Hydraulic supply system

A hydraulic supply system comprising:

• a first oil pump;
• a second oil pump of which an operation status is controllable;
• a pressure regulating valve configured to regulate a line pressure by opening a drain port to reduce a hydraulic pressure of hydraulic fluid, discharged from the first oil pump and the second oil pump, in accordance with a hydraulic pressure command value;
• and
• a controller configured to control the operation status of the second oil pump, control a pressure regulating operation of the pressure regulating valve by setting the hydraulic pressure command value, and adjust a torque capacity of a hydraulic engagement device by using the line pressure as a source pressure, wherein
• the controller is configured to set the hydraulic pressure command value to a value for a required transmission torque of the hydraulic engagement device, and is configured to start an operation of the second oil pump from when a decrease in discharge flow rate of the first oil pump is predicted or when a decrease in the discharge flow rate of the first oil pump is detected and control the pressure regulating valve such that the pressure regulating valve operates to close the drain port by, after a lapse of a predetermined period of time, with which the line pressure becomes lower than a predetermined pressure, from when the operation of the second oil pump is started, temporarily setting the hydraulic pressure command value to a value higher than the value for the required transmission torque.