Direct chiller power limiting for peak demand limiting control in buildings—Methodology and on-site validation

Large electricity consumers are often charged of a high price for their peak demand for the purpose of reducing the capacity and cost, as well as the operation reliability of electricity transmission facilities. As a result, even one spike in the monthly demand profile would result in a significant increase in electricity bill. Peak demand limiting techniques provide an effective and efficient means to reduce such cost. For instance, the methods to utilize cooling/heating stored in building thermal mass by resetting space air temperature set-point have been proofed effective in many studies. This study proposes a direct chiller power limiting control strategy for peak demand limiting control in buildings, particularly during the period of chiller starting when the peak demand occurs mostly. Validation tests were conducted on-site in a super high rise building and on a dynamic simulation platform. Results showed the strategy was effective in reducing the peak demand during chiller starting periods.