The dc bus capacitor selection should be based on the current handling capability but not the voltage ripple in a battery-powered inverter drive system. The conventional design using multiple bulky electrolytic capacitors can thus be completely replaced with a single high-current film capacitor.
Without the smoothing capacitor, C dc, the battery current I in equals the dc link current I dc, which is pulsating between 0 and the maximum load current. The figure indicates that the dc bus capacitor draws a current of I cap, which absorbs substantial high frequency current component from I dc, and thus smoothing out the input battery current.
Therefore, the dc bus capacitor, C dc, shown in Fig, 1 is needed to absorb the above-mentioned ripple current due to the inverter switching that has ±V dc applied to the motor windings so that the battery current is a smooth dc, and a longer battery life can be expected. The ripple current absorption burden, however, is apparently shifted to C dc.
The dc bus capacitor in high power traction motor drives need to deal with the following problems: (1) the ripple current due to inverter switching, (2) voltage fluctuation due to the source lead inductance, (3) voltage transient due to leakage inductance and fast device switching, and (4) over voltage due to regeneration.
The capacitor current varies with different load current conditions. Fig. 13 indicates the measured dc bus capacitor current versus input dc current. As a rule of thumb, in this induction machine based traction motor drive, the dc bus capacitor ripple rms current is approximately 61% of the input dc current.
Conventional inverter design sizing dc-bus capacitor based on voltage ripple is no-longer effective. In order to handle high current in high temperature environment, a low- inductance high-current film capacitor is proposed to replace the conventional electrolytic bulk capacitors for a 75-kW traction motor drive inverter.
Using capacitors is one of the most efficient methods in reducing system ... the PSO algorithm [1-2]is used to achieve the optimal size of capacitors to reduce the cost of losses as well as the …
• Design optimized to reduce bus inductance and voltage overshoot • Annular shape provides very short path between electrodes and therefore very low ESR (0.2 – 0.5mΩ) – High speed …
requirements and challenges. The DC-link capacitor selection is one of the first and most important steps. It not only dictates the bus bar complexity but also is the key to accomplish a …
With a successful development of using a newly developed low-inductance high-current film capacitor in a high power (75 kW) traction motor drive, the intention of this paper is to provide …
Three methods are proposed to reduce the capacitance of the bus, and the mathematical relationship between the maximum value of the DC link current and the minimum capacitance …
Three methods are proposed to reduce the capacitance of the bus, and the mathematical relationship between the maximum value of the DC link current and the minimum capacitance …
Without using sensor, the load current is estimated from the calculated DAB''s output bridge current and lossless sensing (with digital filter) of the dc-bus capacitor current. The effects of any non-idealities on load current …
In order to reduce the ripple current and smooth the external voltage on batteries and fuel cells, a bulky capacitor or ultracapacitor is often connected in parallel with them to
Reduction of DC Bus Capacitor Ripple Current with PAM/PWM Converter Frederick D. Kieferndorf, Matthias Förster and Thomas A. Lipo University of Wisconsin-Madison Dept. …
In order to reduce the electrolytic capacitors on the DC Bus side and limit the short-circuit current under inter-pole short-circuit conditions, this paper proposes the …
Once a design has been optimized to reduce bus inductance and voltage overshoot, it is important to understand how the capacitor temperature will limit system performance. The …
Abstract—Bulky electrolytic capacitors, which are often needed in DC systems to filter out voltage ripples, considerably reduce power density and system reliability.
In this paper, a method to reduce the ripple current in a constant Volts/Hertz pulse-amplitude-modulation (PAM)/pulsewidth-modulation (PWM) converter driving an induction motor is …
Abstract—Bulky electrolytic capacitors, which are often needed in DC systems to filter out voltage ripples, considerably reduce power density and system reliability.
Reduce Inrush Current Using Load Switches Aleksandras_Kaknevicius In most systems, capacitors are placed throughout a design to ensure there are no supply-rail voltage drops. …
Once a design has been optimized to reduce bus inductance and voltage overshoot, it is important to understand how the capacitor temperature will limit system performance. The …
This way, we can use k as the relative permittivity of our dielectric material times the permittivity of space, which is 8.854E-12 F/m. Note that k = 1 for air.. So the area of the plates and the …
Most Permanent Magnet (PM) motors have power factors in the range of 0.70 - 0.95 so you can see from the plot above that maximum capacitor current in this power factor …
In this paper, a single-phase PWM-controlled rectifier is taken as an example to analyse the ripple energy that causes the voltage ripples on the DC bus. Moreover, a ripple-current compensator …
The study involves the deployment of 3.42MVAr capacitor banks in 20kV, 4-bus-bar systems and 1.164MVar capacitor banks in 0.4kV, 2-bus-bar systems. The impact is thoroughly ... Also the …
what extent the capacitor ripple current can be reduced through the use of an interleaved PFC boost converter. A fast calculation method has been proposed [4] to calcu-
Fig. 7 shows the voltage and current waveforms of the capacitor on bus A2 during the energization of SCB on A2, when the SCBs of the buses A1 and A3 are in-service. The …