The most important step in solar power generation is the conversion of DC to AC, a process that is generated by the solar inverter. How does the inverter, known as the brain of the solar system, process DC to AC? This article will answer your questions
1. Principle of DC to AC conversion
Before calculating the conversion of DC to AC, we first understand the principle of conversion, the inverter through the H-bridge, containing 4 switches will be DC through the circuit and regularly open and close the 4 switches to change the direction of the current can be formed AC, this time the need for AC peaks between the smooth transition between the excesses of the transformation into a pure sinusoidal waveform, so the size and direction of AC power are changing, the size of the direction of the DC power are unchanged. Now in you will be able to easily know the DC current size and voltage are expressed in the specific size, the AC current size and voltage only indicates the peak size.
2. Conversion of DC to AC
In practice, DC power converted to AC power by the inverter due to resistance losses, the conversion efficiency of the inverter in about 90%, the calculation of DC to AC conversion, leaving aside the resistance losses
(1) AC without boosting and bucking
Because DC and AC power represent current and voltage in different ways so it is not directly both current and voltage are not the same. Existence
Equivalent voltage is Vp/√2, DC voltage is Vp × 0.636, where Vp is the peak voltage, the current exists equivalent current is Ip/√2, DC current is Ip × 0.636
(2) Alternating current that has been boosted and bucked
For the AC power has been boosted and bucked can not directly discuss the relationship between the current voltage and DC voltage, the need for other physical quantities of power (P) unit w, joule (w) is the unit of energy does not take into account the conversion of DC to AC losses when the same as the energy of the current watts will not change, we can not directly get watts, but can be converted to
P (W) = I (A) × U (V), W (J) = P (W) × t (s)
Calculations generally take the same amount of time, indirectly through the power of the comparison
Direct current: P (W) = I (A) × U (V), alternating current: P (W) = (I (A) × U (V))/2
Theoretically AC power = DC power.
3. Calculation of loss of DC to AC conversion of solar inverter
We are clear about the flow of DC power into the inverter before and out of the inverter after the calculation of AC power can be simple calculation of the inverter conversion loss, first of all, we have to use a multimeter to measure the flow of current into the solar inverter DC (I) voltage DC (U) and out of the solar inverter current AC (I) voltage AC (U)
Utilize P (W) = I (A) x U (V)
Calculate the DC power DC (P) and AC power AC (P)/2, the efficiency is DC (P)/AC (P)/2 × 100
The efficiency of a normal solar inverter is above 90% if the efficiency is too low, it means that the inverter is of poor quality or damaged.
According to the loss rate of the inverter can simply calculate the AC power
For example, if a 300w solar panel is at its peak when the inverter loss is 5%, then the AC power is 300w x 95% = 285w.
Conclusion:
Understanding DC to AC conversion calculations can be a simple way of estimating the size of solar power needed when traveling in a caravan or installing solar panels at home, and you can always check that your inverter is running efficiently, and DC to AC conversion is very important in a solar system.
