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Learn all about PV Inverter
| An inverter is an electronic device that converts direct current (DC) to alternating current (AC). PV modules (also called PV panels) convert sunlight into DC electricity. A solar inverter, or photovoltaic (PV) inverter, is connected to an array of PV modules and converts the DC electricity produced by the solar modules into grid-compliant AC electricity. The AC electricity can then be used in three ways: 1. Stand-alone inverters - also called off-grid inverter, this inverter draws its DC energy from photovoltaic arrays, and the AC output is used to operate electrical devices within the system. Normally, these inverters do not interface with the utility grid. Many stand-alone inverters also incorporate integral battery chargers to replenish a battery, so that electricity can be used even when the sun is down and the PV modules do not produce electricity. These would normally operate a charge controller which regulates the input from the PV inverter and the batteries, regulates the battery output, and handles the battery charging. 2. Grid-tie inverters - the inverter supplies the AC electricity to the utility grid. The inverter's input will match phase with the utility-supplied sine wave. Grid-tie inverters are designed to automatically disconnect and shut down when there is loss of utility supply. This is done to ensure that utility workers or fire fighters, who disconnect the grid, are not hurt by the electricity fed into the grid by the inverter. These inverters do not provide backup power during power outages. 3. Battery backup inverters - these inverters are a combination of the first two types. They provide the electricity needs of the system they are connected to, and export excess energy to the utility grid. These inverters also are capable of supplying AC energy selectively during blackouts. Traditionally inverters perform Maximum Power Point Tracking to optimize power generation from the whole PV array. PV cells have a single operating point where the values of the current (I) and Voltage (V) of the cell result in a maximum power output. Maximum power point tracking utilizes some type of control circuit or logic to search for this point and thus to allow the converter circuit to extract the maximum power available from the PV array. A new approach of distributed architecture, in which MPPT is done in a panel level, is recently gaining popularity, influencing the design of new generation of inverters. In this architecture an MPP tracker is connected to each PV panel and tracks its individual maximum power point, independently of other panels. The inverter then, is only responsible for DC-AC conversion, which makes it more efficient and reliable than traditional inverters. The panel-level MPP tracker may also act as an inverter, or more precisely - micro-inverter, performing both the MPPT and DC-AC conversion at the panel level. |
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SolarEdge provides Distributed Solar Power Harvesting and Solar Monitoring Software for maximum energy production at lower cost. Solution includes module-level power optimizers and monitoring and a multi-string PV inverter for constraint-free design and safety installation and maintenance of PV systems.
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