It alleges that the products are exactly the same as those Sinovel purchased from AMSC in 2008.
AMSC is demanding that Sinovel instantly stops the acts of infringing wind turbine software copyrights, deletes or destroys all infringed AMSC software on Sinovel turbines, and compensates AMSC for an economic loss of 37.8 million yuan (about $6 million US).
Sinovel said yesterday that it received a notice from the Beijing court on 21 October.
The case has not heard by the court as yet, and Sinovel said it is preparing evidence to actively respond to the claims.
In April, Sinovel refused shipment of AMSC components, saying AMSC products and services failed to meet demands.
It precipitated a multi-million dollar legal battle, centering on an AMSC accusation of intellectual property (IP) theft regarding an upgrade of Sinovel's 1.5MW turbine fleet.
AMSC then extended the battle lines by petitioning the Hainan provincial court to prohibit supplier Dalian Guotong from infringing its copyright. According to reports, Sinovel owns 22.5% of Dalian Guotong.
Earlier this month Sinovel filed a counterclaim to Beijing Arbitration Commission requesting the arbitration tribunal to reject all the arbitration claims made by AMSC and rule AMSC to compensate Sinovel CNY 79.9 million ($12 million) for economic losses from breach of contracts.