Inductor

About: Inductor is a research topic. Over the lifetime, 52565 publications have been published within this topic receiving 484068 citations. The topic is also known as: passive two terminal.

Novel technique for maintaining balanced internal DC link voltages in diode clamped five-level inverters

Abstract: The paper considers the problem of providing four regulated DC sources for use in a diode clamped five-level inverter. The preferred approach is to provide a single DC link supply and subdivide this into five levels using four series connected capacitor banks which have equally balanced voltages. The paper first considers the use of modified output switching strategies to redistribute energy through the DC link capacitors and maintain correct voltage balance, but concludes that this technique is restricted to outputs with a low modulation. The paper then presents a new technique whereby the voltage across each of these capacitors is maintained constant using a switching circuit: the balancer circuit. The design and control of the balancer circuit is described and its operation is validated on an 11 kW prototype vector controlled induction motor drive. Full four-quadrant operation is demonstrated. This arrangement eliminates the need for complex isolated supply arrangements typically found in multilevel drives. The balancer circuit takes the form of a fourth output leg with the addition of two inductors. This circuit is certainly viable for medium voltage drive applications.

High efficiency electronic ballast for high intensity discharge lamps

Abstract: An electronic ballast is powered by power source (102) and (104). The ballast controls the electrical power supplied to a gas discharge lamp (116), providing the voltages and currents required to start, warm-up and operate the lamp (116). Line power conditioner (100) reduces interference and harmonic generation, and provides a source of DC power (103), which may be regulated. DC power (103) is applied to inverter (105), which generates a square-wave voltage at a variable frequency determined by control circuit (200). Inverter (105) output is connected to resonant circuit (600) consisting of series inductor (110), series capacitors (112) and (118), and parallel inductor (114), across which gas discharge lamp (116) is connected. Operation begins with inverter (105) running at a frequency initially near but above the unloaded series resonance frequency of resonant circuit (600). Controller (200) reduces the frequency until resonant circuit (600) gives sufficient voltage to start lamp (116). After lamp (116) starts, controller (200) increases inverter (105) frequency to an intermediate frequency near but above one-third of the resonance of the series inductor (110) and the capacitors ( 112) and (118 causing a high current to flow in lamp (116), for warm-up. After a warm-up interval, controller (200) further increases inverter (105) frequency to a final value which is also above the frequency of acoustic arc resonance and above the loaded resonance frequency of resonant circuit (600).

Tunable matching circuit

Abstract: The present invention provides for low loss tunable matching circuits at rf frequencies. Ferro-electric materials are used to produce low loss tunable capacitors and inductors for use in matching circuits.

Composite magnetic core for switch-mode power converters

Abstract: A composite magnetic core formed of a high permeability material and a lower permeability, high saturation flux density material prevents core saturation without an air gap and reduces eddy current losses and loss of inductance. The composite core is configured such that the low permeability, high saturation material is located where the flux accumulates from the high permeability sections. The presence of magnetic material having a relatively high permeability keeps the flux confined within the core thereby preventing fringing flux from spilling out into the winding arrangement. This composite core configuration balances the requirements of preventing core saturation and minimizing eddy current losses without increasing either the height or width of the core or the number of windings.

Electrostatically tunable magnetoelectric inductors with large inductance tunability

Abstract: An electrostatically tunable magnetoelectric inductor including: a substrate; a piezoelectric layer; and a magnetoelectric structure comprising a first electrically conductive layer, a magnetic film layer, a second electrically conductive layer, and recesses formed so as to create at least one electrically conductive coil around the magnetic film layer; with a portion of the substrate removed so as to enhance deformation of the piezoelectric layer. Also disclosed is a method of making the same. This inductor displays a tunable inductance range of >5:1 while consuming less than 0.5 mJ of power in the process of tuning, does not require continual current to maintain tuning, and does not require complex mechanical components such as actuators or switches.