光伏专业英文词汇

Glossary第 页 共 19 页 1Activated shelf life The time it takes for the capacity of a charged battery to fall to an unusable level when stored at a specified temperature. Activation voltage The voltage at which the controller will operate to protect the batteries. AGM Adsorbed Glass Mat a newer type of battery construction that uses saturated adsorbant glass mats rather than gelled or liquid electrolyte. AGM batteries are typically more expensive than flooded liquid, but offer enhanced reliability. Air mass The air mass relates to the path length of solar radiation through the atmosphere. An air mass of 1.0 means the sun is directly overhead and the radiation travels through one atmosphere thickness. Approximately equal to the secant of the zenith angle, i.e. the angle from directly overhead to a line to the sun. Alternating current AC Electrical current that continually reverses direction of flow. The frequency at which it reverses is measured in cycles-per-second, or Hertz Hz. The magnitude of the current itself is measured in amps A. Alternator A device for producing Alternating Current “AC“ electricity. Usually driven by a motor, but can also be driven by other means, including water and wind power. Ambient temperature The temperature of the surroundings. Ammeter A device used for measuring current flow at any point in an electrical circuit. Amorphous silicon A thin-film solar PV cell material which has a glassy rather than crystalline structure. Made by depositing layers of doped silicon on a substrate normally using plasma-enhanced chemical vapor deposition of silane. Amp hour The quantity of electrical energy corresponding to the flow of current of one ampere for one hour. The term is used to quantify the energy stored in a battery. Most batteries are rated in Ah. Ampere A or amp The unit for the electric current; the flow of electrons. One amp is 1 coulomb passing in one second. One amp is produced by an electric force of 1 volt acting across a resistance of 1 ohm. Anemometer A device used to measure wind speed. Angle of incidence Angle between the normal to a surface and the direction of incident radiation; applies to the aperture plane of a solar panel. Only minor reductions in power output within plus/minus 15 degrees. Anode The positive electrode in a battery. The positive terminal of a diode. Anti-reflection coating A thin coating of a material with a specific refractive index applied to a cell to reduce the reflection of light. Array A number of solar modules connected together in a single structure.Array current The electrical current output of a PV array when exposed to sunlight. Array operating voltage The voltage output of a PV array when exposed to sunlight and feeding a load. Autonomous system A PV System that operates without any other energy generating source. Availability The quality or condition of a PV system that is available to provide power to a load. Usually measured in hours per year. 2AWG American Wire Gauge a standard system for designating the size of electrical wire. The higher the number, the smaller the wire. Most house wiring is 12 or 14. Azimuth The Angle between the north direction and the projection of the surface normal into the horizontal plane; measured clockwise from north. As applied to the PV array, 180 degree azimuth means the array faces due south.Balance of system BOS All the parts of a PV System excluding the solar module Ballast a circuit used to stabilize an electric current, for example, in a fluorescent light. Battery A system in which stored chemical energy is converted directly into electrical energy. Can be either rechargeable or non-rechargeable. Different to a fuel cell in that it contains a fixed quantity of stored chemical energy rather than a continuous supply of fuel. Battery capacity The total number of ampere-hours Ah that a fully charged battery can output. Battery cell An individual unit of a battery that can store electrical energy and is capable of furnishing a current to an external load. For lead-acid batteries the voltage of a cell fully charged is about 2.2 volts dc. A battery may consist of a number of cells. Battery charger A device used to charge a battery by converting usually mains voltage AC to a DC voltage suitable for the battery. Chargers often incorporate some form of regulator to prevent overcharging and damage to the battery. Battery cycle Life The number of times a battery can undergo a cycle of discharge and recharge before failing. Cycle Life is normally specified as a function of discharge rate and temperature. Battery self-discharge Energy loss by a battery that is not under load. Battery state of charge SOC Extent of battery charge status as a percentage of full charge. Also 100 per cent minus the Depth of Discharge. BIPV Building Integrated Photovoltaics. As the name suggests, this is where PV modules are integrated in to the building construction materials as on integrated unit.Blocking diode A diode used to prevent current flow in an undesirable direction e.g. from the rest of the PV array to a failed module or from the battery to the PV array when current generation is low.British Thermal Unit BTU The amount of heat energy required to raise one pound of water from a temperature of 60 degrees F to 61 degrees F at one atmosphere pressure. One Watt hour equals 3,413 BTU. Bypass diode A diode connected across one or more solar cells in a photovoltaic module such that the diode will conduct if the cells become reverse biased. [UL 1703]Capacitor An electronic component used for the temporary storage of electricity, as well for removing unwanted noise in circuits. A capacitor will block Direct Current but will pass Alternating Current. Capacity See Battery Capacity. Captive electrolyte battery A battery with an immobilized electrolyte gelled or Glossary第 页 共 19 页 3absorbed in a material. Cathode The negative electrode in an electrochemical cell. Also, the negative terminal of a diode. Cathodic protection A method of preventing oxidation rusting of exposed metal structures, such as bridges and pipelines, by imposing between the structure and the ground a small electrical voltage that opposes the flow of electrons and that is greater than the voltage present during oxidation. Cell efficiency The ratio of the electrical energy produced by a photovoltaic cell under full sun conditions or 1 kW/m2 to the energy from sunlight falling upon the photovoltaic cell. Cell junction The area of immediate contact between two layers positive and negative of a photovoltaic cell. The junction lies at the center of the cell barrier or depletion zone. Cell The basic unit of a PV module or battery. The most basic unit that contains the necessary materials, such as electrodes and electrolyte in a battery, to produce electricity. Charge The process of inputting electrical energy to a battery. Charge controller A component that controls the flow of current to and from the battery subsystem to protect the batteries from overcharge and over discharge. Essential for ensuring that batteries obtain maximum state of charge and longest life. The charge controller may also monitor system performance and provide system protection. Charge Controllers are also sometimes called Regulators. Charge factor A number corresponding to the time in hours for which a battery can be charged at a constant current without damaging it. Usually expressed as a function of battery capacity, e.g. C/10 indicates a charge factor of 10 hours. Related to Charge Rate. Charge rate A measure of the current used to charge a battery as a proportion of its capacity. Circuit A continuous system of conductors providing a path for electricityCircuit breaker A circuit breaker acts like an automatic switch that can shut the power off when it senses too much current. Cloud enhancement The increase in solar intensity due to reflected light from nearby clouds. Cogeneration The joint production of electricity and useful heat at a single facility, resulting in more efficient use of the thermal energy. Concentrator A photovoltaic device that uses optical elements e.g. mirrors or lenses to increase the amount of light incident on a solar PV cell. Concentrator arrays track the sun and use only direct sunlight since the diffuse portion cannot be focused. Concentrators therefore work best in clear sky locations. Efficiency is increased, but cell life may be reduced because operating temperatures are higher.Conductor A material used to transfer, or conduct, electricity, often in the form of wires. Conduit A pipe or elongated box used to house and protect electrical cables. Conversion efficiency The ratio of the electrical energy generated by a solar PV cell 4to the solar energy impacting the cell. Cross-flow turbine A turbine where the flow of water is at right angles to the axis of rotation of the turbine. Crystalline silicon A type of PV cell material made from a single crystal or polycrystalline ingot of silicon. Current Current is the flow of electric charge in a conductor between two points having a difference in electrical potential voltage and is measured in Amps. Current at maximum power Imp The current at which maximum power is available from a module. [UL 1703] Cut-off voltage The voltage levels at which the charge controller regulator disconnects the PV array from the battery, or the load from the battery. Cycle The discharge and re-charge of a battery, one complete charge/discharge cycle of the battery. Cycle life Number of charge-discharge cycles a battery can perform under specified conditions before it fails to meet its specified performance e.g. capacity decreases to 80 of nominal capacity.Days of storage The number of days that a stand-alone system will power a specified load without solar energy input. A measure of system autonomy. DC to DC converter Electronic circuit to convert dc voltages e.g., PV module voltage into other levels e.g., load voltage. Can be part of a maximum power point tracker MPPT. Dealer A Retailer of PV products and/or PV SystemsDeep cycle battery A battery designed to regularly discharge 80 of its capacity before recharging. Deep discharge Discharging a battery by more than 80 of its full charge.Depth of discharge DOD the amount of energy withdrawn from a battery or cell expressed as a percentage of its rated capacity. Design month The month in which the combination of insolation and load requires the maximum energy from the array. Diffuse insolation Incident sunlight received indirectly because of scattering due to clouds, fog, particulates, or other obstructions in the atmosphere. The other component of sunlight is Direct. Diffuse radiation Radiation received from the sun after reflection and scattering by the clouds, fog, haze, dust or other substances in the atmosphere, and the ground. Diode Electronic device that allows current flow only in one direction. Direct beam radiation Radiation received by direct sunlight. Measured by a pyrheliometer with a solar aperture of 5.7 to transcribe the solar disc. Direct current DC Electrical current that flows only in one direction, although it may vary in magnitude. Contrasts with alternating current.Direct insolation Sunlight falling directly upon a collector. Opposite of diffuse insolation. Direct radiation Light that has traveled in a straight path from the sun also referred to as beam radiation. An object in the path of direct radiation casts a shadow on a clear day. Discharge Withdrawal of electrical energy from a battery. Glossary第 页 共 19 页 5Discharge factor A number equivalent to the time in hours during which a battery is discharged at constant current usually expressed as a percentage of the total battery capacity, i.e., C/5 indicates a discharge factor of 5 hours. Discharge rate A measure of the current withdrawn from a battery over time, expressed as a percentage of battery capacity. A C/5 discharge rate indicates a current of one-fifth of the rated capacity of the battery. Disconnect Switch used to connect or disconnect components in a PV system.Dispatchability The ability of a generating unit or other source of electric power to vary output. Dispatchable power Energy output that can be planned on and typically provides a continuous power output. Solar power and Wind power in not dispatchable without configuration with out some other power or storage mechanism. Hydrocarbon based power plants or nuclear plants are dispatchable. Distributed systems Systems that are installed at or near the location where the electricity is used, as opposed to central systems that supply electricity to grids. A residential photovoltaic system is a distributed system. Distributor Using means a wholesaler of PV productsDowntime Time when the PV system cannot provide power to the load, expressed either in hours per year or as a percentage. Dry cell battery A battery that uses a solid paste for an electrolyte. Duty cycle The ratio of active to total time, used to describe the operating regime of loads in PV systems. Duty rating The amount of time an inverter can operate at full rated power. Some inverters can operate at their rated power for only a short time without overheating.Earth Refers to physically connecting a part of an electrical system to the ground, done as a safety measure, by means of a conductor embedded in suitable soil. Earth-leakage circuit breaker ELCB A device used to prevent electrical shock hazards in mains voltage power systems, including independent power systems. Also known as residual current devices RCDs. Efficiency The ratio of output power or energy to input power or energy, expressed as a percentage. Electric circuit Path followed by electrons from a power source generator or battery through an external line including devices that use the electricity and returning through another line to the source. Electric current The flow of electrons measured in Amps. Electrical grid A network for electricity distribution across a large area.Electricity The movement of electrons a sub-atomic particle, produced by a voltage, through a conductor. Electrode An electrically conductive material, forming part of an electrical device, often used to lead current into or out of a liquid or gas. In a battery, the electrodes are also known as plates. Electrolysis A chemical reaction caused by the passage of electricity from on electrode to another. Electrolyte The medium that provides ionic transport between the electrodes of a 6battery. All common batteries contain an electrolyte, such as the sulfuric acid used in lead-acid batteries. Energy density The ratio of the energy available from an energy storage device such as a battery to its volume Wh/m3 or weight Wh/kg. Energy payback time The time required for any energy producing system or