A sine wave inverter is a type of inverter that converts direct current (DC) energy (from power batteries or storage batteries) into alternating current (AC) (typically 220V, 50Hz sine wave). The process of an inverter is the opposite of that of an AC-DC converter. Since AC-DC converters or power adapters rectify 220V AC power into DC power for use, and inverters perform the opposite function, they are named as such.
A sinusoidal inverter is an electrical energy conversion device that converts direct current (DC) to alternating current (AC). It accomplishes the inversion task by switching power semiconductor devices on and off according to specific rules. Modern inverter technology is a science that studies the theory, application, and design methods of inverter circuits. It is a practical technology built on the scientific foundations of industrial electronics, semiconductor device technology, modern control technology, modern power electronics technology, pulse width modulation technology, semiconductor converter technology, and magnetic materials. Therefore, the application of sinusoidal inverters spans many areas of society and life.
The principle of a sine wave inverter is as follows:
An inverter converts direct current (DC) to alternating current (AC). It consists of an inverter bridge, an SPWM (Signal Width Modulation) wave module, a drive module, and a filter circuit. The SPWM inverter circuit is crucial for generating a pure sine wave. SPWM wave generation has been a hot research topic. SPWM, or Pulse Width Modulation, is a pulse waveform with a variable duty cycle. PWM control technology is based on this theory. By controlling the on/off state of semiconductor switching devices, a series of pulses with equal amplitude but unequal width are obtained at the output to equivalently acquire the desired waveform. When performing pulse width modulation, if the duty cycle of the pulse series is arranged according to a sinusoidal pattern, the output voltage, after filtering, can obtain a sinusoidal waveform. Simultaneously, the harmonic components in the load current are greatly reduced; this is called sinusoidal pulse width modulation.
The functions of a sine wave inverter include:
Inverter output function: After turning on the "Inverter Switch (IVT SWITCH)" on the front panel, the inverter will convert the DC power of the battery into pure sine wave AC power, which will be output through the "AC Output (AC OUTPUT)" on the rear panel.
Automatic voltage regulation function: When the battery pack voltage fluctuates between the undervoltage and overvoltage points, and the load varies within the rated power range, the equipment can automatically regulate the output voltage. Overvoltage protection function: When the battery voltage exceeds the "overvoltage point," the equipment will automatically cut off the inverter output, display "Overvoltage" on the front panel LCD, and simultaneously sound a ten-second alarm. The inverter will resume operation once the voltage drops to the "overvoltage recovery point."
Undervoltage protection function: When the battery voltage is lower than the "undervoltage point," the device will automatically cut off the inverter output to prevent damage to the battery from over-discharge. At this time, the front panel LCD will display "Undervoltage," and the buzzer will sound an alarm for ten seconds. The inverter will resume operation when the voltage rises to the "undervoltage recovery point"; if a switching device is selected, it will automatically switch to AC power output during undervoltage.
Overload protection function: If the AC output power exceeds the rated power, the device will automatically cut off the inverter output, the front panel LCD will display "Overload", and a buzzer will sound an alarm for ten seconds. Turning off the "Inverter Switch (IVT SWITCH)" on the front panel will remove the "Overload" display. To restart, you must check and confirm that the load is within the allowable range before turning the "Inverter Switch (IVT SWITCH)" back on to restore the inverter output.
Short-circuit protection function: If a short circuit occurs in the AC output circuit, the device will automatically cut off the inverter output, the front panel LCD will display "Overload," and a buzzer will sound an alarm for ten seconds. Turning off the "Inverter Switch (IVT SWITCH)" on the front panel will remove the "Overload" display. To restart, you must check and confirm that the output circuit is normal before turning the "Inverter Switch (IVT SWITCH)" back on to restore the inverter output.
Battery reverse connection protection: The equipment has a comprehensive battery reverse connection protection function. If the battery's positive and negative terminals are reversed, the fuse in the chassis will automatically blow to prevent damage to the battery and equipment. However, reverse connection of the battery is still strictly prohibited!
