The Reasearch And Development On VRV Air-conditioning Control System By Semi-physical Simulation Platform

Variable refrigeration volume air conditioner (VRV) is widely used recently due to its merits such as energy-effective, comfort and attractiveness. Generally, the VRV system consists of an outdoor unit and multiple indoor machines. The outdoor unit is responsible for energy supply, and the indoor units are responsible for energy distribution, to meet different load requirements. Both the interaction between the indoor units and the load's changing, so the VRV system is an uncertainty, coupled multi-variable complex system. It is a key issue for VRV system to obtain the enery-saving, efficient and comfortable control. in researching and developing on VRV system.Considering the status of national research on the VRV air-conditioning control system, which lack of research fruit and core technique is enslaved to foreign country, and the control researcher do not have cooling/heating engineering knowledge, who disable to study controller by separately, so this paper design and build a set of VRV air-conditioning control system for semi-physical simulation platform independently. The semi-physical simulation platform is developed by Visual C++ and hardware in the loop technology. The temperature of room and other states are simulated via the mathematical model of evaporation-compression period and greenhouse room.The platform consists mainly of two parts, physical and simulation.The development of physical part based on the CPU of dsPIC33FJ128MC506 embedded controller, the inverter main circuit module, communication network module, human-computer interaction module are optimized and designed according to the characteristics of the HIL. In addition, process control algorithm is developed to realize the general-purpose and powerful embedded control system and software/hardware design of testing system.Simulation component is to develop a monitoring software.This paper utilize a common structure of simulation software--simulation editing+simulation control software, which extract simulation plant's information from simulation software and to store the information as XML documents. Moreover, the simulation object's formula is made as separated DLL files, which separate the information editing process and controlling process of simulation. This gives the monitoring software a better flexibility and versatility.The simulations of PID control algorithms under a variety of operating conditions are carried out on the semi-physical simulation platform. These simulation results demonstrate that the platform proposed in this paper is feasible and is much in line with the law, it can accurately simulate the operating characteristics of VRV air-conditioning control system. Meanwhile, researchers of other disciplines can do testing on this platform, such as simulating modeling, derivation, validation, or testing of control algorithms to find the optimal control parameters. Therefore, this platform is comprehensive, highly repetitive, safe and economic, of results controllable, free from climatic conditions and to space constraints, etc., which will improve the efficence.of control scheme research.