# Parametric PSpice Circuit of Energy Saving Lamp Emulating Current Waveform
## 2 Related Works
In such a work the design of a filter circuit for harmonic reduction in lighting system applications has been considered. Different LED light bulbs have been compared in [58], focusing on the current harmonic emission and, consequently, on the negative impact on the distribution grid. In [59], a method to examine the effect on harmonic distortion levels in the distribution network through a custom software has been proposed. Although the current distortion has been investigated in these works, there were not developed any model able in predicting the distorted current. Although the harmonics due to the ESLs have been studied in these works, they do not provide any method to esteem the harmonic distortion due to them. Several works have treated the prediction of the amount of current harmonic that the ESLs inject into the power grid [60; 61; 62; 63; 64; 65; 66; 67; 68; 69; 70; 71; 72]. In [60] has been investigated the effect of the employing of many energy-saving lamps on the power grid in New Zealand. A Norton equivalent has been used to emulate a large number of houses assumed as series of distributed loads. The main objective of [61] has been the prediction of the maximum number of CFLs that can be used without overcome a threshold value of THD imposed by the users. In [62] the results of a research performed on energy-efficient electronic ballasts for T8 fluorescent lamps have been presented. Unlike the previous cases, the CFL behaviour in a distribution system a fixed harmonic injection method has been adopted, where the single CFL has been modelled by means of an ideal current source. In this way, a possible solution developed in the PSCAD/EMTDC environment to model the CFL ballast circuit has been proposed in [63]. The solution analysed the interactions of several CFLs connected to an electrical network at the same time. It has been studied the error between the measured current waveform and the ones obtained through the fixed harmonic current injection. Moreover, the tensor analysis with phase dependency is used with the aims to take into account the harmonic interaction of the mains voltage in the CFL harmonic currents. The analysis of the power factor and harmonic emission of CFLs have highlighted that the current drawn of the lamps are influenced by the main voltage variation [60; 61; 62; 63]. Consequently, when multiple CFLs interact together through the AC system impedance, the harmonic current injection method is not always accurate. In [64], the black box CFL behaviour is obtained analysing the current waveform drawn as a function of the main voltage applied. The current has been modelled by a mathematical function given by the difference between two exponentials. Even if many results have been accurate, some particular CFLs under test have had to use some ad hoc adjustment to fit accurately with the measurements. Some researchers have worked out the behaviour of the CFL using an equivalent electrical circuit [65; 66; 67; 68; 69; 70; 71; 72]. A common and general model is depicted in Figure 1, where the key circuit components are: a diode bridge that rectifies the main voltage, an AC equivalent resistor (_Rac_) and a DC smoothing electrolytic capacitor (_C_) supplying the downstream inverter that, in turn, feeds the fluorescent tube. Both the inverter and the fluorescent tube can be modelled as a unique equivalent resistance, \(R_{D}\), since they behaviour like to a constant load for the DC busbar. In [65; 66] an admittance model that depends on some internal parameters (firing and extinction angles) that, in turn, depend on the voltage waveform being used instead of the general model. A method based on the measurements to obtain harmonic models of power electronic-based home appliances, among which ESLs, has been presented in [65]. In [66] a model based on harmonically coupled admittance matrix used to study harmonics in static converters of ESLs have been proposed. However, admittance model it is valid only in a specific condition of the supply voltage.