Capacitor Converter Research Articles

Capacitor voltage balancing, capacitance monitoring, and fast fault detection in a nested neutral point clamped (NNPC) converter with the reduced number of sensors

In multilevel converters (MCs), system components such as capacitors and semiconductor switches are very susceptible to damage. Furthermore, utilizing voltage sensors to balance capacitor voltages increases the system's cost and complexity while decreasing reliability. This paper presents methods for voltage balancing of capacitors, capacitance monitoring and open-circuit fault detection in nested neutral point-clamped (NNPC) converter with a reduced number of voltage and current sensors. In the proposed method, converter capacitors' voltage and current sensors are eliminated, and only the output sensors are employed to control the converter. In order to balance the voltage of capacitors, their voltages are estimated in three cases without using individual sensors. Comparing the capacitors' measured and estimated voltage change ratios is used to assess their health in the monitoring method. Thus, the capacitors' status can be checked by considering the system's health indicator during each period. Furthermore, the open-circuit fault detection method can identify defective switches within one processing cycle by comparing the converter's measured and standard output voltages in all switching states. The proposed methods have been evaluated in an experimental study of the system, and the results confirmed the effectiveness of the methods based on the new system configuration.© 2017 Elsevier Inc. All rights reserved.

An efficient implementation of three-level boost converter with capacitor voltage balancing for an advanced MPPT approach in PV Systems

Ensuring optimal extraction of power from photovoltaic (PV) systems under diverse climatic circumstances is a significant challenge, which requires an efficient Maximum Power Point (MPP) Tracking (MPPT) algorithm and an adequate conversion stage. Therefore, this paper proposes an advanced MPPT strategy implemented by a Three-Level Boost converter (TLB), which serves as the interface between the PV generator and the DC load, offering advantages such as reduced output voltage distortion, minimized inductor current ripple, and decreased switching losses. To achieve more accurate tracking, a robust voltage balance control across the TLB converter capacitors is also suggested. The proposed system is meticulously implemented and evaluated using MATLAB/Simulink, demonstrating its robust control capabilities in MPP tracking and voltage balancing across the TLB converter capacitors under diverse climatic scenarios. Furthermore, comparative analysis under various test circumstances including static and dynamic insolation conditions and sudden load variations, shows that the suggested MPPT algorithm offers noteworthy improvements over the InC algorithm. Additionally, a thorough comparison with existing research methods proves its effectiveness over these methods. The advanced MPPT strategy achieves a steady-state error of 0 W, an average tracking efficiency between 99.13 % and 99.44%, and fast-tracking velocity. Further, a comprehensive real-time evaluation using the cutting-edge RT-LAB platform confirms the consistency of the results with the simulation outputs, emphasizing the robustness and low implementation complexity of the overall proposed control strategy.

Converter Capacitor Temperature Estimation Based on Continued Training LSTM under Variable Load Conditions.

Capacitors are crucial components in power electronic converters, responsible for harmonic elimination, energy buffering, and voltage stabilization. However, they are also the most susceptible to damage due to their operational environment. Accurate temperature estimation of capacitors is essential for monitoring their condition and ensuring the reliability of the converter system. This paper presents a novel method for estimating the core temperature of capacitors using a long short-term memory (LSTM) algorithm. The approach incorporates a continued training mechanism to adapt to variable load conditions in converters. Experimental results demonstrate the proposed method's high accuracy and robustness, making it suitable for real-time capacitor temperature monitoring in practical applications.

Properties of ferroelectric composites in the microwave range

Ferroelectric ceramics of barium titanate and its solid solutions have found wide applications in technology, while compositions of a binary system with strontium titanate are most in demand. Electrically controlled components based on the barium titanate – strontium titanate ferroelectric ceramics are widely used in accelerator technology and the use of these materials is relevant at the present time. In the microwave range, composites based on the solid solution system barium titanate – strontium titanate ВаxSr1–xTiO3 (BST). Ferroelectric samples based on ВаxSrx–1TiO3 compound, where x = 0; 0.1; 0.3; 0.5; 0.7 were obtained using a conventional ceramic technology. The temperature dependences of the electrical properties of bulk ceramic samples based on ferroelectric composites were received in the temperature range 100°C to 350°C at a frequency of 1 kHz. It has been established that dielectric parameters significantly depend on the BaTiO3 content in BST compositions. To carry out a research in the frequency range from 0.1 to 8.5 GHz, an experimental setup was manufactured for measuring the electrical properties of ferroelectric materials based on an Agilent E5071C vector analyzer and a microstrip line. To conduct temperature studies, a microstrip line with a controlled sample was placed in a heat, cold and moisture chamber of the Bench-Top SU-261 series, in which it has been heated up to 60°C. The amplitude-frequency characteristics of the transmission coefficient (S21) of samples when heated from 20 °C to 60°C with an interval of 10 degrees were studied. The resonant frequency and quality factor of the resonator have been determined from the amplitude-frequency characteristic. Based on the value of the resonant frequency and the geometric dimensions of the sample, the dielectric constant of the sample material was calculated. It has been shown that with increasing barium titanate content (x = 0.1–0.3), the dielectric constant of the samples under study increases, and the resonant frequency shifts to lower frequencies. For samples with a barium titanate content of 50% and higher (x≥0.5), there are no resonance dependences and strong absorption of electromagnetic waves is observed. It has been established that with increasing temperature, the resonant frequency of composite material samples shifts to higher frequencies. Frequency dispersion of the dielectric constant is observed, which indicates the relaxor properties of the ceramic samples under study. Experimental investigations were carried out using a microwave strip line, a coaxial measuring cell and a capacitive converter; this made it possible to measure the dielectric constant of materials with values of more than several hundred in the microwave range and significantly reduce the control time when conducting thermal studies. It was shown that with a change in temperature, the electrophysical properties of the samples change significantly, which can be used in various systems and devices to change the reflection coefficient and phase of the electromagnetic wave.

An Intelligence-Based Controller for Improved Frequency Regulation in Deregulated Power Environment

A methodology for designing and assessing an optimal controller to regulate frequency in a two-area interconnected power system with Renewable Energy Sources (RES) is demonstrated in this paper. The Load Frequency Control (LFC) system makes it possible to restore both system frequency and scheduled tie-line power to their nominal values in a deregulated environment. The introduction of an advanced controller has the potential to improve the LFC mechanism's performance. The present article employs the Inertia Emulation Technique (IET) to demonstrate the potential influence of the novel High Voltage Direct Current (HVDC) tie-line model and converter capacitors. The Integral Time-weighted Absolute Error (ITAE) has been taken as an objective function for the proposed controller. This investigation proposes a novel adaptive control strategy i.e., ANN-based (PIλf + PIλDN) controller for the anticipated LFC mechanism. The modified Quasi-Opposition-learning-based Volleyball Premier League (QOVPL) method is utilized to assess the optimal control parameters with the highest efficacy. The effectiveness of the proposed LFC framework has been evaluated through the implementation of established methodologies for managing step and random load perturbations. The supremacy and effectiveness of the proposed control scheme are validated over recently published work.

Optimal selection of bulk capacitors in flyback converter

To optimize the selection of the bulk capacitor in a flyback converter, this paper proposes a method based on the lifetime and volume of aluminum electrolytic capacitors (Al e-caps). Firstly, mathematical models for the low-frequency and high-frequency harmonic currents of the bulk capacitor are established. The accuracy of these models has been verified by comparing the Saber simulation results and experimental results with calculated results, providing a basis for accurately calculating capacitor losses. Secondly, a lifetime model for the capacitor is established based on capacitor losses. The Pareto frontier of capacitor loss lifetime and volume is obtained using the multi-objective particle swarm optimization (MOPSO) algorithm, providing a basis for the optimal selection of the bulk capacitor. Finally, a 75 W flyback converter prototype is built based on the results obtained from the optimization process according to personalized requirements. The results show that the optimized capacitor has almost no effect on efficiency, and the volume decreases by 36.8 % with a sacrifice of 4.21 % in loss lifetime.

Optimal Heartbeat Energy Harvesting using Electrostatic Energy Harvesters

Microelectromechanical system of electrostatic energy harvesters is modeled using a nonlinear state–space approach in this research. The analytical models of in‐plane overlap, in‐plane gap closing, and their compound structures are used to analyze the energy harvesting performance from heartbeats‐generated vibrations. The detailed models of both electrical and mechanical subsystems including stopper function, motion drag, parasitic capacitors, and energy converter capacitors are developed in the format of state–space equations. To reach the optimal heartbeat energy harvesting, typical 1D harvesters are developed and allowed to move in x–y and x–y–z directions. Accordingly, the optimal harvester combines the features of in‐plane overlap and in‐plane gap closing energy conversions, and so allows efficient absorption of energy released by heartbeat in different directions. This 3D feature gives a considerable rise to power generation to 35.038 μw at the same size compared to the new rate of the in‐plane overlap or in‐plane gap‐closing electrostatic harvesters individually.

Design and implementation of a cost-efficient clamping capacitor boost converter for a hybrid renewable energy system for increased gain to fulfil demands

Power generation plants are built in rural areas to meet the power demands and empower the financial status. The existing method of electrical power generation is difficult to meet the growing population as they are turning to hybrid renewable energy systems to meet the increasing demand. They were also not focused on power saving and flow with reduced power loss. The power generated from hybrid renewable energy systems is distributed to rural areas through a DC-DC converter. The DC-DC converter converts the Hybrid Renewable Energy System (HRE) output into a high DC voltage transmitted in a bus. The proposed HRE system consists of solar and wind plants in the network. So, for transferring, saving, and utilizing the power generated from the hybrid renewable energy system, a cost-efficient clamping capacitor boost converter (CCBC) with increased voltage gain is proposed. The CCBC has a clamping capacitor in-built with 2-diodes and 2-capacitors. The voltage gain produced using the proposed CCBC is doubled with the conventional converters. There is no high range of power spikes in the converter's capacitor. This paper explains the architecture and the complete functionality of the CCBC with the simulation results in detail. The simulation results conclude that the proposed CCBC provides cost-efficient high voltage gain converters for HRE systems, providing more than 500 W, which fulfills the demand of a single rural area.

Advanced Fault-Detection Technique for DC-Link Aluminum Electrolytic Capacitors Based on a Random Forest Classifier

In recent years, significant technological advances have emerged in renewable power generation systems (RPGS), making them more economical and competitive. On the other hand, for the RPGS to achieve the highest level of performance possible, it is important to ensure the healthy operation of their main building blocks. Power electronic converters (PEC), which are one of the main building blocks of RPGS, have some vulnerable components, such as capacitors, which are responsible for more than a quarter of the failures in these converters. Therefore, it is of paramount importance that the design of fault diagnosis techniques (FDT) assess the capacitor’s state of health so that it is possible to implement predictive and preventive maintenance plans in order to reduce unexpected stoppage of these systems. One of the most commonly used capacitors in power converters is the aluminum electrolytic capacitor (AEC) whose aging manifests itself through an increase in its equivalent series resistance (ESR). Several advanced intelligent techniques have been proposed for assessing AEC health status, many of which require the use of a current sensor in the capacitor branch. However, the introduction of a current sensor in the capacitor branch imposes practical restrictions; in addition, it introduces unwanted resistive and inductive effects. This paper presents an FDT based on the random forest classifier (RFC), which triggers an alert mechanism when the DC-link AEC reaches its ESR threshold value. The great advantage of the proposed solution is that it is non-invasive; therefore, it is not necessary to introduce any sensor inside the converter. The validation of the proposed FDT will be carried out using several computer simulations carried out in Matlab/Simulink.

Fault identification scheme for protection and adaptive reclosing in a hybrid multi-terminal HVDC system

A fault identification scheme for protection and adaptive reclosing is proposed for a hybrid multi-terminal HVDC system to increase the reliability of fault isolation and reclosing. By analyzing the "zero passing" characteristic of current at the local end during the converter capacitor discharge stage, the fault identification scheme is proposed. The distributed parameter-based fault location equation, which incorporates fault distance and fault impedance, is developed with the injection signal and the distributed parameter model during the adaptive reclosing stage. The fault distance is determined using a trust region reflection algorithm to identify the permanent fault, and a fault identification scheme for adaptive reclosing is developed. Simulation results show that the proposed scheme is suitable for long-distance transmission lines with strong anti-fault impedance and anti-interference performance. Also, it is less affected by communication delay and DC boundary strength than existing methods.

An improved method to sub‐module voltage balancing in modular multilevel converters with two voltage sensors

SummaryThe modular multilevel converter (MMC) is an innovative structure that has expanded the usage of multilevel converters (MLCs) in the electrical industry. Since the MMC initially required a large number of sensors to manage the capacitor voltages, various studies have been done to reduce their number to improve the converter's reliability and reduce construction costs. In this paper's proposed method, merely two voltage sensors are used to balance the converter's capacitor voltages, and voltages are estimated using the exponentially weighted recursive least square (RLS) method in each sampling time. Also, the estimated voltages are sorted according to the capacitor current sign determined by the voltage sensors, and the current sensors are entirely eliminated. Furthermore, three cases for compensating the capacitor estimated voltages are presented, and the last case proposes the sub‐module force algorithm (SFA) for system protection. The efficacy of the proposed method has been assessed via simulation and experimental implementations.

Autonomous System for Energy Collection and Conversion Based on a Biofuel Cell

Functioning of a prototype of a micropower system (energy storage device) consisting of a biofuel cell (BFC) and converter–capacitor is demonstrated. The system allows conversion of a low input voltage from an unstable energy source to a standard working voltage used in radio equipment. For the series connection of two biofuel cells, the voltage is summed up and amounts to ~500 mV, and the output storage capacitor of 100 μF is charged in 13 min to a working voltage of 3.1 V upon a cold start of the converter. It is shown that energy storage substantially depends on the capacitance of the final storage unit and on the type of energy consumption. The proposed system can be used for different unstable energy sources.

Blackstart Capability of Modular Multilevel Converters From Partially-Rated Integrated Energy Storage

This paper discusses blackstart provision enabled by Modular Multilevel Converters (MMC) with integrated partially-rated Energy Storage (ES) systems. It is demonstrated that ES units integrated in an MMC for ancillary service provision can be utilised to energise the auxiliary power supply electronics of the submodules (SMs), fully charge the converter capacitors, and establish voltage at the ac and dc terminals. This feature can prove especially useful during the converter start-up phase in passive grids or following a post-fault disconnection event. For an MMC with integrated ES, the added functionality of charging the converter capacitors and starting-up the adjacent networks requires no additional infrastructure – only an updated control scheme. The charging algorithm goes through successive steps: ES-SM charging, <styled-content style="color:black" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">activation of the Auxiliary Power Supplies in the SMs</styled-content> , active charging of all SMs, <styled-content style="color:black" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">and finally,</styled-content> connection to the grid. The effectiveness of the method is confirmed by simulation results where a fully disconnected MMC charges nominally within 2 seconds, and connects to <styled-content style="color:black" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">a passive</styled-content> ac network. <styled-content style="color:black" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">By using a grid forming control scheme, the converter ramps up the voltage at the ac terminals and supplies 5% of active and reactive power with only 4% of ES-SMs per stack.</styled-content>

Electrical properties of the base film heterosystem Al/ITO/polyimide/Al2O3 for capacitive converter

On the basis of the conducted structural studies of thin films, a structural and technological solution was developed and a thin film capacitive transducer was created for acoustic monitoring of metal products by a capacitive method. It was determined that along with the crystalline structure of the layers, it is also necessary to control the surface electrical resistance of the conductive ITO layer, the values of which determine the possibility of using such a structure as a coating of a capacitive converter without significant losses of the useful signal, and the dielectric permeability of the Al2O3 layer, which significantly affects the value of the useful signal With the help of the four-probe method, it was established that the surface electrical resistance (R□) of ITO layers under optimal deposition conditions is equal to 8–15 Ohm/□. The study of electric power Hall results indicate that the obtained value of specific electrical resistance is determined by the concentration of the main charge carriers from about 8.3·1020 cm–3 and the mobility of the main charge carriers at the level of 44 cm2/(V·s). The results of studies of dielectric properties indicate an increase in the value of the dielectric constant of the polyimide/Al2O3 structure, which is 8.5–11.5 relative to units, relative to the polyimide film (3–3.9 relative units) by approximately 3 times at frequencies of the exciting signal in the range of 10 Hz–10 MHz. This fact confirms the assumption about the possibility of increasing the dielectric constant of the interlayer due to the application of a thin layer of Al2O3 on the polyimide film. To confirm the possibility of increasing the sensitivity of the method due to the use of a capacitive transducer based on the Al/ITO/polyimide/Al2O3 structure, in comparison with classical transducers, a series of aluminium samples was studied at an oscillation frequency of 2.5 MHz. The value of the received signal when using a thin-film converter increases by 7.6 times compared to a classic converter, which correlates well with the measurements of dielectric permeability of dielectric layers and taking into account the decrease in the thickness of the dielectric layer. Thus, the increase in the sensitivity of the capacitive method in the case of using thin-film capacitive converters based on the Al/ITO/polyimide/Al2O3 structure is experimentally confirmed. The maximum amplitude of the acoustic displacement occurs at the edge of the plate, so studies were conducted on electrodes with cutouts, which made it possible to increase the acoustic signal twice for a large internal cutout.

A fully dynamic third-order EF-CIFF noise-shaping SAR ADC with NTF zeros optimization and passive integration

In this paper, a third-order noise-shaping successive approximation register (NS-SAR) analog-to-digital converter (ADC) is proposed which is simple and fully dynamic. A passive integrator is utilized in the feed-forward (FF) path of a second-order NS-SAR ADC with 2nd-order error-feedback (EF) filter to reduce the effect of inband quantization and comparator noise. The integrator implements a passive gain of 4x to make up its loss arising from the charge sharing between the integrator and digital-to-analog converter capacitors at the integration phase. Another advantage of the proposed structure is employing a simple low noise and low power one-input pair comparator unlike many published NS-SAR ADCs which use a comparator with multi-input pairs leading to enhanced comparator input-referred noise and power consumption. In this work, the zeros of the noise transfer function are optimized to enhance inband noise suppression. The proposed ADC is designed at circuit level using 0.18 μm TSMC CMOS technology with Cadence Virtuoso tool. The oversampling ratio, sampling frequency, and bandwidth are 8, 2.5 MS/s, and 156.25 kHz, respectively. According to the detailed post-layout simulation results, the achieved signal-to-noise and distortion ratio of the simulated ADC is 83.1 dB with 70.3 µW power consumption from a 1.1 V supply.

Analysis of Capacitor Voltage Imbalance in Hybrid Converters and Inherently Balanced Operation Using Symmetric Architecture

This letter investigates the origin of the flying capacitor voltage imbalance in hybrid converters. An intuitive voltage–charge relationship is established to give a general explanation of the flying capacitor voltage balance in hybrid converters. The relationship is applied to devise a relatively simple and intuitive method to identify the behavior and performance difference of capacitor voltage and inductor current balancing performance in hybrid converters for <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$V_{\text{out}}&lt; \frac{V_{\text{in}}}{N}$</tex-math></inline-formula> cases. Conventional hybrid converters with an even number of inductor charging intervals are shown to be susceptible to flying capacitor voltage imbalance, while flying capacitors in hybrid converters with inductors having odd charging intervals have inherently balanced operations. As a direct result of the analysis, a new symmetric architecture and the operation of three-level buck converters are introduced to achieve an inherent balance of flying capacitor voltages, which can be applied to other flying capacitor multilevel converters. Hardware prototypes are implemented and measured for the verification of the analytical analysis and the new symmetric operation

Assessment of Amelioration in Frequency Regulation by deploying Novel Intelligent based Controller with Modified HVDC Tie-Line in Deregulated Environment

ABSTRACT This article emphasizes the design and analysis of an optimal intelligent controller for frequency regulation application. The load frequency control (LFC) mechanism is an eminent and essential mechanism to reinstate the system frequency and scheduled tie-line power to their nominal values. Employing an appropriate controller enhances the operation of the LFC mechanism. Hence, this article put forward an adoptive control policy-based fuzzy-fractional ordered PI controller parallel with fractional PIDN controller (i.e., Fuzzy (PIλf)+PIλDN) for the LFC mechanism. Besides that, a maiden attempt of using a new opposition-learning-based volleyball premier league (OVPL) algorithm is carried out to obtain optimal control parameters. The proposed optimal intelligent controller is explored for a nonlinear multi-area interconnected power system under deregulated environment. The proposed LFC scheme<apos;>s performance has been compared with several popular strategies for step and random perturb in load. Also, the robustness of the proposed scheme has been verified for a wide range of system parameter variations. On the other hand, the modified HVDC tie-line model and the impact of the inertia emulation technique (IET) using converter capacitors on transient behavior are illustrated in this article. Finally, the efficacy of the proposed LFC scheme has been verified over published literature on its platform.

Static DC Transformer Based on Negative Capacitance and High Voltage Engineering

Abstract: For DC voltage amplification, the operational amplifier is mostly used in the non-inverting configuration. In this case, the DC voltage amplification is done using a negative capacitance converter. Since the feedback capacitor acts as an open circuit for DC signal, it provides isolation between input and output. The amplified voltage level is limited by the breakdown voltage of the transistors used to build the op-amp and further the insulation breakdown limit of the Miller capacitor. By making use of new technologies such as silicon carbide technology, the breakdown voltage of transistors can be made higher even 1.2 KV and combined with high voltage engineering for capacitive insulation such as polymer capacitors, this can become a huge breakthrough in electric power engineering. Additionally, it can be used as a effective DC source for electric vehicles. The nominal voltage used in hybrid vehicles ranges from 100V to 200V.For electric-only vehicles, the required voltage is as high as 800V.The simulations are done using MIT Circuit sandbox, an open source circuit simulation tool. Keywords: DC amplifier, Op-amp, negative capacitance, silicon carbide and high voltage insulation.

SIMULATION OF COMMUTATION PROCESSES OF MULTI-LEVEL VOLTAGE INVERTER SWITCHES

An algorithm for controlling of commutator’s transistors of a single-phase multi-level voltage inverter is presented. The structure of the power circuit of the considered converter, in contrast to most existing circuits, does not depend on the levels number of the output curve due to the using of an universal source of levels, which are formed by output capacitors of two pulsed DC-converters. The commutator control algorithm ensures the formation of the required output curve of the inverter and excludes the occurrence of emergency situations during level commutating. Features of the converter and commutator operation in modes of active power transmission from pulse converters to the load and perception of the reactive power of the inverter load by them are considered.&#x0D; The commutator operation algorithm determines the sequence of control pulses, applied to the base of transistors, the sequence being synchronized with the process of the output voltage curve forming, as well as the direction of the inverter input current. At the same time, features of the level commutating are considered. They differ in the transition direction in value of level voltages: «up» from a lower value to a higher one and «down» from a higher value to a lower one. The sequence of supply and removal of pulses from control electrodes of switches and commutations caused by them, when the inverter input current is positive, are given. The similar commutating of levels is realized, when the inverter input current is negative. Wherein indexes of switches are rearranged in accordance with the direction replacement of their switching of the commutator circuit.&#x0D; A commutator model is realized using Micro-Cap 12 to demonstrate the operation of the algorithm. The transistor MJ15003 model is used as a commutator’s switch. In the model, output capacitors of pulse converters are represented by voltage sources, an autonomous inverter – by an active inductive load. The commutating from a higher voltage level to a lower one with a positive input current of the inverter is considered as an example. Simulation results confirm the performance of the algorithm.

Fuzzy and predictive control of a photovoltaic pumping system based on three-level boost converter

In this work, an efficient control scheme for a double stage pumping system is proposed. On the DC side, a three-level boost converter is employed to maximize the photovoltaic power and to step-up the DC-link voltage. For maximum power point tracking, the classical incremental conductance method is substituted by a fuzzy logic controller. The designed controller estimates the optimal step size which speeds up the tracking process and improves the accuracy of the extracted photovoltaic power. Afterwards, the voltages across the three-level boost converter (TLBC) capacitors are balanced by phase shifting the applied duty ratios. On the motor pump side, a two-level inverter drives the motor pump with the cascaded nonlinear predictive control. The predictive controller is preferred over the conventional field-oriented control because it accelerates the torque response and resists to the change of the engine parameters. The designed controllers are evaluated using MATLAB/Simulink, and compared with the conventional controllers (incremental conductance algorithm and field-oriented control). The robust control scheme of the entire system has increased the hydraulic power by up to 23% during the system start-up and up to 10% in steady state.