JP7412309B2 - Grid integration device - Google Patents

Description

The present disclosure relates to a grid joining device.

A synchronous phase modifier is a device that supplies reactive power to the grid by adjusting excitation current, and because it has inertia due to rotation, it is one of the measures to stabilize the grid in response to an increase in the renewable energy generation ratio of the grid.

As a method for starting a synchronous phase modifier from a stopped state, an "inverter starting method" is used in which a starting inverter is used to start the synchronous phase modifier as a synchronous motor.

In the "inverter starting method," the voltage of the synchronous phase modifier is different from the voltage of the starting inverter, so it is not possible to connect to the grid while driving the inverter. Therefore, before the synchronous phase modifier is connected to the system, the starting inverter is electrically disconnected from the synchronous phase modifier.

In conventional synchronous phase modifiers, the speed of the synchronous phase modifier is increased to the rated speed by the starting inverter, and then the synchronous phase modifier is disconnected from the starting inverter, allowing free rotation from a speed higher than the rated speed. An excitation current is passed from the excitation device, and the rotational speed of the synchronous phase modifier gradually decreases due to corresponding losses equivalent to the reaction torque such as bearing loss and windage loss.

After the rotation speed of the synchronous phase modifier starts to decrease, the parallel circuit breaker must be closed in a synchronized state in which the difference between the grid voltage and the terminal voltage of the synchronous phase modifier, the frequency difference, and the phase difference are within the specified values. . This is to avoid mechanical damage to the equipment. For example, even if the voltage difference is within ±1% and the frequency difference is within ±0.1Hz, if the voltage phase difference is outside ±15°, the parallel The circuit breaker is not closed, and it is necessary to connect and operate the starting inverter to the synchronous phase modifier again to accelerate the synchronous phase modifier again.

JP-A-4-165992 (pages 665-671, Figure 1)

The starting operation pattern of the conventional synchronous phase modifier shown in FIG. It operates to a rotation speed higher than a certain rated 1 pu, for example 1.05 pu, and shifts to a speed lower than the synchronous speed as free rotation.

After that, when the grid voltage and the voltage at the terminals of the synchronous phase modifier are synchronized, the parallel circuit breaker is closed using a synchronization tester. The synchronous phase modifier described in Patent Document 1 is driven by the method described above.

As mentioned above, the synchronous phase modifier passes through the synchronous speed with free rotation, so if any one of the voltage differences, frequency differences, and phase differences between the grid voltage and the terminals of the synchronous phase modifier exceeds the specified value. Parallel circuit breakers cannot be closed. Therefore, in order to reaccelerate the synchronous phase modifier, it was necessary to lower the excitation current, connect the starting inverter to the synchronous phase modifier and operate it again, and reaccelerate, resulting in a time loss.

Furthermore, if the winding temperature or the like exceeds the temperature limit due to multiple re-accelerations of the synchronous phase modifier, complicated operations such as providing a cooling period become necessary.
As a result, it is not possible to connect the synchronous phase modifier to the grid in a timely manner based on supply and demand commands from the grid, which in turn reduces the power quality of the grid, leading to problems such as voltage drops leading to power transmission outages for extra high-voltage customers. There was a point.

The present disclosure has been made to solve the above-mentioned problems, and the synchronous phase modifier rotates the rotor freely from a rotation speed higher than the rated rotation speed to close the parallel circuit breaker of the synchronous phase modifier. During this period, calculate the voltage difference using the instantaneous values of the parallel circuit breaker's system voltage and the voltage at the terminals of the synchronous phase modifier, and use this and the rotation speed and reaction torque data to calculate the voltage difference of the synchronous phase modifier. By adjusting and controlling the rotation speed and phase of the generator by increasing or decreasing the excitation current, it is possible to close the circuit breaker for parallel use of the synchronous phase modifier in a state where fluctuations in transient voltage and current to the power supply system are small, and The object of the present invention is to obtain a system joining device that can avoid failure of synchronous joining.

The system integration device disclosed in the present application is a system integration device that controls a synchronous phase modifier via an excitation device and a parallel circuit breaker, and uses the rotation speed, excitation current, etc. of the synchronous phase modifier as input information. , predicting a voltage envelope from a rotation speed higher than the synchronous speed of the synchronous phase modifier to system synchronization based on a rotation speed-rebellious torque curve of the synchronous phase modifier with the excitation current of the synchronous phase modifier as a parameter; The first calculation module is used to correct the rotational speed of the synchronous phase modifier by increasing or decreasing the voltage at the terminal of the synchronous phase modifier or by increasing or decreasing the excitation current. synchronous control and closing control of the parallel circuit breaker.

According to the system connection device disclosed in the present application, it is possible to close a circuit breaker for parallel use of a synchronous phase modifier in a state where fluctuations in transient voltage and transient current to the power supply system are small, and further, synchronous connection It has the effect of avoiding failure.

1 is a system configuration diagram including a grid joining device that controls a synchronous phase modifier according to Embodiment 1. FIG. It is a sequence diagram which shows the operation|movement as a comparative example of the system joining device which controls a synchronous phase modifier. It is a figure which shows the relationship between the reaction torque and rotation speed in a synchronous phase modifier. It is a figure showing the time transition of free rotation speed in a synchronous phase modulator. FIG. 3 is a diagram showing the relationship between repulsion loss and rotation speed in a synchronous phase modifier. FIG. 7 is a diagram showing the time transition of the rotational speed up to and including the synchronous speed in free rotation when the excitation current in the synchronous phase modifier is kept constant. It is a figure which shows the time transition of the rotation speed when the excitation current is used as a parameter in a certain rotation speed state in a synchronous phase modulator. It is a figure which shows an example of the example of calculation of (DELTA)V. It is a figure which shows an example of the example of calculation of (DELTA)V. It is a figure which shows an example of the example of calculation of (DELTA)V. FIG. 3 is a diagram showing a voltage difference envelope using frequency as a parameter. FIG. 3 is a diagram showing a voltage difference envelope and a combination sequence. FIG. 3 is a sequence diagram showing the operation of the system joining device according to the first embodiment. FIG. 7 is a diagram showing the operation of the system joining device according to the second embodiment. FIG. 7 is a diagram showing the operation of the system joining device according to Embodiment 3; FIG. 7 is a block diagram of a part of a system joining device according to a fourth embodiment. It is a figure which shows the detail at the time of system addition of a synchronous phase modifier.

Embodiment 1.
In the system connection device of the present disclosure, the synchronous phase modifier is electrically disconnected from the starting inverter, and the connection sequence is performed from a rotation speed higher than the rated rotation speed to free rotation operation and closing of the parallel circuit breaker. This is a device used in

Hereinafter, a grid joining device according to Embodiment 1 of the present disclosure will be described based on a system configuration diagram including the grid joining device that controls a synchronous phase modifier shown in FIG. 1.

In FIG. 1, a synchronous phase modifier 1 is connected to a power supply system 2 via a main transformer 3 and a parallel circuit breaker 4 (CB1). An excitation device 5 that controls the voltage of the synchronous phase modifier 1 excites the synchronous phase modifier 1 via a field breaker 6 . Power for this excitation device 5 is supplied from an excitation transformer 9 via a second excitation power supply circuit breaker 8 after the voltage of the synchronous phase modulator 1 is established. On the other hand, at the time of starting the synchronous phase modifier 1, since the voltage of the synchronous phase modifier 1 has not been established, the voltage of the synchronous phase modifier 1 is not established. Supplied from sources such as

The starting inverter 10 of the synchronous phase modifier 1 includes a converter section that converts alternating current (AC) to direct current (DC), and an inverter section that converts DC into variable speed frequency and voltage. The output side of the starting inverter 10 is connected to the synchronous phase modifier 1 via an output breaker 11. Further, the input side of the starting inverter 10 is connected to a station power source (not shown) or the like via a starting input transformer 12.

In the system connection device 20, the voltage of the power system 2 is detected via the second instrument transformer 15, and a voltage of 1 pu is outputted at the rated voltage, and the voltage at the terminal of the synchronous phase modifier 1 is detected through the first instrument transformer 15. A rated voltage of 1 pu is output through the transformer 14.
Here, the auxiliary contact 28 indicates the state of the parallel circuit breaker 4, and the closing coil 29 represents the closing coil of the parallel circuit breaker 4, respectively. The auxiliary contact 28 sends a signal to the system joining device 20 as an answerback of CB1. On the other hand, a signal is sent from the CB1 closing command terminal of the system joining device 20 to the CB1 closing coil 29.

Further, an automatic voltage regulator (AVR) 24 that controls the excitation device 5 has an AVR controller 25 and a comparator (not shown) for a reference signal (90R) and a voltage feed signal. For the operation of the joining device 20, the input of the synchronous phase modifier voltage correction signal (SC voltage correction signal: ΔIf) of the system joining device 20, and the signal switch 26 that enables the correction signal when starting the synchronous phase modifier 1. It has a correction signal adder/subtractor 27. The SC voltage is fed back to the adder/subtractor 27.

Next, the operation of the system joining device 20 that controls the synchronous phase modifier 1 according to the first embodiment will be described below.
In FIG. 1, when starting the synchronous phase modifier 1, the parallel circuit breaker 4, the first excitation power supply circuit breaker 7, the second excitation power supply circuit breaker 8, the field circuit breaker 6, and the output circuit breaker 11 of the starting inverter 10 are It is in an open state, and the synchronous phase modifier 1 is in a rotation stopped state or in an extremely low speed turning state.

Here, when a starting command for the synchronous phase modifier 1 is issued, the field breaker 6 is closed and the output breaker 11 is closed as a preparation stage for starting.

Next, the synchronous phase modifier 1 is excited by the excitation device 5 via the auxiliary power transformer 13 and the first excitation power supply circuit breaker 7, and the starting inverter 10 gradually rotates the synchronous phase modifier 1 as a synchronous motor. The synchronous phase modifier 1 is operated to a rotation speed higher than the synchronous speed. Note that the synchronous speed rating of the synchronous phase modifier 1 is 1 pu.

Regarding excitation, since the terminal voltage of the synchronous phase modifier is established when the rated value of 0.1 pu is exceeded, excitation power is then supplied via the excitation transformer 9 and the second excitation power supply circuit breaker 8. The excitation current output value signal from the excitation device 5 is sent to the excitation current If signal terminal of the system joining device 20 .

The operations of the first arithmetic module 20a and the second arithmetic module 20b, which are characteristic parts of the system joining device 20 according to the first embodiment, will be described later.
Note that, as shown in FIG. 1, the first arithmetic module 20a and the second arithmetic module 20b generally constitute a part of a central processing unit (CPU) 20c in the system joining device 20. However, it goes without saying that even if it is separately provided in a part other than the CPU 20c in the system joining device 20, the same function can be achieved.

FIG. 2(A) is a sequence diagram showing the operation of a system joining device as a comparative example, and FIG. 2(B) is an enlarged view of the vicinity of the joining point in FIG. 2(A). Here, the horizontal axis of the graph represents time, and the vertical axis represents the excitation current 21 of the synchronous phase modifier 1, the rotational speed 22 of the synchronous phase modifier 1, and the terminal voltage 23 of the synchronous phase modifier 1, respectively. In the enlarged view of FIG. 2(B), the lines of the excitation current 21, the rotational speed 22, and the terminal voltage 23 are drawn emphatically shifted in the vertical direction.

Since the starting inverter voltage has a lower rated voltage different from the rated voltage of the synchronous phase modifier 1, it is disconnected before paralleling to the grid. After that, the synchronous phase modifier 1 enters a state in which an exciting current is passed through it, and from a rotation speed higher than the rated rotation speed, it becomes free rotation and the voltage at the terminals of the synchronous phase modifier 1 changes from the voltage difference in the power supply system 2, the phase difference, and the frequency. When the difference is within the specified value, a closing signal is issued, the parallel circuit breaker 4 is closed, and the parallel connection is completed.

The synchronous phase modifier 1 is in a state of free rotation from a rotation speed higher than the rated rotation speed, and as the rotation speed decreases while reducing rotational energy due to losses due to bearings and wind damage, the voltage difference, frequency difference, and phase difference There were many cases where the synchronization was not within the specified value.
For this reason, in the system joining device according to the comparative example, a problem occurred in that if the voltages at the terminals of the synchronous phase modifier 1 could not be synchronized, re-acceleration was required.

The system connection device 20 according to the first embodiment performs synchronous control with the power system 2 by increasing or decreasing the excitation current of the synchronous phase modifier 1 in a free rotation state before the synchronous phase modifier 1 is connected to the power system 2. This is a device that performs highly accurate system merging.

The operation of the grid joining device 20 that controls the synchronous phase modifier 1 will be described below.
During free rotation of the synchronous phase modifier 1, the rotational energy E possessed by the rotor is expressed by the following equation (1). Note that the rotational angular velocity ω (rad/s) in equation (1) is expressed by equation (2).

(2) In the formula, I is the rotational moment of inertia of the rotor of the synchronous phase modifier 1 (kg m ² ), p is the number of poles of the synchronous phase modifier 1, N is the rotation speed at the relevant time (rpm), and f is the relevant Each represents the terminal voltage frequency (Hz) at the time.
Here, the unit of E is joule [J], and the moment of inertia GD2 has a relationship of GD2=4·I.

From equations (1) and (2), it can be seen that the rotational energy E that the synchronous phase modifier 1 has at a given rotation speed is uniquely determined by the rotational moment of inertia I.

The rotation speed of the synchronous phase modifier 1 is in a free rotation state, and due to the resistance loss shown in the relationship between resistance torque Tm and rotation speed shown in Fig. 3, such as rotor windage loss, bearing loss, etc. The rotational energy is lost and the rotational speed decreases. Note that FIG. 3 is a diagram showing the relationship between the excitation current (1 pu) of the synchronous phase modulator 1, the rotation speed, and the reaction torque with non-excitation (=0 pu) as parameters.

FIG. 4 is an example of how the rotational speed of the synchronous phase modifier 1 changes over time until it stops in free rotation. As time passes, the rotation speed of the synchronous phase modifier 1 decreases.

FIG. 5 is a diagram showing the relationship between the resistance loss P and the rotation speed of the synchronous phase modifier 1. As the rotational speed of the synchronous phase modifier 1 increases, the reaction torque increases, and when the excitation current of the synchronous phase modifier 1 is increased, the reaction torque also increases, and when the excitation current is reduced, the reaction torque also decreases. Note that FIG. 5 shows cases where the excitation current of the synchronous phase modulator 1 is 1 pu, 0.5 pu, and non-excitation, that is, 0 pu.

Here, the following equation (3) holds true between the reaction loss P and the reaction torque Tm.

（３）式中のＮは同期調相機１の回転数、Ｋは係数である。

In formula (3), N is the rotation speed of the synchronous phase modifier 1, and K is a coefficient.

FIG. 6 is a diagram showing the time course when the synchronous phase modifier 1 is freely rotated from the maximum rotation speed (Nn) under the condition that the excitation current is constant. The synchronous phase modifier 1 loses the energy of the repulsive loss P (kW=kJ/s) shown in FIG. 5 at the corresponding rotation speed, and the rotation speed decreases while maintaining the relationship of equations (1) and (2).

FIG. 7 is a diagram showing the time course of the rotation speed when the excitation current is changed in a certain rotation speed state, and shows that when the excitation current of the synchronous phase modifier 1 is increased, the reaction torque increases and the rotational energy is quickly lost. The slope of the rotation speed becomes steeper.
The rotation speed-reactive torque curve with the excitation current of the synchronous phase modifier 1 as a parameter shown in FIG. By calculating the rotational energy in , it is possible to predict the operation from a rotation speed higher than the synchronous speed of the synchronous phase modifier 1 to system synchronization.

Further, as described above, it is understood that the rate of decrease in the rotational speed of the synchronous phase modifier 1 can be increased or decreased by increasing or decreasing the excitation current of the synchronous phase modifier 1, and as a result, the voltage phase at the synchronous frequency can be adjusted.

Next, the voltage difference ΔV between the instantaneous voltage V _s of the power supply system and the instantaneous voltage V _t at the terminals of the synchronous phase modifier 1 before and after the synchronous rotation speed of the synchronous phase modifier 1 will be explained.
The instantaneous voltage _Vs of the power supply system is expressed by the following equation (4), and the instantaneous voltage _Vt at the terminals of the synchronous phase modifier 1 is expressed by the following equation (5).
Here, the synchronous phase modifier voltage is _Vt , and the automatic voltage regulator 24 of the synchronous phase modifier adjusts it to the grid voltage, so _Vs = _Vt = V.

ここで、
ω_ｓ＝２πｆ_ｓ、ω_ｔ＝２πｆ_ｔ
である。

here,
ω _s =2πf _s , ω _t =2πf _t
It is.

Before and after the synchronous rotation speed, the magnitude of the instantaneous voltage V _s of the power supply system and the instantaneous voltage V _t at the terminals of the synchronous phase modifier 1 are almost the same, so the voltage difference ΔV is mathematically expressed by the following equation (6). .

Examples of calculation of ΔV are shown in FIGS. 8 to 10. Three patterns are shown when the power supply system frequency f _s is 50 Hz and the synchronous phase modulator frequency f _t is 54 Hz.

In FIGS. 8 to 10, the waveform that changes with beats is the voltage difference ΔV, and the dotted line in FIG. 9 shows the envelope of ΔV. The frequency difference between the power system frequency f _s and the synchronous phase modulator frequency f _t |f _s - f _t |, for example, for 50 Hz and 54 Hz, Δf = 4 Hz, period T = 1/4 = 0.25 s, that is, , the voltage and phase match every 0.25 seconds.

Note that if the power system frequency f _s and the synchronous phase modulator frequency f _t are 50 Hz and 50.2 Hz, respectively, |f _s - f _t |=Δf=0.2 Hz, and T=1/0.2= Every 5 seconds, ie, every 5 seconds, the voltage difference envelope has a synchronization point of zero.
As mentioned above, the instantaneous voltages V _s and V _t are determined by the frequency difference between the power system frequency f _s and the synchronous phase modulator frequency f _t |f _s - f _t | Voltage and phase match.

CPUs used in various control devices such as the system joining device 20 and DSPs (Digital Signal Processors), which are characterized by signal processing, have become faster and more sophisticated in recent years, and the processing time for multi-point signals is 10 μs. Sampling and calculation processing can now be performed below. By the way, 10 μs corresponds to 0.18 degrees in electrical angle at 50 Hz, which is extremely small.
Furthermore, it is not difficult to obtain the envelope based on the Δf signal as described above, and mathematical operations can be easily performed using a CPU or a DSP.

As described above, the instantaneous voltage _Vs of the power supply system and the instantaneous voltage _Vt of the terminals of the synchronous phase modulator 1 are taken in by the system connection device 20, and the voltage difference ΔV is calculated at high speed. It becomes possible to estimate the instantaneous input timing of synchronization.

Figure 11 shows the movement of the voltage envelope (dotted line) when the frequency difference |f _s − f _t |, that is, Δf, gradually decreases, and the rotation speed of the synchronous phase modifier 1 decreases, causing the power supply system of the grid voltage to As the frequency ω _s approaches, the voltage envelope changes as shown in (a), (b), and (c) in FIG. Note that (a) represents a case where Δf is small, (b) represents a case where Δf is medium, and (c) represents a case where Δf is large.

Here, in reality, there is a delay time from when the system connection device 20 outputs a signal to the closing signal terminal of the parallel circuit breaker 4, and a delay until the parallel circuit breaker 4 receives the signal and the main contact turns ON. Since there is time, a command to close the parallel circuit breaker 4 is issued from the system connection device 20 in anticipation of this time.

Figure 12 shows the final voltage difference envelope, the "parallel circuit breaker closing command" output point (A) from the system connection device 20, and the actual "parallel circuit breaker closing" (that is, main contact ON) point (B). , is a sequence diagram showing the "synchronization estimation" point (C) (according to the envelope). In the figure, "with correction" indicates a period in which the excitation current is increased or decreased to change the reaction torque, and by repeating the presence and absence of excitation correction, the synchronization point where the voltage and phase of the power supply system 2 and the synchronous phase modifier 1 match is reached. Predict.
In addition, T1 in Fig. 12 is the delay time from when the system connection device outputs the signal to the closing signal terminal of the parallel circuit breaker, and T2 is the delay time until the parallel circuit breaker receives the signal and the main contact turns ON. Each represents a delay time (CB1 operation time).

FIG. 17 is a diagram showing the calculation contents of the system joining device 20 and the movement of the voltage phase difference before and after sending out the synchronous phase modifier input command, where the horizontal axis is time and the vertical axis is voltage. The point where the phase difference is written as 0 is the synchronization prediction point (C), and the grid connection device 20 issues a command so that the main circuit contact of the parallel circuit breaker 4 closes at the synchronization prediction point, but there is some movement. Even if there is a time error, the voltage is supplied within the permissible range of the voltage phase difference ±Φ.
In addition, in FIG. 17, the phase difference is expressed even after synchronization, but when the main circuit contact of the parallel circuit breaker 4 is closed, the synchronous phase modifier voltage V _g and the instantaneous voltage V _s of the power supply system have the same value. Therefore, V _s −V _g becomes zero (0 value).

FIG. 13 shows a sequence of system joining including speed-up of the starting inverter 10 controlled by the system joining device 20 according to the first embodiment. Compared to the sequence diagram of the comparative example shown in FIG. 2, the period of "operation using the starting inverter" remains the same, but the period of free rotation speed is controlled by the grid connection device 20 according to the first embodiment. It becomes part of the characteristic movement.

In contrast to the joining point 52 in the comparative example in FIG. It can also be seen that it is possible to close the parallel circuit breaker of the synchronous phase modifier 1 in a state where there is less fluctuation in the transient current.

As explained above, before and after joining the power supply system 2, the starting inverter 10 is disconnected and the parallel circuit breaker 4 is closed in a state where the starting inverter 10 is free rotating from a rotation speed higher than the rated rotation speed. In the phase modifier 1,
(a) The synchronous speed of the synchronous phase modifier 1 is determined based on the rotation speed-reactive torque curve of the synchronous phase modifier 1 with the rotation speed and excitation current of the synchronous phase modifier 1 as input information and the excitation current of the synchronous phase modifier 1 as a parameter. a first calculation module 20a that predicts a voltage envelope from a rotation speed higher than that to system synchronization;
(b) a second calculation module 20b that captures the instantaneous voltage of the power supply system and the instantaneous voltage of the terminals of the synchronous phase modifier 1 into the CPU 20c in the device, and predicts the timing at which both voltage phases match from the instantaneous voltage difference;
As described above, by using the first arithmetic module 20a and the second arithmetic module 20b built in the grid joining device 20, the synchronous adjustment can be performed from the estimation of the rotation speed and the phase of the synchronous phase modifier 1 by the grid joining device 20. It is possible to predict the phase difference at the timing of synchronization, including successive changes in the rotational speed of the phase machine 1.

Although it is possible to have both the first arithmetic module 20a and the second arithmetic module 20b and use them, the same applies even if only one of them is provided in the CPU 20c and used in order to simplify the function as much as possible. It has the effect of

Based on this prediction, the terminal voltage is corrected by the automatic voltage regulator 24 of the synchronous phase modifier 1, or the excitation current of the synchronous phase modifier 1 is corrected so that the phase difference when matching the system frequency is within the specified value. I do. If the excitation current of the synchronous phase modifier 1 and the phase difference at the time of synchronization are held within specified values so that the voltages eventually match, synchronization of the systems becomes possible.

Due to the above-described operation of the system joining device 20 according to the first embodiment, the joining point under the control of the system joining device 20 according to the first embodiment is It will be 51. An additional point 51 in the present disclosure is that the parallel circuit breaker of the synchronous phase modifier can be closed when the fluctuations in the transient voltage and current for the power supply system 2 are smaller. It is possible to reduce the phase difference when the timing is reached, which has the effect of avoiding synchronization failure.

In the description of the sequence diagram of FIG. 13, the scope of the present disclosure is the operation from free rotation to a rotation speed higher than the rated rotation speed to combination. Although the operation using the starting inverter 10 is described using the current type starting inverter 10, it is also possible to use a voltage type starting inverter 10 or a starting motor coupled to the shaft of the synchronous phase modifier 1. Similarly, it is possible to increase the rotation speed to a higher rotation speed than the rated rotation speed, and the system joining device 20 according to the present disclosure can be applied to this type of free rotation.

In addition, in FIG. 1 showing the system joining device 20 according to the present disclosure, the excitation device 5 of the synchronous phase modifier 1 has been described as thyristor excitation, but in the synchronous phase modulator 1 with brushless excitation, the free rotation of the synchronous phase modifier 1 The system joining device 20 according to the present disclosure is applicable.

Further, in FIG. 1, the connection point of the first potential transformer 14 is set to the secondary side of the main transformer 3, but even when the primary side of the main transformer 3 is used, the grid connection device 20 according to the present disclosure is applicable.

Furthermore, although the signal switch 26, adder/subtractor 27, and AVR controller 25 in the automatic voltage regulator 24 are shown in FIG. Apparatus 20 is applicable.

Embodiment 2.
In the system integration device according to the first embodiment, a case has been described in which the rotation speed is estimated using the design value of the synchronous phase modifier 1 or the measured value in the actual machine test as GD2 of the synchronous phase modifier 1, but the second embodiment In the system integration device according to By analyzing it, it becomes possible to correct the value of GD2.

The moment of inertia GD2 is basically expressed by rotational energy E and rotational angular velocity ω from equation (8), which is a modification of equation (7) below.

ここで、Ｋ_１は係数である。

Here, _K1 is a coefficient.

In the process in which the rotation speed of the synchronous phase modifier 1 reaches zero from free _rotation Eo, the value of GD2 at any time t _x is determined by Equation (8), where the energy at any time _t It can be calculated by respectively replacing ω _x with ω x.

In addition, if _Ex is used as the integrated value P _loss of the reaction loss P during free rotation, the relationship expressed by the following equation (9) is established. By using equation (9), it is possible to correct the value of the initial resistance loss P when attenuation from the free rotation state begins, so that more accurate phase prediction at the time of synchronization can be realized.

Since the integrated value P _loss of the resistance loss P during free rotation can be calculated in the system joining device 20, the value of GD2 can be calculated using equation (8).

By correcting the value of GD2 calculated by the above procedure, it is possible to further improve the accuracy of estimating the rotation speed of the synchronous phase modifier 1 by the system joining device 20, and as a result, it is possible to reduce synchronization failures, and to further improve the accuracy. This has the effect of saving labor for operators.

Embodiment 3.
In the system joining devices according to the first and second embodiments, regarding GD2, the value of GD2 is corrected by actually operating the synchronous phase modifier 1. By correcting the value of GD2, a database based on the repulsion loss curve provided in the system joining device 20 is corrected, and the change in the rotation speed of the synchronous phase modifier 1 is corrected based on this correction.

In addition to correcting GD2 by increasing the number of operations described in Embodiment 2, the system joining device according to Embodiment 3 also corrects GD2 as shown in the relationship between repulsion loss P and rotation speed of synchronous phase modifier 1 in FIG. 15. By correcting the database based on the resistance loss curve provided in the system joining device 20, it is possible to correct rotational speed changes due to age-related deterioration of bearings or increase in resistance loss due to grease depletion. As a result of being able to include aging deterioration in the prediction, it has the effect of improving synchronization accuracy.

Embodiment 4.
In the system integration devices for synchronous phase modifiers of Embodiments 1, 2, and 3, the synchronization prediction was improved.
In the system joining device of Embodiment 4, as shown in the block diagram of FIG. 16, the ratio of the resistance loss P _lossA obtained by operation and the conventional resistance loss P _lossB is calculated by a ratio calculator 81. The comparator 82 compares the value with the specified value of the reference device 83, and if it exceeds the specified value range, it can be determined that there is an abnormality in the bearing of the rotor of the synchronous phase modifier 1, and for example, an alarm is issued from the alarm device 84. This has the effect of saving labor for inspection work by workers.

Although this disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments may differ from those of a particular embodiment. The invention is not limited to application, and can be applied to the embodiments alone or in various combinations.

Accordingly, countless variations not illustrated are envisioned within the scope of the technology disclosed herein. For example, this includes cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with components of other embodiments.

1 Synchronous phase modifier, 2 Power system, 3 Main transformer, 4 Parallel circuit breaker, 5 Excitation device, 6 Field circuit breaker, 7 First excitation power supply breaker, 8 Second excitation power supply breaker, 9 Excitation transformer , 10 starting inverter, 11 output breaker, 12 starting input transformer, 13 auxiliary power transformer, 14 first instrument transformer, 15 second instrument transformer, 20 grid connection device, 20a first calculation module, 20b second calculation module, 20c CPU, 23 terminal voltage, 24 automatic voltage regulator, 25 AVR controller, 26 signal switch, 27 adder/subtractor, 28 auxiliary contact, 29 closing coil, 51 joining point in the present disclosure, 52 Merging point in comparative example, 81 Ratio calculator, 82 Comparator, 83 Standard device, 84 Alarm device

Claims (8)

A grid connection device that controls a synchronous phase modifier via an excitation device and a parallel circuit breaker,
higher than the synchronous speed of the synchronous phase modifier based on a rotation speed-reactive torque curve of the synchronous phase modifier with the rotation speed and excitation current of the synchronous phase modifier as input information and the excitation current of the synchronous phase modifier as a parameter. Equipped with a first calculation module that predicts the voltage envelope from the rotation speed to grid synchronization,
The first calculation module is used to correct the rotational speed of the synchronous phase modifier by increasing or decreasing the voltage at the terminals of the synchronous phase modifier or by increasing or decreasing the excitation current, thereby performing synchronous control of the synchronous phase modifier and interrupting the parallel connection. A system integration device characterized by controlling the input of equipment. A grid connection device that controls a synchronous phase modifier via an excitation device and a parallel circuit breaker,
The instantaneous voltage of the power supply system and the instantaneous voltage of the terminals of the synchronous phase modulator are taken, and the instantaneous voltage of the power supply system and the instantaneous voltage of the synchronous phase modulator are calculated based on the voltage difference between the instantaneous voltage of the power supply system and the instantaneous voltage of the terminals of the synchronous phase modifier. Equipped with a second calculation module that predicts the timing at which the instantaneous voltages at the terminals of the phase modulator become synchronized,
By correcting the rotation speed of the synchronous phase modifier by increasing or decreasing the number of terminals of the synchronous phase modifier or by increasing or decreasing the excitation current using the second calculation module, synchronous control of the synchronous phase modifier and the parallel circuit breaker are performed. A grid connection device characterized by performing input control. A grid connection device that controls a synchronous phase modifier via an excitation device and a parallel circuit breaker,
higher than the synchronous speed of the synchronous phase modifier based on a rotation speed-reactive torque curve of the synchronous phase modifier with the rotation speed and excitation current of the synchronous phase modifier as input information and the excitation current of the synchronous phase modifier as a parameter. a first calculation module that predicts a voltage envelope from rotation speed to system synchronization;
The instantaneous voltage of the power supply system and the instantaneous voltage of the terminals of the synchronous phase modulator are taken, and the instantaneous voltage of the power supply system and the instantaneous voltage of the synchronous phase modulator are calculated based on the voltage difference between the instantaneous voltage of the power supply system and the instantaneous voltage of the terminals of the synchronous phase modifier. Equipped with a second calculation module that predicts the timing at which the instantaneous voltages at the terminals of the phase modulator become synchronized,
By using both the first calculation module and the second calculation module to correct the rotation speed of the synchronous phase modifier by increasing or decreasing the voltage at the terminals of the synchronous phase modifier or by increasing or decreasing the excitation current, the synchronous phase modifier can be operated. A system integration device characterized by performing synchronous control and closing control of the parallel circuit breaker. The system integration device according to any one of claims 1 to 3, characterized in that a voltage at a terminal of the synchronous phase modifier is taken in as information on the rotation speed of the synchronous phase modifier. Claim 1, characterized in that each time the synchronous phase modifier is started, the accuracy of estimating the rotation speed of the synchronous phase modifier is improved by correcting the value of the moment of inertia GD2 by analyzing the transition of free rotation. The system integration device according to any one of 4 to 4. Every time the synchronous phase modulator is started, the free rotation transition is corrected based on the value of the moment of inertia GD2, as well as the excitation current, rotational speed, reaction torque, and resistance loss curve of the synchronous phase modifier. The system joining device according to any one of claims 1 to 4, wherein the accuracy of estimating the rotation speed is improved by correcting each numerical value. 7. The system integration device according to claim 6, wherein the repulsion loss curve is calculated from data on the repulsion torque and rotational speed of the synchronous phase modifier. The ratio of the repulsive loss P _lossA obtained each time the synchronous phase modifier is started and the repulsive loss P _lossB before obtaining the repulsive loss P _lossA is calculated, and if the ratio exceeds the specified value range, an abnormality is detected. The system joining device according to claim 6 or 7, characterized in that it determines that.

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