WO2020250243A1

WO2020250243A1 - A system and method for reducing power loss in electric cables of photovoltaic modules

Info

Publication number: WO2020250243A1
Application number: PCT/IN2020/050514
Authority: WO
Inventors: Seshadri DEVANADHAN
Original assignee: Tata Power Solar Systems Ltd
Priority date: 2019-06-11
Filing date: 2020-06-10
Publication date: 2020-12-17

Abstract

The invention provides a system and method for reducing power loss in a photovoltaic power station. Photovoltaic modules (102) with same or nearby length electric cables (104) are grouped (106) together. Clusters (110) of similar length electric cables (104) are formed using clustering modules (108). The clustered (110) electric cables (104) are connected to compartments (114) of an inverter (112). Similarly, the compartments (114) of each inverter (112) present in the photovoltaic power station receives clustered (110) similar length electric cables (104) from groups (106) of photovoltaic modules (102) comprising same or nearby length electric cables (104). Power loss in the electric cables (104) of the photovoltaic modules (102) is reduced by this way, thereby reducing overall power loss in the photovoltaic power station.

Description

A system and method for reducing power loss in electric cables of photovoltaic modules

The present invention generally relates to a system and method for reducing power loss in electric cables of photovoltaic modules. More specifically, the invention relates to the field of clustering similar length electric cables and connecting the clustered electric cables to compartments of an inverter in a photovoltaic power station.

With an increasing need for fuel, and electricity, the focus of technology has seen a shift from non-renewable sources of energy to renewable sources such as solar energy, thus marking a significant spike in research revolving around the harnessing of energy from the sun.

Solar energy has the potential to meet many challenges facing the world, and has multiple reasons to promote its share in the energy market. Owing to the multi-faceted benefits of solar energy to people and the environment, solar energy is an emerging popular choice.

Photovoltaic panels are one of the most widely used solar devices in households as well as the industrial domain. Electrical appliances in homes and industries, and heavy machinery in large industries are connected to the solar panels to receive electricity for their functioning.

Traditionally, solar panels are connected to various devices via bus bars and inverters. Further, depending on the placement of the solar panels from the devices, electrical cables of varying lengths are used to connect the solar panels to the devices, via the bus bars. Wherever multiple electric cables are connected to a single bus bar, a significant amount of power loss is incurred. The lengths of the electric cables connecting the devices and the bus bar are prone to losses, and the amount of losses is proportional to the length of the electric cables. It is known in the art that the length of the electric cables used for power transmission affects the strength of transmitted power.

The existing methods of optimal power transmission through electric cables are not very effective when it comes to reducing power losses in the cables. Consequently, it results in an undesirable redundancy in the utilization of solar power.

The traditional methods of power transmission also focus more on utilizing different methods of reducing power losses or voltage drop, than optimizing cables and cable lengths.

Thus, in the light of the foregoing discussion, it is the need of the hour to have a system and method that effectively utilizes cable lengths in solar panels to reduce or minimize the power losses incurred in the electric cables.

Object of Invention

The principal object of the invention is to provide a system and method for reducing power loss in a photovoltaic power station.

It is another object of the invention to provide a method for reducing power loss in electric cables of photovoltaic modules.

It is yet another object of the invention to provide inverters with three or more compartments.

It is still another object of the invention to provide a method of grouping photovoltaic modules with same or similar length electric cables.

It is a further object of the invention to provide a method of clustering similar length electric cables.

It is another object of the invention to provide a method for reducing power loss in the electric cables by connecting the clustered electric cables of similar lengths into a compartment of the inverter.

The present invention discloses a system and method for reducing power loss in a photovoltaic power station. Electric cables from each photovoltaic module present in the photovoltaic power station are of different lengths, depending on the distance and connection between the photovoltaic module and inverter. The photovoltaic modules with electric cables having same or similar lengths are grouped. Subsequently, clustering of the same/similar length electric cables is carried out and the clustered cables are connected to the inverter. The inverter comprises three or more compartments for receiving the clustered cables. Each compartment of the inverter receives a cluster of similar length electric cables from groups of photovoltaic modules. Similarly, each inverter present in the photovoltaic power station receives the clustered electric cables from groups of photovoltaic modules with same or similar length electric cables. Power loss in the electric cables of each photovoltaic module is reduced by connecting the electric cables of same/similar length into compartments of the inverters, thereby reducing overall power loss in the photovoltaic power station.

This invention is illustrated in the accompanying drawings, throughout which, like reference letters indicate corresponding parts in the various figures.

The embodiments herein will be better understood from the following description with reference to the drawings, in which:

Fig.1

depicts a network of devices, in accordance with various embodiments of the invention.

Fig.2

depicts a system illustrating connection between groups of photovoltaic modules, electric cables and inverter compartments for reducing power loss in a photovoltaic power station.

Fig.3

depicts a flowchart illustrating a method of reducing power loss in a photovoltaic power station.

Fig.4a

depicts/illustrates a graph comparing voltage drop in conventional and proposed systems, in accordance with an exemplary embodiment of the invention.

Fig.4b

depicts/illustrates a bar chart comparing the average voltage drop in conventional and proposed systems, in accordance with an exemplary embodiment of the invention.

Fig.5a

depicts/illustrates a graph comparing the percentage (%) voltage drop in conventional and proposed systems, in accordance with an exemplary embodiment of the invention.

Fig.5b

depicts/illustrates a bar chart comparing the average percentage (%) voltage drop between conventional and proposed systems, in accordance with an exemplary embodiment of the invention.

Fig.6a

depicts/illustrates a graph comparing power losses between the conventional and proposed systems, in accordance with an exemplary embodiment of the invention.

Fig.6b

depicts/illustrates a bar chart comparing the average power losses between conventional and proposed systems, in accordance with an exemplary embodiment of the invention.

The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and/or detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

The embodiments herein below provide the details of a system and method for reducing power loss in a photovoltaic power station. The photovoltaic power station comprises a plurality of photovoltaic modules and inverters. A distance between one group of photovoltaic modules and a connected inverter is not equal to the distance between another group of photovoltaic module sand their respective inverter. As the distance varies, length of the electric cables connecting the photovoltaic modules with the inverter differs such as, for example, low, high, higher and highest. In general, power loss in the electric cables with greatest length is more when compared to the lowest length electric cables. Irrespective of the length of the electric cables connected between the photovoltaic modules and the inverter, the invention provides reduced power loss in the photovoltaic power station by connecting similar length electric cables into compartments of the inverters.

The photovoltaic modules with electric cables having same or similar length are grouped together. Subsequently, clustering of similar length electric cables accomplishes and the clustered similar length electric cables are connected to a compartment of the inverter. Similarly, each compartment of the inverter receives the clustered similar length electric cables from groups of photovoltaic modules comprising same or similar length electric cables. The inverter can comprise more than three compartments. Hence, by connecting the similar length electric cables to the compartments of inverter, power losses in the electric cables of the photovoltaic modules are reduced, thereby reducing overall power loss in the photovoltaic power station.

Referring now to the drawings, where similar reference characters denote corresponding features consistently throughout the figures, there are shown preferred embodiments.

Fig. 1 shows a network of devices 100, in accordance with various embodiments of the invention.

In a preferred embodiment, photovoltaic modules 102 comprising electric cables 104 are made into groups 106. Further, based on same or similar length of the electric cables 104, grouping of the photovoltaic modules 102 is accomplished. Electric cables 104 of similar length are clustered using clustering modules 108. An inverter 112 comprising three or more compartments 114 receives the clustered 110 electric cables 104 from the clustering modules 108.

With respect to Fig.1, each compartment 114 of the inverter 112 receives one cluster of electric cables 104, wherein each cluster comprises similar length electric cables 104.

Fig. 2 depicts a system illustrating connections between groups 106 of photovoltaic modules 102, electric cables 104 and compartments 114 of inverter 112 for reducing power loss in the photovoltaic power station.

In an embodiment, the photovoltaic power station comprises a plurality of photovoltaic modules 102. Each photovoltaic module 102 comprises electric cables 104 as output cables connected to the inverter 112 through the compartments 114. The length of the electric cables 104 from the photovoltaic modules 102 in the photovoltaic power station varies from one photovoltaic module 102 to the other. Further, based on whether the electric cables 104 in the photovoltaic modules 102 have the same or similar length, grouping of the photovoltaic modules 102 is carried out. Similar length electric cables 104 are clustered together through clustering modules 108. Each compartment 114 of the inverter 112 receives one cluster 110 of electric cables 104. Similarly, every compartment 114 of the inverter 112 receives clustered 110 electric cables 104. Therefore, each compartment 114 of the inverter 112 comprises similar length electric cables 104. In this manner, each inverter 112 present in the photovoltaic power station receives clustered 110 electric cables 104 from groups 106 of photovoltaic modules 102 comprising same or similar length electric cables 104.The length of the clustered 110 electric cables 104 in one inverter 112 may not be the same as compared to the clustered 110 electric cables 104 of another inverter 112 present in the photovoltaic power station. The length varies based on the distance and connection between the inverters 112 and the groups 106 of photovoltaic modules 102.

The advantage of clustering similar length electric cables 104 and connecting the clustered 110 electric cables 104 to each compartment 114 of the inverter 112 is that power losses in the electric cables 104 of the photovoltaic modules 102 are reduced. This in turn reduces overall power loss in the photovoltaic power station irrespective of the lengths of the electric cables 104.

Fig. 3 depicts a flowchart illustrating a method of reducing power loss in the photovoltaic power station. The photovoltaic modules 102 with same or nearby length electric cables 104 are made into groups 106, as depicted at 302. Clustering of the grouped electric cables 104 of same or similar length is carried out, as depicted at 304. The clustered 110 electric cables 104 are connected to the compartments 114 of the inverter 112, as depicted at 306. Each compartment 114 of the inverter 112 receives one cluster 110 of electric cables 104. By connecting the clusters 110 of electric cables 104 to the compartments 114 of the inverter 112, power loss in the electric cables 104 of the photovoltaic modules 102 is reduced, as depicted at 308.

Fig. 4a depicts/illustrates a graph comparing voltage drop in conventional and proposed systems, in accordance with an exemplary embodiment of the invention. Y- axis of the graph shows value of voltage drop in volts (V). X-axis of the graph shows length of the electric cables 104 from the photovoltaic module 102 to the inverter 112. Length of the electric cables 104 increases from lowest to highest, with respect to the increase in distance between the photovoltaic modules 102 and the inverter 112. The graph with darker grey line indicates conventional systems and the graph with lighter grey line indicates proposed system. When the values of voltage drop between the conventional and proposed systems are compared, the proposed system shows overall reduced voltage drop than the conventional system.

Fig. 4b depicts/illustrates a bar chart comparing the average voltage drop between the conventional and proposed systems, in accordance with an exemplary embodiment of the invention. The bar chart shows an average value of voltage drop in the conventional system as 14.032, whereas, the proposed system is having the average voltage drop value of 13.879. When compared, the voltage drop in the electric cables 104 of the photovoltaic modules 102 in the proposed system is lesser than the voltage drop occurring in the conventional systems.

Fig. 5a depicts/illustrates a graph comparing the percentage (%) voltage drop in conventional and proposed systems, in accordance with an exemplary embodiment of the invention. As depicted in fig. 4a, X–axis shows length of the electric cable 104 and Y-axis shows the percentage of voltage drop in volts (V). The voltage drop in conventional systems is projected as dark gray line in the graph and the light gray line indicates the voltage drop in proposed system. When both the voltage drop values are compared, the proposed system shows less percentage of voltage drop than the voltage drop occurring in the conventional systems.

Fig. 5b depicts/illustrates a bar chart comparing the average percentage (%) voltage drop between conventional and proposed systems, in accordance with an exemplary embodiment of the invention. The average percentage of voltage drop in conventional systems is 1.254, whereas, the proposed system has a lesser average voltage drop value of 1.240%.

Fig. 6a depicts/illustrates a graph comparing power losses between the conventional and proposed systems, in accordance with an exemplary embodiment of the invention. In the graph, X and Y – axis variables are with respect to length of electric cables 104 connected to the inverters 112 and value of power loss in watts (W), respectively. As depicted in fig.4a, the shades of grey line representing the conventional and proposed systems remain the same. This graph shows that the power loss in the proposed system is lesser than the power loss in the conventional systems.

Fig. 6b depicts/illustrates a bar chart comparing the average power losses between the conventional and proposed systems, in accordance with an exemplary embodiment of the invention. The average value of power loss in the conventional systems is given as 88037.733, whereas, the proposed system shows an average power loss value of 79833.598. When compared, the proposed system has overall lesser power loss than the power loss occurring in the conventional systems.

In an embodiment, the average value of voltage and power losses in the proposed system is calculated from the voltage and power losses occurring in the electric cables 104 connected between four inverters 112 and its respective groups of photovoltaic modules 102 present in the photovoltaic power station. The length of electric cables 104 increases with respect to an increase in the distance between the photovoltaic modules 102 and the inverters 112. Therefore, the average voltage and power losses are calculated from the electric cables 104 with low, high, higher and highest lengths. The values of power and voltage losses occurring in individual electric cables 104 are observed and an average of the observed values is calculated in the proposed system. The calculated result shows reduced voltage and power losses in the photovoltaic power station than the voltage and power losses occurring in conventional systems.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Claims

A system for reducing power loss in electric cables (104) of photovoltaic modules (102), said system comprising:
one or more groups (106) of photovoltaic modules (102) with electric cables (104) of same or similar length;
clustering modules (108) to cluster the electric cables (104) of same or similar length; and
inverters (112) with a plurality of compartments (114) for receiving the clustered (110) electric cables (104) at each compartment (114) of the inverter (112), thereby reducing power loss in the electric cables (104) of the photovoltaic modules (102).
The system as claimed in claim 1, wherein the inverter (112) comprises at least three compartments (114).
The system as claimed in claim 1, wherein the photovoltaic modules (102) with same or similar length electric cables (104) are grouped together to form one or more photovoltaic module groups (106) in the system.
The system as claimed in claim 1, wherein the electric cables (104) with similar length are clustered (110) to be connected to one compartment (114) of the inverter (112).
A method for reducing power loss in electric cables (104) of photovoltaic modules (102), said method comprising:
grouping the photovoltaic modules (102) with same or similar electric cable length;
clustering (108) the electric cables (104) with same or similar electric cable length; and
receiving the electric cables (104) at a plurality of compartments (114) of an inverter (112).
The method as claimed in claim 5, wherein the inverter (112) comprises at least three compartments (130).
The method as claimed in claim 5, wherein the photovoltaic modules (102) with the same or similar length electric cables (104) are grouped together to form one or more photovoltaic module groups (106).
The method as claimed in claim 5, wherein the clusters (110) of similar length electric cables (104) are connected to one compartment (114) of the inverter (112), thereby receiving clustered (110) electric cables (104) of similar length into each compartment (114) of the inverter (112).