Development and application of hardware-in-the-loop simulation for the HVAC systems

The hardware-in-the-loop (HIL) employs the real controller and true signal transmission, which is efficient to test control algorithms for the situation that is inconvenient to conduct experiments. The design method of hardware-in-the-loop is presented for buildings, in which the HVAC system is simulated while the control system including controllers, A/D and D/A modules are real. The controllers embedded with control algorithms are integrated with the simulation of HVAC system. The HVAC HIL test platform is constructed so as to evaluate the candidate control strategies. The feature of HVAC HIL test platform is compared with the pure TRNSYS based simulation. The comparison tests show that pure simulation doesn?t match the true control process while the HIL platform does and provides the credible control response. With real signal transmission and controllers, the control algorithms can be tested authentically. Moreover, the fault detection and diagnosis (FDD) models using basic and improved principal component analysis (PCA) are evaluated in HVAC HIL platform. Through HIL tests, the unobservable application problem of basic PCA model is discovered. An improved wavelet-PCA model is developed, which has the satisfied efficiency to detect the various biases of sensors.