Power Losses In Inverter Research Articles

The Impact of Output Voltage Modulation Strategies on Power Losses in Inverter

The technique and results of investigation of power losses in inverter obtained for case when proposed Space Vector Pulse Frequency Modulation (SVPFM) method with averaged pulse lengths is employed for forming of three-phase inverter output voltage are presented in the work. The obtained results were compared with the results gained for conventional SVPFM method. It is shown that employment of the suggested modification of the SVPFM method allows decreasing the power losses in inverter, which is used in frequency converter for AC induction motor control, as compared to the case when conventional SVPFM method is employed. It is stated that reduction of power losses is caused by introduction of the switch commutation algorithm, which enables to minimize the number of switching of inverter switches and avoid commutations at maximal current. Additional reduction of the power losses is achieved by use of averaged pulse lengths, which allow improving the initial part of voltage spectrum. Ill. 7, bibl. 7 (in English; summaries in English, Russian and Lithuanian).

Electron Irradiation Lifetime Control for SiC Bipolar Devices of 200 kVA High Power SiC Inverters

To reduce the switching power losses of SiC bipolar devices, an electron irradiation lifetime control method was investigated and was successfully applied to the development of 200kVA full SiC inverters, in which SiCGTs and SiC pn diodes irradiated electrons were used at the condition required to minimize inverter power loss.

Three-level voltage-source inverter for shunt active filter

An active power filter or power-line conditioner is an important way to compensate reactive power and suppress harmonics drawn from nonlinear loads. A single-phase active filter is presented to operate as a controlled current source to compensate the load harmonics and generate a sinusoidal line current from the AC source. The adopted single-phase voltage-source inverter is based on four active switches and two capacitors to achieve three-level pulsewith modulation. The circuit topology of the adopted inverter has fewer power semiconductors compared with the single-phase neutral-point-clamped inverter and flying capacitor inverter. To maintain the DC-link voltage constant and compensate the power losses of inverter, a proportional-integral voltage controller is used in the outer control loop. A carrier-based current controller is adopted in the inner control loop to track the line current command in phase with the mains voltage. The effectiveness of the proposed control algorithm is verified by computer simulation and experimental results.

An eight-switch three-phase VSI for power factor regulated shunt active filter

A three-phase neutral point clamped (NPC) inverter operated as a shunt ac line conditioner is presented. Eight power switches and four clamping diodes with voltage rating vdc/2 are used in the proposed inverter. The presented inverter can compensate current harmonics and reactive power generated from the nonlinear loads, and supply the demanded dc side power of the inverter. If there is no nonlinear load connected to the system, the adopted inverter is operated as a power factor pre-regulator. If there is no output load connected to the dc side of the inverter, the inverter is operated as a shunt active filter. If a nonlinear load is connected to the ac source and a dc load is connected to the inverter, the adopted inverter is operated as an integrated power quality compensator to draw the sinusoidal line currents from the ac mains. To supply the necessary active power for the dc side load and compensate the power losses of inverter, a proportional-integral (PI) controller is used to obtain the active power for the inverter. A space vector pulse-width modulation (SVPWM) is used to track the line current commands. Simulation and experimental results based on a laboratory scale-down prototype are presented to verify the effectiveness of the proposed control scheme.

Power losses in PWM-VSI inverter using NPT or PT IGBT devices

This paper investigates the power losses for two different IGBT technologies (nonpunch through and punch through) for use in PWM-VSI inverters in order to choose the right device technology for a given application. A loss model of the inverter is developed based on experimental determination of the power losses. The loss model is used on two different modulation strategies which are a sine wave with a third harmonic added and a 60/spl deg/-PWM modulation where only two inverter legs are active at the same time. The two IGBT technologies are characterized on an advanced measurement system which is described. The total power losses in the inverter are estimated by simulation at different conditions and it is concluded that the nonpunch through (NPT) technology is most useful for higher switching frequencies, while the punch through (PT) technology is especially useful at lower switching frequencies and high load currents. It is also concluded that the 60/spl deg/-PWM modulation has the lowest power losses and the power losses are almost independent of phase angle cos(/spl phi/) for normal motor operation.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

An Evaluation Method of Power Loss in Resonant DC Link Inverters.

Resonant DC link inverters, which can realize high switching frequency power conversion without switching loss in principle, have been proposed and investigated. In such inverters, power loss is produced in the resonant circuit though power loss in the main circuit is reduced by the amount of the switching loss Therefore, an evaluation method of the total power loss should be established from the view point of efficiency.In this paper, first we summarize the circuit operation and the control method of the resonant DC link inverter. Based on this, the expressions for various power losses produced both in the inverter main circuit and in the resonant circuit are derived. In this derivation, since the turn-on signal for an inverter arm is assumed to be determined only by comparison of the actual output current and its reference, a concept of probability is introduced for the turn-on signal of each inverter arm.As an investigation of the resonant reactor, which affects the total power loss significantly, two types of reactor are constructed and the frequency characteristics of their resistances are clarified experimentally.To confirm the validity of the expressions for losses derived in this paper, a comparison of the calculated and measured total losses is made for an experimental system.