Study on Evaluation of Sampling Test Efficiency for Distribution Transformer

Distribution transformer (DT) is an important part of the power industry. The capacity of DT industry has reached or exceeded 30 billion KVA in China with a serious surplus. The DT quality risk increase with the fierce completion. Sampling test is an important quality control method for DTs taken by the users. There are many kinds of sampling test strategies. It is of great significance to study the method of sampling efficiency evaluation. The comprehensive evaluation method is put forward based on the pass rates of test items and products. The advantage of this evaluation method is that the effectiveness of different sampling strategies can be compared. The effectiveness of the method is verified by an example.