Class B Amplifiers
... view of the cutoff region. We bias the transistor at soft cutoff to avoid crossover distortion. At soft cutoff, there is still a small amount of collector current flowing • If we bias the transistor at hard cutoff, we will eliminate most of the collector current but we introduce crossover distortion ...
... view of the cutoff region. We bias the transistor at soft cutoff to avoid crossover distortion. At soft cutoff, there is still a small amount of collector current flowing • If we bias the transistor at hard cutoff, we will eliminate most of the collector current but we introduce crossover distortion ...
Comparison of the AC UPS and the DC UPS solutions for critical loads
... may easily be replaced with standard switch mode converters which are readily available. The investigations at Netpower Labs show that almost all PCs, displays and workstations with 230 VAC rated power supplies, both laptops and ATX form factor, work fine when supplied directly from a 350 VDC source ...
... may easily be replaced with standard switch mode converters which are readily available. The investigations at Netpower Labs show that almost all PCs, displays and workstations with 230 VAC rated power supplies, both laptops and ATX form factor, work fine when supplied directly from a 350 VDC source ...
MODELS OF EXCITATION SYSTEMS
... identical, independent excitation channels. Only one of these channels operates at the time and covers all operating regimes of the generator, including field forcing; the other is a backup channel. Each channel contains digital controller of the exciter and the thyristor bridge. ...
... identical, independent excitation channels. Only one of these channels operates at the time and covers all operating regimes of the generator, including field forcing; the other is a backup channel. Each channel contains digital controller of the exciter and the thyristor bridge. ...
User Manual VME64x 7U
... Automatic daisy chaining works without jumpers, i. e. the user does not need to bother with plugging in and removing jumpers. CHASSIS GND connection There is a solid electrically conductive chassis GND surface in the backplane- to-card rack mounting area. This guarantees EMC-tight mounting of the bu ...
... Automatic daisy chaining works without jumpers, i. e. the user does not need to bother with plugging in and removing jumpers. CHASSIS GND connection There is a solid electrically conductive chassis GND surface in the backplane- to-card rack mounting area. This guarantees EMC-tight mounting of the bu ...
The unified power quality conditioner: the integration of series and
... When no series-active filter is connected (AF off), the supply harmonic voltage at 240 Hz is amplified by about ten times at and the load terminal because of series resonance between . After the series-active filter based on either the currentdetecting method or the combined method is operated, no t ...
... When no series-active filter is connected (AF off), the supply harmonic voltage at 240 Hz is amplified by about ten times at and the load terminal because of series resonance between . After the series-active filter based on either the currentdetecting method or the combined method is operated, no t ...
Aalborg Universitet Advanced Control Architectures for Intelligent Microgrids—Part II
... based on using shunt active power filter for voltage unbalance compensation [6]. In these works, voltage unbalances caused by unbalanced loads are compensated by injecting negative sequence currents. In addition, when the voltage is highly unbalanced and distorted, a big amount current is needed, th ...
... based on using shunt active power filter for voltage unbalance compensation [6]. In these works, voltage unbalances caused by unbalanced loads are compensated by injecting negative sequence currents. In addition, when the voltage is highly unbalanced and distorted, a big amount current is needed, th ...
IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
... Power electronic systems that are connected to the grid have to fulfill EMI standards concerning the level of DM EMI noise in the grid-side current, as e.g. Class A and Class B limits from CISPR. In order to meet such regulations, mains-connected boost power factor correction (PFC) circuits are empl ...
... Power electronic systems that are connected to the grid have to fulfill EMI standards concerning the level of DM EMI noise in the grid-side current, as e.g. Class A and Class B limits from CISPR. In order to meet such regulations, mains-connected boost power factor correction (PFC) circuits are empl ...
Power-generation, Power-electronics and Power
... concerns for the users today. The contribution from this project concerns mainly power electronic issues as a suggested switching strategy and the combination of bipolar and unipolar switching of a single-phase inverter. In the second part the research focused on power-system issues. These are not a ...
... concerns for the users today. The contribution from this project concerns mainly power electronic issues as a suggested switching strategy and the combination of bipolar and unipolar switching of a single-phase inverter. In the second part the research focused on power-system issues. These are not a ...
Lesson: 23
... If terminal 3 is +ve then we find that secondary will drive current through the load leaving from terminal 3 and entering through terminal 4. Therefore flux produced by the secondary clearly opposes the primary flux fulfilling the condition set by Lenz’s law. Thus when terminal 1 is +ve terminal 3 o ...
... If terminal 3 is +ve then we find that secondary will drive current through the load leaving from terminal 3 and entering through terminal 4. Therefore flux produced by the secondary clearly opposes the primary flux fulfilling the condition set by Lenz’s law. Thus when terminal 1 is +ve terminal 3 o ...
APLYING VARIABLE SPEED DRIVES ON A GENERATOR POWER
... Historically, generators have been used on linear loads such as lights and motors running across the line. These types of loads pull current equally over the line cycle and do not distort the output voltage. These types of loads may also be more tolerant to poor voltage and frequency regulation. In ...
... Historically, generators have been used on linear loads such as lights and motors running across the line. These types of loads pull current equally over the line cycle and do not distort the output voltage. These types of loads may also be more tolerant to poor voltage and frequency regulation. In ...
Power factor
In electrical engineering, the power factor of an AC electrical power system is defined as the ratio of the real power flowing to the load to the apparent power in the circuit, and is a dimensionless number in the closed interval of -1 to 1. A power factor of less than one means that the voltage and current waveforms are not in phase, reducing the instantaneous product of the two waveforms (V x I). Real power is the capacity of the circuit for performing work in a particular time. Apparent power is the product of the current and voltage of the circuit. Due to energy stored in the load and returned to the source, or due to a non-linear load that distorts the wave shape of the current drawn from the source, the apparent power will be greater than the real power. A negative power factor occurs when the device (which is normally the load) generates power, which then flows back towards the source, which is normally considered the generator.In an electric power system, a load with a low power factor draws more current than a load with a high power factor for the same amount of useful power transferred. The higher currents increase the energy lost in the distribution system, and require larger wires and other equipment. Because of the costs of larger equipment and wasted energy, electrical utilities will usually charge a higher cost to industrial or commercial customers where there is a low power factor.Linear loads with low power factor (such as induction motors) can be corrected with a passive network of capacitors or inductors. Non-linear loads, such as rectifiers, distort the current drawn from the system. In such cases, active or passive power factor correction may be used to counteract the distortion and raise the power factor. The devices for correction of the power factor may be at a central substation, spread out over a distribution system, or built into power-consuming equipment.