JPH07159592A - Power source control device for bus with mg set and power source control method - Google Patents

Abstract

PURPOSE:To prevent the inertial energy of an MG set from being consumed by electric loads other than the load connected to the MG set. CONSTITUTION:A bus 3 is connected to a power source 1a and an alternate power source 1b via power receiving circuit breakers 2a, 2b. Electric loads 9a,..., 9z and the induction motor 6a of an MG set via a circuit breaker 4 are connected to the bus 3, and a load 7 is connected to the generator 6b of the MG set. When the circuit breakers 2a, 2b are opened, they are detected by detectors 11a, 11b respectively, an AND circuit 12 judges that both detectors 11a, 11b detect the opening of the circuit breakers 2a, 2b, and a time limit circuit 13 outputs an instruction 14 to a circuit breaker circuit 15 when the judged result is continued for a prescribed period. When the circuit breaker circuit 15 receives the instruction 14, it releases the circuit breaker 4 to cut off the MG set from the bus 3. The inertial energy of the MG set to be consumed by the load 7 can be prevented from being consumed by the electric loads 9a,..., 9z.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power supply system that uses rotary inertia energy stored in an MG set to supply power to a load connected to the MG set for a certain period of time even when a commercial power supply is lost. The present invention relates to a power supply control device and a power supply control method suitable for effectively using the inertial energy stored in the MG set when the commercial power supply is lost.

[0002]

2. Description of the Related Art When an instantaneous power failure or a power failure occurs in a commercial power source, the power supply to the electrical load is not instantaneously interrupted by an M power supply between the important electrical load and the commercial power source bus.
G set is provided. This MG set stores mechanical inertial energy with the commercial power supply when the commercial power supply is normal, and converts this rotational energy into electric energy with the generator of the MG set at the time of momentary power failure, etc., to supply power to important equipment. It is maintained for a certain period of time. Since the MG set needs to retain a large amount of inertial energy, it often has a flywheel. The MG set constitutes a kind of energy conversion device in which electric energy supplied from a commercial power source is temporarily converted into mechanical energy by an electric motor and then converted into electric energy by a generator. The method of supplying power to the MG set and the method of controlling load on the busbar are the same as those for a normal electric load, and power is supplied from the busbar through a circuit breaker. Incidentally, as related to the prior art, Japanese Patent Laid-Open No.
There is a -203997 issue.

[0003]

The above-mentioned prior art is based on the MG
In a configuration in which the set and another electric load are connected to the same bus, and an important electric load is connected to the MG set, when the bus is disconnected from the power supply, the MG set is not the electric load connected to itself. , The electric power is exchanged with another electric load connected to the bus bar through the bus bar, and the accumulated inertial energy of the MG set is not the original important electric load but another electric load via the bus bar. It does not consider the possibility of giving The induction motor that constitutes the MG set can operate as a generator for a while due to the residual magnetic flux of the secondary circuit even after the power supply is lost. Therefore,
When the other electric loads are electric motors or static power converters having particularly small inertia, electric power may be supplied from the MG set to these loads via the bus bar, and inertia energy may be consumed. As a result, there arises a problem that the mission of the MG set, that is, the function of “supplying inertial energy as a power source to the downstream side connected load at the time of power failure” is deteriorated. In order to avoid this problem, it is conceivable to separate the MG set from the feeder buses of other electric loads, but there is a problem in that the number of buses increases, which causes an increase in power supply equipment.

An object of the present invention is to provide a power supply control device and a power supply control method capable of preventing or reducing the deterioration of the function of the MG set even when the MG set and other electric loads are supplied from the same bus. It is in.

[0005]

The above object is to electrically disconnect the MG set from the bus bar when it is detected that the bus bar is disconnected from the power supply and is not connected to any of the power sources that can receive power. Is achieved.

The above object is also to monitor the direction of power flow in the feeder from the bus bar to the MG set, and when it detects that the direction has changed from the MG set to the bus line, the MG set is electrically disconnected from the bus line. Achieved by disconnecting.

The above object is also achieved by monitoring the number of revolutions of the MG set or the generator output frequency and disconnecting the MG set from the bus bar when it detects a drop above a certain value.

[0008]

The function of disconnecting the bus bar from the power supply can be detected by checking whether the power receiving / interrupting circuit of the bus bar is open. M
By electrically disconnecting the G set from the bus bar, the power supply path from the MG set to another electric load via the bus bar is cut off. As a result, all the inertial energy of the MG set is supplied to the original electric load connected to the downstream side of the MG set.

The direction of the electric power between the bus bar and the MG set can be detected by a reverse power relay that inputs voltage and MG set drive motor current. In addition, the MG set inertial energy is M
It can be estimated by the rotation speed of the G set or the frequency of the MG set generator output. If electric power is supplied from the MG set to another electric load via the bus bar, the rotation speed of the MG set and the frequency of the generator will decrease. Therefore, when a certain amount of decrease is detected, the MG set will be connected to the bus bar. It is possible to reduce the consumption of inertial energy.

[0010]

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 power supply configuration and power supply control block configuration diagram according to the first embodiment of the present invention. Bus 3 is normally
Power is supplied from the commercial AC power supply 1a via the power receiving circuit breaker 2a. The bus bar 3 is further configured to be able to receive power supply from the alternative AC power supply 1b via the alternative power supply power receiving and breaking circuit 2b. The bus bar 3 feeds power to the MG set drive motor 6a via the MG set feed breaker 4 and the feeder 5. The bus bar 3 also feeds electric loads 9a and 9z, respectively, via feeder breakers 8a and 8z.

The MG set drive motor 6a drives the MG set generator 6b, and the electric power generated by the MG set generator 6b is supplied to the load 7 of the MG set. Power breaker 2
The circuit breaker open position detectors 11a and 11b for detecting the open state of the circuit breaker are installed in the a and the alternative power receiving breaker 2b, respectively. The signals from the circuit breaker open position detectors 11a and 11b are used by the AND circuit 12 to determine whether both circuit breakers are open. The determination signal becomes a circuit breaker open command 14 and is transmitted to the circuit breaker 15 when the time limit circuit 13 continues for a time longer than a predetermined time. For example, when the power supply 1a that supplies power to the bus 3 is down, the circuit breaker 2a is opened and the circuit breaker 2b is closed, and the alternative power supply 1b is switched. If it takes 0.1 to 0.2 seconds to switch between the circuit breakers 2a and 2b, there is a moment during which the circuit breakers 2a and 2b are both opened. At this moment, in order not to erroneously determine that both power supplies 1a and 1b are down, the time delay circuit 13 waits, for example, 0.3 seconds, and even after 0.3 seconds, both circuit breakers 2a and 1b
Only when both 2b are open, it is judged that both the power supplies 1a and 1b are disconnected from the bus bar 3, and the time limit circuit 13 outputs the control signal 14 to the interruption circuit 15. The cutoff circuit 15 receiving the control signal 14 cuts off the MG set feed breaker 4 and disconnects the MG set from the bus 3.

When the bus bar 3 cannot actually be supplied with power from either the AC power supply 1a or the alternative AC power supply 1b, the power receiving breaker 2a and the alternative power receiving breaker 2b are provided.
Both are open. Therefore, the circuit breaker open position detector 1
Both 1a and 11b operate, whereby the output of the AND circuit 12 is in an operating state, and when this continues for a certain period of time, the time limit circuit 13 instructs the interruption circuit 15 to issue a circuit breaker open command 1
4 is given and the MG set feed breaker 4 is opened.
As a result, the MG set drive motor 6a is electrically disconnected from the bus bar 3, and the other electric loads 9a connected to the bus bar 3,
Power is prevented from being supplied to the 9z from the MG set via the bus 3.

According to the present embodiment, the time setting of the time delay circuit is set in consideration of the bus switching time to the alternative power supply at the time of power loss in the normal time, so that the power control circuit of the present invention is provided only when the bus switching fails. Has an effect that the MG set can be separated from the bus bar. This embodiment does not require a special detector, can be realized by a simple circuit that uses only the position signal of the circuit breaker, and has an effect of low cost.
Also, considering the switching time of the power receiving power source, there is no malfunction in normal bus operation.

The BWR (Boiling Water Reactor) recirculation pump has its own inertia energy due to its large capacity, and even if the power source is disconnected from the bus bar, it continues to rotate with the inertia energy, so there is no problem. In the improved ABWR, the internal pump used as the recirculation pump has a small capacity, so that it immediately stops when the power supply is cut off, and there is a possibility that the reactor water level may fluctuate more than necessary. Therefore, MG
By connecting the set to the busbar, connecting the internal pump as an electric load of the MG set, and further applying the above-described embodiment, it is possible to suppress unnecessary fluctuations in the reactor water level even when the power is cut off, Can be safely stopped.

FIG. 2 is a configuration diagram of a power supply and a power supply control block according to the second embodiment of the present invention. The power supply configuration in FIG. 2 is the same as that in FIG. 1, but in the present embodiment, the feeder 5 from the bus bar 3 to the MG set drive motor 6a is provided with a current transformer 21 for detecting a current, and the bus bar is also provided. 3 is provided with a voltage transformer 22 for detecting the voltage. The outputs of the current transformer 21 and the voltage transformer 22 are input to the reverse power relay 23, and when the direction of the electric power in the feeder 5 is from the MG set drive motor 6a to the bus bar 3, the reverse power relay 23 operates. To do. The operation signal is given to the time limit circuit 24, and when the operation of the reverse power relay 23 continues for a certain time or longer, the breaker circuit open command 14 is given to the breaker circuit 15. As a result, the MG set feeding breaker 4 is cut off, and the MG set driving motor 6a is electrically disconnected from the bus bar 3.

According to this embodiment, in order to directly detect the power outflow from the MG set to another electric load, which is the cause of the problem to be solved by the present invention, the MG set is connected to the same bus of inertia energy. This has the effect of minimizing consumption by other electric loads.

FIG. 3 is a configuration diagram of a power supply and a power supply control block according to the third embodiment of the present invention. The power supply configuration in FIG. 3 is the same as that in FIG. 1, but in this embodiment,
The number of revolutions of the MG set is detected by the pulse generator 31 proportional to the number of revolutions, converted into a number of revolutions signal by the signal converter 32, and then compared with the set value of the setter 34 by the comparator 33 to determine the number of revolutions. When the voltage becomes lower than the set value, the shutoff circuit 1
A circuit breaker open command 14 is issued to the switch 5. This allows MG
The set feed breaker 4 is cut off, and the MG set drive motor 6a is electrically disconnected from the bus bar 3. In this embodiment, the MG set rotation speed is detected, but the same configuration is obtained even if the MG set output frequency is detected.

According to the present embodiment, since the amount proportional to the rotational inertia energy of the MG set is directly detected, the inertia energy above a certain value should be limited so as not to be consumed by other electric loads connected to the same bus. There is an effect that can be.

[0019]

According to the present invention, even when the MG set and other electric loads are supplied from the same bus, when the power supply to the bus is lost, the power of the rotary inertia energy accumulated in the MG set is transmitted via the bus. It is possible to prevent or reduce the consumption due to the electric load, and to surely guarantee the power supply capacity for the load of the MG set.

[Brief description of drawings]

FIG. 1 is a power supply and control block diagram showing a configuration of a first embodiment of the present invention.

FIG. 2 is a power supply and control block diagram showing a configuration of a second embodiment of the present invention.

FIG. 3 is a power supply and control block diagram showing a configuration of a third embodiment of the present invention.

[Explanation of symbols]

1a ... AC power supply at normal time, 1b ... Alternative AC power supply, 2a, 2
b ... Power receiving breaker, 3 ... Bus bar, 4 ... MG set feeding breaker, 5 ... Feeder, 6a ... MG set driving motor, 6b
… MG set generator, 7… MG set load, 8a, 8
z ... load feeder breaker, 9a, 9z ... other electric loads,
11a, 11b ... Circuit breaker open position detector, 12 ... AND circuit, 13 ... Time limit circuit, 14 ... Circuit breaker open command signal, 15 ...
Breaking circuit, 21 ... Current transformer, 22 ... Voltage transformer, 23 ... Reverse power relay, 24 ... Time limit circuit, 31 ... Pulse generator, 3
2 ... Signal converter, 33 ... Comparator, 34 ... Setting device.

Claims (13)

[Claims] 1. A power supply facility in which power is supplied from one bus bar to an MG set and at least one electric load, and the bus bar can receive power from one or a plurality of power sources, in which power supply the bus bar is. And a means for detecting that the bus bar is not receiving power, and a means for disconnecting the MG set from the bus bar when it is detected that the bus bar is not receiving power from any power source. Power supply control device for the busbar. 2. In the power supply facility, wherein one bus bar supplies power to the MG set and at least one electric load, and the bus bar can receive power from one or more power sources, the MG set and the bus bar. Means for detecting a direction of electric power flowing between the MG set and the M direction when the means detects that electric power is flowing from the MG set in the bus line direction.
And a means for disconnecting the G set from the bus bar. 3. The number of revolutions of the MG set in a power supply facility in which power is supplied from one bus to the MG set and at least one electric load, and the bus can receive power from one or more power sources. Alternatively, a bus bar having an MG set, characterized by including means for detecting an output frequency, and means for disconnecting the MG set from the bus bar when the rotational speed or the output frequency detected by the means becomes equal to or less than a set value. Power control device. 4. In a power supply facility comprising an electric load and an MG set which are supplied with power from a bus bar connected to a power supply, and an electric load which is supplied with power from the MG set, the connection between the power supply and the bus bar is cut off. A method of controlling power supply, characterized in that the MG set is disconnected from the bus bar when the power is applied. 5. The power supply control method according to claim 4, wherein the MG set is disconnected from the bus bar when a disconnection state between the power supply and the bus bar continues for a predetermined time. 6. A power supply facility comprising an electric load and an MG set which are supplied with power from a bus bar connected to a power source, and an electric load which is supplied with power from the MG set, wherein power is supplied from the MG set in the bus bar direction. A power supply control method, which comprises disconnecting the MG set from the bus bar when a flow occurs. 7. The power supply control method according to claim 6, wherein the MG set is disconnected from the bus when the flow of electric power from the MG set toward the bus continues for a predetermined time. 8. In a power supply facility including an electric load and an MG set that are supplied with power from a bus connected to a power source, and an electric load that is supplied with power from the MG set, the number of revolutions or the output frequency of the MG set is A power supply control method, wherein the MG set is disconnected from the bus bar when the value is below a set value. 9. The electric load according to claim 4, wherein the electric load supplied with power from the MG set is an ABW.
A power supply control method, which is an R internal pump. 10. A first power source, a second power source for substitution, a bus bar, a first circuit breaker for connecting / disconnecting the first power source and the bus line, a second power source and the bus line. The second circuit breaker for connecting and disconnecting, the MG set, the busbar and the MG
A third circuit breaker for connecting and disconnecting with a set, at least one first electric load connected to the busbar, and the MG
A second electric load connected to the set, and means for outputting an opening command to the third circuit breaker when both the first circuit breaker and the second circuit breaker have been kept open for a predetermined time. A power supply control device for a bus having a characteristic MG set. 11. A first power supply, a second power supply for substitution, a bus bar, a first circuit breaker for connecting / disconnecting the first power supply and the bus bar, a second power supply and the bus bar. The second circuit breaker for connecting and disconnecting, the MG set, the busbar and the MG
A third circuit breaker for connecting and disconnecting with a set, at least one first electric load connected to the busbar, and the MG
A second electrical load connected to the set, the busbar and the M
Means for detecting the direction of electric power flowing between the G set,
MG for outputting an opening command to the third circuit breaker when the means continuously detects a flow of electric power from the MG set in the busbar direction for a predetermined time.
Bus power supply controller with set. 12. A first power supply, a second power supply for substitution, a bus bar, a first circuit breaker for connecting and disconnecting the first power supply and the bus bar, a second power supply and the bus bar. The second circuit breaker for connecting and disconnecting, the MG set, the busbar and the MG
A third circuit breaker for connecting and disconnecting with a set, at least one first electric load connected to the busbar, and the MG
A second electric load connected to the set, a means for detecting the rotation speed or output frequency of the MG set, a means for comparing the rotation speed or output frequency with a set value, and the rotation speed or output frequency And a means for outputting an opening command to the third circuit breaker when the value is below a set value, a power supply control device for a bus having an MG set. 13. The busbar power supply control device having an MG set according to claim 10, wherein the second electric load is an ABWR internal pump.