Browsing by Author "Liao, Jhen-Yu"

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Acceleration Harmonics Reduction for Electrodynamic Shaker Fed by Cascaded H-Bridge Inverter
(2012)
Chen, Hung-Chi
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Liao, Jhen-Yu
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電機資訊學士班
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Undergraduate Honors Program of Electrical Engineering and Computer Science
For a permanent magnet electrodynamic shaker (PMEDS), an LC filter is frequently connected in series to filter out the high-frequency voltage to avoid high-frequency harmonic acceleration of the PMEDS table. This paper use a simple current control loop to avoid high-frequency harmonic acceleration instead of an LC filter which may have large size and heavy weight in high-power applications. A cascade H-bridge inverter is used in this paper to lower the output voltage harmonics and current ripple. According to the provided simulated and experimental results, it can be found that the proposed current control can improve the acceleration of the PMEDS.
Bidirectional Current Sensorless Control for the Full-Bridge AC/DC Converter With Considering Both Inductor Resistance and Conduction Voltages
(2014-04-01)
Chen, Hung-Chi
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Liao, Jhen-Yu
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電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
The full-bridge converter is often connected between the ac grid and the dc bus. In the conventional multiloop control, the inner current control loop shapes the ac-side current waveform, and the outer voltage control loop regulates the dc-bus voltage. In this paper, the single-loop bidirectional current sensorless control (BCSC) for the full-bridge ac/dc converter with considering both the inductor resistance and conduction voltage is first proposed. The average-value behavior of the full-bridge ac/dc converter is analyzed and it is simplified to an equivalent single-switch model. Based on this developed equivalent model, BCSC is designed and implemented in the FPGA-based system. There is only voltage control loop in the proposed BCSC (i.e., no current control loop), but BCSC is able to regulate the dc-bus voltage and shape the ac-side current. The provided results in both the rectifier operation and the inverter operation demonstrate the effectiveness of the proposed BCSC.
Current Sensorless Control for Bidirectional Full-Bridge Converter in DC Distributed System
(2012)
Chen, Hung-Chi
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Liao, Jhen-Yu
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電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
In this paper, the average behavior of a bidirectional AC-DC converter is analyzed and simplified to an equivalent single-switch model. Based on this single-switch model, new current sensorless control without any current loop is developed and implemented. Compared with the conventional multi-loop control, the proposed current sensorless control is able to regulate DC-side voltage and yield sinusoidal current in phase with the AC input voltage simultaneously. The provided simulation and experiment results also demonstrate the proposed current sensorless control.
Design and Implementation of Sensorless Capacitor Voltage Balancing Control for Three-Level Boosting PFC
(2014-07-01)
Chen, Hung-Chi
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Liao, Jhen-Yu
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電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
Compared with the conventional boosting PFC converter, the three-level boosting PFC converter has two cascaded switches and two cascaded capacitors across the dc-side voltage. Two capacitor voltages may be different due to their mismatched equivalent series resistance, their mismatched capacitance, and the mismatched conducting time of the corresponding switches. It follows that the controller needs to sense the capacitor voltages to balance both capacitor voltages. In this paper, the sensorless capacitor voltage balancing control (SCVBC) without sensing the capacitor voltages is proposed, and the total number of the feedback signals is saved. The proposed SCVBC is digitally implemented in an FPGA-based system. The provided simulated and experimental results also demonstrate the proposed SCVBC.
Digital Implementation of GaN-Based Inverter for Permanent Magnet Electrodynamic Shaker
(2013)
Chen, Hung-Chi
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Liao, Jhen-Yu
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電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
The maximum operation frequency of a permanent magnet electrodynamic shaker (PMEDS) is 2kHz. To provide good current tracking performance in digital implementation, the PWM frequency is chosen to be 100kHz. Due to the finite turning-on time and the turning-off time of the conventional semiconductor devices, the dead-time has a great effect on the current tracking performance and thus, the dead-time compensation loops need to be included to the current control loop. By using the high-speed high-efficiency GaN devices, the dead-time is near zero and no dead-time compensation loop is required, which simplifies the current control design and saves the calculating time of digital current loop. In addition, the results also show that the GaN devices contribute to less acceleration harmonics and less input power in the application of PMEDS.
DSP-Based Current Control for Inverter-fed Permanent-Magnet Electrodynamic Shaker
(2010)
Chen, Hung-Chi
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Lin, Yu-Ching
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Liao, Jhen-Yu
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電機工程學系
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Department of Electrical and Computer Engineering
Compared to the conventional analog-circuit control and linear power amplifier for permanent-magnet electrodynamic shaker (PMEDS), a DSP-based digital current control with switched-mode power amplifier is proposed in this paper. A full-bridge converter is connected directly to PMEDS without LC filter in order to directly regulate the shaker current and simplify the digital current control. To meet the vibration requirement of wide operating range (typically 5 similar to 2kHz), the frequency of the unipolar switching scheme is increased to 50kHz PWM frequency in order to reduce the aliasing effect of the induced voltage and current harmonic sidebands. At the same time, dead-time compensation loop is also included in the digital current control to decrease the harmonics due to the dead-time in gate signals. The effectiveness of the proposed current control is verified by the provided simulation and measured results.
DSP-Based Current Control with Dead-Time Compensation for Full-Bridge-Fed Permanent-Magnet Electrodynamic Shaker
(2012)
Chen, Hung-Chi
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Lin, Yu-Ching
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Liao, Jhen-Yu
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電機工程學系
;
Department of Electrical and Computer Engineering
Permanent-magnet electrodynamic shaker (PMEDS) can be seen as a single-phase reciprocating machine and its equivalent circuit model are an inductance, a resistance and an induced voltage in series. The induced voltage of PMEDS is near zero as the current frequency is far from the resonant frequency and its maximum operating frequency is several kHz near ten times larger than that of rotating AC machine. From the result of analysis, the dead time in gate signals has large effect on the high-frequency current tracking performance. In this paper, the PI-type controller and simple dead-time compensation loop are used to improve the current tracking performance during the range from 10Hz to 2kHz. The proposed current control is implemented in the digital DSP-based system and the full-bridge converter is connected directly to PMEDS without any LC filter. The effectiveness of the proposed current control is verified by the provided simulation and measured results.
Input Current Control for Bridgeless PFC Converter without Sensing Current
(2014-01-01)
Chen, Hung-Chi
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Chung, Chao-Chiang
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Liao, Jhen-Yu
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Yu, Sheng-Yang
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電機資訊學士班
The bridgeless power-factor-correction (PFC) converter possesses higher efficiency than the conventional boosttype PFC converter due to its reduced conduction voltage drop and conduction loss. The conventional multiloop control needs to sense the input current to yield the desired sinusoidal current waveform. This paper presents a control method for bridgeless PFC converter to provide sinusoidal current without sensing input current. The performance of the proposed method is demonstrated by the provided results with a 600W prototype.
Modeling and Small-Signal Analysis of a Switch-Mode Rectifier With Single-Loop Current Sensorless Control
(2010-01-01)
Chen, Hung-Chi
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Wu, Zen-How
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Liao, Jhen-Yu
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電控工程研究所
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Institute of Electrical and Control Engineering
The conventional multiloop control with one inner current loop and one outer voltage loop is often applied to a single-phase boost-type switch-mode rectifier where the output of the voltage loop is a current amplitude signal. In the duty phase control (DPC) proposed recently, the output of the voltage loop is a phase signal used to generate the switching signals without current loop and sensing current. To improve the clamped current waveform of DPC, a single-loop current sensorless control (SLCSC) with some nominal parameters had also been proposed to compensate for the voltage drops across the switch, diodes, and inductor resistance. In this paper, the effect of the differences between nominal and real circuit parameters on the input current waveforms of SLCSC are addressed in detail. The results are helpful in the design of SLCSC. From the simulated and experimental results, we can find that the output voltage is well regulated by the only voltage loop and the input current harmonics are significantly improved.
Modified Interleaved Current Sensorless Control for Three-Level Boost PFC Converter with Asymmetric Loads
(2014-01-01)
Chen, Hung-Chi
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Liao, Jhen-Yu
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資訊工程學系
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Department of Computer Science
Three-level boost PFC converter has advantages of lower inductor current ripple and lower switch withstanding voltage than the boost PFC converter. Interleaved current sensorless control (ICSC) had been proposed for multiphase boost PFC converters. In this paper, ICSC is modified for current sensorless control of the three-level boost PFC converter with the asymmetric loads. The modified interleaved current sensorless control (MICSC) is implemented in a field programmable gate array (FPGA) board. Simulation results and experimental results are also provided to validate the proposed MICSC.
Modified Interleaved Current Sensorless Control for Three-Level Boost PFC Converter With Considering Voltage Imbalance and Zero-Crossing Current Distortion
(2015-11-01)
Chen, Hung-Chi
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Liao, Jhen-Yu
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電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
The three-level boost power factor correction (PFC) converter has advantages of lower inductor current ripple and lower switch withstanding voltage compared with the boost PFC converter. Interleaved pulsewidth modulation had been used in the multiphase boost PFC converter. In the literature, interleaved current sensorless control (ICSC) for the multiphase boost PFC converters had been proposed. In this paper, the behavior of the three-level boost PFC converter is first analyzed. The results show that three-level converter has the same average equation as the interleaved boost PFC converter. Then, ICSC is modified for the three-level boost PFC converter with considering the voltage imbalance and the zero-crossing current distortion. The proposed modified ICSC (MICSC) is implemented in a field-programmable gate array board. Simulation results and experimental results are also provided to validate the proposed MICSC.
Modified Single-Loop Current Sensorless Control for Single-Phase Boost-Type SMR With Distorted Input Voltage
(2011-05-01)
Chen, Hung-Chi
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Lin, Chih-Chieh
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Liao, Jhen-Yu
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電機工程學系
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Department of Electrical and Computer Engineering
The first single-loop current sensorless control (SLCSC) for single-phase boost-type switching-mode-rectifier (SMR) had been proposed in the prior paper. SLCSC with sinusoidal input voltage possesses good performance, but its performance with distorted input voltage should be improved. In this paper, a modified SLCSC is proposed and implemented in a field-programmable gate array (FPGA)-based system to obtain better performance than SLCSC. Instead of the phase-shift signal in SLCSC, the inductor voltage amplitude signal becomes the output of proportional-plus-integral (PI)-type voltage controller in the modified SLCSC. The provided simulation and experiment results demonstrate the modified SLCSC.
Multiloop Interleaved Control for Three-Level Switch-Mode Rectifier in AC/DC Applications
(2014-07-01)
Chen, Hung-Chi
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Liao, Jhen-Yu
;
電機資訊學士班
;
Undergraduate Honors Program of Electrical Engineering and Computer Science
In this paper, multiloop interleaved control (MIC) is proposed, and it is combined with conventional multiloop control and the interleaved pulsewidth modulation scheme. The average behavior of the interleaved three-level switch-mode rectifier (SMR) behaves similar to the conventional boost-type SMR even though two capacitor voltages are imbalanced. It implies that conventional multiloop control can be applied to the interleaved three-level SMRs to achieve the desired power factor correction function. The proposed MIC is digitally implemented and verified in a field-programmable-gate-array-based system. The provided results show that MIC stably works and the capacitor voltages are eventually balanced during the system operations.
Multiloop Interleaved Control for Two-Switch Two-Capacitor Three-level SMR without Capacitor Voltage Balancing Loop
(2011)
Liao, Jhen-Yu
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Chen, Hung-Chi
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電機工程學系
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Department of Electrical and Computer Engineering
Compared with the conventional single-switch single-capacitor switching-mode rectifier (SMR), two-switch two-capacitor three-level boost-type SMR has advantage of low voltage stress, low current ripple and low switching loss. Due to the capacitor in series, the balance between two capacitor voltage is necessary. In order to obtain PFC function and keep the balance between capacitor voltages, additional voltage balancing loop is included into the conventional multiloop control to generate the two switching signals in the literature. But the complexity is the main disadvantages. In this paper, conventional multiloop with common interleaved control is proposed to generate the two switching signal without voltage balancing loop and without sensing any capacitor voltage. The proposed multiloop interleaved control is digitally implemented in a FPGA-based system. From the provided simulated and the experimental result, the PFC function is obtained and the capacitor voltage are equal to each other. It shows that the proposed multiloop interleaved control operates stably.
PMSM Sensorless Control with Coordinate Rotation Digital Computer
(2010)
Chen, Hung-Chi
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Huang, Wei-Shun
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Liao, Jhen-Yu
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電機工程學系
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Department of Electrical and Computer Engineering
Coordinate Rotation Digital Computer (CORDIC) is usually used to obtain the angle information without any multiply and division operations. The extended electromotive force (extended-EMF) in the literature shows that the angle error between the rotor reference frame and the assumed reference frame can be estimated from an arctangent function and a division. In this paper, the sensorless control for permanent-magnet synchronous motor (PMSM) is designed and implemented based on the CORDIC algorithm. Compared to the calculation of the arctangent function and division operation, CORDIC-based algorithm is able to save calculating time and memory resource. The provided simulation and experimental results also demonstrate the proposed CORDIC-based sensorless control.