as long as it can measure the water pressure in the coolant supply pipe 5.

In addition, the pressure sensor 41 may be disposed in the branch pipes 51 to 54 or may be disposed between the branch point D of the pump 25 and the cooling water supply pipe 5.

The controller 5 preferably determines the abnormal state to terminate the driving of the pump 25 only when the time in which the pressure in the cooling water supply pipe 5 exceeds the maximum value or falls below the minimum value is maintained for a predetermined time or more. In the pressure measurement in the coolant supply pipe 5, noise may be measured in the pressure sensor 5, and temporarily out of the set pressure range, such as instantaneous high pressure and low pressure occurring in the coolant supply pipe 5, may be an actual abnormal state. Since it may not be, the operation of the pump 25 is terminated only when the set pressure range is out of a predetermined time or more, so that the abnormal state can be more accurately determined and effective facility operation is possible.

The time out of the set pressure range, which is a criterion for determining the abnormal state, may be appropriately set in consideration of various factors such as the capacity of the pump 25, the number of the coolant injection means 6, the diameter of the coolant supply pipe 5, and the like. In addition, the criteria for the time exceeding the highest value and the time lower than the lowest value may be set the same as each other or individually.

In the measurement of whether the pressure in the cooling water supply pipe 5 is below the minimum value of the setting range, the pressure in the cooling water supply pipe 5 is measured to be low before the cooling water supply pipe 5 is filled with the cooling water supply pipe 5 for each sector. 5) It is preferable to determine the abnormal state when the pressure measured after the cooling water is filled in the entire body reaches the minimum value for a predetermined time or more.

To this end, the control unit 3 is the pump 25 when the pressure in the coolant supply pipe 5 has not continuously exceeded the set minimum value for a predetermined time after the set time has elapsed since the valves 21 to 24 are opened. ) Can be terminated.

Furthermore, the controller 3 may terminate the driving of the pump 25 when the pressure in the cooling water supply pipe 5 continuously exceeds the set minimum value for a predetermined time or more until the valves 21 to 24 are closed. .

In order to control the pump 25 and the valves 21 to 24 as described above, the control unit 3 receives various sensing information from the sensing unit 4, and the pressure unit 41 and the timer 42 are provided at the sensing unit. , The water level sensor 43, the temperature sensor 44 may be provided.

4 is a view schematically showing the configuration of the efficiency improving equipment of the photovoltaic power generation equipment according to another embodiment of the present invention.

In the present embodiment, each electric region 71 to 73 is divided into two or more sub areas 711 to 714, 721 to 724, and 731 to 734. On the other hand, the sub branch pipes 511 to 514, 521 to 524, and 531 to 534 are disposed in the sub areas 711 to 714, 721 to 724, and 731 to 734, and the sub branch pipes 511 to 514 and 521 to 524. And sub valves 211 to 214, 221 to 224, and 231 to 234 for each of 531 to 534.

By adopting such a configuration, when the inverter capacity is large and the number of photovoltaic arrays 7 is large in one electric region, the pump 75 and piping equipment can be made efficient, and the injection pressure of the cooling water can be improved. If necessary, the subregions 711 to 714, 721 to 724, and 731 to 734 are divided into sub-areas, and the branch pipes and sub valves 211 to 214 under the sub branch pipes 511 to 514, 521 to 524, and 531 to 534. , 221 to 224 and 231 to 234 may be disposed below the valve.

The sub valves 211 to 214, 221 to 224, and 231 to 234 within the same electric region may be opened or closed simultaneously or sequentially. In the case of simultaneous opening and closing, the cooling water is injected and stopped at the same time in the photovoltaic array 7 in the same electric region, thereby eliminating the temperature variation, but it may not be possible to obtain sufficient cooling water injection pressure at the predetermined number and capacity of the pumps 25. have. Accordingly, the cooling water may be injected at a sufficient injection pressure by opening and closing the sub valves 211 to 214, 221 to 224, and 231 to 234 sequentially in a predetermined order.

The opening / closing order of the sub valves 211 to 214, 221 to 224, and 231 to 234 may, for example, cause each sub valve 211 to 214, 221 to 224, and 231 to 234 to be opened and closed at a predetermined time interval. . In addition, according to the temperature of each sub-region, that is, each sub-valve (211 ~ 214, 221 ~ 224, 231 ~ 234) so that the cooling water is injected for a predetermined time from the photovoltaic array (7) having a high temperature in the sub zone Can be opened and closed. However, this is exemplary and the opening and closing order of the sub valves 211 to 214, 221 to 224, and 231 to 234 may be determined in various ways.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the following claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

Claims

In the efficiency improvement equipment of the photovoltaic power generation equipment to maintain or improve the efficiency by spraying the coolant to the photovoltaic power generation equipment comprising a photovoltaic array for collecting electricity to generate electricity,
A storage tank for storing coolant;
Coolant injection means for injecting coolant into the photovoltaic array;
A pump for pumping the coolant stored in the storage tank to supply the coolant injection means through a coolant supply pipe;
The photovoltaic arrays are divided into regions for each inverter connected to each other, and the cooling water supply pipe includes a branch pipe branched by the region to supply the cooling water to the cooling water injection means.
A valve for controlling the cooling water injection of the cooling water injection means by opening and closing the branch pipe is disposed for each of the branch pipe efficiency improving equipment.

The method of claim 1,
Further comprising a control unit for controlling the driving of the pump and the opening and closing of the valve to control the cooling water injection of the cooling water injection means.

The method of claim 2,
The valves arranged for each branch pipe are improved efficiency of the solar power plant, characterized in that the opening and closing sequentially.

The method of claim 2,
The photovoltaic arrays for each region are divided into two or more sub-regions, and the branch pipe includes a sub-branch pipe branched into the sub-regions.
A sub-valve for controlling the cooling water injection of the cooling water injection means by opening and closing the sub-branch pipe is disposed for each of the sub-branch pipes, the efficiency improvement equipment of the solar power plant.

5. The method of claim 4,
The sub-valve is improved efficiency of the solar power plant, characterized in that the opening and closing at the same time.

5. The method of claim 4,
The sub-valve is improved efficiency of the solar power plant, characterized in that the opening and closing sequentially.

The method according to claim 6,
Said sub-valve is sequentially opened and closed from the photovoltaic array having a high temperature in each sub-region.

The method of claim 2,
The control unit is an efficiency improving equipment of the solar power plant, characterized in that to terminate the drive of the pump when the pressure in the cooling water supply pipe exceeds the set maximum value or less than the set minimum value.

The method of claim 1,
The cooling water spraying means is an efficiency improving equipment of the solar power plant, characterized in that for spraying the jet of cooling water to the photovoltaic array.

The method of claim 2,
The control unit, the efficiency improving equipment of the solar power plant, characterized in that the cooling water spraying means to spray the cooling water for a set driving time.

The method of claim 2,
The controller determines whether a temperature difference measurement value between the temperature of the photovoltaic array and the cooling water is equal to or greater than a temperature difference setting value between the temperature of the photovoltaic array and the cooling water, and when the measured value is greater than or equal to the set value. Efficiency improvement equipment of the solar power plant, characterized in that for spraying the cooling water through the cooling water injection means until it is less than that.

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