Solar Inverter Systems

Solar inverters function to change direct current (DC) from a battery to Alternating Current (AC). Stand alone inverters, which range from around 100 watts to as much as 8000 watts, are used to power a vast variety of personal or small business projects. Lower watt stand-alone inverters are often used to power laptop computers, whereas high-watt stand-alone inverters could be used to help power an entire household.

The heart of the inverter is a real-time microcontroller. The controller executes the very precise algorithms required to invert the DC voltage generated by the solar module into AC. This controller is programmed to perform the control loops necessary for all the power management functions necessary including DC/DC and DC/AC. The controller also maximizes the power output from the Photovoltaic (PV) through complex algorithms called maximum power point tracking (MPPT). The PV maximum output power is dependent on the operating conditions and varies from moment to moment due to temperature, shading, soilage, cloud cover, and time of day so tracking and adjusting for this maximum power point is a continuous process. For systems with battery energy storage, the controller can control the charging as well as switch over to battery power once the sun sets or cloud cover reduces the PV output power. The controller contains advanced peripherals like high precision PWM outputs and ADCs for implementing control loops. The ADC measures variables, such as the PV output voltage and current, and then adjusts the DC/DC or DC/AC converter by changing the PWM duty cycle.