Presentation on theme: "PowerPoint ® Presentation Photovoltaic Systems Inverters AC Power Inverters Power Conditioning Units Inverter Features and Specifications Arizona Solar."— Presentation transcript:
PowerPoint ® Presentation Photovoltaic Systems Inverters AC Power Inverters Power Conditioning Units Inverter Features and Specifications Arizona Solar Power Society AC Power Inverters Power Conditioning Units Inverter Features and Specifications Arizona Solar Power Society
Chapter 8 Inverters If voltage and current signals are either always positive or always negative, they are DC waveforms. If the signals switch between positive and negative, they are AC waveforms.
Chapter 8 Inverters AC waveforms can take a variety of shapes.
Chapter 8 Inverters Certain parameters are integral to defining the characteristics of an AC waveform.
Chapter 8 Inverters Three-phase power is composed of three separate voltage waveforms that are 120° out of phase.
Chapter 8 Inverters Voltage variations outside allowable ranges include voltage sags, voltage swells, and transients.
Chapter 8 Inverters Three-phase voltage and current waveforms are unbalanced if they are not equal in magnitude.
Chapter 8 Inverters Harmonics can add to the fundamental frequency to produce distorted waveforms.
Chapter 8 Inverters Resistive loads keep the voltage and current waveforms in phase, while reactive loads cause the current waveform to lead or lag the voltage waveform.
Chapter 8 Inverters Inverters are available in many different configurations and ratings.
Chapter 8 Inverters Stand-alone inverters are connected to the battery bank and supply AC power to a distribution panel that is independent of the utility grid.
Chapter 8 Inverters Interactive inverters are connected to the PV array and supply AC power that is synchronized with the utility grid.
Chapter 8 Inverters AC module inverters are small interactive inverters that are supplied by a single PV module.
Chapter 8 Inverters Solid-state switching devices used in PV inverters include transistors and thyristors.
Chapter 8 Inverters Line-commutated inverters use an external AC signal to activate and deactivate the inverter switching devices.
Chapter 8 Inverters H-bridge inverter circuits use two pairs of switching devices to direct a DC input to the output in both directions.
Chapter 8 Inverters Push-pull inverter circuits use one pair of switching devices and a transformer to alternate the direction of direct current.
Chapter 8 Inverters Square waves can be modified by adjusting the duration and magnitude of the pulses.
Chapter 8 Inverters Combining multiple modified square waves with different magnitudes and durations results in a multistepped modified square wave that more closely approximates a sine wave.
Chapter 8 Inverters Pulse-width modulation at high frequencies generates the truest approximation of a sine wave.
Chapter 8 Inverters Power conditioning units are inverters that also perform other power control and conversion functions.
Chapter 8 Inverters Transformers use induced magnetic fields to transfer AC power from one circuit to another while transforming the power to higher or lower voltages or providing electrical isolation.
Chapter 8 Inverters The primary and secondary windings in an autotransformer share some of the same windings.
Chapter 8 Inverters Inverter nameplates include much of the needed information for sizing and operating the inverter.
Chapter 8 Inverters At high temperatures, an interactive inverter may limit current input by raising the input voltage, which also lowers power input and output.
Chapter 8 Inverters Most inverters operate from a relatively wide range of input voltages, but the range for MPPT operation is smaller.
Chapter 8 Inverters In order to output AC voltage within the specified range, the DC input voltage must meet certain minimum values.
Chapter 8 Inverters Inverters may limit maximum DC input current with increasing DC input voltage.
Chapter 8 Inverters Most sine wave inverters maintain high efficiency over a wide operating- power range.
Chapter 8 Inverters Inverter enclosures may include protective devices such as circuit breakers.
Chapter 8 Inverters Inverter interfaces include on-board screens, remote data monitors, and computerized data acquisition and processing software.