Proposed Parameter Design Method Research Articles

An optimal parameter design method for cascaded H‐bridge multi‐level converter in wind farm

AbstractThe cascaded H‐bridge multi‐level converter is the main topology of high‐voltage and high‐capacity converter in renewable energy power generation, energy storage system and reactive power compensation equipment. The parameter design of cascaded H‐bridge multi‐level converters directly determines the material cost and performance. Taking the output current distortion rate and the ripple voltage of the capacitor of the cascaded H‐bridge multi‐level converter as the constraint conditions, this paper proposes an overall parameter optimal design method of the cascaded H‐bridge multi‐level converter based on the optimization of the total material cost. Finally, the effectiveness of the proposed parameter design method is verified by the simulation result.

Rectifier load modeling and zero voltage switching design of inductive power transfer system with S‐type topology on the secondary side

SummaryRectifier load in inductive power transfer system has nonlinear characteristics. However, the traditional analysis method equates it to a pure resistor, which leads to a certain deviation between the theoretical analysis and the actual circuit. This will reduce the accuracy of the inductive power transfer (IPT) system model and affect the soft switching operation of the inverter. In this paper, the IPT system with S‐type topology on the secondary side is studied. Firstly, the resistance–inductance characteristics of the rectifier load are analyzed by simulation, and then a second‐order circuit response model is established to solve the time‐domain expression of voltage and current. Then, the fundamental component of voltage and current is extracted by Fourier transform to calculate the impedance value of the rectifier load, and the mathematical calculation model of the rectifier load is established. On this basis, the influence of the inductive component of the rectifier load on the input impedance of the IPT system is analyzed. Then, a parameter design method for zero voltage switching is proposed for S‐S and LCC‐S topologies. Finally, an experimental platform of S‐S and LCC‐S IPT system is built. The correctness and effectiveness of the theoretical analysis and the proposed parameter design method are verified by experiments.

Current Stress Optimization for Double-Sided CLLLC Topology-Based IPT System With Constant Output Current Tolerating Pad Misalignments

In the inductive power transfer (IPT) system, a hybrid topology with the anti-misalignment ability and load-independent output is usually used to improve the stability of the system and simplify the control scheme. However, the power distribution of the hybrid topology is uneven with misalignment, resulting in high current stresses in partial coils. In order to minimize the current stresses, a parameter design method with double-sided capacitor-inductor-inductor-inductor-capacitor compensation topology is proposed to optimize the coil currents without the effect on the output fluctuation. Finally, a 3.5-kW laboratory-scale prototype was built to validate the proposed method. The results show that the proposed parameter design method can minimize the maximum current stress significantly, and the hybrid IPT system has good performances of misalignment tolerance and load-independent output current.

A CPT system with switchable compensation for constant current or voltage output against load and coupling capacitance variations

This paper proposes a novel capacitive power transfer (CPT) system with switchable compensation for achieving constant current (CC) or constant voltage (CV) output against load and coupling capacitance variations. Meanwhile, a parameter design method is proposed to ensure a low input impedance angle at constant operation modes. Mathematical models of voltage and current gains are established, which are used to analyze the CC and CV operation modes of the proposed CPT system. Two relays are adopted in receiver to reconfigure the compensation network to switch the CC mode and CV mode. The communication between the transmitter and receiver is not needed, and complex control is not required either for changing two operation modes. An experimental setup with 2A output current in CC mode and 96 V output voltage in CV mode is constructed. Experimental results show that the maximum variation of the output current is 4.0% in CC mode, and the maximum variation of the output voltage is 5.0% in CV mode, when the load resistance and coupling capacitance vary from 24 to 72 ohms, and 500 to 1000 pF, respectively. Experimental results verify the CC/CV output and the effectiveness of the proposed parameter design method.

Parameter Design Method With Constant Output Voltage Characteristic for Bilateral LC-Compensated CPT System

In order to solve the problem that the output voltage of bilateral LC -compensated capacitive power transfer (CPT) system varies with the variation of load and equivalent coupling capacitance, this article presented a parameter design method that maintained the output voltage constant and guaranteed a high power factor. The mathematical model of the bilateral LC -compensated CPT system was established. The characteristic of the primary and secondary LC -compensated network was analyzed, and then, the conditions remaining a constant output voltage with varying load and coupling capacitance were determined. The relationship between the power factor and the load versus equivalent coupling capacitance was given. With the proposed parameter design method, a 100-W bilateral LC -compensated CPT experimental setup was constructed. The output voltage changes from 55.0 to 58.7 V and the power factor varies from 0.902 to 0.977 when the load and coupling capacitance vary from 30.2 to $70.8~\Omega $ and from 310 to 1490 pF , respectively. Both the simulation and experimental results have verified the characteristic of constant output voltage and the effectiveness of the proposed parameter design method.

Principle and Robust Impedance-Based Design of Grid-tied Inverter with LLCL-Filter under Wide Variation of Grid-Reactance

Currently, how the inductive grid impedance variation affects the stability of digitally controlled grid-tied inverters with a high-order ( LCL or LLCL ) filter has been numerously studied. Note that a distributed power system may contain the capacitive load, the power factor correction (PFC) capacitor, and the long cable. During the design of grid-tied inverters, we should address the effects of the equivalent grid reactance, including both the inductive and the capacitive impedances, on the stability of system. Nevertheless, up to now, to the best knowledge of authors, the detailed parameter design method of the LCL - or LLCL -filter-based grid-tied inverter has not yet been introduced, when the capacitive grid impedance is addressed. In this paper, by using the passivity-based analysis, the detailed stability study on the LLCL -filter-based grid-tied inverter is carried out, when the grid reactance varies in a wide range. Based on the analysis, an exact and robust parameter design of system is proposed. Simulations and experimental results on a 220 V/2 kW prototype confirm that by using the proposed parameter design method, a high-performance grid-tied inverter system can be achieved under the rigid grid condition.

Design and parametric study on energy harvesting from bridge vibration using tuned dual-mass damper systems

A bridge vibration energy harvester has been proposed in this paper using a tuned dual-mass damper system, named hereafter Tuned Mass Generator (TMG). A linear electromagnetic transducer has been applied to harvest and make use of the unused reserve of energy the aforementioned damper system absorbs. The benefits of using dual-mass systems over single-mass systems for power generation have been clarified according to the theory of vibrations. TMG parameters have been determined considering multi-domain parameters, and TMG has been tuned using a newly proposed parameter design method. Theoretical analysis results have shown that for effective energy harvesting, it is essential that TMG has robustness against uncertainties in bridge vibrations and tuning errors, and the proposed parameter design method for TMG has demonstrated this feature.

An <italic>LCL</italic>-<italic>LC</italic> Filter for Grid-Connected Converter: Topology, Parameter, and Analysis

In order to further cut down the cost of filter for grid-connected pulsewidth modulation (PWM) converter under the more and more stringent grid code, a new kind of high-order filter, named LCL - LC filter, is presented in this paper. The resonant frequency characteristics of the filter are analyzed, and a parameter design method on the base of the characteristics is also proposed in the paper. The proposed parameter design method can easily make full use of the existing research results about the traditional LCL filter parameter design. And then a parameter robustness analysis method based on four-dimensional graphics is proposed to analyze parameter robustness of the presented filter. Compared with the traditional one, the proposed analysis method can analyze the filter performance under variations of several parameters at a time without any iteration. The comparative analysis and discussion considering the LCL filter, the trap filter, and the LCL - LC filter, are presented and verified through the experiments on a 5 kW grid-connected converter prototype. Experiment results demonstrate the accuracy of theoretical analysis and prove that the presented filter has a better performance than two others.

Parameter Design of a Three-Level Converter Based on Series-Connected HV-IGBTs

Although the maximum collector-emitter voltage of a high-voltage insulated-gate bipolar transistor (HV-IGBT) reaches 3300 V or higher, it still cannot satisfy the requirements of some high-voltage high-power converters. Applying power semiconductor devices in series connection can effectively improve the voltage rating and power rating of a power electronic converter. The key issue of device series connection is voltage balancing in static switching state and dynamic switching state. In this paper, a three-level converter based on series-connected HV-IGBTs is presented, its voltage-balancing subcircuits are analyzed, and the parameter design method for the converter is proposed. During the design process, key performance indexes of the series connection circuit, such as the voltage-balancing effect, loss of the voltage-balancing circuit, switching loss, and switching time, are comprehensively considered. Moreover, component parameters of the three-level converter are calculated considering the influence of the voltage-balancing circuit. The proposed parameter design method is applied in the development of a three-level HV-IGBT (4500 V/600 A) series connection test platform with 10 000-V rated dc-link voltage. Experimental results verify the validity of the proposed method.

Simulation and Parameter Design of a 10kw Wireless Power Transfer System Applied to Gantry Crane

Gantry cranes are used throughout the materials handling industry. But conventional methods of power transfer to the cranes such as trolley conductor and wire directly connected have remained less than ideal, that is until the recent development of a novel wireless power transfer (WPT) system that is clean and spark-free, is robust to dust and water, and has very low maintenance. A 10kw WPT simulation system applied to gantry crane has been developed. The best compensation topology and the parameter have been studied in order to get high efficiency of the system. The study has been focused in showing the parameter design. Finally, the simulation has proved the validation of the proposed parameter design method.

Accurate parameter design for radial AC hybrid magnetic bearing

For more stable operation of radial AC hybrid magnetic bearing (radial AC HMB), it is particularly important to realize optimization design of parameters for its prototype. The paper focuses on solving the several typical defects of traditional methods and puts forward specific countermeasures on improving its disadvantages. Thus, a new parameter design method based on two sets of magnetic field system (the stator core magnetic field system and the air gap field system) is proposed to calculate the structure and electromagnetism parameters of the radial AC HMB. Using the proposed parameter design method, a finite element model of radial AC HMB based on the design results are simulated in finite element analysis software. The simulation results are consistent with the expected parameters calculation results very well, which show accuracy of the parameters and the proposed method. To illustrate the validity of the parameter design approaches further, the verification experiment is conducted. The operating experimental results show that the radial AC HMB has high stability, fast start of suspension and fine anti-disturbance. Moreover, system performance comparison results show the control system based on the new parameter design method has stronger anti-disturbance characteristics than that based on the traditional parameter design method.