Power Inverters Knowledge

Wellsee Charge-Controlling Inverter

Written by Wellsee Solar Wednesday, 02 December 2009 11:13

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WELLSEE Charge-Controlling Inverter is designed with a controlling system for the storage battery’ s charge and discharge, which can effectively protect the service life of storage batteries. It is an integration of a charger and an inverter, and an extra Solar Charge Controller is not necessary.

What is the efficiency of an inverter?

An inverter itself consumes some electric power at work; therefore, its input power is greater than output power. The efficiency of an inverter is the power ratio of input to output. For example, if an inverter is input 100W DC and outputs 90W AC, then, its efficiency is 90%.

What is the sustained output power? What is the peak output power?

Some electrical appliances or tools which employ electric motors, such as refrigerators, washing machines, electric drills etc. need to take great strong electric current to drive at the moment they get started. However, once they have gotten stated successfully, only a little electric current is needed to maintain their normal working. Therefore, there is the concept of sustained power output and peak output power for the inverter. The sustained power output is rated output power. Generally, the peak output power is twice as much as the rated output power. It must be emphasized that some electrical appliances, such as air conditioners, refrigerators etc. can take 3-7 times as much electric current when getting started as they need in normal working. Therefore, only the inverter which can meet the starting peak power can work normally.

How to choose an inverter?

The following matters should be made clear before choosing to buy an inverter: Make sure the voltage of DC input, volume of load and type of load. A normal inverter has only one stall of DC input voltage, and the users need to select the inverter corresponding to the specification of DC power; the volume and type of load are the items on which the users should focus when choosing to buy an inverter. As the largest output power of an inverter is fixed, the starting power of a load with a compressor is several times as much as its rated power, so the users should choose an inverter with larger output power for it.

How to determine the storage battery's capacity based on electrical appliances?

It should be the lead-acid storage battery that can charge and discharge power in deep cycles to support an inverter. For the storage battery with deep-discharging function, the general unit of measurement for capacity is ampere-hour (AH) which indicates the quantity of current that the storage battery can supply in a unit of time (usually 20 hours). For example, a storage battery with a quantity of electricity of 100AH indicates that it can supply 5 amperes electricity within uninterrupted 20 hours, that is 20×5 = 100.

The storage battery is a very important component in an inverter system. The users should choose the battery of good quality and great capacity when choosing to buy storage batteries. The storage battery of great capacity can be used for a long time; meanwhile, it can provide sufficient electrical current for the instant starting of some high-power electrical appliances. For those high-power electrical appliances, it is suggested that the storage battery should be of 200AH (<1000W), and if the power is even higher, the battery of 400AH should be the best.