A power generation system for a drilling tool includes a turbine, an alternator, a converter and a first active rectifier control (ARC). The turbine is adapted to be driven by a fluid flow in a well. The alternator is coupled to the turbine and generates an alternative current (AC). The converter converts the AC to direct current (DC) and carries out active rectification. The first active rectifier control (ARC) controls the active rectification of the converter.

A method of compensating for rotor position error of a rotor of a permanent magnet synchronous generator (PMG) that provides electrical power to a direct current (DC) power generating system, the method including obtaining PMG phase voltages and resolver processed angular position output when the PMG is driven by a prime mover. Once obtained, a PMG fundamental phase voltage waveform is selected by eliminating higher order harmonics. A mechanical angle of the rotor is then converted into an electrical angle, then the electrical angle is aligned within the mechanical angle with a corresponding PMG fundamental phase voltage angle by adjusting offset to the electrical angle. After alignment, a plurality of resolver error offset values associated with the electrical angle are stored and additional values to the compensation table are added by interpolating data between two corresponding resolver error offset values of the plurality of resolver error offset values.

An electric machine includes a stator, a rotor, and magnets. The stator includes multiple flux members having ferrous material. The rotor is configured to rotate relative to the stator and spaced from the stator by an air gap. The magnets are rigidly mounted to the flux members of the stator. At least a first magnet and a second magnet of the magnets includes an elongated axis parallel to a radius of the rotor and a minor axis perpendicular to the elongated axis, and a first pole of the first magnet having a first polarity and positioned along the minor axis to face a first pole of the second magnet having the first polarity.

A power generation system for a drilling tool includes a turbine, an alternator, a converter and a first active rectifier control (ARC). The turbine is adapted to be driven by a fluid flow in a well. The alternator is coupled to the turbine and generates an alternative current (AC). The converter converts the AC to direct current (DC) and carries out active rectification. The first active rectifier control (ARC) controls the active rectification of the converter.

Provided are: a starter generator including a field portion having a permanent magnet, and an armature unit including a first multi-phase winding and a second multi-phase winding which are arranged in parallel; a first power conversion unit including a first positive-side DC terminal connected to a battery and a plurality of first AC terminals connected to the first multi-phase winding, the first power conversion unit being configured to convert a power bidirectionally between DC and AC; a second power conversion unit including a plurality of second AC terminals connected to the second multi-phase winding, the second power conversion unit being configured to control a current to be input and output via the second AC terminals; and a control unit configured to detect a positional relationship between the field portion and the armature unit based on an output voltage of the second multi-phase winding, and control the first power conversion unit and the second power conversion unit in accordance with the detected positional relationship.

In one embodiment, a generator includes a rotor configured to rotate in cooperation with a stator to generate electrical power. An exciter of the generator includes at least one circuit board, a stationary exciter stator, and a control circuit. The circuit board is mechanically coupled to a rotor of the generator and includes at least one coil of an electrical conductor. The stationary exciter stator is configured to induce a current in the at least one coil of the at least one circuit board. The control circuit is configured to modify the current from the at least one coil and provide the modified current to a field of the generator.

A method for reducing a delay between a power command and actual power of a power system includes receiving, via a power angle estimator, a power command of the power system. The method also includes receiving, via the power angle estimator, one or more grid conditions of the power grid. Further, the method includes estimating, via the power angle estimator, a power angle signal across the power system based on the power command and the one or more grid conditions. Moreover, the method includes receiving, via a phase locked loop (PLL), the estimated power angle signal. In addition, the method includes generating, via the PLL, a PLL phase angle signal based, at least in part, on the estimated power angle signal. Thus, the method further includes controlling, via a converter controller, a power conversion assembly of the power system based on the PLL phase angle signal.

In one embodiment, a generator includes a rotor configured to rotate in cooperation with a stator to generate electrical power. An exciter of the generator includes at least one circuit board, a stationary exciter stator, and a control circuit. The circuit board is mechanically coupled to a rotor of the generator and includes at least one coil of an electrical conductor. The stationary exciter stator is configured to induce a current in the at least one coil of the at least one circuit board. The control circuit is configured to modify the current from the at least one coil and provide the modified current to a field of the generator.

A starting power generation apparatus according to an embodiment of the present invention includes: a starter generator including a field portion having a permanent magnet, and an armature unit including a first multi-phase winding and a second multi-phase winding which are arranged in parallel; a first power conversion unit including a first positive-side DC terminal connected to a battery and a plurality of first AC terminals connected to the first multi-phase winding, the first power conversion unit being configured to convert a power bidirectionally between DC and AC; a second power conversion unit including a plurality of second AC terminals connected to the second multi-phase winding, the second power conversion unit being configured to control a current to be input and output via the second AC terminals; and a control unit configured to detect a positional relationship between the field portion and the armature unit based on an output voltage of the second multi-phase winding, and control the first power conversion unit and the second power conversion unit in accordance with the positional relationship detected. The control unit is configured to detect the positional relationship when the starter generator is stopped, based on time widths of two or more predetermined voltages generated in two or more windings constituting the second multi-phase winding in a case that an output voltage of the battery is applied to the first multi-phase winding for a predetermined time in a state where current input and output via the second AC terminals is off.

According to one embodiment, a power generation system includes a power generator, a displacement measuring part, and a converter. The power generator includes a movable part and converts mechanical energy of the movable part into electric power. The displacement measuring part measures a displacement of the movable part. The converter includes a switching circuit whose duty ratio is controlled based on the measured displacement, and converts a voltage level of the electric power.