WO2017130224A1

WO2017130224A1 - Intelligent inline sensor

Info

Publication number: WO2017130224A1
Application number: PCT/IN2017/050042
Authority: WO
Inventors: V Arunachalam
Original assignee: Tata Power Solar System Ltd.
Priority date: 2016-01-30
Filing date: 2017-01-28
Publication date: 2017-08-03

Abstract

An intelligent inline sensor for a PV string monitoring is incorporated inside an inline connector. The inline sensor is configured with a current/voltage measuring PCB to measure current/ data along length of a wire or cable connected to PV strings and various modules in a solar power generation system very close to the string. Further, the inline sensor may transmit the measured data to the remote monitoring devices, where each monitoring device includes Graphical User Interface (GUI) to indicate alert indications of functioning or non-functioning modules in the solar power generation systems. The GUI displays the data in graphical representation.

Description

Intelligent inline sensor

The invention generally relates to a wire harness used in the solar energy industry, more specifically to an intelligent inline sensor configured to measure current value or data along length of a wire or a cable electrically connected to PV strings and/or various modules of a solar power generation system. Such connector is also configured to transmit the data to monitoring devices.

In today’s world, power scarcity is one of the major problems that need to be resolved. In order to resolve this power scarcity, most industries are focusing on renewable sources of energy. Solar Energy is one of the most reliable renewable energy sources and PV modules and other solar energy utilization systems are designed to tap into this never ending energy source.

Generally, solar power generation systems have multiple solar panels stringed together for obtaining maximum power. Such stringing of solar or photovoltaic (PV) panels is carried out to combine one or more PV panels together in series or/and parallel. The output of the PV strings is connected to the combiner box to make it parallel, again the output of the combiner box is connected to the inverter to convert DC to AC power. The above connection between various components such as strings, junction box, combiner box, inverter, and batteries is electrical and achieved using cables, cable harness and standard connectors.

The components like junction box, combiner box, inverter, battery, and standard connector are configured with electrical components such as a conventional fuse to protect the other electrical components such as Integrated circuits, switches etc, of each module from overload current surge. Such fuse includes a metal string inside the fuse container to withstand only certain overload current surge. Such overload current surge may damage the electrical components and the modules/PV strings. In order to measure the overload current or voltage across each module, a conventional multi-meter is used to trace the continuity of flow of current or measure the voltage/current. Hence, it becomes difficult for an electrician or a solar technician to trace the damaged modules in a solar power generation system.

Additionally, there are elaborate current measuring/monitoring systems are installed to continuously monitor current across various components of a PV power generation system installation. Most of the current monitoring systems are installed at the combiner box level to measure the current across each PV strings or PV modules. The combiner box level usually has multiple channels of 8-channels and a current measurement device to measure the current from multiple channels/strings. Each channel/PV string is connected with another PV string or modules using cables or wires or harness to carry the current from one string/module to another string/module. Also, these combiner boxes are installed far away from the solar strings as it combines n number of strings together leading to multiple numbers of cables running into each combiner box thereby making the system more expensive and complex in tracing the continuity of current flow from one module/string to another module/string. A conventional fuse is used to protect the modules or PV strings from overload current surge. Hence, it becomes difficult task for the electrician or solar technician to trace the continuity of flow of current from one module/string to another module/string.

Hence, to overcome above-mentioned problems, there is a need for a simplified and more efficient system for measuring string data along length of a wire or cable in a PV installation and transmit such data to monitoring devices. Additionally, the system should be efficient and cost effective which may be monitored very close to the PV string, in a way that multiple strings can be paralleled at the string level and single cable output can be taken out.

Object of Invention

The object of the invention is to provide an intelligent inline sensor, incorporated inside an inline connector, which measures current/voltage value or data along length of a wire or cable connected to a photovoltaic (PV)string. Another object of the invention is to transmit the measured data to the monitoring devices using wired/wireless communication. Such monitoring device allows for easy and efficient monitoring of current/voltage in a PV string.

Accordingly, the invention talks about an intelligent inline connector device comprising of an inline sensor circuit disposed within the connector configured to measure current/voltage along the length of a wire. The device has two electrical coupling means to enable conductivity between the inline sensor circuit and the connector and also, a wireless communication module is disposed within the inline connector where the module is configured to transmit the current/voltage readings to an external device.

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. 1depicts/illustrates details of front view of an inline connector with an intelligent inline sensor, in accordance with an embodiment of the invention.

Fig. 2depicts/illustrates details of front view of an intelligent inline sensor, in accordance with an embodiment of the invention.

Fig. 3 depicts/illustrates details of a system configuration for measuring and monitoring of current/voltage via a current/voltage measuring PCB and monitoring device(s) respectively, in accordance with an embodiment of the invention.

Fig. 4 depicts/illustrates details of front view of a T-Branch connector configured with inline connectors, in accordance with an embodiment of the invention.

Fig. 5 depicts/illustrates the nature of graph of plotted against current in PV strings versus measured output voltage of PV Strings.

The embodiments herein, 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 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 an intelligent line sensor for PV string monitoring. The intelligent inline sensor incorporated inside an inline connector and the inline sensor is configured with a current/voltage measuring PCB to measure current/voltage value or data along length of a wire or cable connected to photovoltaic (PV) strings and various modules in a solar power generation system. For an instance, the components such as solar arrays or solar modules or solar strings, junction box, combiner box, inverter, and a battery, are electrically connected with a wire or cable. Further, the intelligent inline sensor may transmit the data to one or more monitoring devices, where the monitoring device includes Graphical User Interface (GUI). The GUI indicates alert indications of functioning components or non-functioning components or both. The GUI displays the data as graphical representation. Thus, by using the monitoring device the solar technician or electrician may find the functioning or non-functioning components in the solar power generation system. Here the non-functioning components are nothing but the non-working or malfunctioned modules due to overload current surges or short circuit or shadow. Further, the functioning components are nothing but the working of the components in the solar power generation system.

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

Fig. 1 depicts front view of an inline connector 100 with an intelligent inline sensor 140, in accordance with an embodiment of the invention. The connector 100 includes a male connector 110 coupled to a female connector 120, an intelligent inline sensor 140 coupled to a sensor holder 130 which is placed in between the male connector 110 and the female connector 120along the symmetry axes of the connector 100. For an instance, the symmetry axes may be horizontal axis –X of the connector 100. Such placement of the holder 130 and the inline sensor 140 provides an ease access for technician, electrician, or user to remove, replace, or fix the defective string140. Further, the holder 130 is configured to hold the inline sensor 140 in it.

Referring to Fig. 1, both ends of the holder 130 and the inline sensor 140 is electrically connected 104 to both the male connector 110 and the female connector 120. For an instance, the electrical connection 104 that acts as a conducting layer is formed inside the

connector

110 and 120 by the process of soldering or by using metal made of alloys that are attached to both ends of the holder 130 and the inline sensor 140. Such conducting layer ensures continuity of flow of current across the connector 100. In one embodiment, one end of the electrical wire 102 is connected to one of the modules such as PV string etc and another end of the electrical wire 102 is connected to the male connector 110. The power generated from the PV string is sent via the electrical wire 102 to carry the flow of current. Such current passes through the holder 130 and the inline sensor 140. As both ends of the holder 130 and inline sensor 140 is electrically connected 104 to ensure the continuity of such flow of current through the inline sensor 140.The current further flows through an electrical wire 106 that is connected to the components such as a combiner box/inverter etc. In yet another instance, the inline sensor 140is configured to measure the current received from PV string via the wire 102 and wirelessly transmit the measured data to monitoring devices (not shown in the Fig.1). Hence, such inline sensor 140 measures the current/voltage along length of the wire or cable electrically connected to the PV string modules and/or various components, where the length of the wire or cable depends on the distance between each PV string module and/or components installation.

In one embodiment, referring to Fig. 1, the inline sensor 140 may have at least one lead externally connected to each end of the inline sensor140. Each lead exactly fits into a provision provided in each of the

connector

110 and 120. Such provisions are used for connecting a monitoring device to measure current value from the inline sensor140 and monitor the fault of the components. A small lead along with the input / output wire will be used as a wired communication medium to transmit the data from the PCB via leads to the monitoring device.

Fig. 2 depicts/illustrates detail of front view of an inline sensor 200, in accordance with an embodiment of the invention. The inline sensor 200includes a cartridge210 and a current/voltage measuring PCB 220 incorporated inside the cartridge 210. The cartridge 210 includes a plurality of closing lids (212, 214) attached to both ends of the cartridge 210. For an instance, the cartridge 210 may be a hollow cylindrical or rectangular shaped cartridge 210, and the closing lids (212, 214) may be of cylindrical or rectangular shaped(212, 214) that exactly fits at both the ends of the hollow cylindrical or rectangular shaped cartridge 210. The PCB 220 is placed inside the cartridge 210 along horizontal axis –X of the connector. Both ends of the PCB 220 are electrically connected 204 to the center of the interior ends of the lids (212, 214).For another instance, the electrical connection204 can be made of materials such as metal, alloys, and combination thereof. Such arrangements of electrical connections204 with the PCB 220 and the lids (212, 214) will ensure the continuous flow of current across the connector. Thus, PCB 220measures current and/or voltage values/data.

For example, an electrical wire is connected to one of the components such as PV string and another end of the electrical wire 102 is connected to the connector 110. The PV string generates DC power, and this power is sent via electrical wire to carry the flow of current. Further, the current flows towards another end of the wire that is connected to the connector 110 with a holder and cartridge 210. The current received at one end of the closing lid 212 flows towards the PCB 220 via the electrical connection 204. On receiving the flow of current, the PCB 220 starts measuring the current or voltage values, and wirelessly transmits the data to the monitoring devices (not shown in the Fig.2). Further, the same current flows to another end of the lid 2 via the electrical connection 204. Furthermore, the current flows toward the electrical wire connected to the other components such as a combiner box/inverter etc.

In one embodiment, referring to Fig. 2, the inline sensor 200 may have at least one lead externally connected to each lid (212, 214) of the inline sensor 200. Each lead fits exactly into provisions provided in the male and female connector. Such provisions are used for connecting a monitoring device that measure current/voltage value from the sensor 200 and monitor the fault of the PV string module. Further, such leads are used as a wired communication medium to transmit the data from the PCB 220 to the monitoring device.

Fig. 3 depicts/illustrates details of a system configuration 300 for measuring and monitoring of current via a current/voltage measuring PCB 220 and monitoring device(s) 310 respectively, in accordance with an embodiment of the invention. The measuring PCB 220 includes a sensor 302 electrically connected 304 to a communication module 306, where the sensor 302 can be a current-measuring sensor or a voltage-measuring sensor or both. The electrical connection 304 is printed conductive tracks on Printed Circuit Board (PCB) with one or multiple copper layers used to connect the sensor 302 and the communication module 306. For an instance, the output of the sensor 302 is an analog signal, which is converted into a digital signal and transmitted via wired/ wireless communication module 306.

Referring to Fig. 3, the sensor 302 detects the current received from the PV string via the electrical wire connected to the male connector and converts the current into a measured analog output voltage. Such analog voltage signal is given as input to an ADC to convert the analog voltage into digital voltage data. Such data is wirelessly transmitted using the wireless device to the monitoring devices(s) (not shown in the Fig. 3).

Referring to Fig. 3, the monitoring device(s) 310 includes Graphical User Interface (GUI). Once the device (310) receives the data, the GUI configured will indicate alert indications of functioning or non-functioning components. Further, the GUI displays the data as graphical representation. Thus, the monitoring device helps a solar technician or electrician to find the functioning or non-functioning components in the solar power generation system. Here the non-functioning components are nothing but the non-working or malfunctioned components due to overload current surges or short circuit or shadow. Further, the functioning components represent the working of the components in the solar power generation system.

Fig. 4 depicts/illustrates details of front view of a T-Branch connector 400 configured with inline connectors 100, in accordance with an embodiment of the invention. The T-branch connector 400 includes one or more “input connectors” 100 that are coupled to one side of a bus bar 410 and at least one “output connector “100 is coupled to another side of the bus bar 410. The T- branch connector 400 includes one or more “input connectors” 100 to receive inputs from the solar modules such as one or more PV strings. The output of the “input connectors” 100 are connected in parallel to the connector bus bar 410. The output of the bus bar 410 is the summation of all individual powers obtained from individual “input connectors” 100. Hence, the bus bar 410 acts as a summer component to add the entire individual input sources connected in parallel and sends summed output. Further, the output of the bus bar 410 is given as an input to the “output connector” 100 and further the output of the “output connector” 100 is connected to one of the components such as combiner box/inverter. Such “output connector” 100 may act as a buffer to receive the input from one source and send the output to another source without changing the characteristics of the input.

In one embodiment, the intelligent inline sensor 140 can either be placed inside the “input connectors” 100 or input/output side of a bus bar 410.

For an instance, T-connector 400 may be used to receive the inputs from one or more “input connectors” 100. The output of the bus bar 410 is the summed power of all individual power received from individual “input connector” 100. The output of the bus bar 410 is given as the input to the “output connector” 100 and the output of the “output connector” 100 are connected to one of the components such as combiner box/inverter. In another instance, the T-Branch connector may be configured with different combinations such as “4 input connectors and 1 output connector”, “ 3 input connectors and 1 output connector”, “6 input connectors and 1 output connector” etc.

It is also pertinent to note that the present invention may be applicable to various types of connectors such as diode connector or fuse connector or simple harness etc.

Experimental tests were carried out using the device as claimed herein. In an exemplary embodiment, data from five PV strings of solar modules are collected and represented. The specifications of system of PV strings used are given in tabel.1

Parameter	Value
Number of strings tested	5
Maximum Current(I_mp) of each string	8.31 A
Short circuit current(I_sc) of each string	8.83 A
Open circuit voltage(V_oc) of each string	37.4 V
Maximum Voltage (V_mp) of each string	30.1V
Measurement	Digital output (0 - 5 V)

The output data of said system of PV strings are represented in below table2, which includes PV string current shown on a multi-meter and output voltage measured by the inline sensor.

String 1		String 2		String 3		String 4		String 5
Shown on Multimeter(A)	Shown through sensor (V)	Shown on Multimeter(A)	Shown through sensor (V)	Shown on Multimeter(A)	Shown through sensor (V)	Shown on Multimeter(A)	Shown through sensor (V)	Shown on Multimeter(A)	Shown through sensor (V)
6.1	2.29	6.1	2.29	6	2.25	6	2.25	6	2.25
6.2	2.33	6.1	2.29	6.1	2.29	6.1	2.29	6.1	2.29
6	2.25	6	2.25	6	2.25	6	2.25	6	2.25
5.8	2.18	5.9	2.21	5.8	2.18	5.8	2.18	5.8	2.18
5.9	2.21	5.9	2.21	5.9	2.21	5.8	2.18	5.9	2.21
4.3	1.61	4	1.50	4.3	1.61	4.3	1.61	4.3	1.61
4.3	1.61	4.3	1.61	4.3	1.61	4.3	1.61	4.3	1.61
3.8	1.43	3.6	1.35	3.7	1.39	3.8	1.43	3.8	1.43
5.8	2.18	5.8	2.18	5.8	2.18	5.8	2.18	5.8	2.18
6	2.25	5.9	2.21	6	2.25	6	2.25	6	2.25
5.9	2.21	5.9	2.21	5.9	2.21	5.9	2.21	5.9	2.21
6.1	2.29	5.9	2.21	6.1	2.29	6.1	2.29	6.1	2.29
6.2	2.33	6.1	2.29	6.2	2.33	6.2	2.33	6.2	2.33
6.2	2.33	6.2	2.33	6.2	2.33	6.2	2.33	6.2	2.33

In an exemplary embodiment, Fig. 5 shows the nature of graph 500plotted against current in PV strings versus measured output voltage of PV Strings for the values represented in table.2. The Fig shows the nature of current in PV strings measured by the multi-meter 510 and the nature of measured output voltage by inline sensor 512. It is evident from the fig.5 that the measurement or data received by the sensor is more accurate and dependable.

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

An intelligent inline connector device comprising:
an inline sensor circuit disposed within said connector configured to measure current/voltage along the length of a wire;
atleast one electrical coupling means to enable conductivity between said inline sensor circuit and said connector; and
a wireless communication module disposed within said inline connector said module configured to transmit said current/voltage/any other parameter readings to an external device.
The device of claim 1 wherein said inline sensor circuit is covered by an outer cartridge.
The device of claim 1 wherein said inline sensor circuit covered by said cartridge is disposed within a sensor holder.
The device of claim 1 further comprising of a male connector coupled with a female connector with a sensor holder disposed in between said male and said female connector wherein said sensor holder configured to hold said sensor circuit.
The device of claim 1 wherein said inline sensor circuit is disposed horizontally along x-axis of said connector.
The device of claim 2 wherein said outer cartridge is a hollow cylinder.
The device of claim 2 wherein said outer cartridge further comprising closing lids at both the ends.
The device of claim 1 wherein multiple said connectors are connected to form a T-branch connector wherein said T-branch connector is configured with two or more inputs and atleast one output.
The device of claim 8 wherein said T-branch connector is configured to measure power from multiple PV string of a PV module and combine said measurement to show a single reading.
The device of claim 8 wherein said T-branch connector further comprising a bus bar configured to add power from said multiple input connectors and send summed output power to said output connector.
The device of claim 8 wherein said T-branch connector further comprising of said inline sensor circuit either disposed within said connector or disposed within said bus bar.
The device as claimed in claim 1 wherein said electric coupling means is soldering or metal alloy connections.
The device as claimed in claim 1 wherein said external device is configured with a GUI to show measured current and/or voltage measured by said in-line sensor circuit.