Multi-user energy meters, as terminals for smart grids, have gradually come into their lives. According to statistics, China has now completed the installation of about 258 million smart meters, and there are still about 70 million new and replacement needs each year. The multi-user energy meter external miniature circuit breaker is the key equipment for cooperating with the intelligent energy meter to complete the intelligent charge control function. The intelligent energy meter with a relatively large rated current (> 60A) generally chooses an external circuit breaker to complete various charge control. function.
At present, the cost control functions of domestic multi-user energy meters are divided into two categories: semi-active and full-active:
One is a semi-active type, which is a miniature circuit breaker or relay with shunt trip function. This product is an ordinary relay equipped with an electromagnetic device or an independent relay that can trip the miniature circuit breaker. When the time is in arrears, the smart meter sends a signal to energize the coil of the electromagnetic device to control the miniature circuit breaker to trip or make the relay actuate to complete the function of active power off. However, this product can only be powered off automatically after completing the arrears. Professionals must manually close the switch after payment. For this reason, although the grid company has invested huge labor costs for maintenance, it still cannot handle the timeliness of power renewal. Greatly reduced the customer's experience of electricity consumption. This product also has the following shortcomings. One is that it cannot meet the requirements of the intelligent control system for terminal electricity cost control. The other is that the space is limited after the electromagnetic device is installed in the miniature circuit breaker, which causes the N phase of the miniature circuit breaker to be abnormal. Discontinued maintenance.
The second is fully active, which can be completed by two types of equipment:
One is to use a relay-type active recloser. The main body is a relay + electronic circuit board. However, because the relay does not have arc extinguishing and breaking capabilities, short-circuit maintenance cannot be completed. When it passes a large current, contact welding is likely to occur and affect power The peace of the system.