Vehicle, control device and method for controlling oil supply to electrical machine

A method, performed by a control device, for controlling an oil system of a vehicle to oil to an electrical machine and a transmission of a vehicle powertrain of the vehicle, the oil system comprising:

• a mechanical pump configured to transfer oil to a first supply conduit of the oil system, wherein a speed of the mechanical pump being dependent of a rotational speed of the electrical machine;
• a second supply conduit configured to supply oil to the transmission, the second supply conduit fluidly connected to the first supply conduit at a downstream end of the first supply conduit;
• a third supply conduit configured to supply oil to the electrical machine, the third supply conduit fluidly connected to the first supply conduit at the downstream end of the first supply conduit;
• and a controllable valve configured to control an amount of oil supplied to the electrical machine via the third supply conduit through control of oil pressure distribution between the second supply conduit and the third supply conduit,
• the method comprising:
• in response to a determination that a predetermined criterion is fulfilled, controlling the controllable valve to an at least partially throttled position, unless the controllable valve is already in said position,
• wherein the predetermined criterion is that:
• the oil temperature at the downstream end of the first supply conduit is above a predetermined temperature threshold;
• the electrical machine is operated above an upper power threshold;
• and
• the rotational speed of the electrical machine is within a predetermined rotational speed interval, said predetermined rotational speed interval being defined by a lower rotational speed threshold and an upper rotational speed threshold.

A computer program product stored on a non-transitory computer-readable medium, said computer program product for controlling an oil system of a vehicle to supply oil to an electrical machine and a transmission of a vehicle powertrain of the vehicle, the oil system comprising:

• a mechanical pump configured to transfer oil to a first supply conduit of the oil system, wherein a speed of the mechanical pump being dependent of a rotational speed of the electrical machine;
• a second supply conduit configured to supply oil to the transmission, the second supply conduit fluidly connected to the first supply conduit at a downstream end of the first supply conduit;
• a third supply conduit configured to supply oil to the electrical machine, the third supply conduit fluidly connected to the first supply conduit at the downstream end of the first supply conduit;
• and a controllable valve configured to control an amount of oil supplied to the electrical machine via the third supply conduit through control of oil pressure distribution between the second supply conduit and the third supply conduit,
• wherein said computer program product comprising computer instructions to cause one or more control devices to perform the following operations:
• in response to a determination that a predetermined criterion is fulfilled, control the controllable valve to an at least partially throttled position, unless the controllable valve is already in said position,
• wherein the predetermined criterion is that:
• the oil temperature at the downstream end of the first supply conduit is above a predetermined temperature threshold;
• the electrical machine is operated above an upper power threshold;
• and
• the rotational speed of the electrical machine is within a predetermined rotational speed interval, said predetermined rotational speed interval being defined by a lower rotational speed threshold and an upper rotational speed threshold.

A control device configured to control an oil system of a vehicle to supply oil to an electrical machine and a transmission of a vehicle powertrain of the vehicle, the oil system comprising:

• a mechanical pump configured to transfer oil to a first supply conduit of the oil system, wherein a speed of the mechanical pump being dependent of a rotational speed of the electrical machine;
• a second supply conduit configured to supply oil to the transmission, the second supply conduit fluidly connected to the first supply conduit at a downstream end of the first supply conduit;
• a third supply conduit configured to supply oil to the electrical machine, the third supply conduit fluidly connected to the first supply conduit at the downstream end of the first supply conduit;
• and a controllable valve configured to control an amount of oil supplied to the electrical machine via the third supply conduit through control of oil pressure distribution between the second supply conduit and the third supply conduit,
• wherein the control device is configured to:
• in response to a determination that a predetermined criterion is fulfilled, control the controllable valve to an at least partially throttled position, unless the controllable valve is already in said position,
• wherein the predetermined criterion is that:
• the oil temperature at the downstream end of the first supply conduit is above a predetermined temperature threshold;
• the electrical machine is operated above an upper power threshold;
• and
• the rotational speed of the electrical machine is within a predetermined rotational speed interval, said predetermined rotational speed interval being defined by a lower rotational speed threshold and an upper rotational speed threshold.