Design Of IoT Circuit Breaker Control System

In 2019,State Grid put forward the concept of "Ubiquitous Power Internet of Things" and the goal of building a "three types and two networks,world-class" energy Internet,marking the coming era of the Internet of Things for power equipment.Circuit breakers,as an indispensable link in the field of distribution,play an important role in ensuring the normal operation of the power system.However,with the rapid development of industry,traditional circuit breakers have been unable to adapt to the increasingly complex electricity environment from the perspective of function diversification or performance reliability.Circuit breaker control system as the core part of circuit breaker is also an important factor restricting the development of circuit breaker.For a long time,Chinese chip is highly dependent on imports,and as the heart of electronic products,chip will be controlled by others everywhere if it cannot achieve complete autonomy,the importance of localization of chip replacement is self-evident.Therefore,based on domestic MCU and Free RTOS real-time operating system,this paper designs a circuit breaker control system of Internet of Things that integrates the protection function of circuit breaker with the metering function of electricity meter.Based on the national standard GB/T22710-2008 and the requirements of the State grid for Internet of Things circuit breakers,the functional requirements and related technical indicators of the system are determined,and the hardware design,software design and performance test of the system are carried out.In terms of hardware design,a hardware design architecture of "collaboration between big and small cores" is proposed: HC32F460 KCTA is used as the "big core" responsible for the main logical calculation,and HC32F002C4 PB is used as the "small core" to assist the collection of sensor data.In the aspect of current sampling,a "two-channel collaborative sampling" scheme is proposed to meet the requirements of measurement accuracy and range.The combination of wired communication and wireless communication is used to deal with the complex and changeable application environment.It adopts the redundant power supply mode which combines self-generated power supply and phase voltage power supply,and realizes the functions of line protection,measurement,communication and control with the designed peripheral circuit.In terms of software design,the embedded real-time operating system Free RTOS is transplanted.Each function of the system is divided into different sub-task modules,and different priorities are determined according to their importance.While ensuring the priority of important functions,the coupling between modules is also reduced,which is convenient for business migration and function optimization.The communication protocol is DL/T 645-2007,which is the standard protocol of State Grid.Based on this,the upper computer software platform is designed,which can not only monitor the running state of the system comprehensively,but also update the firmware program remotely.Finally,a professional experimental platform is used for hardware module testing,measurement accuracy testing,protection function testing,PC software testing and remote update testing of the designed prototype.The experimental results show that the functions and indexes of the circuit breaker control system of the Internet of Things can meet the expected design objectives,which provides development experience for the application of domestic chips in circuit breaker field.