JPS58201561A - Protecting device for brushless turbine generator - Google Patents

Abstract

PURPOSE:To rationally and safely protect a rotor against a reverse phase load by detecting various physical values on the rotor without contact and particularly monitoring the temperature of a cross slot end to protect a brushless turbine generator. CONSTITUTION:The magnetic resistant voltage, exciting current and cross slot end rotor surface temperature of a main exciting circuit are respectively detected by resistors 22, 23 and a temperature detecting sensor 27, and the detected outputs are inputted through amplifiers 30, 31 to a modulator 33. The output of the modulator 33 is inputted through a modulator 35 provided at the exterior of a rotor 1 into an arithmetic processor 36. The processor 36 obtains exciting voltage, exciting current, exciting coil resistance, exciting coil average temperature and the surface temperature of the cross slot end, and delivers the outputs to an indicator 37 and an alarm and trip circuit 38.

Description

[Detailed Description of the Invention] [Technical field of Q11] The present invention uses a rotary rectifier to convert the armature output of an AC exciter! Regarding the rotor maintenance method of pushless excitation rotating electric machines, which is excited in addition to the main machine field with Ifi, it is particularly important to use reverse-phase synchronous machines with rotor structures such as turbine generators that have long shafts and block magnetic poles. This invention relates to a protection device that protects against overheating that occurs during operation.

[Technical Background of the Invention] The rotor of a conventional rotating electric machine will be explained using the first trochanter of 11 brushless turbine generators shown in FIGS. 1 and 2 as C. FIG. 1 is a diagram showing a conceptual configuration of a rotor of a brushless turbine generator, and FIG. 2 is a cross-sectional view showing a plane including an iron core in a cross slot of a single trochanter. In the figure, the - trochanter 1 is composed of an iron core 1a and a shaft portion Ib.
The nine field coils 6 housed in the coil slots r cut in the axial direction of the FC core JJLK are li! ! 2 so that the number of layers does not increase in the outer diameter direction.

Further, the end portion of the field coil 6 is fitted into the rotor body and held by nine retaining rings S.

Furthermore, in such a rotor, the axial length of the block iron core is long, and if only the coil slots 7 are provided, the rotor axis sO When supported at both ends, the axial rigidity differs, which causes vibration during multiple rotations, so in order to equalize the rigidity, a cross slot 5 cut in the circumferential direction is provided in the magnetic pole part 4, and the coil slot part and Normally, the rigidity of the magnetic pole parts is the same. Note that, as shown in FIG. 2, the cross slots 5 are formed in a circular arc shape in consideration of ease of processing, and a plurality of cross slots 5 are provided in the longitudinal direction of the shaft.

On the other hand, in a turbine generator having a rotor made of a block iron core (such as the one described above), during unbalanced load operation or asynchronous operation, when a sudden terminal short-circuit occurs, a circulating type fi (vortex) occurs alternately on the rotor surface. Electric current (It) flows and heats the rotor surface. Therefore, it is necessary to prevent overheating due to this eddy current and increase the negative phase load capability, and therefore, research has been conducted in many fields to find a quiet loss distribution.

FIG. 3 is a developed diagram showing the relationship between cross slots and pulley slots on the rotor surface and the flow of eddy currents. Note that C in the figure indicates the center line of the magnetic @ portion. In the figure, when the generator O is operated under a reverse phase load, eddy currents are induced on the rotor surface as indicated by streamlines 9 indicated by arrows. Although some of these eddy currents partially flow along the inner surface of the cross slot 5O due to their physical properties, most of these eddy currents flow concentrated in the coil slot Fa() IF11 adjacent to the cross slot 5. In particular, the concentration near the JO terminal (cross slot) is remarkable, and as shown by the solid line in the loss Wi degree distribution diagram in Figure 4, the loss density is several times higher than that at the center of the magnetic pole, heating the area in a whs manner. This area shows the greatest temperature rise on the rotor surface.

Now, in order to protect such a brushless turbine generator from overheating due to the above-mentioned running phase current, its limiting characteristics are determined by setting the negative sequence current to 17, the time to t, and l1t- to a constant K. There is.

FIG. 5 is a block diagram showing the configuration of a negative phase overcurrent relay for this purpose. In the 51st prisoner, 12 is an anti-phase filter, and this anti-phase filter 12 generates a secondary current I of a current transformer installed in the main circuit of the machine from a turbine (not shown).
When R, IB, and IT are given, they are converted into a voltage VK51' proportional to the negative phase current. 13 is a minimum operating value circuit which is set as the minimum operating value and operates when the output voltage V of the negative phase filter 12 reaches the 9th level detection value;
Reference numeral 4 denotes an alarm circuit, which operates when the output voltage V of the anti-phase filter 12 is set as an alarm generation value and reaches the 9th level detection value; 15, the output voltage V of the anti-phase filter 12 is input, and a minimum operating value circuit 13; The operation output of the multi-operation type
When the above-mentioned operation formula starts to run on the I: twitl path where x K starts to be read, a trip signal 'rp is output.

[Problems with background technology]

By the way, the method of detecting the negative sequence current from the main circuit of the pushless turbine generator and maintaining the rotor based on that value as described above cannot be said to be sufficient from the following points. If kept, short-term reverse phase tolerance (knee t = Kt)
The value only gives an indication of the negative sequence current value O that the rotor can withstand due to heat accumulation, and due to the difference in heat conduction and heat transfer on the rotor surface when the time t is long and when the time t is short, In fact, the results show a completely different result in terms of temperature rise. 1
19. From the perspective of reverse phase resistance, the conventional O-protection method is against the average temperature increase (To), and the most difficult jRJ
It does not protect against the maximum temperature of s. In particular, in the case of gas-cooled power generation @ 0, even the average temperature rise value will differ depending on the gas pressure during operation, and the rotor insulation method based on the suiyang current is ineffective. This is clear from this point as well.

[Purpose of the invention]

This project was developed in view of the above circumstances, and its purpose is to develop a line maintenance device for brushless turbine generators that can rationally and safely protect the rotor from negative phase loads. It is about providing.

[Outline of output Wj4o] In order to achieve the above object, the present invention accurately detects various physical quantities on the rotor of a brushless turbine generator in a non-contact manner. The feature is that the lif & of the cross slot end is monitored and maintained.

[Implementation sequence of the invention]

Hereinafter, one embodiment of the present invention will be described with reference to the drawings. FIG. W, 6 shows a configuration sequence of a protection device for a brushless turbine generator according to the present invention. In the figure,
The brushless turbine generator rotor 1 is not shown. The output of the AC exciter armature winding 200, which generates a three-phase alternating current by DC exciting the field winding of the current exciter, is exchanged to direct current via the rotary rectifier 21, and the output of the AC exciter armature winding 200 is changed to direct current through the rotary rectifier 21, and the direct current is applied to the magnetic field C outside the main machine. It has a pushless excitation configuration that supplies excitation current.

Separately from the main engine excitation circuit, the rotor IK has a secondary winding that generates electric power in a non-contact manner by AC excitation of the 40-turn transformer-next winding, which is installed between the fixed tubes. A line 40b is provided. Then, this AC output is given to a separately provided DC stabilized power supply S9, and the DC stabilized output is sent to separately provided amplifier circuits go, sx, and controller 3.
2, f-circuit JJKJ is supplied.

In addition, the outputs of the voltage dividing resistor 22 and the shunting resistor 23 provided in the main engine excitation circuit are inputted to the amplifier circuit Jo, so that it can output a signal proportional to the excitation voltage and current. ing. The other amplification path 11 is equipped with a temperature detection sensor 27a (a lead wire is provided in the adjacent coil slot) for detecting the rotor surface temperature between the cross slot 5 and the coil slot 1a, as shown in FIG. Enter the output and
It is possible to output a signal proportional to the temperature of the fixed point to be outputted. Here, the temperature detection sensor 77a is provided using the inside of the coil slot 7 which is connected to the cross slot 5. Mayu, these amplifier circuits 30.3
1 mainly has the functions of analog-to-digital conversion, multi-point signal discrimination, and signal shaping, and is controlled by the controller 32, which shapes the input signals and converts them into analog-
The multi-point signal is discriminated by digital conversion and outputted to the variable s1 circuit 33. Further, the modulation circuit 33
is controlled by the controller 32, changes each discriminated signal, and inputs it to the tsii circuit 35 via the transmitting antenna 34 and the receiving antenna S4 provided on the stator side to be coupled thereto. do. As described above; if controlled by the controller 12, even if multiple points are measured at the same time, they can be transmitted to the stator side using radio waves in an orderly manner, and the variable rate circuit S5 provided on the stator side can transmit signals proportional to the amount of electricity. It is converted into an electrical signal and input to the arithmetic processing circuit 16, where the electric quantity, that is, the excitation voltage/electricity in the case of multiple rows, tIL and excitation winding resistance, the excitation winding average temperature 1, and the surface of the end of the Talos slot is calculated. The temperature is processed and input to the display device S1 and the alarm/trip circuit 38.

Here, the display device 37 has a function of displaying and recording each quantity of electricity, and generally uses a digital device. The alarm/trip circuit 38 issues various alarms regarding generator operation due to heating of the rotor surface and temperature rise of the excitation winding due to an increase in negative phase load, and in some cases issues a generator trip signal. It's for something.

With such a configuration, there are very small parts and parts on the rotor.
By simply installing a circuit, the electrical connection on the rotor of a planless turbine generator can be detected completely without contact, and the color can be detected, especially if the local temperature rise on the rotor surface is the largest regardless of the operating state. Cross slot) 5t4 temperature can be congratulated, 4
It eliminates the shortcomings of the conventional protection method based on the negative sequence current, which has a different m-rise of the trochanter, and can provide highly reliable negative sequence load protection in a rational and safe manner. becomes. This greatly contributes to the current large capacity and =1(1) high reliability of brushless excitation type machines, which aim to simplify operation and maintenance and improve reliability.

In addition, since the rotary transformer 40 is used to supply the 12 source to each circuit for 1 bloom measurement, the t source can be supplied non-contact during any period of time during stoppage or startup. It is necessary to provide a separate power supply for adjustment, etc., and maintenance and adjustment of the entire detection and measurement system is facilitated. If this is not necessary, it is possible to install an auxiliary winding on the AC exciter armature or take measures such as branching the AC output, even if power is not supplied using a rotating transformer. It is clear that I will return.

Note that the above device detects and measures three types of signals: voltage, current, and temperature, but when viewed as electrical signals, they are all the same. Of course, it is also possible to measure stress, acceleration, etc. in the same way.

In addition, the present invention can be modified in various ways without changing the gist thereof.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to provide an extremely reliable protection device for a brushless turbine generator that can rationally and safely protect the rotor from negative phase loads.

[Brief explanation of drawings]

Fig. 1 is a perspective view showing the conceptual structure of the rotor of a turbine generator, Fig. 2 is a cross-sectional view showing a plane including the iron core in the cross slots of the ATM trochanter, and Fig. 8 is a cross-slot and coil on the rotor surface. Figure 4 is a diagram showing the loss IIR & distribution along the circumferential direction in the vicinity of the cross-slot, and Figure 5 is a diagram showing the configuration of a conventional reverse phase-current relay. FIG. 6 is a block diagram showing a single row of m-rows according to the present invention, and FIG. 7 is a diagram showing a cross slot provided with a temperature detection sensor at the end of the cross slot according to the present invention. l-rotor, Jlk-core, Jb...shaft, 2-...
Horizontal, '-holding II % 4-magnetic pole, 5-・cross slot), +It-・coil, F, 7a... coil slot, 9-eddy current fIt, wire, 11-・narrowing between coil slot and cross slot Gap, 12 - reverse phase filter, 1
3-minimum operating value circuit, 14-...alarm circuit, 15 construction: t
zKm path, 10--grey stator winding, 20--AC exciter armature winding, 21--rotating rectifier, 22-voltage division resistor, 2B--shunt resistor, 24--for measurement Slip ring, 25... Arithmetic circuit, 26... Front troller, 3
3... Variable 1 circuit, etc., 34a, 34b... Antenna,
35...ffI4 circuit, 36... Arithmetic processing circuit, 3
7...Display device, 38...Alarm trip circuit, 39
...DC stabilized power supply, 40&, 40b-rotating transformer. Applicant's agent Patent attorney Rin Ushiki Hiko No. 311 Figure 4

Claims (1)

[Claims] A fi + stator and a rotor with a long axial length and block magnetic poles -
In the developed brushless excitation type turbine generator, each detection element detects the excitation voltage and current of the main @magnetic circuit and the surface temperature of the cross slot end rotor and outputs an appropriate electrical signal, and the electricity from each detection element is detected. Input signal, analog-digital f conversion, signal discrimination, fr! Controls the amplifier circuit that performs the No. 1 shaping, the network circuit and transmitting antenna that performs the fall to double the output of the En-Ayu by radio waves, and the amplification circuit, fl, and 161 circuit. a controller, and the amplifier circuit that converts AC power obtained from the rotary transformer into a DC output;
DC voltage constant 1 given to the modulation circuit and controller respectively
a modulation circuit which is provided with a source on the u-trochanter side, inputs an amount of traveling electricity proportional to the radio wave from the transmitting anti-t received by the receiving antenna, and supplies f with an electric signal that is advantageous to it; , an arithmetic processing circuit for arithmetic processing the output from the 0'R174@ road, and a circuit for displaying the output from this arithmetic processing circuit on the J& and outputting an alarm and a generator trip signal, respectively, on the stator side. A maintenance device for a brushless turbine generator characterized by the following nine features. (To) A purulent preservation device for a brushless turbine generator according to claim 1, wherein at least one point of the element for detecting temperature/verticality is provided adjacent to the rotor cross slot and at the bottom of the nine coil slot. (To) The brushless turbine generator O-I device according to claim (1), wherein a rotary transformer for at least ls is provided as an AC input means of the DC stabilized power source. (4) A brushless turbine according to claim (1), wherein the lead wire of at least one temperature detection knob provided in the narrow space 11 between the cross slot and the adjacent coil slot is provided and connected to the adjacent coil slot. Generator O
Holding device. (5) Claim No. 1: Protection of the brushless turbine generator of JJ Kisen, in which an auxiliary winding is provided in the 5P, R exciter armature for the brushless exciter as an AC input means of the DC stabilized power supply Device. (6) A maintenance device for a pushless turbine generator according to claim 11, wherein an AC exciter is provided for detection and measurement as an AC input means of the 1151 stabilized power source.