JPS6359733A - Safety device for generator - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is directed to a power system equipped with private power generation equipment,
The present invention relates to a generator safety device that performs power failure confirmation control in an external power system based on the presence or absence of current in a communication bus between the external power system and private power generation equipment.

[Conventional technology]

FIG. 2 shows a single line diagram of an electric power system having a conventional power failure confirmation/disconnection device. In the figure, reference numeral 1 denotes an external power system, which is connected via a breaker 2 to a power system having a private power generation facility 7. 3 is an instrument current transformer installed in the connecting bus, 4 is a current detector, 5 is a power failure confirmation disconnector, 6 is a breaker that connects the generator G to the load bus aBK, and 8 is the in-house power generation equipment 7. This is a transformer that detects the generated output voltage, and provides this generated output voltage to the voltage setting device 9. Reference numeral 10 denotes an automatic voltage regulator, which generates a voltage control signal based on the comparison difference between the detected voltage and the set voltage, and sends it to the field power supply device 12.

13 is a motor load, and 14 is a transformer load, which supplies power to the power equipment 16 via a switching device 15.

17 is an emergency power generation facility; 18 is a breaker for supplying power generated by the emergency power generation facility 17 to the power equipment 16 during a power outage on the load bus B; 19 is a control device for the emergency power generation equipment 17.

Next, the operation will be explained. The power outage confirmation disconnection device 5 constantly monitors the current of the communication bus A detected by the current detector 4, and when this current value reaches zero level, the in-house power generation equipment 7
Based on whether the power factor of the generator G in A signal (excitation increase command) is given to the voltage setter 9, and if the phase is slow, a control signal (excitation range command) for reducing the generator field current is given to the voltage setter 9. As a result, if the external power system 1 does not have a power outage,
The power generation output of the generator G increases and decreases, and therefore, assuming that there are no fluctuations in the load equipment such as the motor load 13 and the transformer load 14 and the power equipment 16, current flows through the communication bus A instead of no current. However, if the external power system 1 is out of power,
The connection bus A remains without current, and if this no-current period continues for a certain period of time or more, the power outage check disconnection device 5 determines that there is a power outage, issues a trip command to the connection breaker 2, and disconnects the external circuit breaker 2. The power system 1 and the private power generation equipment 7 are disconnected.

If the generator G is operated without disconnecting the external power system 1 and the private power generation equipment T, there is a risk that the external power system 1 will restore power without synchronizing with the generator G, resulting in asynchronous connection. It has sex.

On the other hand, the emergency power generation equipment 17 is normally stopped, and power is supplied to the power equipment 16 from the load bus B via the switching device 15. In the event of a power outage on the load bus B, the switch 15 receives a command from the control device 19 and switches to the emergency power generation equipment 17 side, the emergency power generation equipment 17 starts, and the breaker 18 is closed when the voltage is established. , the output of the emergency power generation equipment 17 will be supplied to the power equipment 16.

[Problem that the invention seeks to solve]

Since the conventional generator safety device is configured as described above, when the capacity of the load equipment and the generated output amount of the private power generation equipment 7 fluctuate slightly in an approximate state, the current flowing through the connecting bus A reaches the zero level. While this slight fluctuation state continues, the alternating excitation increase/decrease control by the power failure confirmation/disconnector 5 continues, resulting in an unfavorable disturbance state for the generator G. There was a problem that the unstable operation continued.

This invention was made to solve the above-mentioned problems, and aims to provide a generator safety device that can perform power outage disconnection control without continuing unstable operation of the generator. purpose.

[Means for solving problems]

The generator safety device according to the present invention detects whether or not the generator output increase/decrease control operation is repeated within a predetermined time by the power failure confirmation disconnection device, and performs a comparison 2 determination with a predetermined number of times,
A judgment/emergency generation command device was installed that outputs a command to start the emergency generation equipment and switch part of the load connected to the load bus from the load bus side to the emergency generation equipment side if the load exceeds the limit. It is something.

[For production]

The generator safety device according to the present invention activates the emergency power generation equipment when the capacity of the load equipment and the generated output of the private power generation equipment fluctuate slightly in an approximate state, and the current flowing through the connecting bus starts to fluctuate around the zero level. After startup, part of the load connected to the load bus is disconnected and connected to the emergency generator, and the current flowing through the connection bus is increased by the load capacity disconnected from the load bus. Keep the generator running stably.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. 1st
The figure is a single line diagram showing one embodiment of the present invention, and the difference in FIG. 1 from the conventional generator safety device shown in FIG. In the figure, the same components as those in FIG. 2 are given the same reference numerals and their explanations will be omitted.

Thus, the judgment/emergency power generation controller 20, together with the power failure confirmation/disconnection device 5, is a main part of the power generation safety device.

Next, the operation will be explained. The current flowing through the communication bus A is detected by the current detector 4, and the detection signal from the current detector 4 is then guided to the disconnection device 5.

This power failure confirmation/disconnection device 5 checks whether the current value input from the current detector 4 is at zero level or not, as explained with reference to FIG.
If the level is zero, an excitation increase command or an excitation range command is sent to the voltage setting device 9 according to the power factor of the generator G, and at the same time, it is stored that the excitation control command has been issued. . This excitation control increases or decreases the power generation output of the generator G, so the current value from the current detector 4 changes to a positive level. This resets the memory of the excitation control command. However, if the external power system 1 is out of power, the current from the current detector 4 remains zero, so if the no-current period continues for a certain period of time or more, the power outage confirmation disconnector 5 determines that there is a power outage. and issue a trip command for contact breaker 2. However, if the capacity of the load equipment such as the motor load 13 and the transformer load 14 and the generated output of the generator G continue to be approximated, the excitation control command will not be intermittent frequently, and the If the determination/emergency power generation command unit 20 detects that the excitation control command has been received a predetermined number of times or more, an operation start command is output to the emergency power generation equipment 170 control device 19. In response to this operation start command, the control device 19 starts the emergency power generation equipment 17, switches the switch 15, and after establishing the voltage, switches the power supply of the power equipment 16 to the load bus B.
control is performed so that the circuit breaker 18 is turned on by switching from the side to the emergency power generating equipment 17 side.

As described above, in this embodiment, when the current flowing through the connecting bus At--is slightly fluctuating around the zero level, if the increase and decrease control of the power generation output of the generator G is repeated more than a prescribed number of times within a prescribed time, The power supply to a part of the load equipment is switched to the power supply side of the emergency power generation equipment 17, and the current flowing through the communication bus A increases by the switched load capacity, so that the generator G
The repeated control to increase or decrease the power generation output is stopped, and the operation of the generator G becomes stable.

Note that in the above embodiment, a current detector is used, but
Instead of this, a power detector or a power direction detector may be used.

Furthermore, the power failure confirmation/disconnection device and the judgment/emergency power generation command device may be integrated into one unit.

〔Effect of the invention〕

As described above, according to the present invention, when the load capacity and the generator output fluctuate in an approximate state and the power failure confirmation disconnection device attempts to repeatedly control the increase/decrease in the generator output, the generator safety device is activated. In order to escape from the above-mentioned approximate state, part of the load is switched to power supply by the emergency power generation equipment, so the repetitive operation of increasing and decreasing the power generation output of the generator is stopped, and reliable power failure confirmation and disconnection control can be performed.

[Brief explanation of the drawing]

FIG. 1 is a single line diagram of a power system including a generator protection device according to an embodiment of the present invention, and FIG. 2 is a single line diagram of a power system including a conventional power failure confirmation control device. In the figure, 1 is the external power system, 2 is the connection breaker, and 5
is a power outage confirmation disconnection device, γ is a private power generation facility, 17 is an emergency power generation facility, 20 is a judgment/emergency power generation command device, A is a communication bus, and G is a generator. In addition, in the figures, the same reference numerals indicate the same or equivalent parts. 1st! ! I 7: Self-discharge shoulder / 7: Back 1ff WSVT late M 20: Force 1 constant / η field response power reception 1 response A 2 consecutive routes great grandson 8 2 tributes visit the 祿

Claims (1)

[Claims] When the current value flowing through the connection bus that connects the generator of the private power generation equipment and the external power system reaches zero level, the power output of the generator is increased or decreased by a power failure confirmation disconnector for a predetermined period of time. In the generator safety device, the power outage confirmation parallel disconnection device opens the connection or disconnection in the communication bus when it is detected that the current value does not flow. When the number of repetitions of the increase/decrease control operation of the power generation output of the machine within a predetermined period of time is greater than or equal to the specified number of times, the emergency power generation equipment is activated, and a part of the load equipment connected to the load bus is activated from the load bus side. A generator safety device characterized by comprising a judgment/emergency power generation command device that outputs a command to switch to a power generation equipment side.