Fluid turbine modular electric generator including removable stator modules with integrated power electronics and magnetic bearing system
An electric power generation system may be constructed of multiple similar generator modules arranged between a rotor and a stator. The rotor may be coupled to and/or integrated with a turbine that is configured to rotate in the presence of a fluid stream such as wind or water. Each generator module may have a rotor portion configured to generate a magnetic field having at least one characteristic that changes with respect to the rotational speed of the rotor. Each generator module may further have a stator portion configured to generate an alternating electric current responsive to the magnetic field. The generated electric current may be controlled by the stator portion of the generator module in order to magnetically control the rotational speed of the rotor and the turbine. Separation between the rotor and stator portions of the generator module may be magnetically maintained.
1. An electric power generation system, comprising:
a turbine configured to rotate, a rotational speed of the turbine based at least in part on a flow rate of a fluid flow;
a plurality of rotor modules connectively coupled with the turbine via a rotor frame, and collectively configured to generate a magnetic field having at least one characteristic based at least in part on the rotational speed of the turbine; and
a plurality of stator modules configured to:
generate at least one alternating electric current, in response to at least the magnetic field generated by the plurality of rotor modules;
maintain a relative position of the plurality of rotor modules with respect to the plurality of stator modules with magnetic force; and
control the rotational speed of the turbine;
wherein each of the plurality of stator modules is removably coupled with a stator frame and comprises:
at least one generating coil configured to generate the alternating electric current in response to the magnetic field generated by the rotor modules; and
a power electronics module configured to manage the generated alternating electric current and produce a desired magnetically-induced torque that at least partially controls the rotational speed of the turbine, the power electronics module comprising:
an active rectifier;
an inverter; and
a controller comprising a rectifier controller configured to control the active rectifier and an inverter controller configured to control the inverter, the controller configured to:
receive command messages from a data bus;
translate the received command messages into signals for the rectifier controller and signals for the inverter controller; and
control the active rectifier and the inverter in accordance with the received command messages.
2. An electric power generation system in accordance with claim 1 , wherein controlling the rotational speed of the turbine further comprises controlling at least one characteristic of said at least one alternating electric current generated by the plurality of stator modules.
3. An electric power generation system in accordance with claim 2 , wherein controlling said at least one characteristic of said at least one alternating electric current comprises modifying said at least one characteristic with the active rectifier of a corresponding one of the power electronic modules.
4. An electric power generation system in accordance with claim 1 , further comprising a system control module configured at least to coordinate individual stator module participation with respect to control of for controlling the rotational speed of the turbine.
5. An electric power generation system in accordance with claim 1 , wherein the at least one generating coil of each of the plurality of stator modules comprises a generator coil with a plurality of tap points that are dynamically selectable with switches.
6. An electric power generation system in accordance with claim 1 , wherein each of the plurality of rotor modules comprises a permanent magnet fastened to a frame of the rotor module with a flexible coupling that allows movement of the permanent magnet with respect to the frame in a direction parallel to a main magnetic flux path.
7. An electric power generation system in accordance with claim 1 , wherein each rotor module comprises at least one stabilization magnet, each stator module comprises at least one corresponding stabilization magnet, and the stabilization magnets act collectively to keep stable a separation between the plurality of rotor modules and the plurality of stator modules.