Inverter type motor drive unit
An inverter type drive unit for feeding AC electric power of variable parameters to an electric motor has an electronic control section, and a power converting and output section which includes one or more identical power modules, each forming a complete 3-phase output stage. The power modules are arranged side-by-side in a multiplying direction and are clamped by retaining devices to a cooling structure. The power modules are connected in parallel to DC input terminals and to AC output terminals via conductive sheets which are insulated from each other. The DC connected conductive sheets cover substantially the entire physical surface area covered by the power modules so as to accomplish an even, simultaneous and low impedance DC current supply to all power modules.
1. Inverter type motor drive unit for feeding AC electric power of variable parameters to an electric motor, comprising:
an electronic control section ( 40 ),
a power converting and output section controlled by the control section ( 40 ),
two input terminals ( 25 , 26 ) for connection to a DC power source, and
three output terminals ( 32 , 33 , 34 ) for delivering a 3-phase AC power to said electric motor,
wherein the power converting and output section comprises:
one or more identical power modules ( 11 a - 11 c ), each comprising a complete 3-phase output stage,
said one or more power modules ( 11 a - 11 c ) are multiplied by a suitable number and interconnected in parallel to meet the power demand of the actual motor size,
and wherein:
said one or more power modules ( 11 a - 11 c ) are mounted side by side in a multiplying direction (A) on a cooling structure ( 10 ), thereby covering a certain surface area substantially corresponding in size to the surface area covered by the actual number of power modules ( 11 a - 11 c ), and
said one or more power modules ( 11 a - 11 c ) are connected to said DC input terminals ( 25 , 26 ) and said AC output terminals ( 32 , 33 , 34 ) via conductive layers ( 20 , 21 , 27 a - 27 c ) which are electrically insulated from each other and extend substantially in parallel with said cooling structure ( 10 ) and covering substantially all of said certain surface area.
2. Motor drive unit according to claim 1 , wherein one of said conductive layers ( 27 a - 27 c ) is divided into three separate leads ( 27 a - 27 c ) extending in parallel to each other across said power modules ( 11 a - 11 c ) in said multiplying direction (A) and connecting said one or more power modules ( 11 a - 11 c ) in parallel to said AC output terminals ( 32 , 33 , 34 ).
3. Motor drive unit according to claim 2 , wherein:
all of said conductive layers ( 20 , 21 , 27 a - 27 c ) comprise separate metal sheets, and
a number of retaining devices ( 14 ) are arranged both to connect said metal sheets ( 20 , 21 , 27 a - 27 c ) to said one or more power modules ( 11 a - 11 c ) and to clamp said one or more power modules ( 11 a - 11 c ) into a physical heat transferring contact with said cooling structure ( 10 ).
4. Motor drive unit according to claim 3 , wherein:
two of said metal sheets ( 20 , 21 ) are connected to said DC input terminals ( 25 , 26 ), and
said one or more power modules ( 11 a - 11 c ) are connected to capacitor banks ( 13 a - 13 c ) via said two metal sheets ( 20 , 21 ).
5. Motor drive unit according to claim 3 , wherein:
each one of said retaining devices ( 14 ) comprises a clamping member ( 16 ) and a distance piece ( 15 ) for locating each metal sheet ( 20 , 21 , 27 a - 27 c ) at a specific distance from said power modules ( 11 a - 11 c ), and
said distance pieces ( 15 ) are electrically conductive and serve to establish an electrical as well as thermal contact between said metal sheets ( 20 , 21 , 27 a - 27 c ) and said power modules ( 11 a - 11 c ).
6. Motor drive unit according to claim 5 , wherein:
each one of said distance pieces ( 15 ) comprises a metallic tube element, and
each one of said clamping members ( 16 ) comprises a screw extending axially through said tube element ( 15 ).
7. Motor drive unit according to claim 1 , wherein:
all of said conductive layers ( 20 , 21 , 27 a - 27 c ) comprise separate metal sheets, and
a number of retaining devices ( 14 ) are arranged both to connect said metal sheets ( 20 , 21 , 27 a - 27 c ) to said power modules ( 11 a - 11 c ) and to clamp said one or more power modules ( 11 a - 11 c ) into a physical heat transferring contact with said cooling structure ( 10 ).
8. Motor drive unit according to claim 7 , wherein:
two of said metal sheets ( 20 , 21 ) are connected to said DC input terminals ( 245 , 26 ), and
said one or more power modules ( 11 a - 11 c ) are connected to capacitor banks ( 13 a - 13 c ) via said two metal sheets ( 20 , 21 ).
9. Motor drive unit according to claim 7 , wherein:
each one of said retaining devices ( 14 ) comprises a clamping member ( 16 ) and a distance piece ( 15 ) for locating each metal sheet ( 20 , 21 , 27 a - 27 c ) at a specific distance from said one or more power modules ( 11 a - 11 c ), and
said distance pieces ( 15 ) are electrically conductive and serve to establish an electrical as well as thermal contact between said metal sheets ( 20 , 21 , 27 a - 27 c ) and said power modules ( 11 a - 11 c ).
10. Motor drive unit according to claim 9 , wherein:
each one of said distance pieces ( 15 ) comprises a metallic tube element, and
each one of said clamping members ( 16 ) comprises a screw extending axially through said tube element ( 15 ).
11. Motor drive unit according to claim 3 , wherein the control section ( 40 ) comprises a circuit board ( 41 ) supported by at least one of said one or more power modules ( 11 a - 11 c ) in a parallel but spaced disposition relative to said metal sheets ( 20 , 21 , 27 a - 27 c ) via contact devices ( 42 ) extending through apertures in said metal sheets ( 20 , 21 , 27 a - 27 c ).
12. Motor drive unit according to claim 4 , wherein the control section ( 40 ) comprises a circuit board ( 41 ) supported by at least one of said one or more power modules ( 11 a - 11 c ) in a parallel but spaced disposition relative to said metal sheets ( 20 , 21 , 27 a - 27 c ) via contact devices ( 42 ) extending through apertures in said metal sheets ( 20 , 21 , 27 a - 27 c ).
13. Motor drive unit according to claim 5 , wherein the control section ( 40 ) comprises a circuit board ( 41 ) supported by at least one of said one or more power modules ( 11 a - 11 c ) in a parallel but spaced disposition relative to said metal sheets 5 ( 20 , 21 , 27 a - 27 c ) via contact devices ( 42 ) extending through apertures in said metal sheets ( 20 , 21 , 27 a - 27 c ).
14. Motor drive unit according to claim 6 , wherein the control section ( 40 ) comprises a circuit board ( 41 ) supported by at least one of said one or more power modules ( 11 a - 11 c ) in a parallel but spaced disposition relative to said metal sheets ( 20 , 21 , 27 a - 27 c ) via contact devices ( 42 ) extending through apertures in said metal sheets ( 20 , 21 , 27 a - 27 c ).
15. Motor drive unit according to claim 7 , wherein the control section ( 40 ) comprises a circuit board ( 41 ) supported by at least one of said power modules ( 11 a - 11 c ) in a parallel but spaced disposition relative to said metal sheets ( 20 , 21 , 27 a - 27 c ) via contact devices ( 42 ) extending through apertures in said metal sheets ( 20 , 21 , 27 a - 27 c ).
16. Motor drive unit according to claim 8 , wherein the control section ( 40 ) comprises a circuit board ( 41 ) supported by at least one of said one or more power modules ( 11 a - 11 c ) in a parallel but spaced disposition relative to said metal sheets ( 20 , 21 , 27 a - 27 c ) via contact devices ( 42 ) extending through apertures in said metal sheets ( 20 , 21 , 27 a - 27 c ).
17. Motor drive unit according to claim 9 , wherein the control section ( 40 ) comprises a circuit board ( 41 ) supported by at least one of said one or more power modules ( 11 a - 11 c ) in a parallel but spaced disposition relative to said metal sheets ( 20 , 21 , 27 a - 27 c ) via contact devices ( 42 ) extending through apertures in said metal sheets ( 20 , 21 , 27 a - 27 c ).
18. Motor drive unit according to claim 10 , wherein the control section ( 40 ) comprises a circuit board ( 41 ) supported by at least one of said one or more power modules ( 11 a - 11 c ) in a parallel but spaced disposition relative to said metal sheets ( 20 , 21 , 27 a - 27 c ) via contact devices ( 42 ) extending through apertures in said metal sheets ( 20 , 21 , 27 a - 27 c ).
19. Motor drive unit according to claim 3 , wherein:
said conductive metal sheets ( 20 , 21 , 27 a - 27 c ) are insulated relative to each other by separate insulating sheets ( 19 , 30 ) of a non-conductive material sandwiched between said metal sheets ( 20 , 21 , 27 a - 27 c ), and
said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) are arranged and fixed in a stack by said clamping members ( 16 ) and said distance pieces ( 15 ).
20. Motor drive unit according to claim 19 , wherein one or more guide elements ( 36 a - 36 c ) of an insulating material are provided with stud portions ( 37 a - 37 c ) which penetrate through openings in said metal sheets ( 20 , 21 , 27 a - 27 c ) as well as said insulating sheets ( 19 , 30 ) to, thereby, locate said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) relative to each other prior to said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) being finally fixed by said clamping members ( 16 ) and said distance pieces ( 15 ) at mounting of said stack on said cooling structure ( 10 ).
21. Motor drive unit according to claim 4 , wherein:
said conductive metal sheets ( 20 , 21 , 27 a - 27 c ) are insulated relative to each other by separate insulating sheets ( 19 , 30 ) of a non-conductive material sandwiched between said metal sheets ( 20 , 21 , 27 a - 27 c ), and
said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) are arranged and fixed in a stack by said clamping members ( 16 ) and said distance pieces ( 15 ).
22. Motor drive unit according to claim 7 , wherein:
said conductive metal sheets ( 20 , 21 , 27 a - 27 c ) are insulated relative to each other by separate insulating sheets ( 19 , 30 ) of a non-conductive material sandwiched between said metal sheets ( 20 , 21 , 27 a - 27 c ), and
said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) are arranged and fixed in a stack by said clamping members ( 16 ) and said distance pieces ( 15 ).
23. Motor drive unit according to claim 8 , wherein one or more guide elements ( 36 a - 36 c ) of an insulating material are provided with stud portions ( 37 a - 37 c ) which penetrate through openings in said metal sheets ( 20 , 21 , 27 a - 27 c ) as well as said insulating sheets ( 19 , 30 ) to, thereby, locate said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) relative to each other prior to said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) being finally fixed by said clamping members ( 16 ) and said distance pieces ( 15 ) at mounting of said stack on said cooling structure ( 10 ).
24. Motor drive unit according to claim 22 , wherein one or more guide elements ( 36 a - 36 c ) of an insulating material are provided with stud portions ( 37 a - 37 c ) which penetrate through openings in said metal sheets ( 20 , 21 , 27 a - 27 c ) as well as said insulating sheets ( 19 , 30 ) to, thereby, locate said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) relative to each other prior to said metal sheets ( 20 , 21 , 27 a - 27 c ) and said insulating sheets ( 19 , 30 ) being finally fixed by said clamping members ( 16 ) and said distance pieces ( 15 ) at mounting of said stack on said cooling structure ( 10 ).
25. Motor drive unit according to claim 1 , wherein:
said conductive layers ( 20 , 21 , 27 a - 27 c ) comprise separate metal sheets ( 20 , 21 , 27 a - 27 c ), and
said DC input terminals ( 25 , 26 ) and said AC output terminals ( 32 , 33 , 34 ) are located at opposite ends of said metal sheets ( 20 , 21 , 27 a - 27 c ) in relation to said multiplying direction (A).
26. Motor drive unit according to claim 2 , wherein:
said conductive layers ( 20 , 21 , 27 a - 27 c ) comprise separate metal sheets ( 20 , 21 , 27 a - 27 c ), and
said DC input terminals ( 25 , 26 ) and said AC output terminals ( 32 , 33 , 34 ) are located at opposite ends of said metal sheets ( 20 , 21 , 27 a - 27 c ) in relation to said multiplying direction (A).
27. Motor drive unit according to claim 1 , wherein a signal bus means 44 a , 44 b ) extends across said one or more power modules 11 a - 11 c ) in said multiplying direction (A) and is arranged to connect said control section ( 40 ) to each one of said one or more power modules 11 a - 11 c )and communicating signals between said control section ( 40 ) and said one or more power modules 11 a - 11 c ).
28. Motor drive unit according to claim 27 , wherein said signal bus means 44 a , 44 b ) comprises at least one circuit board 44 a , 44 b ).
29. Motor drive unit according to claim 2 , wherein a signal bus means 44 a , 44 b ) extends across said one or more power modules 11 a - 11 c ) in said multiplying direction (A) and is arranged to connect said control section ( 40 ) to each one of said one or more power modules 11 a - 11 c ) and communicating signals between said control section ( 40 ) and said one or more power modules 11 a - 11 c ).
30. Motor drive unit according to claim 27 , wherein said signal bus means 44 a , 44 b ) comprises at least one circuit board 44 a , 44 b ).