A Statistical Method to Establish Voltage Dependency Load Parameters Based on Field Measurements

Abstract

Voltage dependency static load models are commonly applied to simulation studies on low voltage network. However, there is generally a lack of established key parameters for voltage dependency static load models to represent loads commonly used in residential premises. This paper presents a statistical approach to determine key parameters in voltage dependency static load models. Eleven (11) individual single-phase types of loads were investigated based on field measurements corresponding to on-load tapchanger operations at 33 kV upstream. Changes in active and reactive power of the individual loads due to changes in input voltages were recorded and analyzed statistically to determine the parameters used for the voltage dependency static load model. The results were validated through laboratory measurements of the individual loads and found to be consistent and in close agreement with results obtained from the statistical analysis. A simulation case study performed on a low voltage network with solar photovoltaic penetration indicates significant deviation in peak power demand, power losses, reverse power flow and energy consumption in the network between constant power load model and LTV model in particular when source voltage is set at above 1.0 per unit.  Index Terms-voltage dependency load modelling, exponential load model, power system study, low voltage distribution network.

Energy Savings for Various Residential Appliances and Distribution Networks in a Malaysian Scenario

“…The first approach is to coordinate supply with demand; however, this may not always be practical. The second best option, which might be a more practical one, is to reduce the peak load [17][18][19]. It is possible to achieve this reduction by lowering the voltage level on the distribution feeder line.…”

“…One of the most efficient ways to lower energy losses, to reduce peak demand, and to increase energy efficiency is through CVR [20]. CVR is based on the concept that voltage-dependent loads will consume less power if the voltage is reduced while remaining within a reasonable range from −6% to +10% [18].…”

“…This is equivalent to RM 240. 18. Equation ( 6) is derived and is used to compute the monthly energy consumption, where Hw is the duration of use for each appliance during the weekday, He is the duration of use for the appliance during the weekend, P is the power consumed, Ntot is the quantity of each appliance, dw is the number of weekdays (20 days), and de is the number of weekends (8 days for a month).…”