JP2002357143A - Automatic switching device for power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To switch from commercial power supply to an engine power generator having an automatic idle function after performing sufficient warming-up when power failure occurs. SOLUTION: When power failure of the commercial power supply 2 is detected by a power failure detection part 10, the engine power generator 3 is started and warmed up for the time set in a warming-up timer 13. A revolution speed detection part 14 detects revolution speed Ne of the engine power generator 3. The detected revolution speed Ne of the engine power generator 3 is inputted into a comparison part 15 and is compared with reference revolution speed, Neref to judge whether low idling is performed or not. When it is judged that low ilding is performed based on the revolution speed Ne, a relay 9 is turned on, and a pseudo-resistance 8 is connected with the engine power generator 3. The engine power generator 3 follows its own automatic idle function and detects that a load is connected to release low idling and switch to high idling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic power supply switching device, and more particularly to a power supply system in which, when one power supply system fails, an engine generator as another system is activated to supply power to a load. The present invention relates to an automatic power supply switching device.

[0002]

2. Description of the Related Art When a power system such as a commercial power supply fails to supply power to a load due to a power failure, an emergency switch is switched from the commercial power supply to the engine generator to supply the output power of the engine generator to the load. A known power supply switching device is disclosed in Japanese Patent Application Laid-Open No. 5-64382. In this type of power supply switching device, the engine generator is started immediately after a power failure, and after the voltage of the generator is established, that is, after the warm-up operation, power supply to the load is started. Note that a battery for supplying power to the load may be provided after the power failure occurs and before the power supply from the engine generator is started.

[0003]

As the engine generator used in the above-described power supply switching device, a generator having high versatility, that is, a generator which is normally operated alone is often used. Also, many engine generators are known to be equipped with an auto-idle device that reduces the number of revolutions in a no-load state from the viewpoint of energy saving and a decrease in operating volume (Japanese Utility Model Publication No. 2-40286). .

When an engine generator having such an auto-idle device is attached to the power supply switching device,
Since the warm-up operation is performed with no load, the warm-up operation is performed at a low rotation speed. Therefore, the warm-up time becomes long, and the supply of power to the load cannot be started in a short time. Further, in a system in which the warm-up time is determined in advance, power supply to the load is started before sufficient warm-up is performed.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems, and to supply power to a load after sufficiently warming up a short time after a power failure even in an engine generator having an automatic idle device. An object of the present invention is to provide a power supply automatic switching device as described above.

[0006]

SUMMARY OF THE INVENTION The present invention relates to an automatic power supply switching device for automatically switching connection to a load from a power supply system to an output side of an engine generator when a power supply system fails. A power switch for selectively connecting an output side of a generator to the load, and starting the engine generator at the time of a power outage of the power system, and moving the power switch to an output side of the engine generator after a scheduled warm-up operation. Switching control means for switching the power switch to the power system side when the power is restored, and when the engine generator rotation speed during the warm-up operation is lower than a predetermined rotation speed, the engine generator rotation speed There is a first feature in that a means for performing a warm-up operation by increasing the temperature is provided.

According to the first feature, at the time of a power failure, the engine generator is started, and after the warm-up operation is completed, the output side of the engine generator is connected to the load instead of the power supply system. When the engine speed during the warm-up operation is low, the engine speed can be increased, so that sufficient warm-up can be performed in a short-time warm-up operation.

[0008] Further, according to the present invention, the engine generator includes:
In a no-load operation state, the engine generator includes a rotation speed control unit that limits the engine generator rotation speed to a low idle rotation speed, and the engine generator rotation speed during the warm-up operation is limited to the low idle rotation speed. The second feature is that a dummy load is connected to the output side of the engine generator when the engine generator is present.

According to the second feature, when it is detected that the engine generator speed is limited to the low idle speed, the pseudo load is connected, and as a result, the limit to the low idle speed is established. Is released.

The present invention has a third feature in that the connection means is configured to intermittently connect the pseudo load. According to the third feature, power supply to the pseudo load is not performed continuously, so that heat generation of the pseudo load can be suppressed. Therefore, for example, a resistance load having a small wattage can be used as the dummy load.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 2 is a configuration diagram of a system including an automatic power supply switching device according to an embodiment of the present invention. In the figure, the automatic switching device 1 has a switching unit 11 for selectively supplying output power of a commercial power supply 2 and an engine generator 3 to an electric load 4. The switching unit 11 includes a contact 111 and a contact 11
And a solenoid 112 for switching the "1". The operation of the switching unit 11 is controlled by the control unit 12. It is assumed that the engine generator 3 is provided with a switch 31 that can select an auto-idle function that is operated at a predetermined low rotation speed at no load in order to prevent noise and improve fuel efficiency. If the switch 31 has been switched to the auto-idle “on” side, for example, when the magnetism corresponding to the magnitude of the load current is equal to or less than a predetermined value, the idle (low idle) operation is performed at a low rotation speed. If the load current is more than a certain level (for example, 1 A), the low idle operation is canceled and the operation is switched to the high idle operation with a high rotation speed. Switching from low idle to high idle is automatically performed by detecting magnetism corresponding to the load, and can also be performed by turning off the switch 31.

FIG. 3 is a block diagram of a control system including the automatic switching device 1. The control unit 12 is provided, for example, in a housing box that houses the automatic switching device 1 and is attached to a wall of a house or the like, and includes a board on which a microcomputer and the like are mounted. The control unit 12 includes:
A set time change instruction signal based on the operation of the set time change operation unit 5 and a control mode signal according to the selection of the control mode setting switch 6 are input. The control unit 12 has a function of constantly monitoring a power failure and a power recovery of the commercial power supply 2, and based on the monitoring result, the set time change instruction signal and the control mode signal, the switching unit 1
It controls the energization and de-energization of one solenoid 11a, the start and stop of the engine generator 3, the display on the display unit 7 composed of a liquid crystal display and the like.

Further, the control unit 12 is provided with a relay 9 for selectively connecting a load resistance (about several watts) 8 as a pseudo load to the engine generator 3.

The set time change operation unit 5 includes an operation switch 5
In response to the set time change instruction signal by operating the operation switch 51, the control unit 12 causes the control unit 12 to set a plurality of types (for example, 15 seconds, 3 seconds).
(0 second, 120 seconds) is selected and set as the warm-up time of the engine generator 3.

The control mode setting switch 6 has an operation dial 61 which can be rotated.
In order to set a control mode by the control unit 12 in accordance with the rotation of the control unit 12 between the first position P1 to the fourth position P4, different signals are input to the control unit 12 at each of the positions P1 to P4. .

The first position P1 is a position for stopping control by the control unit 12. The second position is an automatic switching control mode of the power system. By rotating the operation dial 61 to the second position P2, the switching control of the switching unit 11 by the control unit 12 and the switching of the engine generator 3 are performed. Start and stop control and display control of the display unit 7 are automatically executed.

In the third position P3, the engine generator 3 is manually started. Operation dial 61
When the rotation operation is performed to the position P3, the engine generator 3 is started. Further, in the fourth position P4, the output power of the engine generator 3 is supplied to the electric load 4. When the operation dial 61 is turned to the fourth position P4, the engine generator 3 is turned on regardless of the power failure of the commercial power supply 2.
The switching unit 11 is controlled so as to supply the output power to the electric load 4.

The operation in the automatic switching control mode (second position P2) will be described with reference to the flowchart of FIG. In FIG. 4, in step S1, it is determined whether or not a power failure has occurred in the commercial power supply 2. At the time of a power failure, it is determined in step S2 whether or not the flag FA is "0". The flag FA indicates whether the engine generator 3 is operating or not. When the engine generator 3 is operating, the flag FA is "1".

When it is determined that the flag FA is "0", that is, when the engine generator 3 is in the non-operation state, the process proceeds to step S3, and the set time by the instruction signal of the set time change operation unit 5, that is, the warm-up time, is set. The machine operation time is read. In step S4, the engine generator 3 is started, and the display on the display unit 7 is switched to the warm-up time display. As the warm-up time, the remaining warm-up time at the present time is preferably displayed.

That is, the control unit 12 displays the accumulated operation time of the engine generator 3 and the set time set by the set time change operation unit 5 during the warm-up operation after the engine generator 19 is started. The display content of the display unit 7 can be switched and controlled in a state where the decrease in the count is displayed in a countdown manner.

In step S5, it is determined whether the engine generator 3 is in the low idling operation or the high idling operation, based on whether the flag FC is "1" or "0". This flag is set in another routine (not shown), and is "1" for low idle and "0" for high idle.
Is set. For example, means for detecting the output frequency of the engine generator is provided, and the rotation speed Ne of the engine generator 3 is calculated based on the output. The flag FC is set to "1" if the rotation speed Ne is within the low idle range, while the flag FC is set to "0" if the rotation speed Ne is equal to or higher than the low idle range.

If the flag FC is "1", it is determined that the engine is in a low idle state, and the process proceeds to step S6, where the relay 9 is turned on and the load resistor 8 is connected. The connection of the load resistor 8 cancels the auto idle function,
The engine generator 3 is switched to high idle, and its rotation speed Ne increases. The connection state of the relay 9 is preferably performed intermittently at predetermined intervals, rather than being maintained while the flag FC is “1”. Since the load resistor 8 is intermittently connected, heat generation of the load resistor 8 can be suppressed, so that the power consumption of the load resistor 8 can be reduced.

If the idle state is established by the connection of the load resistor 8, the flag FC becomes "0", so that the step S5 becomes negative and the process proceeds to a step S7. Step S
At 7, the flag FA is set to "1" to indicate that the engine generator 3 is operating.

In step S8, the set time change operation unit 5
Execute the countdown of the counter that measures the set time set in. In step S9, the set time is reduced,
That is, the elapse of the warm-up time is displayed as a countdown.

In step S10, it is determined whether or not the set warm-up time has elapsed. When it is determined that the warm-up time has elapsed, the process proceeds to step S11, and the switching unit 1 switches the power supplied to the electric load 4 from the power system of the commercial power supply 2 to the output of the engine generator 3.
1, the display on the display unit 7 is switched to a state in which the accumulated operation time of the engine generator 3 is displayed. Step S12
Sets the flag FB to "1" to indicate that the output of the engine generator 3 is connected to the electric load 4. In addition,
When the electric power system of the commercial power supply 2 is connected to the electric load 4, the flag FB is set to “0”.

When the engine generator 3 is operating, the flag FA is set to "1" in step S7.
Step S2 is negative, and the process proceeds to step S13. In step S13, it is determined whether or not the flag FB is "0". If the flag FB is "0", the process proceeds to step S8 to continue the warm-up operation. On the other hand, if the flag FB has been switched to "1" in step S12 after the warm-up operation time has elapsed, step S13 is negative, and the warm-up operation process, that is, step S8 to step S12 is through.

When it is determined in step S1 that no power failure has occurred, that is, when it is determined that the power system of the commercial power supply 2 has been restored while using the output power of the engine generator 3, , Steps S1 to S14
The program proceeds to step S11, where it is determined whether or not the flag FB is "1".

When it is determined in step S14 that the flag FB is "1", the flow proceeds to step S15, where the electric load 4
The switching unit 1 switches the power supplied to the power supply from the output of the engine generator 3 to the power of the commercial power supply 2.
Control 1 At the same time, the engine generator 3 is stopped. In step S16, the counter for counting down the set time (warm-up time) is reset. In step S17, the flag FA and the flag FB are set to "0".

Next, the main functions of the control unit 12 will be described. In FIG. 1, the engine generator 3 has an auto-idle function. When the auto-idle is selected, depending on the presence or absence of a load, idling at a low rotation speed is performed when there is no load. Things. The power failure detection unit 10 monitors whether or not the output voltage of the commercial power supply 2 maintains a predetermined voltage to detect the presence or absence of a power failure. When a power failure is detected by the power failure detection unit 10, the engine generator 3
Is started and the warm-up timer 13 starts counting down. The set time of the warm-up timer 13 can be selected from a plurality of types.

When the engine generator 3 is started, the rotation speed detector 14 is energized, and the rotation speed Ne of the engine generator 3 is detected based on the output frequency of the engine generator 3. Note that the rotation speed Ne is not limited to the frequency, and can be detected based on an ignition pulse of an engine that drives the engine generator 3.

The detected rotational speed Ne of the engine generator 3
Is input to the comparison unit 15 and is compared with a reference rotation speed Neref for determining whether or not the engine is at low idle. Rotation speed Ne
Is lower than the reference rotation speed Neref, and it is determined that the engine is in a low idle state, the relay 9 is turned on. When the relay 9 is turned on, the engine generator 3 is connected to the load resistor 8 having a small wattage. The engine generator 3 detects that the load resistor 8 is connected, releases the low idle, and switches to an idle operation (high idle) at a preset high engine speed.

When the engine generator 3 is started and the countdown of the warm-up timer 13 is completed, the switching unit 11 is switched, and the output of the engine generator 3 is connected to the electric load 4 instead of the electric power of the commercial power supply 2. When the power is restored, the switching unit 11 is switched so that the electric power of the commercial power supply 2 can be supplied to the electric load.

[0033]

As is apparent from the above description, according to the first to third aspects of the present invention, during the warm-up operation period,
After sufficient warming up, the output of the engine generator can be connected to the load. In particular, according to the second aspect of the present invention, even when the engine generator having an auto idle function for performing idle operation at low rotation is used and the idle generator is operated at low rotation, the pseudo load is connected. As a result, the automatic idle state is automatically released. Therefore, even when the engine generator having such an auto idle function is used,
The power supply to the load can be started after the warm-up operation is sufficiently performed.

According to the third aspect of the present invention, since the heat generation of the pseudo load can be suppressed, a pseudo load having a small wattage can be used.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of a main part of an automatic power supply switching device according to an embodiment of the present invention.

FIG. 2 is a block diagram showing a configuration of a power supply system including an automatic power supply switching device according to an embodiment of the present invention.

FIG. 3 is a block diagram showing a hardware configuration of a control system of the automatic power supply switching device.

FIG. 4 is a flowchart showing a main part process of the automatic power supply switching device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Automatic switching device, 2 ... Commercial power supply, 3 ... Engine generator, 4 ... Electric load, 5 ... Setting time change operation part,
6 control mode setting switch 7 display unit 8 load resistance 9 relay 10 power failure detection unit 11
Switching unit, 12 ... Control unit, 13
... warm-up timer, 14 ... rotation speed detector, 15 ... comparator

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hiroyuki Eguchi 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (Reference) 3G093 AA18 BA00 BA21 BA22 CA01 CA03 CA04 CA05 CB14 DA01 DA12 DB23 DB28 EA03 EB09 EC01 FA07

Claims (3)

[Claims] 1. An automatic power supply switching device that automatically switches connection to a load from the power supply system to an output side of an engine generator when a power supply system fails, wherein the power supply system and the output side of the engine generator are selected. A power switch connected to the load, and starting the engine generator at the time of power failure of the power system,
Switching control means for switching the power switch to the output side of the engine generator after the warming-up operation, and for switching back the power switch to the power supply system side when power is restored, Means for performing a warm-up operation by increasing the engine / generator rotation speed when the rotation speed is lower than a predetermined rotation speed. 2. The engine generator according to claim 1, further comprising: a rotation speed control unit configured to limit the rotation speed of the engine generator to a low idle rotation speed in a no-load operation state. The engine generator according to claim 1, wherein the engine generator is configured to increase the engine generator speed by connecting a pseudo load to an output side of the engine generator when the engine speed is lower than a predetermined engine speed. Automatic power switching device. 3. The automatic power supply switching device according to claim 2, wherein the connection unit is configured to connect the pseudo load intermittently.