# Ch 8 PV

 Direct Current Electrical current that flows in one direction, either positive or negative Alternating Current Electrical current that changes between positive and negative directions Frequency The number of waveform cycles in one second Period The time it takes a periodic waveform to complete one full cycle before it repeats Peake The maximum absolute value of a waveform Peake-to-peake A measure of the difference between positive and negative maximum values of a waveform Root-Mean-Square (RMS) Value A statistical parameter representing the ffective value of a waveform Voltage Unbalance The unbalance that occurs when the voltages of a three-phase power supply or the terminals of a three-phase load are not equal Single Phasing The complete loss of one phase on a three-phase power supply Current Unbalance The unbalance that occurs when current is not equal on the three power lines of a three-phase system Phase Unbalance The unbalance that occurs when three-phase power lines are more or less that 120 degrees out of phase Harmonic A waveform component at an integer multiple of the fundamental waveform frequency Total Harmonic Distortion (THD) The ratio of the sum of all harmonic components in a waveform to the fundamental frequency component Resistive Load A load that keeps voltage and current waveforms in phase True Power Is the product of in-phase voltage and current waveforms and produces useful work Reactive Load An AC load with inductive and/or capacitive elements that cause the current and voltage waveforms to become out of phase Reactive Power The product of out-of-phase voltage and current waveforms and results in no net power flow Power Factor The ratio of true power to apparent power and describes the displacement of voltage and current waveforms in AC circuits Apparent Power A combination of true and reactive power and is given in units of volt-amperes (VA) Inverter A device that converts DC power to AC power Line-Commutated Inverter An inverter whose switching devices are triggered by and external source Self-Commutated Inverter An inverter that can internally control the activation and duration of its switching Rectifier A device that converts AC power to DC power Transformer A device that transfers energy from one circuit to another through magnetic coupling DC-DC converter A device that changes DC power from one voltage to another Maximum Power Point Tracker (MPPT) A device or circuit that uses electronics to continually adjust the load on a PV device under changing temperature and irradiance conditions to keep it operating at its maximum power point Inverter Efficiency Is the effectiveness of an inverter at converting DC power to AC power Authorcgore ID163070 Card SetCh 8 PV DescriptionCh 8 PV Updated2012-07-19T07:07:00Z Show Answers