Abstract: A turbine of a turbocompound engine (10) for extracting energy from the exhaust fluid flow of an and a controller (40) thereof is described. The turbine (10) comprises a housing (30); a turbine wheel (12) rotatably coupled within the housing (30) and rotatable by a fluid flow to provide a rotational output (14); a variable load (34) applying a load to the rotational output; and a controller (40). The controller (40) is configured to: receive information (404) relating to the operating conditions of the turbine (10); calculate an optimum operating velocity (402) of the rotational output based on the operating conditions; and supply a signal (410) to the variable load (34) to vary the load applied to the rotational output (14) in response to said operating conditions so that the rotational output (14) rotates at a corrected operating velocity (408). Such an arrangement increases the ability to operate the turbine at its optimum operating velocity.

Abstract: A turbo-compressor comprises a compressor wheel having an attachment arrangement for attaching the wheel to a drive shaft. The attachment arrangement includes an axially extending spigot internally radially located in a bore in the drive shaft and secured to the drive shaft by fastening means into the rear of the compressor wheel. Thus the compressor wheel expands and tightens into the shaft at speed. Furthermore, the nose of the compressor wheel is free to accept an aerodynamic profile.

Abstract: An electrical controller for electric motors is provided. A control system for an electric motor comprises a supply for supplying excitation current to different windings of the motor at any given time. Furthermore, the amplitude of the excitation current is independently variable of the timing and duration of the application of the excitation current to the windings. This allows increased control of the motor and facilitates the operation of the motor at high mechanical and/or electrical speeds.

Abstract: A forced induction system for an engine comprising a compressor for increasing the pressure of gas into the engine and a turbine arranged to be driven by engine exhaust gas. The system further comprises a generator and an electric motor. The generator is arranged to be driven by the turbine and the motor is arranged to drive the compressor, wherein the generator and motor are electrically connected. The system comprises electrical control means arranged to receive the electrical signal output by said generator during operation and to apply an AC control signal to said electric motor whereby the compressor is driven at least in part by an output torque of the turbine via the electrical connection therebetween.