JPH0865882A - Control method and apparatus of primary-side breaker for transformer - Google Patents

Abstract

PURPOSE: To prevent magnetic flux in a breaker from rising over a limit of saturation flux when the breaker is closed, by calculating a waveform of magnetic flux delaying by 90 degrees from a waveform of primary-side voltage and controlling the make and break in a way that the waveform of magnetic- flux is continuous before breaking and after making. CONSTITUTION: A waveform of a primary-side voltage in a transformer is detected by a wave-form detection unit VD2. A magnetic-flux waveform delaying by 90 degrees from the primary-side waveform is calculated by a core magnetic flux calculation unit CM2. At the same time, a beaker control unit CB2X controls make and break timing for a breaker so that a magnetic-flux waveform calculated by a core magnetic flux calculation unit CM1 becomes continuous before breaking and after making. Then, the magnetic flux (ϕ) has a symmetric waveform on positive and negative sides from a zero base.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power receiving and transforming system for a power system, and more particularly to a control method and a control device for a transformer primary side circuit breaker incorporated in this power receiving and transforming system.

[0002]

2. Description of the Related Art FIG. 12 is a diagram showing a general power receiving and transforming system. The three-phase power supplied from the power generation system including the generator G and the ratio differential relay 87G for the first electric machine and the circuit breaker CB6 connected in parallel to the generator G is the cable head H2,
It is supplied to the power receiving and transforming system via H1. The three-phase power supplied to the power receiving and transforming system is supplied to the demand side bus BUS via the transformers T1 and T2 connected in parallel via the power receiving breaker CB1.

In the power receiving and transforming system having such a configuration, the ground fault overcurrent relay 51G and the reverse power relay 67P are connected to the demand side of the cable head H2 via the power receiving current transformer CT1. And, these relays 51G, 67
When P is abnormal, a circuit breaker control circuit (not shown) is activated to cut off the power receiving circuit breaker CB1 to ensure the safety of each device on the demand side.

The ratio differential relay 87T is a transformer T1.
, T2 protection. Furthermore, on the power generation system side, the generator G is protected by a ratio differential relay 87G.

[0005]

However, as shown in FIG.
In the power receiving and transforming system shown in (1), there were still the following problems to be solved. That is, the generator G is operating and the breaker CB6 and the breaker CB1 are closed during the power reception period on the customer side and one of the transformers T2 is in operation (the breakers CB5 and CB4 are closed). Then, when the circuit breaker CB2 is turned on while trying to operate the other transformer T1,
Excitation inrush current flows to 1.

The cause of the excitation inrush current of this transformer will be described with reference to FIG. As shown in FIGS. 13A and 13B, the iron core magnetic flux φ of the transformer has an AC magnetic flux waveform with a 90 ° phase delay with respect to the applied voltage V on the primary side (power source side) of the transformer.

As shown in FIG. 13 (e), the iron core magnetic flux φ of the transformer T1 in a stable state after the power is turned on has a rated magnetic flux crest value φ _M at a rated voltage centered on the 0 base (line). It has a balanced magnetic flux waveform in the positive and negative directions and does not exceed the saturation magnetic flux limit φ _S of the iron core. The saturation magnetic flux limit φ _S is usually designed to be about 1.5 times the rated magnetic flux crest value φ _M.

However, as shown in FIG. 13D, when the circuit breaker CB2 on the primary side of the transformer T1 is turned on, the transformer T1 is turned on.
When the primary side voltage V is 0 volt, the transformer iron core magnetic flux φ at the time of closing starts from the position of the valley in the AC waveform, and as shown in FIG. The magnetic flux is DC-biased by 2φ _M on the property side.

Furthermore, if the residual magnetic flux φ _R exists in the iron core before the transformer T1 is started, a DC bias magnetic flux of (φ _R + 2φ _M ) finally appears in the iron core. This magnetic flux greatly exceeds the saturation magnetic flux limit φ _S of the iron core, and enters into the air-core inductance region at the exceeded portion, resulting in a large exciting inrush current as shown in FIG. 13 (c).

Next, the cause of generation of the residual magnetic flux φ _R of the iron core in the transformer T1 will be described with reference to FIG. That is,
When the applied voltage V of the transformer shown in FIG. 14 (a) is zero,
When the breaker CB2 is cut off, as shown in FIG. 14 (b),
The magnetic flux φ remains in the transformer core in a peak state. The remaining magnetic flux (residual magnetic flux φ _R ) continues as it is without attenuation until the transformer is excited by the next closing of the circuit breaker.

As described above, the residual magnetic flux φ _R of the transformer T1
Or the magnetic flux φ exceeding the saturation magnetic flux limit φ _{S of the} iron core is generated in the transformer iron core due to the voltage application timing of the transformer primary side, etc., an exciting inrush current of the transformer T1 is generated.

Since this exciting inrush current contains a large amount of direct current component, the direct current component of this exciting inrush current causes an unnecessary reaction of the relay described below, and the circuit breaker is erroneously cut off, which seriously hinders the power supply of the system. Was a factor of.

(A) The DC component of the exciting inrush current to the transformer T1 flows into the power receiving current transformer CT1, and an error current is generated on the CT secondary side due to the DC biasing phenomenon of the current transformer, resulting in a ground fault overcurrent relay 51G1. Responds to a malfunction and cuts off the power receiving breaker CB1 by mistake.

(B) The exciting inrush current of the transformer T1 flows into the power receiving current transformer CT1. As a result, the reverse power relay 67P erroneously detects this exciting inrush current as a reverse power state and responds unnecessarily, and cuts off the power receiving breaker CB1 by mistake.

(C) The exciting inrush current of the transformer T1 also flows into each of the current transformers CT4 and CT5 on the power generation system side, and an error current is generated on the secondary side of the CT due to the DC biasing phenomenon of the current transformer to generate power. The machine protection ratio differential relay 87G unnecessarily responds, erroneously cuts off the power supply breaker CB6, and stops the generator G.

(D) The DC component contained in the exciting inrush current of the transformer T1 causes a DC voltage drop in the power transmission line between the cable heads H1 and H2 on the power transmission side. Due to this DC component voltage, the transformer T2 regenerates an exciting inrush current even though it has already been excited. This exciting inrush current causes the protection ratio differential relay 87T of the transformer T2 to react unnecessarily, and finally the circuit breakers CB5 and CB4 are erroneously cut off.

As described above, the exciting inrush current generated in the transformer T1 has various adverse effects on the power system. The present invention has been made in view of such circumstances, it is possible to prevent the magnetic flux φ of the transformer from exceeding the saturation magnetic flux limit φ _S at the time of closing the circuit breaker, it is possible to suppress the occurrence of exciting inrush current, power An object of the present invention is to provide a control method and a control device for a transformer primary-side circuit breaker, which can prevent unnecessary reaction of various relays of a system and can improve reliability of the entire power receiving and transforming system.

[0018]

In order to solve the above problems, in the invention of claim 1, a circuit breaker in a power receiving and transforming system for supplying AC power from a power source side to a demand side via a circuit breaker and a transformer. In a control method of a transformer primary side circuit breaker for controlling closing and breaking of a transformer, a primary side voltage waveform of a transformer is detected, and a magnetic flux waveform of a transformer iron core whose phase is delayed by 90 ° from the detected primary side voltage waveform. Is calculated, and the breaking timing and closing timing for the circuit breaker are controlled so that the calculated magnetic flux waveform is continuous before and after the circuit breaker is closed again.

According to the second aspect of the invention, the control of the transformer primary side circuit breaker for controlling the closing / closing of the circuit breaker in the power receiving and transforming system for supplying AC power from the power source side to the demand side via the circuit breaker and the transformer. In the device, a transformer voltage waveform detection unit that detects the primary voltage waveform of the transformer, and a first magnetic flux waveform calculation unit that calculates the magnetic flux waveform of the iron core of the transformer from the detected primary voltage waveform of the transformer. , A residual magnetic flux detecting means for detecting the magnetic flux value during the breaking operation of the circuit breaker as a residual magnetic flux from the calculated magnetic flux waveform, a residual magnetic flux storage means for storing and retaining the detected residual magnetic flux, and a primary side voltage waveform of the circuit breaker A circuit breaker voltage waveform detection unit, a second magnetic flux waveform calculation unit that calculates a magnetic flux waveform of the transformer core from the detected primary side voltage waveform of the circuit breaker, and a magnetic flux value in the calculated magnetic flux waveform Residual And Bei the flux value comparing unit for outputting the charged timing signal for breaker at each time that matches the bundle.

Further, in the control device for a transformer primary side circuit breaker according to a third aspect of the present invention, a transformer voltage waveform detecting section for detecting the primary side voltage waveform of the transformer, and the detected primary side voltage of the transformer. A first magnetic flux phase calculating section for calculating the magnetic flux phase of the iron core of the transformer from the waveform; and a residual magnetic flux phase detecting means for detecting the magnetic flux phase value during the breaking operation of the circuit breaker as the residual magnetic flux phase from the calculated magnetic flux phase. , A residual magnetic flux phase storage means for storing and holding the detected residual magnetic flux phase, a circuit breaker voltage waveform detection unit for detecting the primary side voltage waveform of the circuit breaker, and a transformer based on the detected primary side voltage waveform of the circuit breaker. A second magnetic flux phase calculation unit that calculates the magnetic flux phase of the iron core and a magnetic flux phase comparison unit that outputs a closing timing signal to the circuit breaker at each time when the calculated phase value of the magnetic flux phase matches the residual magnetic flux phase. To have.

According to another aspect of the control device of the present invention, the circuit breaker voltage phase detector for detecting the phase of the primary side voltage waveform of the circuit breaker and the detected primary side voltage phase of the circuit breaker are 9
And a voltage phase comparator that outputs a breaking timing signal to the breaker at each time corresponding to 0 ° or 270 °.

Further, in the control device of the fifth aspect, in addition to the control device of the invention of the fourth aspect, a circuit breaker voltage phase detection unit for detecting the phase of the primary side voltage waveform of the circuit breaker, and this detected. Primary side voltage phase of circuit breaker is 90 ° or 270 °
And a voltage phase comparison unit that outputs a closing timing signal to the circuit breaker at each time corresponding to.

According to a sixth aspect of the present invention, in addition to the control device of the second, third and fifth aspects, a manual start switch and an automatic start switch for the transformer, and a change time of the closed state of the breaker from the operation time of the manual start switch. The required closing time storage unit that detects and stores the closing required time up to, and the closing command to the circuit breaker at the time before the closing required time from the output time of the closing timing signal output after the operation time of the automatic start switch. An optimum closing command generator for outputting is added.

Further, the invention of claim 7 is the control device according to claim 4, wherein a manual stop switch and an automatic stop switch for the transformer and a time from the operation time of the manual stop switch to the open state change time of the circuit breaker. A shutdown time storage unit that detects and stores the shutdown time, and outputs a shutdown command to the circuit breaker at a time before the shutdown time output time of the shutdown timing signal output after the operation time of the automatic stop switch. An optimal shutoff command generator is added.

[0025]

First, the operation principle of the control method and the control device for the transformer primary side circuit breaker configured as described above will be described. The AC power supplied from the power supply side flows to the demand side through the breaker and the transformer. Since the transformer has an iron core, if the circuit breaker is turned on with the residual magnetic flux φ _{R of the} iron core being zero, the voltage waveform on the primary side (power supply side) of the circuit breaker will be the primary side (power supply side) of the transformer. The magnetic flux waveform of the magnetic flux φ of the iron core of the transformer has a phase delayed by 90 ° with respect to the voltage waveform of the primary side voltage V of the circuit breaker.

The cause of the magnetizing inrush current in the above-mentioned transformer is that the magnetic flux φ of the transformer exceeds the saturation magnetic flux limit φ _S , so that the magnetic flux φ is a positive / negative symmetrical waveform centered on the 0 base (0 line). You just need to maintain. That is, when the primary side voltage of the transformer is interrupted by the circuit breaker, the magnetic flux value at the time of interruption in the magnetic flux φ waveform with a 90 ° phase delay from the AC voltage applied at the time of interruption remains as the residual magnetic flux φ _R , but If the circuit breaker is turned on at the timing on the voltage waveform where the magnetic flux waveform before interruption is continuous, the magnetic flux φ maintains the positive / negative symmetrical waveform centered on the 0 base (0 line) and the magnetic flux φ changes The saturation magnetic flux limit φ _S is never exceeded.

Each of the inventions of claims 2 to 7 shows a specific control device to which the above-mentioned control method is applied. In the second aspect, the primary side voltage waveform of the transformer is detected and the magnetic flux waveform of the iron core of the transformer is calculated. Then, the residual magnetic flux at the time of interruption of the circuit breaker is stored and retained, and the circuit breaker is reclosed at the timing when the magnetic flux value of the magnetic flux waveform calculated from the primary leather side voltage waveform of the circuit breaker matches the stored residual magnetic flux. It

Therefore, the magnetic flux waveform is continuous before interruption and after reclosing, and the magnetic flux does not exceed the saturation magnetic flux limit φ _S. In the invention of claim 3, instead of the voltage value and the magnetic flux value in the voltage waveform and the magnetic flux waveform in claim 2, the residual magnetic flux phase is detected by using the voltage phase value and the magnetic flux phase value in the voltage waveform and the magnetic flux waveform. The circuit breaker is closed based on the voltage phase corresponding to the residual magnetic flux phase shifted by 90 °. Therefore, substantially the same effect as the invention of claim 2 is obtained.

In the invention of claim 4, the circuit breaker is broken at the timing when the primary side voltage phase of the circuit breaker is 90 ° or 270 °. As a result, the residual magnetic flux φ is cut off at 180 ° or 0 ° in the magnetic flux φ phase of the transformer.
_R becomes 0, and even if the circuit breaker is reclosed at any phase timing, the magnetic flux does not exceed the saturation magnetic flux limit φ _S.

According to the invention of claim 5, in addition to the breaking timing condition for the breaker in claim 4, the breaker is closed at the timing when the primary side voltage phase of the breaker is 90 ° or 270 °. As a result, the magnetic flux φ of the transformer is turned on at 180 ° or 0 ° in the phase φ, so that the magnetic flux φ of the transformer starts from 0 pace. Therefore, the magnetic flux does not exceed the saturation magnetic flux limit φ _S more reliably.

According to the sixth aspect of the invention, a manual starting switch and an automatic starting switch for the transformer are provided. Then, in advance, the manual start switch is operated to store and hold the closing required time from the operation time to the circuit breaker closed state change time.

Therefore, thereafter, if the automatic start switch is operated, the closing command is automatically output at the optimum timing for the circuit breaker at a time before the closing required time before the output time of the closing timing signal described above.

According to the invention of claim 7, a manual stop switch and an automatic stop switch for the transformer are provided. Then, in advance, the manual stop switch is operated to store and hold the breaking required time from the operation time to the breaker open state change time.

Therefore, if the automatic shutoff switch is operated thereafter, the shutoff command is automatically output at the optimum timing for the circuit breaker at a time before the shutoff required time from the output time of the shutoff timing signal described above.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing a main part of a power receiving and transforming system in which a control device to which a control method for a primary side circuit breaker of the embodiment is applied is incorporated. The same parts as those in the conventional power receiving and transforming system shown in FIG. 12 are designated by the same reference numerals. Therefore, detailed description of the overlapping portions is omitted.

In the power receiving and transforming system in which the device of this embodiment is incorporated, the voltage on the primary side (power supply side) of the circuit breaker CB2 to be controlled is input to the circuit breaker control device CB2X via the voltage transformer TT1. . Similarly, the primary side (power source side) voltage of the transformer T1 is input to the circuit breaker control device CB2X via the instrument transformer TT2. Also, the circuit breaker CB2
Is controlled by the circuit breaker drive device CB2Y.

Each operation signal from the manual starting switch 3HM, the manual stopping switch 3KM, the automatic starting switch 3HA, and the automatic stopping switch 3KA for the transformer T1 is input to the circuit breaker controller CB2X.

Further, the circuit breaker control device CB2X sends a closing command and a breaking command to the circuit breaker drive device CB2Y via the closing auxiliary relay CLX and the opening auxiliary relay OPX to control the opening / closing of the circuit breaker CB2. Further, the circuit breaker control device CB2X reads the actual open / closed state of the circuit breaker CB2 via the interlocking contact CB2Z.

(First Embodiment) FIG. 2 is a block diagram showing the schematic arrangement of a circuit breaker control device CB2X according to the first embodiment.

From the transformer primary side voltage detected by the instrument transformer PT2 shown in FIG. 1, the transformer voltage waveform detector VD2 is detected.
At the transformer primary side voltage waveform is detected. The detected primary voltage waveform of the transformer is differentiated by the voltage differentiator DEL. Further, the same primary side voltage waveform is converted into a magnetic flux value by the magnetic flux value calculation unit CM2. Further, the same primary side voltage waveform is sent to the timing detector TA2.

The timing detecting section TA2 as the residual magnetic flux detecting means detects the loss timing of the primary side voltage of the transformer T1 from the value of the voltage differentiating section DEL and the value of the voltage waveform detecting section VD2. When the loss timing is output by the timing detection unit TA2, the residual magnetic flux value memory RM2 stores the magnetic flux value of the magnetic flux value calculation unit CM2 as the residual magnetic flux φ _R.

The voltage waveform detector VD1 detects the voltage waveform of the circuit breaker primary side from the voltage of the primary side of the circuit breaker CB2 detected by the voltage transformer PT1 shown in FIG. The detected primary side voltage waveform of the circuit breaker is converted into the magnetic flux value φ every moment by the magnetic flux value calculation unit CM1. The magnetic flux value comparison unit CLTP outputs the closing timing pulse signal TT1 at the timing when the momentary magnetic flux value from the magnetic flux value calculation unit CM1 and the residual magnetic flux φ _R coincide with each other.

The circuit breaker control device CB2 configured as described above
The operation of X will be described with reference to the time charts of FIGS. Instrument transformer P on the transformer side of the circuit breaker CB2
At T2, the transformer primary voltage value is detected and transmitted to the circuit breaker controller CB2X. This voltage waveform is shown in Figure 3.
The waveform is as shown in (a). The waveform of FIG. 3B is shown in FIG.
It is a differential waveform of the voltage waveform of (a). In addition, FIG.
Is the waveform of the magnetic flux φ of the iron core of the transformer T1.

The magnetic flux waveform of the transformer core is 90 ° with respect to the applied voltage while the sine wave voltage V is applied to the transformer core.
It becomes a delayed sine waveform. When the applied voltage to the iron core is lost, the magnetic flux value immediately before that is left as the residual magnetic flux φ _R.

Since it is difficult and almost impossible to measure the magnetic flux value of the transformer core magnetic flux φ, the transformer core magnetic flux waveform shown in FIG. 3D is calculated from the relationship between the core magnetic flux and the applied voltage. .

The loss timing T1 of the transformer primary voltage is
It is detected by a logical product (AND) condition that the primary voltage waveform of the transformer in FIG. 3A becomes 0 base and that the absolute value of the primary voltage change rate of the transformer in FIG. 3B is large.

FIG. 3C immediately before the loss timing T1
Magnetic flux value of transformer core (90 for transformer core applied voltage
° Delayed phase) is calculated. This calculated magnetic flux value becomes the residual magnetic flux φ _R of the transformer core. Then, the residual magnetic flux φ _R of the transformer core is stored, and the circuit breaker CB2 waits for a closing command.

FIG. 3 (d) shows the voltage waveform of the transformer PT1 for measuring instruments, and FIG. 3 (e) shows the voltage waveform of FIG. 3 (d).
° The calculated magnetic flux waveform of the transformer core with phase delay.
In the calculated assumed magnetic flux waveform of the transformer core, as shown in FIG. 4 (a), the closing timing T2 of the circuit breaker CB2 is adjusted so that the applied magnetic flux φ _D immediately after the closing matches the residual magnetic flux φ _R. do it.

Specifically, when the closing command is input at the timing of FIG. 4 (c), the above-mentioned closing timing T
By closing at 2, the circuit breaker CB2 changes from the off state (open state) to the on state (closed state) at the timing shown in FIG. 4 (d).

As a result, when the residual magnetic flux φ _R and the applied magnetic flux φ _D at the time of closing match, the magnetic flux waveform of the transformer iron core after closing is 0 DC without bias as shown in FIG. 4 (a). The waveform becomes symmetrical with respect to the base, the magnetic flux value does not exceed the saturation magnetic flux limit φ _S of the transformer core, and it is possible to prevent the occurrence of exciting inrush current.

(Second Embodiment) FIG. 5 is a block diagram showing a schematic configuration of a circuit breaker controller CB2X according to a second embodiment. The same parts as those of the circuit breaker controller CB2X of the first embodiment shown in FIG. 2 are designated by the same reference numerals. Therefore, detailed description of the overlapping portions is omitted.

From the transformer primary side voltage detected by the instrument transformer PT2 shown in FIG. 1, the transformer voltage waveform detector VD2 is detected.
At the transformer primary side voltage waveform is detected. The detected voltage waveform on the primary side of the transformer is phase-detected in time division by the voltage phase detector PHV2.

The timing detecting unit ZE2 as the residual magnetic flux phase detecting means receives the voltage zero of the voltage waveform detecting unit VD2 and the signal of the voltage phase detecting unit PHV2 and sends a voltage loss timing signal to the residual magnetic flux phase memory RMM2.

The magnetic flux phase calculator PHM2 calculates the phase (x + 90 °) of the magnetic flux φ of the iron core of the transformer T1 from the voltage phase x from the voltage phase detector PHV2, and sends the magnetic flux phase every moment. The residual magnetic flux phase memory RMM2 receives the voltage loss timing signal and receives the magnetic flux phase (x + 90) immediately before it.
) Is stored as a residual magnetic flux phase.

Further, the voltage waveform detector VD1 detects the voltage waveform of the circuit breaker primary side from the voltage of the primary side of the circuit breaker CB2 detected by the transformer PT1 for instrument shown in FIG. The detected primary side voltage waveform of the circuit breaker is converted into the magnetic flux phase x every moment by the magnetic flux phase calculator PHM1. Magnetic flux phase calculator P
The magnetic flux phase comparison unit CLMP outputs the closing timing pulse signal TT1 at the timing when the momentary magnetic flux phase from HM1 and the residual magnetic flux phase coincide with each other.

The circuit breaker control device CB2 configured as described above
The operation of X will be described with reference to the time chart of FIG. At the transformer PT2 for the instrument located on the transformer side of the circuit breaker CB2, the primary voltage value of the transformer is detected and the circuit breaker control device C
Sent to B2X. This voltage waveform becomes the waveform shown in FIG. One cycle in this voltage waveform is finely time-divided to sample the instantaneous voltage. It is detected that 0-based sampling of the instantaneous voltage continues several times, and the sampling timing immediately before that is the immediately preceding voltage value timing.

Further, in the above instantaneous voltage sampling, the voltage is changed every moment at the above-mentioned time division timing based on the zero cross timing such as the timing when the voltage changes from the positive polarity to the negative polarity and the timing when the negative polarity changes to the positive polarity. Sample the phase value. Then, the voltage phase value x ° at the voltage timing immediately before the voltage loss is read. The phase value delayed by 90 ° from the read voltage phase value x ° becomes the residual magnetic flux phase value (x + 90) ° of the transformer core. FIG. 6B shows the magnetic flux waveform of the transformer core when the primary voltage of the transformer is lost. This residual magnetic flux phase value (x + 90) ° is the residual magnetic flux phase memory RM.
It is stored and held in M2.

When the circuit breaker CB2 is turned on to activate the transformer T1, if the timing of applying the magnetic flux to the iron core is set to the same phase value as the residual magnetic flux phase value (x + 90) °, the residual magnetic flux φ _R Since the total waveform of the applied magnetic flux is a magnetic flux that is symmetric with respect to the 0 base and has no DC bias, the magnetic flux value does not exceed the saturation magnetic flux limit φ _S described above.

Therefore, the voltage phase x is detected from the detected voltage waveform of the instrument transformer PT1, and this voltage phase x leads the residual magnetic flux phase (x + 90) ° by 90 °.
°), the circuit breaker CB2 is turned on so that the saturation magnetic flux limit φ without DC bias in the iron core of the transformer T1.
The iron core magnetic flux waveform after injection that does not exceed _S can be obtained.

Therefore, it is possible to obtain substantially the same effect as that of the first embodiment shown in FIG. (Third Embodiment) FIG. 7 is a block diagram showing the schematic arrangement of a circuit breaker controller CB2X according to the third embodiment.

The primary side (power source side) voltage of the circuit breaker CB2 detected by the transformer PT1 for the instrument shown in FIG. 1 is detected by the circuit breaker voltage waveform detection section VD1. The detected primary side voltage waveform of the circuit breaker is input to the crest value timing generation section VMD as the next voltage phase comparison section.

The crest value timing generation unit VMD is a timing when the absolute value of the crest value of the circuit breaker primary side voltage waveform output from the circuit breaker voltage waveform detection unit VD1 reaches the maximum value V _M , that is, the circuit breaker primary side. The closing timing pulse signal TT1 and the breaking timing pulse signal TT2 are sent to the circuit breaker CB2 at the timing when the phases of the voltage waveforms coincide with 90 ° and 270 °.

The circuit breaker control device CB2 configured as described above
The operation of X will be described with reference to the time chart of FIG. Voltage transformer PT on the primary side (power supply side) of the circuit breaker CB2
At 1, the circuit breaker primary voltage value is detected and transmitted to the circuit breaker controller CB2X. Then, it is developed into the voltage waveform shown in FIG. Then, the peak value timing generation unit VMD outputs the peak value timing (90
, 270 °), the cut-off timing pulse signal TT2 is output so that the breaker CB2 is cut off.

Crest value timing of voltage waveform (90 °, 2
When the voltage loss occurs at 70 °), the loss timing is as shown in FIG. 8 (b), the iron core magnetic flux φ of the transformer T1.
At 0 °, 180 °, 360 °
It becomes the timing of °. At this timing, since the iron core magnetic flux waveform is at the 0 cross point, the residual magnetic flux φ _R of the iron core of the transformer T1 becomes zero.

Therefore, the residual magnetic flux φ _R of the transformer core after the loss of the primary voltage of the transformer T1 becomes zero, so that the magnetic flux waveform when the voltage is applied again to the primary side of the transformer T1 is the applied magnetic flux φ Since the residual flux φ _R is not added, the flux φ never exceeds the saturation flux limit φ _s .

That is, no matter what phase timing the circuit breaker CB2 is reclosed, the magnetic flux φ
Does not exceed the saturation magnetic flux limit φ _S. Furthermore, when the circuit breaker CB2 is closed according to the closing timing pulse signal TT1 in addition to the above-described cutoff timing control, the residual magnetic flux φ _R of the transformer T1 is zero, and the iron core applied magnetic flux of the transformer T1 is 90%. ° Magnetic flux φ of transformer T1 due to delay
Starts from 0 base as shown in FIG. 8 (b).

When starting from 0 base, the applied magnetic flux waveform has a peak value up to the normal magnetic flux peak value φ _M , and becomes a sine wave with no DC bias, which does not exceed the saturation magnetic flux limit φ _s and the exciting inrush current. Is more reliably prevented from occurring.

8 (c) and 8 (d) show that the circuit breaker CB2 actually shifts to the closed state TC1 hour after the input of the start command to the transformer T1. Further, FIGS. 8 (e) and 8 (d) show that the breaker CB2 actually shifts to the open state two hours after the input of the stop command to the transformer T1.

(Fourth Embodiment) FIG. 9 is a block diagram showing the schematic arrangement of a circuit breaker controller CB2X according to the fourth embodiment.

To the circuit breaker control device CB2X of this embodiment, operation commands from the manual starting switch 3HM, the manual stopping switch 3KM, the automatic starting switch 3HA, and the automatic stopping switch 3KA for the transformer T1 are input. The fact that each switch 3HM, 3KM, 3HA, 3KA has been operated means that in the circuit breaker control device CB2X,
It is selected by each of the manual operation detecting units 3HMX, 3KMX and each of the automatic operation detecting units 3HAX, 3KAX.

The circuit breaker state detection unit CB2Z constantly monitors the open / closed state of the circuit breaker CB2 to be controlled. The closing time storage unit HRE2 closes the circuit breaker CB2 detected by the circuit breaker state detection unit CB2Z from the open state from the operation detection time of the manual start switch 3HM shown in FIG. 10 (a) from the manual operation detection unit 3HMX. The required injection time T2 shown in FIG. 10 (b) until the time when the state is changed to the established state is detected and stored.

In this case, the manual starting switch 3HM
The timing at which the closing timing pulse signal for the circuit breaker CB2 is actually sent to the circuit breaker drive device CB2Y after is operated is equal to the timing in the first and second embodiment devices described above. That is, the magnetic flux φ of the transformer T1 is turned on under the condition that the saturation magnetic flux limit φ _S is not exceeded.
The closing required time T2 stored in the closing required time storage unit HRE2 is sent to the optimum closing instruction generating unit TTHY.

Similarly, the interruption required time storage unit KRE2 is
From the operation detection time of the manual stop switch 3KM shown in FIG. 11 (a) from the manual operation detection unit 3KMX to the time when the circuit breaker CB2 detected by the circuit breaker state detection unit CB2Z changes from the closed state to the open state. The interruption required time T5 shown in FIG. 11 (b) is detected and stored.

In this case, the manual stop switch 3KM
Is operated, the timing at which the interruption timing pulse signal for the circuit breaker CB2 is actually sent to the circuit breaker drive device CB2Y is equal to the timing in the third embodiment device described above. That is, the magnetic flux φ of the transformer T1 is turned on under the condition that the saturation magnetic flux limit φ _S is not exceeded.

The shutoff required time T5 stored in the shutoff required time storage unit KRE2 is sent to the optimum shutoff command generation unit TTKY. Before operating the automatic start switch 3HA and the automatic stop switch 3KA, the operator operates the manual start switch 3HM and the manual stop switch 3KM to store the closing time T2 and the closing time T5 described above in advance. HRE2 and shutoff time storage KRE
Keep it in memory 2.

With the above preparation process completed,
The operation of each unit when the operator operates the automatic start switch 3HA will be described with reference to the time charts of FIGS.

The time charts of FIGS. 10 (a) and 10 (b) and the time charts of FIGS. 10 (c) to 10 (h) are not on the same time axis, but the time charts of FIGS. 10 (c) to 10 (h). The time axis of is a time considerably later than the time charts of FIGS. 10A and 10B.

Optimal closing timing pulse gate TTHY
When an automatic start operation command due to the automatic start switch 3HA shown in FIG. 10 (c) is input, as shown in FIG. 10 (e), the gate is opened for a predetermined closing idling time T3 and input. The above mentioned closing timing pulse signal TT1 is sent to the optimum closing command generating section TTHY.

The optimum closing command generator TTHY is shown in FIG.
As shown in (e), at the time (timing) prior to the required closing time T2 from the input timing of the last closing timing pulse signal TT1 of the plurality of closing timing pulse signals TT1 input within the closing idling time T3. , And sends the closing command shown in FIG. 10 (f) to the next automatic closing command unit TTHZ.

Incidentally, FIG. 10 (d) shows the voltage waveform on the primary side of the circuit breaker CB2. The automatic closing command section TTHZ converts the input closing command into a driving signal shown in FIG. 10 (g) having a sufficient pulse length necessary for driving the circuit breaker CB2,
It is sent to the closing auxiliary relay CLX and the circuit breaker driving device CB2Y of FIG. 1 through the driving transistor TR.

As shown in FIG. 10 (h), the actual circuit breaker CB2 has the above-mentioned required time T2 from the output time of the drive signal.
At the elapsed time, the open state is changed to the closed state. Next, the operation of each unit when the operator operates the automatic stop switch 3KA will be described with reference to the time charts of FIGS.

The time charts of FIGS. 11 (a) and 11 (b) and the time charts of FIGS. 11 (c) to 11 (h) are not on the same time axis, but the time charts of FIGS. 11 (c) to 11 (h). The time axis of is a time considerably later than the time charts of FIGS. 11 (a) and 11 (b).

Optimal cutoff timing pulse gate TTKY
When the automatic stop operation command due to the automatic stop switch 3KA shown in FIG. 11 (c) is input, as shown in FIG. 11 (e), the gate is opened for a predetermined shutoff idling time T6 and the input is made. The cut-off timing pulse signal TT2 described above is sent to the optimum cut-off command generator TTKY.

The optimum shutoff command generator TTKY is shown in FIG.
As shown in (e), at the time (timing) before the interruption required time T5 from the input timing of the last interruption timing pulse signal TT2 of the plurality of interruption timing pulse signals TT2 input within the interruption idling time T6. , And sends the closing command shown in FIG. 11 (f) to the next automatic shutoff command unit TTKZ.

FIG. 11D shows the voltage waveform on the primary side of the circuit breaker CB2. The automatic shutoff command unit TTKZ converts the input shutoff command into a drive signal shown in FIG. 11 (g) having a sufficient pulse length necessary to drive the circuit breaker CB2,
It is sent to the auxiliary auxiliary relay OPX and the circuit breaker drive device CB2Y of FIG. 1 through the drive transistor TR.

As shown in FIG. 11 (h), the actual circuit breaker CB2 has the breaking time T5 from the output time of the drive signal.
When the time has passed, the closed state is changed to the open state. In this way, when the closing required time T2 is measured in advance and the automatic start switch 3HA is operated, the closing command is transmitted at a timing before the closing required time T2 is subtracted, so that the delay time on the circuit is delayed. The circuit breaker CB2 can be turned on with more accurate timing including the above.

Similarly, when the cutoff required time T5 is measured in advance and the automatic stop switch 3KA is operated, the cutoff command is sent at a timing before the cutoff required time T5 is subtracted. It is possible to break the circuit breaker CB2 at a more accurate timing including the time.

In the apparatus of the embodiment, the transformer T1
The residual magnetic flux or residual magnetic flux phase of the iron core of the transformer T1 is calculated at the timing when the primary side voltage of the transformer T1 is lost. Therefore, this method can also be applied to residual magnetic flux such as power interruption in the upper power system on the power supply side or protection interruption due to relay operation, and more reliable generation of magnetic inrush current when closing the circuit breaker on the primary side of the transformer. Can be prevented.

Further, since the magnetizing inrush current does not occur in the transformer T1, in addition to the above-mentioned characteristics and reliability advantages, the magnetizing inrush current malfunction prevention circuit in the conventional relay circuit or the like can be deleted. There is an effect that it is not necessary to look at the excitation inrush current time for protection cooperation. further,
The main circuit itself including the transformer body can prevent the generation of unnecessary large current (exciting inrush current), so that the life of each component can be extended.

[0090]

As described above, in the control method of the transformer primary side circuit breaker in the power receiving and transforming system of the present invention, the primary side voltage waveform of the transformer is detected, and the detected primary side voltage waveform is detected. Calculate the magnetic flux waveform of the iron core of the transformer with a 90 ° phase delay, and control the breaking timing and closing timing for the circuit breaker so that the calculated magnetic flux waveform continues before and after closing the circuit breaker. ing.

Therefore, when the circuit breaker is turned on again, if the circuit breaker is turned on at the timing on the voltage waveform where the magnetic flux waveform before interruption remains as it is, the magnetic flux φ is 0 base (0 line).
Maintaining the positive and negative target waveform around the saturation magnetic flux limit phi _S
Never exceeds.

Therefore, it is possible to prevent the magnetic flux of the transformer from exceeding the saturation magnetic flux limit φ _S when the breaker is turned on, it is possible to suppress the generation of the inrush current of the excitation, and it is possible to prevent unnecessary reaction of various relays of the power system, and The reliability of the entire power receiving and transforming system can be improved.

Further, in the control device for a transformer primary circuit breaker of the present invention, the residual magnetic flux value or residual magnetic flux phase of the exciting magnetic flux of the transformer at the time of interruption is stored in memory, and the stored residual magnetic flux value or residual magnetic flux value The closing timing for the circuit breaker is controlled based on the magnetic flux phase. Therefore, like the above-described invention, it is possible to prevent the magnetic flux φ of the transformer from exceeding the saturation magnetic flux limit φ _S when the breaker is closed.

In a control device for a transformer primary circuit breaker of still another invention, the circuit breaker has a circuit breaker timing of 90.
It is set to ° or 270 °. Therefore, the phase of the magnetic flux at the time of interruption can be forcibly controlled to 180 ° or 0 °, and with a simple configuration, it is possible to prevent the magnetic flux of the transformer from exceeding the saturation magnetic flux limit φ _S when the circuit breaker is closed.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a power receiving and transforming system incorporating a control device for a transformer primary side circuit breaker according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a schematic configuration of a circuit breaker control device according to a first embodiment incorporated in the power receiving and transforming system.

FIG. 3 is a time chart showing the operation of the apparatus of the embodiment.

FIG. 4 is a time chart showing the operation of the apparatus of the same embodiment.

FIG. 5 is a block diagram showing a schematic configuration of a circuit breaker control device according to a second embodiment of the present invention.

FIG. 6 is a time chart showing the operation of the apparatus of the embodiment.

FIG. 7 is a block diagram showing a schematic configuration of a circuit breaker control device according to a third embodiment of the present invention.

FIG. 8 is a time chart showing the operation of the apparatus of the embodiment.

FIG. 9 is a block diagram showing a schematic configuration of a circuit breaker control device according to a fourth embodiment of the present invention.

FIG. 10 is a time chart showing the operation of the apparatus of the embodiment.

FIG. 11 is a time chart showing the operation of the apparatus of the same embodiment.

FIG. 12 is a schematic configuration diagram of a conventional power receiving and transforming system.

FIG. 13 is a time chart for explaining a problem of closing timing of the circuit breaker in the conventional system.

FIG. 14 is a time chart for explaining the problem of the closing timing of the circuit breaker in the same conventional system.

[Explanation of symbols]

PTT1, PTT2 ... Instrument transformer, T1 ... Transformer, C
B2 ... Circuit breaker, CB2X ... Circuit breaker control device, CB2Y ...
Circuit breaker drive device, 3HM ... Manual start switch, 3KM ...
Manual stop switch, 3HA ... Automatic start switch, 3KA
... automatic stop switch, VD1, VD2 ... voltage waveform detection section, CM1, CM2 ... magnetic flux calculation section, RM1 ... residual magnetic flux memory, RMH2 ... residual magnetic flux phase memory, CLTP ... magnetic flux value comparison section, CLMP ... magnetic flux phase comparison section, PHV1 , PH
V2 ... Voltage phase detector, PHM1, PHM2 ... Magnetic flux phase calculator

Claims (7)

[Claims] 1. A method for controlling a transformer primary-side circuit breaker for controlling closing and closing of the circuit breaker in a power receiving and transforming system that supplies alternating-current power from a power source side to a demand side through a circuit breaker and a transformer. Detecting the primary side voltage waveform of the transformer, calculating the magnetic flux waveform of the iron core of the transformer with a 90 ° phase delay from the detected primary side voltage waveform, and before and after reclosing the circuit breaker, A control method for a transformer primary-side circuit breaker, which controls the circuit breaker timing and closing timing so that the calculated magnetic flux waveform is continuous. 2. A transformer primary-side circuit breaker control device for controlling closing and closing of the circuit breaker in a power receiving and transforming system for supplying AC power from a power source side to a demand side via a circuit breaker and a transformer. A transformer voltage waveform detecting section for detecting a primary side voltage waveform of the transformer, and a first magnetic flux waveform calculating section for calculating a magnetic flux waveform of the iron core of the transformer from the detected primary side voltage waveform of the transformer, A residual magnetic flux detecting means for detecting a magnetic flux value during the breaking operation of the circuit breaker as a residual magnetic flux from the calculated magnetic flux waveform; a residual magnetic flux storage means for storing and holding the detected residual magnetic flux; and a primary side of the circuit breaker. A circuit breaker voltage waveform detection unit that detects a voltage waveform; a second magnetic flux waveform calculation unit that calculates a magnetic flux waveform of the iron core of the transformer from the detected primary side voltage waveform of the circuit breaker; The transformer primary circuit breaker of the control device that includes a magnetic flux value comparing unit flux value outputs poured timing signal for the breaker at each time that matches the residual magnetic flux in the waveform. 3. A transformer primary-side circuit breaker control device for controlling closing and closing of the circuit breaker in a power receiving and transforming system for supplying AC power from a power source side to a demand side through a circuit breaker and a transformer. A transformer voltage waveform detecting section for detecting a primary side voltage waveform of the transformer, and a first magnetic flux phase calculating section for calculating a magnetic flux phase of the iron core of the transformer from the detected primary side voltage waveform of the transformer, A residual magnetic flux phase detecting means for detecting a magnetic flux phase value during a breaking operation of the circuit breaker as a residual magnetic flux phase from the calculated magnetic flux phase; a residual magnetic flux phase storing means for storing and holding the detected residual magnetic flux phase; A circuit breaker voltage waveform detection unit that detects the primary side voltage waveform of the circuit breaker; and a second magnetic flux phase calculation unit that calculates the magnetic flux phase of the iron core of the transformer from the detected primary side voltage waveform of the circuit breaker. A controller for a transformer primary-side circuit breaker, comprising: a magnetic flux phase comparison unit that outputs a closing timing signal to the circuit breaker at each time when the calculated phase value in the magnetic flux phase matches the residual magnetic flux phase. 4. A transformer primary-side circuit breaker control device for controlling closing and closing of the circuit breaker in a power receiving and transforming system for supplying AC power from a power source side to a demand side through a circuit breaker and a transformer. Circuit breaker voltage phase detector for detecting the phase of the primary side voltage waveform of the circuit breaker, and the detected primary side voltage phase of the circuit breaker is 90 ° or 2
A controller for a transformer primary-side circuit breaker, comprising: a voltage phase comparison unit that outputs a circuit break timing signal to the circuit breaker at each time corresponding to 70 °. 5. A circuit breaker voltage phase detector for detecting the phase of the primary side voltage waveform of the circuit breaker, and the detected primary side voltage phase of the circuit breaker is 90 ° or 2
The control device for the transformer primary-side circuit breaker according to claim 4, further comprising a voltage phase comparator that outputs a closing timing signal to the circuit breaker at each time corresponding to 70 °. 6. A manual starting switch and an automatic starting switch for the transformer, and a closing required time storage unit for detecting and storing a closing required time from an operation time of the manual starting switch to a closing state change time of the circuit breaker. And an optimum closing command generation unit that outputs a closing command to the circuit breaker at a time before the closing required time from the output time of the closing timing signal output after the operation time of the automatic start switch. Item 6. A control device for a transformer primary side circuit breaker according to any one of items 2, 3 and 5. 7. A manual stop switch and an automatic stop switch for the transformer, and a required shutoff time storage unit for detecting and storing the required shutoff time from the operation time of the manual stop switch to the open state change time of the circuit breaker. And an optimal cutoff command generation unit that outputs a cutoff command to the circuit breaker at a time before the cutoff required time from the output time of the cutoff timing signal output after the operation time of the automatic stop switch. Item 4. A control device for a transformer primary side circuit breaker according to Item 4.