WO2019097531A1 - Iot enabled switchgear distribution board - Google Patents

Abstract

An IoT enabled switchgear distribution board for per-line measurement of power consumption in subsidiary electrical circuits is disclosed. Said system comprises of current and voltage sensors to measure current and voltage in sub-circuits, wherein said readings are suitably sampled to compute the RMS value. The measured power and read current/voltage values in each sub-circuit is sent to the cloud in every 1-10 minutes interval, wherein it is further analysed.

Description

IOT ENABLED SWITCHGEAR DISTRIBUTION BOARD

TECHNICAL FIELD

[0001] The present invention, in general, relates to loT enabled devices to measure power consumption. Particularly, the invention relates to an loT device configured to perform per-line measurement of power consumption in electrical sub circuits. More particularly, the present invention relates to an loT enabled switchgear distribution board configured to measure power consumption per subsidiary circuit by non-invasive means wherein the measured data is transmitted to internet cloud server for further processing.

BACKGROUND ART

[0002] Various systems relating to power measurement and management are known in the state of the art literature. For example, US Pat No. 7539581 teaches a system and method for on-line monitoring and billing of power consumption. It measures energy usage on a power line wherein the measured data is transmitted in response to the request over the power line. But said method is not adapted for cloud computing. Also, said system is not suitable for independent power measurement and management in a premise.

[0003] US Pat No. 6487509 details a method for energy management in a domestic environment. It teaches a system wherein the power consumption of each appliance may be adjusted in accordance with the information that it receives and the way it is preprogrammed. It does not talk about a means to measure power consumption in a sub-circuit using non-invasive means.

[0004] WO2015107538 A2 details a system and method for digital energy metering and appliance control. But technical failure of one or more components of foe gateway device would affect its communication link with foe cloud, therein affecting foe data integrity. Also, said system is rather complex and expensive to maintain.

[0005] From the foregoing, it becomes apparent that there is a need for a system and method to perform per-line measurement of current as well as power consumption in an electrical circuit.

[0006] My invention proposes an loT enabled switchgear distribution board configured to dynamically measure power consumption per sub circuit in an electrical system. Said system uses non-invasive means to measure foe current and voltage in each sub-drcuit, wherein the measured data is transmitted to internet cloud server for further processing and analysis.

SUMMARY OF THE INVENTION

[0007] It is therefore the primary objective of the present invention to propose an loT enabled switchgear distribution board configured to perform per-line measurement of power consumption in subsidiary electrical circuits by non- invasive means.

[0008] It is another object of the invention to provide an loT enabled switchgear distribution board that is capable of reading the voltage and current consumed in a sub-circuit and transmit said data to the cloud for analysis.

[0009] It is yet another object of the invention to propose an loT enabled switchgear distribution board that may be retrofitted in an existing electrical circuit.

[0010] It is a further object of the invention to provide an loT enabled switchgear distribution board that is cost effective to manufacture and easy to maintain.

[0011] It is yet another object of the invention to provide a means to analyse load-wise consumption pattern in an electrical system.

[0012] Accordingly, the invention proposes an loT enabled switchgear distribution board configured to perform per-line measurement of power consumption in electrical sub-circuits, said board comprising of: • non-invasive current transformer (CT) adapted to be attached to the output of circuit breaker in each sub-circuit;

• an Analog to Digital converter wherein the output of each CT and voltage sensor is suitably sampled to compute the RMS values of current and voltage sensed in each sub-circuit; and

• processing unit comprising of at least one processor, configured to compute power consumed under each circuit breaker in a pre-set time interval, perform loT device management, and establish secure communication over WiFi, Wired LAN, Powertine Communication and/or GSM/GPRS/3G/4G radio networks;

[0013] The other objectives, features, and advantages of the present invention will become more apparent from the ensuing detailed description of the invention, taken in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

[0014] FIG.1 illustrates the schematic diagram of the system comprising of the loT enabled switchgear distribution board.

[0015] FIG.2 shows the loT enabled switchgear distribution board.

[0016] FIG.3 depicts the PU graph.

[0017] FIG.4 illustrates the interface showing usage comparison across different sub-circuits in an electrical Installation.

DESCRIPTION OF EMBODIMENTS

[0018] The preferred embodiments of the present invention will now be explained with reference to the accompanying drawings. It should be understood that however the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. The following description and drawings are not to be construed as limiting the invention and numerous specific details are described to provide a thorough understanding of the present invention, as the basis for the claims and as a basis for teaching one skilled in the art how to make and/or use the invention. However in certain instances, well- known or conventional details are not described in order not to unnecessarily obscure the present invention in detail.

[0019] The preferred embodiment of the present invention discloses an loT enabled switchgear distribution board for the per-line measurement of power consumption in an electrical circuit. In the present invention, each switchgear indicates a collection of multiple circuit breakers, each protecting a sub-circuit of an electrical installation.

[0020] On an loT enabled switchgear distribution board, an induction current sensor or a Hall Effect sensor is attached to each of the sub circuit lines in order to measure the current consumption. A voltage sensor reads the voltage values. The measured quantities are then passed over wire into an analog-to-digital converter located on a data communications enabled device with some data processing capability, wherein it produces a digital measurement of the per-line consumption. The measurements per line are then transmitted to an internet cloud server that stores foe consumption data.

[0021] This data can be further analysed for monitoring, operations and maintenance purposes A novel aspect of the invention is that granular electrical consumption data is made available unlike conventional switchgears, which provide no data at all on electricity consumption. This consumption data helps end consumers to understand their electricity consumption patterns and take specific actions to control consumption as well as preventive maintenance and replacement of circuitry and gadgets within their homes, commercial and industrial establishments.

[0022] Referring to FIG.1, a part of the preferred embodiment of the present invention teaches an in-switchboard installed loT device, wherein the current and voltage sensors and internet enabled processing device are pre-integrated into the switch gear distribution board or provided as an add-on plugin board to foe switch gear distribution panel. It could be installed at the time of constructing a building or retrofitted to the electrical circuit of an existing building.

[0023] As per the preferred embodiment of foe present invention, the current is measured using non-invasive AC current transformer attached to the power lines exiting from the circuit breakers, as shown in FIG.2. Voltage is measured using voltage sensors. The present invention uses SCT-013-000 Non-invasive AC current sensor transformer even though other similar CTs may be used and is included within the scope of the invention. The advantage of non-invasive current sensors is that it can be installed at any point in the circuit where power need to be measured.

[0024] Said CT is configured to sense a maximum of 100 A RMS and produces a corresponding output voltage of up to 50mv RMS. The output of CT and voltage sensors is fed to an Analog to Digital Converter (ADC), wherein it is suitably sampled to compute the RMS value of current and voltage sensed, and subsequently the power consumed is calculated. The power consumption is computed in five second intervals. In the preferred embodiment, ATmega328P is used as ADC, even though other ADC may be used and is included within the scope of the invention.

[0025] The steps involved in calculating the power is described herein: the voltage and current values from sensors are read through ADC pins as voltage variation, whereupon the samples are read from zero crossing after detecting the trough/peak of foe V/l wave form. DC offset is extracted by applying low pass filter, and subtract central signal on zero. The square values of voltage and current are summed and phase calibration is performed. Instantaneous power is computed as the product of phase shifted voltage and offset removed current value.

[0026] The system computes the number of times voltage crossed foe initial voltage for 20 iterations or maximum of 250ms, wherein the above-mentioned steps are performed for said number of iterations. Subsequently, Vrms and Irms are calculated, and the real power consumed is obtained.

[0027] Referring to FIG.2, the ADC output is connected to a Cortex A/M series ARM processor. Said processing unit has abilities for loT device management, firmware update over the air, device authentication, ability to interact with Wi-Fi, wired LAN, GSM/GPRS radio networks as well as powerline communication. The system has an internal clock to keep track of the time, wherein it is periodically synced with internet clock. The internal clock ensures that the time measurement is not affected even if a power failure occurs.

[0028] The measured power in each sub-circuit is sent to the cloud using WiFi, Wired LAN or powerline communication networks every 1 minute to ten minutes interval depending upon the amount of data collected and configuration setting for each device. Said data is sent to a central database through a hub server on the internet, as illustrated in FIG.1. Alternatively, the data could be sent using 4G/3G using GSM/GPRS radio networks.

[0029] The advantage of said system is that it is configured to measure the power consumption at defined levels of granularity. The system is also capable of recognising the power consumed by select appliances based on the instantaneous current drawn at the time of switching on of said appliances, or by reading load signatures that are specific to a given load connected to the power supply. User will be alerted on the website and/or mobile application when events such as spikes happen or when usage pattern significantly changes from past usage.The system also helps users to identify power consumption in different parts of a building remotely. Using this data, energy consumers can make decisions which will help drive efficiency in energy consumption.

[0030] As shown in FIG.3, the power consumption in each sub-circuit in the switchgear distribution panel is plotted against time dynamically. The power consumption is also statistically presented for user consumption.

[0031] Although the present invention has been described in connection with the preferred embodiments thereof with reference to the accompanying drawings, it is to be noted that various changes and modifications are possible and are apparent to those skilled in the art. Such changes and modifications are to be understood as included within the scope of the present invention unless they depart there from.

Claims

1. An loT enabled switchgear distribution board configured to perform per- line measurement of power consumption in electrical sub-circuits, said board comprising of:

• non-invasive current transformer (CT) adapted to be attached to the output of circuit breaker in each sub-circuit;

• an Analog to Digital converter wherein the output of each CT and voltage sensor is suitably sampled to compute the RMS values of current and voltage sensed in each sub-circuit; and

• processing unit comprising of at least one processor, configured to compute power consumed under each circuit breaker in a pre-set time interval, perform loT device management, and establish secure communication over WiFi, Wired LAN, Powerline Communication and/or GSM/GPRS/3G/4G radio networks;

2. The loT switchgear distribution board as claimed in claim 1 , wherein the measured power in each sub-circuit is sent to the cloud server for analysis in every 1-10 minutes interval, depending upon the amount of data collected and configuration setting for each device.

3. The loT switchgear distribution board as claimed in claim 2, wherein the analyzed data is stored in a central database.

4. The loT switchgear distribution board as claimed in claim 1 , wherein the scheduled events are tracked using an internal clock that is periodically synced with the internet clock.

5. A method to compute power consumed in a sub-circuit using non-invasive means, said method comprising the steps of:

• reading the voltage and current values from respective sensors through ADC pins as voltage variation;

• reading samples from zero crossing after detecting the trough/peak of the V/l wave form;

• extracting DC offset and subtract to centre signal on 0;

• performing phase calibration post summing the square values of voltage and current;

• computing instantaneous power;

• computing the number of times voltage crosses initial voltage in a pre-set time duration or a set number of iterations, wherein the previous steps of operation are repeated for said number of iterations; and

• calculating Vrms/lrms, and computing the real power consumed.

6. The method as claimed in claim 5, wherein power consumption is computed in pre-set intervals.