INVERTERS - How much power for conversion

[mtnelect]

How much power is consumed to convert D.C. to A.C. ? I understand that power conversion waste energy, but how much.

 

[Besoeker3]

How much power is consumed to convert D.C. to A.C. ? I understand that power conversion waste energy, but how much.

I have used a lot of calculations on VSDs. We typically used 95% efficiency calcs mostly for water pumping stations.

 

[electrofelon]

How much power is consumed to convert D.C. to A.C. ? I understand that power conversion waste energy, but how much.

They are very efficient. Most PV Inverters are at least 96.5% efficient. Many are in the 98's.

 

[mtnelect]

Is there an independent testing authority like UL that rates inverters and not just the manufacturer ?

 

[jaggedben]

Yes. Your favorite. The California Energy Commission.

 

[AlbertL57]

The data sheet for the inverter will show the efficiency. Of course, there are other sources of energy loss in addition to inverter efficiency, such as wiring resistance.

 

[winnie]

When looking at the data sheet, remember that the stated efficiency number is at a particular operating point, and will change with load and temperature

 

[mtnelect]

When looking at the data sheet, remember that the stated efficiency number is at a particular operating point, and will change with load and temperature

I agree ... It's like when I do a "Heat Load" engineering study for a HVAC system. For example, the total Heat Load is 24,000 btu, then you have to look at the engineering data for that particular brand unit and select the system that meets your requirements. There are two data points "Sensible Heat" and "Latent Heat". In California because we have low humidity we disregard the latent heat amount.

 

[electrofelon]

When looking at the data sheet, remember that the stated efficiency number is at a particular operating point, and will change with load and temperature

True, but not very much. Sandia laboratories says: "Typical grid-tied inverter efficiencies exceed 95% under most operating conditions."

CEC Inverter Test Protocol

Inverter efficiency is the ratio of the usable AC output power to the sum of the DC input power and any AC input power. Typical grid-tied inverter efficiencies exceed 95% under most operating conditions Efficiency changes as a function of AC output power, DC voltage, and sometimes inverter temper...

pvpmc.sandia.gov

 

[PWDickerson]

I believe CEC uses a weighted efficiency over a broad range of power conversion levels, and it is shown on most inverter data sheets.