AU2020104384A4

AU2020104384A4 - A smart meter for design measurement and data collection for smart grid

Info

Publication number: AU2020104384A4
Application number: AU2020104384A
Authority: AU
Inventors: Anand Nayyar; Truong Van Truong
Original assignee: Individual
Current assignee: Van Truong Truong
Priority date: 2020-12-29
Filing date: 2020-12-29
Publication date: 2021-03-18
Anticipated expiration: 2028-12-29

Abstract

A smart meter for design measurement and data collection for smart grid, the meter comprises of a node station module in connection with an appliance for measuring current and voltage of the appliance by using a plurality of current sensors 102 and a voltage measurement circuit 104, a controlling unit 108 for converting measured current and voltage analog values into digital values for displaying on a display unit 110, and a first communication module 112 for transferring digital values of measured current and voltage to a base station module by a second communication module 112, a multi-function electric energy metering power monitor 114 for determining power and power factor of the appliance(s), a central processing unit 116 for converting determined power and power factor analog values into digital values, a real time clock 118 for providing pr6cised time and a memory module 120 for storing data. 22 - - - - - - - - - - - - - - - - - - - - - co . E cu0 00 oo 0 o 4JI 0. 2 0 0 u > ---- - -- - -- - -- - -- - -- - -- -

Description

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-- - -- - -- - -- - -- - -- - -- -- - A SMART METER FOR DESIGN MEASUREMENT AND DATA COLLECTION FOR SMART GRID FIELD OF INVENTION

The present invention generally relates to a field of the smart power grids, concretely relates to smart power grids system.

BACKGROUND OF THE INVENTION

Nowadays, countries are making a strong effort in Industry 4.0. Internet of Things (IoT) is one of the three main pillars of this revolution and is currently integrated into all aspects of development. IoT is applied in all areas of life: urban management, environmental monitoring, smart shopping, personal device management, smart meters, home automation. The development of IoT applications improves the quality of human life, especially in the field of household appliances. Electrical appliances are available in a wide variety of categories serving from the bedroom to the kitchen. The emergence of a large number of home appliances using electricity leads to significant challenges of effective power management. Efficient power management helps save energy resources, assess power consumption to make energy and cost-saving options, monitor power quality, and minimize risks.

Moreover, large-scale energy monitoring can provide valuable data resources to improve the electricity system's reliability and continuity and is considered an indispensable component in the Smart Grid system, which leads to the urgent need to design a reliable and intelligent electricity collection system. In recent years, lots of research is conducted towards the modification and enhancement of Smart Meter. Typically, the study describes the architecture of the smart power measuring system. The metering system must meet standards in terms of programmable following local conditions, measuring and transmitting electrical information, having communication ports with smart devices, reducing the load of power loss for the user.

A model of measuring power consumption using an AT89C51 processor was proposed. The system is designed to acquire all electrical parameters in real-time and communicate with other devices using the GSM link. It is a relatively viable model, cheap, and meets the specifications. Energy meter interfaced with microcontroller using interfacing middle wire device, namely Opto isolator. GSM modem interfaced with MCU using MAX232. The load is connected to the meter using a relay module. Information regarding the status of GSM modem communication with an energy meter, the load's status, energy consumed, SMS sent to GSM modem, the mobile number registered displayed on the LCD.

The only drawback of this is that there is no suitable management software, so the outstanding features of Smart Meter have not been exploited.

To propose, design, and implement a low-cost universal smart energy meter (USEM) with demand-side load management. The meter can be used in the postpaid and prepaid modes with flexible tariff plans such as time of use, block rate tariff, and their combination. The smart meter comprises of a potential transformer, current transformer, and microcontroller unit with an embedded communication module. The connectivity among the utility authority, the smart meter, and consumer is established by authority identification number, meter identification number, and user identification number using the cellular network. The load management option of the meter controls electrical loads and provides emergency power during the power shortage.

The proposed system can monitor electrical equipment with operating parameters 0 to 220V and 0 to 6A. It is suitable for home electrical equipment monitoring applications; In the case the electrical equipment needs to operate at a higher capacity, this system is not feasible. Measured results are communicated to smartphones via Wifi environment and stored on Cloud.

In an embodiment, the OSPPSM is modularly integrated, which means that, in the case of malfunction, parts can be replaced without affecting the general operation of this electrical measuring instrument (MI). In the first phase, the analog voltage and current sensors on the Arduino board of this electrical MI capture and process fundamental electrical variables, such as the voltage (v), current (i), and Power factor (cos <p). This is followed by the calculation of derived variables, active P, and reactive Q power. In a second phase, the Arduino board uploads the data to Firebase using a Wi-Fi connection. This OSPPSM receives two signals from the consumer unit to which it is connected: voltage and current. Each signal comes from the sensors, and is read through three analog inputs, including one for voltage and two for current.

However, the system possesses certain limitations. The system disclosed is observed not to be flexible and scalable in real-time operations. The measuring equipment is fixed to the number of inputs, i.e. the number of current sensor, which makes it impossible to expand the system. Some traditional interfaces such as RS485 cause limitations in this model, due to the multiple signal wires generated in the measurement network. The measuring node is usually connected one-to one with the meter. While in reality, switches and sockets for electrical equipment are scattered throughout the house and require a more flexible measuring system.

Specifications provided by the systems are incomplete and have not yet met the market demand. Most designs stop at home appliance monitoring with low current and voltage consumption, leading to the use of low-power sensors. There are many high-powered devices in use and should be managed by the Smart Meter system. Although it is an essential component in the Smart Grid system, data management is not integrated into surveyed systems. This software serves as the source for collecting and storing power consumption data. Based on a visual graph of the power consumption data over time, the user and the power supplier have reasonable load balancing plans.

In order to solve the above limitations, a novel power measurement system is proposed that ensures real-time measurement of current, voltage, power, power factor, and is capable of measuring multiple devices and communicates via RF, providing convenient assembly. Also, the system has a mechanism to automatically identify newly connected devices, which makes our model very flexible and easy to expand.

SUMMARY OF THE INVENTION

The present invention generally relates to a system and a method of designing smart meter for power grids that monitors and transmits real time data to a user's device.

In an embodiment, a smart meter for design measurement and data collection for smart grid, the meter comprising a node station module in connection with an appliance for measuring current and voltage of the appliance. The plurality of node station modules measures current and voltage of the appliances and is wirelessly connected with the base station module. wherein the node station module consisting of a plurality of current sensors for measuring the currents of the appliance(s), a voltage measurement circuit for measuring voltage of the appliance, a controlling unit for converting measured current and voltage analog values into digital values for displaying said measured current and voltage values on a display unit, and a first communication module for transferring digital values of measured current and voltage.

The system comprises of a process for measuring current and voltage of the appliance comprises setting hardware, node address, voltage offset, and sensitivity according to the rating of the appliance, measuring current and voltage of the appliance and thereby showing the measured current and voltage on a display unit and transmitting the measured current and voltage to controlling unit and central processing unit for determining current and voltage values and thereby sending to the server.

In an embodiment, a base station module wirelessly connected with the node station module through the first communication module for determining power and power factor of the appliance(s), wherein the base station module consisting of a second communication module for receiving the digital values of measured current and voltage, a multi-function electric energy metering power monitor for determining power and power factor of the appliance(s), a central processing unit for converting determined power and power factor analog values into digital values and thereafter determining newly connected devices automatically and identifying faults and provide information to the right repair process.

The node station module and base station module comprises of a universal serial bus for connecting appliance(s) and devices to the node station module and base station module in order to fetch data, a real time clock for providing pr6cised time and date with determined and measured values and a read only memory module for storing data of determined power and power factor along with current and voltage digital values.

In an embodiment, a Wi-Fi module for transferring data of determined power and power factor along with current and voltage digital values to a server, wherein the server allows user to access the data from anywhere anytime. a plurality of communication modules (radio frequency modules) must be assigned with a unique address for avoiding collision with other communication modules of the plurality of node station modules.

The system comprises of a process for data exchange comprises allowing user devices to send collected information to any electronic mail, wherein electronic mail includes daily power consumption report, automatically sending electronic mail for exceptional cases when amount of energy consumed exceeds the threshold in a day, posting tweets describing status when the amount of energy consumed exceeds the threshold in a day through a twitter function and alerting user device through push notification functions and exporting information as real-time data stream and sending data to user via email.

In an embodiment, a method for design measurement and data collection for smart grid, the method comprises measuring the currents and voltages of the appliance(s) at a node station by employing a plurality of current sensors and a voltage measurement circuit, converting measured current and voltage analog values into digital values for displaying said measured current and voltage values on a display unit, transferring digital values of measured current and voltage to a base station module through a first communication module, determining power and power factor of the appliance(s) by deploying a multi-function electric energy metering power monitor, converting determined power and power factor analog values into digital values and thereafter determining newly connected devices automatically and identifying faults and provide information to the right repair process and transferring data of determined power and power factor along with current and voltage digital values to a server in order to access the data from anywhere anytime.

An object of the present invention is to develop a system and a method for smart electricity meter.

Another object of the present invention is to develop a system that ensures real-time measurement of current, voltage, power, power factor.

Another object of the present invention is to develop a system is capable of measuring the power consumption of multiple devices, providing convenient installment.

Yet another object of the present invention is to develop a system for easy monitoring of the values on the web interface and smartphone interface.

To further clarify advantages and features of the present invention, a more particular description of the invention will be rendered by reference to specific embodiments thereof, which is illustrated in the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope. The invention will be described and explained with additional specificity and detail with the accompanying drawings

BRIEF DESCRIPTION OF FIGURES

These and other features, aspects, and advantages of the present invention will become better understood when the following detailed description is read with reference to the accompanying drawings in which like characters represent like parts throughout the drawings, wherein:

Figure 1 illustrates a block diagram of components installed in a system of a smart meter for design measurement and data collection for smart grid.

Figure 2 illustrates a flow diagram of a method of a smart meter for design measurement and data collection for smart grid.

Figure 3 illustrates a block diagram of the system architecture for a smart meter for design measurement and data collection for smart grid.

Figure 4 illustrates an exemplary view of a smart meter for design measurement and data collection for smart grid.

Figure 5 illustrates a characteristic representation of a current sensor for a smart meter for design measurement and data collection for smart grid.

Figure 6 (a) and 6(b) illustrates a node station model and a base station model for a smart meter for design measurement and data collection for smart grid.

Figure 7 (a) and 7(b) illustrates a circuit diagram of node station and base station components for a smart meter for design measurement and data collection for smart grid.

Figure 8 (a) and 8 (b) illustrates a schematic diagram for node station and PCB, base station and PCB for a smart meter for design measurement and data collection for smart grid.

Figure 9 (a) and 9 (b) illustrates a flow diagram of a node station and a base station for a smart meter for design measurement and data collection for smart grid.

Figure 10 illustrates a graphical representation of actual AC voltage from the transformer and analog signal conditioning output for a smart meter for design measurement and data collection for smart grid.

Figure 11 illustrates the tabular representation of address of the different registers used during data transmission.

Figure 12 illustrates different error codes for a smart meter for design measurement and data collection for smart grid.

Figure 13 illustrates an exemplary profile of management user interface for a user device.

Figure 14A and 14B illustrates an exemplary profile of a user interface for a cellphone.

Figure 15 illustrates a plurality of graphs of AC voltage, AC current, power, and power factor.

Figure 16 illustrates an exemplary profile of a case of smart PDM.

Further, skilled artisans will appreciate that elements in the drawings are illustrated for simplicity and may not have been necessarily been drawn to scale. For example, the flow charts illustrate the method in terms of the most prominent steps involved to help to improve understanding of aspects of the present invention. Furthermore, in terms of the construction of the device, one or more components of the device may have been represented in the drawings by conventional symbols, and the drawings may show only those specific details that are pertinent to understanding the embodiments of the present invention so as not to obscure the drawings with details that will be readily apparent to those of ordinary skill in the art having benefit of the description herein.

DETAILED DESCRIPTION

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.

It will be understood by those skilled in the art that the foregoing general description and the following detailed description are exemplary and explanatory of the invention and are not intended to be restrictive thereof.

Reference throughout this specification to "an aspect", "another aspect" or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrase "in an embodiment", "in another embodiment" and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

The terms "comprises", "comprising", or any other variations thereof, are intended to cover a non exclusive inclusion, such that a process or method that comprises a list of steps does not include only those steps but may include other steps not expressly listed or inherent to such process or method. Similarly, one or more devices or sub-systems or elements or structures or components proceeded by "comprises...a" does not, without more constraints, preclude the existence of other devices or other sub-systems or other elements or other structures or other components or additional devices or additional sub-systems or additional elements or additional structures or additional components.

Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings.

Figure 1 illustrates a block diagram of components installed in a system of a smart meter for design measurement and data collection for smart grid. The system is divided broadly into 2 parts i.e., a base station and a plurality of node station. The plurality of node stations is connected to each of the electrical appliances that are present in a user's premises. Each of the plurality of node station comprises of a plurality of current sensors 102 for measuring the current flowing through the system. The alternating current value is measured and calculated using the sensor (IC ACS712) based on a Hall effect. The hall effect current sensor 102 allows non-contact detection of direct and alternating currents, using a hall element, a magnet-electric converting element. Further, the hall effect minimizes power loss of the target current circuit and has a simple structure with high reliability. This hall effect current sensor 102 IC is easily integrated with MCU via an ADC connection with a shallow noise level. Its operating voltage is 5V, bandwidth is 50 kHz, and the total error is 4% at -40°C to 85°C.

In an embodiment, the plurality of current sensors 102 is interconnected to a voltage measurement circuit 104 for measuring the voltage difference occurring in each of the plurality of node stations. The voltage sensor is used to determine both the AC voltage or DC voltage level. The input of the sensor is voltage, whereas the output is a switch, an analog voltage signal, a current signal or an audible signal. When the current through the current sensor 102 has a definite value, a corresponding voltage value is generated according to the linear relationship. The voltage value is added to an offset voltage of Offset = VCC/2 to ensure that in the entire cycle, the measuring signal oscillates completely within the 0-VCC voltage range. The sensitivity of ACS712 ranges from 64 to 190 mV/A and depends on the specification of module.

In an embodiment, a controlling unit 108 is embedded in the system for analyzing the signals received from the input module and generating an output signal. The controlling unit 108 receive the input signal via an interfacing circuit that converts the input signal into a form that is accepted by the control unit. The operating voltage range of a microcontroller varies from 2.5v to 5.5v.

In an embodiment, a display unit 110 is connected to the controlling unit 108 for displaying the different parameters of voltage and current. The display unit 110 is installed in the user's end so that the user is able to see the current and voltage being consumed by the appliances and take necessary steps to control the over utilization of the energy. The display unit 110 include a LCD, user's mobile, Laptop, and other devices known in the art.

In an embodiment, a plurality of communication modules 112 is interconnected to the controlling unit 108 located at the node station and a central processing unit 116 located at a base station. The communication module 112 acts as a communication medium between the base station and the node station. The communication is embodied with a transceiver that transmits and receives the data between the two stations. The plurality of communication module 112 is either wired or wireless. The wireless communication module 112 used herein are RF module, Bluetooth and other such modules known in the art. The wired communication module 112 used herein is USB and other such similar modules based on the device of the user.

The RF communication module 112 used herein is NRF24L01 module that uses the Nordic Semiconductor NRF24L01+ chip, which improves the range, sensitivity, and data rate. This module integrates a full-duplex RF transceiver, operating at 2.4 GHz. The module configures up to 125 communication channels in the band 2400MHz to 2525MHz. The NRF24LO1 module interfaces with the Mesh network model, 250kbps to 2Mbit Data Rate, communication distance up to 200m. This module consists of the RF synthesizer and the base logic, including the shockburstTMhardware protocol accelerator. The module is easy to integrate with MCU via SPI protocol at low voltage from 1.9 ~ 3.6 V.

The wireless Bluetooth module used herein is HC-05 Bluetooth SPP (Serial Port Protocol) module with easy-to-use authentication and encryption mechanism. The HC-05 Bluetooth module works by default in Slave mode, and is configured to work in Master mode. The module operates in the 2.4 GHz band with CMOS technology and with AFH (Adaptive Frequency Hopping), Gaussian frequency-shift keying modulation, with selectable Baud rate UART: 1200, 2400, 4800, 9600, 19200, 38400, 57600, 115200, 160 kbps to 2.1 Mbps data rate. The common sensitivity of HC-05 is - 80dBm, RF transmission power up to + 4dBm with integrated antenna.

In an embodiment, an energy metering power monitor 114 is installed in the base station. The energy metering power monitor 114 used herein is PZEM-004T 114 which is a multifunctional module designed to measure current, voltage, power, and power factor for both AC and DC currents. The energy metering power monitor 114 stores the accumulated energy data before power off. The UART TTL MODBUS, communicates with a variety of terminal through the pinboard, reads and set the parameters. The working voltage of PZEM-004T is 80 ~ 260VAC, and measurement accuracy is 1.0 grade.

In an embodiment, a processing unit is installed in the base station that uses a Tensilica Xtensa Diamond Standard 106 Microprocessor and runs at 80 MHz. The processing unit used herein is

ESP8266 which is a very cheap module but offers a complete and closed Wi-Fi network solution. In many applications, the ESP8266 module acts as a Client connecting to an MQTT Broker service to perform two main tasks. The first task is to publish data to the MQTT Broker, and the second task is to subscribe to information from the MQTT broker, check the data, and perform command operations. The ESP8266 processor operates independently or integrated with MCU via SPI protocol. The module supports 64 KB boot ROM, 80 KB user data RAM, and 32 KB instruction RAM. The ESP8266 processor module operates at 2.4 GHz with 3.3V voltage.

In an embodiment, a real time clock 118 and a memory module 120 is interconnected to the central processing unit 116. The module integrates two modules. The first module is the real time clock 118 chip i.e., Maxim's DS1307, which is easily integrated with the controlling unit 108 via a 12C protocol. DS1307 provides real-time information with seconds, minutes, hours, days, days, months, and years. The DS1307 clock chip needs to be combined with a Lithium coin cell battery (CR1225) to maintain the correct time when the main power of the device is interrupted. A built in sensor module continuously monitors the status of the VCC to detect power outages and automatically switches to standby power. The second module is memory module 120 (Atmel's EEPROM 24C32), which communicates with the controlling via the 12C protocol, used to store data. When communicating with MCU, these two chips are set up with different addresses to avoid transmission conflict.

Step (202) involves measuring the current and voltages of the appliances at a node station by employing a plurality of current sensors 102 and a voltage measurement circuit 104. The current and voltage of the appliance is measured by setting hardware, node address, voltage offset, and sensitivity according to the rating of the appliance. The measured values are transmitted to the controlling unit 108 for determining current and voltage values and thereby sending to the server.

Step (204) involves converting measured current and voltage analog values into digital values for displaying the measured current and voltage values on the display unit 110. The current and voltage values are converted using an ADC and stored the current values are stored in an array. The display unit 110 used herein is a 16x2 LCD screen.

Step (206) involves transferring digital values of measured current and voltage to a base station module through a first communication module 112. The user devices send collected information to any electronic mail. The electronic mail includes daily power consumption report, automatically send electronic mail for exceptional cases when amount of energy consumed exceeds the threshold in a day and posting tweets describing status when the amount of energy consumed exceeds the threshold in a day through a twitter function.

Step (208) involves determining power and power factor of the appliance(s) by deploying a multi function electric energy metering power monitor 114. The values are determined using several theorem and mathematical equations using the input values of current and voltages.

Step (210) involves converting determined power and power factor analog values into digital values and thereafter determining newly connected devices automatically and identifying faults and provide information to the right repair process. Several error codes are assigned based on the type of error that occurs during the process for easy detection and diagnoses of the error.

Figure 3 illustrates a block diagram of the system architecture for a smart meter for design measurement and data collection for smart grid. The energy is being consumed by the user in the premises which is being monitored by the smart meter. The data being monitored is sent to a database for storing the data being send to the user. The data stored in the database is being sent to the user's device for information.

Figure 4 illustrates an exemplary view of a smart meter for design measurement and data collection for smart grid. The exemplary view shows the user interface that shows the different parameters in the user's device. The load consumes electrical energy and the consumed power is being calculated, stored and transmitted to the user's device.

Figure 5 illustrates a characteristic representation of a current sensor 102 for a smart meter for design measurement and data collection for smart grid. The current sensor ACS712 102 is used to sense the current passing through the circuit by using multiple input pins. The graphical representation of the output voltage versus sensed current is a liner graph which shows current is indirectly proportional to voltage.

Figure 6 (a) and 6 (b) illustrates a node station model and a base station model for a smart meter for design measurement and data collection for smart grid. The node station comprises of the current sensors 102, the voltage sensors, the power supply module 106, the controlling unit 108, the display unit 110, and the communication module 112. The plurality of sensors is connected to each of the appliance(s) to measure the current and voltage of the appliance(s). The converted signals are sent to the controlling unit 108 for analysis. The current and the voltage values and converted from the analog form to the digital form by using an Analog to digital converter embedded in the controlling unit 108. The measured values are displayed in the display unit 110. The measured values are then transmitted in the form of data packets by an 12C and a SPI protocols through wired and wireless medium from the node station to the base station. The current and voltage values received from the base station are analyzed and the power consumed by the appliance(s) are calculated by using a multi-function electric energy metering power monitor (PZEM-004T) 114. The data is transmitted to a central processing unit (Arduino Mega 2560) 116 via UART connection. The unit checks the accuracy of the data collected by comparing the total current measured at the base station, and the total current flows from the Nodes. The main station connects to the RF module via SPI protocol. The system is also equipped with a memory module (ROM) 120 and timing module (Real time clock) 118, communicating via 12C. The Each data packet at the base station gets added to real-time information and stored in ROM before being sent to the server (Thing Speak) via microchip and Universal Serial Bus. The values are further communicated to the registered user's device for user reference.

Figure 7(a) and 7(b) illustrates a circuit diagram of node station and base station components for a smart meter for design measurement and data collection for smart grid. The current sensor 102 is an 8-pin chip as an 'active shunt' for measuring ac/dc current levels up to 20 Amperes. The output of the ACS712 has a positive slope (>VIOUT(Q)) when an increasing current flow through the primary copper conduction path (from pins 1and 2, to pins 3 and 4), which is the path used for current sensing. The power supplied to the system is a DC supply that is being stepped down and converted to 3V-5V as per the system requirements.

The Bluetooth module is based on BC417 Single Chip Bluetooth IC that is compliant with Bluetooth v2.0 standard and with support for both UART, SPI and USB interfaces. The four pins of the Bluetooth module are sufficient for successfully enabling a wireless communication link but the modules produced now-a-days come with six pins namely: VCC, GND, TX, RX, EN and STATE.

EN: enable pin, when the pin is floating or connected to 3.3V, the module is enabled and when the pin is connected to GND, the module is disabled. +5V: supply pin for connecting +5V. GND: ground pin.

TX: It is the Transmitter pin of the UART Communication.

RX: Receive Pin of UART, STATE: status indicator pin. The pin goes LOW when the module is not connected to any device and when the module is paired with any device, this pin goes HIGH.

The RF communication module 112 uses 125 different channels which gives a possibility to have a network of 125 independently working modems in one place. Each channel can have up to 6 addresses, or each unit can communicate with up to 6 other units at the same time. The power consumption of this module is just around l2mA during transmission, which is even lower than a single LED. The operating voltage of the module is from 1.9 to 3.6V.

The controlling unit 108 uses an Analog-to-Digital (A/D) Converter module that has eight for the 40/44-pin devices. The conversion of an analog input signal results in a corresponding 10-bit digital number. The A/D module has high and low-voltage reference input that is software selectable to some combination of VDD, VSS, RA2 or RA3. The A/D converter has a unique feature of being able to operate while the device is in Sleep mode.

The voltage measurement circuit 104 includes a transformer connected to an AC input. The transformer steps down the voltage to a value required by the system. A plurality of resistors and diodes are connected in series and parallel combination in order to produce a desired output voltage that is to be fed to the ADC.

The LCD display unit 110 consists of multiple pins that interfaces with the controlling unit 108 through the known interfacing mediums for displaying the current and voltage consumed by the electrical appliances. The LCD unit 110 has characters from 0-9 and A-H and has the capacity to display up to 16 bits of data, 8 bits in each row.

The USB ISP consists of 10 pins, MOSI (multiple output single input), RESET, MISO (multiple Input Single Output) and other input pins. The output pins are VCC and ground. The FTDI comprises a plurality of pins that acts as a transceiver.

The Arduino Mega comprises plurality of I/O pins. Pins 54 to 69 is dedicated for ADC that converts analog to digital signal. Pin 70- VCC, Pin 71- ground, Pin 72- VCC (0-5V), Power regulator module, USB port, Pulse width modulator (PWM), and other communication pins.

The energy metering power monitor 114 (PZEM-004T) is bundled with 33mm diameter 100A current transformer coil having Measuring range:80-260V, Resolution: 0.V, Measurement

accuracy: 0.5%, voltage Measuring range: 0.00-1.00, Resolution: 0.01, Measurement accuracy:

1%, current Measuring range: 0-10A(PZEM-004T-10A); 0-100A(PZEM-004T-100A), Starting measure current: 0.01A(PZEM-004T-10A); 0.02A (PZEM-004T-100A), Resolution: 0.001A, Measurement accuracy: 0.5%.

The RTC & ROM module 118 has a maximum core clock speed of 33 MHz, 8-bit data processing, 1Kb internal SRAM and plurality of pins. The EEPROM has a power Supply: +3.3V, Current Consumption: 1OOmA, I/O Voltage: 3.6V (max), I/O source current: l2mA (max), Built in low power 32-bit MCU @ 80MHz, 512kB Flash Memory.

Figure 8(a) and 8(b) illustrates a schematic diagram for node station and PCB, base station and PCB for a smart meter for design measurement and data collection for smart grid. Printed circuit board or PCB is a circuit layout that is present in both node station and base station. The PCB of node station embeds the plurality of current sensor 102 connected to each load for measuring the current consumed by the appliance, the voltage measurement circuit 104 for measuring the voltage difference across the load, an AC-DC module for converting alternating current to direct current connected the power supply 106 module, the controlling unit 108 embedded with an ADC for converting the analog signal received from the sensors into digital values, an in-circuit serial programming chip for programming the controlling unit 108, the communication module 112 such as Bluetooth module and RF module for data transmission between the node station and the base station.

The PCB of base station comprises of the central processing unit 116 for analyzing the current and voltage values to extract the power consumed by the device and calculate the power factor of the device using the energy metering power monitor (PZEM004T) 114, the values are being sent to the memory module 120 for storing the values and simultaneously transmitted to the user's device and server through different wireless and wired communication module 112.

Figure 9(a) and 9(b) illustrates a flow diagram of a node station and a base station for a smart meter for design measurement and data collection for smart grid. Figure 9(a) illustrates the process flow of the node station. First, a mainboard initializes the initial value to the hardware, such as: 12C, SPI, ADC, UART, the port, node address, offset voltage, and sensitivity value.

Second, AC current and voltage data is being measured. The measured values are displayed in the display unit 110. The measured analog signals are converted to digital signals using the ADC. The digital values are transmitted wirelessly by checking the availability of channel in the communication module 112. The Atmega328P controlling unit 108 chip has l0bit ADC, corresponding to 1024 ADC steps. The reference voltage value is VCC = 5V = 5000mV. Let Vol be the output voltage of ASC712 going into the ADC, and so on

Vol = ADCnumber *5000(mV) (1) 1024

According to the datasheet of this IC, the value of alternating current is calculated by the formula: Vol AC Sensitivity *1000(mA) (2)

Each Node station uses ACS712-30A to perform a current device measurement. Node's operating voltage is 5000 mV, so the voltage offset is 2500 mV. The sensitivity of the ACS712-30A module is in the range of 64 - 68 mV/A, so here the average sensitivity is 66.

From formula (2), we obtain the current value as:

Vol- . Vol- 2500 66 IAC = Sensitivity *1000(mA)= *1000(mA) (3)

So the actual AC voltage is calculated by the formula:

VAC=k*(ADCa -ADC) (5)

Figure 9(b) illustrates the process flow of the base station. The hardware associated with the base station are initialized with a memory address. The digital values are received at the base station. The current and voltage values are analyzed using PZEM module. When the values received at the base station equals to the values at the node station, the data is being saved in the server. The data is being saved by adding a specific value (28) to the initial address of the data. If the resulting address exceeds a specific threshold address say 4088, the data is saved in the Read Only Memory module 120, else the address is initialized with a value '0'.

Figure 10 illustrates a graphical representation of actual AC voltage from the transformer and analog signal conditioning output for a smart meter for design measurement and data collection for smart grid. The actual alternating voltage value is from 80% to 115% of 300VAC, i.e., the nominal voltage value will be from 176V to 253V. To measure this voltage range, 300V-28VAC voltage transformer and voltage divider R2, R3 were used. To ensure a positive voltage level in all cycles, analog signal conditioning was utilized by adding 2.5V offset voltage to the AC signal. For standard 220V AC voltage taken from the grid, after adjusting to the 0 - VCC voltage range, the Arduino UART Terminal to determine two standard peak values are ADCmax and ADCmin. Let k be the corresponding conversion factor from 300VAC to the standard voltage: k 300 (4) ADC -ADCn

So the actual AC voltage is calculated by the formula:

VAc = k *(ADCa- ADCmin) (5)

Figure 11 illustrates the tabular representation of address of the different registers used during data transmission. To transmit a signal from every Node, the RF module is first given a unique address. The current values are stored in an array and attached to the packet for transmission with the specified address.

First, the main station initializes the initial value, such as SPI, UART, the port, and all of the node address. Second, the nRF24LO1 module receives data from all the nodes sequentially, with total current and voltage named Itotall and V, respectively. The PZEM-004T module measures total current Itotal2, voltage V2, and power factor 0 using UART Modbus-RTU protocol. The command format of the main station reads the measurement result is total of 8 bytes:

Slave Address + 0x04 + Register Address High Byte + Register Address Low Byte + Number of Registers High Byte + Number of Registers Low Byte + CRC Check High Byte + CRC Check Low Byte.

Figure 12 illustrates different error codes for a smart meter for design measurement and data collection for smart grid. When the Itotall and Itotal2, VI and V2 values are compared and are approximately the same, the system works well and when these values are different, the system encounters an error and needs to perform calibration checks. The table shows different codes for different type of errors occurred in Based on error code, the system requires appropriate troubleshoot actions for the administrator. Once the error has been fixed, the procedure gets repeated.

When all data received is correct, real-time data is to be added to the frame before storing on ROM 120. The 24C32 memory module 120 with a memory capacity of 4096 bytes is used to store data. Each node's current parameters, voltage, power, power factor, time are stored in 2 bytes, totaling 14 values in a data stream and has a capacity of 28 bytes. The address from 0 to 4088 to store data corresponding to 146 data lines is used, ESP8266 to send data to the Thing Speak server.

Figure 13 illustrates an exemplary profile of management user interface for a user device. Figure 13 illustrates a current voltage meter, an electric consumption meter, an electric consumption graph, a table consisting of voltage, current, PF, power, time and data values. Figure 13 further illustrates connection status along with a control dialogue box. The connection status shows real time connection status and a disconnect option for disconnecting the connected computer. The control dialogue box consisting of various options such as run, clear, pause, offline, and save.

Figure 14 A and 14 B illustrates an exemplary profile of a user interface for a cellphone. Figure 14A illustrate reports of the voltage data, first current data, second current data, and third current data in a graphical representation. Figure 14B illustrates line graph of afirst energy consumption node of at least three device and total energy consumption.

Figure 15 illustrates a plurality of graphs of AC voltage, AC current, power, and power factor. In AC voltage graph, the value of the voltage fluctuates in between 210 and 230 volts. In AC current graph, the value of the current fluctuates in between 0 to 2 amperes. In power graph, the value of the power fluctuates in between 0 to 400 watts. In power factor graph, the values of the power factor fluctuates in between 0 to 1.

Figure 16 illustrates an exemplary profile of a case of smart PDM. The case of smart PDM includes an AC input port, a device connecting port and a screen. A 3D printing technology is used to package boards for Smart PDM systems. The material used for manufacturing a case of smart PDM includes ABS (Acrylnitril Butadien Styrene) Filament. It is hard, solid but not brittle, insulating, waterproof, resistant to temperature and chemicals. The case of smart PDM is having 1.75 mm of resolution, 0 to 85degree Celsius operating temperature range, and 3.5 mm thickness of material layer. Furthermore, the case of smart PDM is having 2.5 cm of height, 100 cm of length, and 85 cm of width.

In an alternate embodiment, the system may be equipped with a module for analyzing a large amount of data effectively.

In an alternate embodiment, the system may be equipped with a control mechanism for load balancing and capacity factor enhancement.

The drawings and the forgoing description give examples of embodiments. Those skilled in the art will appreciate that one or more of the described elements may well be combined into a single functional element. Alternatively, certain elements may be split into multiple functional elements. Elements from one embodiment may be added to another embodiment. For example, orders of processes described herein may be changed and are not limited to the manner described herein. Moreover, the actions of any flow diagram need not be implemented in the order shown; nor do all of the acts necessarily need to be performed. Also, those acts that are not dependent on other acts may be performed in parallel with the other acts. The scope of embodiments is by no means limited by these specific examples. Numerous variations, whether explicitly given in the specification or not, such as differences in structure, dimension, and use of material, are possible. The scope of embodiments is at least as broad as given by the following claims.

Claims

WE CLAIM

1. A smart meter for design measurement and data collection for smart grid, the meter comprising:

a node station module in connection with an appliance for measuring current and voltage of the appliance, wherein the node station module consisting of a plurality of current sensors for measuring the currents of the appliance(s), a voltage measurement circuit for measuring voltage of the appliance, a controlling unit for converting measured current and voltage analog values into digital values for displaying said measured current and voltage values on a display unit, and a first communication module for transferring digital values of measured current and voltage;

a base station module wirelessly connected with the node station module through the first communication module for determining power and power factor of the appliance(s), wherein the base station module consisting of a second communication module for receiving the digital values of measured current and voltage, a multi-function electric energy metering power monitor for determining power and power factor of the appliance(s), a central processing unit for converting determined power and power factor analog values into digital values and thereafter determining newly connected devices automatically and identifying faults and provide information to the right repair process; and

a Wi-Fi module for transferring data of determined power and power factor along with current and voltage digital values to a server, wherein the server allows user to access the data from anywhere anytime.

2. The meter as claimed in claim 1, wherein the node station module and base station module comprises:

a universal serial bus for connecting appliance(s) and devices to the node station module and base station module in order to fetch data;

a real time clock for providing pr6cised time and date with determined and measured values; and

a read only memory module for storing data of determined power and power factor along with current and voltage digital values.

3. The meter as claimed in claim 1, comprising a plurality of node station modules for measuring current and voltage of the appliances, wherein the plurality of node station modules is wirelessly connected with the base station module.

4. The meter as claimed in claim 1, comprising a current measuring integrated chip capable of measuring large currents for high power devices such as refrigerators, washing machines, and the like., wherein the IC is easily integrated with controlling unit via an ADC connection with a shallow noise level, wherein operating voltage is 5V, bandwidth is 50 kHz, and the total error is 4% at -40°C to 85°C for the current measuring integrated chip.

5. The meter as claimed in claim 1, comprising a process for measuring current and voltage of the appliance comprises:

setting hardware, node address, voltage offset, and sensitivity according to the rating of the appliance;

measuring current and voltage of the appliance and thereby showing the measured current and voltage on a display unit; and

transmitting the measured current and voltage to controlling unit and central processing unit for determining current and voltage values and thereby sending to the server.

6. The meter as claimed in claim 1, wherein to transmit a signal from every node station module, a plurality of communication modules (radio frequency modules) must be assigned with a unique address for avoiding collision with other communication modules of the plurality of node station modules

7. The meter as claimed in claim 1, wherein the current values are stored in an array and attached to the packet for transmission with the specified address.

8. The meter as claimed in claim 1, comprising a process for data exchange comprises:

allowing user devices to send collected information to any electronic mail, wherein electronic mail includes daily power consumption report;

automatically sending electronic mail for exceptional cases when amount of energy consumed exceeds the threshold in a day;

posting tweets describing status when the amount of energy consumed exceeds the threshold in a day through a twitter function; and alerting user device through push notification functions and exporting information as real-time data stream and sending data to user via email.

9. The meter as claimed in claim 1, comprising hard, solid but not brittle, insulating, waterproof, resistant to temperature and chemicals a case of the node station module for protecting the node station module from environmental impacts.

10. A method for design measurement and data collection for smart grid, the method comprises:

measuring the currents and voltages of the appliance(s) at a node station by employing a plurality of current sensors and a voltage measurement circuit;

converting measured current and voltage analog values into digital values for displaying said measured current and voltage values on a display unit

transferring digital values of measured current and voltage to a base station module through a first communication module;

determining power and power factor of the appliance(s) by deploying a multi-function electric energy metering power monitor;

converting determined power and power factor analog values into digital values and thereafter determining newly connected devices automatically and identifying faults and provide information to the right repair process; and

transferring data of determined power and power factor along with current and voltage digital values to a server in order to access the data from anywhere anytime.

2020104384 29 Dec 2020

Current Sensors 102 PZEM004T 114

Voltage Sensor 104 Communication Central 112 116 module Processing unit Power supply 106 Real time clock 118

Controlling unit 108 memory 120 module Display unit 110

FIGURE. 1 measuring the currents and voltages of the appliance(s) at a node station by employing a plurality of 202 current sensors and a voltage measurement circuit converting measured current and voltage analog values into digital values for displaying said 204 measured current and voltage values on a display unit transferring digital values of measured current and voltage to a base station module through a first 206 communication module determining power and power factor of the appliance(s) by deploying a multi-function electric 208 energy metering power monitor converting determined power and power factor analog values into digital values and thereafter determining newly connected devices automatically and identifying faults and provide information 210 to the right repair process

FIGURE. 2

FIGURE. 3 FIGURE. 4

112

FIGURE. 5 FIGURE. 6a

FIGURE. 6(b)

FIGURE. 7(b) FIGURE. 7(a)

FIGURE. 8(a) FIGURE. 8(b)

FIGURE. 9(b)

FIGURE. 9(a)

FIGURE. 10 FIGURE. 11

FIGURE. 13 FIGURE. 12

FIGURE. 14 B FIGURE. 14 A

FIGURE. 16 FIGURE. 15