Also the grid tie power inverter as they are known can alter the phase angle and the polarity as soon as they cross 0 volts. The inverters can predict the flow of current in an appliance and the voltage automatically rises or falls. Thus the appliance can work at its optimum power and won’t prove to be a problem if the voltage goes up or down and even if the appliance needs different amount of voltage.
If you are looking for a pure sine wave inverter then the best place to search is the internet as a lot of sellers are providing inverters of all sizes and powers. You can check out the collection of inverters out there and then make your choice. But don’t forget to check every tiny detail before buying that inverter.