The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The Switched Z-source Isolated Bidirectional DC-DC Converter (SZIBDC) is a novel topology that inherits the advantages of Dual Active Bridge (DAB) while overcoming its disadvantages. This paper presents the small-signal model of open-loop SZIBDC firstly. After that, five kinds of close-loop control strategies based on PI-regulator or Fuzzy Logic Controller (FLC) are theoretically analyzed and validated...
An improved PID sliding mode control strategy with constant switching frequency for the voltage regulator of doubly salient electro-magnetic generator has been proposed in this paper. Next, operating principle of controller was described in detail and the stable condition of the system was deduced by Lyapunov function based on mathematical model and working principle of generator. Considering improved...
In order to solve the design problem of coupled inductor in multiphase interleaving bidirectional DC/DC convertor, the universal design criterion of coupled inductor with general applicability was proposed. The Buck+Boost interleaving and magnetically integrated bidirectional DC/DC converter was studied under Buck mode with all inductors coupled symmetrically. The universal design criterion of coupled...
A fuzzy control strategy is presented to implement the neutral-point (NP) potential balance based on the power stage of three-level Boost dc-dc converter in this paper. The presented fuzzy controller can solve the imbalance problem of NP potential in the process of starting up and can suppress the influence of inverter circuit modulation strategy on NP potential. It is the fuzzy controller that can...
The design of PWM sliding mode control for a novel frequency conversion circuit which called boost matrix converter is presented. The general situation of sliding mode control strategy and frequency converters are firstly introduced. The specific analysis of boost matrix converter and the derivation process of PWM sliding mode controller are clarified afterwards. Finally the system simulation result...
In this paper, the mathematical model of the PMSM (permanent magnet synchronous motor) traction drive system is established. After the linearization of the model, the equation of state which takes the fluctuations of the DC traction voltage as input is deduced. Then the effects of the distance between the substation and the motor, the speed of the motor and the dc-link inductor on the PMSM traction...
This paper analyzes the error of digital control PFC system in the presence of digital signal processing, the control loop of PI, PID controller is equivalent to IIR digital filter, the mathematical statistics of errors by the control loop is calculated and the transfer model of noise in the system is gave. these works for the digital control PFC system to choose the right processor and reduce the...
According to the DC bias problem of AC power network, this paper puts forward the new type power transformer based on two-phase magnetic materials, which uses flux of two-phase magnetic materials to counteract flux of DC bias. In order to get variable stable flux of two-phase magnetic materials, intelligent control system is proposed with PWM controlled rectifier and detecting circuit of peak value...
This paper investigates the dynamic interactions of current controllers for multi-paralleled, grid-connected inverters. The consequent harmonics instability phenomena, which features with oscillations above the fundamental frequency, are evaluated by the impedance-based stability criterion. The frequency range of effective impedance-based stability analysis is first identified. The effect of each...
DC voltage control and power distribution are significant requirements for multi-terminal HVDC control system. The common voltage droop control has the drawback of failing to keep the dc voltage at a fixed value if active power is fluctuating, and voltage margin method actually controls dc voltage only by one converter at a time. A novel control strategy-Coordinated DC Voltage Control-is thus proposed...
The scale of a distributed grid-connected solar photovoltaic (PV) generation system keeps growing, which is naturally composed of many subsystems interacting with each other. In this paper, a novel distributed predictive control based on data-driven subspace approach is proposed to design the predictive controller of the grid-connected inverter in the distributed solar PV generation system. The control...
Delta compensated UPS can compensate ± 15% fluctuation of the grid voltage. In this condition, UPS supplies a stable sinusoidal voltage and maintains the input and out power balance by regulating the input current. The power balance is completed by cooperative work of the two converters, one converter operates in the rectifier state, and the other one operates in the inverter state, so that ensure...
Multiple resonances may result in instability of a LCL filter based multiple grid connected converter (MGCC) system. This paper investigates the critical factors of multiple resonances in MGCC system. It is found that, closed-loop output admittance of the grid connected converter can be configured to meet the requirements of resonances suppression, by properly designing control method and parameters...
DC microgrid will be the main power supply system for the future sustainable homes and buildings due to the advantages of the low converter cost and easy control with no reactive power concern. The system-level stability is an important issue in the design of the DC power supply system. The overlap between the output impedance of paralleled converter and load input impedance causes the system instability...
In order to reduce the harmonics in input currents effectively, this paper presents a double star rectifier with an auxiliary PWM rectifier at DC side. The volt-ampere rating of auxiliary PWM rectifier is only 10% of output power of the double star rectifier. The auxiliary PWM rectifier injects a particular triangular wave current into the secondary winding of inter-phase transformer to reduce the...
Voltage-controlled inverters are grid-friendly and can cope with the high penetration caused by connecting a lot of distributed generations. In low voltage power systems This paper proposes a simple and precise PQ control strategy based on improved voltage-controlled inverters with inner output impedance. The PLL part is replaced by second order generalized integrator method and it performs well when...
In this paper, a novel power electronic transformer (PET) structure for dc power distribution system is proposed. The proposed converter can achieve very high voltage conversion ratio with high frequency isolation and bidirectional energy flow, thus it can be used as the interface equipment of high voltage and low voltage dc power grid. Different from the conventional structure, only one high frequency...
Conventional model predictive current control (M-PCC) uses the discrete-time system model to select the best voltage vector by minimizing a cost function, which is related to the current errors. However, due to the limited number of voltage vectors in two-level converters, the sampling frequency has to be high to achieve satisfactory performance. To improve the steady state performance of conventional...
The DC current of the single-phase inverter or rectifier contains low frequency ripple whose frequency is twice that of the AC voltage. Traditionally, electrolytic capacitor is used to eliminate these ripple, but it has relatively short lifespan and affect the lifetime of the entire inverter or rectifier system. In this paper, a single-phase bidirectional bridge topology without electrolytic capacitor...
Distributed Power System (DPS) is a widely adopted power structure for renewable energy application and tele-communication, computer system, aerospace industry, etc. DPS is more reliable and flexible than the traditional concentrated power system. The communication for the DPS utilities plays an important role in the system framework. The reliability, low cost and easy implementation are important...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.