9 results about "Stationary Reference Frame" patented technology

A data communication method for a de-icing system for a turbine engine is disclosed. The turbine engine includes a fixed reference frame and a rotating reference frame. The system includes a non-contact rotating power transformer (RTU), the primary side of which is constrained by the fixed reference frame, and the secondary side of which is constrained by the rotating reference frame. The fixed reference frame includes an ice protection and control unit (IPC) and a power supply device (DC / AC) for supplying AC power to the primary side. The IPC transmits commands to the DC / AC to adjust the level of power supplied to the primary side. The rotating reference frame includes a propeller (1) and a switch, with a plurality of resistors fixed to the propeller. The switch is used to sequentially distribute the power supplied to the secondary side to the resistors. The protection and control unit (IPC) is programmed to transmit switching commands to the switch via the power supply unit (DC / AC) and the transformer (RTU) by issuing instructions (Ic1, Ic2, Ic3, Ic4, Ic5, Intl) to the power supply unit (DC / AC) to encode the voltage wave sequence (To) applied to the primary side. The switch is programmed to decode the voltage wave sequence (To) recovered on the secondary side.

A method of driving a multi-phase permanent magnet rotor motor having a plurality of phase coils. The method comprises outputting pulse modulated control signals to the respective phase coils to bring the motor to a constant mode of operation. Once the motor is in its constant mode of operation, the method includes measuring phase coil currents and, for a selected phase coil, adjusting values of multi-phase stationary reference frame voltages for only remaining phase coils by one or more predetermined increments until the phase coil currents of the remaining phase coils equals the phase coil current of the selected phase coil or until the phase coil currents of the remaining phase coils fall with a predetermined range with respect to the phase coil current of the selected phase coil.

Power conversion systems and methods are provided that use a four-leg power converter and delta-sigma control. Each of the four phase legs includes an LC filter and power switching elements. A control system determines an electrical operational characteristic for each of the four phase legs and generates control reference targets in a stationary reference frame for each phase leg based on the electrical operational characteristics and a rotational reference frame. The rotational reference frame includes a direct axis (d-axis) component, a quadrature axis (q-axis) component, a delta axis (δ-axis) component, and a sigma axis (σ-axis) component. The delta axis component indicates a difference between a common mode and a neutral electrical characteristic, and the sigma axis component indicates a sum of the common mode and the neutral electrical characteristic. The control system drives the power switching elements of the four phase legs in accordance with the control reference targets.

This invention proposes a sensorless multi-vector predictive control method and system for permanent magnet synchronous motors (PMSMs), belonging to the field of measurement and predictive control technology for PMSMs. The method includes: obtaining a current prediction equation based on the discrete-domain voltage response equation of the motor; approximating a reference voltage vector using two adjacent commutation vectors and assigning them respective application times, designated as the first application time and the second application time; constructing a quadratic cost function and solving for the optimal application time; defining the injected high-frequency voltage signal, obtaining the injected signal representation in the stationary reference frame, determining the sector where the injected signal is located, and determining the application times of two adjacent vectors within that sector; obtaining the generated high-frequency current response representation after the voltage signal is injected, and obtaining the rotor position error based on the high-frequency current response representation; and using coherent demodulation technology to extract the observation error.

Various examples are provided related to fault detection of power converters. In one example, a method includes sensing phase currents of a three-phase transformer; determining a centroid vector in an alpha-beta stationary reference frame based upon averaged values of the sensed phase currents; identifying a fault on a side of the transformer based upon a location of the centroid vector within the alpha-beta stationary reference frame, the location defined by a magnitude and an angle of the centroid vector; and adjusting operation of the power converter in response to the identified fault. In another example, a power converter includes a three-phase transformer connected between primary and secondary side three-phase bridges and control circuitry that can determine a centroid vector based upon sensed phase currents; identify a fault on a side of the three-phase transformer; and adjust operation of the power converter in response to the identified fault.

The invention discloses a non-contact dynamic weighing system and method based on magnetic sensing, the system comprises a bearing unit, an elastic deformation unit, a magnetic field generation unit, a magnetic sensing array unit and a signal processing and control unit, the bearing unit is used for contacting with a measured object and bearing the load of the measured object; the elastic deformation unit is connected between the bearing unit and an external static reference frame; and the magnetic field generating unit is fixed on a component which moves along with the bearing unit and is used for generating a stable magnetic field. According to the non-contact dynamic weighing system and method based on magnetic sensing disclosed by the invention, the problems that the existing dynamic weighing technology is easily interfered by the environment, the service life of a sensor is short, the installation and maintenance cost is high, the measurement precision is low and the anti-interference capability is poor are solved, non-contact dynamic weighing is realized, and the stability, repeatability and intelligent level of the weighing system are improved.

The invention provides a permanent magnet synchronous motor position-sensing-free multi-vector predictive control method and system, and belongs to the technical field of permanent magnet synchronous motor measurement predictive control, and the method comprises the steps: obtaining a current predictive equation based on a motor discrete domain voltage response equation; approximating a reference voltage vector by using two adjacent commutation vectors, and respectively endowing the reference voltage vector with action time, namely a first action time and a second action time; constructing a quadratic form cost function and solving the quadratic form cost function to obtain the optimal action time; an injected high-frequency voltage signal is defined, injection signal representation in the static reference system is obtained, then a sector where the injection signal is located is obtained, and action time of two adjacent vectors in the sector is determined; after the voltage signal is injected, the generated high-frequency current response representable is obtained, and a rotor position error is obtained based on the high-frequency current response representable; and the observation error is extracted by adopting a coherent demodulation technology.

A method, an elevator (100), and an electric converter unit (14) for determining the rotor position of an electric motor (12) are proposed. The method includes: supplying (41) a first excitation signal (ES1) to the electric motor (12); determining (42) a first response signal (RS1) generated in the electric motor (12) in response to the first excitation signal (ES1); determining (43) an electrical angle of the direct axis (D, -D, +D) of the motor (12) relative to a stationary reference frame based on the first response signal (RS1); supplying (44) a second excitation signal (ES2) to the motor (12), wherein the second excitation signal (ES2) is based on the determined electrical angle; determining (45) a second response signal (RS2) generated in the motor (12) in response to the second excitation signal (ES2); and determining (46) the rotor position based on the second response signal (RS2).

A wind turbine comprising a hydraulic system having a hydraulic fluid supply system located in a stationary reference frame, and a hydraulic fluid using system located in a rotary reference frame. A rotary union module is provided for conveying hydraulic fluid between the stationary reference frame and the rotating reference frame. The rotary union module comprises: a rotary union module having a stationary component providing a stationary hydraulic coupling in communication with the hydraulic fluid supply system, and a rotatable component providing a rotatable hydraulic coupling communicating with the hydraulic fluid using system. An adapter is provided which is configured to join to the rotary union module at the rotatable component. The adapter comprises a module-side coupling configured to interface with the rotatable hydraulic coupling of the rotary union module and a pipe-side coupling configured to interface with at least a first hydraulic pipe, wherein the adapter is provided with a first conduit extending between the pipe-side coupling and the module-side coupling, and wherein the adapter further comprises a drain passage that extends from a tapping point at the first conduit. The drain passage may be configured to lead to a low-pressure drain area such as a tank or low-pressure side of a fluid pump.