CN102340275A - Energy saving control method of utilizing steam for controlling for excitation of generator utilized by waste heat - Google Patents

Abstract

The invention, which belongs to the motor control technology field, relates to an energy saving control method of utilizing steam for controlling for excitation of a generator utilized by waste heat. According to the current generator utilized by waste heat, frequently parking is caused by poor stability of the steam pressure and the steam flow of the steam turbine of the generator, so that lots of high temperature steam is evacuated. However, the above-mentioned problem can be solved by utilizing the method provided in the invention. According to the method, on the basis of a steam flow and a steam pressure of a steam turbine, a control strategy that uses difference-adjusting adjustment as an inner ring and uses a constant power angle theta as an outer ring. Therefore, a technical scheme is realized; more particularly, when a steam flow or a steam pressure of a steam turbine does not exceed a stable value, a control mode is difference adjustment; when the steam flow or the steam pressure of the steam turbine exceeds the stable value, the control mode is a constant theta angle; and thus a traditional difference adjustment is replaced. Main applications are as follows: when a steam flow or a steam pressure of a steam turbine does not exceed a stable value, a generator works at a difference-adjusting inner ring, so that energy is saved to a maximum limit; and when the steam flow or the steam pressure of the steam turbine exceeds the stable value, the generator works at an constant power angle theta outer ring, so that reliability can be realized to a maximum limit; therefore, organic combination of the energy saving performance and the reliability of the generator utilized by waste heat is realized and objectives of energy conservation and emission reduction are achieved.

Description

The UTILIZATION OF VESIDUAL HEAT IN generator excitation is controlled energy-saving control method surely with gas

Technical field

Electric Machine Control

Background technology

Widely popularize today of energy-saving and emission-reduction project in country, the cogeneration of enterprise has received country and has fostered, still; Cogeneration has the characteristics of steam turbine steam pressure poor stability than water power and thermoelectricity; The waste heat of plant amount how much be the restriction that receives the explained hereafter operating mode, and the change bigger, when the steam turbine inlet steam fluctuates; Because steam turbine automatic regulating system inertia, the rotating speed of steam turbine also will fluctuate thereupon.Under the constant situation of electrical load, swing will appear in the merit angle θ of generator, and when the θ angle surpassed permissible value, generator might step-out.The excitation unit that domestic present cogeneration is used is water power or thermoelectricity corollary apparatus, cogeneration machine step-out often occurs and stops, and causes a large amount of productions to use the high-temperature vapor emptying, has not only wasted the energy, and has influenced production.Therefore, cogeneration enterprise presses for the excitation unit of high stability.

Hebei Electron Information & Academe is development, the producing and selling of specializing in synchronous machine microcomputer excitation and serves the high-tech scientific research institution of one.Scientific research experience with more than two decades is known very well the drawback of present state time generator excitation product in cogeneration is used, and is summarized as follows at present: state time generator excitation unit regulative mode is to transfer difference or constant power factor regulative mode now.Its advantage is energy-conservation, should this be a more outstanding regulative mode.But it has a fatal weakness, is exactly to suddenly change moment when the steam turbine steam pressure, because the also corresponding sudden change of active power; Transferring under the adjusting of difference or constant power factor; The exciting current fluctuation causes whole generating system pulsating, causes the generator step-out to be stopped when serious.Though and my the permanent merit angle generator excitation control device of institute's early development success has solved above-mentioned integrity problem, energy-saving effect is not obvious.In line with not only energy-conservation but also principle reliably, we have developed the cogeneration machine energy-saving control device with merit angle calibration function.

Summary of the invention

Domestic initiation adopts the control method of " controlling surely with gas " to UTILIZATION OF VESIDUAL HEAT IN generator excitation intensity.Promptly according to the steam flow and the pressure of steam turbine, adopting to transfer difference to be adjusted to interior ring, is the control strategy of outer shroud with the invariable power angle, is basis with steam turbine steam flow or pressure, and decision employing accent difference still invariable power angle is regulated.

Embodiment

Operating synchronous generator is under steam turbine steam flow or pressure oscillation situation; The merit angle θ of generator is with change; Reduce such as steam pressure, the decline of steam turbine rotating speed can make merit angle θ increase, when the θ angle increases to a certain limiting value; Generator will step-out, so the key of stabilizing synchronous power generator operation will be stablized the θ angle exactly.

Promptly when steam turbine steam flow or pressure did not exceed stationary value, control mode was poor for transferring; Otherwise control mode is HengθJiao regulates: when θ changes, timely and accurately with θ angle input microcomputer, after calculation process, feed back to the input and the given θ of adjuster ₀Compare, its deviation changes the output and the rectifier bridge silicon controlled α angle of adjuster after the PID computing, thereby realizes the purpose at its stable θ angle.Under the steam flow and pressure stable situation of steam turbine, adopt with transfer difference be adjusted in the method for ring, transfer exciting current to keep active power with the reactive power allocation proportion is constant, the assurance motor moves under power save mode; Under the steam flow and the ultra scope situation of pressure of steam turbine; Employing is the method for outer shroud with the invariable power angle, in case stability is on the hazard, just according to the merit angle excitation intensity is proofreaied and correct; Guarantee merit not overshoot of angle; Make generator exempt from outer impact of disturbing, reduce the step-out probability, guarantee motor operation under reliable state.Make generator exempt from outer impact of disturbing, reduce the step-out probability, guarantee motor operation under reliable state.

Claims (1)

1. method of controlling UTILIZATION OF VESIDUAL HEAT IN generator excitation intensity is characterized in that when steam turbine steam flow or pressure do not exceed stationary value, adopting and transferring difference to regulate, and when steam turbine steam flow or pressure exceed stationary value, adopts invariable power angle to regulate.