The popularity of Watt's improved steam engine was rapid, and by 1790 the old Newcomen steam engine was out of sight, and by 1790 there were about 500 steam engines operating in Britain. After less than 100 years or so, by 1868, there were as many as 75,000 steam engines in Britain alone. In 1805, the steam engine in the United States was equipped with cars as a driving force. In 1807, Robert Fulton (1765-1815) of the United States invented a steamship powered by a steam engine. In 1825 George Stephenson (1781-1848) created steam locomotives that could run on rails. The high pressure steam engine was invented by Richard Trevithik (1771-1833) of England in 1800. In 1801, American Oliver Evens (1755?-1819) built a really useful high-pressure steam engine.
When the speed governor is used, the initial operation is normal. However, when the speed of the steam engine increases, the governor cannot run steadily, there will be a phenomenon of fast and slow. The first to study the stability of Governors was the British physicist James Clerk Maxwell (1831-1879). Maxwell's On Regulator published in 1868 first described the motion state of speed governor by differential equation. He derived the differential equation of governor and linearized it near the equilibrium point. It was pointed out that the stability depends on whether the root of characteristic equation has negative real part. Maxwell studied the specific system described by the third order differential equation and the special system with the fifth order differential equation, and gave the stability conditions of the system.
Later, in 1872, Vesnegrasky of Russia (1072 Like Maxwell, he uses linearization to simplify the problem and obtains more complete stability conditions.
Speed governor is a technical invention, because of its importance, it began to use steam engine in general, and thus the industrial revolution. The study of industrial cybernetics can also be said to begin with the study of governor. And the study of the stability of governor leads to the beginning and depth of the study of the stability of mechanical system. Therefore, it is very important to understand the history of governors for understanding the history of steam engines, for understanding the history of cybernetics, and for understanding the history of motion stability research.
1.The basic task of speed governing system
(1) The steam turbine operates independently and adjusts the intake of the steam turbine when the operating conditions change, so that the speed of the steam turbine can be kept within the prescribed range.
(2) When the steam turbines are integrated into the power grid, the load of the steam turbines will be adjusted to keep within the prescribed range when the power grid cycle changes.
(3) For steam turbines with regulated extraction, when the operating conditions of the steam turbine change, adjusting the extraction pressure is within the prescribed range.
The work of a turbo generator is determined by the balance between the action moment M of steam acting on the turbine rotor and the load reaction moment M resistance of the generator rotor. When the force is equal to the reaction force, i.e. M steam = M resistance, the turbo generator is in a stable condition of constant speed rotation. However, the electricity consumption of external users is constantly changing, that is, M resistance is constantly changing, so the intake of steam turbine must be changed accordingly to ensure that M steam = M resistance. Otherwise, the speed of the turbine will change greatly with the external load. When the external load increases, the speed decreases, while the external load decreases, the speed increases. Therefore, the electric voltage and frequency of the electric energy and frequency are always high and low, which is absolutely not allowed. In order to ensure the power quality and safe operation of the unit, all units must be equipped with speed control system to adjust the steam intake of the turbine to adapt to changes in external load.