2055 results about "Transformer windings" patented technology

A modulated transformer-coupled gate control signaling method and apparatus provides reduction of circuit complexity and robust design characteristics in switching power circuits having a transformer-coupled gate drive. A modulated control signal at a rate substantially higher than the switching circuit gate control rate is provided from the controller circuit to a demodulator via transformer coupling. Power for the demodulator can be obtained by rectifying the modulated control signal at the demodulator, or from another transformer winding. The modulation scheme is chosen to have a DC average value of zero, eliminating any magnetization current management requirements. The modulated control signal may carry redundant control information and/or may encode additional information to provide a more sophisticated gate drive control, such as oversampled gate control information.

The present invention provides a transformer formed from adjacent conducting layers of a multi-layer PCB and at least one additional conducting layer in contact with the PCB. The inventive transformer includes one or more winding turns of a first winding formed by connecting the multiple layers of the multi-layer PCB with conductive vias and one or more winding turns of a second winding formed by connecting one or more other layers of the multi-layer PCB. The additional conducting layer or layers is connected to respective selected one or more of said conducting layers of said PCB. In one embodiment, an additional conducting layer is soldered to a top conducting layer of the PCB, effectively increasing the cross-sectional area of the top winding layer. In another embodiment, an additional conducting layer is separated from a conducting PCB layer formed on the surface thereof by a layer of insulation, permitting the additional conducting layer to form a separate winding turn. The inventive transformer can be surface mounted to a PCB, and can be used in other electromagnetic devices. The windings thus constructed are capable of accepting larger currents with lower resulting temperature increases than windings formed only from PCBs, and are less expensive to manufacture than PCB-only windings.

A system and method are provided to isolate outputs of parallel converter threads of a power system converter of a wind turbine generator by utilizing isolated power windings on the output transformer from the converter. Such isolation eliminates the circulating common mode current between the parallel converters of the wind turbine system and eliminates the need for a common mode inductor. System reliability is enhanced and total system cost is reduced.

A transformer interface prevents a false ground fault interrupt in a power supply arrangement. The power supply arrangement has a line wire and a neutral wire connected by way of a ground fault interrupt circuit to an electrically powered device, to which a ground wire is also coupled. The interface has current imbalance sensor transformer windings coupled to the line and neutral wires. A ground wire current sensor transformer winding is coupled to the ground wire. A detector transformer winding produces a signal that triggers operation of the ground fault interrupt circuit, in response to the difference between currents produced by the current imbalance sensor transformer windings exceeding detected ground wire current by a prescribed value.

The invention discloses an on-line monitoring device of transformer winding state and a monitoring method thereof. The device is used for the on-line monitoring of transformer winding deformation and bad winding contact and comprises an information acquisition unit, a parameter identification unit, a parameter processing unit and a diagnosis monitoring strategy adjusting unit, wherein the information acquisition unit collects voltage and current information on the original side and the secondary side of the transformer in real time by a data channel; the parameter identification unit identifies the winding resistance and leakage inductance parameter of the winding state of a representation transformer by the real-time voltage and current information provided by the signal acquisition unit; the parameter identification unit calculates the deviation value of a parameter value obtained by analysis and identification and a parameter reference value and takes the deviation value as the characteristic quantity which is used for measuring the quality degree of the transformer winding state; the parameter processing unit and the identification unit ensure the real-time monitoring of the transformer winding state; the diagnosis monitoring strategy adjusting unit judges whether the winding has the defect of deformation or bad contact according to the deviation value of the parameter, and takes corresponding monitoring strategy adjusting scheme according to defect types and severity thereof; and the transformer directly stops operating when the defect is serious.

A power converter nearly losslessly delivers energy and recovers energy from capacitors associated with controlled rectifiers in a secondary winding circuit, each controlled rectifier having a parallel uncontrolled rectifier. First and second primary switches in series with first and second primary windings, respectively, are turned on for a fixed duty cycle, each for approximately one half of the switching cycle. Switched transition times are short relative to the on-state and off-state times of the controlled rectifiers. The control inputs to the controlled rectifiers are cross-coupled from opposite secondary transformer windings.

A packaging system for a high current, low voltage power supply. The power supply uses bare die power FETs which are directly mounted to a thermally conductive substrate by a solder attachment made to the drain electrode metallization on the back side of the FETs. The source electrode and gate electrode of each FET are coupled to the circuitry on an overhanging printed circuit board, using CSP solder balls affixed to the front side of the FET die. The heat generated by the FETs is effectively dissipated by the close coupling of the FETs to the thermally conductive underlying substrate. High interconnect densities are achieved through the use of a multilayer printed circuit board. This high interconnect density, with the addition of a magnetic core element, allows the power supply packaging system to incorporate transformer windings for an isolation transformer or an inductor.

The invention relates to impulse response analytical test apparatus and method for detecting deformation of transformer winding, belonging to the technical field of transformer winding detection. The apparatus mainly comprises an impulse generator, a broadband digital oscilloscope, a computer, a high-voltage probe, a head end signal impedance matching device, a tail end signal impedance matching device and a screened coaxial cable. In the method, site test and analysis are carried out by using the apparatus. The invention has the advantages of high test sensitivity, rapid detection, strong capacity of resisting disturbance and flexible analytical method, and can detect slight deformation of the transformer winding and judge early potential faults effectively with high judging accuracy. The invention can be widely applied to the detection of the deformation of the transformer winding and the state overhauling.

A transformer assembly includes a transformer having a winding, a thermal sensor in thermal communication with the transformer winding, and an airflow generator in signal communication with the thermal sensor and arranged for fluid communication with the transformer winding. The airflow generator is responsive to the thermal sensor to direct an airflow toward the transformer winding in response to a temperature at the winding.

A drive transformer and associated circuitry for providing power and appropriate delays to primary switches and synchronous rectifiers in switch-mode power converters. The circuitry takes advantage of the leakage inductances of the drive transformer windings as well as the input capacitance of the primary switches (MOSFETs) to provide the necessary delays. No separate circuitry is needed to provide such delays, thereby providing reliability. Exemplary embodiments further disclose means to disable or enable the primary winding from a condition sensed on the secondary side even with a control and feedback circuit located on the secondary side.

The invention discloses a tester and a testing method for the winding lead material of a transformer, belonging to the field of electric measuring instruments, in particular to the field of power supply apparatus detection. The tester comprises a direct current power source, a voltage sampling sensor and a current sampling sensor which are all arranged in a shell; a connecting terminal arranged outside the shell, a processor, a storage and a display; the input end of the processor is respectively connected with the voltage sampling sensor and the current sampling sensor, the data terminal of the processor is connected with the storage, the output end of the processor is connected with the display, the output end of the direct current power source is connected with the connecting terminal at the outer side of the shell by a lead, the voltage sampling sensor is arranged at two sides of the output end of the direct current power source, the current sampling sensor is arranged on the lead between the direct current power source and the connecting terminal. By adopting the invention, different material coils can be conveniently detected and distinguished, thereby preventing users from cheating.

The invention discloses a method for detecting micro deformation of a transformer winding, which comprises the following steps: a pulse signal with a frequency higher than 1KHz is input into a transformer and the signals of an input terminal and an output terminal of the transformer are acquired by a sensor, after the signals acquired are processed, the transmission functions of the output terminal and the input terminal are computed, a correlation coefficient is computed by utilizing the transmission functions computed and a transmission function prior to the initial use of the transformer, if the correlation coefficient is judged to be smaller than the threshold value, an alarm signal of winding deformation is sent; and if the correlation coefficient is judged to be bigger than or equal to the threshold value, the acquired signals are processed and then saved into a database. The method for detecting micro deformation of transformer winding has simple measuring procedure, is easy to realize, can adjust measure precision on transformer deformation by adjusting the threshold value of the correlation coefficient and overcome the technology difficulty of deformation detection of the transformer for long time, and is easy to popularize.

The invention relates to system and method for detecting the transformer winding state by using constant-current sweep frequency power source excitation. A measurement and control analysis module controls sweep frequency power source and applies output constant-current sweep frequency excitation signals by an exciting transformer at a high-voltage side of the transformer to be detected; a vibration sensor measures vibration response signals of a transformer winding to be detected at different excitation frequencies; a vibration signal collector collects and preprocesses the signals measured by the vibration sensor; and the measurement and control analysis nodule carries out spectrum analysis to the received and processed vibration response signal data, displays and records a resonant frequency curve of the transformer winding on a frequency domain, compares with the resonant frequency curve previously measured and recorded as well as the vibration frequency curve of a transformer three-phase coil, and judges the state of the transformer winding to obtain the measuring result. The invention can effectively and sensitively detect the states of looseness or deformation of the transformer winding for prompt repair or replacement so as to avoid a fault of abrupt short circuit of the transformer caused by damage of the winding structure.

The invention relates to a method of utilizing the vibration waveform for detecting the state of the transformer winding. A transformer winding is viewed as a mechanical system; and if the winding is loosened or deformed, the mechanical characteristics of the winding changes, thus the corresponding mechanical characteristics of the transformer winding under the action of the impulse current are detected and the loosening and deforming condition of the transformer winding can be detected sensitively.

The present invention is a method of and an apparatus for measuring resistances of at least one transformer winding (109) in configurations of connected transformers windings. The method is based on increasing driving power from the source of electrical energy (12, 102) until the current reaches a predetermined level, which is below the core saturation current level of the measured transformer or the measuring device current limit, and then controls the power of the source of the electrical energy to maintain predetermined current flowing through the at least one winding over a time period sufficient to cause a L di/dt contribution to a voltage drop across the at least one winding to decrease below a threshold level. The apparatus measures simultaneously the constant current flowing in the at least one winding and the voltage drop over the at least one winding after the predetermined time period has elapsed. The resistance of the at least one winding is calculated from the voltage drop over the at least one winding and the current flowing in the at least one winding.

The invention relates to the field of switching converters, and particularly relates to a flyback active clamp-type switching converter control circuit and a control method thereof. The active clamp flyback circuit of the invention can realize reduced frequency and ZVS, and comprises a main power circuit, a clamp circuit, and an output rectification filter circuit, wherein a transformer and a main switching tube are connected to form the main power circuit; a clamp switching tube and a clamp capacitor and a clamp diode are connected to form the clamp circuit; and an output rectification diode and an output capacitor are connected to form the output rectification filter circuit. In comparison with the prior art, reduced frequency in light load can be realized, and the control scheme is flexible; switching loss in no load and loss of a transformer winding and switching tube inner resistance caused by a current effective value are little, no-load power consumption is greatly reduced, and the light-load efficiency is improved.

An apparatus and method for reducing common mode noise capacitive coupling from a primary winding to a secondary winding in a transformer. In an embodiment, the primary winding has two terminals and a plurality of coil turns therebetween formed by a plurality of PCB layers sandwiched together, each having at least one of the coil turns formed thereon. The coils turns on each PCB layer are connected in a predetermined way to form the primary winding. Each terminal of the primary winding is connected to a coil turn on a separate corresponding PCB layer. The PCB layers are stacked layers to form the primary winding. The secondary winding or windings are positioned adjacent to a selected one of the stacked PCB layers that is in a position in the stack substantially midway between the first and second PCB layers. Preferably, the PCB layer closest to the secondary winding is comprised of only one coil turn so as to further minimize the common mode noise. In an alternative embodiment, the transformer windings are positioned in a secondary-primary-secondary arrangement wherein two halves of the primary winding are combined into one PCB winding. Alternatively, the present invention may be used for a planar matrix transformer.

An embodiment apparatus comprises a secondary synchronous rectifier and a secondary gate drive controller coupled to a transformer winding. The secondary gate drive controller is configured to generate a forward gate drive signal for the forward switch and generate a freewheeling gate drive signal for the freewheeling switch, wherein the secondary gate drive controller generates a dead time between the forward gate drive signal and the freewheeling gate drive signal.

In a three phase transformer core, amorphous metal strips are wound into rings that are combined into frames and assembled to define cores with leg cross sections that have more than 4 sides to facilitate winding transformer windings onto the legs using winding tubes. The amorphous metal layers are secured relative to one another and the core made more rigid using resin, silicon steel layers included in the amorphous metal core, or by using strapping or tying devices.

An electric network transformer monitoring device comprises a data acquisition unit, a communication unit, a data processing unit, a control unit and a power supply unit, wherein the data acquisition unit consists of a filter circuit, a sampling circuit and a GPS timing circuit. The monitoring method provided by the invention applies unified time labels on the acquired transformer parameters through the GPS timing circuit of each electric network transformer monitoring device, transmits the monitored transformer parameters to an electric network dispatching center, judges and positions the internal faults of each transformer winding in the electric network, carries out the voltage stability analysis of the whole electric network according to the state of each transformer at the same time, reliably guarantees the safe and stable operation of local electric networks, and realizes the real-time monitoring of the wide-area electric network.