At present, PWM is mainly used in power inverter , and the controller switches to DC quickly in a pulse period to ensure that the DC integral value equals the sampling value of AC sinusoidal wave at the same time. After filtering, more than 96% sinusoidal output can be achieved. Pulse inverters are self-excited inverters, and the output voltage is pulse modulation. This power inverter reduces the number of voltage and current pulses by increasing the number of cycle pulse switching, which is achieved only by increasing the number of commutation times of the inverter.
The inductance of AC power inverter determines the current harmonic content. Therefore, in order to meet the requirements of grid access, the equivalent inductance of photovoltaic power generation system should be small. Power inverters are connected to low-pass filters and isolation transformers. It can filter the harmonics below N-1, where N is the trigger pulse current of the current cycle. In order to increase the switching frequency, the power loss of electronic devices will increase, but the loss of low-pass filters with low switching frequency will increase. If combined with the current clock frequency multiplier of single-phase AC network, the frequency of AC control signal that modulates the DC output of photovoltaic generator will be doubled.
Usually, converting AC energy into DC energy can be called rectifier. This circuit is called rectifier circuit. It completes the function of rectifier. The rectifier process of this device is called rectifier device or rectifier device. Correspondingly, the process of converting direct current to alternating current is called inverting phase, and the circuit that completes the inverting circuit is called inverting circuit. The inverting process of this device is called inverting device or inverting power supply.
Modern inverting power supply technology is a subject to study the theory and application of inverting circuit. It is a practical technology based on industrial electronics, semiconductor technology, modern control technology, modern power inverter electronics technology, semiconductor converter technology, pulse width modulation (PWM) technology and other topics. It mainly includes semiconductor power integrated devices and their applications, inverters and inverters control technology.
POWER INVERTER 