Looking in FLAC format:
Thunder Force III/Tecno Soft GAME MUSIC COLLECTION VOL.3 (http://vgmdb.net/album/456)

Thunder Force IV Special Digest (http://vgmdb.net/album/10552)

Best of Thunder Force (http://vgmdb.net/album/8831)

Technosoft GAME MUSIC COLLECTION VOL.15 ~ BEST OF THUNDER FORCE (http://vgmdb.net/album/520)

THUNDER FORCE Chuushinzou / Yosenabe Arrange Sound Tracks (http://vgmdb.net/album/15217)

Lost Technology ~ Thnder Force Sound Track (http://vgmdb.net/album/523)

Thunder Force Renaissance (http://vgmdb.net/album/10332)

ABSOLUTE AREA -project THUNDER FORCE VI- (http://vgmdb.net/album/544)

Thunder Force VI SOUNDTRACK DEMO (http://vgmdb.net/album/10828)

Technosoft GAME MUSIC COLLECTION VOL.10 ~ Technology ~ 2013 Thunder Force V Original Sound Track (http://vgmdb.net/album/38586)

Technosoft GAME MUSIC COLLECTION VOL.22 ~ ThunderForce II 2014 Original Sound Track (http://vgmdb.net/album/45652)

Technosoft GAME MUSIC COLLECTION VOL.5 ~ ThunderForce IV 2014 Original Sound Track (http://vgmdb.net/album/45934)

Technosoft GAME MUSIC COLLECTION VOL.15 ~ Best of ThunderForce 2014 Original Sound Track (http://vgmdb.net/album/45939)


Found:
Technosoft GAME MUSIC COLLECTION VOL.10 ~ Technology ~ Thunder Force V Original Sound Track (http://vgmdb.net/album/482)

Technosoft GAME MUSIC COLLECTION VOL.3 ~ ThunderForce III 2014 Original Sound Track (http://vgmdb.net/album/45933)

BROKEN THUNDER -project THUNDER FORCE VI- (http://vgmdb.net/album/542)