Among them are a distributed relay protection device, a low-power frequency converter and an ultrasonic partial discharge detector.

The distributed relay protection device, which has been already introduced into 10-odd hydro-power stations, is higher than the previous one in sensitivity, promptness and selectivity.

In particular, the device ensures the reliability of short-circuit troubleshooting in generators and transformers at 98 percent.

The low-power frequency converter helps guarantee the stability of output power and has rich interface setting and communication functions. It is easy to operate and safe in voltage and frequency variation.

The ultrasonic partial discharge detector was applied to the Tongdaewon District Power Distribution Station under the Pyongyang City Power Distribution Station. It helps detect partial discharge caused by insulation ageing in electric equipment under operation and thus improve the safety of equipment.