JPS62196037A - Motoring detective device - Google Patents

Abstract

PURPOSE:To detect the motoring instantaneously and to protect a turbine by installing a torque sensor to the shafting connecting a prime mover to a generator and discriminating the reverse rotation in the relative direction of the torque on the prime mover side to the one on the generator side. CONSTITUTION:A load 2 is connected to a system power source 1. A turbine 7 is driven by the vapour of a boiler 9, the turning effort of which is transmitted to a generator 5 through a coupling 6. The power thus generated is connected to the system power source 1 through a transformer 4 and a breaker 3. Torque sensors 10T and 10G are installed to a turbine side and a generator side of the coupling 6 and the facing direction of axial torque is monitored with a discriminator 11. In the normal condition, it is discriminated that the turbine 7 is on the drive side and the generator 5 on the load side. When the output of the turbine 7 is lowered for some reason or other, the relative direction of torque sensors 10T and 10G are reversed and the discriminator 11 immediately discriminates the reversal on the load side and the drive side and interrupts the breaker 3. Thus, the bad influence on the turbine can be reduced.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a motoring detection device, and more specifically, in a steam turbine generator or a gas turbine generator of a thermal power or nuclear power plant, the present invention relates to a motoring detection device. The present invention relates to a motoring detection device for detecting a motoring phenomenon when driving force is cut off.

[Conventional technology]

A conventional motoring detection device for a steam turbine generator using a thermal power plant as an example will be described with reference to FIG. In the figure, the power supply on the grid side (4Tic load C).

The generator breaker (3) is connected and the generator breaker (3) is connected.
, 71 are connected to the main transformer (tIl, generator (5)) that sequentially boosts the generator voltage and transmits the power to the grid. The steam turbine (7) is connected to a boiler (9) that generates steam via a steam valve (Kl. main transformer) and a generator (s
Between 1 and 1, there are a current transformer (12) that detects the output current, a transformer (13) that detects the output voltage, and a reverse power relay (1) that operates when power flows into the generator (5) side. is provided.

With the above configuration, the steam turbine (7) has a steam valve (f
fl is opened and driven by steam from the boiler (9), it becomes a prime mover and supplies energy to one generator (s).

The generator (5) converts mechanical energy into electrical energy, generates power to the grid via the main transformer (41), and supplies it to the load (2).
supply power to Grid-side power source (C) is a power system in which many power generation facilities such as those mentioned above are connected.

Now, if the steam valve (fl) closes for some reason and there is no steam left to drive the steam turbine (7), the generator (yl
will no longer produce output, and conversely, it will take power from the grid power supply (ll) to become an electric motor and drive the steam turbine (7) as a load. This phenomenon is called motoring. When such motoring occurs, the above-mentioned As you did, the generator (
Since the direction of power from jl is reversed from power transmission to power reception, this reverse power (power reception) is introduced into the reverse power relay (/4=) via the current transformer (l-) and transformer (/J), To detect. When the reverse power relay (c) operates, the output contact of this relay opens the generator circuit breaker (,yl), and the turbine generator (5
) from the system and shut down.

[Problem to be Solved by the Invention 1] In the conventional motoring detection device using a reverse power relay as described above, the reverse power value detected by the relay is the sum of the turbine mechanical loss and the generator no-load loss, and this value is the sum of the turbine mechanical loss and the generator no-load loss. is less than 1% of the generator rating, and it is necessary to detect extremely small amounts of power. Therefore, there was a problem that the reliability of detection was low. Furthermore, since it is impossible to instantly detect the start of motoring, it is necessary to ensure that motoring occurs within the range in which the reverse power relay operates.

Another problem was that the turbine would remain in an unfavorable operating state for several tens of seconds.

This invention was made in order to solve the above-mentioned problems, and provides a motoring detection device that can instantly detect motoring without causing the motoring phenomenon to continue, and that is highly reliable in detecting motoring. The purpose is to obtain.

[Means for solving problems]

The motoring detection device according to the present invention includes a torque sensor in a shaft system that connects a turbine and a generator, and focuses on the fact that the shaft torque of the shaft system is reversed between normal operation and motoring operation, A determining device is provided to determine whether this torque is reversed.

[For production]

In this invention, the shaft torque is detected by a torque sensor, and this is constantly monitored by a determiner to see whether the turbine is on the drive side and the generator is on the load side, and conversely, the generator becomes the drive side and the turbine Motoring is instantly detected when the motor is on the load side.

〔Example〕

FIG. 1 shows one embodiment of the present invention, and in FIG. 1, a coupling (6) is connected to a torque sensor (lOG)
("T) detects the shaft torque of the generator (Sl and turbine (7)). (11) is the torque sensor (t OG
') * (/OT) This is a determiner that monitors and determines the relative direction of shaft torque.

Other than that, the reference numerals in Figure 1 are the same parts.

Next, the operation will be explained. Steam is generated in the boiler (ql), the steam valve (su) opens, the steam turbine (7) rotates, and the generator (sl) directly connected to the steam turbine (7) converts mechanical energy into electrical energy. In a normal state where the main transformer (da) boosts the voltage and supplies power to the grid load (2), the torque sensor (lOG), (#7T)
The shaft torque detected in is constantly monitored and determined by the determiner (11), assuming that the steam turbine (7) is on the drive side and the generator (sl is on the load side (driven)).

When the energy runs out, the output of generator 1yl also stops. If generator (s) remains connected to the grid in this state, generator 1 (5) receives power from the grid power supply (c) and becomes an electric motor. to drive the steam turbine (7).The generator (
At this moment when the steam turbine (5) became an electric motor, the steam turbine (
7) and the generator (51), the relationship between the shaft torque of the generator (jl
is on the drive side, and the steam turbine (7) is on the load side, reversing the normal state. By detecting this with the determiner (ll), the motoring phenomenon can be instantly and reliably detected.

Note that in the above embodiment, the torque sensor (lOG) is used.

(10T) is shown as being provided in the coupling (1,) portion, but it may be provided in any part of the shaft system of the turbine and the generator.

Furthermore, in the above embodiments, the case of a steam turbine generator has been described, but a gas turbine generator or a diesel generator may also be used.

〔Effect of the invention] The invention will be apparent from one or more of the descriptions.

Since the relative direction of the shaft torque on the drive side and load side is judged using a torque sensor and judgment device, the motoring phenomenon can be instantly detected and the chance of adverse effects on the turbine can be minimized, which is an excellent effect. There is.

[Brief explanation of drawings]

FIG. 1 is a layout and connection diagram of an embodiment of the present invention, and FIG. 2 is a layout and connection diagram of a conventional motoring detection device. (51... Generator, (7)... Steam turbine (prime mover)
, (i 0 () ) * ('OT) ... Torque sensor, (it) ... Judgment device. In each figure, the same reference numerals indicate the same or corresponding parts. ...Litigation 1°” Agent So Wado Teru 16.1 Kichi-ichi-no

Claims (3)

[Claims] (1) A torque sensor is installed on the shaft system connecting the prime mover and the generator to detect shaft torque, and the relative direction of the torque on the prime mover side and the torque on the generator side is reversed when connected to this torque sensor. A motoring detection device comprising: a determination device for determining whether the motoring has occurred. (2) Claim 1, wherein the torque sensor is disposed in a coupling part of a shaft system that connects a prime mover and a generator.
The motoring detection device described in . (3) Claim 1 in which the prime mover is any one of a steam turbine, a gas turbine, and a diesel engine.
The motoring detection device described in .