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The power converter with an unstable input high voltage (2000...4000 V DC) and stable output three-phase voltage 380 V, 50 Hz AC is presented. Various converter types with high frequency principle and 50 Hz principle of the electrical energy transformation are investigated. The main emphasis is given to the analysis procedure of power losses in semiconductors devices. Basis equations of power losses...
A kind of recurrent fuzzy wavelet neural network (RFWNN) is constructed by using recurrent wavelet neural network (RWNN) to realize fuzzy inference. In the network, temporal relations are embedded in the network by adding feedback connections on the first layer of the network, and wavelet basis function is used as fuzzy membership function. An adaptive control scheme based on RFWNN is proposed, in...
The power active filter (APF) is used to suppress the harmonics and compensate the reactive power which are produced by the nonlinear loads. The traditional method of the sinusoidal current synthesis (SCS) would deteriorate the distortion level in the common coupling, thus result in the harmonic propagation through the power distribution system. The method of the resistive load synthesis (RLS) can...
In this paper, a 2 kW PFC active IPEM (integrated power electronics modules) employing CoolMOS and SiC diode is developed. The thermal model of IPEM is developed and the power dissipation of every power devices in the active IPEM is calculated through the measurement-based power loss graph in datasheet. With the requirements of uniform temperature distribution and slight thermal interaction between...
This paper extends the limit-trajectory two-mode overmodulation ideal into single mode. The harmonic characteristics of them are analyzed and compared. Based on one TI TMS320LF 2407A DSP, the proposed method is verified with an open-loop V/F controlled diode-clamped three-level model inverter. With the test result, it is confirmed that single-mode limit-trajectory overmodulation technology is correct...
A novel circuit configuration to compensate for the reactive power is proposed in this paper. This hybrid reactive power compensator includes an AC capacitor set serially connected to a small-capacity power converter. The AC capacitor set can avoid the damage caused by the power resonance and harmonic current injection after using this hybrid reactive power compensator. Because the AC capacitor set...
A small single-phase fuel cell based energy generation and compensation system is proposed in this paper. The power conditioning unit of the system comprises a grid-interfacing inverter and a three-port bidirectional converter which connects a fuel cell and supercapacitor to the inverter. The system can operate in both island and grid-connected modes. By taking advantage of the transient storage capability...
In this paper, a three-phase active power filter based on space vector and one-cycle control was proposed. According to the ideal of space vector, the three-phase voltage is divided to six regions. In each region, the model of one-cycle control is established. The proposed control method has some advantages, such as it only needs to detect the three-phase electrical power's voltage, current, neutral...
Based on the p-q-r theory, this paper presents a direct control strategy of unified power quality conditioner (UPQC) used in the nonlinear and unbalance three-phase four-wire system. A algorithm of calculating the series compensation current and shunt compensation voltage in the proposed system is introduced. An analysis of the proposed control strategy and its schematic diagram is described in particular...
A dynamic voltage restorer is a power quality (custom power) device used to correct the voltage disturbances by injecting voltage as well as power into the system. The compensation capability of a dynamic voltage restorer (DVR) depends primarily on the maximum voltage injection ability and the amount of stored energy available within the restorer. In this paper a simple structure feed forward neural...
This 230 kA DC power source is composed of four set separated DC power in parallel operation. There are +3.75deg, -3.75deg, +11.25deg, -11.25deg phase shifting between each rectifier transformer and original source. Each set device mainly contains on-load tap changer, phase-shifting rectifier transformer and con-phase counter parallel rectifier. In this paper, a current control scheme is realized...
In this paper, DC-DC converters are viewed as one class of hybrid systems i.e. switched linear systems. A new mathematical model of switched linear systems-matrix coefficient polynomial description model is presented. An obvious description form of the relationship between the continuous variable and discrete variable is built, a new model of switched linear system of DC-DC converters, in which continuous...
Based on the mathematical model of flyback switching DC-DC converter in the continuous current mode and the simulation model under heavy loads, this paper presents a study of the steady-state power loss in the output diode, including the loss calculation models under three operational modes (voltage control, under-voltage, and over-current modes), the relations of the diode loss versus the input and...
High power DC/DC converter has become the essential part of the distributed power system in fuel cell powered electric vehicles and stationary power systems. This paper proposes a topology of high power dual-phase boost DC/DC converter for fuel cell power supply. The principle of the converter operating in BOOST mode are analyzed thoroughly. A 150 KW converter was designed. The converter was adopted...
Allowing a significant reduction of capacitor volumes as well as scalable in terms of voltage levels and control flexibility, stacked flying capacitor inverter has gained great industrial attention recently. However, it also needs to ensure balancing flying capacitor voltages under all operation conditions. A novel PWM method is proposed for stacked flying capacitor multilevel inverter to control...
In this paper, an approach by using the Agilent 4395A to measure the loop gain of the power supply has been deeply developed. The main issues have been investigated as the following: (1). Measurement techniques about the parasitic parameters of the filtering components will be studied. One is how to test of the electrolyte capacitor by Agilent 4395A; another is how to test dynamic inductance of filter...
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