PWM rectifier

About: PWM rectifier is a research topic. Over the lifetime, 2254 publications have been published within this topic receiving 25614 citations.

Development and Application of the Two-Phase Orthogonal Power Supply for Electromagnetic Stirring

Abstract: This paper presents a three-leg voltage-source inverter topology for two-phase orthogonal power supply used for driving electromagnetic stirring. Compared with the conventional two two-leg inverter, the three-leg structure reduced the loss of power module and switching. The improved structure has an inductor in series between two-phase orthogonal power supply and the common phase of electromagnetic stirring, which make it possible to apply deadbeat current control method to two-phase orthogonal power supply, thus the controller design is simplified, the current adjustment speed is enhanced, and the current waveform is improved. A control strategy with reactive power compensation is proposed for enhancing the utilization rate of a three-phase pulsewidth modulation (PWM) rectifier in two-phase power supply, which makes it possible that the three-phase PWM rectifier not only operating rectification status but also operating reactive power compensation status. Hence, the reactive compensation cost of enterprises will be decreased. At last, simulation and industrial application results are provided to verify the effectiveness of the proposed topology and control strategy.

Three-phase PWM rectifier control method based on deadbeat and triangular wave comparison

Abstract: The invention discloses a three-phase PWM rectifier control method based on deadbeat and triangular wave comparison, which belongs to the field of power electronic conversion technology and intelligent control. The control method of the invention mainly comprises steps of voltage outer loop, deadbeat control and triangular wave comparison control, wherein the voltage outer loop is a PI step; and the deadbeat control is current inner loop control. The control method is simple; and advantages of the triangular wave comparison control and the deadbeat control realize fixed frequency control with an input power factor 1, AC-side input current low harmonic and DC-side voltage stable tracking when switching frequency is low.

Motor Control Apparatus With Power Failure Determination Unit

Abstract: A motor control apparatus includes: a PWM rectifier; an inverter; a detection unit for detecting an AC voltage value of the PWM rectifier; a calculation unit for calculating a power supply voltage phase; a detection unit for detecting an AC current value of the PWM rectifier; a current loop control unit for generating an AC voltage command to control a power conversion operation of the PWM rectifier; a current loop saturation state determination unit for determining to be in a current loop saturation state when a magnitude of the AC voltage command is equal to or larger than a predetermined voltage prescribed value; an operation determination unit for determining whether the PWM rectifier is in a powering operation or in a regenerative operation and a power failure determination unit for determining a presence or absence of a power failure at the AC power supply side from the determination results.

Parameter independent encoderless control of servo drives without additional hardware components

Abstract: A lot of methods for sensorless drive control have been published last years for synchronous and asynchronous machines. One of the approaches uses high frequency carrier injection for position control. The injected high frequency signal is controlled to remain in alignment with the saliency produced by the saturation of the main flux. Due to the fact that it does not use the fundamental machine model which fails at standstill of the magnetic field it is possible to control the drive even at zero speed. In spite of this obvious advantage industry does not apply sensorless control in their products. This is due to the dependency of many published methods on physical parameters of the machine. The high frequency carrier injection method, presented in this paper, does not need to have exact machine parameters and it can be used for machines where there is only a very small rotor anisotropy like in Surface Mounted Permanent Magnet Synchronous Machines (SMPMSM) [1]. Standard drives usually are supplied by a 6-pulse diode rectifier. Due to new European directives concerning the harmonic content in the mains it is expected that the use of controlled pulse-width modulated PWM rectifiers will be enforced in the future [2]. An important advantage of this type of rectifiers is the regeneration of the energy back to the grid. Another benefit are low harmonics in comparison to diode rectifiers. Using one of many control methods published so far it is also possible to achieve almost unity power factor. However, in these methods voltage sensors are necessary to synchronize PWM rectifiers with the mains. Therefore they are not very popular in the industry with respect to the cost and the lack of reliability. Recently a control method was proposed which is based on a tracking scheme. It does not need any voltage sensor on the ac-side of the rectifier and it does not need to know accurate parameters of the system. This paper presents the control solution for a cheap, industry friendly (no additional hardware and installation effort) drive system. The phase tracking method for control of electrical drive and PWM rectifier is described. Encouraging experimental results are shown.

Novel Control Strategy of Instantaneous-Power Based Current-Source PWM Rectifier and Experimental Results

Abstract: This paper describes a novel direct-power-control startegy of a current-source PWM rectifier, and presents its experimentally examined operation characteristics. As shown in Fig. 1, the most important feature of this strategy is a direct selection of switching states of the PWM rectifier on the bases of instantaneous control errors of active and reactive power. This paper also describes a theoretical aspect on relationship between the instantaneous power and the switching states, which is essential to compose a switching-state table in the controller. Feasibility of the proposed strategy is verified through experimental tests, using a 2-kW prototype setup as well as computer simulations. Fig. 2 shows a power-source voltage, an input line current, a current PWM waveform, and DC bus current of the prototype. The input line current is sinusoidal and is in phase with the power-source voltage, which leads to a unity total power factor operation. Fig. 3 and Fig. 4 show total input power factor and total efficiency of the prototype, respectively. As can be seen, the maximum total input power factor of 99.86% and the maximum total efficiency of 92.72% have been confirmed in the tests as well as high-speed responses of the power. These results demonstrate feasibility and effectiveness of the proposed strategy.