JPH01110094A - Auxiliary machine rotation speed control method - Google Patents

Abstract

PURPOSE:To simplify the rotating speed controller of an auxiliary machine and to reduce its cost by gathering auxiliary machines which tend to operate under the same operating conditions, and simultaneously controlling their frequencies. CONSTITUTION:Frequency converters 6, 7 for simultaneously controlling the frequencies of auxiliary machine groups 4, 5 are provided between a high voltage bus 1 in a station and auxiliary machines 2A-2Z (3A-3Z). The groups 4, 5 are composed by gathering the auxiliary machines which tend to have the same relationship between unit loads and operating points of the auxiliary machines necessary for operating a plant, and further gathering the auxiliary machines 2A-2Z (3A-3Z) having the same number of poles. The machines 2A-2Z (3A-3Z) are operated in the frequency of the maximum frequency of the machines 2A-2Z (3A-3Z) simultaneously by the converters 6, 7.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a system for controlling the rotation speed of auxiliary machines, and in particular, a system for controlling the rotation speed of auxiliary machines for a large number of different uses by adjusting the frequency. The present invention relates to a rotation speed control system for auxiliary machinery suitable for

[Conventional technology]

Conventionally, the rotation speed of auxiliary machines in thermal power plants and the like has been controlled by installing a frequency conversion device for each auxiliary machine and performing one-to-one rotation speed control.

Furthermore, as seen in Japanese Patent Application Laid-Open No. 60-125199, a single frequency converter is used to control the rotational speed of a large number of motors, and individual fine adjustments are made using existing eddy current joints. There is a two-stage rotation speed control system. However, the combination with valves, dampers, etc. is not discussed.

[Problem that the invention seeks to solve]

In the above-mentioned conventional technology, when installing a frequency converter for each thermal power plant auxiliary equipment, there are problems such as the installation of one frequency converter as a whole requires a large space and increases costs.

In the case of the two-stage rotational speed control method, the rated output limit of the motor to which the eddy current coupling device can be applied is small, so it has been difficult to apply it to the auxiliary equipment of thermal power plants of several thousand kilowatts.
- The purpose of the present invention is to provide a compact and low-cost method for controlling the rotation speed of auxiliary machines for controlling the rotation speed of auxiliary machines for multiple, large-capacity thermal power plants, etc. for many different uses. It's about doing.

Means for Solving Problem C] The above purpose is to handle multiple auxiliary machines for a large number of different purposes under plant operating conditions, such as when the flow rate handled by an auxiliary machine increases as the unit load increases. Auxiliary machines that show the same tendency with respect to operating conditions are compiled and further classified by the number of motor poles to form one auxiliary machine group. This is achieved by providing an integrated frequency conversion device that can cover the entire operating range for this group of auxiliary machines.

[Effect]

A frequency converter installed for a group of auxiliary machines that performs collective control controls the operating frequency of the auxiliary machine whose operating frequency is the highest among the auxiliary machines, and controls the flow rate of each auxiliary machine. - This can be done without problems by narrowing down the deviation between the operating point by comprehensive frequency control and the required operating point of each auxiliary machine using existing valves, dampers, etc.

〔Example〕

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

The figure shows an example in which the present invention is applied to an in-house auxiliary motor of a thermal power plant.

A frequency conversion device 6.7 is provided between the high-voltage bus 1 and the auxiliary machines 28 to 2Z (3A to 3Z) in the station to collectively control the frequency between these auxiliary machine groups 4 and 5. These auxiliary equipment groups 4 and 5 are those in which the relationship between the unit load and the operating point of the auxiliary equipment necessary for plant operation tends to be the same, and the number of poles of the auxiliary equipment 2A to 2z (3A to 3Z) is It is made up of the same things. The auxiliary machines 2A to 2Z (3A to 3Z) are connected to the auxiliary machines 2A to 2Z (3A to 3Z) by the frequency converters 6 and 7 in
3Z) must be operated at the highest frequency. Here, to explain using auxiliary equipment group 4 as an example, only the highest operating frequency corresponding to the unit load of auxiliary equipment 2A to 2Z is taken out, and the frequency vs. unit load characteristics that are connected in the entire unit load range are calculated. The operating frequency of the auxiliary machines 2A to 2Z is set to the highest operating frequency of the auxiliary machine group 4 by the command device [8, 9 with which the auxiliary machines 2A to 2Z have flow rate control] The deviation between the operating point based on the operating frequency (estimated high frequency) and the operating point required for plant operation of each auxiliary machine can be made by adjusting existing valves or dampers 10A to 1 oz.

The opening signals to the valves or dampers IOA to IOZ at this time are command devices that give the difference between the head at the operating frequency of the frequency converter 16 and the head required for plant operation of the individual auxiliary machines 2A to 2Z! ! It is carried out by 12.

(11A to 11Z are dampers) [Effects of the Invention] According to the present invention, one frequency converter can be comprehensively used to control the rotation speed of a plurality of auxiliary machines for a large number of different applications, and is compact and low-cost. It can be realized.

[Brief explanation of the drawing]

The figure is a system configuration diagram of an embodiment of the present invention.

Claims (1)

[Scope of Claims] 1. In a system for controlling the rotational speed of auxiliary equipment using a frequency converter, auxiliary equipment that exhibits similar operating trends under certain conditions are collected to form a group, and each of the auxiliary equipment exhibits a similar operating tendency under certain conditions. A system for controlling the rotational speed of auxiliary equipment, characterized in that it is equipped with a batch frequency converter that operates at a constant rate at an operating frequency of .