OVERTEMPERATURE DETECTING SYSTEM, OVERTEMPERATURE PROTECTING SYSTEM, AND OVERTEMPERATURE DETECTING METHOD

1 . An overtemperature detecting system detecting a temperature abnormality of a dry-type transformer cooled by a cooling device, the overtemperature detecting system comprising:

a temperature determining unit configured to determine and output a temperature abnormality of the transformer by changing determination conditions of the temperature abnormality of the transformer using operation states during operating and during stopping of the cooling device,

wherein the temperature determining unit is further configured to restrict output of an identification result of a temperature abnormality until the temperature of the transformer satisfies a predetermined temperature condition at a hot start time of the transformer.

2 . The overtemperature detecting system according to claim 1 ,

wherein the cooling device includes a fan for cooling,

wherein the transformer is installed inside a casing in which the fan for cooling is disposed, and

wherein, in a case in which the temperature of the transformer is over a first threshold temperature used for determining the temperature of the transformer at a hot start time of the transformer, the temperature of the transformer falling to be lower than the first threshold temperature is included in the predetermined condition.

3 . The overtemperature detecting system according to claim 1 , wherein, as the determination conditions of the temperature abnormality of the transformer, threshold temperatures including a first threshold temperature used for determining a temperature of the transformer during operating of a fan for cooling and a second threshold temperature used for determining a temperature of the transformer during stopping of the fan for cooling are provided.

4 . (canceled)

5 . An overtemperature detecting system detecting a temperature abnormality of a dry-type transformer cooled by a cooling device, the overtemperature detecting system comprising:

a temperature determining unit configured to determine and output a temperature abnormality of the transformer by changing determination conditions of the temperature abnormality of the transformer using operation states during operating and during stopping of the cooling device,

wherein the cooling device includes a fan for cooling,

wherein the transformer is installed inside a casing in which the fan for cooling is disposed,

wherein the temperature determining unit is further configured to restrict output of an identification result of the temperature abnormality until a predetermined condition is satisfied at a hot start time of the transformer, and

wherein, in a case in which the temperature of the transformer is over a first threshold temperature used for determining the temperature of the transformer at a hot start time of the transformer, the temperature of the transformer falling to be lower than the first threshold temperature is included in the predetermined condition.

6 . The overtemperature detecting system according to claim 1 , wherein the temperature determining unit is further configured to identify a hot start time of the transformer by detecting a transition to a hot line state of a primary side of the transformer.

7 . The overtemperature detecting system according to claim 1 , wherein the temperature determining unit is further configured to identify a hot start time of the transformer by detecting a state of an input-side circuit breaker disposed on a primary side of the transformer.

8 . An overtemperature protecting system comprising:

the overtemperature detecting system according to claim 1 ; and

a drive unit configured to open a switch disposed on a primary side of the transformer in accordance with a detected temperature abnormality of the transformer.

9 . An overtemperature detecting method for detecting a temperature abnormality of a dry-type transformer cooled by a cooling device, the overtemperature detecting method comprising:

determining and outputting a temperature abnormality of the transformer using a temperature determining unit by changing determination conditions of the temperature abnormality of the transformer using operation states during operating and during stopping of the cooling device; and

restricting output of an identification result of a temperature abnormality until a predetermined temperature condition is satisfied at a hot start time of the transformer.

10 . An overtemperature protecting system comprising:

the overtemperature detecting system according to claim 2 ; and

a drive unit configured to open a switch disposed on a primary side of the transformer in accordance with a detected temperature abnormality of the transformer.

11 . An overtemperature protecting system comprising:

the overtemperature detecting system according to claim 3 ; and

a drive unit configured to open a switch disposed on a primary side of the transformer in accordance with a detected temperature abnormality of the transformer.

12 . An overtemperature protecting system comprising:

the overtemperature detecting system according to claim 5 ; and

a drive unit configured to open a switch disposed on a primary side of the transformer in accordance with a detected temperature abnormality of the transformer.

13 . An overtemperature protecting system comprising:

the overtemperature detecting system according to claim 6 ; and

a drive unit configured to open a switch disposed on a primary side of the transformer in accordance with a detected temperature abnormality of the transformer.

14 . An overtemperature protecting system comprising:

the overtemperature detecting system according to claim 7 ; and

a drive unit configured to open a switch disposed on a primary side of the transformer in accordance with a detected temperature abnormality of the transformer.