Solar and Battery Powered Drives

Solar and Battery Powered Drives:

Battery Powered Vehicles : Battery Powered Vehicles – These are popularly known as electric vehicles. Although several batteries and fuel cells have been developed, only available at affordable price is the lead acid battery. Therefore, electric vehicles are generally powered by lead acid batteries. Series and separately excited dc motors, permanent magnet dc motor, brushless dc motor and induction motor have been used in electric vehicles. The advantages of electric vehicles (EV) over the internal combustion vehicles (ICV) are: Less pollution. Quieter operation. Less maintenance: The electric drive being simple requires hardly any maintenance. Unlike ICV, EV has no water cooling system to maintain, no filters, belts, or hoses to replace, or no oil to change. More reliable: Due to the presence of fuel injectors, compressors, pumps and valves, water cooling system, filters, an internal combustion engine is lot more complex compared to an electric drive, and therefore, less reliable. The disadvantage are: More expensive. EV cannot go nearly as …


Solar Panels or Photovoltaic Cells : A Solar Panels or Photovoltaic Cells converts sunlight into electricity. Single crystal, polycrystal and amorphous silicon cells have been employed. The open circuit voltage is about 0.5 V for mono-and polycrystal solar cells and 0.8 V for amorphous cells. Each cell can carry a current between 2 and 3 A. By connecting solar cells in a suitable series and parallel combination, required voltage and current ratings are obtained. The mounting of solar cells in series and parallel combination is known as Solar Panel or Solar Array. Each parallel branch is provided with a diode in order to avoid circulating currents. When a panel consisting of cells in series is used to charge a battery, a diode is connected so that current never flows from the battery to the solar cells. The output of a Solar Panels or Photovoltaic Cells depends on the insolation level (brightness of the sunlight) …


Solar Powered Pump Drives : Solar Powered Pump Drives: Centrifugal and reciprocating. Their speed-torque characteristics are shown in Fig. 9.3. Centrifugal pump requires only a small torque to start whereas reciprocating pump owing to stiction may require as much as three times the rated torque. In centrifugal pump the output power is proportional to the cube of speed, and therefore, drastically reduces as the speed is reduced; for example, the output power reduces to half at a speed of 80%. In reciprocating pump, since with a reduction in speed the torque reduces only by a small amount, the percentage reduction in output is slightly more than the percentage reduction in speed. A simple scheme of Solar Powered Pump Drives using a permanent magnet dc motor is shown in Fig. 9.4. The solar panel directly feeds the motor. One can connect the solar cells to form a low-voltage-high-current or low-current-high-voltage unit. A low current-high-voltage …