JP3328365B2 - Islanding detection 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 CGS for cogeneration (CGS) interconnection with reverse power flow to a ring system.
The present invention relates to an islanding detection device that detects that a customer has been disconnected from an electric power system and has become an independent system.

[0002]

2. Description of the Related Art FIG. 5 shows a protection relay defined in a guideline for cogeneration interconnection with reverse power flow to a ring system.

[0003] In FIG. 5, B _USB is the generating line of the CGS customer B to line Z _2, Z ₃ ring line system is connected via a breaker CB of B _01, B _02, T _r is the bus B _USB Terminal B _O3
Consumers receiving transformer via a breaker CB of being connected, SL is consumer distribution line that is interconnection through the circuit breaker CB ₁ to the secondary side of the transformer T _r, AG is the distribution line BL Circuit breaker CB
AC generator in the connected CGS through _2, L _1,
L ₂ is the premises load connected via a breaker CB _3, CB ₄ to the power distribution line SL.

Reference numeral 1 denotes a digital loop to which current signals from each of the current transformers CT for detecting the currents of B _O1 , B _O2 and B _O3 and a voltage signal from a voltage transformer (not shown) and a voltage signal from a voltage transformer (not shown) are input. The protection relay is composed of protection relays PWR ₁ and PWR ₂ on the lines Z ₂ and Z ₃ and a protection relay BPR on the bus B _USB .

[0005] 2 is a voltage transformer P connected to the bus B _USB
There is a reverse power flow when a voltage signal from T is input. This is a protection relay that is required at the time of CGS reverse flow. ing.

[0006]

SUMMARY OF THE INVENTION Therefore, the protection relay 2
Operates during CGS single operation to trip the circuit breaker B _O3 CB and cut off the interconnection. As a case where the CGS is operated alone, the cases shown in FIGS. 6 to 9 can be considered.

FIGS. 6 and 7 show a case in which a circuit breaker in a loop system is opened to become a single system. FIGS. 6 (a) and 6 (b) show a CBF.
7A and 7B show the operation of the protection relay when the loop is open and the operation of the back-up protection relay when the loop is open and when the terminal failure occurs.

FIG. 8 shows a case where a circuit breaker other than the loop system is opened and becomes a single system.
FIG. 9B shows a case in which the interruption of the other power transmission has failed, and FIG. 9 shows a case in which the system becomes a single system due to artificial erroneous opening.

[0009] In the CGS guidelines, the detection performance of the protection relay is defined as shown in FIG. FIG.
0, when the system power is balanced in the absence of an accident in the system, both the frequency detection method and the accident system detection method
Although the detection performance of the protection relay cannot be detected, CG
Most of the isolated operation states, for example, FIGS. 6 (a), (b), 7 (b), 8 (a), (b) can be detected by the relay specified in the S guideline. . However, when there is no accident in the single system and the power is balanced, for example, there is a drawback that the detection performance of FIGS. 7A and 9 is low.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has as its object to operate the main protection relay while the loop is being opened, or to be used alone in the case where the relay is erroneously opened due to an erroneous opening. An object of the present invention is to provide an islanding operation detection device capable of reliably detecting the islanding operation of a cogeneration customer with high sensitivity even in the case of power balance.

[0011]

Means for Solving the Problems To achieve the above object, an islanding operation detecting apparatus according to the present invention is an islanding operation detecting apparatus for a power generator in a cogeneration interconnection system having a reverse power flow to a ring system. A first and second optical transmission line for a protection relay for protecting first and second routes provided between a first and second bus of a power substation and a bus of a cogeneration customer; The optical transmission line is branched and connected to the terminal, and the first and second power supply terminals sent from the optical transmission line to the cogeneration customer terminal and the cogeneration system are connected.
Circuit breakers at customer terminals and disconnections on both sides of these circuit breakers
Pallet information of the device and two circuit breakers of each customer terminal
A single-system or second-system independent operation processing unit for inputting pallet information of each disconnector on both sides of the two circuit breakers is provided, and the isolated operation processing unit includes a circuit breaker of a power supply terminal unit of the first route.
If the pallet information of “OFF” or the disconnectors on both sides of
At least one of "pallet" pallet information or customer terminal
Pallet information of the two circuit breakers “OFF” or the two circuit breakers
If the disconnectors on both sides of the disconnector have at least one
Information, or circuit breaker of cogeneration customer terminal
If the pallet information of “OFF” or the disconnectors on both sides of
Output pallet information of "OFF" at least one by OR
A first OR circuit, and a power supply terminal of the second route
Pallet information of the circuit breaker “OFF” or disconnection of both sides of this circuit breaker
If the pallet information is at least one of
Pallet information of the two circuit breakers "OFF" at the key house terminal or this
At least one of the disconnectors on both sides of the two circuit breakers
Let information or cogeneration customer terminal
Pallet information of circuit breaker "OFF" or disconnection on both sides of this circuit breaker
Palette information of at least one of the "off" is ORed
A second OR circuit for outputting, with the first and second first and second root opening confirmation timer that is connected to the OR circuit, said first and second root opening confirmation timer It has a logical product circuit that outputs an isolated operation detection signal by logical product of outputs.

[0012]

The isolated operation processing section provided in the cogeneration customer terminal is connected between the first and second buses of the power substation and the cogeneration customer bus via the transmission line for the line protection relay. The "OFF" signal of each of the circuit breakers of the power supply terminal and the customer terminal and the disconnectors on both sides of these circuit breakers are input in the first and second routes respectively.

The first and second OR circuits comprise first and second OR circuits.
If any of the circuit breakers and disconnectors connected in series to the route is in the "OFF" state, the signal is output. And the first and second
If the outputs from the first and second route release confirmation timers, into which the outputs from the OR circuits respectively enter, the release of the first and second routes can be known. Therefore, based on the output from the OR circuit to which the outputs of the first and second timers are input, it is possible to detect that the first and second routes are both open and the cogeneration consumer has been operated independently.

[0014]

An embodiment of the present invention will be described with reference to the drawings.
1 shows the entire system configuration, FIG. 2 shows the circuit of the entire system, FIG. 3 shows the configuration of the islanding operation detection device, and FIG. 4 shows the processing contents of the islanding operation detection device processing section. Note 2 is customer terminal RS ₃ are omitted.

In FIGS. 1 to 3, B _US1 and B _{US2 denote} # 1 and # 2 buses of the power substation PO, B _{USA to} B _USC denote customer buses, AG denotes an AC generator of a CGS customer, and A _O1. , A _O2 ~ C
_O1 , C _O2 and M _O2 are terminals, CB is a breaker of each terminal, LS
₁ and LS ₂ are disconnectors provided on both sides of each terminal breaker CB.

Reference numerals 10 ₁ and 10 ₂ denote central relay devices provided at a power supply PO substation, MS and SS denote systems 1 and 2 of a central communication device similarly provided at a power supply substation, and RS _{1 to} RS _3.
Customer terminals, RSX in isolated operation detecting apparatus provided in CGS consumer, central relay device 10 _1, 10 ₂ and the central communication device MS, between the SS and the consumer terminal device RS ₁ to RS ₃ is They are connected by an optical transmission line composed of an optical fiber cable OF.

Each of the central relay devices 10 ₁ and 10 ₂ includes a power supply terminal unit 11 and a central processing unit 12 including a main detection relay calculation unit 13 and an accident detection relay unit 14.

The power supply terminals 11 ₁ and 11 ₂ collect and transmit voltage information, current information, and equipment information (such as a circuit breaker CB and a disconnecting switch) of M _O1 and M _O2 at a power substation, and a transfer trip. It has a function of receiving a signal and tripping a circuit breaker of a power substation.

The main detection relay operation section 13 is provided with a terminal device RS
_{1 to} RS ₃ , a function of receiving information transmitted from the power terminal units 11 ₁ and 11 ₂ , voltage information and current information of the power substation, and line protection relays of the lines Z _{1 to} Z ₄ from both information. It has a function of performing processing and bus protection relay processing of B _USA , B _USB , and B _USC , and a function of transmitting a transfer trip signal.

The fault detection relay unit 14 has a function of collecting voltage information of the power substation, performing a process of undervoltage relay and ground fault overvoltage relay, and a function of transmitting an operation signal.

The central communication devices MS and SS are provided with a line control unit.
The multiplexing / demultiplexing unit 15 has a multiplexing / demultiplexing function for data of the customer terminal device and performs line control on a loop-shaped optical transmission line.

Each of the customer terminal devices RS _{1 to} RS ₃ includes a line controller / multiplexer / demultiplexer 17 and a data conversion processor 16.

The line controller / multiplexer / demultiplexer 17 has a function of controlling a line on the loop optical transmission line and performing multiplexing / demultiplexing. The data conversion processing unit 16 has a function of collecting and transmitting customer current information and device information (CB, LS, etc.), and a function of receiving a transfer trip signal and tripping a customer circuit breaker.

The islanding detection device RSX includes a line control unit
Demultiplexing unit 18 and islanding processing units 1 system 19 and 2 system 20
It has.

The line control section / multiplexing / demultiplexing section 18 is provided with circuit breaker CB information of M _O1 and M _O2 transmitted by the power supply terminals 11 ₁ and 11 ₂ of the central relay devices 10 ₁ and 10 ₂ and the respective circuit breakers. disconnector LS _1, LS ₂ information on both sides of, and customer terminals RS ₁ ~
A _O1 , A _O2 , B _O1 , B _O2 , C _O1 , C _O2 transmitted by RS ₃
Of each breaker CB and disconnectors LS on both sides of each breaker CB
₁ , LS ₂ information is separated from the optical transmission line.

[0026] Access control unit is normally used a conventional optical fiber core OF _1, if it can not receive from the conventional optical fiber core to a control using a loopback system fiber core OF _2.

The isolated operation processing sections 19 and 20 perform the processing shown in FIG. 4 based on the separated information.

[0028] For FIG. 4, OR ₁ power supply terminal portion 11 breaker ₁ of M _O1 CB (hereinafter simply referred to as CB) and the disconnecting switch on either side LS _1, LS ₂ (hereinafter simply referred to as LS _1, LS ₂₎ of each "oFF" logical sum circuit a signal is input, OR ₂ is customer terminal CB of the device RS ₁ of a _O1, LS _1, the logic OR circuits each "oFF" signal LS ₂ is inputted, OR ₃ is the same demand House terminal device R
CB of S ₁ of A _O2, LS _1, the logic OR circuits each "OFF" signal LS ₂ is inputted, OR ₄ is CB of customer terminals RS ₂ of B _O1, LS _1, each "switching of LS ₂ OR circuit which "signal is input, OR ₅ is inputted an output of the OR circuit OR ₁ ~OR ₄ is,
An OR circuit that outputs a route 1 release signal on the lines Z ₁ and Z ₂ , and T ₁ is a release confirmation timer.

[0029] Similarly, OR ₆ ~OR ₉ Each CB B in each customer terminal apparatus _{RS 2, RS 3 O2, C} O1, C O2 supply terminal portion 11 ₂ of the M _O2, the LS _1, LS ₂ " An OR circuit to which a "OFF" signal is input, an OR _{10 to which} the outputs of the AND circuits OR _{6 to} OR ₉ are input, and an OR circuit T ₂ to output a route 2 open signal for the lines Z ₃ and Z ₄ are open check circuits. It is a timer.

A ₁ is an AND circuit which receives signals from the timers T ₁ and T ₂ and outputs a CGS disconnection command. Thus, any one of the circuit breaker CB on the route 1 and the disconnectors LS ₁ and LS ₂ becomes “OFF” and the circuit breaker CB on the route 2 side,
When any _{one of} the disconnectors LS ₁ and LS ₂ is turned off, an output is output from the AND circuit A ₁ and the isolated operation is detected.

The CGS disconnection command from the isolated operation processing sections 19 and 20 is input to the AND circuit A ₂ (FIG. 3), and the logical product of the CGS disconnection command causes the CGS disconnection circuit breaker B _O3 CB to trip.

In the above-described embodiment, the single operation processing unit has two systems, but may have one system. In the above embodiment, the number of customers is three, but when N
The sequence may be divided into route 2 and assembled.

[0033]

Since the present invention is configured as described above, the following effects can be obtained.

(1) Even when the power is balanced, it is not necessary to escape the fluctuation of the system frequency by setting the relay, and a small frequency shift can be detected.

(2) For this reason, in the case where the main protection relay operates while the loop is open and the system becomes an independent system due to an erroneous opening, the independent operation can be reliably detected even in the case of power balance.

(3) In addition, the main protection relay operation due to the occurrence of a breaker failure or a terminal failure during the operation of the loop, and the backup protection relay operation during the opening of the loop can reliably detect the islanding operation regardless of the accident state.

[Brief description of the drawings]

FIGS. 1A and 1B are configuration explanatory diagrams showing an entire system according to an embodiment. FIG.

FIG. 2 is a block circuit diagram showing the entire system according to the embodiment.

FIG. 3 is an explanatory diagram showing an outline of a system of the islanding operation detecting apparatus according to the embodiment;

FIG. 4 is a block circuit diagram showing a sequence of an isolated operation processing unit according to the embodiment.

FIG. 5 is a diagram illustrating the configuration of a conventional CGS protection relay.

FIG. 6 is an explanatory diagram of a CGS single operation case.

FIG. 7 is an explanatory diagram of a CGS single operation case.

FIG. 8 is an explanatory diagram of a CGS single operation case.

FIG. 9 is an explanatory diagram of a CGS single operation case.

FIG. 10 is a diagram illustrating the performance of a protection relay.

[Explanation of symbols]

AG ... consumer alternator MS ... central communication device 1 based RS ₁ to RS ₃ ... customer terminal RSX ... isolated operation detecting apparatus SS ... central communication apparatus 2 based 10 _1, 10 ₂ ... central relay device 15, 17 , 18 ... Line control unit / multiplexing / demultiplexing unit 16 ... Data conversion processing unit 19,20 ... Single operation processing unit

Continuation of the front page (72) Inventor Toshiro Fujimoto 2-1-1-17 Osaki, Shinagawa-ku, Tokyo Inside Meidensha Co., Ltd. (56) References JP-A-5-15067 (JP, A) JP-A-1-185141 (JP) JP-A-62-254623 (JP, A) JP-A-57-71215 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02J 3/00-5/00 H02H 7/22

Claims (1)

(57) [Claims] 1. An isolated operation detection device for a power generator in a cogeneration interconnection system with reverse power flow to a ring system, provided between a first and second power supply substations and a cogeneration customer bus. The optical transmission line is branched from the first and second optical transmission lines for the protection relay for protecting the first and second routes to the cogeneration customer terminal, and the optical transmission line is transmitted to the cogeneration customer terminal. power terminal and co the first and second routes sent from the road
-Circuit breakers for generation customer terminals and these circuit breakers
Pallet information of each disconnector on both sides and 2 of each customer terminal
A single- system or second-system independent operation processing unit to which pallet information of each of the two circuit breakers and the respective disconnectors on both sides of the two circuit breakers is provided, wherein the isolated operation processing unit includes a power supply terminal unit of the first route. Pallet of circuit breaker "OFF"
Information or at least one disconnector on both sides of the circuit breaker
"Off" pallet information or two cutoffs of customer terminals
Pallet information of the breaker "OFF" or disconnection of both sides of these two breakers
If the pallet has at least one of
-The breaker pallet of the generation customer terminal
Information or at least one disconnector on both sides of the circuit breaker
First logic to output "OFF" pallet information by OR
The sum circuit and the palette of the circuit breaker “off” of the power terminal at the second route.
Information or at least one disconnector on both sides of the circuit breaker
"Off" pallet information or two cutoffs of customer terminals
Pallet information of the breaker "OFF" or disconnection of both sides of these two breakers
If the pallet has at least one of
-The breaker pallet of the generation customer terminal
Information or at least one disconnector on both sides of the circuit breaker
The second logic that outputs pallet information of "OFF" by OR
And OR circuit alone the first and second first and second root opening confirmation timer that is connected to the OR circuit, the logical product of the outputs of said first and second root opening confirmation timer An isolated operation detection device having an AND circuit that outputs an operation detection signal.