Turbine Speed Control Research Articles

Control by variable rotor speed of a fixed-pitch wind turbine operating in a wide speed range

Variable rotor speed control of a fixed-pitch wind turbine is investigated on a system consisting of a wind turbine which can operate in a wide speed range, from 0 to 38 RPM. It produces any desired output from the rated (20 kW) to no-load, providing there is enough wind. A special technique is used to determine the operating point of the wind turbine by using the measured rotor speed and power. A difficult problem with this type of wind turbine control is to make the upper speed limit reasonably high to capture as much energy as possible but still low enough to avoid power peaks.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

The speed control of a momentum turbine

This paper presents a practical scheme for speed control of a momentum turbine. The scheme uses an ordinary governor to sense the speed error of the underground spinning wheel and then generates the actuating signal needed to move the position of the torque applicator relative to the spinning wheel. While the proposed control scheme is expected to be sluggish in its operation, the analysis presented in the paper shows that the desired speed of the wheel can never be attained following a load change unless the basic scheme is augmented by an integral mode of control. It is suggested that, in practice, this can be easily achieved through use of a standard hydraulic valve-ram component. The numerical results presented in the paper indicate that the inherent sluggishness of the basic scheme can be reduced to a certain extent by choosing a higher value of damping associated with the mechanical load.

Rotation Speed Control of Horizontal Axis Wind Turbine by Tip Vane.

The paper describes about the rotation speed control of horizontal axis wind turbine by tip vane. Tip vane has the excellent ability to improve the performance of horizontal axis wind turbine. Also, we found that the rotation speed of wind turbine is controlled by the change of sweep angle of tip vane. The relationships among the sweep angle of tip vane, the change of wind speed and the rotor speed are investigated. As the results, the method to keep the constant rotor speed by means of electro-mechanical apparatus is developed, when wind speed changed.

Reduced Order Compensator for Feedforward Regulators

An approach to the design of feedforward regulators by parameter estimation techniques is presented. Given a linear minimum phase system and a prespecified feedback, optimal feedforward filter design is straightforward. A method to solve for it with any input signal is given, allowing the compensator parameters for a prescribed order to be adjusted in a minimum output energy sense. For stocnastic inputs the solution with the complete order converges to the LOG-optimal design feedforward regulator. The feedforward link is optimized with respect to the measurable disturbances. The method requires knowledge of the system and tne disturbance model and can accomodate non minimum phase plants and larger delays in the plant than in the disturbance model. An example applied to a hydraulic power generating turbine speed control is presented.

Fault Tolerant Control and Safety Systems for Large Steam Turbines

The stringent requirements regarding availability of large turbine generator sets have led to the development of control and safety systems capable of withstanding malfunctions without impairing the production of electricity. These fault tolerant systems are made up of modules from the Microrec range to equip French nuclear units of 1300 and 1500 MW, in order to avoid any loss of power production subsequently to a failure of such a system. Three Identical and separate channels ensure the basic control (turbine speed control and governing valves opening). Automatic operation functions, such as speed run up, load variations, remote control, are ensured by a calculator. In case of fault it is automatically disconnected. The unit is then operated in a manual mode through the basic controllers. The safety system consists of three fail safe electric safety channels actuating a control circuit common to all the steam admission valves and an automaton for supervision and routine tests. These channels operate on a two-out-of-three basis. This equipment whose technological characteristics are described, uses micro-processors except for the protection channels which feature a hard-wired logic system.

Water Turbine Generator Modelling and Speed Control in a Small Hydropower Station

Abstract In this paper we present some results of a project on modelling and speed control in a small hydropower station placed in Puente Caldeias (Pontevedra). We present a model based on literature studies and practical experiences on the station. Moreover we show the experiences when using an industrial analog regulator, and the design and implementation of a digital state-feedback regulator.

Wind Turbine Speed Control by Automatic Yawing

A yaw dynamics analysis was developed for a two-bladed horizontal axis wind turbine with passive cyclic pitch variation achieved by letting the blade pair freely oscillate about a common axis with which the blades formed a small prelag angle. This type of rotor was found capable of high yaw rates without imposing vibratory hub moments and without producing noticeable flapping amplitudes. Experiments were conducted with a tail vane stabilized 7.6-m-diam wind rotor driving a three-phase alternator tuned and loaded to produce a rotor torque proportional to the square of the rotor speed. Two yaw control systems which replaced the usual blade feathering controls were investigated: an active yaw control system using a hydraulic rotor speed governor, and a passive system responding to a combination of rotor thrust and torque. During strong gusts both systems limited rotor speed quite accurately. The passive system appeared to be more promising because of its greater reliability and because of the greater ease of adapting it to larger size wind turbines.

Adaptive digital control of a steam turbine

The application of recent techniques of identification and adaptive control to the speed control of a steam turbine is investigated. A minicomputer was used for data acquisition, off-line and online identification and adaptive control. The turbine was modelled under different loading conditions using a recursive linear least-squares method. Although such a system is complex, second-order models were found to give reasonable results. A digital proportional-plus-integral controller with an additional feedback term was implemented to control the speed of the turbine. The controller was then made adaptive by maintaining the position of the closed-loop poles constant. This gave better performance when the turbine underwent step changes in the load. The programming required for such implementation is discussed.

Paper 13: Recent Developments in the Control of Industrial Gas Turbines

This paper describes the control systems required for the application of gas turbines to fully automatic generating stations, and mechanical drives such as natural gas compressor stations. Gas turbine power plant has definite advantages in that for the power output it lends itself to relatively simple fully automatic operation of the overall plant and rapid starting and loading. The relatively low capital cost and size have resulted in widespread applications of this type of plant. The large gas turbine plant can be divided into two main categories: (1) Aero powered gas turbines. (2) Pure industrial gas turbines. The role of the control system is not only to adapt the gas turbine to the particular application but to ensure the safety and protection of the plant at all times. The control functions include: Those necessary for the particular application, e.g. power turbine speed control. Those necessary for the protection and correct operation of the gas turbine system, e.g. balance of multiple gas generators discharging into power turbine. The peripheral systems, e.g. automatic sequence systems for starting. This paper is based on the author's recent experience in this field.