In Swedish the meaning of the name Lovisa is: Renowned battle maid.
http://www.sheknows.com/baby-names/name/lovisa 
In Swedish the meaning of the name Helena is: Light.
In English the meaning of the name Helena is: In mythology the abduction of Zeus's mortal daughter Helen sparked the Trojan War. 
http://www.sheknows.com/baby-names/name/helena

I was baptised Lena Maria but for various reasons changed Lena to Lovisa.