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Dual boost PFC converter configuration.
Source publication
The combination of voltage feedforward and feedback control is a conventional approach for correcting the power factor in single-phase ac-dc boost converters. The feedback duty ratio increases significantly with an increase of the line frequency and input inductance. Therefore, the performance of the conventional approach is highly dependent on the...
Contexts in source publication
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... the dual boost converter, as shown in Fig. 1, with an input inductor, L, and its parasitic resistor, R, Kirchhoff's voltage law with the source voltage, v s , the switch voltage, v d and the input line current, i s , ...
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... d is the average on-time duty ratio of the switches, and v o is the dc output voltage shown in Fig. 1. By combining (1) and (2), the equation can be rewritten ...
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... switching frequency applications. For an evaluation of the performance, the converter operation under three control strategies with a 1 kHz bandwidth of the current compensator was simulated: 1) without employing any feed-forward controllers, 2) with the conventional voltage feedforward control, and 3) with the proposed IIC feedforward control. Fig. 10 compares the steady state input current waveforms obtained when the source voltage was 110Vrms/60Hz. It is worth noting that with a band-limited compensator, the leading-phase effects and the zero-crossing distortions of the input current are observed at the nominal input frequency (60Hz), as shown in Fig.10(a). However, these ...
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... 10 compares the steady state input current waveforms obtained when the source voltage was 110Vrms/60Hz. It is worth noting that with a band-limited compensator, the leading-phase effects and the zero-crossing distortions of the input current are observed at the nominal input frequency (60Hz), as shown in Fig.10(a). However, these distortion factors completely disappear, as shown in Fig. 10(b) and Fig. 10(c), when the feedforward methods are applied. ...
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... waveforms obtained when the source voltage was 110Vrms/60Hz. It is worth noting that with a band-limited compensator, the leading-phase effects and the zero-crossing distortions of the input current are observed at the nominal input frequency (60Hz), as shown in Fig.10(a). However, these distortion factors completely disappear, as shown in Fig. 10(b) and Fig. 10(c), when the feedforward methods are applied. Similarly, at a high input frequency (400Hz), the distortion and displacement factors of the input current are significantly worsened, as shown in Fig. 11(a) and Fig. 11(b), due to the lagging-phase effects. Meanwhile a significant reduction in terms of the displacement value ...
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... obtained when the source voltage was 110Vrms/60Hz. It is worth noting that with a band-limited compensator, the leading-phase effects and the zero-crossing distortions of the input current are observed at the nominal input frequency (60Hz), as shown in Fig.10(a). However, these distortion factors completely disappear, as shown in Fig. 10(b) and Fig. 10(c), when the feedforward methods are applied. Similarly, at a high input frequency (400Hz), the distortion and displacement factors of the input current are significantly worsened, as shown in Fig. 11(a) and Fig. 11(b), due to the lagging-phase effects. Meanwhile a significant reduction in terms of the displacement value has been achieved ...
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... at the nominal input frequency (60Hz), as shown in Fig.10(a). However, these distortion factors completely disappear, as shown in Fig. 10(b) and Fig. 10(c), when the feedforward methods are applied. Similarly, at a high input frequency (400Hz), the distortion and displacement factors of the input current are significantly worsened, as shown in Fig. 11(a) and Fig. 11(b), due to the lagging-phase effects. Meanwhile a significant reduction in terms of the displacement value has been achieved in the proposed controller when compared to the conventional voltage feedforward controller, as shown in Fig. 11(c VI. EXPERIMENTAL RESULTS Fig. 12 shows a prototype ac-dc and dc-dc converter for a ...
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... input frequency (60Hz), as shown in Fig.10(a). However, these distortion factors completely disappear, as shown in Fig. 10(b) and Fig. 10(c), when the feedforward methods are applied. Similarly, at a high input frequency (400Hz), the distortion and displacement factors of the input current are significantly worsened, as shown in Fig. 11(a) and Fig. 11(b), due to the lagging-phase effects. Meanwhile a significant reduction in terms of the displacement value has been achieved in the proposed controller when compared to the conventional voltage feedforward controller, as shown in Fig. 11(c VI. EXPERIMENTAL RESULTS Fig. 12 shows a prototype ac-dc and dc-dc converter for a battery charger. ...
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... and displacement factors of the input current are significantly worsened, as shown in Fig. 11(a) and Fig. 11(b), due to the lagging-phase effects. Meanwhile a significant reduction in terms of the displacement value has been achieved in the proposed controller when compared to the conventional voltage feedforward controller, as shown in Fig. 11(c VI. EXPERIMENTAL RESULTS Fig. 12 shows a prototype ac-dc and dc-dc converter for a battery charger. For the ac-dc converter, a single-phase dual boost converter based on a low-cost digital control was used to verify the proposed IIC feedforward control. Table I lists some of the important experimental values. Fig. 13 shows experimental ...
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... of the input current are significantly worsened, as shown in Fig. 11(a) and Fig. 11(b), due to the lagging-phase effects. Meanwhile a significant reduction in terms of the displacement value has been achieved in the proposed controller when compared to the conventional voltage feedforward controller, as shown in Fig. 11(c VI. EXPERIMENTAL RESULTS Fig. 12 shows a prototype ac-dc and dc-dc converter for a battery charger. For the ac-dc converter, a single-phase dual boost converter based on a low-cost digital control was used to verify the proposed IIC feedforward control. Table I lists some of the important experimental values. Fig. 13 shows experimental results comparing the ...
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... controller, as shown in Fig. 11(c VI. EXPERIMENTAL RESULTS Fig. 12 shows a prototype ac-dc and dc-dc converter for a battery charger. For the ac-dc converter, a single-phase dual boost converter based on a low-cost digital control was used to verify the proposed IIC feedforward control. Table I lists some of the important experimental values. Fig. 13 shows experimental results comparing the performances of the conventional feedforward controller and the proposed IIC feedforward controller. Both of them have a 1 kHz bandwidth current compensator. Fig. 13(a) and Fig. 13(b) show the input current and voltage at the nominal input frequency (60Hz). When feedforward controllers are ...
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... a low-cost digital control was used to verify the proposed IIC feedforward control. Table I lists some of the important experimental values. Fig. 13 shows experimental results comparing the performances of the conventional feedforward controller and the proposed IIC feedforward controller. Both of them have a 1 kHz bandwidth current compensator. Fig. 13(a) and Fig. 13(b) show the input current and voltage at the nominal input frequency (60Hz). When feedforward controllers are employed, an exceptionally high performance with a low distortion factor and a low displacement factor can be seen. However, the input current shown in Fig. 14(a), using the conventional feedforward controller, is ...
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... Both of them have a 1 kHz bandwidth current compensator. Fig. 13(a) and Fig. 13(b) show the input current and voltage at the nominal input frequency (60Hz). When feedforward controllers are employed, an exceptionally high performance with a low distortion factor and a low displacement factor can be seen. However, the input current shown in Fig. 14(a), using the conventional feedforward controller, is displaced significantly at a high input frequency (400Hz) due to the effect of uncompensated lagging-phase admittance. Meanwhile, the input current shown in Fig. 14(b), using the proposed IIC feedforward control, is less displaced and still has an acceptable PFC performance with a low ...
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... high performance with a low distortion factor and a low displacement factor can be seen. However, the input current shown in Fig. 14(a), using the conventional feedforward controller, is displaced significantly at a high input frequency (400Hz) due to the effect of uncompensated lagging-phase admittance. Meanwhile, the input current shown in Fig. 14(b), using the proposed IIC feedforward control, is less displaced and still has an acceptable PFC performance with a low bandwidth compensator which indicates a reduced ratio of the switching frequency to the input ...
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Citations
Conventionally, a proportional-integral (PI)-based dual-loop control strategy, in which both the dc-bus voltage and the inductor current are regulated, is utilized to control ac/dc converters with power factor correction (PFC). Due to the characteristics of the PI controller, converters experience poor control performance such as current distortion and slow dynamic response. This paper proposes a novel cascaded proportional control in conjunction with algebraic estimation method for PFC ac/dc converters. Different from the conventional control system, the average dc-bus energy and the instantaneous input power of the converter are regulated. Moreover, system nonlinearity, load power and uncertainties are estimated by incorporating algebraic estimators. A holistic design of controller parameters and stability analysis are presented based on the
z
-domain transfer functions. A 1 kW PFC ac/dc prototype is designed and experimental results demonstrate the effectiveness of the proposed control scheme.
Reactive power compensation is important not only for power system stability but also efficient use of the power transmitted through the electric grid. Although many power electronics-based technologies such as flexible alternating current transmission systems and active power filters have emerged to overcome the shortcomings of traditional passive shunt compensation methods, they may not be the best solution for improvement of power quality of an entire power system due to high capital and operating costs, as well as additional inherent power losses. Usually, unidirectional power factor correction converters are utilized in many commercial applications as front-end circuitry in order to minimize the effects of harmonics distortion and poor power factor. Since these converters are commonly used, they have great potential as huge reactive power compensators in distribution level power systems. However, the distortion of input current as a result of reactive power compensation cannot be avoided due to intrinsic topology limitations. This drawback can be mitigated by employing bidirectional converters which would be incorporated in electric vehicles and photovoltaic systems, which are becoming increasingly available as residential distributed generation systems. The objective of this dissertation is to investigate reactive power capabilities of aggregated unidirectional converters and to propose cost-effective residential distributed generation systems with maximized local reactive power support capabilities. The proposed approaches are as follows: 1) to investigate functionalities of unidirectional converters as active power filers, 2) to analyze and design control algorithms for unidirectional and bidirectional converters in residential distributed power systems, and 3) to harmonize unidirectional and bidirectional converters in order to obtain harmonic-free reactive power support. The current distortion of the unidirectional converter under reactive power compensation is analytically explained and the performance of unidirectional converters as an active power filter is evaluated. Power control methods of bidirectional converters in photovoltaic and vehicle-to-grid systems are investigated. Finally, an integration strategy for controlling bidirectional and unidirectional converters is proposed. The outcome of this dissertation is to get free reactive power support using the existing resources without harmonic pollution in residential distributed generation systems.
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