SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, D.C. 20549

SCHEDULE 13G

(Rule 13d-102)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO RULES 13d-1(b), (c), AND (d) AND AMENDMENTS THERETO FILED

PURSUANT TO RULE 13d-2

(Amendment No. 1)^*

American Superconductor Corporation

(Name of Issuer)

Common Stock

(Title of Class of Securities)

030111207

(CUSIP Number)

December 31, 2018

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

The information required in the remainder of this cover page shall not be deemed to be “filed” for the purpose of Section 18 of the Securities Exchange Act of 1934 (“Act”) or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

SCHEDULE 13G

American Superconductor Corporation

114 East Main St.

Ayer, Massachusetts 01432

Thomas A. Satterfield, Jr.

Thomas A. Satterfield, Jr.

2609 Caldwell Mill Lane

Birmingham, Alabama 35243

Incorporated by reference from Item 4 of the Cover Page.

Incorporated by reference from the Cover Page.

Incorporated by reference from the Cover Page.

Not Applicable.

Incorporated by reference from Item 9 of the Cover Page.

Incorporated by reference from Item 11 of the Cover Page.

Incorporated by reference from Item 5 of the Cover Page.

Incorporated by reference from Item 6 of the Cover Page.

Incorporated by reference from Item 7 of the Cover Page.

Incorporated by reference from Item 8 of the Cover Page.

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than 5 percent of the class of securities, check the following ☐.

With respect to the beneficial ownership reported for Thomas A. Satterfield, Jr., 30,000 shares are held jointly with Mr. Satterfield’s spouse; 95,000 shares are held by Tomsat Investment & Trading Co., Inc., a corporation wholly owned by Mr. Satterfield and of which he serves as President; 420,135 shares are held by Caldwell Mill Opportunity Fund, which fund is managed by an entity of which Mr. Satterfield owns a 50% interest and serves as Chief Investment Manager; and 10,000 shares are held by Riachuello Ranch LLC, a closely held limited liability company in which Mr. Satterfield owns an approximately 11.1% interest and for which he serves as President.

Additionally, Mr. Satterfield has limited powers of attorney for voting and disposition purposes with respect to the following shares: A.G. Family L.P. (429,630 shares); Thomas A. Satterfield, Sr. (30,000 shares); Jeanette Satterfield Kaiser (25,000 shares); Richard W. Kaiser (10,000 shares); David A. Satterfield (15,000 shares); Parker Satterfield, under the Uniform Gifts to Minors Act (2,000 shares); Alexandria Pontikes (1,000 shares); and Camille Pontikes (1,000 shares). These individuals and entities have the right to receive or the power to direct the receipt of the proceeds from the sale of their respective shares.

Not Applicable.

Not Applicable.

Not Applicable.

By signing below, I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.