Rookie question: What do these parameters of voltage transformers and current transformers mean?
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What do the following parameters mean?: Voltage transformer: 630KVA 20(10)/0.4KV Current transformer: 50/5A 0.2S/0.2 10VA/10VA Is VA not W? Why not write it directly as W?
Which one in front should be the transformer? Is there a 630KVA voltage transformer? It means the capacity is 630KVA, the high-voltage side voltage is 20KV, there are 10KV high-voltage terminals, and the low-voltage measurement voltage is 0.4KV. Current transformer: primary side rated current 50A, secondary side rated current 5A, accuracy level 0.2 measurement, level 0.2 protection.
What is a 10KV high-voltage terminal? The voltage on the high-voltage side of the transformer is 20KV. The high-voltage terminal is only 10KV. Is that enough?
Sorry, let me ask, this voltage transformer: 630KVA 20(10)/0.4KV. Is it a voltage transformer? It should be a transformer, right? Capacity is 630KVA, high voltage side 20(10)kv, low voltage side 0.4kv
Just to add: 10VA refers to the secondary load of the current transformer, usually represented by resistance or capacity. ； 20kV (10kV) is a dual-voltage transformer. Its high-voltage winding uses two parts with the same structure. The incoming and outgoing terminals are led to the outside of the high-voltage coil. When connected in series, it acts as a 20kV transformer, and when connected in parallel, it acts as a 10kV transformer.
By the way, there should be almost no 20kV transformers in China, right? It seems useful in Singapore?
What do the following parameters mean?: Voltage transformer: 630KVA 20(10)/0.4KV Current transformer: 50/5A 0.2S/0.2 10VA/10VA Is VA not W? Why not write it directly as W? 630KVA is a voltage transformer with such a large capacity. This is the capacity of a transformer. The transformation ratio below the voltage is the high-voltage winding of 20KV or 10KV, and the low-voltage winding is 400V. This is a transformer. VA and W cannot be confused. VA is the capacity, W is the power. The transformation ratio of the voltage transformer is mostly 10/√3/0.1/√3/0.1/3 for example 10KV. The current transformer 50/5 is the transformation ratio, that is, the primary side current is 50, and the secondary side is 5A. The following is the accuracy level. 0.2S is for measurement only, and the error is 0.2%. S is the accuracy at small currents. 10VA/10VA is the capacity of the two secondary windings.
Regarding the transformer, I agree with what the 5th floor said. 20kV (10kV) is a dual-voltage transformer. Its high-voltage winding uses two parts with the same structure. The incoming and outgoing terminals are led to the outside of the high-voltage coil. When connected in series, it acts as a 20kV transformer, and when connected in parallel, it acts as a 10kV transformer. 630kVA is the capacity of the transformer. KVA is different from KW. One is apparent power and the other is active power. There is a power factor conversion relationship. Regarding the current transformer, I agree with the 7th floor and add something: 0.2S/0.2 means that the CT has 2 windings, one with an accuracy level of 0.2S and one with an accuracy level of 0.2. The error is 0.2% at rated current. However, the accuracy range of 0.2s level is wider, and the accuracy requirement of 0.2% can be met at about 20% of the rated current.
630KVA is a relatively small transformer, usually 1600KVA or 2000KVA.