Non-Intrusive Method For Power Load Disaggregation And Monitoring

The energy consumption monitoring is the foundation of carrying out energy-saving work. So strengthening energy consumption monitoring, especially electrical energy consumption monitoring is of great realistic significance in improving the energy efficiency in China, carrying out the sustainable energy development, building a conservation-minded society, easing energy pressure and so on. In this dissertation, an attempt is made to implement on-line power load disaggregation monitoring applying non-intrusive method. This method breaks through the status quo of power load monitoring and realizes the disaggregation of the power energy consumption of different electrical appliances.An optimization solution method for non-intrusive power load disaggregation is presented. This method is based on the following fact, that in normal operation states of electrical appliances, steady-state currents of electrical appliances have normally certain statistical regularity. In such cases, a power load current can be approximately estimated by the linear superposition of the currents components of n main types of electrical appliances, when the power load consists of n main types of electrical appliances. The subject of the power load disaggregation is to calculate a group of reasonable weight coefficients by an optimization method, so that the estimation current has the maximum similarity with the real current. The experimental results confirmed the validity of this method.Aiming at the uncomplicated power loads, a tabular method for non-intrusive power load disaggregation is introduced. At first, all the reasonable power proportions of main types of electrical appliances of the power load are synthesized according to the power proportion interval selected beforehand. Then the estimated power load unit currents corresponding to the power proportions are calculated off-line. And the corresponding table between estimated power load unit currents and power proportions is formed. The power proportion of main types of electrical appliances of the power load can be gained on-line only by searching the estimated power unit load current that is the closest to the measured power load unit current. That is to say load disaggregation is realized. The experimental results indicate that this method of load disaggregation can effectively improve the calculation speed without affecting the calculation precision. Because this method needn't iteration, it can decrease the cost of measurement device. And it is suitable for uncomplicated power loads that include few types of electrical appliances.In the non-intrusive method for power load disaggregation, it is required that"the unit currents"are to be obtained based on field tests and accurate statistics. However, due to the multiplicity of electrical appliances and the limitations of measurement conditions, it is unattainable to obtain the unit currents of all kinds of appliances, based on separate mass sampling statistics. Aiming at this problem, a non-intrusive approximate method for obtaining unit currents parameters is proposed. This method can obtain the unit currents parameters of the main electrical appliances of power load without interfering with the normal production and life of power consumers.According to multilevel distributed structural characteristics of the non-intrusive power load disaggregation monitoring system, a monitoring system framework based on multi-agent technology is established. And the function of every agent is described detailedly. Considering the needs of power load disaggregation and monitoring, a disaggregation monitoring device based on virtual instrument has been developed and its software and hardware structure are presented. The experimental results show that this device is practical in power load on-line disaggregation monitoring.