Solar Power Charge Controller - Case Study Example

Anastasia N. Other (name optional) SID: 9999999 MOD002791 Final Project Final Project Report BSc (Hons) Computer Science (Substitute above line with correct course and delete this italicized line) Submitted: Month Year 1. Introduction Improvement in human life and creating a balance between the environment and human obligations are important (Li, Hui, and Lai, 2013). The continuous development means continuous innovation and creativity. An example of such development is solar power aimed at complementing available sources of energy (Rani, Ilango, and Nagamani, 2013). Solar energy incorporates different components and requires the presence of sunlight (Li, Hui, and Lai, 2013). The paper discusses solar power and the overall approach is to present the components, which contributes to effectiveness in harvesting sunlight and mechanism used to protect these components (Rani, Ilango, and Nagamani, 2013). Uncontrolled energy is dangerous for the equipment and individuals utilizing the solar. It means effective maintenance and associated capacities are important. For example, creating an effective maintenance system is important, and it is the focus of the discussion (Li, Hui, and Lai, 2013). The paper also discusses other variables which influence solar production and harvesting solar energy (Rani, Ilango, and Nagamani, 2013). For instances, batteries and PV panels are crucial while inverters and charge controls are also important. Advancing a discussion on these different components is important in ensuring the right conclusions are made. 1.1. Aims of the Study The following are the aims of the study: i. To understand the different components that contributes to solar power production ii. Appreciate terminologies and working together on different components to allow production of energy iii. The relationship of different components and its divergent tasks in solar power and charge controller 1.2. Background Energy continues to become an important component in advancing the technological needs and requirements (Rani, Ilango, and Nagamani, 2013). People and other entities continue to seek sources of energy, and the renewable energy continues to gain traction (Perez et al., 2013). The climate change and associated environmental changes mean the institutions have to embrace alternative sources of energy and imperative to analyze the components that form the solar system (Fakham, Lu, and Francois, 2011). The solar system is made of different components and features, which have to connect and work together (Fakham, Lu, and Francois, 2011). A single component cannot operate without some of the important features. It is imperative to analyze the contribution of these components in accomplishing the solar power requirements (Datta et al. 2011). Some of the features and factors include solar power, charge controller, charge controller types and equalization among others. 2. Literature Review 2.1. Solar Power The technological advancement has resulted in the introduction of new technologies and measures which are targeted towards improving the capacities and capabilities of humans (Fakham, Lu, and Francois, 2011). One of such technology is the solar power, which uses sun rays to produce energy (Li, Hui, and Lai, 2013). The solar power converts sunlight into electricity through concentrated solar power or using photovoltaics (PV) (Rani, Ilango, and Nagamani, 2013). The concentrated solar power utilizes mirrors or lenses and tracking systems to concentrate sun rays into a small beam while the photovoltaic cells utilize photovoltaic effect into the production of electric current (Monteiro et al. 2012). To accomplish the production of solar power production, numerous products and services are required. 2.2. Charge Controller A solar charge controller sometimes called a solar panel regulator is an important component that is integral to the solar charging systems with systems producing more than 10W (Fakham, Lu, and Francois, 2011). The purpose of charge controller is to protect the battery from overcharging. It also protects the panel from problems such as reverse current flow (Lo, Chen, and Chang, 2011). In addition, if the system has a low voltage disconnect facility, the charge controller also protects draining of the battery (Rani, Ilango, and Nagamani, 2013). It prevents the current from flowing to the solar panel during the night, and also it prevents solar charging kit damage (Yilmaz and Krein, 2013). Different sizes of charge controllers exist which are rated in terms of voltage: 24V, 12V, and 6V targeting solar panels that are rated up to 60A (Rani, Ilango, and Nagamani, 2013). Moreover, there are solar controllers that are designed for dual battery systems, which enables the charge to be used as a starter battery and for leisure. Another important use of charge controller is monitoring the battery voltage (Boico and Lehman, 2012). The charge controller detects when the battery voltage is low, when the voltage is below certain limits, the charge controller disconnects the system (Kim, Kim, and Kim, 2011). Disconnecting the load from the battery means that the battery is protected from being drained completely (Kassem and Hamad, 2011). It is imperative to note a completely drained battery does not operate in the usual capacities due to the damages to the system (Bhandari et al., 2014). Therefore, the charger controller is targeted towards protecting the battery from fluctuating voltage and overall protection of the solar power system. 2.3. Charge Controller Types Maximum Power Point Tracking (MPPT) and Pulse Width Modulation (PWM) are the two common types of charging methods, which enables charging of batteries. Even though the names are different, both technologies are appropriate for off-grid solar industry and both options are efficient (Fakham, Lu, and Francois, 2011). The decision to utilize any of the highlighted technologies does not lie on the regulators or which method is better (Rani, Ilango, and Nagamani, 2013). Rather, it involves the determination of the controller that operates effectively with the system design. To understand the difference between these charge controllers, it is imperative to analyze the PV panel power curve (Messai et al. 2011). The power curve is crucial since it states that expected power generation is achieved through a combination of current (I) and voltage (V) generated by the panel (Hoke and Maksimović, 2013). In the situation whereby there is an optimal ratio of voltage to current, it is called Maximum Power Point (MPPT), and it keeps fluctuating throughout the day. 2.4. Pulse Width Modulation The technology is appropriate when the battery bank is full. The aim of any solar system is to make the controller allow passage of enough current to the voltage storage system (Fakham, Lu, and Francois, 2011). In the time when the target voltage is about to be reached, the charge controller alternates between connecting the battery bank to the battery to the panel and keeps connecting and disconnecting depending on the amount of voltage (Kadirvel et al. 2012). It regulates the voltage in ensuring the battery are maintained appropriately while the PV array is also maintained (Manju, Ramaprabha, and Mathur, 2011). The switching and alternation in connection ensure the battery bank is charged accordingly while also protecting the PV panel/array is not overcharged (Rani, Ilango, and Nagamani, 2013). Thus, pulse width modulation protects the PV arrays and ensures the battery is charged accordingly (Fakham, Lu, and Francois, 2011). The following is an image of use of PWM in solar system design and operation: Source (Phocos, 2016) The PWM controllers usually operate near the maximum power pint and mostly above it. The following graph illustrates the operating range: Source (Phocos, 2016) 2.5. Maximum Power Point (MPPT) The design of MPPT features an indirect connection between the battery bank and the PV array (Fakham, Lu, and Francois, 2011). Some of the components, which makes up the indirect connections include a DC/DC that contributes to converting the excessive PV voltage and converting into extra current without the loss of efficiency. The following image presents the graphical connections of an MPPT, with other components to generate solar energy (Fakham, Lu, and Francois, 2011). Source (Phocos, 2016) To accomplish its operations, MPPT controllers employs an adaptive algorithm that allows for maximum power point of the PV array (Fakham, Lu, and Francois, 2011). It then adjusts the continuously flowing voltage resulting in the maintenance of the most efficient among of power for the designed systems (Rani, Ilango, and Nagamani, 2013). The following image presents the PV curve when the MPPT is used: Source (Phocos, 2016) 2.6. Equalization Equalizing is sometimes called conditioning batteries refers to the strategy of charging deep cycle of wet cell batteries that is targeted at extending battery life, revive the efficiency of the battery and restoration of battery capacity (Traube et al. 2013). The strategy is the application of controlled overcharge cycle to improve the efficiency of the wet batter but requires certain precautions and procedures have to be followed. When a battery is in the process of discharging, the sulfuric acid reacts with lead plates resulting in the production of chemical reaction translating the production of lead sulfate and electricity (Fakham, Lu, and Francois, 2011). When the user decides to recharge the battery, the process is reversed resulting in the conversion of lead sulfate back into sulfuric acid and lead (Rani, Ilango, and Nagamani, 2013). However, the conversion process is not 100% effective meaning some lead sulfate remains on the plates (Kadirvel et al. 2012). If these residual sulfates are retained for long, it usually crystallizes or hardens translating in the reduction of the batteries capacities. It results in destroying of the batteries and increasing its internal resistance to produce an adequate amount of power (Delucchi and Jacobson, 2011). Batteries in standby condition for long periods, the electrolyte, stratifies layers of acid and water in each of the cells (Rani, Ilango, and Nagamani, 2013). The water remains at the top while the water moves downwards, which also affects the efficiency and capacity of the batteries. Numerous stages exist in equalization process. The first step is the verification of the battery that is flooded in type. The second approach is the removal of all the loads from the battery. The third approach is connecting to the battery charger (Kadirvel et al. 2012). The fourth stage is setting charger for the equalization voltage process. The fifth phase is starting the charging batteries. The sixth stage is evidence of bubbling and gassing vigorously (Fakham, Lu, and Francois, 2011). The seventh stage is taking frequent gravity readings to determine whether the equalization process is proceeding appropriately (Rani, Ilango, and Nagamani, 2013). The eight stage is accomplishing the equalization through ensuring the gravity values does not change. 2.7. Low Voltage Disconnect A low voltage battery disconnect is a type of a circuit that will automatically turn-off the load connected to the battery when a situation in which the battery voltage falls beyond certain levels (Fakham, Lu, and Francois, 2011). The aim of the prevention strategy is to ensure the battery lasts for long and the low voltage battery disconnect is used to achieve the identified requirement (Rani, Ilango, and Nagamani, 2013). Thus, the purpose of the low voltage disconnect is to ensure the battery is protected and sometimes the low voltage disconnect is available in the inverters utilized in the solar system requirements (Fakham, Lu, and Francois, 2011). 2.8. Summary The harvesting of solar energy brings incorporates different components, and these components have to be maintained effectively. For example, the charge control is important in protecting the different devices. In addition, there are different types of charge control which are applicable to different situations. The design and connection of different components and apparatus inform on the type of charge control. Other processes such as equalization and low voltage disconnect are crucial. Equalization is aimed at ensuring the electrodes improves capacity while the low voltage disconnect is aimed at protecting the system from spoilage because of decrease beyond certain levels. References Bhandari, B., Lee, K.T., Lee, C.S., Song, C.K., Maskey, R.K. and Ahn, S.H., 2014. A novel off-grid hybrid power system comprised of solar photovoltaic, wind, and hydro energy sources. Applied Energy, 133, pp. 236-242. Boico, F. and Lehman, B., 2012. Multiple-input maximum power point tracking algorithm for solar panels with reduced sensing circuitry for portable applications. Solar Energy, 86(1), pp.463-475. Datta, M., Senjyu, T., Yona, A., Funabashi, T. and Kim, C.H., 2011. A frequency-control approach by photovoltaic generator in a PV–diesel hybrid power system. IEEE Transactions on Energy Conversion, 26(2), pp.559-571. Delucchi, M.A. and Jacobson, M.Z., 2011. Providing all global energy with wind, water, and solar power, Part II: Reliability, system and transmission costs, and policies. Energy Policy, 39(3), pp.1170-1190. Fakham, H., Lu, D. and Francois, B., 2011. Power control design of a battery charger in a hybrid active PV generator for load-following applications. IEEE Transactions on Industrial Electronics, 58(1), pp. 85-94. Hoke, A., and Maksimović, D., 2013, August. Active power control of photovoltaic power systems. In Technologies for Sustainability (SusTech), 2013 1st IEEE Conference on (pp. 70-77). IEEE. Kadirvel, K., Ramadass, Y., Lyles, U., Carpenter, J., Ivanov, V., McNeil, V., Chandrakasan, A., and Lum-Shue-Chan, B., 2012, February. A 330nA energy-harvesting charger with battery management for solar and thermoelectric energy harvesting. In 2012 IEEE International Solid-State Circuits Conference (pp. 106-108). IEEE. Kassem, A. and Hamad, M., 2011, April. A microcontroller-based multi-function solar tracking system. In Systems Conference (SysCon), 2011 IEEE International (pp. 13-16). IEEE. Kim, J., Kim, J. and Kim, C., 2011. A regulated charge pump with a low-power integrated optimum power point tracking algorithm for indoor solar energy harvesting. IEEE Transactions on Circuits and Systems II: Express Briefs, 58(12), pp. 802-806. Li, X., Hui, D. and Lai, X., 2013. Battery energy storage station (BESS)-based smoothing control of photovoltaic (PV) and wind power generation fluctuations. IEEE Transactions on Sustainable Energy, 4(2), pp. 464-473. Lo, K.Y., Chen, Y.M. and Chang, Y.R., 2011. MPPT battery charger for stand-alone wind power system. IEEE Transactions on Power Electronics, 26(6), pp. 1631-1638. Manju, B.S., Ramaprabha, R. and Mathur, B.L., 2011, March. Modelling and control of standalone solar photovoltaic charging system. In Emerging Trends in Electrical and Computer Technology (ICETECT), 2011 International Conference on (pp. 78-81). IEEE. Messai, A., Mellit, A., Guessoum, A. and Kalogirou, S.A., 2011. Maximum power point tracking using a GA optimized fuzzy logic controller and its FPGA implementation. Solar energy, 85(2), pp. 265-277. Monteiro, V., Pinto, J.G., Exposto, B., Gonçalves, H., Ferreira, J.C., Couto, C. and Afonso, J.L., 2012, October. Assessment of a battery charger for electric vehicles with reactive power control. In IECON 2012-38th Annual Conference on IEEE Industrial Electronics Society (pp. 5142-5147). IEEE. Perez, E., Beltran, H., Aparicio, N. and Rodriguez, P., 2013. Predictive power control for PV plants with energy storage. IEEE Transactions on Sustainable Energy, 4(2), pp. 482-490. Phocos. (2016). Comparing PWM & MPPT Charge Controllers. Available at: http://www.phocos.com/na/wp-content/uploads/sites/6/2015/12/Guide-Comparing-PWM-MPPT-Charge-Controllers.pdf Rani, B.I., Ilango, G.S. and Nagamani, C., 2013. Control strategy for power flow management in a PV system supplying DC loads. IEEE Transactions on Industrial Electronics, 60(8), pp. 3185-3194. Traube, J., Lu, F., Maksimovic, D., Mossoba, J., Kromer, M., Faill, P., Katz, S., Borowy, B., Nichols, S. and Casey, L., 2013. Mitigation of solar irradiance intermittency in photovoltaic power systems with integrated electric-vehicle charging functionality. IEEE Transactions on Power Electronics, 28(6), pp. 3058-3067. Yilmaz, M. and Krein, P.T., 2013. Review of battery charger topologies, charging power levels, and infrastructure for plug-in electric and hybrid vehicles. IEEE Transactions on Power Electronics, 28(5), pp. 2151-2169. Read More

The solar system is made of different components and features, which have to connect and work together (Fakham, Lu, and Francois, 2011). A single component cannot operate without some of the important features. It is imperative to analyze the contribution of these components in accomplishing the solar power requirements (Datta et al. 2011). Some of the features and factors include solar power, charge controller, charge controller types and equalization among others. 2. Literature Review 2.1.

Solar Power The technological advancement has resulted in the introduction of new technologies and measures which are targeted towards improving the capacities and capabilities of humans (Fakham, Lu, and Francois, 2011). One of such technology is the solar power, which uses sun rays to produce energy (Li, Hui, and Lai, 2013). The solar power converts sunlight into electricity through concentrated solar power or using photovoltaics (PV) (Rani, Ilango, and Nagamani, 2013). The concentrated solar power utilizes mirrors or lenses and tracking systems to concentrate sun rays into a small beam while the photovoltaic cells utilize photovoltaic effect into the production of electric current (Monteiro et al. 2012). To accomplish the production of solar power production, numerous products and services are required. 2.2.

Charge Controller A solar charge controller sometimes called a solar panel regulator is an important component that is integral to the solar charging systems with systems producing more than 10W (Fakham, Lu, and Francois, 2011). The purpose of charge controller is to protect the battery from overcharging. It also protects the panel from problems such as reverse current flow (Lo, Chen, and Chang, 2011). In addition, if the system has a low voltage disconnect facility, the charge controller also protects draining of the battery (Rani, Ilango, and Nagamani, 2013).

It prevents the current from flowing to the solar panel during the night, and also it prevents solar charging kit damage (Yilmaz and Krein, 2013). Different sizes of charge controllers exist which are rated in terms of voltage: 24V, 12V, and 6V targeting solar panels that are rated up to 60A (Rani, Ilango, and Nagamani, 2013). Moreover, there are solar controllers that are designed for dual battery systems, which enables the charge to be used as a starter battery and for leisure. Another important use of charge controller is monitoring the battery voltage (Boico and Lehman, 2012).

The charge controller detects when the battery voltage is low, when the voltage is below certain limits, the charge controller disconnects the system (Kim, Kim, and Kim, 2011). Disconnecting the load from the battery means that the battery is protected from being drained completely (Kassem and Hamad, 2011). It is imperative to note a completely drained battery does not operate in the usual capacities due to the damages to the system (Bhandari et al., 2014). Therefore, the charger controller is targeted towards protecting the battery from fluctuating voltage and overall protection of the solar power system. 2.3.

Charge Controller Types Maximum Power Point Tracking (MPPT) and Pulse Width Modulation (PWM) are the two common types of charging methods, which enables charging of batteries. Even though the names are different, both technologies are appropriate for off-grid solar industry and both options are efficient (Fakham, Lu, and Francois, 2011). The decision to utilize any of the highlighted technologies does not lie on the regulators or which method is better (Rani, Ilango, and Nagamani, 2013). Rather, it involves the determination of the controller that operates effectively with the system design.

To understand the difference between these charge controllers, it is imperative to analyze the PV panel power curve (Messai et al. 2011). The power curve is crucial since it states that expected power generation is achieved through a combination of current (I) and voltage (V) generated by the panel (Hoke and Maksimović, 2013).

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