Speed Governor Research Articles

Steady-State Stability Limits of a Regulated Synchronous Machine Connected to an Infinite System

The Routh-Hurwitz criterion and the D-partition method are used in the steady-state stability study of a synchronous machine connected to an infinite bus bar. The machine has a continuously acting voltage regulator and a speed governor. The effects of the saliency and the short-circuit ratio of the synchronous machine, and that of the tie-line resistance and reactance on the stability of the system, are investigated.

Hydraulic Speed Governor With Major Governor Problems Solved

The dashpot-type isochronous governor (which may be modified by droop) is the standard hydraulic governor in current use for prime movers. This governor is designed to give proportional-plus-integral (actually, rate-responsive) control. The governor has the advantages of giving constant speed control where desired; it can be adjusted to compensate for a low value of damping in the engine system to be controlled, and it has a dashpot including a needle valve whereby one of the governor constants can be varied readily. Disadvantages of hydraulic governors in common use are the poor adjustability of control parameters; too small needle valve openings for normal applications; sensitivity of the dashpot to variations in the viscosity of dashpot oil causing corresponding variations in control parameters; floating (receiving or proportioned pistons that can and do stick; and the relative noninterchangeability of the governors from one type of engine to another. In the new governor described in the paper the foregoing problems and others not mentioned are all solved with the aid of a technique for hydraulic addition. In contrast to current governors, governor parameters including governor time lag can be adjusted independently. Load control can be introduced to the governor without the need of an extra servomotor. Nonlinearities are incorporated to improve performance. This governor is a radical departure from existing units greatly increasing the flexibility and reliability of the speed governor.

Closure to “Discussions of ‘Hydraulic Speed Governor With Major Governor Problems Solved’” (1965, ASME J. Basic Eng., 87, pp. 8–11)

Closure to “Discussions of ‘Hydraulic Speed Governor With Major Governor Problems Solved’” (1965, ASME J. Basic Eng., 87, pp. 8–11)

Discussion: “Hydraulic Speed Governor With Major Governor Problems Solved” (Oldenburger, Rufus, 1965, ASME J. Basic Eng., 87, pp. 1–8)

Discussion: “Hydraulic Speed Governor With Major Governor Problems Solved” (Oldenburger, Rufus, 1965, ASME J. Basic Eng., 87, pp. 1–8)

Discussion: “Hydraulic Speed Governor With Major Governor Problems Solved” (Oldenburger, Rufus, 1965, ASME J. Basic Eng., 87, pp. 1–8)

Discussion: “Hydraulic Speed Governor With Major Governor Problems Solved” (Oldenburger, Rufus, 1965, ASME J. Basic Eng., 87, pp. 1–8)

Discussion: “Hydraulic Speed Governor With Major Governor Problems Solved” (Oldenburger, Rufus, 1965, ASME J. Basic Eng., 87, pp. 1–8)

Discussion: “Hydraulic Speed Governor With Major Governor Problems Solved” (Oldenburger, Rufus, 1965, ASME J. Basic Eng., 87, pp. 1–8)

Effects of prime-mover governing and voltage regulation on turboalternator performance

The paper outlines the frequency-response analysis of a steam turboalternator using reheat, and examines the dynamic response of the unit when connected to a large power system.A mathematical representation of the system is made by linearising the nonlinear differential equations of motion using small-perturbation theory.Transient stability of the system is shown to be affected by feedback parameters introduced by the prime-mover governor and the voltage regulator. Limitations of the speed governor under transient conditions are discussed, and alternative methods of governing are examined. The method of analysis makes use of feedback-control theory, and system responses are represented on Bode diagrams.

The New England Electric System Tests Effectiveness of Stop-Valve Bypass in Reducing Thermal-Stress Gradients in Steam Turbines

The stop-valve bypass valve enabling full-arc admission starting is now being utilized extensively as a means of reducing transient thermal-stress gradients in steam turbines. This paper describes, with the aid of start-up test graphs, the results of an intensive series of tests conducted by the New England Electric System, which was designed to determine the effectiveness of this bypass valve. One of the machines tested was equipped with an electrical long-range speed governor which was used to bring the turbine to speed in a predetermined and accurately controlled way. This installation represents the first successful application of this device on a General Electric Company steam turbine-generator. A brief description is included.

Power system automatic frequency control techniques

The main reasons for the adoption of automatic control techniques in power systems are given and the position on their application to the British Grid system is stated. The behaviour of speed governors in amanually controlled system, leading to the development of the electrical governor, is discussed, and a Swedish governor of this type is described. The need for mixed power-frequency control and the merits of frequency-bias tie-line control are discussed. A distinctionis drawn between automatic control which only trims manual load dispatching and fully automatic loading schemes. The necessary elements of an automatic control are next mentioned, and as examples of precision frequency meters, British and German developments are described. Alternative methods of achieving desired participation inregulation are mentioned, and particulars are given of a scheme developed in Britain, including details of the machine controllers and system controller. Some test results are give.Finally the use of system simulators is mentioned and British and German simulators are described.

Feedback Theory and Its Applications

By P. H. Hammond London : English Universities Press Ltd. Pp. 348. Price 35s. This work is intended for postgraduate engineering and physics students but there is little doubt that many parts of it are suitable for undergraduate engineers at universities. The book could have been made even better for the latter purpose if it had included a lengthier treatment of mechanical systems and analogues, although a speed governor is treated at the very beginning of the book as an example of a nonlinear element and incidental mention is made here and there of other mechanical analogues (on page 190, for instance, where a mechanical transitional lead system is treated).

Steady-state stability of synchronous generators as affected by regulators and governors

Voltage and power-angle regulation can be used to improve the steady-state stability of synchronous alternators, whereas speed governors and tie-line power controllers often introduce instability.In the paper, methods of determining the effects of voltage and angle regulation on the steady-state stability limit are discussed, and they are extended to allow for the control of the prime-mover torque by means of governors and power controllers. The machine analysis is based on the general equations for synchronous machines.A complete analysis of actual problems is rather tedious, and a differential analyser has been found most suitable for detailed investigations. Results, as obtained for typical alternators, are presented in the form of stability contour diagrams, which are very convenient for design purposes, since optimum control parameters can be read off directly.

Test on the Characteristics of Speed Governor

Test on the Characteristics of Speed Governor

Steady-state stability of synchronous generators as affected by regulators and governors

Voltage and power-angle regulation can be used to improve the steady-state stability of synchronous alternators, whereas speed governors and tie-line power controllers often introduce instability.In the paper, methods of determining the effects of voltage and angle regulation on the steady-state stability limit are discussed, and they are extended to allow for the control of the prime-mover torque by means of governors and power controllers. The machine analysis is based on the general equations for synchronous machines.A complete analysis of actual problems is rather tedious, and a differential analyser has been found most suitable for detailed investigations. Results, as obtained for typical alternators, are presented in the form of stability contour diagrams, which are very convenient for design purposes, since optimum control parameters can be read off directly.

蒸気タービンの調速機特性

蒸気タービンの調速機特性

TURBINE OILS and Lubricating Oil Systems

Previous sections in this series appeared in our October, November and December, 1953, issues and dealt respectively with Properties of the Lubricant and Typical Turbine Lubricating Systems : Speed Governor and Emergency Control Systems ; The Hydrogen Cooled Alternator. Part Five will deal with the Laboratory Evaluation of Turbine Oils.

Prime mover speed governors

OPERATORS OF power generating equipment realize that it is desirable from a system control point of view to have all speed governors on their interconnected systems with reasonably similar steady-state characteristics. Normal load changes then would be shared by all units in proportion to their ratings and the action of supplementary controllers would be uniform. This would result in smaller deviation of frequency and load distribution from the desired values. Most attempts to make all prime movers on a system respond to system changes in proportion to their ratings have been confined to setting all speed governors so that they have equal steady-state speed regulation. Tests show that the response of prime movers to changes in system frequency or to the action of supplementary controllers is of a random nature and has little relation to machine rating or steady-state speed regulation. This article outlines the factors that contribute to the random nature of prime mover response and indicate how testing programs for existing units, as well as future design changes of governing systems, can produce a major improvement.

Prime Mover Speed Governors and the Interconnected System [includes discussion

Prime Mover Speed Governors and the Interconnected System [includes discussion

調速機最近の諸問題

調速機最近の諸問題

A New Automatic Load Control for Turbine Generators

In an interconnected power system, load changes of sufficient magnitude to affect system frequency are normally shared by all the generators on the system in proportion to their ratings and the characteristics of their governors. This inherent sharing of load changes is highly desirable in the majority of cases. It may, however, present a problem in a few instances if some of the generators are remote geographically and electrically from that part of the system which includes a large fluctuating load. In such cases it would sometimes be preferable if the load changes could be confined in whole or in part to the local generators, thereby relieving the remainder of the system from having to respond to distant load fluctuations. This situation may become acute in the case of systems interconnected through long tie lines, where abrupt load changes in either system result in large transfers of synichronizing power through the interconnecting ties. This paper describes a new automatic load control arrangement which has the ability to respond to local load changes in anticipation of their effect on system frequency. At the same time, however, it does not deprive the conventional speed governor of its ability to control the prime mover input to help maintain constant system frequency. In this latter respect lies its essential and unique difference from other somewhat similar arrangements described previously. <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1,2,3</sup>

Performance characteristics of speed governors

THE PERFORMANCE CHARACTERISTICS of speed governors on automatic extraction turbines as related to the performance characteristics of governors on straight condensing and noncondensing extraction turbines are affected by the characteristics of the turbines themselves. “Steady state regulation” and “overspeed” may require either special treatment or additional mechanism in the governing system in order to maintain acceptable values. The addition of the “extraction pressure regulating system” requires correlation of its action with that of the speed governing system, if the additional duty that otherwise would be imposed on the speed governor is to be avoided.