Design Of Emergency Management And Control System For Controllable Loads In Smart Grids

Power system is an indispensable pillar of economic development and any power failure within short-term may cause huge economic losses.The power system is currently moving towards the smart grids to provide a high level of power supply service.Traditional power grids only consider control from generation side,when the area power supply fails,the loads can only passively stop the power supply and take a long time to wait for maintenance.As an important part of the power grid,loads can actively participate in emergency events will effectively improve the safety and stability of the power grids.The smart grids enable the power-supply side and the load side to participate in the control and management for emergency events simultaneously,which greatly improves the ability to handle emergency events.Traditional power grids are typically managed in a centralized manner,while the loads have a large number of geographically dispersed features,making centralized control unsuitable for loads management.The intelligent controllable loads simplify the difficulty of emergency management and control due to their power adjustability,while the specific strategy remains to be studied.Thus,it is of great significance to do research on intelligent controllable loads of emergency management.This paper focuses on the emergency problem of insufficient power supply,reasonable scheduling and control of the controllable loads are designed,so that the cost of scheduling is minimized.And the distributed power supply is used to provide emergency power supply to the scheduled loads,thereby improving the power supply capability on the load side.The main research content of this paper consists of the following three parts:(1)A mathematical model of scheduling optimization is established for the controllable loads emergency problem when the power supply is insufficient.By designing the prediction algorithm to estimate the power shortage,a distributed scheduling algorithm is proposed by using the alternating direction multiplier method(ADMM),and the stability of the proposed algorithm is rigorously proved.The algorithm makes the load guarantee the minimum scheduling cost under the constraints of scheduling power inequality constraints and total scheduling balance requirements.Finally,the effectiveness and correctness of the algorithm are verified by numerical simulation.(2)For the scheduling power value calculated by the optimization algorithm,the load-shedding strategy and the re-power supply control method are designed.By analyzing the relationship between the load active power and voltage,a load-shedding control strategy is designed.At the same time,for some island users with self-generation capabilities,the constant frequency and voltage recovery problem of load inverter control is studied.A voltage and current double closed loop control strategy based on PI control is designed.Then,the effectiveness of the control strategy is verified by numerical simulation.(3)An emergency power supply experimental platform for distributed power supply was built based on the inverter.The platform is powered by a DC voltage source and the DSP-TMS320F28335 is used as the main control chip.For the proposed control algorithm,hardware and software design were carried out respectively to realize the control of distributed power supply.The effectiveness of the proposed strategy is verified by experiments.