Pure Sine Wave Inverter vs. Ordinary Inverter
Pure sine wave inverters have strict requirements for function and parameters. It is more expensive and can be used in electronic circuits that require higher waveform parameters. The ordinary inverter is a hybrid waveform of a sine wave, square wave, clutter and other components, which can be used for general electrical appliances, and the price is low.
In this article, we will introduce the differences between pure sine wave inverter in ATO.com and ordinary inverter.
Sine wave inverter input circuit
The input of the inverter is usually direct current or direct current obtained by rectifying and filtering the mains. These direct currents include direct currents from the DC grid, batteries, photovoltaic cells and other methods. Usually, this electrical energy cannot be directly used as the voltage on the input side of the inverter. It is used as the input of the inverter after passing through a certain filter circuit and EMC circuit.
Inverter main circuit
The main circuit of the inverter is a power conversion circuit composed of power switching devices. The structure of the main circuit is divided into many types. Under different input and output conditions, the main circuit forms are also different. Each power conversion circuit has its own advantages and disadvantages. In the actual design, the most suitable circuit topology should be considered as the main circuit structure.
Protection circuit
Protection circuits of pure sine wave inverters usually include input overvoltage, under-voltage protection, output overvoltage, under-voltage protection, overload protection, and overcurrent and short circuit protection. There are other protections for inverters working on specific occasions, such as temperature protection on very low or very high-temperature occasions, air pressure protection in the case of certain air pressure changes, and air pressure protection in humid environments. Humidity protection, etc.
Control circuit
According to the requirements of the inverter output, the control circuit generates one or more sets of pulse voltages through a certain control technology. The drive circuit acts on the power switch tube to turn on or off the power switch tube in the specified order and finally outputs the main circuit. terminal to obtain the desired voltage waveform. The function of the control circuit is very important for the inverter system, and the performance of the control circuit directly determines the quality of the output voltage waveform of the inverter.
Output circuit
The output circuit generally includes an output filter circuit and an EMC circuit. If the output is direct current, a rectifier circuit should be added later. For an inverter with isolated output, an isolation transformer should also be provided at the front stage of the output circuit. According to whether the output needs a voltage regulator circuit, the output circuit can be divided into open-loop and closed-loop control. The output of the open-loop system is only determined by the control circuit, while the output of the closed-loop system is also affected by the feedback loop, making the output more stable.
Auxiliary power supply
Some parts or chips of the control circuit and the input and output circuit have specific input voltage requirements, and the auxiliary power supply can meet the specific voltage requirements in the circuit. Usually, the auxiliary power supply consists of one or several DC-DC converters. For the case of AC input, the auxiliary power supply is completed by the combination of the rectified voltage and the DC-DC converter.
