Basic knowledge of power inverter
Power inverter mainly adopts the PWM at present, controller switch to DC rapidly in a pulse-period to ensure that the DC integral value is equal to the sampling values of AC sine wave at the same time. After filtered, more than 96% sine wave output can be realized. Pulse inverter is self-excited inverter that output voltage is pulse modulation. This kind of power inverter reduces the voltage and electric current pulse number by increasing the cycle pulse switching times, to realize these only by increasing the commutation count of inverter.
The power inverter inductance of the AC determines the content of current harmonic. Therefore, in order to meet the requirements of grid access, you should guarantee the equivalent inductance value of photo-voltaic power generation system is small. Power inverter is connected to the low-pass filter and isolation transformer. It can filter out the harmonic below N-1, where N is trigger pulses flow of current period. To increase the switching frequency, the power loss of electronic devices will increase, but the loss of low pass filter will increase at low switching frequency. If you want to incorporate current clock multiplier of single-phase AC grid, the AC control signal frequency of Modulation PV generator DC output will double.
Basic Concept of power inverter
Usually, the AC electrical energy transforms into direct current (DC) can be called rectification, the circuit is known as rectifier circuit which completes the function of rectifier, the device achieve rectification process is called a rectifier device or rectifier equipment. Correspondingly, the process that the DC power transforms into AC power is called inverting, the circuit to complete inverter function known as the inverter circuit, the device realize the inverter process is called inverter device or power inverter.
Modern power inverter technology is a science to study inverter circuit theory and application. It is a practical technology based on industrial electronics, semiconductor technology, modern control technology, modern power electronic technology, semiconductor converter technology, pulse width modulation (PWM) technology and other subjects. It mainly includes the semiconductor power integrated device and its application, inverter circuit and the inverter control technology.
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