An electric rotating machine having a stator and a rotor, wherein the rotor is provided with rotor windings connected to electric contacts to carry a field current. A control device is provided to adjust the field current carried by the rotor windings. At least one sensor is provided to give information about the temperature at the location of the at least one sensor. The at least one sensor is located on or embedded in the rotor windings, and the at least one sensor is connected to the control device such that the control device is able to read the information given by the at least one sensor. The control device is further arranged to adjust the field current carried by the rotor windings and/or power output or power input of the electric rotating machine based on the information given by the at least one sensor.

An electrical generator (114) and a power electronics interface (115) for a direct-drive turbine (110). The turbine (110) may include a rotor (112) for transforming kinetic (from, e.g., wind, water, steam) into mechanical energy, the generator (114) for transforming the mechanical into electrical energy, and the power electronics interface (115) for conditioning the electrical energy for delivery to a power distribution grid (124). The interface (115) includes a three-phase single-stage boost inverter (120) for converting a lower DC voltage into a higher AC voltage, and which uses a synchronous reactance of the generator (114) as a DC-link inductance. The turbine (110) has neither the gearbox of indirect-drive designs nor the electrolytic capacitor bank of conventional direct-drive designs, while still allowing for a substantially smaller number of generator poles, resulting in reduced size, weight, complexity, and cost.

Installation for converting hydraulic energy into electrical energy, provided with a fixed speed hydraulic machine comprising a pump-turbine (2) linked to a generator (20) by a shaft.

The installation further comprises: an electrical torque actuator (34) to establish a circuit with the generator (20), electrical torque actuator connection means (35) for connecting the generator (20) the electrical torque actuator, and command means (29) for detecting a disconnection of the generator (20) from the grid, and for commanding the electrical torque actuator connection means (35) to connect the generator (20) to the electrical torque actuator (34).

A system and method of operating a pumped storage power plant using a double fed induction machine with a frequency converter in a rotor circuit is disclosed. A current target value for the rotor current frequency is determined based on a target power to be transmitted between an electrical grid and the double fed induction machine depending on measured actual operating variables. A current inadmissible synchronous deadband is determined depending on variables characterizing a current state of the pumped storage power plant. The synchronous deadband is determined by a permissible minimum required rotor current frequency or speed difference of the rotor speed from the synchronous speed for the stationary operation. The converter is controlled to generate voltages and currents with the current target value of the rotor current frequency if the current target value of the rotor current frequency or speed does not fall in the current inadmissible synchronous deadband.

A variable speed pumping system includes a generator motor including a frequency converter, in which the variable speed pumping system, in the pumping mode, supply a power command to the generator motor to perform power control, and the power control correction signal generator adds a value obtained by multiplying a signal based on a difference between the power input command and an actual power input measured by a power detector in the pumping mode by a constant gain to a signal based on the deviation and inputs the added value to an integration control element to generate the power control correction signal based on an output signal of the integration control element.

A hydroelectric power generation system is included in a channel control system. The channel control system includes a command section that outputs a command value of a flow rate or pressure of a fluid, an opening degree control unit that calculates a target opening degree based on the command value, and a motor-operated valve installed in a channel through which the fluid flows. The valve opens and closes in accordance with the target opening degree. The hydroelectric power generation system includes a water turbine disposed in the channel, a generator driven by the water turbine, and a generator control unit that controls at least one of a torque and a number of rotations of the generator based on opening degree information that indicates a measured value of an actual opening degree of the valve or an opening degree estimated.

This method for stabilizing the rotation speed of a hydraulic machine having S-characteristic and comprising a distributor (9) is adapted to modify a water flow, so that the machine can be coupled to a grid. The method comprises the steps of calculating an orientation of the distributor (9); and orienting the distributor according to the calculated orientation. The method further comprises the steps of providing an electric torque to the machine so as to reach a target speed.

A hydroelectric power generation system includes: a generator driven by the hydraulic turbine; a head adjuster adjusting an effective head of the hydraulic turbine; and a controller cooperatively executing: flow rate control for controlling the generator such that a flow rate in the hydraulic turbine is brought close to a target flow rate; and head adjusting control for adjusting the effective head of the hydraulic turbine using the head adjuster such that the effective head of the hydraulic turbine falls within a first range.

A variable-speed pumped storage power generation apparatus sets a maximum change rate of a power output command constant when a slip frequency is within a normal operating range, limits the maximum change rate of the power output command by multiplying the maximum change rate by a value in a range of one to zero when the slip frequency is within a range falling below a lower limit of the normal operating range by a predetermined value or less or within a range exceeding an upper limit of the normal operating range by a predetermined value or less, and limits the maximum change rate of the power output command by multiplying the maximum change rate by zero when the slip frequency is in a range falling below the lower limit by the predetermined value or more or in a range exceeding the upper limit by the predetermined value or more.

A control device performs a control process including the steps of: determining whether a predetermined condition has been established; when it has been determined that the predetermined condition has been established, clearing a counter; performing reverse rotation control; performing forward rotation control; incrementing the counter; and determining whether the counter's counted value has reached an upper limit.