Abstract: A renewable energy, utility-size electric power system is provided with a high voltage, renewable energy harvesting network connected by a direct current link to a centralized grid synchronized multiphase regulated current source inverter system. The harvesting network includes distributed renewable energy power optimizers and transmitters that control delivery of renewable energy to the grid synchronized multiphase regulated current source inverter system. A visual immersion monitoring and control system can be provided for a three dimensional, visually oriented, virtual reality display, and command and control environment.

Abstract: Solid or semi-solid feedstock is melted in an open bottom electric induction cold crucible furnace. Directionally solidified multi-crystalline solid purified material continuously exits the bottom of the furnace and may optionally pass through a thermal conditioning chamber before being gravity fed into a transport mold where an ingot of the purified multi-crystalline solid material is transported to a remote holding area after the transport mold is filled with the multi-crystalline material and cut from the continuous supply of material. Cool down of the ingot is accomplished remote from the open bottom of the electric induction cold crucible furnace.

Abstract: Apparatus and method are provided for electric induction heating and melting of a transition material that is non-electrically conductive in the solid state and electrically conductive in the non-solid state in an electric induction heating and melting process wherein solid or semi-solid charge is periodically added to a heel of molten transition material initially placed in a refractory crucible. Induction power is sequentially supplied to a plurality of coils surrounding the exterior height of the crucible at high power level and high frequency with in-phase voltage until a crucible batch of transition material is in the crucible when the induction power is reduced in power level and frequency with voltage phase shifting to the induction coils along the height of the crucible to induce a unidirectional electromagnetic stir of the crucible batch of material.

Abstract: Apparatus and method are provided for electric induction heating and melting of a transition material that is non-electrically conductive in the solid state and electrically conductive in the non-solid state in an electric induction heating and melting process wherein solid or semi-solid charge is periodically added to a heel of molten transition material initially placed in a refractory crucible. Induction power is sequentially supplied to a plurality of coils surrounding the exterior height of the crucible at high power level and high frequency with in-phase voltage until a crucible batch of transition material is in the crucible when the induction power is reduced in power level and frequency with voltage phase shifting to the induction coils along the height of the crucible to induce a unidirectional electromagnetic stir of the crucible batch of material.

Abstract: Apparatus and method are provided for electric induction heating and melting of a transition material that is non-electrically conductive in the solid state and electrically conductive in the non-solid state in an electric induction heating and melting process wherein solid or semi-solid charge is periodically added to a heel of molten transition material initially placed in a refractory crucible. Induction power is sequentially supplied to a plurality of coils surrounding the exterior height of the crucible at high power level and high frequency with in-phase voltage until a crucible batch of transition material is in the crucible when the induction power is reduced in power level and frequency with voltage phase shifting to the induction coils along the height of the crucible to induce a unidirectional electromagnetic stir of the crucible batch of material.

Abstract: Apparatus for, and method of, containing, transferring and electromagnetically stirring an electrically conductive fluid is provided. A vessel is formed from spaced-apart annular structural elements, or hoops, that are bound together by a high-temperature electrical insulating material, which also forms the interior surface of the vessel. Reinforcing members are embedded in the high-temperature electrical insulating material and passed through the hoops. The vessel is disposed within an electrical stator having multiple electrical poles. Each pole is wound with a separate coil. Current can be supplied to each coil winding, with a suitable phase shift between currents to all coil windings, to achieve an electromagnetically induced stirring and heating of the electrically conductive fluid. The vessel may be removably disposed in the electrical stator so that the vessel can be transported to and from the electrical stator for induced stirring.

Abstract: Solid or semi-solid feedstock is melted in an open bottom electric induction cold crucible furnace. Directionally solidified multi-crystalline solid purified material continuously exits the bottom of the furnace and may optionally pass through a thermal conditioning chamber before being gravity fed into a transport mold where an ingot of the purified multi-crystalline solid material is transported to a remote holding area after the transport mold is filled with the multi-crystalline material and cut from the continuous supply of material. Cool down of the ingot is accomplished remote from the open bottom of the cold crucible furnace.

Abstract: A method for setting the operating frequency of a forge welding machine for a preferred width of the of the heat affected zone during a forge weld. A computer program executes a self-tuning routine to determine the operating frequency in response to an inputted value of a preferred width of the heat affected zone. The operating power setting for the forge welding machine may also be determined in combination with the operating frequency in response to an inputted value of weld temperature.

Abstract: A renewable energy, utility-size electric power system is provided with a high voltage, renewable energy harvesting network connected by a direct current link to a centralized grid synchronized multiphase regulated current source inverter system. The harvesting network includes distributed renewable energy power optimizers and transmitters that control delivery of renewable energy to the grid synchronized multiphase regulated current source inverter system by step-up voltage boost of the DC voltage from the renewable energy sources in combination with a DC-to-DC conversion where the stepped-up voltage of the renewable sources is utilized as a positive high voltage DC output across the input of an inverter used in a DC-to-DC converter to establish an equal magnitude negative high voltage DC output across a rectified output of the inverter. A visual immersion monitoring and control system can be provided for a three-dimensional, visually-oriented, virtual reality display, and command and control environment.

Abstract: Apparatus and method are provided for electric induction heating and melting of a transition material that is non-electrically conductive in the solid state and electrically conductive in the non-solid state in an electric induction heating and melting process wherein solid or semi-solid charge is periodically added to a heel of molten transition material initially placed in a refractory crucible. Induction power is sequentially supplied to a plurality of coils surrounding the exterior height of the crucible at high power level and high frequency with in-phase voltage until a crucible batch of transition material is in the crucible when the induction power is reduced in power level and frequency with voltage phase shifting to the induction coils along the height of the crucible to induce a unidirectional electromagnetic stir of the crucible batch of material.

Abstract: An apparatus and process are provided for induction heating of a workpiece. The workpiece is moved through an inductor to inductively heat treat the workpiece with electric power of varying frequency and duty cycle or amplitude control to control the magnitude of electric power as the frequency changes. Alternatively the workpiece may be stationary and the inductor can be moved along the workpiece, or combined and coordinated movement of both the workpiece and inductor can be used.

Abstract: The present invention is apparatus for, and method of, heating, melting and purifying a material by electric induction heating in a susceptor furnace. Non-electrically conductive solid charge may initially be placed in the furnace. Output frequency from a power source supplying current to one or more induction coils surrounding the furnace is selected to maximize magnetic coupling with the susceptor material in the susceptor furnace to induce eddy current heating in the material. Heat transfers by conduction from the susceptor material to the non-electrically conductive charge placed in the susceptor furnace to melt the charge. Output frequency is reduced as the charge melts and becomes electrically conductive to enhance magnetic coupling with the melt in the furnace. Degassing of impurities from the melt can be achieved by bubbling a gas through the melt while the surface level of the melt is maintained at vacuum.

Abstract: A dual frequency output is provided from a DC to AC inverter. An H-bridge inverter is provided with switching arranged to reconfigure the inverter from half-bridge to full bridge so that the inverter's output can be switched from high frequency to low frequency, respectively. A resonant load tuning capacitance is utilized across the input of the inverter subsequent to the DC link input (for example from an AC utility fed rectifier) to the inverter. The inductive load circuit at the output of the inverter may be one or more induction coils surrounding a crucible in which an electrically conductive material is placed, or susceptor, or one or more inductors used to heat treat an electrically conductive material. In an alternative arrangement an H-bridge inverter is utilized in both the high and low frequency modes while a tank capacitance is in the circuit, or shorted out of the circuit, respectively, in the high or low frequency modes.

Abstract: An impeder for use in an electric induction welding process is provided. Optionally the impeder does not require internal forced cooling. In embodiments using internal forced cooling a high efficiency cooling system is provided.

Abstract: An impeder for use in an electric induction welding process is provided. Optionally the impeder does not require internal forced cooling. In embodiments using internal forced cooling a high efficiency cooling system is provided.

Abstract: An impeder for use in an electric induction welding process is provided. A cooling medium is circulated centrally through the impeder's magnetic material and between the interior of the impeder's high temperature enclosure and the exterior of the magnetic material within the impeder with the impeder entry and exit passages for the cooling medium located on the same side of the impeder.

Abstract: An apparatus and process are provided for directional solidification of silicon by electric induction susceptor heating in a controlled environment. A susceptor vessel is positioned between upper and lower susceptor induction heating systems and a surrounding induction coil system in the controlled environment. Alternating current selectively applied to induction coils associated with the upper and lower susceptor heating systems, and the induction coils making up the surrounding induction coil system, result in melting of the silicon charge in the vessel and subsequent directional solidification of the molten silicon. A fluid medium can be directed from below the vessel towards the bottom, and then up the exterior sides of the vessel to enhance the directional solidification process.

Abstract: The present invention relates to a method of clamping a semiconductor assembly with a desired compression force equally distributed across the opposing surfaces of the devices and associated components of the semiconductor assembly.

Abstract: Wind-generated electric power is collected in a multiple nodal arrangement where the DC output current of each node can be held constant while the DC output node voltage is allowed to vary. The DC outputs from the wind-generated power collection nodes are connected together in series and fed to a plurality of regulated current source inverters via a high voltage DC transmission link. Each inverter converts input DC power into a three phase AC output. The AC outputs of the regulated current source inverters are connected to a phase shifting transformation network that supplies three phase electric power to a conventional AC electrical transmission system. Alternatively wind-generated and photovoltaic-generated electric power is commonly collected in a nodal arrangement and transported at high voltage DC to a plurality of regulated current source inverters for supply to the conventional AC electrical transmission system.

Abstract: Power from the dc outputs of wind-generated power collection nodes is converted to ac power of suitable quality for injection into an electric power grid. Conversion is accomplished by current regulation of the dc outputs of the wind-generated power collection nodes to the input of each one of multiple inverters in a system, with each inverter outputting multiple phase currents that are out of phase with the multiple phase currents outputted from all other inverters in the system. The multiple phase currents from all of the inverters in a system are connected to the secondary windings of a phase transformation network that produces a three phase current output having a step-shaped waveform for injection into the electric power grid. Alternatively the dc input to each one of the multiple inverters may be a combination of the dc outputs of wind-generated power collection nodes and the dc outputs of solar photovoltaic power collection nodes.