Power Research

Sudhakar H. S. ¹, Indira M. S. ², Gujjala B. Balaraju ³, Siddhartha Bhatt M. ⁴

Affiliations
1 Junior Research Fellow, EATD, Central Power Research Institute, Bangalore-560080, IN
2 Principal, Sir M Visvesvaraya Institute of Technology, Bangalore-562 157, IN
3 Electrical Appliances Technology Division, Central Power Research Institute, Bangalore-560080, IN
4 Energy Efficiency and Renewable Energy Division, Central Power Research Institute, Bangalore-560080, IN

Abstract

Performance of a SPV system is dependent on temperature, array configuration, solar insolation, shading etc. The conversion of solar energy using SPV modules,change in insolation conditions which severely affect the efficiency and output power of the modules. Improvement in the efficiency of conversion of solar energy can be done by tracking the maximum power point of a PV module. Various types of MPPT charge controllers are available in the market. A dc-dc converter is an important component of a SPV system as it acts as an interface between the load and the SPV module. These dc-dc converters enhance the performance of the MPPT algorithms leading to an improvement in the overall efficiency of the SPV system. This paper presents the modeling and simulation of one diode equivalent circuit of solar photovoltaic module using MATLAB/SIMULINKTM along with the boost converter which gives an efficiency of 93.29%.

Keywords

Maximum Power Point Tracking (MPPT), Solar Photovoltaic (SPV) Characteristics, Boost Converter

Full Text

     

H. S. Sudhakar ¹, M. S. Indira ², Gujjala B. Balaraju ³, M. Siddhartha Bhatt ⁴

Affiliations
1 Junior Research Fellow, EATD, Central Power Research Institute, Bangalore - 560080, IN
2 Principal, Sir M Visvesvaraya Institute of Technology, Bangalore - 562 157, IN
3 Electrical Appliances Technology Division, Central Power Research Institute, Bangalore - 560080, IN
4 Energy Efficiency and Renewable Energy Division, Central Power Research Institute, Bangalore - 560080, IN

Abstract

Battery is an electrochemical energy storage device that converts chemical energy into electricity, by use of a galvanic cell. The paper presents operation of lead acid battery, its chemical reactions and the charging methods to improve its performance and life span. The constant current charging mode results in overcharging of the battery as it is being pushed at full current. The constant voltage charging mode takes more time to charge the battery fully due to float charge, but the battery will not overcharge improving the life span. If the lead acid battery is undergoing deep discharge repeatedly then the life span of the battery will be less than its rated value. The operating temperature also has bearing on the life span. The paper is also presents the introduction to battery management system (BMS,) which is the heart of the battery system. The BMS involves a sophisticated supervisory control and data acquisition system (SCADA) with data management, control, protection and prediction.

Keywords

Valve regulated Lead Acid (VRLA), Ampere hour (Ah), constant current charging, constant voltage charging

Full Text

     

Gujjala B. Balaraju ¹

Affiliations
1 Electrical Appliances Technology Division, Central Power Research Institute, Bangalore-560080, IN

Abstract

With growing population, economic and industrial development, the need to examine alternative sources for generating electricity has become very important and the gap between Electrical power demand and supply in the country is increasing, so it is essential to have efforts to conserve the electricity by using energy efficient electrical products. There is always a possibility to save energy by proper usage of energy efficient components to minimize the wastage of energy in electrical appliances. The standards & labeling programme was launched for Air conditioners and Refrigerators by Bureau of Energy Efficiency (BEE) during May 2006 on voluntary basis to minimize these wastages. The manufacturers started displaying the star labels on the products from March 2007. The programme was made mandatory from January 2010. In order to verify the correctness of the star labels,BEE has introduced the check testing of the refrigerators and Air conditioners. The star rating evaluation involves the measurement of energy consumption & volume with gross & storage volume of the refrigerator along with pull down test as qualification requirement. The process of determining the energy rating consists of measuring the tested energy consumption of the refrigerator. From December 2013 to July 2014, 15 numbers of refrigerators were check tested as per BEE requirements by CPRI. The star rating of each of the models are calculated from the tests carried out at CPRI. Out of these 74% of the tested refrigerators meet the star rating claimed by the manufacturer.

Keywords

Bureau of energy efficiency (BEE), star label, star rating, comparative energy consumption (CEC)

Full Text

     

H. S. Sudhakar ¹, Gujjala B. Balaraju ¹, K. Pradeep ², M. Siddhartha Bhatt ²

Affiliations
1 Electrical Appliances Technology Division, Central Power Research Institute, Bangalore-560080, IN
2 Energy Efficiency and Renewable Energy Division, Central Power Research Institute, Bangalore-560080, IN

Abstract

Performance of a SPV system is dependent on temperature, array configuration, solar insolation, and shading across it. Shading can occur when the PV arrays/modules get covered by shadows of passing clouds, buildings, etc., or even by shadows cast by other modules/arrays. As a result the ideal operation of the PV systems is severely affected the P-V and I-V characteristics. The modeling of nonlinear current-voltage characteristics of solar cells for performance prediction becomes difficult under the influence of shading. Non-uniform solar radiation due to shadows casted by the other panels/ modules, buildings, clouds, etc. can cause maximum power to change drastically. Partial shading of PV installations has an impact on its power production. For the simulated results it has been observed that 74.66% loss in I-V characteristics and 85.41% loss in P-V characteristics respectively. The power losses in the individual shaded cells would result in local heating and create thermal stress on the entire module/array resulting in hot-spot formation.

Keywords

Maximum power point tracking (MPPT), Partial shading, Solar photovoltaic (SPV) characteristics.

Full Text

     

Sudhakar H. S. ¹, Gujjala B. Balaraju ¹, Pradeep K. ²

Affiliations
1 Electrical Appliances Technology Division, Central Power Research Institute, Bangalore-560080, IN
2 Energy Efficiency and Renewable Energy Division, Central Power Research Institute, Bangalore-560080, IN

Abstract

Performance of a SPV system is dependent on temperature, array configuration, solar insolation, shading across it etc. The conversion of solar energy using SPV modules comes with its own problems that arise from the change in insulation conditions. These changes in insulation conditions severely affect the efficiency and output power of the SPV modules. For improving the efficiency of conversion of solar energy can be done by tracking the maximum power point of a PV module. There are so many types of MPPT charge controllers for doing this important work in SPV system. A dc-dc converter is essential in SPV system as it acts as an interface between the load and the SPV module. Three different basic types of converters are explained in this paper without any non-idealities. There are other types of dc-dc converters as well, but these converters from these three basic converters. Further by using these dc-dc converters the performance of the MPPT algorithms can be done for improving the overall efficiency of the SPV system.

Keywords

Maximum power point tracking (MPPT), Solar photovoltaic (SPV) characteristics, DC to DC converter

Full Text

     

H. S. Sudhakar ¹, Gujjala B. Balaraju ¹, Pradeep K. ², Siddhartha Bhatt M. ²

Affiliations
1 Electrical Appliances Technology Division, Central Power Research Institute, Bangalore-560080, IN
2 Energy Efficiency and Renewable Energy Division, Central Power Research Institute, Bangalore-560080, IN

Abstract

In large PV hybrid power systems, battery management is critical due to the continuous operation of the power system, the limited power available for temperature control in the battery room, and the high cost of maintenance.Charge controllers are required in solar or wind power generating systems where electrical energy storage is required in these systems. Optimal charging is required in order to improve the performance and life of the batteries. The charge controllers are used for optimal charging of the entire system. The different types of charge controllers, terminologies, set points and importance of hybrid system are explained in this paper. The shunt and series type charge controller’s current and voltage regulations are shown and battery current and voltage characteristics according to the source availability and load applied are also shown for the understanding.The studies of a system of the three sources (Solar, wind and diesel generator) includes than it in practice to optimize performance by 35% by optimal charging of battery using charge controller

Keywords

Charge controller, Shunt type controller, Series type controller

Full Text

     

H. S. Sudhakar ¹, Gujjala B. Balaraju ¹, K Pradeep ², M. Siddhartha v ²

Affiliations
1 Electrical Appliances Technology Division, Central Power Research Institute, Bangalore - 560 080, IN
2 Energy Efficiency and Renewable Energy Division, Central Power Research Institute, Bangalore-560 080, IN

Abstract

MPPT algorithms are necessary in PV applications because the MPP of a solar panel varies with the irradiation and temperature, so the use of MPPT algorithms is required in order to obtain the maximum power from a solar array.Over the past decades many methods to find the MPP have been developed and published. These techniques differ in many aspects such as required sensors, complexity, cost, range of effectiveness, convergence speed, correct tracking when irradiation and/or temperature change, hardware needed for the implementation or popularity, among others. Among these techniques, the P&O and the In Cond algorithms are the most common. These techniques have the advantage of an easy implementation but they also have drawbacks, as will be shown later. Other techniques based on different principles are fuzzy logic control, neural network, fractional open circuit voltage or short circuit current, current sweep, etc. Most of these methods yield a local maximum and some, like the fractional open circuit voltage or short circuit current, give an approximated MPP, not the exact one. In normal conditions the V-P curve has only one maximum, so it is not a problem. However, if the PV array is partially shaded, there are multiple maxima in these curves.

Keywords

Battery Energy Storage System, Maximum Power Point, Optimal Charging

Full Text