JP2000134790A - Protective relay - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately protect equipment against anomalous circumstances by providing an operation part, which changes operational settling of the antiphase current-operating time characteristics of a negative-phase sequence overcurrent relay based on the antiphase strength correction data of a generator calculated by heat radiation computation on the rotor temperature of the generator. SOLUTION: The field circuit of a field winding 2 is provided with a detector 22 for detecting the rotor temperature of a generator 1. In addition an operation part 23 is provided, which performs heat radiation computation on an antiphase current from a generator main circuit 3 and rotor temperature data for correcting the rotor temperature and outputs anthiphase strength correction data to change the operational settling of a negative-phase sequence overcurrent relay 21. The negative-phase sequence overcurrent relay 21 arbitrarily changes the operational settling values in its performance characteristics from before correction to after correction or from after correction to before correction, for example, according to antiphase strength correction data from the operation part 23. As a result, the generator 1 is protected appropriately and reliably, when an antiphase current is continued, as well as when an antiphase current is interrupted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protective relay for detecting an abnormality in a main circuit and a field circuit of a generator and protecting the generator and a transformer connected to the generator circuit. .

[0002]

2. Description of the Related Art There are various types of protection devices for protecting a generator and a transformer depending on their abnormal events and abnormal detection methods. The circuit configuration diagram of FIG. 9 shows a protective device based on reverse phase detection. The generator 1 is driven by a prime mover (not shown) and generates electric power by excitation of a field winding 2, and this electric power is supplied from a transformer 4 via a generator main circuit 3 to an external system or the like.

[0003] The armature electric quantity in the generator 1 during normal operation is synchronized with the rotor, and the rotor speed and the frequency of the armature electric quantity are exactly the same. That is, the electric quantity of the armature as viewed from the rotor side is always a constant invariant.

[0004] However, not only the generator main circuit 3 but also an interphase short-circuit accident or load imbalance in the power system causes a reverse phase component to occur, and the phase rotation becomes reverse to the normal phase component. The amount of reverse phase electricity observed from the child side is
This means that the motor rotates in the opposite direction at twice the synchronous speed. Due to the temperature rise due to overcurrent on the rotor core surface, slot wedge surface, and rotor bar of the generator 1,
Causes overheating.

Conventionally, as a reverse-phase protection for the generator 1, in order to protect the generator 1 and the transformer 4 connected to the generator 1 from the above-mentioned reverse-phase event, the generator main circuit 3 The reverse-phase current In is detected by the detector 5 and is protected by the reverse-phase overcurrent relay 6 which is a protection relay having the In ² t = K characteristic (t: operation time, K: constant) of the generator 1. are doing.

In the negative-phase overcurrent relay 6, the generator reverse-phase tolerance 7, the trip element setting value 8, and the alarm element setting value 9 are set with respect to the negative-phase current In and the operation time t. ing.

Therefore, when the negative-phase current In exceeds each set value, the negative-phase overcurrent relay 6 is determined to be abnormal and operates, and an alarm by an alarm device (not shown) is tripped with the alarm element set value 9 to trip. By shutting off the circuit breaker or reducing the load at the element set value 8, the generator 1 is safely protected with a generator reverse phase withstand capability of 7 or less. At this time, the transformer 4 connected to the generator 1 is also safely protected by stopping or decreasing the current.

FIG. 10 is a circuit diagram showing a protection device based on overexcitation detection. Here, the overexcitation event is caused by any cause in a system configured by the generator 1 and the transformer 4.
When the voltage / frequency (hereinafter, abbreviated as V / F) value of each of the devices increases, magnetic flux saturation occurs due to V / F overexcitation in the iron core, which is a magnetic circuit.

This is an event that causes eddy current generation and overheating of the iron core itself, and overheating due to eddy current generated in a nearby conductor structure due to increased leakage magnetic flux, thereby causing the generator 1 and the transformer 4 to operate. Due to overheating, accidents due to this overexcitation event may spread to the entire system in some cases.

As a method of this overexcitation protection, a voltage V and a frequency F of the generator main circuit 3 are detected by a detector 10 and a generator V / F is detected by an overexcitation relay 11 which is a protection relay.
The protection is performed based on the withstand voltage or the V / F withstand voltage of the transformer and the time (operating time) corresponding to the amount of heat accumulation as basic elements.

In the overexcitation relay 11, the generator V / F with respect to the V / F value and the operation time t as its operation characteristics.
A trip element setting value 8 and an alarm element setting value 9 are set together with the F tolerance 12 and the transformer V / F tolerance 13. Therefore, if the V / F detected by the detector 10 is less than the generator V / F tolerance 12 and the transformer V / F tolerance 13 and exceeds each set value, it is determined to be abnormal and the operation is performed. Then, the generator 1 and the transformer 4 are safely protected by performing an alarm by an alarm device (not shown) and shutting off the circuit breaker or reducing the load.

FIG. 11 is a circuit diagram showing a protection device based on overload detection. Here, the overload event is an event in which the generator 1, the transformer 4, and the in-house transformer 14 are overloaded due to the load state of the external system or, for example, the in-house system, which may cause a rise in the temperature of the equipment.

The electric power generated by the generator 1 is transferred to the generator main circuit 3
Through the transformer 4 and the in-house transformer 14 to the load in the external system and the in-house system (not shown), but the generator 1, the transformer 4 and the in-house transformer 14 are overloaded in the state of each load. In this case, the currents of the generator main circuit 3 and the station circuit are detected by the detector 15 in order to protect the generator 1, the transformer 4 and the station transformer 14.

The generator main circuit 3 detected by the detector 15
And the current of the internal circuit is taken into the overcurrent relay 16,
The overcurrent relay 16 has, as operating characteristics, a trip element setting value 8 along with an overload tolerance 17 of the generator 1, the transformer 4, and the in-house transformer 14 with respect to the current I and the time t (operating time).
Is settled.

Accordingly, when the current I is less than the overload withstand capability 17 and exceeds the trip element set value 8, the overcurrent relay 16 is determined to be abnormal and operates, and a breaker (not shown) is cut off or the load is reduced. By doing so, the generator 1, the transformer 4 and the on-site transformer 14 are safely protected.

FIG. 12 is a circuit diagram showing a protection device based on detection of a field ground fault. Here, the field ground fault event is usually used in a field circuit including the field winding 2 of the generator 1 without being grounded. Therefore, a ground fault at only one place in the field circuit does not cause any problem, but if a ground fault occurs at two different places, an overcurrent flows through the field winding 2 together with the field circuit, resulting in a large accident. Further, when a part of the field winding 2 is short-circuited, it is an event that magnetic unbalance or vibration occurs in the rotor of the generator 1.

As a method of protecting the field ground fault, a field current detector 18 and a detector 19 provided in a field circuit are used to detect a ground fault resistance in a field circuit of the generator 1 and a field relay serving as a protection relay. The field ground resistance is detected by relatively comparing the voltage drop of the internal resistance (constant) of the magnetic ground relay 20, and the generator 1 is protected by the field ground relay 20.

The field grounding relay 20 has a field grounding resistance Rg (detection sensitivity) and a field voltage Vf as operating characteristics.
, The trip element setting value 8 is set. Therefore, the field earth resistance Rg is set to the trip element set value 8
Is exceeded, the field grounding relay 20 is determined to be abnormal and operates, and the generator 1 is safely protected by interrupting a circuit breaker (not shown).

[0019]

In each of the above-mentioned various protective relays, abnormal behaviors of current, voltage, frequency and resistance, which are electrical abnormal factors, are detected, and the generator 1 or the transformer 4 is detected. By coordinating the permissible tolerance of heat radiation and the like on the equipment side such as the in-house transformer 14 and the protection (operation) characteristics of the protection relay, the generator 1 or the transformer 4
In addition, overheating protection of each device of the in-house transformer 14 is appropriately performed.

However, the permissible tolerance of each device changes depending on the temperature condition of the device or the surroundings and the deterioration condition of the insulator. On the other hand, with respect to the protection characteristics of each protection relay, since the set value is constant regardless of the situation, it is difficult to protect the equipment in a strict sense.

An object of the present invention is to correct the operation settling of the protection characteristics of various protective relays such as anti-phase and over-excitation, based on the permissible heat dissipation and the like of the generator and transformer connected to the same circuit. Accordingly, it is an object of the present invention to provide a protective relay device that appropriately protects each device in the event of an abnormal event.

[0022]

According to a first aspect of the present invention, there is provided a protective relay device comprising: a negative-phase overcurrent relay operated by a negative-phase current in a generator main circuit; A calculating unit for changing the operation setting of the negative-sequence current-operating time characteristic in the negative-sequence overcurrent relay from the negative-phase tolerance amount correction data of the generator based on the heat dissipation calculation of the rotor temperature.

The operation settling of the negative-sequence overcurrent relay is changed by the negative-phase tolerance correction data of the generator based on the heat dissipation calculation of the rotor temperature of the generator. Safely protected within the tolerance of reverse phase tolerance.

According to a second aspect of the present invention, there is provided a protection relay device comprising a negative-phase overcurrent relay operated by a negative-phase current in a generator main circuit, and a history calculation of a negative-phase current flowing through the generator main circuit. It is characterized by comprising a calculation unit for changing the operation setting of the negative-phase current-operation time characteristic in the negative-phase overcurrent relay from the negative-phase tolerance correction data of the generator. The operation setting of the reverse-sequence overcurrent relay is changed by the reverse-phase current correction data based on the history calculation of the negative-sequence current. Protected.

According to a third aspect of the present invention, there is provided a protective relay device that is connected to an overexcitation relay that operates by overexcitation based on the voltage and frequency of a generator main circuit, the temperature of the generator, and the generator circuit. A generator configured to change the operation setting of the overexcitation voltage and the frequency-operation time characteristic of the overexcitation relay from the overexcitation withstand correction data of the generator and the transformer that has been subjected to the radiation calculation based on the temperature of the transformer. .

From the temperature of the generator and the temperature of the transformer connected to the generator circuit, the operation settling of the over-excitation relay is changed by the over-excitation tolerance correction data of the generator and the transformer by heat radiation calculation. Generators and transformers whose over-excitation withstand capability has been reduced due to an increase in the over-excitation temperature are safely protected within the tolerance of the over-excitation withstand capability.

According to a fourth aspect of the present invention, there is provided a protective relay comprising an over-excitation relay which operates by over-excitation from the voltage and frequency of the generator main circuit, and a history of the voltage and frequency applied to the generator main circuit. A calculation unit for changing the over-excitation voltage and the operation setting of the frequency-operation time characteristic in the over-excitation relay from the over-excitation tolerance correction data of the transformer connected to the generator and the generator circuit by calculation. And

The operation setting of the over-excitation relay is changed by the over-excitation tolerance correction data based on the history calculation of the voltage and current due to over-excitation, so that the generator and the transformer whose over-excitation tolerance is reduced by over-excitation will It is safely protected within the tolerance of excitation tolerance.

According to a fifth aspect of the present invention, there is provided a protective relay comprising an overcurrent relay operated by an overcurrent in a generator main circuit, a stator winding temperature of the generator and a transformer connected to the generator circuit. And an operation unit for changing the operation setting of the relay current-operating time characteristic in the overcurrent relay from the overload withstand amount correction data based on the heat radiation calculation based on the temperature of the winding or the insulating oil, or both temperatures.

The heat radiation calculation is performed from the temperature of the stator core or the end of the stator core of the generator, or both, and the temperature of the windings of the transformer connected to the generator circuit or the temperature of the insulating oil, or both. The operation setting of the overcurrent relay is changed by the overload tolerance correction data of the generator and the transformer, and the generator and the transformer whose overload tolerance has decreased due to the rise of the temperature of the overload have the overload tolerance. Safely protected within tolerance.

According to a sixth aspect of the present invention, there is provided a protective relay device comprising: an overcurrent relay operated by an overcurrent in a generator main circuit; And an operation unit for changing an operation setting of a current-operation time characteristic in the overcurrent relay from overload tolerance correction data of a transformer connected to the generator circuit.

The operation settling of the overcurrent relay is changed by the overload tolerance correction data based on the history calculation of the overcurrent due to the overload, so that the generator and the transformer whose overload tolerance has been reduced due to the overload are subjected to the overload. Protected safely within tolerance of tolerance.

According to a seventh aspect of the present invention, there is provided a protective relay device comprising: a field grounding relay operated by a field grounding resistance in a field circuit of a generator; and a heat radiation of a rotor temperature obtained from the field circuit. It is characterized by comprising an operation unit for changing the operation setting of the field current-operation time characteristic in the field earth relay from the field earth resistance correction data calculated. The operation settling of the field grounding relay is changed by the field grounding resistance correction data of the generator by the heat radiation calculation of the rotor temperature of the generator. It is safely protected within the tolerance of the rotor capacity.

[0034] The protective relay device according to the present invention is characterized in that a field ground relay operated by a field ground resistance in a field circuit of a generator and a rotor temperature history obtained from the field circuit are stored. And a calculation unit for changing the operation setting of the field current-operation time characteristic in the field ground relay from the field ground resistance correction data obtained by the rotor withstand calculation.

The operation settling of the field grounding relay is changed by the field grounding resistance correction data of the generator based on the heat radiation calculation of the rotor temperature history of the generator. The machine is safely protected within its rotor capacity tolerance.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to the drawings. Note that the same components as those of the above-described related art are denoted by the same reference numerals, and detailed description thereof will be omitted. The first embodiment is a protection device according to claim 1, which is driven by a motor (not shown) in a generator 1 as shown in the circuit diagram of FIG. , And this power is supplied from a transformer 4 to an external system via a generator main circuit 3.

As a reverse-phase protection in the generator 1, a negative-phase current In is detected from the main circuit 3 of the generator. A reverse-phase overcurrent relay 21 is provided as a protection relay in which the element setting value 8 and the alarm element setting value 9 are set.

Further, a field current detector 18 is provided in the field circuit of the field winding 2 to detect the field current If and take out the field voltage Vf. From the field resistance R (R = V / I) by the magnetic voltage Vf, the generator 1
Is provided with a detector 22 for detecting the rotor temperature.

Further, based on the negative phase current from the generator main circuit 3 and the rotor temperature data detected by the detector 22,
And a calculation unit 23 that performs heat dissipation calculation for correcting the rotor temperature and outputs reverse phase tolerance correction data for changing operation setting of the reverse phase overcurrent relay 21. Further, in the negative-phase overcurrent relay 21, each operation set value in the operation characteristic is obtained by the negative-phase tolerance correction data from the arithmetic unit 23, for example, from "before correction" to "after correction" as shown by a white arrow. Changes to or vice versa are optional.

The change of the operation setting is performed in the case where the protection relay performs the above-mentioned reverse phase tolerance correction data.
There is a case where equivalent correction corresponding to the change of the operation setting in the protection relay is performed on the correction data.Hereinafter, all embodiments will be described using the former case as an example, but the same result is obtained in any case. Things.

Next, the operation of the above configuration will be described. When a negative-phase current flows through the generator 1, the negative-phase current In
Exceeds the set values in the negative-phase overcurrent relay 21, the negative-phase overcurrent relay 21 operates to perform alarm and protection.

At this time, the rotor temperature of the generator 1 rises due to the negative phase current. The rise in the rotor temperature is detected by the detector 22 and the temperature data is taken into the arithmetic unit 23. Then, the heat dissipation calculation of the rotor temperature is performed, and the reverse phase tolerance correction data corrected according to the reverse phase tolerance of the generator 1 at this time is output to the reverse phase overcurrent relay 21.

Here, when the temperature of the generator 1 rises due to the flow of the reverse phase current and the reverse phase resistance decreases, the reverse phase resistance correction data corresponding to the reduced reverse phase resistance is used to correct the reverse phase resistance. In the phase overcurrent relay 21, the generator reverse-phase withstand voltage 7, the trip element setting value 8, and the alarm element setting value 9 set in the operation characteristics are changed from "before correction" to "after correction" as indicated by white arrows. The operation time t is set to the operation time t ₁
And the operating value due to the reverse-phase current In is changed to a lower value.

Therefore, in the reverse-phase overcurrent relay 21,
When the negative-phase current In flowing through the generator 1 exceeds each of the set values changed to the “after correction”, it is determined that an abnormality has occurred. At the trip element set value 8, the circuit breaker is turned off or the load is reduced, thereby safely protecting the generator 1 having the reduced reverse phase withstand capability due to the rise in the rotor temperature.

After a certain period of time has elapsed after the negative-phase current has temporarily flowed, the rotor temperature of the generator 1 has decreased and approaches the steady-state temperature. In this case, the set values are changed in the direction opposite to the white arrow so that the operation time setting of the reverse-phase overcurrent relay 21 becomes longer, so that, of course, when the reverse-phase current is continuous, The generator 1 can be properly and reliably protected even if it is interrupted.

The second embodiment relates to claim 2 and is a protection device based on reverse phase detection, which is a modification of the first embodiment. Therefore, the same configuration, operation and effect as those of the first embodiment will be described. The description will be omitted, and different points will be described.
As shown in the circuit configuration diagram of FIG. 2, in the generator 1, power is supplied from a generator main circuit 3 to an external system.

Further, a detector 5 for detecting the reverse-phase current of the generator 1 from the generator main circuit 3 and a history of the reverse-phase current detected by the detector 5 are accumulated, so that the insulator of the generator 1 An operation unit 24 that outputs the reverse phase tolerance correction data corresponding to the deterioration is provided. Further, from the correction data of the reverse phase tolerance due to the deterioration of the insulator output from the calculation unit 24, the reverse phase protection for the generator 1 is performed. An element set value 8 and an alarm element set value 9 are set, and the reverse-phase overcurrent relay 21 of the protection relay is set.

Next, the operation of the above configuration will be described. When a negative-sequence current flows through the generator 1, the negative-sequence current value is measured by the detector 5, and the history of the measured negative-sequence current value is stored in the arithmetic unit 24, and the accumulated negative-sequence current is stored. A correction operation corresponding to the deterioration of the insulator of the generator 1 is performed based on the history.

Here, when the reverse-phase withstand capability of the generator 1 is reduced due to the flow of the reverse-phase current, the reverse-phase overcurrent relay is operated in accordance with the reverse-phase withstand capability correction data from the arithmetic unit 24.
In 21, the generator reverse phase tolerance 7, trip element setting value 8, and alarm element setting value 9 set in the operation characteristics are set.
Is changed from “before correction” to “after correction” as shown by a white arrow, the setting of the operation time t is shortened like the operation time t ₁ , and the operation value due to the reverse-phase current In is changed to be low. .

Therefore, in the reverse-phase overcurrent relay 21,
When the negative-phase current In flowing through the generator 1 exceeds each set value changed to the “after correction”, it is determined that there is an abnormality, an alarm is issued, and the generator 1 is safely protected.

The third embodiment relates to a third aspect of the present invention, which is a protection device based on overexcitation detection. As shown in the circuit diagram of FIG. 3, the generator 1 is driven by a prime mover (not shown) and has a magnetic field. Electric power is generated by exciting the winding 2, and this electric power is supplied from a transformer 4 to an external system via a generator main circuit 3. As over-excitation protection in the generator 1 and the transformer 4, an over-excitation relay 25 that operates at the voltage and frequency (V / F) of the generator main circuit 3 and protects the generator 1 and the transformer 4 is provided. Provided.

The operating characteristics of the overexcitation relay 25 include a generator V / F tolerance 12 and a transformer V / F tolerance 13 with respect to a V / F value and an operating time t, a trip element setting value 8 and an alarm. The element set value 9 has been set. Further, a field current detector 18 is provided in the field circuit of the field winding 2,
The field current If is detected and the field voltage Vf is taken out. From the field current If and the field resistance R (R = Vf / If) based on the field voltage Vf, the temperature due to overexcitation of the generator 1 is determined. It has a detector 26 for detecting.

Further, a detector 27 for detecting the temperature of the winding 4a of the voltage transformer 4 of the generator main circuit 3, the insulating oil for cooling the winding 4a and the iron core, or both, and the detector 27 Based on the temperature data of the main transformer 4 and the temperature data of the generator 1 detected by the detector 26 and the temperature data of the generator 1, a correction based on the V / F withstand capability of the generator 1 and the transformer 4 is calculated by a heat radiation calculation. And an arithmetic unit 28 that outputs excitation withstand amount correction data to the overexcitation relay 25.

The operation characteristics of the overexcitation relay 25 are changed from “before correction” to “after correction” as shown by a white arrow, for example, according to the correction data from the arithmetic unit 28.
Or the change in the opposite direction is optional.

Next, the operation of the above configuration will be described. When the generator 1 and the transformer 4 are overexcited,
Since the temperature of the core of the generator 1 and the temperature of the windings and the temperature of the insulating oil of the transformer 4 rise, these temperature data are taken into the detection operation unit 28 from the detectors 26 and 27 and the generator 1 The heat radiation calculation is performed on the V / F resistance of the iron core and the windings of the transformer 4.

Here, if the V / F tolerance of the generator 1 and the transformer 4 is reduced due to the overexcitation, the overexcitation relay according to the overexcitation tolerance correction data from the arithmetic unit 28.
At 25, the generator V /
The F tolerance 12 and the transformer V / F tolerance 13, the trip element setting value 8 and the alarm element setting value 9 are changed from "before correction" to "after correction" as indicated by white arrows, and the operation time t is set. Is shortened, and the operation value based on the V / F value is changed to a lower value.

Therefore, in the overexcitation relay 25, when the V / F value in the generator 1 and the transformer 4 exceeds each set value changed to “after correction”, it is determined that there is an abnormality, and an alarm is issued. Emit and safeguard.

Note that the overexcitation is temporary, and after a certain period of time, the temperatures of the generator 1 and the transformer 4 that have risen decrease and approach the steady temperature. In this case, the set values are changed in a direction opposite to the white arrow so as to lengthen the operation time setting of the overexcitation relay 25, so that not only when the overexcitation is continuous but also when the overexcitation is intermittent. The generator 1 and the transformer 4 are properly and reliably protected.

The fourth embodiment relates to claim 4, which is a protection device based on overexcitation detection and is a modification of the third embodiment. Therefore, the same configuration, operation and effect as those of the third embodiment will be described. Description is omitted. As shown in the circuit diagram of FIG. 4, the generator 1 supplies power to an external system.

As overexcitation protection in the generator 1 and the transformer 4, the voltage V and the frequency F (V) of the generator main circuit 3 are used.
/ F), and the voltage and frequency from the detector 10 are used to determine the generator 1
And an operation unit 29 for outputting overexcitation tolerance correction data for correcting the V / F tolerance due to deterioration of the insulator in the transformer 4.

Further, the generator 1 and the transformer 4 which operate at the V / F and change the operation set value according to the overexcitation tolerance correction data from the V / F tolerance due to the insulation deterioration outputted by the arithmetic unit 29. The over-excitation relay 25 is a protection relay for over-excitation protection.

Next, the operation of the above configuration will be described. When the generator 1 and the transformer 4 are overexcited,
The voltage and frequency are detected by the detector 10, and the history of the detected voltage and frequency is stored in the calculation unit 29. Further, the arithmetic unit 29 performs a deterioration correction calculation of the insulator based on the history of the stored voltage and frequency, and outputs the overexcitation tolerance correction data obtained by correcting the V / F tolerance of the generator 1 and the transformer 4 to the overexcitation relay. Output to 25.

Here, if the V / F tolerance of the generator 1 and the transformer 4 is reduced due to the overexcitation, the overexcitation relay is operated in accordance with the overexcitation tolerance correction data from the arithmetic unit 29.
In 25, the generator V / F withstand capability settled by its operating characteristics
12 and the transformer V / F tolerance 13, the trip element setting value 8 and the alarm element setting value 9 are changed from “before correction” to “after correction” as indicated by white arrows, and the setting of the operation time t is shortened to V. The setting value operated by the / F value is changed to a lower value.

Therefore, in the over-excitation relay 25, the V / F values in the generator 1 and the transformer 4 are different from the “after correction”.
If each set value changed to is exceeded, it is determined to be abnormal,
An alarm is issued and the generator 1 and the transformer 4 are safely protected.

The fifth embodiment is directed to a protection device for detecting an overload, wherein the generator 1 is driven by a prime mover (not shown) as shown in the circuit diagram of FIG. The power is generated by exciting the winding 2, and this power is supplied to the external system from the transformer 4 via the generator main circuit 3, and to the internal system by, for example, the internal transformer 14.

As an overload protection in the generator 1, the transformer 4 and the in-house transformer 14, it operates with the overload current detected from the generator main circuit 3, and its operation characteristics are as follows. An overcurrent relay 30, which is a protection relay in which a load withstand capacity 17 and a trip element setting value 8 are set, is provided.

Further, a detector 27 for detecting the temperature of the transformer winding 4a of the transformer 4, the insulating oil for cooling the transformer winding 4a and the iron core, or a temperature of both of them, A detector 31 for detecting the temperature of the insulating oil for cooling the transformer winding or the iron core and a detector 32 for detecting the temperature of the stator winding 1a of the generator 1 are provided.

Further, the overload current from the generator main circuit 3, the temperature of the generator 1 detected by the detector 32, the detector 27 and the detector 31, and the temperatures of the transformer 4 and the in-house transformer 14 are used. 1 and a calculation unit 33 that performs a heat radiation calculation for correcting the overload tolerance of the transformer 4 and the in-house transformer 14 and outputs the overload tolerance correction data to the overcurrent relay 30.

In the overcurrent relay 30, the operating characteristics are changed from “before correction” to “after correction” as shown by a white arrow, for example, according to the overload tolerance correction data from the arithmetic unit 33. Make a change in the opposite direction.

Next, the operation of the above configuration will be described. When an overload current flows through the generator 1, the transformer 4, and the station transformer 14, the temperatures of the stator winding 1a of the generator 1, the windings of the transformer 4, and the station transformer 14 rise, and the transformer 1 The insulating oil temperature of the transformer 4 and the station transformer 14 also increases.

This temperature rise is detected by the detector 32, the detector 27 and the detector 31, and the arithmetic unit 33
Performs a heat dissipation calculation on the overload capacity of the generator 1, the transformer 4, and the in-house transformer 14, and outputs the overload capacity correction data to the overcurrent relay 30. In the overcurrent relay 30, according to the overload tolerance correction data from the arithmetic unit 33, the trip element set value 8 is indicated by a white arrow together with the overload tolerance 17 of the generator 1 and the transformer 4 as indicated by a white arrow. changed from before "to" after correction ", to change short as operating time t ₁ to set the operating time t.

Therefore, in the overcurrent relay 30, when the current I flowing through the generator 1 and the transformer 4 exceeds the set value changed to the “after correction”, it is determined that the current is abnormal, and the By shutting down or reducing the load, the generator 1 and the transformer 4 whose overload withstand capability has decreased due to the temperature rise due to the overload.
And safeguard the in-house transformer 14.

When a certain period of time has passed after the overload, the detected temperatures of the generator 1 and the transformer 4 approach the steady-state temperature. Give instructions to extend the operating time. As a result, the generator 1 and the transformer 4 can be properly and reliably protected not only when the overload current is continuous but also when the overload current is interrupted.

The sixth embodiment relates to claim 6, which is a protection device based on overload detection, which is a modification of the fifth embodiment, and has the same structure, operation and effect as those of the fifth embodiment. Will not be described. As shown in the circuit diagram of FIG. 6, in the generator 1, the
Further, for example, power is supplied to the in-house system by the in-house transformer 14.

As an overload protection in the generator 1, the transformer 4 and the station transformer 14, the generator 1 operates with the overload current of the generator main circuit 3 and the station circuit. An overcurrent relay 30 which is a protection relay in which the overload capacity 17 and the trip element setting value 8 are set.
It has.

In addition, the generator main circuit 3 and the station transformer
Detector 15 for detecting overcurrent of 14 systems, and this detector 15
The history of the overload current from is stored, and the correction of the insulation deterioration is calculated based on the accumulated history of the overload current,
And an arithmetic unit 34 that outputs the overload tolerance correction data to the overcurrent relay 30.

Next, the operation of the above configuration will be described. When an overload current flows through the generator 1, the transformer 4, and the on-site transformer 14, the overload current is detected by the detector 15, and based on the overload current data, the calculation unit 34 determines the insulation based on the history of the overload current. The correction calculation of the overload tolerance from the deterioration of the object is performed, and the overload tolerance correction data is output to the overcurrent relay 30.

In the overcurrent relay 30, the generator 1 and the transformer 4
When the current I flowing through the in-house transformer 14 exceeds the set value changed to the “after correction”, it is determined that the current is abnormal, and the circuit breaker is cut off or the load is reduced, and the like. The generator 1, the transformer 4 and the on-site transformer 14 whose overload capability has been reduced due to insulation deterioration are safely protected.

The seventh embodiment relates to a protection device by detecting a field ground fault (field ground resistance), which is not shown in the generator 1 as shown in the circuit diagram of FIG. Driven by the prime mover, the power is generated by exciting the field winding 2, and this power is supplied to the external system via the generator main circuit 3.

The generator 1 is activated by a field ground current (field ground resistance) as a field ground protection, and a trip element set value 8 with respect to a ground fault current Ig and an operation time t is set as an operation characteristic. A field grounding relay 35 is provided as a protective relay. A field current detector 18 provided in a field circuit of the field winding 2;
Field current and field voltage from the
A detector 22 for detecting the rotor temperature of the generator 1 from (R = V / I) is provided.

Further, a calculating unit 36 for calculating heat radiation from the rotor temperature from the detector 22 and outputting field resistance correction data for correcting the field ground resistance to the field ground relay 35. It is composed of The field grounding relay
In 35, the operating characteristics can be changed from “before correction” to “after correction” as shown by a white arrow, and in the opposite direction, for example, as indicated by a white arrow, according to the field resistance correction data from the arithmetic unit 36. And

Next, the operation of the above configuration will be described. A ground fault occurs in the field circuit of the generator 1 and the field winding 2
When a field ground current flows through the rotor, the rotor temperature rises.
However, this rotor temperature data is supplied from the detector 22 to the arithmetic unit 36.
To correct the field ground resistance by performing the heat radiation calculation of the rotor temperature, and output this field ground fault correction data to the field ground relay 35.

As a result, in the field grounding relay 35,
As shown by the white arrow, the trip element setting value 8 is changed from “before correction” to “after correction” to increase the detection sensitivity setting. Therefore, the field grounding relay 35 is connected to the generator 1
The ground fault current Ig flowing through the field winding 2 is “after correction”.
When the set value exceeds the set value, it is determined that an abnormality has occurred, and the generator 1 whose rotor temperature has risen due to the occurrence of a field ground fault is safely protected by shutting off the circuit breaker or reducing the load. .

The arithmetic unit 36 corrects the field ground resistance as the detected rotor temperature approaches a steady value after a certain period of time has passed after the ground fault current Ig has flowed. An instruction is issued to return the set value of the relay 35 to the original value. Thus, the generator 1 can be appropriately and reliably protected not only when the field ground fault continues but also when the field ground fault occurs.

The eighth embodiment relates to a protection device according to claim 8, which is a modification of the seventh embodiment, and has the same structure, operation and function as the seventh embodiment. The description of the effect is omitted. As shown in the circuit configuration diagram of FIG. 8, in the generator 1, the generated power is supplied to an external system.

As protection of a field ground fault in the generator 1, the protection relay is operated by a field ground current, and its trip characteristic is set to a trip element setting value 8 with respect to a ground fault current Ig and an operation time t. A certain field grounding relay 35 is provided. Further, a field current detector 18 provided in a field circuit of the field winding 2 and a field current and a field voltage from the field current detector 18 are taken out to obtain a field resistance R (R = V / I)
And a detector 22 for detecting the rotor temperature of the generator 1 from.

Further, from the rotor temperature data from the detector 22, the history of the rotor temperature is stored, and the field ground resistance due to the deterioration of the insulator is corrected. And a calculation unit 37 that outputs the signal to the field grounding relay 35.

Next, the operation of the above configuration will be described. A ground fault occurs in the field circuit of the generator 1 and the field winding 2
When a field ground current flows through the rotor, the rotor temperature rises,
Accordingly, the dielectric strength is reduced due to the deterioration of the insulator.

However, since the rotor temperature is taken from the detector 22 into the calculating section 37 and the history thereof is used to correct the field ground resistance due to the deterioration of the insulator, the field ground relay 35 is used.
Is calculated according to the field ground resistance correction data from the arithmetic unit 37.
As shown by the white arrow, the trip element setting value 8 is changed from “before correction” to “after correction” to increase the detection sensitivity setting.

Accordingly, the field grounding relay 35 determines that the ground fault current Ig flowing through the field winding 2 of the generator 1 is abnormal when the grounding current Ig exceeds the set value changed to “after correction”. Thus, by shutting off the circuit breaker or reducing the load, etc., the generator 1 whose rotor temperature has risen due to the occurrence of a field ground fault can be safely protected.

[0091]

As described above, according to the present invention, the temperature rise and the history of each part in the generator and the transformer connected to the generator can be obtained by
The generator and transformer can be safely protected in response to various failure conditions by performing corrections due to thermal resistance or deterioration of insulators and correcting the operation settling of the protection relay from this correction data. The reliability of the generator and the transformer is improved.

[Brief description of the drawings]

FIG. 1 is a circuit configuration diagram of a protection relay device according to a first embodiment of the present invention.

FIG. 2 is a circuit configuration diagram of a protection relay device according to a second embodiment of the present invention.

FIG. 3 is a circuit configuration diagram of a protection relay device according to a third embodiment of the present invention.

FIG. 4 is a circuit configuration diagram of a protection relay device according to a fourth embodiment of the present invention.

FIG. 5 is a circuit configuration diagram of a protection relay device according to a fifth embodiment of the present invention.

FIG. 6 is a circuit configuration diagram of a protection relay device according to a sixth embodiment of the present invention.

FIG. 7 is a circuit configuration diagram of a protection relay device according to a seventh embodiment of the present invention.

FIG. 8 is a circuit configuration diagram of a protection relay device according to an eighth embodiment of the present invention.

FIG. 9 is a circuit configuration diagram of a conventional reverse-phase protection relay device.

FIG. 10 is a circuit configuration diagram of a conventional overexcitation protection relay device.

FIG. 11 is a circuit configuration diagram of a conventional overload protection relay device.

FIG. 12 is a circuit configuration diagram of a conventional field ground protection relay.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Generator, 1a ... Stator winding, 2 ... Field winding, 3 ... Generator main circuit, 4 ... Transformer, 4a ... Transformer winding, 5, 10,
15, 19, 22, 26, 27, 31, 32: detector, 6, 21: reverse-phase overcurrent relay, 7: generator reverse-phase withstand, 8: trip element setting value, 9: alarm element setting value, 11 , 25… Overexcitation relay, 12
… Generator V / F tolerance, 13… Transformer V / F tolerance, 14… In-house transformer, 16, 30… Overcurrent relay, 17… Overload tolerance, 18…
Field current detector, 20, 35… Field ground fault relay, 23, 24, 2
8,29,33,34,36,37 ... arithmetic unit, F ... frequency, I ... current, an In ... negative sequence current, Rg ... field ground fault resistance, t, t ₁ ...
Operating time, V: voltage, Vf: field voltage.

Continuing from the front page (72) Inventor Rikio Sato 1 Toshiba-cho, Fuchu-shi, Tokyo Inside the Toshiba Fuchu Plant Co., Ltd. Reference) 5G044 AA01 AA03 AA04 AD01 BA01 BA02 BA03 BA04 BA06 5G058 EE10 EF02 EG09

Claims (8)

[Claims] A negative-phase overcurrent relay that operates by a negative-phase current in a generator main circuit; and a negative-phase overcurrent relay in the negative-phase overcurrent relay based on correction data of a negative-phase tolerance of the generator by calculating heat dissipation of a rotor temperature of the generator. A protection relay device comprising: a calculation unit that changes an operation settling of a current-operation time characteristic. 2. A reverse-phase overcurrent relay operated by a reverse-phase current in a generator main circuit, and the reverse-phase tolerance correction data of the generator based on a history calculation of the reverse-phase current flowing through the generator main circuit. A protection relay device comprising: an operation unit for changing an operation setting of a reverse-phase current-operation time characteristic in an overcurrent relay. 3. An over-excitation relay that operates by over-excitation from the voltage and frequency of the main circuit of the generator, and a generator and a transformer that perform radiation calculation based on the temperature of the generator and the temperature of a transformer connected to the generator circuit. A protection unit comprising: an operation unit for changing an over-excitation voltage and an operation setting of a frequency-operation time characteristic in the over-excitation relay from over-excitation tolerance correction data of the device. 4. An over-excitation relay that operates by over-excitation from the voltage and frequency of the generator main circuit, and is connected to the generator and generator circuit based on a history calculation of the voltage and frequency applied to the generator main circuit. And a computing unit for changing an over-excitation voltage and an operation setting of a frequency-operation time characteristic of the over-excitation relay from the over-excitation tolerance correction data of the transformer. 5. An overcurrent relay which is activated by an overcurrent in the generator main circuit, the temperature of the stator windings of the generator and / or the temperature of the transformer windings and / or insulating oil connected to the generator circuit. The relay current in the overcurrent relay is calculated from the overload tolerance correction data by the heat radiation calculation based on the temperature.
A protection relay device comprising: an operation unit for changing an operation setting of an operation time characteristic. 6. An overcurrent relay operated by an overcurrent in a generator main circuit, and an overload of the generator and a transformer connected to the generator circuit based on a history calculation of the overcurrent flowing in the generator main circuit. A protection unit that changes an operation setting of a current-operation time characteristic in the overcurrent relay from the tolerance correction data. 7. A field grounding relay operated by a field grounding resistance in a field circuit of a generator, and a field grounding resistance correction data obtained by a radiation calculation of a rotor temperature obtained from the field circuit. A protection relay device comprising: a calculation unit that changes an operation setting of a field current-operation time characteristic in a magnetic grounding relay. 8. A field grounding relay operated by a field grounding resistance in a field circuit of a generator, and a field grounding resistance correction data obtained by calculating a rotor resistance of a rotor temperature history obtained from the field circuit. A protection unit comprising: a calculation unit that changes an operation setting of a field current-operation time characteristic in the field grounding relay.