JPS6288001A - Digital controller for electric power plant - Google Patents

Abstract

PURPOSE:To reduce the cost of a digital controller for an electric power plant and to facilitate its maintenance by composing the digital controller entirely of a general CPU for sequence control. CONSTITUTION:The digital controller 2 for the electric power plant is equipped with a data collection path 3 for obtaining electric power plant information from plant equipment 1 and a control command path 4 and connected to an operation command device 26. This controller 2 has a sequence control part 27, an excitation control part 28, and a governor control part 29 and controls an ignition device 10, a guide vane servo 25, etc. In this case, the general CPU for sequence control is composed of a general CPU of the same type with multifunctional use or sequence control including AVR(automatic voltage regulator), GOV(Governor), etc., on a function decentralization basis; control which may be also (e.g. automatic reactive power control over excitation system) is processed by a sequencer, special functions (e.g. system stabilization) are omitted, and all kinds of generator control are performed by the CPU of the same type.

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applicable to systems where sequence control, adjustment control, etc., which require a slow calculation cycle time of the CPU, and adjustment control, etc., which require a fast calculation cycle time, are mixed. This invention relates to digital control devices in power generation plants.

[Conventional technology]

FIG. 4 is a block diagram showing a typical example of a conventional digital control device for a power plant. (1) is the power plant equipment to be controlled, (2) is the digital control device of the power plant, (3) is the data collection path for obtaining power plant information, (4) is the control command path, and (5) is the automatic voltage Auxiliary control signal path of regulator (AVR), (6) is load command path of GOV, (7) is AVRl
(8) is a system stabilization device (P) as an auxiliary control for AVR.
SS), (9) is AQR, shout is ignition device (GPG), (
11) is Cyrisk Bridge, ((3) is GOV, (1
3) WLR (14) is a broken line characteristic circuit, (15) is a guide vane servo, (10 is a rotation detector, (17) is a water wheel, (18) is a shaft, (19) is a rigging machine, (g) (19) is the field winding, (9) is the field breaker, (to) is the generator breaker, (2) is the main transformer, and (2) is the PTS body)
is an excitation transformer, and (e) is an operation command device.

Next, the operation will be explained. The digital control device (2) of the power plant receives operation commands such as start, stop, load commands, etc. from the operation command device (to), and records the operating status of the power plant J [fll] to be controlled by the data collection path (3). The power plant machine M (1) is grasped and passed through the control command path (4) according to a predetermined sequence by the digital control device (2).
control.

AVR auxiliary control signals such as set voltage and set reactive power are also controlled for AVR (71) through control signal # (51), and load limit values, load command value water level signals, etc. are also controlled for GOV (b). Control through the load command path.

[Problem that the invention seeks to solve]

Since the conventional power plant control device is configured as described above, the sequence control units M, AVR, and c.

Each Ov was controlled by an independent, dedicated device.

These devices are of a variety of types, including electromagnetic, analog, and digital types, and have different structures and configurations, which makes maintenance not only extremely difficult but also uneconomical.

This invention has been made to solve the above problems. Conventionally, excitation systems and procurement systems have required coordination, and there has been a general concept that a general-purpose CPU for sequence control cannot provide sufficient response speed, and this has been supported by dedicated single-function analog or digital controllers. , the purpose is to more simply configure the power plant's digital control system.

[Means for solving problems]

In the digital control device according to the present invention, the sequence control or adjustment function that requires a slow cycle time is centrally processed by the sequence control CPU, and when a fast cycle time function is required, the sequence control CPU is of the same type as the sequence control CPU. It aims to improve economy and maintainability by dedicating the CPU to that function and simplifying the function.

[For production]

In the control device according to the present invention, sequence control, excitation control, and adjustment M# control were conventionally performed using separate dedicated machines.
However, the functions have been distributed using a general-purpose sequencer for sequence control, and the functions are now limited to the original basic functions and additional functions, and controls that can be slow (for example, AQR in the excitation system, water level adjustment in the regulating system, etc.) are Processing was done by a sequencer, special functions (for example, AVR's PSS and GOV's polygon characteristics) were omitted, and all generator control was controlled by the same type of CPU.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. 1st
In the figure, the same reference numerals as in FIG. 4 indicate the same or equivalent parts. Trunk) is a sequence control section, (b) is an excitation control section, ii) is a procurement machine control section, and OI is a path connecting each control section.

Figure 2 shows the function of the excitation control section with the attached functions removed.
! FIG. 2 is a block diagram showing a simplified embodiment with only functions. (1) is the voltage detection section, (2) is the reference voltage, (3)
is the voltage comparator gain, (4) is the AVR output gain (5)
is an AVR time constant setting section, (6) is a limiter, and (7) is an output amplifier.

FIG. 3 is a block diagram showing an embodiment in which the functions of the speed governor control section are simplified to only the original functions by removing the accessory functions.

(1) is the frequency detection section, (2) is the reference frequency, (3) is the governor proportional gain, (4) is the governor integral gain, (5)
is the governor trace gain, (6) is the governor common gain, (7
) is the load setting, (8) is the governor drooping rate, (9) is the actuator servo section, and α0) is the guide vane servo drive section.

As shown in Figure 1, the sequence control general-purpose CPU is
Multi-functional use including VR and GOV, or sequence control by distributing functions with a general-purpose CPU of the same type as for sequence control, and adjustment control that can be performed even if the CPU calculation cycle time is slow, such as AQR, APRFlALR, ALL, and WLR. Controls with fast calculation cycle times, such as AVR functions and GOV functions, can be implemented by simplifying the block diagram to only the original functions as shown in Figures 2 and 3, and performing software processing (program processing) using a digital control device, as shown in Figure 1. The digital control device for the power plant was constructed simply as shown in the figure below.

〔Effect of the invention〕

As described above, according to the present invention, the entire digital control device of a power plant is constructed of a general-purpose CPU for sequence control, so that the device can be made inexpensive and easy to maintain.

[Brief explanation of drawings]

The first part is a block diagram of a digital control device for a power plant according to an embodiment of the present invention, the second and third parts are AVR and G
An example of a block diagram in which the circuit is simplified to include only the essential functions of the OV is shown, and FIG. 4 is a block diagram showing the configuration of a conventional digital control device for a power plant. (1) is the power plant 8i unit to be controlled, (2) is the digital control device of the power plant, 0 is the ignition device (GPG), (11
) is the thyristor blade, Qs) is the guide vane servo, (IE9 is the rotation detector, (17) is the water wheel, (18) is the shaft, (b) is the generator, ni) is the field winding, ni) is the operation Command device axis) is the sequence control section, (to) is the excitation control section, (c) is the speed governor control section 0Φ is the bus connecting each control section.

Claims (1)

[Claims] Multi-functional use of a general-purpose central processing unit (CPU) for sequence control or a general-purpose CPU of the same type as for sequence control
By distributing functions, sequence control, automatic reactive power control (AQR), automatic power factor adjustment (APFR), automatic load limiter (ALL), automatic load regulator (ALR), automatic water response device, and water level regulator (WLR) are possible. In addition to slow regulation controls such as automatic voltage regulation (AVR) and procurement (GOV)
) A power plant digital control device that is characterized by its ability to simplify functions and control them simultaneously.