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Inverter 1 Introduction An inverter is an electrical device that converts direct current (DC) to alternating current (AC)。 the converted AC can be at any required voltage and frequency with the use of appropriate transformers, switching, and control inverters have no moving parts and are used in a wide range of applications, from small switching power supplies in puters, to large electric utility highvoltage direct current applications that transport bulk power. Inverters are monly used to supply AC power from DC sources such as solar panels or batteries. There are two main types of inverter. The output of a modified sine wave inverter is similar to a square wave output except that the output goes to zero volts for a time before switching positive or negative. It is simple and low cost and is patible with most electronic devices, except for sensitive or specialized equipment, for example certain laser printers. A pure sine wave inverter produces a nearly perfect sine wave output (3% total harmonic distortion) that is essentially the same as utilitysupplied grid power. Thus it is patible with all AC electronic devices. This is the type used in gridtie inverters. Its design is more plex, and costs 5 or 10 times more per unit power The electrical inverter is a highpower electronic oscillator. It is so named because early mechanical AC to DC converters were made to work in reverse, and thus were inverted, to convert DC to inverter performs the opposite function of a rectifier. 2 Applications DC power source utilization An inverter converts the DC electricity from sources such as batteries, solar panels, or fuel cells to AC electricity. The electricity can be at any required voltage。 in particular it can operate AC equipment designed for mains operation, or rectified to produce DC at any desired voltageGrid tie inverters can feed energy back into the distribution work because they produce alternating current with the same wave shape and frequency as supplied by the distribution system. They can also switch off automatically in the event of a 1 convert direct current from individual solar panels into alternating current for the electric grid. They are grid tie designs by default. Uninterruptible power supplies An uninterruptible power supply (UPS) uses batteries and an inverter to supply AC power when main power is not available. When main power is restored, a rectifier supplies DC power to recharge the batteries. Induction heating Inverters convert low frequency main AC power to a higher frequency for use in induction heating. To do this, AC power is first rectified to provide DC power. The inverter then changes the DC power to high frequency AC power. HVDC power transmission With HVDC power transmission, AC power is rectified and high voltage DC power is transmitted to another location. At the receiving location, an inverter in a static inverter plant converts the power back to AC. Variablefrequency drives A variablefrequency drive controls the operating speed of an AC motor by controlling the frequency and voltage of the power supplied to the motor. An inverter provides the controlled power. In most cases, the variablefrequency drive includes a rectifier so that DC pow