JPH07274375A - Protective relay with automatic setting function and setting method of protective coordination - Google Patents

Abstract

PURPOSE:To provide a protective relay in which an optimum setting value for protective coordination can be operated and set automatically and to provide the application method of a pseudo-input signal for operation of a setting value with reference to a plurality of protective relays. CONSTITUTION:A protective relay 1 for overcurrent protection as an example is constituted of an overcurrent relaying part 3, of a response-characteristic analysis part 4 which, when a system-current pseudo-signal IAN is input, analyzes its change state in terms of time, of a setting-value operation part 5 which operates a required protective setting value corresponding to coordination protection with other protective realys according to its analyzed result, of an operation-value setting part 6 which automatically sets the operated setting value at the overcurrent relaying part 3 and of a changeover switch 2 in which the operating mode of the protective relay 1 is changed over to a normal operating mode (NO) and an automatic setting mode (AS). Consequently, the pseudo-current IAN which is set at a value of several % of a receiving system flows from a most upstream point within the protective range of the receiving system, a plurality of protective relays which operate coordination protection are made to respond simultaneously to an identical signal current, and an optimum protective setting value due to the utilized result of an actual installation is operated.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a protection relay related to overcurrent protection in a high voltage power receiving system and the like, and a protection coordination setting method for each protection relay when protection coordination is performed by a plurality of the protection relays.

[0002]

2. Description of the Related Art First, an example of a power receiving system in which this kind of protection coordination is performed is shown in the power receiving system diagram of FIG. Here, DS is a disconnecting switch, CB ₁ is a main circuit breaker, CB _2, CB ₃ , ... are shunt circuit breakers forming a high-voltage shunt, Tr is a step-down transformer, MCB _1, MCB
_2, ─ _, MCB _n are embedded circuit breakers in the low voltage shunt, CT _1,
CT _{2 and} CT ₃ are current transformers for measuring instruments. Also OC
R10a~10c are each overcurrent relay, for example, OCR and 10b will protect the entire power receiving system by blocking CB ₁ at the time of overcurrent detection. The OCR 10a serves as an overcurrent relay at the end of the electric power company and provides a protection signal on the upstream side of the illustrated DS.

Conventionally, in the protection relay, for example, the above-mentioned overcurrent relay, the selection of the operation setting value, that is, the selection of the tap value and the setting of the operation time period, that is, the adjustment of the lever value are both manually operated. . Further, conventionally, the tap value and the lever value in each of the plurality of protective relays involved in protection coordination of the system as shown in the figure are determined according to each protection range according to the created protection coordination diagram of the entire power receiving system. Was there.

[0004]

However, the above-mentioned conventional protection coordination diagram of the entire power receiving system is required for determining the settling value in the protection coordination regarding the tap value and the lever value as described above. Takes a lot of time and effort to create
In addition, if the power receiving system was changed and the required settling value exceeded the setting range, the protective relay itself might have to be replaced.

In view of the above, the present invention utilizes a protective relay capable of automatically determining and automatically setting an optimum settling value for protection cooperation in a short time, and an actual equipment for the protective relay. The purpose is to provide a protection coordination setting method to be performed.

[0006]

In order to achieve the above-mentioned object, a protective relay with an automatic setting function and a protective cooperative setting method according to the present invention are: 1) According to claim 1, different protection ranges are provided and the same kind of protection is performed. A protective relay that cooperates with other relays to protect the receiving system, including a protective relay section, a response characteristic analysis section that analyzes the fluctuation state of the signal to be protected compared with a predetermined characteristic in protection coordination, and its analysis. According to the result, a settling value calculation unit that calculates a required protection settling value corresponding to cooperative protection with another protection relay, a calculation value setting unit that automatically sets the calculated settling value to the protection relay unit, and The interlocking operation of the changeover switch for switching the input path of the signal to be protected to either the protection relay section or the response characteristic analysis section and the operation signal of each circuit breaker in the power receiving system or another protection relay performing a cooperative operation. A condition setting section that receives signals and determines the relay operating conditions, and automatically switches the signal input path by the changeover switch after the calculation value setting section completes setting the required settling value in the protective relay section. After that, a regular cooperative protection operation is performed by the protection relay unit.

2) According to claim 2, regarding the coordinated protection operation of the power receiving system by arranging a plurality of protective relays with the automatic setting function according to claim 1, the power receiving system is set at the most upstream point in the protection range of the power receiving system. The power source is disconnected from the power source, the downstream system from this disconnection point is the same as the configuration during actual operation, and the simulated amount of the protected signal is applied toward the downstream of the system, and the change pattern of each input signal in this state Accordingly, the protection settling value required for protection coordination is automatically calculated and set for each of the protection relays.

[0008]

[Function] Generally, the protection relay has its operation characteristics defined by the magnitude of the signal to be protected and the operation time corresponding to it. Regarding the cooperative protection operation of the power receiving system which is performed by disposing a plurality of protection relays, , The same signal input is given a predetermined time difference to achieve cooperation. That is, the operating characteristics of each protective relay are defined so that they are interlocked with each other with a predetermined time difference based on the required operating time at a specific point.

With respect to the protection relay itself, the present invention analyzes the time variation state of the signal to be protected by comparing it with the required characteristic for protection coordination, according to claim 1, and according to the result, obtains the required protection settling value. It also provides the function of automatically setting the calculated settling value to the protective relay, as well as calculating the settling value, and the protection coordination of each protection relay setting value corresponding to the protection coordination performed by combining a plurality of the above-mentioned protection relays. As a setting method, as in claim 2, for example, for overcurrent protection, the system is disconnected from the power source at the most upstream of the protection range of the power receiving system, and the downstream system from this disconnection point is the configuration during actual operation. The same amount is applied to the downstream side of the system, and the simulated amount of the signal to be protected is applied to achieve the optimum protection setting corresponding to the actual current fluctuation state.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to a circuit diagram of a protective relay with an automatic setting function of FIG. 1 and a power receiving system diagram of FIG.
First, the power receiving system diagram of FIG. 2 has the same main circuit configuration as that of the case of FIG. 3 described above.
The CRs 10a to 10c are replaced by 1a to 1c, respectively, and the circuit breaker switching state signal S _CB or S _MCB is added to each of the OCRs 1a to 1c as its operating condition signal.

Here, S _CB1 is its auxiliary contact which is closed when the circuit breaker CB ₁ is closed. Similarly, S _CB2 and S _CB2 are connected.
Each and _CB3 breaker CB ₂ and CB ₃ auxiliary contact, S
_{The MCB} buried breaker MCB _1, MCB _2, ─, an MCB _n each auxiliary contact. Next, FIG. 1 is a circuit diagram of an embodiment according to claim 1, that is, a circuit diagram of a protective relay 1 with an automatic setting function corresponding to the OCRs 1a to 1c.

In FIG. 1, reference numeral 2 is a changeover switch for switching the operation mode of the protective relay 1 between a normal operation mode (NO) and an automatic setting mode (AS), and 3 is a power receiving system after completion of setting of a required settling value. It is an overcurrent relay that is activated during normal operation. Further, 4 is a response characteristic analysis unit that analyzes the temporal fluctuation state when the simulated signal I _AN of the system current to be protected is input, and 5 is for cooperative protection with other protection relays according to the analysis result of this analysis unit 4. A settling value calculation unit that calculates a corresponding required protection settling value, and 6 is a calculation value setting unit that automatically sets the settling value calculated by this calculation unit 5 to the protective relay unit 3. As mentioned above, each element 4, 5, 6
Is for configuring an automatic setting circuit of a required settling value for the protective relay section 3, and functions when the automatic setting mode (AS) of the changeover switch 2 is selected.

The auxiliary contact signal S _CB indicating the open / closed state of the circuit breaker CB is input to a condition establishing unit (not shown), and each of the elements 4, 5 when the automatic setting mode (AS) of the changeover switch 2 is selected. , 6 to define the operating conditions. Further, the signal S _INT input via the link cable L _MS commonly connected to each OCR in FIG. 2 is the OC of each response characteristic analysis unit analysis result with respect to the simulated signal I _AN .
It is a mutual exchange signal between R and the like, and forms an external condition signal related to the protection settling value calculation in each OCR.

According to the protection coordination setting method according to the second aspect of the present invention, the received current which is the signal to be protected is simulated from the power source side of CT ₁ which is the most upstream point in the protection range of the power receiving system shown in FIG. By energizing the quantity,
The response characteristic analysis units in each of the OCRs 1a to 1c can be made to function at the same time for the same signal current, and the optimum settling value calculation for an actual machine can be performed.

Incidentally, as a simulated amount of the received current, a current of several% of the rated energizing current is passed.

[0016]

According to the present invention, there is provided a protective relay for protecting a power receiving system together with other relays, and the protective relay according to claim 1 is provided with a protective relay and a predetermined protective cooperation. Response characteristic analysis unit that analyzes the fluctuation state of the signal to be protected compared to the characteristics of the protection target, and a settling value calculation unit that calculates the required protection settling value corresponding to the cooperative protection with other protection relays according to the analysis result, A calculated value setting unit that automatically sets the settling value to the protection relay unit; a changeover switch that switches the input path of the protection target signal to either the protection relay unit or the response characteristic analysis unit; It is configured by a condition establishing unit that determines the relay operating condition by receiving the operating signal of each circuit breaker in the power receiving system or the interlocking operating signal with other protective relays that perform coordinated operation, and is required by the calculated value setting unit. With the automatic setting function that automatically switches the signal input path by the changeover switch after the setting of the fixed value to the protection relay section is completed, and thereafter performs the constant cooperative protection operation by the protection relay section. Regarding the cooperative protection operation of the power receiving system, which is performed by forming the protection relay and by arranging a plurality of the protection relays, according to claim 2, the power receiving system is used as the power source at the most upstream point in the protection range of the power receiving system. After disconnecting, the downstream system from this disconnection point was made the same as the configuration during actual operation, a simulated amount of the signal to be protected was applied toward the downstream of the system, and the protection relay settling of each protection relay in this state By automatically calculating and setting the values, it is not necessary to create a protection coordination diagram for the entire power receiving system, which was required in the past and required a great deal of time and effort, and the protection coordination It is possible to automatically determine an appropriate settling value in a short time, improve the reliability of the protection of the power receiving system and reduce the required man-hours, and respond to the system change of the power receiving system. It is possible to improve flexibility.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a protective relay with an automatic setting function showing an embodiment of the present invention.

2 is a system diagram of a power receiving system to which the relay shown in FIG. 1 is applied.

FIG. 3 is a system diagram of a power receiving system to which a protective relay according to the related art is applied.

[Explanation of symbols]

 1 Protective relay (with automatic setting function) 2 COS (changeover switch) 3 Overcurrent relay section 4 Response characteristic analysis section 5 Settling value calculation section 6 Calculated value setting section CB Circuit breaker CT Current transformer for instrument DS Disconnector MCB filling Breaker OCR Overcurrent relay Tr Step-down transformer

Claims (2)

[Claims] Claim: What is claimed is: 1. A protective relay that performs coordinated protection of a power receiving system together with other relays that perform the same type of protection with different protection ranges, the protective relay being compared with a predetermined characteristic in protection coordination. A response characteristic analysis unit that analyzes the fluctuation state of the target signal, and a settling value calculation unit that calculates the required protection settling value corresponding to the cooperative protection with other protection relays according to the analysis result,
A calculated value setting unit that automatically sets the calculated set value in the protective relay unit, a changeover switch that switches the input path of the protection target signal to either the protective relay unit or the response characteristic analysis unit, and It comprises a condition establishing unit that determines the relay operating condition by receiving the operating signal of each circuit breaker in the power receiving system or the interlocking operating signal with other protective relays that perform cooperative operation, and the required settling value by the calculated value setting unit. Protection with an automatic setting function, characterized in that the signal input path is automatically switched by the changeover switch after the completion of setting to the protective relay unit, and thereafter, the regular protective operation is performed by the protective relay unit. relay. 2. A cooperative protection operation of a power receiving system, which is performed by arranging a plurality of protection relays with an automatic setting function according to claim 1,
The power receiving system is disconnected from its power source at the most upstream point in the protection range of the power receiving system, and the downstream system from this disconnection point is the same as the configuration during actual operation, the signal to be protected toward the downstream of the system. The protection coordination setting is characterized in that the protection settling value required for protection coordination is automatically calculated and set for each protection relay according to the change pattern of each input signal in this state. Method.