Solar Power Wireless Monitoring On Embedded Systems

Published Date: 02 Nov 2017

Abstract: To improve the utilization of solar power energy resources, Solar Power monitoring system is important. In this paper we discussed Data monitoring in solar power system is performed by combination of processor chip of ARM 7 family and GPRS wireless Communication. The ARM 7 processor LPC2148 is used for data automatic analysis, processing, displaying and saving automatically whereas GPRS wireless communication device is responsible for real time data transmission to the monitoring center. This system monitors the ambient temperature around solar power generation equipments, the Backplane temperature, and Humidity, solar irradiation, generated Current & Voltage. Here the system not only made the data transmission to the monitoring center in real time & effectively but also realize the unmanned watching[2].

Keywords-Data monitoring system; ARM 7; GPRS;

INTRODUCTION

Solar power is emerging as the number one competitive renewable energy resource. Improvement in the efficiency of solar systems and the need for a more developed understanding of solar panel performance, tracking and maintenance becomes increasingly important because of the rapid deployment of solar technologies in the marketplace.

Photovoltaic solar panels are increasing in popularity and users need accurate information of their solar energy installation. Currently, most residential solar panel systems only provide

energy information on a monthly basis and do not allow individual panel monitoring. PV solar panels last at least 25 years, whereas inverters only come with an 8-10 year warranty. That means that sometime in the 8-10 year range the inverter will die and the system will stop

producing energy. With a monitoring system in place the installer or homeowner will know immediately that the system has been compromised. Otherwise it could be weeks or months before the home owner looks at their energy usage statement from their utility company and realizes that their solar electricity system is not longer producing energy [8].

A study by solar expert conclude that about half of all power system aren’t working as they should, and this leads to around 20% of solar electricity to be lost [7]. To improve the utilization of solar energy resources, solar power monitoring systems is particularly important, Compared with traditional monitoring system, this system gives real-time high, reliable communications, no wiring, unattended, etc., and to achieve the network, intelligent, user friendly goals of solar power system monitoring.

The solar power monitoring systems consists of two modules: the master control module which has the microprocessor chip of ARM7 family for data acquisition, data processing, sending and Alarm functions the wireless Communication module adopts GPRS as the wireless communication device, which is responsible for real-time data transmission to the monitoring centre. Through the Combination of two modules, the remote power monitoring system is controlled effectively by the monitoring centre.

II. SYSTEM DESIGN

Solar power monitoring system collects the ambient temperature around solar power generation equipments, the backplane temperature, solar irradiance and other information to the master board by cable, the core processor LPC2148 is used for data automatic analysis, processing, displaying and saving automatic, if the power generation system in the exceptions, it will produce an alarm signal.

The whole system structure is shown in Fig1.

Fig.1 Block diagram of System structure.

THE EMBEDDED PROCESSOR ARM7

The LPC2148 microcontrollers are based on a 32/16 bit ARM7TDMI-S CPU with real-time emulation embedded trace support that combines the µc with embedded high speed flash memory ranging from 32 kB to 51 kB.

A 128-bit wide memory interface and unique accelerator architecture enable 32-bit code execution at the maximum clock rate. They are small size and have low power consumption [3].

The LPC2148 are ideal for applications where miniaturization is a key requirement, such as access control and point-of-sale. A blend of serial communications interfaces ranging from a USB 2.0 Full Speed device, multiple UARTs, SPI, SSP to I2Cs, and on-chip SRAM of 8 kB up to 40 kB , make these devices very well suited for communication gateways and protocol converters, soft modems, voice recognition and low end imaging. It has various 32-bit timers, single or dual 10-bit ADC(s), 10-bit DAC, PWM channels and 45 fast GPIO lines with up to nine edge or level sensitive external interrupt pins. Crystal Frequency is ranging from 1MHz to 30MHz and two low power mode i) Idle mode ii) Power down mode[9].

GPRS WIRELESS COMMUNI-

CATION

The monitoring system uses the GPRS wireless data transmission module, which is transparent for users, TCP / IP protocol stack is completely embedded. It has remote diagnostics, testing, regulatory functions, it meets the needs of data acquisition and data control between industry dispatch or control centre and a large number of remote sites [1].

Fig.2 Principle diagram of GPRS data preaching terminal

General Packet Radio Service is a new bearer service developed on the existing GSM system; the purpose is to provide packet data services in group for GSM users by using switched mode of network resources. The theoretical bandwidth of 171.2kbps, the practical application of it is about 40 ~ 100kpbs [5].

SOFTWARE DESIGN

The ARM 7 processor acquires the collected data from sensors constantly via sending the command word, and judges whether the data is normal, if the data is normal, it will be stored by the processor and transmits delay. Because GPRS uses traffic accounting, to a certain extent cost savings. If the alarm information is obtained by the Processor, the system sends data to the monitoring centre immediately .The main flow chart of system is shown in Figure 3. In the figure, parameters a, b, c, d, e, respectively, refer to the signal for the current sensor signal, voltage sensor signal, temperature signal, humidity signal, solar irradiance signal[2].

Fig.3 Flow diagram of system

VI. CONCLUSION

The solar power monitoring system could realize the accurate diagnosis and prevent faults from further expanding and improve reliability of photovoltaic power station.

GPRS wireless communications system is successfully applied to the ARM7 system, to achieving the rapid and accurate transmission of the parameters in a solar power generation system, to ensure that the devices can operate in the normal environment, and to achieve the solar power system network and unmanned watching.