Stationary energy generation plant having a control device and method for controlling the same
A stationary energy generation plant includes a control device that serves to control current and energy flow. The energy generation plant includes at least one mechanically driven rotor and a generator mechanically coupled to the rotor. To this end, power electronics operationally connected to the generator enable variable energy flow from the rotor through the generator and the power electronics to a load. In order to compensate for vibrational loads on the generator side, at least one current control is made possible by means of a first intermediate circuit storage of the power electronics. In order to compensate for mechanical vibrational loads and transients of a drivetrain, an energy flow control is provided by means of at least one additional second intermediate circuit storage disposed in the power electronics and having a multiple of the storage capacity of the first intermediate circuit storage.
1. A method for controlling an energy generation plant, comprising
arrangement of position sensors in a drive train of the energy generation plant, which energy generation plant has at least one mechanical rotor, a drive shaft, a step-up transmission, a generator with a rotor/stator unit and power electronics;
detection of rotation angle differences by the position sensors;
monitoring the rotation angle increase of the step-up transmission and the overall twisting of the drive train;
parallel simulation by an equation system in a central control unit on the basis of a model of the energy generation plant comprising mass and spring damping elements; and
generation of nominal values for a current change difference and a phase difference of the current with respect to a generator voltage, the nominal values being used by a current control of the generator to compensate for transient oscillations in the energy generation plant,
wherein the model of the energy generation plant takes account of two active elements in the form of a wind power input and electrical power output with passive elements arranged between them, the passive elements including inductances, capacitances, and spring stiffnesses of structural elements.
2. The method as claimed in claim 1 , wherein the model of the energy generation plant is stored in the central control unit, and
wherein the central control unit is configured to use matrix equations to additively link torque vectors with a matrix of area moments of inertia, a matrix of stiffnesses and a matrix of dampings, the torque vectors being based on a rotor torque and an electromechanical torque of the generator.
3. The method as claimed in claim 1 , wherein the model takes account of linear and non-linear parameters as functions of the respective variables, the variables including torque, rotation speed and twist angle of the components of the drive train.
4. The method as claimed in claim 1 , wherein oscillations in the frequency spectrum from a number of tenths of a Hz to a number of tens of Hz on the rotor side and a number of tens of Hz to a number of hundreds of Hz on the generator side are taken into account in the model.
5. The method as claimed in claim 1 , wherein the current control is designed such that the electrical real power which is emitted into a grid system or to the load remains constant by means of a torque control, and the changes which result from the current control in the real power and the reactive power are compensated for in an intermediate circuit of the power electronics, or are additionally converted to heat in the generator windings and/or in converters.
6. The method as claimed in claim 1 , wherein the generator-side higher transient oscillations and the resonant oscillations in the drive train are controlled by the current control of the generator.
7. The method as claimed in claim 1 , wherein rotation angle position sensors are arranged at least on the output-drive shaft of the generator, on the drive shaft of the generator and on the rotor, and their measured values provide input variables for the central control unit.