Harmonic minimisation in microprocessor controlled current fed PWM inverter drives

Novel On-Line Microprocessor Generation of Harmonic Elimination and Minimisation PWM Control Strategies using Regular-Sampling Techniques

“…PWM CSI strategies to be used [21]. For example, experimental results which demonstrate the feasibility of generating a 17-pulse (per half-cycle) PWM current strategy, which eliminates current and torque harmonics up to 29th and 30th respectively, previously thought to be impracticable, is shown in Fig 11. It has been shown earlier [21] that, although the harmonic-elimination approach can be highly effective in preventing low-frequency mechanical resonances of the motor-load transmission system, it is not necessarily optimal in improving the quality of the rotor motion of the drive motor a low speeds.…”

“…It has been shown earlier [21] that based on certain approximations the performance functions adopted to reduce Aw,(t) and ApE(t) can be defined as Time-domain techniques which considerably simplify the calculation of F 1 (a) and F 2 (a), and thus significantly speed-up the computation of the switching angles, ako have been presented earlier [21].…”

“…These fast modelling techniques have been used as a basis for developing very simple closed-form analytic expressions for ~w,(t) and ~PE (t), which when included into the minimisation procedure provide extremely efficient optimal PWM solutions [22). Experimental and CAD results demonstrating the application of these optimal ,,,.-( PWM strategies have been presented in some detail previously for the conventional CSI drive [22,23] (120° conduction), the series connected CSI (SCCSI) drive [24] (180° conduction) consisting of three single-phase bridges in series, and the duplex CSl drive [19,21] consisting of two 120° CSI's in parallel.…”

Determination of Iron Loss Distribution in Inverter Fed Induction Motors

“…To overcome this problem, the system drive designer can adopt one of two strategies; either the inverter design is optimised to minimise the harmonic voltages and currents, or the motor is designed to minimise the additional losses due to harmonics. In the former method selective harmonic reduction [2,3] and real time modulation techniques [4] have been successfully used. Whilst these methods give good waveform purities the expense of more complex control and power circuit configuration have restricted their widespread application.…”

Διαμόρφωση Ηχητικών Σημάτων Κατά PWM Για Υλοποίηση Πλήρως Ψηφιακών Ενισχυτών

“…Η PWM διαµόρφωση αρχικά χρησιµοποιήθηκε σε τηλεπικοινωνιακές εφαρµογές για την µετάδοση/λήψη αναλογικών σηµάτων [17]. Στη συνέχεια, χρησιµοποιήθηκε για την κατασκευή τροφοδοτικών/µετατροπέων ισχύος [55], [56], ενώ, επίσης, απετέλεσε τη βάση για ανάπτυξη εφαρµογών ενίσχυσης ισχύος αναλογικού ηχητικού σήµατος (ενισχυτές τάξης D, BD κ.λ.π) [18], [21]. Τα τελευταία χρόνια, όπως αναφέρθηκε και στο προηγούµενο κεφάλαιο, η PWM αποτελεί το επίκεντρο του ενδιαφέροντος πολλών ερευνητικών προσπαθειών προς την κατεύθυνση υλοποίησης πλήρως ψηφιακών ενισχυτών ηχητικού σήµατος [37], [60].…”