JP5101148B2 - Automatic synchronization method - Google Patents

Description

  The present invention relates to an automatic synchronization method for synchronizing a plurality of synchronous generators in a no-load state.

The plurality of synchronous generators as described above are used, for example, as an emergency power supply facility, and when a synchronous start to the power load of these synchronous generators is input with a power generation start command accompanying a power failure , After synchronizing a plurality of synchronous generators in a no-load state, turning on the input side switch that opens and closes the input side of the power load, and starting the supply of power to the power load .
And as a synchronization method of such a plurality of synchronous generators, a forced synchronization method of forcibly turning on each output-side switch in a state where the respective rotation speeds and respective output voltages of the plurality of synchronous generators are matched. In addition, there is an automatic synchronization method that automatically completes synchronization using an automatic synchronization input device (see, for example, Patent Documents 1 and 2).

  In the automatic synchronization method of Patent Document 1 described above, after each output-side switch of a plurality of synchronous generators is turned on and each output side is connected in parallel and each rotational speed is increased, each of the plurality of synchronous generators is The output voltage is raised relatively slowly along the ramp command gradient. Then, a cross current is generated between the plurality of synchronous generators due to the difference in the frequency, voltage, and phase of the output power, and the synchronization force works, and the synchronization is automatically completed by the synchronization force.

  On the other hand, in the automatic synchronization method of Patent Document 2, the output-side switches of a plurality of synchronous generators are turned on, the output sides are connected in parallel, and the number of rotations is increased to a predetermined number of rotations. The respective excitation currents of the synchronous generators are increased to bring the plurality of synchronous generators into an excited state. Then, like the above-mentioned Patent Document 1, a synchronization force works between the plurality of synchronous generators, and synchronization is performed by the synchronization force. After that, when each rotation speed of the plurality of synchronous generators is increased from the predetermined rotation speed to the rated rotation speed, each output voltage is increased to the rated voltage to complete the synchronization.

Japanese Patent Laid-Open No. 55-8233 Japanese Patent Laid-Open No. 61-244231

In the automatic synchronization method described in Patent Document 1, since the output voltages of the plurality of synchronous generators are increased relatively slowly, the synchronization required time required to complete the synchronization becomes longer, for example, a power failure It was not possible to start supplying power to an important power load instantly after this occurred.
Furthermore, it is necessary to employ a complicated configuration in which a ramp function voltage command device for increasing each output voltage along the ramp command gradient is installed for each of the plurality of synchronous generators.

  Further, in the automatic synchronization method described in Patent Document 2, it is necessary to increase each rotation speed and each output voltage to a rated value after increasing and synchronizing each excitation current of a plurality of synchronous generators. Therefore, similar to the above-mentioned Patent Document 1, the time required for synchronization becomes longer.

  In addition, in the conventional automatic synchronization method, the power supply to the power load is started after the synchronization of the plurality of synchronous generators is completely completed, for example, while performing the synchronization, If the reactive power cannot be suppressed due to a field circuit failure, etc., or if a reverse current is generated due to a motor failure, etc. As a result, there is a problem that it becomes impossible to start power supply to the power load.

  The present invention has been made in view of the above problems, and its purpose is to reduce the synchronization time required to complete the synchronization with a relatively simple configuration and cause a power failure. An object of the present invention is to provide an automatic synchronization method capable of instantly starting power supply to an important power load.

In order to achieve the above object, an automatic synchronization method according to the present invention is an automatic synchronization method for synchronizing a plurality of synchronous generators in a no-load state, and the first characteristic configuration is the plurality of synchronous power generations A speed increasing step for increasing each speed of the machine to the rated speed;
Input each output side switch that opens and closes each output side of the plurality of synchronous generators, an output side switch input step that connects each output side of the plurality of synchronous generators in parallel,
The voltage command value of each automatic voltage regulator of the plurality of synchronous generators is simultaneously set to the rated voltage, and the output voltage setting step of setting each output voltage of the plurality of synchronous generators to the rated voltage is sequentially executed. In the point.

According to the first characteristic configuration, by executing the output voltage setting step after performing the rotation speed increasing step and the output side switch closing step, the cross current generated between the plurality of synchronous generators Synchronization power works, and synchronization can be completed automatically by the synchronization power.
In the output voltage setting step, the output voltages of the plurality of synchronous generators are not gradually increased. For example, the output voltages are set relatively with a relatively simple configuration using only the characteristics of the automatic voltage regulator. Each output voltage is set to a predetermined voltage in such a manner that it suddenly increases (for example, 2 seconds). Then, it is possible to complete the synchronization of the plurality of synchronous generators relatively instantaneously while keeping the increase in the synchronization force for the plurality of synchronous generators and the increase in the load due to the increase in output voltage within the allowable range.
Therefore, with such a relatively simple configuration, the synchronization time required to complete the synchronization is shortened, and power to an important power load is instantaneously (eg within 40 seconds) after a power failure occurs. An automatic synchronization method that can start the supply can be realized.

The second characteristic configuration of the automatic synchronization method according to the present invention, in addition to the first feature structure, the later performs a rotation speed increase step, the rotational speed does not converge to or rated rotational speed does not reach the rated speed specified An output side switch insertion prohibiting step for prohibiting input of the output side switch is executed for the synchronous generator.

After execution of the rotation speed increasing step, a phenomenon occurs in which any of the plurality of synchronous generators does not reach the predetermined rotation speed or converge to the predetermined rotation speed due to an increase in the burden due to the increase in output voltage. There is a case.
Therefore, according to the second feature configuration, by executing the output side switch entry prohibiting step for the specific synchronous generator in which such an abnormal phenomenon of the rotational speed has occurred, another synchronous generator Only, the output side switch input step and the output voltage setting step are executed to complete the synchronization, and then the power to the power load only from the synchronous generator in which the output side switch is input Supply can be started.

  According to a third characteristic configuration of the automatic synchronization method of the present invention, in addition to any one of the first to second characteristic configurations, each of the plurality of synchronous generators after executing the output voltage setting step. In addition, the reactive power is adjusted by bias-controlling the output voltage, and the control step of adjusting the active power by bias-controlling the rotation speed is executed.

  According to the third feature configuration, after executing the output voltage setting step, the control step is executed in each of the plurality of synchronous generators to adjust the output voltage and active power for adjusting reactive power. By controlling the number of rotations for each of the above, the cross current flowing between the plurality of synchronous generators can be quickly suppressed, and the power can be supplied to the power load quickly.

  According to a fourth feature configuration of the automatic synchronization method of the present invention, in addition to any one of the first to third feature configurations, the specific feature that is in an abnormal state after executing the output voltage setting step. An output side switch opening step of opening the output side switch is executed for the synchronous generator.

  According to the fourth characteristic configuration, when any of the plurality of synchronous generators is in an abnormal state after the output voltage setting step is performed, the specific synchronous generator in the abnormal state On the other hand, by executing the output side switch entry prohibition step, it is assumed that synchronization has been completed only for the other synchronous generators, and then only from the synchronous generator in which the output side switch is turned on. Power supply to the power load can be started.

  According to a fifth feature configuration of the automatic synchronization method of the present invention, in addition to the fourth feature configuration, the abnormal state is caused by a field circuit abnormal state detected by a value of reactive power, or generation of reverse power. It is in the point which is the rotation speed abnormal state detected.

  According to the fifth characteristic configuration, as the abnormal state of the synchronous generator, a field circuit abnormal state in which the reactive power value cannot be suppressed to a normal value due to failure of the field circuit, or synchronous power generation The rotation speed abnormality state in which the rotation speed of the prime mover driving the machine does not converge to the predetermined rotation speed and a reverse current is generated can be detected by the value of the effective power and the rotation speed.

  An embodiment of an automatic synchronization method according to the present invention will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a power generation system that executes the automatic synchronization method.

  When a power generation start command is input due to a power failure, such a power generation system executes an automatic synchronization method for synchronizing a plurality of synchronous generators 10 in a no-load state, and then performs an important load 41, a general load 43, etc. The input side switches 40 and 42 for opening and closing the input side of the power load are turned on, and the supply of power to the power loads 41 and 43 is started. Hereinafter, the configuration provided for each of the plurality of synchronous generators 10 will be described.

  The synchronous generator 10 is rotationally driven by a prime mover 11 such as an internal combustion engine. The control device 20 such as a sequencer is configured to maintain the rotational speed of each prime mover 11 at the rated rotational speed by executing the opening degree control of the governor 12 during operation of the prime mover 11.

The output side of the synchronous generator 10 is provided with a transformer 16 that detects an output voltage, an output side switch 13 that opens and closes the output side, and a current transformer 14 that detects an output current. Each of the plurality of synchronous generators 10 is connected in parallel to the downstream side of the current transformer 14, and the connection line is connected to the power loads 41 and 43 side.
The power load includes an important load 41 that should supply power even in the event of a power failure and a general load 43 that does not need to supply power in the event of a power failure. Each input side switch 41, 42 is arranged so as to be supplied to 41.

A meter device 15 for detecting reactive power and active power from the output voltage detected by the transformer 16 and the output current detected by the current transformer 14 is provided.
In addition, an automatic voltage regulator (hereinafter referred to as “AVR”) 18 connected to the field circuit 17 of the synchronous generator 10 is provided. The AVR 18 converts the output voltage detected by the transformer 16. Compared with the voltage command value from the control device 20, the field current of the synchronous generator 10 is adjusted so that the deviation becomes zero.

  Further, a bias control circuit 19 that outputs a bias signal based on the active power and the reactive power detected by the meter device 15 is provided. In other words, the bias control circuit 19 outputs a bias signal based on the generated voltage detected by the meter device 15 to the AVR 18 to control the output voltage to adjust the reactive power to a predetermined value, and 12 is configured to output a bias signal based on the active power detected by the meter device 15 to adjust the effective power by bias-controlling the rotational speed.

  And the automatic synchronization method for synchronizing the some synchronous generator 10 comprised as mentioned above in a no-load state is performed by each control apparatus 20 of the said some synchronous generator 10, The processing flow Is described below.

When a power generation start command is input along with a power failure, first, a rotation speed increasing step for increasing each rotation speed of each synchronous generator 10 to the rated rotation speed is executed, and then each of the plurality of synchronous generators 10 is Each output side switch 13 for opening and closing the output side is turned on, and an output side switch making step for connecting the output sides of the plurality of synchronous generators 10 in parallel is executed.
In this speed increase step, the operation of each prime mover 11 of the plurality of synchronous generators 10 is started, and further, the opening degree of the governor 12 is controlled, and the speed of each prime mover 11 is increased to a predetermined rated speed. Maintained.

Here, after the rotation speed increase step as described above is executed, the rotation speed of the prime mover 11 does not reach the predetermined rated rotation speed even if the opening degree of the governor 12 is controlled due to an increase in the burden due to the increase in output voltage. Or it may not converge to the rated speed. Therefore, an output side switch insertion prohibiting step is executed for such a specific synchronous generator 20, and the output side switch 13 is prohibited from being input by the output side switch input step.
Further, for the synchronous generator 10 for which the output side switch 13 is prohibited from being input, the prime mover 11 is stopped, and an alarm or the like reporting an abnormality is output.
On the other hand, for the synchronous generator 10 in which the input side switch 13 is not prohibited, the subsequent steps continue without waiting for the recovery of the synchronous generator 10 in which the output side switch 13 is prohibited. Therefore, the start of power supply to the power loads 41 and 43 is not delayed.

Next, an output voltage setting step for simultaneously setting each output voltage of the plurality of synchronous generators 10 detected by each transformer 16 to a predetermined voltage is executed.
Then, when the phase of each output voltage is different, a cross current flows between a plurality of synchronous generators 10 to generate a synchronizing force, and the synchronous generator 10 on the phase advance side serves as a generator. The synchronized generator 10 on the delayed side acts as an electric motor, and the phases of the plurality of synchronized generators 10 are automatically matched to complete the synchronization.

Further, in this voltage setting step, the voltage command value input to each AVR 18 is not gradually increased, but the voltage command value is set to the rated voltage all at once, so that each AVR 18 is detected by each transformer 16. The output current is compared with the rated voltage, and the field current of each synchronous generator 10 is adjusted so that the deviation becomes zero, so that each output voltage of the plurality of synchronous generators 10 is relatively short, for example, 2 seconds. To increase the rated voltage.
Then, the synchronization of the plurality of synchronous generators 10 is completed relatively instantaneously while keeping the increase in the synchronization force and the burden due to the increase in output voltage within the allowable range.
Even when the rate of increase of each output voltage is longer than 2 seconds as described above, there is almost no effect of reducing the burden on the plurality of synchronous generators 10. On the other hand, if the ascending speed is too short, such as about 1 second, the burden becomes too great, and there is a concern about deterioration of the synchronous generator 10 and the prime mover 11. Therefore, it is considered that the increase rate of each output voltage is about 2 seconds.

In addition, after executing the output voltage setting step, as described above, each bias control circuit 19 executes a control step for bias control of each output voltage and each rotation speed, and each effective voltage in the plurality of synchronous generators 10 is determined. The power and each reactive power are adjusted.
Therefore, the cross current flowing between the plurality of synchronous generators 10 can be quickly suppressed, and the power supply to the power loads 41 and 43 can be started by quickly turning on the input side circuit breakers 40 and 42.

Furthermore, after executing the output voltage setting step, when the value of the reactive power detected by the meter device 15 exceeds a predetermined threshold by the control device 20 due to a failure of each field circuit 17 or the like, The synchronous generator 10 is determined to be in a field circuit abnormal state, and when the output current detected by the current transformer 14 is negative due to a failure of each prime mover 11, that is, a reverse current is generated. When it is, it is determined that the synchronous generator 10 has an abnormal rotation speed.
And each control means 20 opens the output side switch 13 with respect to the specific synchronous generator 10 determined to be in an abnormal state such as the field circuit abnormal state or the rotational speed abnormal state. An output side switch opening step is executed.
Moreover, about the synchronous generator 10 by which the output side switch 13 was open | released, the motor | power_engine 11 is stopped and the alarm etc. which report abnormality are output.
On the other hand, for the synchronous generator 10 in which the output side switch 13 is not opened, the operation is continued and the input side circuit breaker 40, without waiting for the recovery of the synchronous generator 10 in which the output side switch 13 is opened. By supplying 42, power supply to the power loads 41 and 43 is quickly started.

  The automatic synchronization method of the present invention is a method of synchronizing a plurality of synchronous generators in a no-load state, and further reduces the synchronization time required to complete the synchronization with a relatively simple configuration. Thus, it can be effectively used as a method capable of starting power supply to an important power load instantly after a power failure occurs.

Schematic configuration diagram of a power generation system that executes an automatic synchronization method

Explanation of symbols

10: Synchronous generator 13: Output side switch 40, 42: Input side switch

Claims (5)

An automatic synchronization method for synchronizing a plurality of synchronous generators in a no-load state,
A rotation speed increasing step for increasing each rotation speed of the plurality of synchronous generators to a rated rotation speed;
Input each output side switch that opens and closes each output side of the plurality of synchronous generators, an output side switch input step that connects each output side of the plurality of synchronous generators in parallel,
The voltage command value of each automatic voltage regulator of the plurality of synchronous generators is simultaneously set to the rated voltage, and the output voltage setting step of setting each output voltage of the plurality of synchronous generators to the rated voltage is sequentially executed. Automatic synchronization method. Wherein after executing the rotation speed increase step, the rotational speed does not reach the rated speed, or to a particular of the synchronous generator does not converge to rated speed, the output side switch-on prohibiting the insertion of the output-side switch The automatic synchronization method according to claim 1, wherein the prohibiting step is executed.   After executing the output voltage setting step, in each of the plurality of synchronous generators, a control step of adjusting the reactive power by bias-controlling the output voltage and adjusting the active power by bias-controlling the rotation speed The automatic synchronization method according to claim 1 or 2, which is executed.   The output side switch opening step for opening the output side switch is executed for the specific synchronous generator in an abnormal state after the output voltage setting step is executed. The automatic synchronization method according to one item.   5. The automatic synchronization method according to claim 4, wherein the abnormal state is a field circuit abnormal state detected by a value of reactive power or a rotational speed abnormal state detected by generation of reverse power.

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