Web-based Net Energy Meter for Grid Connected PV System

Web-based Net Energy Meter for Grid Connected PV System Syafii Syafii, Muhammad Ilhamdi Rusydi, Lovely Son, Irvan Zikri Electrical Engineering Department, Faculty of Engineering, Universitas Andalas, Padang, Indonesia Abstract ? The web-based PV system monitoring to measure electrical production and consumption to the load or utility grid is presented in this paper. This monitoring system consists of an Arduino Mega 2560 with two PZEM 004T sensor modules. The monitoring system has been designed to store measurement data of current, voltage, power and energy in the database and display on the webpage in real time and infographics history. The PZEM sensor measurement has been tested with an average power difference 0.29% less than IEC-61724 minimum-accuracy. Realtime data is obtained in the form of one-line data for every 2 seconds, with a data size of 375-byte and 75ms delivery delay. For one day period testing, the electrical energy that can be generated by the PV system is 5,925 kWh, while the power consumed by the load is only 1,272 kWh so the accumulated electrical energy that can be exported is 4.65 kWh. The test results show that the system has been able to measure net energy export or import by the PV system to utility grid. Keywords ? Web-based PV monitoring, Arduino PZEM sensors, and Grid connected PV system. 1. Introduction Increasing electricity demand affects in diminishing energy reserves. Indonesia, with the greatest potential for solar energy through the government regulation No. 14, 2012 provides an opportunity for owners to connect their PV Systems into national utility network. DOI: 10.18421/TEM91-06 https://doi.org/10.18421/TEM91-06 Corresponding author: Syafii Syafii, Electrical Engineering Department, Universitas Andalas. Email: syafii@eng.unand.ac.id Received: 26 September 2019. Revised: 24 December 2019. Accepted: 06 January 2020. Published: 28 February 2020. ⓒ 2020 Syafii Syafii at al; published by UIKTEN. This work is licensed under the Creative Commons Attribution?NonCommercial?NoDerivs 3.0 License. The article is published with Open Access at www.temjournal.com Utilization of PV system in distribution network requires bidirectional power meter to evaluate the amount of electrical energy produced and the burden used to reduce electricity bill. Therefore, the utilization of communication technology, sensors, and information to distributed generation metering and control are the topics of interest in the development of future smart grid [1],[2]. Several previous studies have discussed various techniques for electrical energy production and consumption monitoring. The research on integrated data-acquisition system for photovoltaic blocks mutualization monitoring using LabView [3], remote monitoring system based on GSM data communication network for rural areas [4], LoRa wireless sensor networks [5],[6] and web-based through internet networks [7],[8], have been done and reported. In a study conducted in [9], a Web- Scada was implemented to monitor and control solarwind hybrid generator systems remotely through the internet and based on LabView software via RS232 serial communication [10]. The connection to the internet network is done through a server computer with communication between sensors, remote terminals, and the server computers in the study use serial communication wired networks and Local Area Networks. This paper presents the proposed web-based net energy meter system using two PZEM 004T modules based on Arduino microcontroller. The monitoring system is designed in real time measurement and record in historical online data. So that the data obtained can be monitored anytime anywhere and saved for further analysis. The electrical data from the power produced by the PV system and the power used in the load demand with the utility grid are obtained through PZEM 004T sensors measurements. The results of this study are expected to help obtain the use of electrical energy and energy generated by PV system in real time and historical online data, displayed on websites that can be accessed anytime and anywhere, so as to optimize the use of electrical energy to be more efficient.   TEM Journal. Volume 9, Issue 1, Pages 37?41, ISSN 2217?8309, DOI: 10.18421/TEM91?06, February 2020. TEM Journal ? Volume 9 / Number 1 / 2020. 39 system components consist of two parts, namely testing with hardware and testing with software. The system hardware is tested based on the installation of Arduino Mega 2560 and PZEM 004T pins or cables that are following the design. The system software tested using Arduino IDE and Google Chrome Developer Tools. The Arduino program tested using Arduino IDE using monitor serial output parameters, while on servers and clients it is tested using Google Chrome Developer Tools software with output parameters on the network. The overall system is designed as shown in Fig. 2 below. Figure 2. Web-based Net Energy Meter Real Circuit 4. Result and Discussion The PZEM 004T test used to determine the sensor configuration system with the Arduino Mega 2560 microcontroller. This aim has been achieved. The operation of the sensor required four TTL cables consisting of one 5V voltage operating cable, one ground cable, and a pair of cables that function as senders (TX) and data receivers (RX) with serial communication lines as shown in Fig. 3. Figure 3. Schematic diagram of PZEM 004T Hardware testing is carried out by installing cables directly through GND, TX, RX, and VCC pins on pins that are available on Arduino Mega 2560. Installation of two or more PZEM 004T requires a project board to connect in parallel between VCC pins and GND. The PZEM Pin connection is shown in Table 1. PZEM 004T (1) is installed in Arduino Mega 2560 Serial 2, and PZEM 004T (2) is installed in Arduino Mega 2560 Serial 1 while VCC and GND on each sensor are connected in parallel through the project board. When the Grid tie inverter successfully synchronizes with low voltage distribution grid, then PZEM 004T (1) and (2) will directly transmit voltage, current, power and energy data to Arduino Mega 2560 as real digital values. Table 1. PZEM Connection Component Init Pin Final Pin Note PZEM 004T (1) VCC VCC on project board 5 V GND GND on project board negative polarity of circuit TX Pin 17 Arduino (RX Serial 2) PZEM 004T (1) Transceiver data to Arduino RX Pin 16 (TX Serial 2) Receiver data of PZEM 004T (1) from arduino PZEM 004T (2) VCC VCC on project board 5 V GND GND on project board negative polarity of circuit TX Pin 19 (RX Serial 1) PZEM 004T (2) Transceiver data to Arduino RX Pin 18 (TX Serial 1) Receiver data of PZEM 004T (2) from arduino The PZEM 004T digital reading is done by the serial communication with Arduino Mega 2560 to get the amount of voltage, current, power and energy as show in Fig. 4. By the comparison of PZEM 004T measurement and Hioki 3286-20 Clamp Meter, can be concluded that the PZEM 004T sensor (1) and (2) have worked well because the measured value is close to the measured value of Hioki 3286-20 Clamp Meter with an average power difference of 0, 29%. Based on IEC-61724 standard [11] this value is acceptable because the accuracy is less than 1 %. Therefore, data obtained from current, voltage, power and energy of PZEM sensor can be used for PV system monitoring. Figure 4. Data read by PZEM 004T Data obtained from each sensor will be stored in the Arduino Mega 2560 program variable. The     TEM Journal. Volume 9, Issue 1, Pages 37?41, ISSN 2217?8309, DOI: 10.18421/TEM91?06, February 2020. TEM Journal ? Volume 9 / Number 1 / 2020. 41 The accumulation of power collected for a certain time will be calculated as energy. The measurement results have been displayed in the form of infographics to show the composition of energy use and energy production as well as net energy in one day period from 05/21/2019 to 05/22/2019 as shown in Fig. 6. For one day measurement the energy that can be generated by the PV system is 5,925 kWh, while the power consumed by the load is only 1,272 kWh, so the accumulated electrical energy that can be exported is 4.65 kWh. 5. Conclusion The net energy meter system has read voltage, current, power and energy generated at the inverter output terminal and load terminal using the PZEM 004T sensors. Based on these data the net energy export to utility or import from utility can be determined. This system is equipped with a data logger feature, so the measurement data can be directly recorded on the client computer. The PZEM 004T obtained data have a good level of accuracy with an average power difference of 0.29% compared with Hioki 3286-20 clamp meter. For one day measurement the energy that can be generated by the PV system is 5,925 kWh, while the power consumed by the load is only 1,272 kWh so the accumulated electrical energy that can be exported is 4.65 kWh. 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