GB2490495A

GB2490495A - A modular and stackable motor controller

Info

Publication number: GB2490495A
Application number: GB1107207.1A
Authority: GB
Inventors: Gary Squire; Robert Taylor
Original assignee: Sevcon Ltd
Current assignee: Sevcon Ltd
Priority date: 2011-04-28
Filing date: 2011-04-28
Publication date: 2012-11-07
Anticipated expiration: 2031-04-28
Also published as: GB2490495B; GB201107207D0

Abstract

An electric motor controller 20 having a front face and a rear face, the front face carrying a plurality of AC output couplings 24a,24b,24c and the back face carrying a converter 28 configured to convert a received DC supply into an output AC supply, the AC output couplings 24a,24b,24c being disposed symmetrically about an axis of symmetry of the controller on the front face of the controller (x). The controller 20 may also comprise a plurality of DC input couplings 26a,26b,26c to provide a DC supply to the converter 28, wherein at least two of the DC input couplings 26a,26b,26c are disposed symmetrically about an axis of symmetry on the face of the controller (x). The motor controller may also share a cooling system with a motor, where the motor and the controller are positioned back-to-back. The cooling system may be at least one of a heatsink and a coolant circulation system. The present invention relates to modular motor controllers which are light-weight and capable of mounting on individual drive wheels of an electric vehicle.

Description

A MODULAR AND STACKABLE MOTOR CONTROLLER

The present invention relates to a controller for an electric motor and a modular motor-controller assembly.

In electric vehicles, to avoid the weight and cost of a differential individual (separate) motors may be used to drive individual wheels.

The environmental problems associated with carbon dioxide vehicle emissions are well known. A proposed solution is replacement of the internal combustion engine with the electric motor for vehicles. Each electric motor requires a controller. In the case where the motor is a three-phase motor, the controller has an inverter for converting the DC supply to AC for the motor. This process generates heat from the rapid switching and on the state voltage drop of high power transistors. Heat is also generated in the motor due to ohmic (12R) heating in the windings, eddy currents and due to friction.

Each motor and each controller requires a cooling system. Typically, cooling is achieved by running fluid coolant past a heat sink or manifold to absorb thermal energy. Although a single pump may be used, each cooling system will comprise a system of pipes to enable fluid circulation. Thus in an arrangement having two motors and two motor-controllers, four sets of cooling apparatus (including heat sinks manifolds and pipework) must be provided.

The presence of a plurality of motors, controllers, associated electrical components and cooling components means that the design and assembly of electric vehicle traction systems is a non trivial task.

A further problem is that the high current required for the motors (of the order of hundreds of Amps), leads to losses when spaced-apart motors and controllers are connected by long wires. Such wiring also presents safety issues, such as a risk of electrocution to emergency services personnel needing to cut in to a crashed vehicle.

The inventors in the present case have recognised a need to reduce the weight, bulk and complexity of electric traction motors and motor-controller assemblies.

Aspects and examples of the invention are set out in the claims and address at least pad of the above described technical problem.

In an aspect there is provided an electric motor controller having a plurality of electronic or electrical components distributed symmetrically about an axis of symmetry of the controller. This has the advantage that a single controller circuit board can be manufactured and simply rotated to enable controllers to be stacked together back-to-back with common input/output couplings. The inventors in the present case have appreciated that despite the perceived problems of arranging multiple heat sources in close proximity it is advantageous to assemble electric motor controllers together and that, without this symmetry it is necessary to provide different "right-handed" and "left-handed" controllers, or to adapt input/output couplings where controllers are to be assembled together.

An electric motor controller may comprise at least one power supply input coupling and a monitoring coupling adapted for monitoring an operational parameter of another controller, wherein the monitoring coupling and the power supply input coupling are disposed in positions which are mutually symmetric about the axis of symmetry of the controller. This has the advantage that monitoring of operation of one controller (such as the current drawn from a power supply) can be monitored by an adjacent controller board using compact, shod physical connections.

In some possibilities an electric motor controller comprises first, second and third output couplings for providing respective first, second and third motor control output signals and comprises a control means operable to cause the third output coupling to provide the first motor control output signal and to cause the first output coupling to provide the third motor control output signal such that the first and third motor control output signals are transposed. This has the advantage that two identical controllers can be assembled back to back to provide three-phase outputs in the same physical orientation with respect to the controllers.

in some possibilities said plurality of components and/or at least one of the input and output couplings are arranged on a first face of the controller, the controller comprising at least one power transistor arranged on a second face of the controller, opposite to the first face. This has the advantage of enabling a pair of electric motor controllers to be assembled to a single heat sink disposed between the controllers because the transistors of the controllers can be thermally coupled to the heat sink. It is also possible to provide first and second electric motors, wherein the first electric motor is disposed adjacent the first face of one of the electric motor controllers and the second electric motor is disposed adjacent the first face of the other electric motor controller to enable the heat sink and the electric motors to be thermally coupled to a single cooling manifold.

This further simplifies the arrangement of motors and controllers because a single cooling system can be provided with a single pair of fluid couplings for the in flow of and out flow of cooling fluid through the manifold.

In an aspect there is provided an electric motor controller comprising at least one output coupling, wherein the output coupling is disposed symmetrically about an axis of the controller. This symmetry enables the controller to be assembled with another controller and with electric motors and cooling apparatus in a manner that reduces the weight, volume and complexity of the assembly.

In one example, there is provided an electric motor controller comprising a plurality of output couplings, wherein the output couplings are disposed symmetrically on a front face the controller about an axis of that face, and wherein at least one of the couplings is not disposed on the axis. In another example, there is provided a motor controller comprising three output couplings disposed symmetrically on a front face of the controller about an axis of that face, wherein at least one of the couplings is not disposed on the axis. In examples where both of a first and second controller have this arrangement of output terminals, the output terminals of the first controller provide a mirror-image to the output terminals of a second controller when the controllers are aligned back-to-back.

Also described herein is a modular motor-controller assembly comprising motor-controller assemblies wherein each motor-controller assembly comprises an electric motor controller and an electric motor coupled to the electric motor controller, and cooling apparatus configured to cool the motors and controllers. The cooling apparatus comprises a heat sink. In one possibility, each of the controllers comprises one output coupling, wherein the output coupling is disposed symmetrically about an axis of the controller. In another possibility, each of the controllers comprises a plurality of output couplings, wherein the output couplings are disposed symmetrically on a face of the controller about an axis of that face, and wherein at least one of the couplings is not disposed on the axis. In another possibility, each of the controllers comprises three output couplings, wherein the output couplings are disposed symmetrically on a face of the controller about an axis of that face, and wherein at least one of the couplings is not disposed on the axis. In one possibility the controllers have output couplings disposed in symmetrical positions about an axis of symmetry of the controller. A heat sink may be provided between the controllers and/or the motors. A cooling manifold may be provided to cool the heat sinks of the controllers/motors. In one possibility, the heat sink is integrated with the cooling manifold.

Using this arrangement, only one set of cooling apparatus need be provided for two motor-controller assemblies, with the effect that weight, volume and complexity are reduced. A further advantage is that the provision of controllers having symmetrically identical output couplings allows the use of motors having the same design specification.

A further advantage is that the modular assembly may be provided within an enclosure, providing convenient handling of the assembly and increased ease of assembling it within a vehicle or vehicle engine bay. The enclosure may provide electrical connections and fluid coolant couplings configured to serve both controllers and/or both motors, thereby further reducing weight, size and complexity of the apparatus.

In one example, the assembly is configured to provide differential drive. In one possibility, differential drive may be used to drive front and back wheels of a vehicle. In another possibility, differential drive may be used to drive left and right wheels of a vehicle. In another example, the controllers of the assembly may be coupled to coordinate driving of the motors.

Embodiments of the invention will now be described in detail, by way of example only, with reference to the accompanying drawings, in which: Figure 1 illustrates a system comprising an electric motor and controller; Figure 2A and 2B illustrate the front surfaces of first and second controllers according to the invention; Figure 3 shows a modular motor-controller assembly comprising two motors and two controllers with a heat sink serving both controllers and a cooling manifold; and, Figure 4 shows first and second controllers in profile, each controller having an extended terminal for monitoring current on the other controller.

In overview, the electric motor system 10 comprises motor 2 and a controller 20 to control operation of the motor.

The controller 20 is configured to derive a three-phase alternating current (AC) supply for the motor 2 from a direct current (DC) power source 6, in this example a battery.

The electric motor system 10 also comprises a cooling apparatus 4. Cooling apparatus 4 is coupled to both the motor 2 and controller 20 to remove heat produced by the operation of the motor 2 and controller 20. A drive output of the motor provides torque to drive a drive plate 8 coupled to a drive axle of a vehicle.

The controller 20 is configured to perform inversion, filtering and conditioning processing on the DC output of the power source 6 to provide the motor with the required AC power source.

The controller 20 comprises an inverter 28 to convert a DC input to a three-phase AC output for use by the motor 2. Any suitable form of inverter may be used. In a preferred example, an insulated gate bipolar transistor (IGBT) inverter is used. Preferred characteristics of the IGBT converter include high efficiency and fast switching.

Figure 2A shows a front view of one example of a controller 20 comprising a printed circuit board (PCB) 22. Figure 2A also shows a controller casing 21 within which the controller is housed. The PCB 22 carries supply contact fittings 26a, 26b and 26c each fitting may comprise a current transducer for sensing current passed through the fitting.

Supply contact fitting 26b comprises a supply contact B+ for coupling to a first terminal of a DC supply, not shown. Supply contact fitting 26c comprises supply contact B-for coupling to a second terminal of the DC supply (not shown). The PCB 22 also carriesAC output terminals 24a, 24b and 24c and an inverter 28 (shown in dashed lines in Figure 2A). Supply contact B+ is electrically coupled by copper arm 35b to battery terminal 32a and 32b mounted to extension 33 of the casing 21 through which wires run to provide for connection to the power source 6. Supply contact B-is electrically coupled by copper arm 35a to battery terminal 32b mounted to the extension of the casing 21.

The DC supply contacts 26b, 26c are coupled to respective inputs of the inverter 28.

The inverter 28 outputs are coupled to AC output terminals 24a, 24b, 24c. Each of the output terminals is operable to be coupled to a respective phase winding of a motor 2.

The AC output terminals 24a, 24b, 24c are disposed symmetrically about an axis x-x of PCB 22. In this example, the DC supply contact fittings 26a, 26b, 26c are similarly symmetrically disposed.

PCB 22 may comprise other functionality 30 which may include, for example, microprocessors, power supplies, capacitors and inductors configured for control filtering and conditioning.

Figure 2B shows a front view of a second controller 20' comprising PCB 22'. Figure 2B also shows controller casing 21' within which the controller 20' is housed. Controller 20' is the same as controller 20 except for the orientation of the PCB 22'. Compared to PCB 22 and controller casing 21, PCB 22' is rotated through 180 degree relative to its controller casing 21'. Compared to controller casing 21 and PCB 22, controller casing 21' is inverted relative to PCB 22' with respect to an axis normal to the axis x-x.

The effect of the PCB rotation is that when the controllers are disposed with their edges 23, 23' aligned and their back faces towards one another, the output terminals 24a', 24b', 24c' of controller 20' are aligned with the output terminals 24a, 24b, 24c. The supply contact fittings 26a, 26b, 26c of controller 20 are aligned with the supply contact fittings 26a', 26b', 26c' of controller 20'. The casing inversion means that the profiles of controller casings 21, 21' coincide. When the controllers are arranged in this way, a heat sink may be positioned between their respective back faces adjacent the power transistors of the inventors (the principal heat source is the controller). The heat sink operates to cool both controllers simultaneously, so that separate heat sinks need not be provided for the controllers. Figure 3 illustrates an arrangement where first and second controllers are arranged on an axis 10 either side of a heat sink 12.

The controllers described above enable formation of modular assemblies consisting of sets of motors and associated controllers. The option of having identical PCBs 22, 22' which can simply be rotated for assembly together in a back to back formation simplifies production of the PCBs and assembly requirements of modular stacks of motors and controllers.

Referring in more detail to Figure 3, there is illustrated a modular assembly 50 contained within an enclosure 40 and comprising first and second motors 2, 2', first and second controllers 20, 20' and common cooling apparatus comprising a heat sink 12 and a cooling manifold 14, and supply couplings 160 running through the extensions 33 to enable the battery terminals 32a and 32b to be coupled to power source 6.

The motors and controllers are disposed on an axis 10 configured to be coupled to the drive plate 8. First motor 2 is disposed on a first end of the axis 10. First motor 2 is adjacent the front face 34 of the first controller 20. The back face 36 of the first controller carrying the inverter is adjacent and in thermal contact with heat sink 12. Heat sink 12 is also adjacent and in thermal contact with the back face 36' of the second controller 20'. The front face 34' of the second controller 20' is adjacent second motor 2' which is disposed on the second end of the axis 10. First and second motors and first and second controllers share a cooling manifold 14 which may be integrated with the enclosure 40.

Cooling manifold 14 has an inlet 16 and an outlet 18. The cooling manifold 14 is in physical and thermal contact with heat sink 12 and is in thermal contact with first and second motors 2, 2'.

DC supply couplings 160 are coupled to the first and second controllers 20, 20'. The first motor 2 is in electrical contact with the first controller 20. Electrical contact is achieved through an electrical coupling between each of the output terminals 24a, 24b, 24c and a phase winding in the motor 2. The second motor 2' is in electrical contact with the second controller 20'. Electrical contact is achieved through an electrical coupling between each of the output terminals 24a', 24b', 24c' and a phase winding in the motor 2'.

DC power is supplied to controllers 20 and 20' via DC supply couplings 160. The first controller 20 converts the DC supply to three-phase AC for the first motor 2. The AC signal produces a torque on the rotor of the first motor 2 which produces a drive at the first end of the axis 10. The second controller 20' and motor 2' operate in the same way to produce drive at the second end of the axis 10. The motor outputs may be coupled to respective drive coupling, e.g. drive plates, to drive respective drive shafts.

In one possibility the first and second controllers 20, 20' are in electrical contact. That is, DC terminals B+, B-of the first controller 20 are electrically coupled to the corresponding terminals B+, B-of the second controller 20'. Each controller has a B+ terminal on the front face (26b, 26b') and one B-terminal on the rear face (26a for controller 20 and 26c' on controller 20'). The B-terminals pass through a current sensor on the other unit allowing monitoring of performance of both controllers to be done by each controller in the pair.

The cooling system operates as follows. Cooling manifold 14 receives fluid coolant via inlet 16. The coolant absorbs heat from the first and second motors 2, 2'. The manifold 14 also provides fluid to the heat sink 12, which removes heat from the inverters 28, 28' disposed on the respective back surfaces 34, 34' of the first and second controllers 20, 20' (as shown in Figure 4). In this example, fluid supplied to the heat sink circulates back to the cooling manifold. Cooling fluid leaves the cooling manifold via outlet 18.

In a possibility, a plurality of motors and controllers in a ratio of one motor to one controller are disposed on the axis 10 and within the enclosure 40. Controllers arranged back to back may share a heat sink. At most, two controllers may share a given heat sink. All heat sinks are in physical and thermal contact with the cooling manifold 14.

Generally the motors will stacked at the ends of the axis 10 in order that drive be produced at the ends of the axis 10.

An advantage of the modular assembly 50 is that first and second controllers 20, 20' share a cooling unit, as described above, rather than each controller being provided with a cooling unit. Therefore, in any engine having more than one motor-controller pairing, the modular assembly substantially reduces the engine's weight and volume by eliminating at least one cooling unit 4.

In a possibility, the enclosure 40 has integrated electrical connections (e.g. for phase to stator windings, rotor position encoder and DC input). These serve to further optimize size and weight of the combined apparatus.

It will be appreciated that the relative rotation of the second PCB 22' results in the order of the electrical terminals being inverted compared to those of the first PCB 22. This means that, when the first and second controllers 20, 20' are arranged as shown in Figure 3, their output terminals 24, 24' are aligned as follows. Terminal 24a is aligned with 24c'. Terminal 24b is aligned with 24b'. Terminal 24c is aligned with 24a'. In this example, terminals 24a and 24a' output a first electrical phase, terminals 24b and 24b' output a second phase and terminals 24c and 24c' output a third phase. When identical motors are connected to the controllers as shown in Figure 3 and identical motor-controller couplings are used, motors 2 and 2' produce a torque in opposite directions. It may be desirable that the output terminals of the controllers line up so that terminals outputting like phases are aligned. Optionally, therefore, a switch may be provided on the first F'CB 20 or the second PCB 20' to invert the phases output from terminals 24a and 24c and 24a' and 24c', respectively. Alternatively, circuitry may be provided to switch the phases of those terminals automatically. In possibilities where multiple controllers and motors are stacked up alongside one another, such automatic switching may serve to coordinate the phase outputs across the whole stack of controllers.

It follows from the rotation of PCB 22' that the supply contact fittings 26' are also inverted. The unused contact fitting can be used to perform an additional function, such as monitoring current through another controller. An arrangement for performing current monitoring is illustrated in Figure 4, which shows first and second controllers 20, 20' arranged back to back either side of a common heat sink 12. In the example shown, the unused contact 26c of the first controller 20 is coupled to a current monitoring transducer of the second controller 20'. The coupling is achieved by means of an extended terminal 38 passing through the inverter 22 and the heat sink 12. Similarly, the unused contact 26a' of the second controller 20' is coupled to a current monitoring output of the first controller 20 via an extended terminal 38' passing through inverter 28' and heat sink 12.

In another possibility, power supply 6 is connected to supply contacts of the first and second controllers 20, 20' such that a positive battery terminal is provided on each respective controller by supply contacts 26b and 26b', and a negative battery terminal is provided on each respective controller by supply contacts that are aligned when the controllers are arranged back to back. With reference to Figures 2A and 2B, that is to say, supply contact 24c' provides the negative battery terminal on the second controller 20' when supply contact 24a provides the negative battery terminal on the first controller 20, and supply contact 24a' on the second controller 20' provides the negative battery terminal when supply contact 24c provides the negative terminal on the first controller 20.

This allows the controllers 20, 20' to be connected in parallel to the power supply 6.

As described above, the motor is a three-phase motor and the supply produced by controller 20 is three-phase AC. In another example, the motor may be a single-phase motor and the supply produced by the controller single-phase AC. In another example the motor may be a two-phase motor and the supply produced by the controller two-phase AC. As described above, the power source 6 comprises a battery. In other examples the power source may be a fuel cell or an electric double-layer capacitor (EDLC) or other source of DC power.

Although the inverter described employs IGBT other voltage controlled impedances may be used, such as MOS-FETs other types of IG-FET or BJTs.

Claims

CLAIMS1. An electric motor controller for an electric motor comprising at least one output coupling and at least one input coupling, wherein at least one of the input coupling and the output coupling is disposed symmetrically about an axis of the controller.
2. An electric motor controller according to claim 1, comprising a plurality of output couplings, wherein the output couplings are disposed symmetrically on a face of the controller about an axis of that face, and wherein at least one of the couplings is not disposed on the axis.
3. An electric motor controller according to claim I or 2, comprising three output couplings, wherein the output couplings are disposed symmetrically on a face of the controller about an axis of that face, and wherein at least one of the couplings is not disposed on the axis.
4. An electric motor controller according to any preceding claim, comprising at least one supply contact to receive a power input, and an inverter, preferably wherein at least one supply contact comprises two supply contacts.
5. An electric motor controller according to claim 4, wherein the at least one supply contact and the output couplings are disposed on a front surface of the controller and the inverter is disposed on a back surface of the controller.
6. An electric motor controller according to claim 4 or 5, comprising supply contacts to receive a DC input, three output contacts and an inverter for converting the DC input to a three-phase AC output.
7. An electric motor controller according to any of claims 4 to 6, wherein the inverter is a semiconductor device such as an IGBT inverter or a MOSFET inverter.
8. An electric motor controller according to any of claims 5 to 7, comprising first and second supply contacts wherein the first supply contact is configured for coupling to a first terminal of a power source the second contact is configured for coupling to a second terminal of said power source and is arranged to enable a mutually similar controller disposed adjacent the back face of the controller to couple to the second contact for monitoring current flow through the second contact.
9. An electric motor controller according to claim 8, wherein conductive strips are provided to couple between a supply contact and respective power source terminals.
10. An electric motor controller according to any preceding claim, wherein the controller is provided within a casing which provides couplings to connect the controller to a power supply.
11. An electric motor controller according to claim 10, wherein the couplings to connect the controller to the power supply are provided within an extension of the casing.
12. A motor-controller assembly comprising an electric motor controller according to any preceding claim and an electric motor coupled to the electric motor controller.
13. A modular motor-controller assembly comprising a plurality of controllers according to any of claims I to 11 each coupled to a motor and cooling apparatus to cool the motors and controllers.
14. A modular motor-controller assembly according to claim 13, wherein the cooling apparatus comprises at least one heat sink, and wherein the controllers are arranged adjacent one another such that two adjacent controllers share a heat sink.
15. A modular motor-controller assembly comprising two motor-controller assemblies according to claim 12, and cooling apparatus to cool the motors and controllers.
16. A modular motor-controller assembly according to claim 15, wherein the cooling apparatus comprises a heat sink in thermal contact with the controllers.
17. A modular motor-controller assembly according to claim 15 or 16, wherein the controllers are arranged back-to-back and the heat sink is provided between the controllers, the heat sink being in thermal contact with the back surfaces of the controllers.
18. A modular motor-controller assembly according to any of claims 15 to 17, wherein the cooling apparatus comprises a cooling manifold in thermal contact with the motors.
19. A modular motor-controller assembly according to any of claims 15 to 18, wherein the controllers are symmetrically identical.
20. A modular motor-controller assembly according to any of claims 15 to 19, wherein one controller has an orientation relative to the other such that the output couplings of the controllers are aligned when the controllers are arranged back to back.
21. A modular motor-controller assembly according to any of claims 15 to 20, wherein components of one of the controllers are a geometrical mirror-image of the components of the other controller when the controllers are arranged back to back.
22. A modular motor-controller assembly according to any of claims 15 to 21, wherein the controllers have the same design specification in respect of their components and the configuration of their components.
23. A modular motor-controller assembly according to any of claims 15 to 22, wherein the controller casings are not rotationally symmetrical and one of the controllers is inverted relative to the controller casing of the other controller, such that the casings coincide when the controllers are arranged back to back.
24. A modular motor-controller assembly according to claim 23, wherein supply couplings are provided within coincident extensions of the controller casings to connect the controllers to a power source.
25. A modular motor-controller assembly according to any of claims 15 to 24, wherein -14 -each motor is adjacent a respective one of the controllers.
26. A modular motor-controller assembly according to any of claims 15 to 25, whereinthe motors have the same design specification.
27. A modular motor-controller assembly according to any of claims 15 to 26, wherein the two motor-controller assemblies are disposed on an axis and wherein the motors are disposed so as to provide drive at respective ends of the axis.
28. A modular motor-controller assembly according to any of claims 15 to 27, wherein the assembly is configured to enable the motors to produce a differential drive.
29. A modular motor-controller assembly according to any of claims 15 to 28, wherein the controllers are coupled to coordinate driving of the motors.
30. An electric motor controller having a front face and a rear face, the front face carrying a plurality of DC input couplings and a plurality of AC output couplings and the back face carrying a converter, the converter having inputs coupled to the DC input couplings and outputs coupled to the AC output couplings, the converter being configured to convert a received DC supply into an output AC supply, the AC output couplings being symmetrically disposed on the front face of the controller.
31. An electric motor controller according to claim 30, wherein at least one of the DC input couplings is symmetrically disposed on the front face of the controller.
32. An electric motor controller according to claim 30 or 31, wherein the DC input couplings are coupled via respective conductive strips to corresponding power supply input couplings.
33. An electric motor controller according to claim 30 or 31, wherein three DC input couplings are provided and two of the DC input couplings are coupled via respective copper strips to corresponding power supply input couplings.
34. An electric motor controller according to claim 32 or 33, wherein the controller has a casing and the power supply input couplings are located in a casing extension.
35. A kit comprising at least two electric motor controllers according to any of claims 30 to 34, wherein the electric motor controllers are configured to be positioned back-to-back with their rear faces facing.
36. A kit comprising at least two electric motor controllers according to claim 34, wherein the electric motor controllers are configured to be positioned back-to-back with their rear faces facing and the casings of the electric motor controllers are mirror images of one another so that when the controllers are positioned back-to-back, the extensions enable connection of the power supply input couplings of the controllers to a power supply source via conductors passing through the extensions.
37. An electric motor-controller assembly comprising an electric motor controller according to any of claims 30 to 31 and a motor, the controller and the motor sharing a cooling system.
38. A modular motor assembly comprising a plurality of electric motor controllers according to any of claims 30 to 34 and a respective motor for each electric motor controller, the electric motor controllers and motors being arranged such that adiacent electric motor controllers are positioned back-to-back and share a cooling system of the assembly.
39. An assembly according to claim 38, wherein the cooling system comprises at least one of heatsink and a coolant circulation system.
40. An assembly according to claim 39, wherein the cooling system comprises a cooling manifold extending over the motors and the heat sink.
41. An electric motor controller comprising output means for coupling to a motor, wherein the output means is symmetrically disposed on the face of the controller.
42. An electric motor-controller assembly comprising one or more controllers according to any of claims I to 11 and 30 to 34, each for controlling a corresponding motor of the assembly
43. A vehicular electric motor controller according to any of claims I to 11, 30 to 34 and 42.
44. A vehicular electric motor-controller assembly according to any of claims 12 to 29 and 37 to 40.
45. An electric motor controller substantially as hereinbefore described with reference to and/or as illustrated in the accompanying drawings.
46. A modular motor-controller assembly substantially as hereinbefore described with reference to and/or as illustrated in the accompanying drawings.
47. A vehicle having an electric motor controller according to any of claims I to 11, 30 to 34, 42 and 44 or a motor-controller assembly according to any of claims 12 to 29, 37 to 40 and 45.
48. An electric motor controller having a plurality of electronic or electrical components distributed symmetrically about an axis of symmetry of the controller.
49. An electric motor controller according to claim 48 comprising at least one power supply input coupling and a monitoring coupling adapted for monitoring an operational parameter of another controller, wherein the monitoring coupling and the power supply input coupling are disposed in positions which are mutually symmetric about the axis of symmetry of the controller.
50. An electric motor controller according to claim 48 or 49 comprising at least one motor control output coupling disposed symmetrically about an axis of symmetry of the controller.
51. An electric motor controller according to claim 50 in which the at least one motor control output coupling comprises a plurality of motor control output couplings.
52. An electric motor controller according to claim 51 in which the plurality of motor control output couplings comprise first, second and third output couplings for providing respective first, second and third motor control output signals and comprising a control means operable to cause the third output coupling to provide the first motor control output signal and to cause the first output coupling to provide the third motor control output signal such that the first and third motor control output signals are transposed.
53. An electric motor controller according to any of claims 48 to 52 in which said plurality of components and/or at least one of the input and output couplings are arranged on a first face of the controller, the controller comprising at least one power transistor arranged on a second face of the controller, opposite to the first face.
54. An apparatus comprising a pair of electric motor controllers according to claim 53 assembled to a heat sink disposed between the controllers to enable the transistors of the controllers to be thermally coupled to the heat sink.
55. An apparatus according to claim 54 as dependent upon claim 49 wherein the pair of controllers are arranged such that the monitoring coupling of each controller is aligned with the power supply input coupling of the other controller.
56. An apparatus according to claim 54 or 55 further comprising first and second electric motors, wherein the first electric motor is disposed adjacent the first face of one of the electric motor controllers and the second electric motor is disposed adjacent the first face of the other electric motor controller to enable the heat sink and the electric motors to be thermally coupled to a single cooling manifold.
57. An apparatus according to claim 56 further comprising the cooling manifold.
58. An apparatus according to claim 57 wherein the cooling manifold comprises a fluid flow path for a flow of cooling fluid to cool the manifold, preferably wherein the fluid comprises a liquid.
59. An apparatus comprising an electric motor controller according to claim 53 and an electric motor disposed adjacent the first face of the electric motor controller to enable the electric motor and the electric motor controller to be assembled to a heat sink disposed adjacent the second face of the electric motor controller to enable the at least one transistor to be thermally coupled to said heat sink.
60. An apparatus according to claim 59 further comprising said heat sink.
61. An apparatus according to claim 59 or 60 comprising a cooling manifold adapted for coupling to the motor and to said heat sink.
62. An electric motor assembly comprising an electric motor and a first electric motor controller thermally coupled to a heat sink, wherein the electric motor and the heat sink are thermally coupled to a single cooling manifold.
63. An electric motor assembly according to claim 62 further comprising a second electric motor and a second electric motor controller, wherein the second electric motor controller is thermally coupled to the heat sink and the second electric motor, is thermally coupled to the single cooling manifold.
64. An apparatus according to claim 61, 62 or 63 wherein the cooling manifold comprises a fluid flow path for a flow of cooling fluid to cool the manifold, preferably wherein the fluid comprises a liquid.
65. An apparatus according to any of claims 59 to 64 in which the electric motor controller(s) and electric motor(s) and heat sink are disposed in a common casing.AMENDMENTS TO CLAIMS HAVE BEEN FILED AS FOLLOWSCLAIMS1. An electric motor controller having a front face and a rear face, the front face carrying a plurality of AC output couplings and the back face carrying a converter configured to convert a received DC supply into an output AC supply, the AC output couplings being disposed symmetrically about an axis of symmetry of the controller on the front face of the controller.2. An electric motor controller according to claim 1, comprising a plurality of DC input couplings to provide a DC supply to the converter wherein at least two of the DC input couplings are disposed symmetrically about an axis of symmetry of the controller on the front face of the controller.C\i 3. An electric motor controller according to claim 2, wherein the DC input couplings " 15 are coupled via respective conductive strips to corresponding power supply input CO couplings.(0 4. An electric motor controller according to claim 2 or 3, wherein three DC input C'\I couplings are provided and two of the DC input couplings are coupled via respective copper strips to corresponding power supply input couplings.5. An electric motor controller according to claim 3 or 4, wherein the controller has casing and the power supply input couplings are located in a casing extension.6. A kit comprising at least two electric motor controllers according to any of claims I to 5, wherein the electric motor controllers are configured to be positioned back-to-back with their rear faces facing.7. A kit comprising at least two electric motor controllers according to claim 5, wherein the electric motor controllers are configured to be positioned back-to-back with their rear faces facing one another and the casings of the electric motor controllers are mirror images of one another so that when the controllers are positioned back-to-back, the extensions enable connection of the power supply input couplings of the controllers to a power supply source via conductors passing through the extensions.8. An electric motor-controller assembly comprising an electric motor controller according to claim I or 2 and a motor, the controller and the motor sharing a cooling system.9. A modular motor assembly comprising a plurality of electric motor controllers according to any of claims I to 5 and a respective motor for each electric motor controller, the electric motor controllers and motors being arranged such that adjacent electric motor controllers are positioned back-to-back and share a cooling system of the assembly.10. An assembly according to claim 9, wherein the cooling system comprises at least C\i one of heatsink and a coolant circulation system. 15CO 11. An assembly according to claim 10, wherein the cooling system comprises a cooling manifold extending over the motors and the heat sink. (0C'%J 12. An electric motor-controller assembly comprising one or more controllers according to any of claims I to 5, each for controlling a corresponding motor of the assembly 13. A vehicular electric motor controller according to any of claims I to 5.14. A vehicular electric motor-controller assembly according to any of claims 8 to 12.15. An electric motor controller substantially as hereinbefore described with reference to and/or as illustrated in the accompanying drawings.16. A modular motor-controller assembly substantially as hereinbefore described with reference to and/or as illustrated in the accompanying drawings.17. A vehicle having an electric motor controller according to any of claims I to 5 or or a motor-controller assembly according to any of claims 8 to 12 or 16. c\J r C1) (0 c\J