JP3537629B2 - Cross-flow protection device for cross-compound type turbine generator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cross flow protection device for a cross-compound type turbine generator.

[0002]

2. Description of the Related Art FIG. 6 is a circuit diagram showing a conventional cross flow protection device for a compound type turbine generator, wherein 1 is a P generator, 2 is an S generator, and 3 is a P generator. 1 is a P machine field circuit breaker for interrupting the field current If (P) supplied to 1, and 4 is a field current If supplied to the S machine generator 2
(S) is an S field circuit breaker. 5 is provided in the power system of the P-machine generator 1 to detect the output current of the P-machine generator 1, and 6 is provided in the power system of the S-machine generator 2, S for detecting the output current of the machine 2
The current transformer 7 includes a P-current transformer 5 and an S-current transformer 6.
A cross current a corresponding to the deviation of the output current detected by the above, and when the cross current a exceeds a predetermined value, a cross current protection relay which cuts off the P field circuit breaker 3 and the S field field circuit breaker 4 is used. is there.

Next, the operation will be described. When the P-motor generator 1 and the S-motor generator 2 are rotated by the prime mover, the P-motor generator 1 and the S-motor generator 2 have approximately the same rotation speed at about 50% of the rated rotation speed when the plant is started. , The P field breaker 3 and the S field breaker 4 are sequentially or simultaneously turned on. As a result, a voltage is generated between the P-machine generator 1 and the S-machine generator 2, and the two P-machine generators 1 and the S-machine generator 2
Goes to the synchronization state. However, two P generators 1 and S
In the case where the motor generator 2 is operated in a state where the phases are separated from each other, and when the field current If (P) and the field current If (S) vary, the two generators Crossflow occurs in

In the prior art shown in FIG. 6, this cross current is differentially connected between the P machine current transformer 5 and the S machine current transformer, and the cross current protection relay 7 causes the deviation of each output current, that is, the deviation. The cross current a is taken out, and when the cross current a exceeds a predetermined value, P
The field breaker 3 and the S field breaker 4 were shut off. Japanese Patent Application Laid-Open No.
There is 165625 gazette.

[0005]

Since the conventional cross flow protection device for a compound type turbine generator is constructed as described above, the cross flow protection relay 7 has two P generators 1 and an S generator. 2 and a cross current generated due to a difference between the field current If (P) and the field current If (S) due to a phase difference between the voltage and the current of the second current and the cross current generated by the respective field currents If (P) and If (S). For this reason, when the cross current protection relay 7 operates, it is not possible to understand the cause of the operation, and it takes time to investigate the cause at the time of an accident, and there is a problem that appropriate measures cannot be taken. .

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. Whether the cause of the cross current is caused by the phase difference between the outputs from the two generators, or the variation of the respective field currents. It is an object of the present invention to obtain a cross flow protection device for a compound type turbine generator capable of monitoring whether or not the generation has occurred.

[0007]

A cross flow protection device for a compound type turbine generator according to the present invention detects a phase difference between outputs generated from a first generator and a second generator. Phase difference detecting means, phase difference monitoring means for monitoring whether or not the phase difference exceeds a predetermined value; detecting field currents of the first generator and the second generator; And a field current monitoring means for monitoring whether or not the cross current has exceeded a predetermined value.

According to a second aspect of the present invention, there is provided a cross flow protection device for a compound type turbine generator, comprising: an output current detecting means for detecting respective output currents generated from a first generator and a second generator; Phase difference detecting means for detecting a phase difference according to the output current; phase difference monitoring means for monitoring whether the phase difference exceeds a predetermined value; and a first generator and a second generator, respectively. Field current detecting means for detecting a supplied field current, cross current detecting means for calculating a cross current according to a deviation of the field current, and a field current for monitoring whether or not the cross current exceeds a predetermined value Monitoring means.

According to a third aspect of the present invention, there is provided a cross flow protection device for a compound type turbine generator, comprising: an output current detecting means for detecting respective output currents generated from a first generator and a second generator; Field current detecting means for detecting field currents respectively supplied to the first and second generators, cross current detecting means for calculating a cross current according to the deviation of the field currents, and their output currents Deviation calculating means for subtracting the cross current from the deviation, phase difference monitoring means for monitoring whether the difference of the subtracted output current exceeds a predetermined value, and monitoring whether or not the cross current exceeds a predetermined value. And a field current monitoring means.

According to a fourth aspect of the present invention, there is provided a cross flow protection device for a compound type turbine generator, comprising: an output current detecting means for detecting respective output currents generated from a first generator and a second generator; Phase difference detection means for detecting a phase difference according to each output current, cross current detection means for calculating a cross current according to the phase difference, and phase difference monitoring for monitoring whether or not the phase difference exceeds a predetermined value Means, a deviation calculating means for subtracting the cross current from the deviation of the output current, and a field current monitoring means for monitoring whether or not the deviation of the subtracted output current exceeds a predetermined value.

According to a fifth aspect of the present invention, there is provided a cross flow protection device for a compound type turbine generator, wherein the first auxiliary power generation is provided directly connected to the respective rotating shafts of the first generator and the second generator. And second auxiliary generator, phase difference detecting means for detecting a phase difference between outputs generated from the first auxiliary generator and second auxiliary generator, and whether the phase difference exceeds a predetermined value. Phase difference monitoring means for monitoring whether or not
A field current detecting means for detecting a field current supplied to each of the first generator and the second generator; a cross current detecting means for calculating a cross current corresponding to a deviation of the field current; Field current monitoring means for monitoring whether or not a predetermined value has been exceeded.

According to a sixth aspect of the present invention, there is provided a cross flow protection device for a compound type turbine generator, wherein the first auxiliary power generation is provided directly connected to the respective rotating shafts of the first generator and the second generator. And a second auxiliary generator, phase difference detecting means for detecting a phase difference between outputs generated from the first and second auxiliary generators, and calculating a cross current according to the phase difference Cross-current detecting means, a phase difference monitoring means for monitoring whether the phase difference exceeds a predetermined value, and an output current for detecting respective output currents generated from the first generator and the second generator. It is provided with detection means, deviation calculation means for subtracting the cross current from the deviation of the output current, and field current monitoring means for monitoring whether or not the deviation of the subtracted output current exceeds a predetermined value.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 1 of the present invention. In the drawing, reference numeral 1 denotes a P generator (first generator), and 2 denotes an S generator. (Second generator), 3 is a P machine field circuit breaker for interrupting the field current If (P) supplied to the P machine generator 1, and 4 is a field supplied to the S machine generator 2. Current I
This is an S field breaker that cuts off f (S). 5 is provided in the power system of the P-machine generator 1, and is provided in the power system of the S-machine generator 2 for detecting the output current of the P-machine generator 1. The S generator 2
S current transformer (output current detection means) for detecting output current
It is. The configuration is the same as that of the conventional technology.

Reference numeral 11 denotes a current-voltage converter (output current detecting means) for converting the output current detected by the P-machine current transformer 5 into a voltage value, and 12 denotes an output current detected by the S-machine current transformer 6 Is a current-to-voltage converter (output current detecting means) for converting the into a voltage value. Reference numeral 13 denotes the current-voltage converters 11, 1
2. A phase difference detector (phase difference detecting means) for detecting a phase difference between output currents generated by the P-machine generator 1 and the S-machine generator 2 according to the voltage values corresponding to the respective output currents converted by the power generator 2. ), 14 compares the phase difference b detected by the phase difference detector 13 with a predetermined value, and shuts off the alarm or the P-field magnetic circuit breaker 3 and the S-field magnetic circuit breaker 4. It is a phase difference monitor (phase difference monitoring means).

A current-voltage converter 15 detects a field current If (P) supplied to the P-machine generator 1 and converts the field current If (P) into a voltage value (field current detection). Means, 16 is a field current If supplied to the S generator 2
(S) is a current-voltage converter (field current detecting means) for detecting the field current If (S) into a voltage value. 1
Reference numeral 7 denotes a field current If (P) and a field current If converted by the current / voltage converters 15 and 16, respectively.
A deviation calculator (cross current detecting means) for calculating a deviation from (S); a cross flow converter (cross current detecting means) for calculating a cross current corresponding to the deviation calculated by the deviation calculator 17;
Reference numeral 19 denotes a field current monitor that compares the cross current calculated by the cross current converter 18 with a predetermined value and interrupts the alarm or the P field circuit breaker 3 and the S field field circuit breaker 4. (Field current monitoring means).

Next, the operation will be described. When the P-motor generator 1 and the S-motor generator 2 are rotated by the prime mover, the P-motor generator 1 and the S-motor generator 2 have approximately the same rotation speed at about 50% of the rated rotation speed when the plant is started. , The P field breaker 3 and the S field breaker 4 are sequentially or simultaneously turned on. As a result, a voltage is generated between the P-machine generator 1 and the S-machine generator 2, and the two P-machine generators 1 and the S-machine generator 2
Goes to the synchronization state. However, two P generators 1 and S
In the case where the motor generator 2 is operated in a state where the phases are separated from each other, and when the field current If (P) and the field current If (S) vary, the two generators Crossflow occurs in

In the first embodiment shown in FIG. 1, output currents of P-machine generator 1 and S-machine generator 2 detected by P-machine current transformer 5 and S-machine current transformer 6 are converted to current-voltage converters. 1
The voltage is converted into a voltage value by 1 and 12, and the phase difference detector 13 detects a phase difference b of the output current generated from the P-machine generator 1 and the S-machine generator 2. If the phase difference b exceeds a predetermined value set in advance, the two generators are operated in an asynchronous state in which the phases are shifted from each other. The magnetic circuit breaker 3 and the S field magnetic circuit breaker 4 are cut off.

Further, the current-voltage converters 15 and 16
The field current If (P) and the field current If (S) supplied to the P-machine generator 1 and the S-machine generator 2 are converted into voltage values, and these deviations are calculated by the deviation calculator 17. , Is converted by a cross current converter 18 into a cross current value corresponding to the deviation. This cross current value corresponds to a field current deviation c between the field current If (P) and the field current If (S).
The cross current value is compared with a predetermined value by the field current monitor 19, and the alarm or the P machine field circuit breaker 3 and the S machine field circuit breaker 4 are cut off.

As described above, in the first embodiment, when an alarm or the P-field magnetic circuit breaker 3 and the S-field magnetic circuit breaker 4 are interrupted by the phase difference monitor 14, It can be recognized that it is caused by the phase difference between the outputs from the two generators, and the field current monitor 19 turns off the alarm or the P machine field circuit breaker 3 and the S machine field circuit breaker 4. In this case, it can be recognized that the cause of the cross current is caused by the variation of the field current. The configuration of the first embodiment is effective for the P-type generator 1 and the S-type generator 2 of the excitation type except the brushless excitation type. Further, in the first embodiment, the P machine current transformer 5 and the S machine current transformer 6 are provided, but a P machine transformer and an S machine transformer may be provided.

Embodiment 2 FIG. 2 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 2 of the present invention. In the figure, reference numeral 20 denotes a current detected by the current transformer 5 of the P machine and the current transformer 6 of the S machine. A current-voltage converter (deviation calculating means) 21 for converting the deviation of the output current into a voltage value is a deviation calculator for subtracting the cross current calculated by the cross current converter 18 from the voltage value converted by the current-voltage converter 20. (Deviation calculating means). The other configuration is the same as that of the first embodiment, and the description thereof will not be repeated.

Next, the operation will be described. In the first embodiment, the phase difference detector 13 detects the phase difference b of the output currents generated from the P-machine generator 1 and the S-machine generator 2, but in the second embodiment, the current-voltage converter 20 converts the output current deviation detected by the P-machine current transformer 5 and the S-machine current transformer 6 into a voltage value.
By subtracting the cross current calculated by the cross current converter 18 from the voltage value converted by the current / voltage converter 20 by 1, the deviation output from the deviation calculator 21 is not due to the variation of the field current, This can be regarded as being caused by the phase difference b.

As described above, in the second embodiment, as in the first embodiment, the cause of the cross current is caused by the phase difference between the outputs from the two generators. Can be recognized as being caused by the variation of. Further, compared to the first embodiment, there is no need to provide the phase difference detector 13, and the configuration can be simplified.

Embodiment 3 FIG. FIG. 3 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 3 of the present invention. In the figure, reference numeral 22 denotes a cross flow according to the phase difference detected by the phase difference detector 13. The cross current converter (cross current detecting means) 23 is a deviation calculator (23) for subtracting the cross current calculated by the cross current converter 22 from the deviation of the voltage values obtained by converting the output current of each generator by the current-voltage converters 11 and 12. Deviation calculating means). The other configuration is the same as that of the first embodiment, and the description thereof will not be repeated.

Next, the operation will be described. In the first embodiment, the current-voltage converter 15,
16, the respective field currents If (P)
And the field current If (S) are calculated, and the cross current converter 1
8, the cross current corresponding to the deviation calculated by the deviation calculator 17 is calculated. In the third embodiment, the detection of the field current If (P) and the field current If (S) is stopped. The cross current converter 22 converts the phase difference detected by the phase difference detector 13 into a cross current,
3, the output current of each generator is converted by the current-voltage converters 11 and 12 from the deviation of the voltage value.
By subtracting the cross current calculated by the above, it can be considered that the deviation output from the deviation calculator 22 is not caused by the phase difference b but is caused by the variation of the field current c.

As described above, in the third embodiment, as in the first embodiment, the cause of the cross current is caused by the phase difference between the outputs from the two generators. Can be recognized as being caused by the variation of. Further, compared with the first embodiment, there is no need to provide the current-voltage converters 15 and 16, and the configuration can be simplified.

Embodiment 4 FIG. 4 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 4 of the present invention. In the drawing, reference numeral 24 denotes a P machine provided directly connected to the rotating shaft of the P machine generator 1. An auxiliary generator (first auxiliary generator) 25 is an S auxiliary generator (second auxiliary generator) provided directly connected to the rotating shaft of the S generator 2. The other configuration is the same as that of the first embodiment, and the description thereof will not be repeated.

Next, the operation will be described. In the first embodiment, the output currents detected by the current transformers P and 5 are converted into voltage values by the current-voltage converters 11 and 12, and the phase difference is detected in accordance with the voltage values. Although the phase difference is detected by the device 13, in the fourth embodiment, a P machine auxiliary generator 24 and an S machine auxiliary generator 25 directly connected to the rotating shafts of the P machine generator 1 and the S machine generator 2 are provided. By directly taking the voltage or current output of the P-machine auxiliary generator 24 and the S-machine auxiliary generator 25 into the phase difference detector 13,
The phase difference between the outputs from the P-machine auxiliary generator 24 and the S-machine auxiliary generator 25 is detected.

As described above, in the fourth embodiment, as in the first embodiment, the cause of the cross current is caused by the phase difference between the outputs from the two generators. Can be recognized as being caused by the variation of. Also, compared to the first embodiment, there is no need to provide the P-machine current transformer 5, the S-machine current transformer 6, and the current-voltage converters 11 and 12, and the P-machine auxiliary generator 24 and the S-machine auxiliary generator Since the outputs of 25 can be directly taken into the phase difference detector 13, the phase difference detection accuracy can be improved.

Embodiment 5 FIG. 5 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 5 of the present invention. In FIG. 5, reference numeral 26 denotes a P-type current transformer 5 and an S-type current transformer 6. It is a current-voltage converter (deviation calculating means) for converting the deviation of the output current into a voltage value. The other configurations are the same as those of the third and fourth embodiments, and the description thereof will not be repeated.

Next, the operation will be described. In the fourth embodiment, the current-voltage converters 15 and
16, the respective field currents If (P)
And the field current If (S) are calculated, and the cross current converter 1
8, the cross current corresponding to the deviation calculated by the deviation calculator 17 is calculated. In the fifth embodiment, the current-voltage converter 26 detects the cross current by the P-machine current transformer 5 and the S-machine current transformer 6. The deviation of these output currents is converted into a voltage value, and thereafter, the phase difference detected by the phase difference detector 13 by the cross current converter 22 is converted into a cross current, as in the third embodiment. By subtracting the cross current calculated by the cross current converter 22 from the voltage value obtained by converting the deviation of the output current by the current / voltage converter 26 by the calculator 23, the deviation output from the deviation calculator 23 depends on the phase difference b. Instead, it can be considered that it is caused by the variation of the field current c.

As described above, in the fifth embodiment, as in the first embodiment, the cause of the cross current is caused by the phase difference between the outputs from the two generators. Can be recognized as being caused by the variation of. Further, compared with the first embodiment, there is no need to provide the current-voltage converters 15 and 16, and the configuration can be simplified. Further, since it is not necessary to provide the current-voltage converters 11 and 12, the outputs of the P-machine auxiliary generator 24 and the S-machine auxiliary generator 25 can be directly taken into the phase difference detector 13, so that the phase difference detection accuracy is improved. Can be enhanced.

[0032]

As described above, according to the first aspect of the present invention, the phase difference detecting means for detecting the phase difference between the outputs generated from the first generator and the second generator, and Phase difference monitoring means for monitoring whether the phase difference exceeds a predetermined value,
A cross current detecting means for detecting a field current of the first generator and the second generator and calculating a cross current according to a deviation of the field current, and monitoring whether or not the cross current exceeds a predetermined value; And the phase difference monitoring means can recognize that the cause of the cross current is caused by the phase difference between the outputs from the two generators. By this means, there is an effect that it is possible to recognize that the cause of the cross current is caused by the variation of the respective field currents.

According to the second aspect of the present invention, the output current detecting means for detecting the respective output currents generated from the first generator and the second generator, and the phase difference is determined according to the output current. Phase difference detection means for detecting, a phase difference monitoring means for monitoring whether or not the phase difference exceeds a predetermined value;
Current detection means for detecting the field current supplied to each of the generator and the second generator, a cross current detection means for calculating a cross current according to the deviation of the field currents, And the field current monitoring means for monitoring whether or not the cross current has been exceeded, so that the phase difference monitoring means determines that the cause of the cross current is caused by the phase difference between the output currents from the two generators. In addition to being able to recognize, there is an effect that the field current monitoring means can recognize that the cause of the cross current is caused by the variation of each field current.

According to the third aspect of the invention, output current detecting means for detecting output currents generated from the first generator and the second generator, respectively, and the first generator and the second generator. Field current detection means for detecting the field current supplied to the generator, cross current detection means for calculating a cross current in accordance with the deviation of the field current, and deviation calculation for subtracting the cross current from the deviation of the output current Means, phase difference monitoring means for monitoring whether the difference of the subtracted output current exceeds a predetermined value, and field current monitoring means for monitoring whether the cross current exceeds a predetermined value. , It is possible to recognize whether the cause of the cross current is caused by the phase difference between the outputs from the two generators or by the variation of the respective field currents. Means It is not necessary to kick, there is an effect that the configuration can be simplified.

According to the fourth aspect of the present invention, the output current detecting means for detecting the respective output currents generated from the first generator and the second generator, and the phase difference corresponding to the respective output currents , A cross current detecting means for calculating a cross current according to the phase difference, and a phase difference monitoring means for monitoring whether or not the phase difference exceeds a predetermined value,
A deviation calculation means for subtracting the cross current from the deviation of the output current and a field current monitoring means for monitoring whether or not the deviation of the subtracted output current exceeds a predetermined value. Can be recognized as being caused by the phase difference between the outputs from the two generators or due to variations in the respective field currents, and there is no need to provide field current detection means. There is an effect that the configuration can be simplified.

According to the fifth aspect of the present invention, the first auxiliary generator and the second auxiliary generator are provided directly connected to the respective rotating shafts of the first generator and the second generator. ,
Phase difference detecting means for detecting a phase difference between outputs generated from the first auxiliary generator and the second auxiliary generator, and phase difference monitoring means for monitoring whether the phase difference exceeds a predetermined value. Current detecting means for detecting a field current supplied to each of the first generator and the second generator, a cross current detecting means for calculating a cross current according to a deviation of the field currents, And a field current monitoring means for monitoring whether or not the current exceeds a predetermined value. Therefore, it is determined whether the cause of the cross current is caused by the phase difference between the outputs from the two generators. It is possible to recognize whether the current is generated due to the variation of the field current, and it is not necessary to provide an output current detecting means.
Since the output of the auxiliary generator can be directly taken into the phase difference detecting means, there is an effect that the phase difference detection accuracy can be improved.

According to the sixth aspect of the present invention, the first auxiliary generator and the second auxiliary generator are provided directly connected to the respective rotating shafts of the first generator and the second generator. ,
A phase difference detecting means for detecting a phase difference between outputs generated from the first auxiliary generator and the second auxiliary generator, a cross current detecting means for calculating a cross current in accordance with the phase difference; Phase difference monitoring means for monitoring whether or not a predetermined value has been exceeded; output current detection means for detecting output currents generated from the first generator and the second generator; A deviation calculating means for subtracting the cross current and a field current monitoring means for monitoring whether or not the deviation of the subtracted output current exceeds a predetermined value are provided. This can be recognized as being caused by the phase difference between the outputs from the IGBTs or by the variation of the respective field currents. Further, there is no need to provide a field current detecting means, and the configuration can be simplified. Furthermore, the first auxiliary generator and the second
Since the output of the auxiliary generator can be directly taken into the phase difference detecting means, there is an effect that the phase difference detection accuracy can be improved.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 1 of the present invention.

FIG. 2 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 2 of the present invention;

FIG. 3 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 3 of the present invention.

FIG. 4 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 4 of the present invention.

FIG. 5 is a circuit configuration diagram showing a cross flow protection device for a compound type turbine generator according to Embodiment 5 of the present invention.

FIG. 6 is a circuit configuration diagram showing a conventional cross flow protection device for a compound turbine generator.

[Explanation of symbols]

1 P machine generator (first generator), 2 S machine generator (second generator), 5 P machine current transformer (output current detecting means),
6 S machine current transformer (output current detection means), 11, 12 current-voltage converter (output current detection means), 13 phase difference detector (phase difference detection means), 14 phase difference monitor (phase difference monitoring means) , 15, 16 current-voltage converter (field current detecting means), 17 deviation calculator (cross current detecting means), 18, 2
2 Cross current converter (cross current detection means), 19 field current monitor (field current monitoring means), 20, 26 current-voltage converter (deviation calculation means), 21, 23 deviation calculator (deviation calculation means), 24 P machine auxiliary generator (first auxiliary generator),
25 S auxiliary generator (second auxiliary generator).

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H02H 7/06 H02J 3/00-3/50 H02P 9/00-9/48

Claims (6)

(57) [Claims] 1. A phase difference detecting means for detecting a phase difference between outputs generated from a first generator and a second generator, and whether a phase difference detected by the phase difference detecting means exceeds a predetermined value. Phase difference monitoring means for monitoring whether or not the cross current is detected, cross current detection means for detecting field currents of the first generator and the second generator, and calculating a cross current according to a deviation of the field currents; A cross flow protection device for a cross-compound type turbine generator, comprising: a field current monitoring means for monitoring whether or not the cross flow calculated by the cross current detection means exceeds a predetermined value. 2. An output current detecting means for detecting respective output currents generated from the first generator and the second generator, and the output current detecting means detects the output currents according to the respective output currents detected by the output current detecting means. Phase difference detecting means for detecting a phase difference between output currents generated from the first generator and the second generator, and determining whether or not the phase difference detected by the phase difference detecting means has exceeded a predetermined value. Phase difference monitoring means for monitoring, field current detection means for detecting a field current supplied to each of the first generator and the second generator,
A cross current detecting means for calculating a cross current corresponding to a deviation of the field currents detected by the field current detecting means; and a field monitoring means for monitoring whether or not the cross current calculated by the cross current detecting means exceeds a predetermined value. A cross flow protection device for a cross-compound type turbine generator comprising a current monitoring means. 3. An output current detecting means for detecting respective output currents generated from the first generator and the second generator, and supplied to the first generator and the second generator, respectively. Field current detection means for detecting a field current, a cross current detection means for calculating a cross current in accordance with the deviation of the field currents detected by the field current detection means, and a cross current detection means for detecting the cross current. Deviation calculating means for subtracting the cross current calculated by the cross current detecting means from the deviation of the output currents, and phase difference monitoring means for monitoring whether the deviation of the output current subtracted by the deviation calculating means exceeds a predetermined value. And a field current monitoring means for monitoring whether or not the cross current calculated by the cross current detection means exceeds a predetermined value. A cross flow protection device for a cross-compound turbine generator. 4. An output current detecting means for detecting respective output currents generated from the first generator and the second generator, and the output current detecting means detects the output current based on the respective output currents detected by the output current detecting means. Phase difference detection means for detecting a phase difference between output currents generated from the first generator and the second generator, and cross current detection for calculating a cross current according to the phase difference detected by the phase difference detection means Means, a phase difference monitoring means for monitoring whether or not the phase difference detected by the phase difference detection means exceeds a predetermined value; and a cross current detection means based on a deviation of the output currents detected by the output current detection means. And a field current monitoring means for monitoring whether or not the deviation of the output current subtracted by the deviation calculation means exceeds a predetermined value. Cross-flow protection device for compound turbine generators. 5. A first auxiliary generator and a second auxiliary generator provided directly connected to respective rotating shafts of the first generator and the second generator, and the first auxiliary generator And phase difference detection means for detecting a phase difference between outputs generated from the second auxiliary generator, and phase difference monitoring means for monitoring whether or not the phase difference detected by the phase difference detection means has exceeded a predetermined value. Field current detecting means for detecting a field current supplied to each of the first generator and the second generator, and a deviation of the field currents detected by the field current detecting means. A crossflow protection device for a cross-compound type turbine generator, comprising: a crossflow detection means for calculating a corresponding crossflow, and a field current monitoring means for monitoring whether or not the crossflow calculated by the crossflow detection means exceeds a predetermined value. . 6. A first auxiliary generator and a second auxiliary generator directly connected to respective rotating shafts of the first generator and the second generator, and the first auxiliary generator And a phase difference detecting means for detecting a phase difference of an output generated from the second auxiliary generator; a cross current detecting means for calculating a cross current in accordance with the phase difference detected by the phase difference detecting means;
Phase difference monitoring means for monitoring whether or not the phase difference detected by the phase difference detection means has exceeded a predetermined value; and output currents generated from the first generator and the second generator, respectively. Output current detection means for detecting, deviation calculation means for subtracting the cross current calculated by the cross current detection means from the deviation of the output currents detected by the output current detection means, and output current of the output current subtracted by the deviation calculation means. A cross flow protection device for a cross-compound type turbine generator, comprising: a field current monitoring means for monitoring whether the deviation exceeds a predetermined value.