Abstract: For polyharmonic flux motor loss increase, a method offsets pulse width modulation (PWM) carriers to a motor to increase motor harmonics. The offset PWM carriers increase energy losses for the motor.

Abstract: For polyharmonic flux motor loss increase, a method offsets pulse width modulation (PWM) carriers to a motor to increase motor harmonics. The offset PWM carriers increase energy losses for the motor.

Abstract: This application discloses a routing loop reduction method, an apparatus, and a system. The method includes: a first network device receives a first packet, the first packet carries identifier information and a first route, and the identifier information includes a source device identifier of a device that advertises the first route or a source protocol identifier of a routing protocol to which the first route belongs. The first network device runs a first routing protocol and a second routing protocol, and the first routing protocol is different from the second routing protocol. The first network device determines, based on the identifier information, that advertising the first route to a second network device running the second routing protocol causes a routing loop.

Abstract: A high-strength and high-toughness magnesium alloy includes a Mg—Al—Bi—Sb—Zn—Sr—Y—Mn alloy, prepared from the following components in percentage by mass: 7.0 to 10.0% of Al, 0.2 to 2.0% of Bi, 0.2 to 0.8% of Sb, 0.2 to 0.5% of Zn, 0.1 to 0.5% of Sr, 0.03 to 0.3% of Y, 0.05 to 0.1% of Mn and a balance of Mg.

Abstract: For high frequency injection (HFI) transition disturbance elimination, a processor directs an HFI transition for a motor. The processor determines compensation pulse voltages for an HFI compensation pulse. The processor further injects a sum of the HFI compensation pulse and an HFI voltage into a current regulator voltage output signal for a compensation Pulse Width Modulation (PWM) cycle.

Abstract: For high frequency injection (HFI) transition disturbance elimination, a processor directs an HFI transition for a motor. The processor determines compensation pulse voltages for an HFI compensation pulse. The processor further injects a sum of the HFI compensation pulse and an HFI voltage into a current regulator voltage output signal for a compensation Pulse Width Modulation (PWM) cycle. The HFI compensation pulse settles an HFI current to a steady state.

Abstract: A system may include an inverter configured to convert a direct current (DC) voltage to an alternating current (AC) voltage. The system may also include a control system communicatively coupled to the inverter. The control system may receive a torque current feedback from a motor and may generate, based on the torque current feedback, a command torque current and a command flux current. The control system may generate, based on the command torque current and the command flux current, a command torque voltage and a command flux voltage and may generate, based on a slip frequency and a rotor frequency, a command frequency. The control system may determine one or more operating parameters for the inverter based on the command frequency, the command torque voltage, and the command flux voltage and may control the inverter based on the one or more operating parameters.

Abstract: A system may include an inverter configured to convert a direct current (DC) voltage to an alternating current (AC) voltage. The system may also include a control system communicatively coupled to the inverter. The control system may receive a torque current feedback from a motor and may generate, based on the torque current feedback, a command torque current and a command flux current. The control system may generate, based on the command torque current and the command flux current, a command torque voltage and a command flux voltage and may generate, based on a slip frequency and a rotor frequency, a command frequency. The control system may determine one or more operating parameters for the inverter based on the command frequency, the command torque voltage, and the command flux voltage and may control the inverter based on the one or more operating parameters.

Abstract: A component includes an adaptive estimator. A converter includes a switching rectifier connected to an LCL filter with a converter inductor, a capacitor, and grid inductor connected to a voltage source through a conductor with unknown inductance. Current of the converter inductor is input to the adaptive estimator which includes an ideal LCL filter model that generates, using a simple filter, a desired dynamic behavior of the converter and LCL filter and a disturbance compensator. An LCL steady-state (“SS”) compensation models a steady-state effect of the LCL filter and conductor. Output of the adaptive estimator is subtracted from output of the LCL SS compensation to form a disturbance estimate, which is summed with a feedback loop output of the converter to form a voltage control signal that controls switching of the switching rectifier. The voltage control signal is summed with the disturbance estimate and is input to the adaptive estimator.

Abstract: An active rectifier with a controller including a feedforward component, a modulator and a modulation index controller. The modulator generates switching control signals according to a reference to convert AC input power from the AC input to control the DC bus voltage at the DC output. The feedforward component computes the reference according to an estimated total inductance of the AC input, a grid voltage of the AC input, a modulation index reference, and a reactive power offset signal, and the modulation index controller computes the reactive power offset signal according to an error between the modulation index reference and a feedback modulation index.

Abstract: An active rectifier with a controller including a feedforward component, a modulator and a modulation index controller. The modulator generates switching control signals according to a reference to convert AC input power from the AC input to control the DC bus voltage at the DC output. The feedforward component computes the reference according to an estimated total inductance of the AC input, a grid voltage of the AC input, a modulation index reference, and a reactive power offset signal, and the modulation index controller computes the reactive power offset signal according to an error between the modulation index reference and a feedback modulation index.

Abstract: For counter electromotive force estimation, a disturbance estimator calculates an estimated disturbance as a control function of a quadrature axis current regulator output signal and a quadrature axis current feedback signal of a running permanent magnet motor. A calculator calculates an estimated counter electromotive force of the running permanent magnet motor as a function of the estimated disturbance, a control flux, and an angular velocity.

Abstract: The present application relates to geophysical survey, particularly provides an inversion velocity model, a method for establishing the same and a method for acquiring images of underground structure. The method for establishing inversion velocity model comprises: converting observation seismic records into first intermediary data which contains data with frequency no higher than a first predetermined frequency; calculating synthetic seismic records based on a set initial velocity model and converting the synthetic seismic records into second intermediary data which also contains data with frequency no higher than the first predetermined frequency; establishing an objective function based on the first intermediary data and the second intermediary data; calculating a velocity gradient of seismic wave based on the objective function; calculating a iteration step of the velocity gradient; determining the inversion velocity model based on the velocity gradient and the iteration step.

Abstract: For predicting a load pattern, a method determines a torque error from a torque reference modified by a low pass filter function of the torque reference. The torque reference is one of measured from an induction machine energized by a flux current and a torque current and calculated in an induction machine controller. The method determines a torque increase pulse in response to a torque relative variation calculated from the torque error exceeding an increase threshold. In response to detecting the torque increase pulse, the method determines a change delay time from the torque relative variation and the torque increase pulse. The method further determines a change period from at least two torque increase pulses. The method increases the flux current before a change time that is predicted as a function of the change delay time and the change period.

Abstract: A high-strength and high-toughness magnesium alloy includes a Mg—Al—Bi—Sb—Zn—Sr—Y—Mn alloy, prepared from the following components in percentage by mass: 7.0 to 10.0% of Al, 0.2 to 2.0% of Bi, 0.2 to 0.8% of Sb, 0.2 to 0.5% of Zn, 0.1 to 0.5% of Sr, 0.03 to 0.3% of Y, 0.05 to 0.1% of Mn and a balance of Mg.

Abstract: An active rectifier with a controller including a feedforward component, a modulator and a modulation index controller. The modulator generates switching control signals according to a reference to convert AC input power from the AC input to control the DC bus voltage at the DC output. The feedforward component computes the reference according to an estimated total inductance of the AC input, a grid voltage of the AC input, a modulation index reference, and a reactive power offset signal, and the modulation index controller computes the reactive power offset signal according to an error between the modulation index reference and a feedback modulation index.

Abstract: The invention provides a method of refining aluminum alloy, which is characterized in that aluminum-based nanometer quasicrystal alloy is used as an aluminum alloy refiner to refine the aluminum alloy; the aluminum-based nanometer quasicrystal alloy does not comprise Si, Fe or Cr; the aluminum-based nanometer quasicrystal alloy consists of (1) Al; (2) Mn and (3) La and/or Ce. The refiner selected in the invention is rare earth-containing alloy which has a strong refinement ability on the aluminum alloy, and is nanometer quasicrystal; after adding the rare earth-containing alloy to melt, the element distribution of the rare earth-containing alloy is more uniform than that of traditional alloy; and nanometer quasicrystal particles substantially increase the number of heterogeneous nucleation particles and improve the grain refinement effect of the aluminum alloy.

Abstract: For flux vector control, a controller generates a control signal for a permanent magnet machine. The controller further generates an output voltage angle as a function of the control signal that regulates the permanent magnet machine. The output voltage angle includes an angular canceling function that cancels an angular control portion of a dynamic response of the permanent magnet machine such that the control signal controls the permanent magnet machine as a second-order quadrant-axis current.

Abstract: The present application relates to geophysical survey, particularly provides an inversion velocity model, a method for establishing the same and a method for acquiring images of underground structure. The method for establishing inversion velocity model comprises: converting observation seismic records into first intermediary data which contains data with frequency no higher than a first predetermined frequency; calculating synthetic seismic records based on a set initial velocity model and converting the synthetic seismic records into second intermediary data which also contains data with frequency no higher than the first predetermined frequency; establishing an objective function based on the first intermediary data and the second intermediary data; calculating a velocity gradient of seismic wave based on the objective function; calculating a iteration step of the velocity gradient; determining the inversion velocity model based on the velocity gradient and the iteration step.

Abstract: For voltage angle control, a control module generates a control signal for a grid. A canceling function generates an output voltage angle as a function of the control signal that regulates the grid. The output voltage signal includes an angular canceling function that cancels an angular control portion of a dynamic response of the grid such that the control signal controls the grid as a second-order quadrant-axis current.