An improved closed loop hybrid phase shift controller for dual active bridge converter

Abstract

In this paper, a new closed loop hybrid phase shift control is proposed for dual active bridge (DAB) converter with variable input voltage. The extended phase shift (EPS) control is applied when load gets heavy enough and the secondary side phase shift angle decreases to zero. When this modified DAB converter operates at light loads, the triple phase shift (TPS) modulation method is applied, and the added control freedom is the secondary phase shift angle between the two-secondary side switching legs. The hybrid phase shift control (HPS) scheme is a combination of EPS and TPS modulations, and it provides a very simple closed form implementation for the primary and secondary side phase shift angles. Depending on the application by changing the phase shift angles we can achieve Buck or Boost operation. A characteristic table feedback control method has been used for closed loop operation. By using 1D look up table the proposed DAB converter provides constant 400V for any given input voltage.

The assesement of the shunt active filter efficiency under varied power supply source and load parameters

“…Also, in case of adjustment of the active filter on-side, it is very difficult to chose and tune the parameters of regulators if the real parameters of the power system differ from those designed. This fact has been proven during our experimental research experience [7,8]. The above-mentioned facts illustrate a very important, serious, and actual problem of the theory and methodology of structural and parametric synthesis of electrical complexes for power quality improvement on the basis of active and passive filters [43].…”

“…The first stage is the selection of character control ways from all plenty of the existing methods and theories for the further research. According to the results of numerous theoretical and experimental studies [7,8,[21][22][23][24][25][26], the ways developed for the determination and correction of power quality indicators for shunt active filter control may be divided into three main groups [27][28][29][30]:  Ways based on discrete (DFT) and fast Fourier (FFT) transformations [31][32][33][34][35].  Ways that extract the reference values of current or voltage using the theories and methods of current physical components (CPC) [22,23,36].…”

“…All parameters of the developed model, including the parameters of the source, power line, load node, and shunt active filter, were the same for each studied control way. These parameters were selected according to the results of experimental research [7,8]. The initial parameters of the shunt active filter were set according to the optimal relationship between the rated current of the non-linear load Inn and the rated current of the filter Isaf detected during experimental research [7,8] using the criterion of harmonic minimization:…”

“…It is undeniable that ensuring power quality improvement and electromagnetic compatibility is critical in centralized power supply systems, distributed generation systems, and combined power supply systems [1][2][3][4]. The main negative influences of the poor power quality level on electrical equipment and power supply systems are well-known and have been studied in detail [5][6][7][8][9][10]. In particular, this problem has become more significant considering the intensive development of technologies and the principles of distributed generation from alternative and renewable power sources and combined power systems, where both centralized and distributed sources work in parallel mode.…”

“…Among them it is reasonable to indicate passive and active devices [5]. Passive devices are not so effective in the conditions of combined power systems [7]. Active devices, such as the shunt active filters, are able to improve power quality in the adaptive mode by means of the special control methods and algorithms [9].…”