A system control apparatus includes a proportional-integral-derivative (PID) controller configured to control a behavior of a system and having a gain, and a gain determiner configured to apply, to a set adaptive load model, a variable associated with an error that varies based on a load change of the system and adaptively vary the gain using the adaptive load model to which the variable associated with the error is applied.

A method for recording the magnitude and phase of electrical voltage in an electrical three-phase supply network for a fundamental and at least one harmonic is provided. The method includes measuring an electrical three-phase voltage of the supply network, transforming the measured voltage values into polar coordinates using a rotating voltage phasor for the fundamental as a measured reference phasor, and respectively observing values of at least one voltage phasor for the fundamental and of at least one voltage phasor for at least one harmonic to be recorded with the aid of a state observer, and tracking the observed values on the basis of the measured reference phasor.

A control logic firmware is received at a power supply unit. The firmware specifies a configuration selected to place a magnitude of an impedance of the power supply unit above a magnitude of an impedance of a network data center power system. The control logic firmware is executed using a power factor correction circuit of the power supply unit including by setting a voltage loop phase margin of the power factor correction circuit to maintain the magnitude of the impedance of the power supply unit above the magnitude of the impedance of the network data center power system.

A DC/DC converter system includes a bidirectional DC/DC converter converting between voltage levels at first and second ports and a control system for controlling the DC/DC converter. The bidirectional DC/DC converter includes a first conversion stage connected to the first port and a second conversion stage interfaced with the first conversion stage and connected to the second port. The control system includes outer and inner control loops. The outer control loop compares a command for one of a voltage level, a current level or power at one of the first and second ports to an actual value of voltage level, current level or power level and outputs an interface current command based on the comparison. The inner control loop compares the interface current command to an actual interface current at an interface of the first and second conversion stages, and controls a switching signal duty value based on the comparison.

A method and apparatus for damping stick-slip oscillations in a drill string. In one embodiment a method includes damping the stick-slip oscillations using a drilling mechanism at the top of said drill string. The speed of rotation of the drilling mechanism is controlled using a PI controller. The control is characterized by tuning the PI controller so that the drilling mechanism absorbs most torsional energy from the drill string at a frequency that is at or near a frequency of the stick-slip oscillations.

A power supply unit for an aerosol generation device includes: a power supply configured to supply power to a heater configured to heat an aerosol source; a receptacle configured to receive power for charging the power supply from a plug connected to an external power supply; a charger configured to control charging of the power supply by power received by the receptacle; and a controller. The receptacle and the power supply are connected in parallel with the charger, and the charger is configured to supply power from the receptacle and the power supply to the controller via the charger.

A DC/DC converter system includes a bidirectional DC/DC converter converting between voltage levels at first and second ports and a control system for controlling the DC/DC converter. The bidirectional DC/DC converter includes a first conversion stage connected to the first port and a second conversion stage interfaced with the first conversion stage and connected to the second port. The control system includes outer and inner control loops. The outer control loop compares a command for one of a voltage level, a current level or power at one of the first and second ports to an actual value of voltage level, current level or power level and outputs an interface current command based on the comparison. The inner control loop compares the interface current command to an actual interface current at an interface of the first and second conversion stages, and controls a switching signal duty value based on the comparison.

A power supply unit for an aerosol generation device includes: a power supply configured to supply power to a heater configured to heat an aerosol source; a receptacle configured to receive power for charging the power supply from a plug connected to an external power supply; a charger configured to control charging of the power supply by power received by the receptacle; and a controller. The receptacle and the power supply are connected in parallel with the charger, and the charger is configured to supply power from the receptacle and the power supply to the controller via the charger.

A method for recording the magnitude and phase of the electrical voltage in an electrical three-phase supply network for a fundamental and at least one harmonic is provided. The method includes measuring an electrical three-phase voltage of the supply network, transforming the measured voltage values into polar coordinates using a rotating voltage phasor for the fundamental as a measured reference phasor, and respectively observing values of at least one voltage phasor for the fundamental and of at least one voltage phasor for at least one harmonic to be recorded with the aid of a state observer, and tracking the observed values on the basis of the measured reference phasor.

A control device, by which a user causes a servo motor to perform desired operation without being conscious of a maximum torque of the servo motor while easily understanding the transmission characteristic, selects which one of sliding mode control and PID control is adopted to control a servo motor based on at least one of a position deviation and a velocity deviation.