59results about How to "Ensure system stability" patented technology

While a PWM-controlled, FET-switched three-phase motor is operating in a mechanical damping mode, a single current sensor is used to measure current in the motor. When mechanical feedback into the motor exceeds a predetermined threshold, a bank of the FET switches can be closed to provide damping of the mechanical feedback. This causes currents to circulate within the motor, which an external single current sensor cannot measure to determine current load or when the mechanical feedback is no longer a problem. The present invention periodically switches selected switches necessary to sample the current in at least one phase of the motor to determine when the mechanical feedback into the motor is no longer a problem, while preferably also maintaining an average zero voltage vector.

A lithographic apparatus including a position control system to control a position of a moveable object is presented, The position control system includes a position controller, an object represented as an object filter, a position feedback circuit, and an acceleration control system. The acceleration control system includes a subtractor and a first filter in a first circuit branch and a second filter in a second circuit branch. A position controller signal output from the position controller is input into the subtractor of the acceleration control system. An external disturbance force, however, is directly exerted upon the object. Thus, a first transfer function from the input of the subtractor to the acceleration of the object for the position controller force may be different than a second transfer function from the input of the object to the acceleration of the object for the disturbance force. Preferably, the first transfer function is identical to a transfer function for the position controller force in case no acceleration control system is present in the position control system.

An evaporation cycle heat exchange system for a vehicle is provided. The evaporation cycle heat exchange system is a new type of cooling system that cools vehicle electronic components, a fuel cell stack, an internal combustion engine, an automatic transmission, a turbocharger, etc. using an evaporative heat exchanger, thus improving cooling efficiency and reducing the size of components such as a radiator. The evaporation cycle heat exchange system cools coolant circulating through a vehicle cooling system by employing an evaporative heat exchanger in which a working fluid flows by a pressure difference caused by volume expansion and capillary phenomenon. Accordingly, it is possible to improve the cooling efficiency of the entire cooling system, reduce the size of components to comply with pedestrian protection regulations, improve fuel efficiency, and ensure the stability of the system. Moreover, the present invention provides an evaporation cycle heat exchange system for a vehicle, in which a product-integrated or line-integrated evaporative heat exchanger capable of being mounted in various vehicle components such as an inverter, a fuel cell stack, an oil fan of an internal combustion engine, a turbocharger, an automatic transmission oil fan, etc. is employed. Accordingly, it is possible to easily apply the evaporative heat exchanger to various vehicle components and various vehicle models, and thus it is possible to increase the degree of freedom of the design of the cooling system.

In a method and device for controlling a hydraulic drive system, in particular in a crane or construction machine, a closed hydraulic circuit has a hydraulic pump and motor in which depending upon a desired value (ndes) of an output parameter of the hydraulic circuit, an actuating signal (I) is generated for adjusting the hydraulic pump and / or motor. The actuating signal (I) is limited and / or reduced by a superordinate control module (6) depending on matching of a specified power value (P+; P−) with a current power value (PPu; PM) of the hydraulic pump and / or motor.

The wind-wave complementary energy integrated system based on fixed foundation and generation and transmission method thereof pertains to the field of ocean renewable energy utilization, solving the problem of combining the wind and wave energy in a support structure, including a wind turbine, a tower, a wave energy device and a single pile foundation, the wind turbine is connected to the tower, and the single pile foundation is at the bottom of the tower, the single pile foundation is connected to the seabed, and the wave energy device is mounted on the tower near the sea surface. The effect is the renewable energy utilization rate and the energy conversion rate are effectively improved, thus reducing the cost to a certain extent and having high utility.