Abstract
DC power equipment in the electricity industry as an emergency power supply , providing a series of reliable protection,including control, communications, signals for the power grid. Circuit breaker as the main equipment and components to protect the DC power distribution system and supply line which are used to the protection and control equipment of power system.
DC circuit breaker is a electrical equipment of protection system , when the load short-circuit, the resulting short-circuit current through the electromagnetic coils so that circuit breakers have an instant-powered action. "Double metal" is overload protection device, when the load current beyond the rated current of a certain value, the resistance wire around the dual-metal begins heating, metal bending action played the purpose of overload protection. The second test software procedure of DC circuit breaker in Microsoft Visual C++6.0 development environment is the subject of designed the DC circuit breaker imposed by different multiples of rated current to test the time of circuit breakers off, the test system is divided into single-point test (each test a current ratio), multi-point test (for testing a number of current ratio) and differential test (number of circuit breakers cascade testing), at the same time draw curve seconds. This paper introduces a DC circuit breaker, MFC Programming，the serial communications under the Visual C++, the subject applied to the design of the Visual C++6.0 and its development environment for debugging Keywords： DC circuit breakers; Visual C + +; serial communication；MFC Programming
