JPS5843135A - Network power receiving facility - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to network power receiving equipment, and more particularly to network power receiving equipment that prevents a 10-tector circuit breaker from erroneously shutting off when regenerative power is generated from a regenerative power generating load such as an elevator or a motor. be.

Recently, highly reliable spot-net and talk power receiving equipment have been adopted as power receiving equipment for concentrated loads with high load density such as buildings. Figure 1 shows an example of the circuit of such network power receiving equipment.
1b and 1c are feeders connected to distribution lines drawn out from a substation (not shown), and 2" *
2 b+ 2. c is a high voltage side disconnector, 3a, 3b.

3C is a network transformer, 4a, 4b and 4c are protector current transformers connected to the low voltage side of network transformers 3a, 3b and 3c. 5alSbe5C is a network relay, 6a, 6b and 6C are current transformers for Hough of99
7a17b7C is protector breaker 8a/8b+8c
9 is a network bus bar, 10 is a load line breaker, 11 is a general load that does not generate regenerative power, 12 is an elevator, motor, etc. A regenerative power generation load 13 that generates regenerative power is a network bus voltage detection transformer. In the circuit example shown in FIG. 1, feeders 1a, Ib
, 1c have three lines, but a network circuit can be formed if there are two or more lines, and there are various numbers of lines.

When such network power receiving equipment is operating normally, the feeders 1a and 1b of each line.

Network transformers 3a, 3b, 3c connected to IC
The step-down power is supplied to the load. However,
For example, if an accident such as grounding or short circuit occurs on the high voltage side of feeder 1a, a distribution line breaker installed on the substation side of the distribution line (not shown) connected to feeder 1a will automatically shut off the line. Then, the protector breaker 8a provided in the feeder 1a operates to shut off the electricity to the feeder 1a, and the feeder 1a becomes voltageless. Therefore, in this case, the other feeders 1b, 1c are connected to the network transformer 3b, respectively.
The network transformer 3a will be reverse excited from the network bus 9 side through +3c, but the network relays 5a and 5b+5C both have the function of detecting the power direction, and if any of the network relays When the network relay detects a current in the opposite direction, the network relay outputs an output to cause the protector circuit breaker to perform a disconnection operation. Therefore, as mentioned above (if an accident occurs on the high voltage side of the feeder 1a and the network transformer 3a is reverse excited from the network bus 9 side), the protector breaker 8a will perform a breaking operation and the connection to the accident point will be interrupted. The flow of fault current is prevented.

Since the load such as the elevator motor that is generated is connected,
When an elevator ascends or descends at high speed, a large amount of electric power is regenerated from the elevator motor, especially when the elevator is decelerated. Therefore, when the power receiving equipment is under a light load, current flows in the opposite direction to )□Egu 1a, Ib, and Ic, and as a result, the network relays 5a, 5b, and 5C operate simultaneously, and the respective protector circuit breaker 8a, 8b, 8c
There is a possibility that the power supply to the network bus line 9 may be completely stopped. In order to prevent the protector circuit breaker from erroneously breaking off due to such regenerative power, conventional methods have been considered to temporarily or permanently connect a pseudo load that absorbs the regenerated power. This has the disadvantage of increasing unnecessary power loss. There is also a method of delaying the output of the network relay when a small power current such as regenerative power is generated in the opposite direction, so that the protector circuit breaker does not operate to cut off while the regenerative power continues.

In this case, even if it is clearly an accident and requires prompt maintenance for safety reasons, such as an accident that generates a small current in the opposite direction, the output of each network relay must be logically controlled. When all network relays simultaneously detect current in the opposite direction, such as when regenerated power is generated, there is a method to check the current in the circuit and prevent all of the protector circuit breaker from shutting off, but in this case, the regenerated power It is assumed that the feeders pass through each protector breaker approximately evenly, and if the impedance of each feeder is uneven, the current in the opposite direction of the regenerative power will be uneven, and the operating sensitivity of the network relay will not be satisfied. In addition, with this method, when regenerative power is being generated, it is possible to create feeders that are not energized for construction work, etc., and to reliably prevent the protector breaker from disconnecting. If the power is stopped at the substation side, the network relays installed on the feeders of other lines that have not been deenergized will issue a cutoff output, and the network relays of the feeders that have been de-energized will also be disconnected from the network. A cutoff output is generated by reverse excitation of the transformer. Therefore, in the end, the cutoff outputs of all the network relays were aligned at the same time, and the cutoff operation of the protector breaker was prevented, so that the energization was stopped. The feeder that is supposed to be in a power outage state cannot be maintained due to reverse excitation from the network transformer, and as a result, there is a problem in that the energization cannot be stopped until the regenerated power disappears.

This prevents the entire load from being cut off by preventing the cut-off operation of all protector circuit breakers, and also prevents power outages caused by accidents.

When a current in the opposite direction occurs, the protector breaker can be immediately cut off even if the current is small, and it also prevents erroneous cutoff caused by unequal amounts of reverse current flowing into each protector breaker. can also be prevented,
Furthermore, we have proposed a highly reliable network power receiving facility that can artificially and instantaneously stop the power supply to the feeder regardless of the generation of regenerative power.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The network power receiving equipment of the present invention will be explained in detail below with reference to drawings showing embodiments. 1. FIG. 2 is a circuit diagram of the network power receiving equipment according to the present invention.

In FIG. 2, 1aA1 (it feeder, 2a-2
C is a high voltage side disconnector, 3a to 3C is a network transformer whose high voltage side is connected to feeder 1i+~IC via high voltage side disconnector 2a~2 (4a to 4c is a network transformer connected to feeder ~11x)
The protector fuses 05a to 5c installed on the low voltage side of lc are network relays, 6a to 6c are prochikku'Yugetsu current transformers, and 7a to 7c are connected between both ends of 10 protector circuit breakers 8a to 8c. The transformed ridge CT and TCTC for detecting voltage between poles are wound around the annular core Ca A-C (with the same number of turns on each core. Two input windings w1
a~W and one W2a-W2c] Output winding w3=~
This is a current combining current transformer consisting of w3cc. 9 is a network bus bar to which the low voltage sides of the feeders 13 to 1c of each line are commonly connected, 1o is a load line breaker, 11 is a general load that does not generate regenerative power, and 1.2 is an elevator motor or a motor, etc. Regenerative power generation load that generates regenerative power, 1
3 is a secondary winding. 17a to 17C are provided corresponding to each protector breaker 83 to 8c, and open and close in conjunction with the breaking and closing operations of each protector breaker 83 to 8C. do. Normally closed 1mm contact and normally open auxiliary contact. These both ends are connected to protectors and disconnectors 8a to 8c in which the normally open auxiliary contacts 171 to 17C are provided via respective series circuits of each adjustment resistor 15 and each normally open auxiliary contact 17a to 17c. Controlled network relay 5a
～Current combining current transformer TcTa provided on the input side of 5C～
The input windings wla to w0 of TCTc. are connected to each of them. The impedance of each circuit including the incoming winding wire w1a4vlc can be adjusted by an adjustment resistor 15 to be equivalent to the impedance of the circuit of each feeder 1a to 1c. On the other hand, the secondary windings of the current transformers 63 to 6c for 10 techters are current combining current transformers TCT,
-, T'CTc0) is connected to the input winding W2 a-AV2 C. and current composite current transformer TCT, #TCr
The secondary windings of the inputs of , ' are all wound with the polarity shown by the mark . Therefore, the current combining current transformer TCT
~TCrc input windings Wla-w1c and w2a-w2o
The magnetic fluxes caused by the currents flowing through the two act on each other differentially, and the magnetic fluxes due to the difference of the currents generate output currents in the output windings w3a-w3c, and the output currents are transferred to the network relay 5a.
~5C is inputted.

Each of the network relays 53 to 5c checks the direction of the current passing through the protector circuit breakers 8a to 8c based on the current combination, and when the current flows from the network bus 9 side, that is, in the opposite direction, it immediately shuts off. It has a reverse power cutoff function that generates an output to cut off the protector, circuit breaker, and 8a to 8c. Additionally, it is equipped with a silent pressure closing function and an overvoltage closing function. The network power receiving equipment of the present invention is constituted by these devices.

The control operation of the network power receiving equipment configured as described above will be explained. Now, in the network power receiving equipment shown in Figure 'N2, the high voltage side disconnectors 2a to 2C and the load line breaker 10 are closed, and the regenerative power generating load 1
When the regenerative power is not generated from 2 and the operating state is normal, the output current of the normally open auxiliary current transformer 14 changes in conjunction with the closing operation of the protector breakers 8a to 8C. Each input winding W of each current composite current transformer TCTa-TCTc is
la-)%~',.

flows to On the other hand, the output current of the protector current transformers 6a to 6C is the input winding W2. M-%■Flows to ShuP. Therefore, the output windings W3a-w3c have the input winding Wla4.
■□.

An output current is generated for the magnetic flux due to the difference between the electric current flowing between and W and W, i□, -.
a ”) is input to C.-cloudy cloudy〒144i---←
Line spring bird? +9 In other words, the current flowing through each feeder 13 to 1c and the total current flowing through the general load 11 and regenerative power generating load 12 are divided proportionally by the number of lines of the feeder, and the current input is:
That is, the current flowing through the g feeders 1a to 1c is equivalent to the current flowing from the network bus 9 to the general load 11 and the regenerative power generation load 12.1. ) current components cancel each other out. Therefore, in such a state, the output windings W of each current combining current transformer TCTs to TCTc
From aa to Wac, each network relay 53 to . 5
No output current flows through c. Therefore, feeders 1a-1
cY is not present, therefore, the network relays 53 to 5c do not issue a cutoff signal, and the protector circuit breakers 83 to 8C all maintain a closed state. : Here, we will first explain the operation when no regenerative power is generated. If a grounding accident occurs on the A voltage side of the feeder to which the network transformer 3a is currently connected, a distribution line breaker installed on the substation side of the distribution line (not shown) connected to this feeder Ia The circuit operates as a cutoff, and the fault current flowing from the substation to the fault point is blocked. Therefore, a fault current is supplied in the opposite direction to the fault point from the healthy feeder 1b and the IC side through the network bus 9 and the network transformer 3a. Therefore, the protector current transformer 6a
An output current in the opposite direction flows to the input winding W2a of the current combining current transformer TO"l-a, and an output current in the opposite direction flows to the output winding Waa and is applied to the network relay 5a. It flows to the fault point. Since the fault current does not flow through the lines connecting the network bus 9, the general load 11, and the regenerative power generation load 12, its influence does not appear on the input winding W+a.

Therefore, the protector breaker 8a immediately performs the breaker operation, and at the same time, the normally open auxiliary contact 17a opens.

As a result, the feeder 1a having the fault point is also disconnected from the network bus 9 and becomes voltage-free.

In addition, at the time of the accident, other feeders 1b, 1cW2C
The current flowing through the other input winding Web and W+c increases, causing a difference between the current flowing through the other input winding W and the output winding W.

Since the output current flows from Wac to the network relays 5b, 5c, or this output current is in the forward direction, the network relays 5''b, 5c do not operate.

Then, since the normally open auxiliary contact 17a is opened, the secondary circuit of the regenerative power detection current transformer 14 becomes in a circuit state equivalent to the remaining two energized feeders 2b and 2C.

Next, a case will be described in which regenerative power is generated from the regenerative power generating load 12 when the network power receiving equipment is operating normally. When regenerative power is generated, the current detected in the secondary winding of the regenerative power detection current transformer 14 is transferred to the current combining current transformer TCTa of each feeder 1a/IC.
The currents are shunted to the input windings W+a to Wlc of TC"I'c, respectively, but the input windings W+ a -y W+ c and W2a w
It is wound differentially with W2C, and the input winding W2 a
Since the output current of the protector current transformers 6a to 6C is flowing through NW2c due to the current flowing through the feeder 1a to IC, the influence of the output current due to regenerative power cannot be seen in the output winding SS□a a to Wac. As a result, none of the network relays 5a to 5C output a cutoff signal. Therefore, even if regenerated power is generated, the protector circuit breakers 83 to 8C all perform the cutoff operation, and erroneous cutoff operations can be prevented.

On the other hand, when regenerative power is being generated, feeder la
If an accident such as grounding occurs on the high voltage side of the line, the fault current will be transferred to the feeder '1b of the other line.

Since it is supplied from the current combining current transformer TCTa~
A reverse current flows only in the input winding HVv2a of TCT c, and a reverse current flows in the output winding Waa of feeder 1a's current combining current transformer "l-C'ra". Output current corresponding to network relay 5a
The network relay 5a operates, and the protector breaker 8a immediately operates to cut off the fault current to prevent the fault current from flowing in the opposite direction to the fault point. Then, as the protector breaker 8a performs the breaking operation, its normally open auxiliary contact 17a opens, and the current combining current transformers TCTb and TCT of the other two energized feeders 1b and Ic are opened.
The input winding Wlb of c.

The output current of the regenerative power detection current transformer 14 is shunted only to Wsc. In this way, the output current of the regenerative power detection current transformer 14 is adjusted in relation to the breaking operation of the protector breaker.
By diverting the current to the feeders that are energized, it is possible to stabilize the operation of the network relays 5a to 5C. In addition, when all the protector circuit breakers 8a to 8C are open, all the normally closed auxiliary contacts 16a to 16C are closed and short-circuit the secondary winding of the regenerative power detection current transformer 14, so the regenerative power is Even if a private generator (not shown) connected to the generated load 12 is operated, there is no problem with the regenerative power detection current transformer 14.

3 and 4 show other embodiments of the network power receiving equipment according to the present invention, and the same components as those in FIGS. are doing.

In Figure 3, a general load 11 and a regenerative power generation load 1 are shown.
2 are separately connected to the network bus 9, and the line connecting the general load 11 to the network bus 9 is provided with a load current detection transformer 18. Separately from this, a negative +4+L flow combining current transformer 19 is provided, and its input windings W4a and W4b are the secondary windings of the load current detection current transformer 18 and the regenerative power detection current transformer 14. and both ends of the output winding W4C are normally closed auxiliary contacts 16a.
-16C are connected in series and both ends are connected by a pin.

Therefore, the sum of the detected currents flowing through the general load 11 and (b) the raw power generating load 12 is detected by the load current combining current transformer 19, that is, the total load current is adjusted by the adjustment resistor. The feeder 15, 15.
3~ Turtle flow synthesis transformer “l” CTa installed in IC
~TCTC(7) Each input winding W+ a ~W+ c
I am inputting 2. Therefore, the network power receiving equipment shown in FIG. 3 also operates in the same way as that shown in FIG. 2, and the same effects can be obtained.

In Figure 4, a general load 11 and a regenerative power generation load 1 are shown.
2 are separately connected to the network bus 9, and when regenerative power is generated (*12), a current transformer 14 for detecting regenerative power is provided only on the line connecting 12. In this case, the same effect as the network power receiving equipment shown in FIG. 2 can be obtained. However, the regenerative power generated from the regenerative power generation load 12 is The total current is detected by the regenerative power detection current transformer 14, and each current combining current transformer TCT
Since it is input to each input winding W+a to W+c of a to T"CTc, the network relays 53 to 5C operate sensitively; therefore, when regenerative power is generated, the network shown in FIGS. 2 and 3 Although the protector circuit breakers 83 to 8C tend to become inoperable for a slightly longer period of time than the power receiving equipment, there is no problem in practical use.

In this embodiment, there are three feeders 1a, lb, lc.
It goes without saying that the present invention can be implemented without being limited to the number of lines, and that two or more lines may be used. Furthermore, the current combining current transformer "l'cTa~1'C
For Tc, a semiconductor circuit limited to one using ring-shaped iron cores Ca to Cc can also be used. Normally open auxiliary contact 16a
~16CE The circuit provided with the normally open auxiliary contacts 17a to 17C can also be replaced with a semiconductor circuit.

Furthermore, the secondary winding and input winding W+ a --W+ of the current transformer 14 for regenerative power detection correspond to the impedance of each feeder 13 to 1c and each feeder 13 to IC.
If the impedances of the respective circuits connected to c are equal, it is not necessary to use the adjustment resistor 15.

As detailed above, the network reception equipment according to the present invention detects the short waves flowing through the feeder, the current including the current flowing through the regenerative power generating load, or the current flowing through the regenerative power generating load. , the current including the current flowing to the regenerative power generating load or the current flowing to the regenerative power generating load 1: A current flowing through the regenerative power generating load, through the auxiliary contact that operates in conjunction with each protector circuit breaker, to the current detected at each feeder. In addition to the differential input, the combined output current is input to the network relay, so the network relay provided at each feeder can control the protector breaker while minimizing the influence of regenerated power. Therefore, the protector circuit breaker immediately cuts off the fault current flowing in the reverse direction to the feeder, and also quickly cuts off the small fault current that occurs when regenerative power is being generated. do. In addition, even if the protector breaker is stopped due to unevenness in the amount of regenerated electric power for each feeder, the protector breaker can be instantly and reliably cut off, and the feeder can be placed in a power outage state. It has excellent advantages such as being able to maintain

[Brief explanation of the drawing]

Figure 1 is a circuit diagram of conventional network power receiving equipment:'1
1 FIG. 2 is a circuit diagram of the network power receiving equipment according to the present invention,
3 and 4 are circuit diagrams of network power receiving equipment showing other embodiments of the present invention.

Claims (1)

[Scope of Claims] In a network power receiving facility in which a protector breaker and a network relay are provided in each of the feeders of a plurality of lines, and the protector breaker is controlled by the operation of the net r>- relay, the same power is generated. A regenerative power detection current transformer and a protector current transformer are provided on the line to which the load is connected and the feeder of each of the lines, and the output of the regenerative power detection current transformer is connected to the protector breaker. The protector breaker is constructed by differentially adding the output of the protector current transformer of the feeder to which the protector breaker is connected via an auxiliary contact that interlocks with the opening/closing operation, and operating the network relay with the output of the difference. Network power receiving equipment that controls the network number.