JP3048016B2 - Construction bypass switch with trip device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a construction bypass switch with a trip device for switching from a construction bank to a sound bank.

[0002]

2. Description of the Related Art As shown in FIG. 3, when a transformer TrB of a bank B is exchanged, a low voltage side of a bank A and a low voltage side of the bank B are connected by a bypass switch 40 in the conventional method. After that, the power detection and phase detection are performed, and if normal, the low-voltage bypass switch 40 is turned on. Then, the primary cutout PC of the B bank is opened to exchange the transformer TrB of the B bank.

[0003]

However, the transformer TrA of the bank A is 50 kvA, the tap voltage of the transformer TrA is 200 V, while the transformer TrA of the bank B is
B is 20 kvA, and the tap voltage of this transformer TrB is 22 kVA.
If the voltage is 0 V, a loop current flows from the bank B to the load on the bank A when the bypass switch 40 is turned on. This is because the transformer TrB on the B bank side tends to have a large load as the load sharing because the tap voltage on the B bank side is higher than the tap voltage on the A bank side. However, in this case, since the capacity of the transformer TrB on the bank B side is small, the load current becomes an overload current, and the transformer TrB is burned out or the primary cutout PC
Fuse may be melted. For this reason,
There is a problem that bank switching cannot be performed reliably.

[0004] It is an object of the present invention to notify that an overload current has flowed when a bypass switch is turned on to enable bank switching and to open the bypass switch, thereby protecting the transformer and the primary cutout. It is another object of the present invention to provide a construction bypass switch with a trip device that prevents the bypass switch from being opened due to a malfunction.

[0005]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention provides a bypass bypass for construction with a trip device for connecting the low voltage sides of both banks by a connecting cable and switching one bank to the other bank. A drive unit for turning on and off the bypass switch; an overload current detection unit for detecting an overload current of the transformer in the one bank; and an overload current based on a detection signal of the overload current detection unit. Determination means for determining that the flow has flown, opening drive means for opening the bypass switch based on a command signal from the determination means, and measurement for measuring the closing time when the bypass switch is closed by the drive means Means,
When the determining unit determines that the overload current has not flown based on the detection signal of the overload current detecting unit within a predetermined measurement time of the measuring unit, invalidates the opening drive of the bypass switch by the opening driving unit. The gist of the present invention is to provide an invalidating means for performing the above.

[0006]

With the above arrangement, the bypass switch is turned on by the driving means, and one bank is switched to the other bank. Then, the overload current detecting means detects the load current flowing through the bank, and based on this detection signal, the determining means determines whether the current is the overload current. On the other hand, when the bypass switch is turned on by the driving means, the closing time is measured by the measuring means, and if the overload current is not determined by the determining means within a predetermined time, the bypassing by the open driving means is performed by the invalidating means. Disable the open drive of the container.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to the drawings. As shown in FIGS. 1 and 2, distribution lines U, V, and W are provided with banks A and B, respectively. The description of the A bank will be described below. In the configuration of the B bank, the same components will be denoted by the same reference numerals and description thereof will be omitted. Primary cutout PCU, PCV, PCW provided for each phase in the distribution lines U, V, W
Are connected via a pair of transformers Tr1 and Tr2. A load D is provided on the low voltage side of the transformers Tr1 and Tr2.

[0008] The transformers Tr1 and Tr2 are V-connected, and 3 from the low voltage side of the transformers Tr1 and Tr2.
Two output terminals P, C1 and C2 are provided. Further, a middle point between the output terminals C1 and C2 is grounded to form a ground terminal N.

Therefore, a line voltage of 100 V can be taken out from the output terminal C1 or the output terminal C2 and the ground terminal N, and can be supplied to the load D of a general household. Further, a line voltage of 200 V can be extracted from the output terminal P and the output terminal C1 or the output terminal C2, and can be supplied to a load D such as a factory.

A three-phase four-wire bypass switch 1 is connected to the low-voltage side of both banks A and B via connection cables LA, LB, LC and LN. A power detector / phase detector 3 is connected to the bypass switch 1 via a control line 2.

The bypass switch 1 includes a pair of fixed electrodes opposed to each other corresponding to each phase, and movable electrodes DU, DV, DW, DN for closing or opening the pair of fixed electrodes.
And a drive circuit 4 for driving the movable electrodes DU, DV, DW, DN. Thus, the drive circuit 4 can automatically open and close the bypass switch 1, and can also manually open and close the bypass switch 1.

Next, the configuration of the drive circuit 4 provided inside the bypass switch 1 will be described in detail. As shown in FIG. 2, MC2 is a second relay, which is energized by a control signal from the power detector / phase detector 3. The second relay MC2 is configured to open and close only the movable electrode DN, and to control the opening and closing of the second contact 5 of the a contact.

MC1 is a first relay, which is connected in series with the second contact 5. The first relay MC1 opens and closes the movable electrodes DU, DV, and DW, and contacts the first contact 6 of the a contact connected to the second relay MC2 and the a contact that drives the closing display circuit (LED) 7. The third contact 8 is controlled to open and close.

Reference numeral 9 denotes a metal outlet provided in the bypass switch 1, and one end of the control line 2 is connected to the metal outlet 9. L1 to L4, R1 to R
Reference numeral 4 denotes output lines connected to the output terminals P, C1, C2, and N of both banks, respectively, which are connected to a plurality of connection terminals t provided in the metal outlet 9, respectively.
The drive circuit 4 is also connected to the connection terminal t of the metal outlet 9.

Next, the configuration of the voltage detector / phase detector 3 will be described in detail. As shown in FIG. 3, reference numeral 10 denotes a metal outlet provided in the power detector / phase detector 3, to which the other end of the control line 2 is connected. Reference numeral 11 denotes a power detection / phase detection circuit, which is connected to a plurality of connection terminals t provided on the metal outlet 10.

Therefore, the voltages and phases from both the A and B banks are input via the output lines L1 to L4, R1 to R4 and the control line 2. Therefore, the power detection and phase detection circuit 11 performs power detection and phase detection, and
It is determined whether or not can be inserted.

Reference numeral 12 denotes a forced lock release switch provided in the power detection / phase detection circuit 11, which is configured to perform forced power transmission when there is no voltage on the load side. That is, the switch is used when used in the same manner as a conventional bypass switch. Reference numeral 13 denotes an LED provided in the power detection / phase detection circuit 11, which is turned on when the forcible lock release switch is turned on.

Reference numeral 15 denotes a power detection / phase detection display circuit provided in the power detection / phase detection circuit 11, which indicates whether the power detection / phase detection is normal. Reference numeral 16 denotes a buzzer connected to the voltage detection / phase detection display circuit 15, which informs, for example, an abnormality by sound. Reference numeral 14 denotes a test switch provided in the voltage detection / phase detection circuit 11 for checking whether the voltage detection / phase detection circuit 11 operates normally.

Reference numeral 17 denotes a power supply contact provided in the power detection / phase detection circuit 11, which is turned on under the control of the power detection / phase detection circuit 11 when the power detection / phase detection is normal. ing.

VSD1 and VSD2 are 100V or 20V
This is a voltage switch that switches the voltage to 0V. That is,
Since the voltage detection / phase detection circuit 11 and the carrier reception circuit 21 are for 100V, the voltage detection / phase detection circuit 11 and the carrier reception circuit 21 are switched to the power detection / phase detection circuit 11 and the carrier reception circuit 21 by the switching operation of the voltage switches VSD1 and VSD2.
0 V is not applied.

The voltage switch VSD1 is connected to power supply input lines D1 and D2 connected to a signal line connecting the connection terminal t and the power detection / phase detection circuit 11, and an output line L3 on the A bank side. , L4 supply power to the power detection and phase detection circuit 11. Reference numeral 20 denotes the voltage switch VSD1 and the
A power switch that supplies power to the phase detection circuit 11. Further, the voltage switch VSD2 is connected to signal input lines N1 and N2 connected to a signal line connecting the connection terminal t and the voltage detection / phase detection circuit 11. Therefore, the voltage switcher VSD2 transmits a command signal, which will be described later, from the output lines R3 and R4 on the B bank side via the control line 2 to the signal input lines N1 and N1.
It flows through N2. The voltage switch VSD2 also supplies power to the carrier receiving circuit 21.

Reference numeral 21 denotes a carrier receiving circuit connected to the voltage switch VSD2, which receives a command signal from an overload detector 22, which will be described later, via the signal input lines N1 and N2. . Reference numeral 23 denotes a drive contact provided in the carrier receiving circuit 21, and the drive switch 23 includes the voltage switch VSD2.
It is turned on when power is supplied from the. When the command signal from the overload detector 22 is received by the carrier receiving circuit 21, the driving contact 23 is turned off by the carrier receiving circuit 21.

Reference numeral 24 denotes the drive contact 23, the power supply contact 1
7 and connected in series so that the drive circuit 4 of the bypass switch 1 can be driven by the switch 24 so that the switch 1 can be closed. Has become.

Reference numeral 25 denotes an open switch of a contact b connected to the drive contact 23. By opening the open switch 25, the bypass switch 1 can be manually opened.

Reference numeral 33 denotes a timer relay, which turns on the closing switch 24 to operate the drive circuit 4 and drives the bypass switch 1 at the same time as being turned on to measure the time. That is, the closing time of the bypass switch 1 is measured. 34 is the carrier receiving circuit 2
This is an a-contact invalidating contact connected in parallel to one drive contact 23, and is turned on / off under the control of the timer relay 33. That is, the invalidating contact 34 is turned on after a predetermined time (5 minutes in this embodiment) from the start of the time measurement by the timer relay 33 being driven.

When the invalidating contact 34 is turned on, this operation is detected by the carrier receiving circuit 21, and this operation signal is sent to the signal input lines N1, N2, the output lines R3, R4, and the connection cable L.
The carrier is transmitted to the carrier transmitting circuit 26 via C and LN and the signal injectors 30a and 30b.

Next, the configuration of the overload detector 22 will be described in detail. As shown in FIG. 4, 26 is an overload detector 2
2 is a carrier transmitting circuit as a transmitting means provided inside, and is configured to carry a command signal to a carrier receiving circuit 21 of the power detector / phase detector 3. CT1 and CT2 are current transformers as overload current detecting means attached to the connection cables LA and LC of the B bank, and are connected from the transformers Tr1 and Tr2 of the B bank to the load D side of the A bank. ,
An overload current is detected from flowing from the transformers Tr1 and Tr2 on the A bank side to the load D side on the B bank. The current transformers CT1 and CT2 are connected to the carrier transmission circuit 2
6 respectively.

27a and 27b are the current transformers CT1 and CT
2 is a comparison circuit connected to each. The comparison circuits 27a and 27b compare the detection signals from the current transformers CT1 and CT2 with a preset threshold value. That is, when the current transformers CT1 and CT2 detect an overload current, the comparison circuits 27a and 27b output an output signal.

An OR circuit 28 is connected to the comparison circuits 27a and 27b.
The output signal from is input. 29 is a transport drive circuit connected to the OR circuit 28,
A command signal of a predetermined frequency (50 kHz in this embodiment) is generated.

30a, 30b are connection cables LC, LN
A signal injector connected to the carrier driving circuit 2
9 is injected into the connection cables LC and LN,
Bypass switch 1, control line 2, and signal input lines N1, N
The command signal is transmitted to the carrier receiving circuit 21 of the power detector / phase detector 3 through the second signal generator 2. The signal injector 30
Power is supplied to the overload detector 22 from the connection cables LC and LN by a and 30b.

Reference numeral 31 denotes an a-contact, which is turned on when the carrier transmission circuit 26 is driven and turned off when an overload current flows.

Reference numeral 35 denotes a completion indicator (for example, an LED) connected to the carrier transmitting circuit 26, which is turned on (lights up) based on an ON operation signal of the invalidation contact 34 carried from the carrier receiving circuit 21. It is supposed to.

Reference numeral 32 denotes a code reel,
The drive contact 23 of the carrier receiving circuit 21 in the phase detector 3 and the drive contact 31 of the overload detector 22 are connected in parallel. Therefore, when the drive contact 23 of the carrier reception circuit 21 is not opened or closed by the command signal of the carrier transmission circuit 26, the bypass switch 1 can be opened and closed by turning on and off the drive contact 31 in the carrier transmission circuit 26. I have.

The operation of the work bypass switch with a trip device configured as described above will be described. First, B
When replacing the transformers Tr1 and Tr2 of the bank (construction bank), the bypass switches 1 in the open state are connected to the low voltage sides of the A bank (healthy bank) and the B bank by connecting cables LA, LB, LC, and LN. Connect through. And
The control line 2 is connected to the metal sockets 9 and 10 of the bypass switch 1 and the voltage detector / phase detector 3.

The current transformers CT1 and CT2 are attached to the low-voltage side of the bank B or the connection cables LA and LB, respectively.
The signal injectors 30a and 30b are attached to C and LN, respectively.

On the other hand, the control line 2 is controlled by the output lines L1 to L4 and R1 to R4 connected to each phase in the bypass switch 1.
The voltage value and the phase angle of each phase are input to the power detection / phase detection circuit 11 of the power detection / phase detection device 3 via. In addition, power switch VSD
2 is supplied to the carrier receiving circuit 21. After confirming that transmission / reception is possible between the carrier transmission circuit 26 and the carrier reception circuit 21, the drive contact 23 in the carrier reception circuit 21 is turned on and the drive contact 31 in the carrier transmission circuit 26 is turned on. Thereby, a connection error between 30a and 30b can be found.

When the power switch 20 is turned on,
The power detection / phase detection circuit 11 performs the power detection / phase detection of the banks A and B, determines whether the bank can be switched, displays the result on the power detection / phase detection display circuit 15, and when the bank can be switched, The power supply contact 17 is turned on.

When the closing switch 24 is turned on in this state, the second contact MC2 of the drive circuit 4 is excited because the drive contact 23 and the power supply contact 17 are on. The movable electrode DN is turned on by the excitation of the second relay MC2, and the second contact 5 is turned on. Then, when the second contact 5 is turned on, the first relay MC1 is excited, the movable electrodes DU, DV, DW are turned on, and the first contact 6 and the third contact 8 are turned on. As a result, the closing display circuit 7 is driven to indicate that the bypass switch 1 has been closed.

On the other hand, when the second relay MC2 is excited, the timer relay 33 is driven to measure the time.
After the timer relay 33 measures for 5 minutes, the invalidation contact 34 is turned on. Then, the carrier receiving circuit 21 detects that the invalidation contact 34 has been driven, and sends this operation signal via the signal input lines N1 and N2, the output lines R3 and R4, the connection cables LC and LN, and the signal injectors 30a and 30b. To the carrier transmission circuit 26.

The carrier transmission circuit 26 drives (turns on) a completion indicator (LED) indicating that the invalidation is completed based on the operation signal. The operator confirms that the completion indicator has been driven, and confirms that the primary cutout PC in bank B
U, PCV and PCW are opened in order, and the transformers Tr1 and T
Replace r2. Thereafter, the primary cutout PCU, PCV, and PCW are sequentially input again.

Next, to open the bypass switch 1, the open switch 25 is turned off. Thereby, the first relay M
Since C1 is demagnetized, the movable electrodes DU, DV, DW are opened, the first contact 6 and the third contact 8 are turned off, the closing display circuit 7 cancels the closing display, and the second relay MC
2 is demagnetized, so that the movable electrode DN is opened. As a result, since the opening of the bypass switch 1 is completed, the bank construction is completed by removing the connection cables LA, LB, LC, and LN of the banks A and B, respectively.

Therefore, since the invalidating contact is in the ON state, the noise enters the carrier receiving circuit 21 and the bypass switch 1 does not open even if the carrier receiving circuit 21 malfunctions and the driving contact 23 is turned off. Absent. As a result, malfunction of the bypass switch 1 due to noise can be prevented.

After the bypass switch 1 is turned on, the timer relay 33 activates the drive contact 23 for a predetermined time,
If the overload current does not flow within that time, it is determined that the overload current does not flow, and during operation, opening of the bypass switch 1 is prevented, and power is supplied to the load D of the B bank. it can.

Further, even when the bypass switch 1 is turned on and the transfer is impossible due to a change in the load D, the drive contact 23 is turned off to trip the switch. Thus, when an overload current flows through the B banks Tr1 and Tr2 when the bypass switch is turned on, the command signal cannot be transferred to the transfer receiving circuit 21, thereby preventing the bypass switch 1 from being unable to be opened.

Now, even when the bypass switch 1 is turned on in a state where the tap voltages of both banks are different,
When the bypass switch 1 is turned on, the timer relay 33 starts measuring time. If an overload current flows through at least one of the connection cables LA and LC on the bank B side within 5 minutes, the current transformers CT1 and CT2 detect the overload current.

Comparison circuits 27a, 2 in carrier transmission circuit 26
7b compares the detection signals of the current transformers CT1 and CT2 with a predetermined threshold value (for example, 150% of the rated current), and when the load current exceeds this threshold value, judges that an overload current has flown and outputs The signal “1” is output to the OR circuit 28. When the output signal “1” is input from one of the comparison circuits 27 a and 27 b to the OR circuit 28, the OR circuit 28 outputs a driving signal to the transport driving circuit 29 and turns off the driving contact 31. To

The carrier drive circuit 29 injects a 50 kHz command signal into the connection cables LC and LN by the signal injectors 30a and 30b based on the drive signal. Then, this command signal is transmitted to the connection cables LC, LN and the output lines R3, R
4, received by the carrier receiving circuit 21 via the control line 2, the signal input lines N1 and N2, and the power switch VSD2.

The carrier receiving circuit 21 turns off the drive contact 23 based on the command signal. At this time, the invalidation contact 3
4, the first relay MC1 and the second relay MC2 are demagnetized, respectively, and the movable electrodes DU, D
V, DW, and DN open. In addition, the first to third contacts 5,
Since the switches 6 and 8 are turned off, the closing display circuit 7 cancels the closing display.

As a result, the transformers Tr1 and T
Since the overload current does not continue to flow through r2, the transformer Tr
1, Tr2 burnout, primary cutout PCU,
Fusing of PCV and PCW can be prevented. Therefore, the bypass switch 1 is turned on particularly when the tap voltages are different, and the bypass switch 1 is immediately opened when an overload current flows. Out PCU, PCV, PCW can be protected.

Further, since the overload detector 22 determines whether bank switching is possible or not, it is not necessary to check with a ledger and measure the tap voltage unlike the related art, and bank construction can be performed quickly.

In addition to opening the bypass switch 1 by the transport transmission circuit 26 and the transport reception circuit 21, the code reel 32 is connected in parallel with the drive contact 31 of the transport transmission circuit 26 and the drive contact 23 of the transport reception circuit 21. It is also possible to use it. In this case, the bypass switch 1 can be opened by turning off the drive contact 31.

It should be noted that the present invention is not limited to the above-described embodiment, and can be arbitrarily changed without departing from the spirit of the present invention.

[0053]

As described above in detail, according to the present invention, when an overload current is detected when the bypass switch is closed, the bypass switch can be opened. This has the effect of preventing burning of the transformer and blowing of the primary cutout fuse, and of preventing the bypass switch from malfunctioning and opening due to intrusion of noise or the like.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing configurations of a bypass switch, a voltage detector / phase detector, and an overload detector according to the present invention.

FIG. 2 is an electric circuit diagram showing a configuration of a drive circuit 4 provided inside the bypass switch 1;

FIG. 3 is an electric circuit diagram showing an internal configuration of a power detector / phase detector.

FIG. 4 is an electric circuit diagram showing an internal configuration of an overload detector.

FIG. 5 is an explanatory diagram showing a state in which a bypass switch is mounted on the low voltage side of both A and B banks.

FIG. 6 is an explanatory diagram showing a conventional example.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Bypass switch, 4 ... Drive circuit as drive means,
23: drive contacts as opening drive means, 27a, 27b
... comparison circuit as discriminating means, 33 ... timer relay as measuring means, 34 ... invalidating contacts as invalidating means, A, B ... banks, LA, LB, LC, LN ... connecting cables, CT1, CT2 ... Current transformer as load current detection means.

Continuing from the front page (72) Inventor Hiroshi Watanabe 1st character small needle in Inuyama-shi, Aichi Energy Support Co., Ltd. (56) References JP-A-2-32720 (JP, A) JP-A-4-12626 (JP, A) JP-A-3-49531 (JP, A) JP-A-2-87934 (JP, A) JP-A-63-24936 (JP, A) JP-A-3-49526 (JP, A) JP-A-3,495 −49529 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01H 33/59 H01H 9/54 H02J 3/04 H01H 85/00

Claims (1)

(57) [Claims] 1. A bypass switch for construction with a trip device for connecting a low voltage side of both banks by a connection cable and switching one bank to the other bank, a driving means for turning on and off the bypass switch. Overload current detecting means for detecting an overload current of a transformer in the bank of the bank, determining means for determining that an overload current has flowed based on a detection signal of the overload current detecting means, and a command signal from the determining means. Opening drive means for opening the bypass switch based on, at the time the bypass switch is turned on by the drive means,
A measuring means for measuring a closing time; and if the determining means determines that no overload current has flowed based on a detection signal of the overload current detecting means within a predetermined measuring time of the measuring means, the opening drive means A bypass switch for construction with a trip device, comprising: invalidating means for invalidating the opening drive of the bypass switch.