scholarly journals Control of Dual-Output DC/DC Converters Using Duty Cycle and Frequency

2020 ◽  
Vol 11 (4) ◽  
pp. 72
Author(s):  
Yoshinori Matsushita ◽  
Toshihiko Noguchi ◽  
Kazuki Shimizu ◽  
Noritaka Taguchi ◽  
Makoto Ishii
Keyword(s):  
Power Systems ◽  
Duty Cycle ◽  
Control Method ◽  
Frequency Control ◽  
Maximum Efficiency ◽  
Control Factors ◽  
Series Resonant ◽  
Bridge Rectifier ◽  
Bridge Circuits ◽  
Resonant Filters

As part of the integration process of the auxiliary power systems of electric vehicles, plug-in hybrid vehicles and fuel cell vehicles, this study proposes a method to control two different voltage types using two control factors of the rectangular alternating waveforms contained in DC/DC converters, namely the duty cycle and frequency. A prototype circuit consisting of an H-bridge inverter, a transformer, two series resonant filters and two diode bridge circuits was constructed. The H-bridge inverter was connected to the primary side of the transformer and the diode bridge rectifier circuit was connected to the secondary side in parallel. Series resonant filters were inserted between one of the diode bridge circuits and the transformer. Thereafter, the proposed control method was applied to the transformer voltage of the prototype circuit. Although the circuit operation became complex owing to the circulating current flowing between the ground (GND) of the two output circuits, it exhibited ideal static and dynamic characteristics, thereby confirming the possibility of controlling two voltages with the duty cycle and frequency control factors. The results of the efficiency evaluation and loss analysis demonstrated a minimum efficiency of 68.3% and a maximum efficiency of 88.9%. As the output power of the circuit containing the resonant filters increased, the current peak value increased and the circuit became less efficient.

scholarly journals Optimization Technique Inspired Load Frequency Controller for Multi Area Power System with Renewable Energy Source

2021 ◽  
Vol 850 (1) ◽  
pp. 012017
Author(s):  
J Shri Saranyaa ◽  
A Peer Fathima ◽  
Asutosh Mishra ◽  
Rushali Ghosh ◽  
Shalmali Das
Keyword(s):  
Renewable Energy ◽  
Power Systems ◽  
Control Method ◽  
Frequency Control ◽  
Renewable Energy Sources ◽  
Optimization Technique ◽  
Optimization Method ◽  
Load Frequency Control ◽  
Load Frequency ◽  
The Individual

Abstract Modern day scenario has an increasing power demand due to the growing development which indeed increases the load on the generation which might cause turbulence in the system and may bounce out of stability. The governor itself can’t handle such frequent load changes and adjust the generation amount to keep the frequency between the margins. This paper proposes an approach towards such predicament to incorporate an optimization method in order to ensure stability of the system despite the drastic changes in demand. Load frequency control is a control method for maintaining the frequency of the system during the change in demand. Use of controllers has proven to be effective in controlling the frequency deviations in the power systems and the response of the controller is further improved using optimization technique for better stability. The PID controller tuned by Particle Swarm Optimization is employed in multi-area system which reduces the time response by a considerable amount and the deviation settles much quicker despite the rapid load changes. The proposed controller is executed further for renewable energy sources connected to the individual areas and demonstration proves that the optimized controller is efficient enough in handling the frequency deviations when wind and solar with sunlight penetration is incorporated.

A Decentralized Load Frequency Control Method by Means of Frequency Measurement of Adjacent Power Systems

1988 ◽  
Vol 21 (11) ◽  
pp. 387-393 ◽  
Author(s):  
H. Sasaki ◽  
H. Yorino ◽  
T. Suizu ◽  
S. Yurino ◽  
R. Yokoyama ◽  
...  
Keyword(s):  
Power Systems ◽  
Control Method ◽  
Frequency Control ◽  
Frequency Measurement ◽  
Load Frequency Control ◽  
Load Frequency

A Frequency Control Method by Wind Farm & Battery using Load Estimation in Isolated Power System

2010 ◽  
Vol 11 (2) ◽  
Author(s):  
Akie Uehara ◽  
Tomonobu Senjyu ◽  
Atsushi Yona ◽  
Toshihisa Funabashi
Keyword(s):  
Power Systems ◽  
Pitch Angle ◽  
Wind Farm ◽  
Control Method ◽  
Frequency Control ◽  
Wind Farms ◽  
Load Estimation ◽  
Small Power ◽  
Battery Energy Storage Systems ◽  
Battery Energy

Currently, there are several published reports on wind farms (WFs) for controlling output power by using pitch angle control. In addition, to reduce the adverse effects of frequency deviations, battery energy storage systems (BESSs) are introduced to small power systems. In this context, this paper presents a frequency control method by the WF and the BESS using load estimation. The load is estimated by a disturbance observer. The frequency deviations in low and high frequency domain are reduced by the WF using pitch angle control and battery charge/discharge, respectively. By using the proposed method, the reduction of the rated capacity of the BESS is possible. Furthermore, for the pitch angle control system of each WTG in the WF, generalized predictive control (GPC) is applied to achieve robust control performance. The effectiveness of the proposed method is verified by numerical simulation.

scholarly journals Dual-Active Bridge Series Resonant Electric Vehicle Charger: A Self-Tuning Method

Electronics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 253 ◽  
Author(s):  
Alireza Namadmalan ◽  
Kumars Rouzbehi ◽  
Juan Manuel Escaño ◽  
Carlos Bordons
Keyword(s):  
Control Method ◽  
Frequency Control ◽  
Fixed Time ◽  
Robust Solution ◽  
Zero Voltage Switching ◽  
Tuning Method ◽  
Dual Active Bridge ◽  
Series Resonant ◽  
Self Tuning ◽  
Power Direction

This paper presents a new self-tuning loop for a bidirectional dual-active bridge (DAB) series resonant converter (SRC). For different loading conditions, the two active bridges can be controlled with a minimum time displacement between them to assure zero voltage switching (ZVS) and minimum circulation current conditions. The tuning loop can instantly reverse the power direction with a fast dynamics. Moreover, the tuning loop is not sensitive to series resonant tank tolerances and deviations, which makes it a robust solution for power tuning of the SRCs. For simplicity, the power is controlled based on the power-frequency control method with a fixed time displacement between the active bridges. The main design criteria of the bidirectional SRC are the time displacement, operating frequency bandwidth, and the minimum and maximum power, which are simply derived and formulated based on the self-tuning loop’s parameters. Based on the parameters of the tuning loop, a simplified power equation and power control method is proposed for DAB-SRCs. The proposed control method is simulated in static and dynamic conditions for different loadings. The analysis and simulation results show the effectiveness of the new tuning method.

scholarly journals Analysis and Output Power Control of Unidirectional Secondary-Resonant Single-Active-Half-Bridge DC-DC Converter

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7432
Author(s):  
Cao Anh Tuan ◽  
Takaharu Takeshita
Keyword(s):  
Power Control ◽  
Output Power ◽  
High Frequency ◽  
Power Transmission ◽  
Control Method ◽  
Frequency Control ◽  
Input Power ◽  
Total Input ◽  
Bridge Circuits ◽  
Resonant Capacitor

Development of high-frequency-isolated DC-DC converters is underway for charging and discharging electric vehicle batteries. As a charger, a Single Active Bridge (SAB) converter, which is composed of a primary full-bridge converter, a high-frequency transformer, and a secondary full-bridge diode rectifier circuit, has been proposed as a unidirectional high frequency isolated DC-DC converter. In this paper, as a simple circuit configuration, a Secondary-Resonant Single-Active-Half-Bridge (SR-SAHB) converter, in which the primary and secondary circuits of the SAB converter are both half-bridge circuits, and a resonant capacitor connected in parallel to each secondary diode, is created. Due to the partial resonance on the secondary side, power transmission with unity transformer turn ratio and unity voltage conversion ratio can be realized, and a high total input power factor of the transformer can be achieved. As a result, the maximum voltage and current of the switching devices and the transformer voltage can be reduced. Moreover, soft switching in all commutations can be realized. The operation waveform is analyzed, and output power control is derived using the variable frequency control method. The effectiveness of the proposed SR-SAHB has been verified by experimental results using a 2.4 kW 20 kHz, 265V laboratory prototype.

Frequency control method based on the dynamic deloading of DFIGs for power systems with high-proportion wind energy

2021 ◽  
Vol 128 ◽  
pp. 106764
Author(s):  
Jinxin Ouyang ◽  
Mingyu Pang ◽  
Mengyang Li ◽  
Di Zheng ◽  
Ting Tang ◽  
...  
Keyword(s):  
Power Systems ◽  
Wind Energy ◽  
Control Method ◽  
Frequency Control

scholarly journals Dynamics of Momentary Reserves under Contingency: Observations from Numerical Experiments

2021 ◽  
Author(s):  
Kosisochukwu Pal Nnoli ◽  
Stefan Kettemann
Keyword(s):  
Power Systems ◽  
Reactive Power ◽  
Control Method ◽  
Frequency Control ◽  
Electrical Power ◽  
System Stability ◽  
Optimal Placement ◽  
Electrical Power Systems ◽  
Primary Frequency ◽  
Primary Frequency Control

This paper presents the studies and investigations on the dynamics of momentary reserves in electrical power systems under contingency. Momentarily reserve through the machine's inertia serves the purpose of primary frequency control and prevents voltage collapse in the case of reactive power reserves. A simulation was performed on a realistic Nigerian 330 kV transmission network in PowerFactory software to study and investigate the mechanism of these reserve functions on the network buses as an inertia active power control method. Moreover, we investigated the influence of geodesic increment of momentary reserve on the decay of disturbances. The results indicated that the momentary reserve by inertia alone reduces the frequency deviation from its nominal value, delays the transmission of disturbances and enhances the damping of oscillations by reducing the final frequency settling time at the buses under contingency. This numerical experiment also suggests the optimal placement of the momentary reserves in the grid in order to improve system stability against power outage disturbances.

scholarly journals Robust H∞ Load Frequency Control of Power Systems Considering Intermittent Characteristics of Demand-Side Resources

Electronics ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 593
Author(s):  
Kun Yuan ◽  
Zhetong Ding ◽  
Yaping Li ◽  
Mingyu Huang ◽  
Kaifeng Zhang
Keyword(s):  
Power Systems ◽  
Control Method ◽  
Frequency Control ◽  
Load Frequency Control ◽  
Linear Matrix ◽  
Intermittent Control ◽  
Demand Side ◽  
Load Frequency ◽  
The Stability ◽  
The Impact

Recently, demand-side resources (DSRs) have proceeded to participate in frequency control of the power systems. Compared with traditional generation-side resources, DSRs have unique intermittent characteristics. Taking aggregation of air conditions as an example, they must take a break after providing power support for a period of time considering the user comfort. This behavior, known as the intermittent characteristic, obviously affects the stability of the power systems. Therefore, this paper designs a corresponding controller for DSRs based on the intermittent control method. The designed controller is incorporated into the traditional load frequency control (LFC) system. The time delay is also considered. A rigorous stability proof and the robust H ∞ performance analysis is presented for the new LFC system. Then, the sufficient robust frequency stabilization result is presented in terms of linear matrix inequalities (LMIs). Finally, a two-area power system is provided to illustrate the obtained results. The results show that the designed intermittent controller can mitigate the impact of intermittent characteristics of DSRs.

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