ABSTRACT:
This
paper presents a single-phase high power factor motor drive system with active
power filter function. Since most of electrical equipment connected to the grid
must comply with regulations regarding grid current harmonics, motor drive
systems are generally equipped with Power Factor Corrector (PFC) which is
comprised of power switches and reactive components, e.g., inductor and
capacitor. The reactive components are bulky and increase the system cost
especially in low-cost applications such as electrical home appliances. In this
paper, a new motor drive algorithm which is capable of both driving a permanent
magnet motor and filtering the harmonic currents produced by other non-linear
loads belong to the system is proposed. Since the input current of the drive
system is directly controlled by manipulating not the motor current reference
but the output voltage reference of the inverter, it is possible to achieve
exact and immediate control of the grid current. The effectiveness of the
proposed algorithms is validated by experiments with a permanent magnet motor
drive system.
KEYWORDS:
1.
Active damping
2.
Constant power
load
3.
Dc-link capacitor
4.
Dc-link voltage stabilization
5.
Electrolytic
capacitor
6.
Power factor corrector
SOFTWARE: MATLAB/SIMULINK
BLOCK DIAGRAM:
Figure 1. Block diagram of the input current control and the active
power filter function.
Figure
2. (a) Motor currents (a-phase current in the stationary frame and d-q axes
currents in the syncronous reference frame) with the proposed input current
control, and (b) grid current, dc-link voltage, speed error and estimated
torque.
Figure
3. Experimental results : input current of non-linear load and motor drive,
grid current, dc-link voltage of both diode-rectifier (a) with the input
current control algorithm, (b) with both the input current control and the
active harmonic filtering algorithms, (c) three-phase motor currents (ia,
ib, ic), grid voltage and current.
Figure
4. (a) PFC operation at light motor load (15% motor load) , and (b) during load
change from 15% to 100% motor load.
CONCLUSION:
In
motor drive systems supplied by a single-phase grid, the problems of input
harmonic currents have been mitigated by a PFC, which makes the system bulk and
expensive. In this paper, a power factor correction method for motor drive
systems without PFC has been proposed. In the proposed system, the dc-link
capacitor is reduced for continuous conduction of diode rectifier front end.
And, the input current is controlled by directly manipulating the inverter
output voltage according to the motor currents and the input current reference.
Since the input current can be shaped into any waveforms using the proposed
input current control method, it is also possible to eliminate the harmonics in
the grid current that other electric loads generate by injecting the opposite
harmonics. It was validated by experiments that the input current can be
controlled using the proposed algorithm and the harmonic currents from other
non-linear loads can be actively suppressed.
REFERENCES:
[1] Electromagnetic
Compatibility (EMC), Part 3-2: Limits-Limits for Harmonic Current Emissions
(Equipment Input Current≤ 16 A Per Phase), International Standard IEC
61000-3-2, 2005, 2013.
[2] H. Endo, T.
Yamashita and T. Sugiura, "A high-power-factor buck converter", in
Proc. IEEE Power Electron. Spec. Conf. (PESC), pp.1071 -1076 Jun. /Jul.,
1992.
[3] L. Yen-Wu and
R. J. King, "High performance ripple feedback for the buck
unity-power-factor rectifier", IEEE Trans. Power Electron., vol.
10, no. 2, pp.158 -163, 1995
[4] B. Chen , Y.
Xie , F. Huang and J. Chen, "A novel single-phase buck PFC converter based
on one-cycle control", in Proc. IEEE Power Electron. Motion Control
Conf. (IPEMC), vol. 2, pp.1 -5 Aug., 2006.
[5]
W. W. Weaver and P. T. Krein, "Analysis and applications of a
current-sourced buck converter", in Proc. IEEE Appl. Power Electron.
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