JPH07170798A - Abnormality diagnositic method for exciting equipment for synchronous machine - Google Patents

Abstract

PURPOSE:To remarkably improve the reliability of abnormality diagnosis of an exciting equipment for synchronous machines, by performing comprehensive diagnoses based on comparison with and deviation from a wide variety of signals different in detection principle and synthesized equivalent quantities. CONSTITUTION:In a controller for an exciting equipment for synchronous machines, effective values V1, V2, V3 of three-phase voltage are detected from synchronous generator terminal voltage taken from PT, and a median VN is obtained through comparison of the effective values. When the deviation of the median VN from any of the effective values V1, V2, V3 exceeds a certain value DELTAVepsilon, unbalanced phase voltage 21 is detected. Effective values I1, I3 of one- and three-phase current are detected from synchronous generator terminal current taken from CT3. A PT system anomaly 20 is diagnosed for the reason that 'no occurrence of system accident and balanced current' 22 is detected by reason of the fact that one or both of I1 and I3 are below a certain value Iepsilon and the deviation between them is a certain value DELTAIepsilon or below.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an abnormality diagnosing method for an exciting device for a synchronous machine, and more particularly to an abnormality diagnosing method for detecting an abnormality in a signal detection system, an abnormality in a control controller, an abnormality in switching between a pumping mode and a power generation mode in pumped hydro. .

[0002]

2. Description of the Related Art A synchronous machine exciter is basically composed of an analog signal detection circuit and a thyristor gate control circuit. If there is a failure in the synchronous machine exciter, it must be immediately switched to the standby side or the operation must be stopped to repair the failure. Conventionally, for example, JP-A-56-132200 and JP-A-56-1 have been used for this failure determination.
23800 and the like. This discriminator is given the same input signal as the actual circuit, and the discriminant is basically 2 out of 3
The three signals are compared with each other according to the above logic, and one different signal source is determined as a failure.

[0003]

However, conventionally, a synchronous machine excitation device is an analog type, and an input signal the same as this is applied to make a determination, and a plurality of various detection signals are combined to make a comprehensive detection. It was not a diagnosis and was not reliable.

The object of the present invention is to make it possible to dramatically improve reliability by making a comprehensive diagnosis by comparing equivalent amounts synthesized with signals having different detection principles, deviations, and the like. It is easy and economical.

[0005]

The above-mentioned object is to detect the three-phase voltage effective value from the synchronous machine terminal voltage taken in from the instrument transformer PT in the synchronous machine exciter and to determine the effective voltage value of each phase. A phase voltage imbalance is detected when a deviation of a certain value or more among the deviations between the intermediate value obtained by comparison and each phase voltage effective value occurs, and 1 is detected from the synchronous machine terminal current fetched from the current transformer CT. Detect the effective value of 3-phase current,
At least one of the effective values of the phase current is less than a certain value and the deviation between the two is less than a certain value.
This is achieved by diagnosing an abnormality in the meter transformer PT system when the current balance is detected.

Further, the field circuit breaker closed state has passed for a certain period of time or more, and the instantaneous rate of change of each phase voltage is detected from the synchronous machine terminal voltage taken in from the instrument transformer PT, and the instantaneous value of each phase voltage is detected. This is achieved by diagnosing an AC signal input system abnormality when it is detected that the rate of change has not changed for a certain time or longer.

Further, the three-phase voltage effective value is detected from the synchronous machine terminal voltage fetched from the instrument transformer PT, and the 1.3-phase current effective value is detected from the synchronous machine terminal current fetched from the current transformer CT. Current imbalance is detected by the fact that all the phase voltage effective values are above a certain value and the deviation of the previous 1.3-phase current effective value is above a certain value for a certain period of time,
Or field diverted detects current transformer from the field current field current I _FDC from I _fAC the transducer, the field current I _fAC either the 1.3-phase current effective value is less than or equal to a predetermined value Since the deviation of the field currents I _fAC and I _fDC is not less than a certain value and is less than a certain value for a certain period of time, 1.3 phase C
This is achieved by diagnosing a CT system abnormality of the current transformer when the T simultaneous disconnection is detected.

Further, the field circuit breaker is closed for a certain period of time, and the PT system is normal and the diagnostic method according to claim 1
CT system normality is detected by the diagnostic method described in 1., the internal induced voltage of the synchronous machine is detected from the synchronous machine terminal voltage and terminal current taken from the instrument transformer PT and the current transformer CT, and the current transformer for field current is detected. From the field current I _fAC from the converter and the field current I _fDC from the converter, and the intermediate value obtained by comparing the internal induced voltage with the field currents I _fAC and I _fDC and I _fAC.
Or , if the deviation from I _fDC is more than a certain value, I
_This is achieved by diagnosing an _fAC system abnormality or an _IfDC system abnormality.

Further, when the synchronous machine terminal voltage taken in from the instrument transformer PT is a certain value or more, the control controller AVR
An AVR abnormality is diagnosed when the output continues the voltage increase command for a certain period of time, or when the AC circuit breaker 52G is closed and the terminal voltage is below a certain value and the AVR output continues the voltage reduction command for a certain period of time. Achieved by

Further, in pumped storage power generation, a transformer P for an instrument is used.
The frequency is detected from the terminal voltage of the synchronous generator taken in from T, and that the AC circuit breaker 52G is open and the terminal voltage is equal to or higher than a certain value and the frequency is equal to or less than a negative certain frequency for a certain period of time. It is achieved by diagnosing the power generation / pumping water switching abnormality.

[0011]

The abnormality diagnosis of the synchronous machine excitation device of the present invention is as follows.
Electricity of voltage, current, active power, reactive power and frequency is detected from the synchronous machine terminal, and electric quantities of field voltage and field current are detected from the synchronous machine field side. Comprehensive diagnostic processing is performed by the logic of the combination of the detected signals, comparison with the synthesized equivalent amount, deviation and the like. This enables _diagnosis of PT system abnormality, CT system abnormality, AC signal input system abnormality, field current I _fAC system abnormality, field current I _fDC system abnormality, AVR system abnormality, power generation / pumping water switching abnormality, and the like. .

[0012]

EXAMPLES The present invention will be described below with reference to examples. Figure 1
Shows an overall configuration of a synchronous machine excitation device according to an embodiment of the present invention.
The terminal voltage of the synchronous generator 1 is stepped down via the instrument transformer PT2 and input to the signal detection circuit 6. Similarly, the terminal current is input to the signal detection circuit 6 via the current transformer CT3.
Further, the field current of the synchronous generator 1 is CT4 for field current detection.
I _fAC via the converter 5 and I _fDC via the converter 5 into the signal detection circuit 6, respectively. Each input signal is a signal detection circuit 6
Is sent from the control controller AVR7 to the controller AVR7, and the value is used as a state quantity to perform constant voltage control, limit control, and other calculations. The control signal is input to the thyristor gate pulse generator 8 to change and control the firing angle of the thyristor 9, and the synchronous generator 1
The field current is changed to control the generator terminal voltage at a constant level. Further, the controller AVR7 performs abnormality detection for each part along with this control. In FIG. 1, 10 is an excitation transformer, 11 is a field breaker, 12 is a main transformer, and 13 is an AC breaker.

FIG. 2 shows a block diagram of a PT system abnormality 20 diagnosis process for detecting an abnormality in the PT 2 or the signal detection circuit 6. With respect to the AC instantaneous value signal as shown in FIG. 3, the instantaneous values v ₀ , v ₁ , and v ₂ at the time when the phase angle becomes 120 ° are set to 3
One is taken in and the single-phase effective value is detected by the formulas shown in the following formulas 1 and 2.

[0014]

[Equation 1]

[0015]

[Equation 2]

First, the phase voltage improper collision detection 21 is processed. As described above, the effective value of each phase voltage of the three-phase voltage is detected, and the values are set as V ₁ , V ₂ , and V _3, and are set as the effective value of V _{1, the} effective value of V _{2, and the} effective value of V ₃ (processing 211-21
3). Then, the value V _N located between V ₁ and V ₂ is selected (process 214). The following processing (processing 215 to 217) In each V _1, V _2, the effective value of V ₃ and V _N intermediate value deviation of | V _{N
-V 1 |, | V N -V} 2 |, | V N -V 3 | take, and comparing the predetermined value ΔVε each deviation. The phase voltage imbalance 21 is detected by outputting the logical sum of whether any deviation value of the comparison results is ΔVε or more by the 2out of 3 logic (process 218).

Next, the process of the system fault non-occurrence current balance detection 22 is performed. Similar to the voltage, the effective values I ₁ and I ₃ of 1.3-phase current of the generator terminal current input from the CT ₃ to the signal detection circuit 6 are detected and set (processes 221 and 22).
2). Then, the I ₁ effective value and the I ₂ effective value are compared with the constant value Iε (steps 223 and 224), and at least one of I ₁ and I ₃ is output as a logical sum if at least one is equal to or less than the constant value Iε ( Process 225). Also, the deviation between I ₁ and I ₃ | I ₁ −I ₃
| And compare the deviation with a constant value ΔIε (process 22
6) If ΔIε or less, it is detected that the output of the process 225 and the logical product (process 227) have been established, so that no system fault has occurred and the current is in the balanced state 22.

Since the phase voltage imbalance 21 is established and the system fault has not occurred / current balance 22 is established, the logical product of the both is established (process 23), and the PT system abnormality 20 is diagnosed.

FIG. 4 shows a block diagram of a diagnosis process for the abnormality 40 of the AC signal input system. The field breaker (41) 11 is closed (process 411), and after a certain time TD has passed (process 412), after the voltage is established, as shown in FIG. 3, t ₀ ,
Detecting the difference between two consecutive voltage instantaneous values v ₀ , v ₃ , v ₄ , v ₅ of t ₃ , t ₄ , t ₅ and the time when the phase angle is 90 ° as the rate of change of each phase voltage instantaneous value. Then, this is compared with the constant value ΔVε ₁ (process 413), and when ΔVε ₁ or less, the logical product is established (process 414). If this continues for a certain time or longer (process 415), the AC signal acquisition circuit abnormality 40 is diagnosed.

FIG. 5 shows a diagnostic processing block diagram of the CT system abnormality 50 for detecting the abnormality of the CT 3 or the signal detection circuit 6. First, the improper current 51 is detected. RMS value of each phase voltage V
It is compared whether ₁ , V ₂ and V ₃ are constant values V ε ₀ or more (processes 511 to 513), and when each phase voltage is V ε ₀ or more and the generator voltage is established, a logical product is established (process 514). )
And output. In addition, the 1.3-phase generator terminal current effective value I
_1, I ₃ of the deviations | I ₁ -I ₃ | By became by the comparison with a constant value Derutaaiipushiron (process 515) Derutaaiipushiron above, the logical product is established (processing 516), continue it certain period of time ( The current imbalance 51 is detected by performing the process 517).

Further, the CT simultaneous disconnection 52 for 1.3 phase is detected. Under the condition that the terminal current is output, each phase current effective value I
_{Since 1} and I ₃ are equal to or less than the constant value Iε ₀ (processing 521,
522), the logical sum is established (process 523), and occasionally the field current I _fDC detected from the field current transformer ₄ and the converter 5 are detected.
The detected field current I _FDC from the I _fAC constant value I
_When it is compared with _fAC ε (processing 524) and I _fAC is not _less than I _fAC ε, and the deviation | I _fAC −I _fDC | of I _fAC and I _fDC is compared with a constant value ΔI _f ε, (Process 52
5), the logical product is established (process 526), and the process 523 is performed.
A logical product with the output of (1) is established (process 528), and this continues for a predetermined time or longer (process 529), whereby the 1.3-phase CT simultaneous disconnection 52 is detected.

The CT system abnormality 50 is diagnosed when the logical sum (process 53) of either the current imbalance 51 or the CT simultaneous disconnection 52 for 1.3 phase is established.

FIG. 6 shows a diagnostic process of I _fAC system abnormality 61 for detecting abnormalities in the field current transformer 4 and the signal detection circuit 6 and I for detecting abnormalities in the converter 5 and the signal detection circuit 6.
The block diagram of the diagnostic process of the _fDC system abnormality 62 is shown. The field breaker 11 is closed (process 611), the voltage is established after a certain period of time (process 612), and there is no abnormality in the PT system due to the diagnosis process of FIG. In the diagnostic process of 5, the CT system is normal and the CT system is normal (process 614), and the logical product is established (processes 615 to 61).
6) and then, under this condition, the internal induced voltage | E of the synchronous generator 1 according to the following equations 3, 4, 5, 6 and 7.
(Vector) | is detected (process 617).

[0024]

[Equation 3]

[0025]

[Equation 4]

[0026]

[Equation 5]

[0027]

[Equation 6]

[0028]

[Equation 7]

Further, setting the field current I _FDC from the field current I _fAC and transducer 5 detected from the field diverting current transformer 4 (processing 618 to 619). Next, these intermediate values _Ifn are selected (process 620). Since | E (vector) | almost matches the field current I _f , the same comparison as in the case of PT system abnormality detection is performed between I _fAC and I _fDC directly detected from the field side, and the intermediate value is obtained. the value I _fN and I _fAC, or deviation of I _fN and I _FDC compares whether a fixed value [Delta] I _f epsilon ₁ or more (step 62
1, 622), which continues for a certain period of time (processes 623, 624), and is ANDed with the output of the process (process 616) (processes 625, 626) to establish the logic. It is diagnosed as I _fAC system abnormality 61 or I _fDC system abnormality 62.

FIG. 7 shows a block diagram of the diagnostic processing of the AVR abnormality detection 70 for detecting the abnormality of the operation of the controller AVR7 and the input signal to the thyristor gate pulse generator 8. When the generator terminal voltage VG is compared with a constant value VG _H (process 711) and is VG _H or more, the AVR output which is the input signal of the gate pulse generator 8 has a thyristor firing angle of 30 ° or less. If the command is a voltage increase command, a logical product is established (process 713) and when it continues for a fixed time (process 714), the AVR abnormality 70 is diagnosed. Alternatively, under the condition that the AC circuit breaker (52G) 13 is closed (process 715), V
G is equal to or less than a predetermined value VG _L (processing 717), and when the AVR output of the voltage lowering instruction to be thyristor firing angle 120 ° or more (the processing 716) logical product does not hold (process 718),
Even when it continues for a certain time (process 719), the logical sum is established (process 720), and the AVR abnormality 70 is diagnosed.

FIG. 8 shows a diagnostic processing block diagram of the power generation / pumping switch abnormality 80 in the case of pumped storage power generation. The frequency of the generator is the following formula 8, formula 9, formula 10, formula 11, and formula 12
To detect.

[0032]

[Equation 8]

[0033]

[Equation 9]

[0034]

[Equation 10]

[0035]

[Equation 11]

[0036]

[Equation 12]

In the above description, when the power generation mode is actually detected in the pumping mode, the 1.3 phases are exchanged, so the frequency is detected as a negative value. Therefore, the AC breaker 52G13 is open (process 811), the terminal voltage VG is equal to or higher than the constant value Vε ₁ (process 812), and the detection frequency f is a negative value equal to or lower than the constant value −fε under the condition that the frequency can be detected. When it becomes (process 813), the logical product is established (process 814), and it is diagnosed as the power generation / pumping water switching abnormality 80 because it continues for a certain time (process 815).

Any of the above abnormality diagnosis methods can be easily realized by software of the control controller AVR of the synchronous machine excitation device.

[0039]

As described above, according to the present invention, the amount of electricity such as voltage, current, active / reactive power and frequency from the synchronous machine terminal,
Various signals such as field voltage and field current are detected from the synchronous machine field side, the combination of the detected signals is compared and compared with the synthesized equivalent amount, and comprehensive diagnosis of the state quantity detection circuit is performed by the logic such as deviation. As a result, the reliability of diagnosis can be dramatically improved.

The abnormality diagnosis enables not only the signal capturing section and the signal detection circuit but also a logical abnormality diagnosis of the arithmetic output of the AVR, an abnormality diagnosis of pumping / power generation mode switching in pumped storage power generation, and the like.

Further, these diagnostic processes can be easily realized by the software of the controller for control, and the economy is extremely high.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an exciting device for a synchronous machine according to an embodiment of the present invention.

FIG. 2 is a block diagram of an abnormality diagnosis processing according to an embodiment of the present invention.

FIG. 3 is an output AC signal waveform diagram of the synchronous generator.

FIG. 4 is a block diagram of an abnormality diagnosis processing according to another embodiment of the present invention.

FIG. 5 is a block diagram of an abnormality diagnosis processing according to another embodiment of the present invention.

FIG. 6 is a block diagram of an abnormality diagnosis processing according to another embodiment of the present invention.

FIG. 7 is a block diagram of an abnormality diagnosis processing according to another embodiment of the present invention.

FIG. 8 is a block diagram of an abnormality diagnosis processing according to another embodiment of the present invention.

[Explanation of symbols]

1 ... Synchronous generator, 2 ... Transformer PT for instrument, 3 ... Current transformer C
T, 4 ... Field current transformer, 5 ... Converter, 6 ... Signal detection circuit, 7 ... Control controller, 8 ... Thyristor gate pulse generator, 9 ... Thyristor, 10 ... Excitation transformer,
11 ... Field breaker, 12 ... Main transformer, 13 ... AC breaker 52G, 20 ... PT system abnormality diagnosis, 40 ... AC signal input abnormality diagnosis, 50 ... CT system abnormality diagnosis, 61 ... If _AC system abnormality diagnosis, 62 ... If _DC system abnormality diagnosis, 7 ... AVR abnormality diagnosis, 8
0 ... Power generation / pumping water switching abnormality diagnosis.

Claims (9)

[Claims] 1. In a synchronous machine excitation device, a phase voltage imbalance is detected by diagnosing a three-phase voltage effective value from a synchronous machine terminal voltage taken from an instrument transformer PT, and the phase voltage imbalance is taken in from a current transformer CT. In an exciter for a synchronous machine, which is characterized by diagnosing an abnormal transformer PT system for an instrument by detecting a system fault and current balance by diagnosing the 1.3-phase effective current value from the synchronous machine terminal current. Abnormality diagnosis method. 2. The diagnosis of the three-phase voltage effective value is performed by detecting a deviation of a certain value or more among deviations between the intermediate value obtained by comparing the effective voltage values of the respective phases and the effective value of each phase voltage. Detecting voltage imbalance and diagnosing the 1.3-phase current effective value
3. Excitation of a system fault / current balance is detected when at least one of the effective values of the three-phase current is equal to or greater than a certain value and the deviation between the two is less than the certain value. Abnormality diagnosis method for equipment. 3. In a synchronous machine exciter, the rate of change of each phase voltage instantaneous value from the synchronous machine terminal voltage taken from an instrument transformer PT has been constant for a certain time after a certain time has passed with the field breaker closed. An abnormality diagnosing method for an exciting device for a synchronous machine, which is characterized by diagnosing an AC signal input system abnormality when it is detected that the change does not occur. 4. In a synchronous machine exciter, a three-phase voltage effective value from a synchronous machine terminal voltage taken from an instrument transformer PT and a 1.3 phase current from a synchronous machine terminal current taken from a current transformer CT. The current imbalance is detected by the combination diagnosis of the effective values, or the 1.3-phase current effective value and the field current I _fAC from the current transformer for the field current and the field current I from the converter.
_An abnormality diagnosis method for a synchronous machine exciter characterized by diagnosing a CT system abnormality in a current transformer when 1.3 simultaneous CT disconnections are detected by combination diagnosis with _fDC . 5. The combination diagnosis of the three-phase voltage effective value and the 1.3-phase current effective value is such that the three-phase voltage effective values are all above a certain value and the deviation of the 1.3-phase current effective value is above a certain value. 5. The abnormality diagnosing method in the synchronous machine exciting device according to claim 4, wherein the current imbalance is detected when the above condition continues for a certain period of time. 6. The 1.3-phase current effective value and field current I
_In the combination diagnosis of _fAC and I _fDC , any one of the 1.3-phase current effective values is a certain value or less, the field current I _fAC is a certain value or more, and the deviation between the field currents I _fAC and I _fDC is constant. C for 1.3 phase due to being below the value for a certain period of time
5. The abnormality diagnosing method in the synchronous machine exciting device according to claim 4, wherein T simultaneous disconnection is detected. 7. The synchronous machine exciter detects a normal PT system by the diagnostic system according to claim 1 and a normal CT system by the diagnostic system according to claim 4, after the field breaker is closed for a certain period of time. And the transformer PT and current transformer CT
Synchronous machine internal induced voltage from synchronous machine terminal voltage and terminal current taken in from and field current I from current transformer for field current
_If the deviation between the intermediate value obtained by comparing _fAC and the field current I _fDC from the converter and I _fAC or I _fDC is a certain value or more, it is diagnosed as I _fAC system abnormality or I _{f DC} system abnormality. An abnormality diagnosis method for a synchronous machine excitation device, which is characterized in that 8. In the synchronous machine excitation device, when the synchronous machine terminal voltage taken in from the instrument transformer PT is a certain value or more, the control controller AVR output continues the voltage increase command for a certain time, or the AC circuit breaker 52G. Is a closed state, the terminal voltage is below a certain value, and the AVR output continues the voltage lowering command for a certain period of time to diagnose an AVR abnormality. 9. An exciting device for a synchronous machine of pumped storage power generation,
The frequency is detected from the terminal voltage of the synchronous generator taken in from the instrument transformer PT, the AC circuit breaker 52G is in the open state, the terminal voltage is constant value or higher and the frequency is constant negative frequency or lower. An abnormality diagnosis method for a synchronous machine excitation device, which is characterized by diagnosing a power generation / pumping water switching abnormality by continuing for a period of time.