840 results about "Voltage transducers" patented technology

The present invention provides a system for operating a power line communications system that employs surface wave communications and conducted communications. The system is comprised of a plurality of network elements, which may take the form of repeaters, communication interface devices, backhaul devices, medium voltage transducers, distribution points, aggregation points, and others. In one embodiment, surface waves are communicated over the medium voltage power lines and the conducted communications are communicated via the low voltage power lines to and from customer premises.

Apparatus and method for stimulating neuromuscular tissue in the stomach. The neuromuscular stimulator stimulates the neuromuscular tissue by applying current-controlled electrical pulses. A voltage sensor detects the voltage across the neuromuscular tissue to determine if the voltage meets a predetermined voltage threshold. A control circuit adjusts the current-controlled pulse if the voltage is found to meet the voltage threshold, such that the voltage does not exceed the voltage threshold. A voltage-controlled pulse may also be applied to the tissue. A current sensor would then detect whether the current on the neuromuscular tissue meets a predetermined current threshold, and a control circuit adjusts the voltage controlled pulse such that the current does not exceed the current threshold. A real time clock may be provided which supplies data corresponding to the time of day during the treatment period. A programmable calendar stores parameters of the stimulating pulse, wherein the parameters have a reference to the time of day.

A solar cell array control device has a plurality of solar cell modules, a bidirectional DC converter, at least a voltage sensor and a control unit. The bidirectional DC converter corresponds to and is electrically connected to the solar cell modules to connect these solar cell modules in series to form a solar cell array. The voltage sensor is electrically connected to the solar cell modules, and can generate an abnormal voltage when detecting that one of the solar cell modules is abnormal. The control unit is electrically connected to the voltage sensor and the bidirectional DC converter, and outputs a pulse width modulation signal by detecting the abnormal voltage to control the bidirectional DC converter for compensating the conversion current and thus enhancing the output power of this solar cell module.

A filter condition sensing circuit includes current and voltage sensors and a data processor. The current and voltage sensors produce signals indicating magnitudes of electrical current and voltage, respectively, provided to an electric motor used to move a fluid (a gas or liquid) through a filter element. During a first time period, the data processor uses the signals to determine an acceptable range of electrical power required by the motor. During a second time period, the data processor uses the signals to determine a magnitude of electrical power required by the motor. When the magnitude of electrical power is within the acceptable range of electrical power, the data processor generates a signal indicating a normal condition of the filter element. A described filter condition indicating system includes the circuit. A method is for determining a condition of a filter element.

Apparatus and method for stimulating neuromuscular tissue in the stomach. The neuromuscular stimulator stimulates the neuromuscular tissue by applying current-controlled electrical pulses. A voltage sensor detects the voltage across the neuromuscular tissue to determine if the voltage meets a predetermined voltage threshold. A control circuit adjusts the current-controlled pulse if the voltage is found to meet the voltage threshold, such that the voltage does not exceed the voltage threshold. A voltage-controlled pulse may also be applied to the tissue. A current sensor would then detect whether the current on the neuromuscular tissue meets a predetermined current threshold, and a control circuit adjusts the voltage-controlled pulse such that the current does not exceed the current threshold. A real time clock may be provided which supplies data corresponding to the time of day during the treatment period. A programmable calendar stores parameters of the stimulating pulse, wherein the parameters have a reference to the time of day.

A mobile host device configured to draw electrical energy from an energy storage device includes a disk drive. The disk drive includes a disk drive enclosure including a base, a spindle motor attached to the base, a disk positioned on the spindle motor, a generator and a charging circuit. The generator may be coupled to the disk drive enclosure and / or the mobile host device and generates electrical energy from the motion of the mobile host device and / or disk drive. The charging circuit is configured to charge the energy storage device using the electrical energy generated by the generator.

A voltage sensor is described that consists of a plurality of identical series-connected sections, where each section is comprised of an arrangement of impedance elements. The sensor is optimized to provide an output ratio that is substantially immune to changes in voltage, temperature variations or aging. The voltage sensor can be scaled to various voltage levels by varying the number of series-connected sections.

An ECU detects an effective value and phase of a voltage from a commercial power supply, based on a voltage from a voltage sensor. Further, ECU generates a command current, which is a command value of current caused to flow through power lines and in-phase with the voltage of the commercial power supply, based on the detected effective value and the phase and on a charge / discharge power command value for a power storage device. Then, ECU controls zero-phase voltage of inverters based on the generated command current.

A modular metering system comprises a data processing module, a current module and a voltage module. The current and voltage modules include sensor memories characterizing the respective current and voltage sensors facilitating assembly and repair of the metering system.

The invention discloses a scheme for controlling the grade parking of a permanent magnet motor-driven pure electric vehicle. The pure electric vehicle has an electrical system comprising a battery pack, a motor, a power converter, a motor controller and a vehicle controller and further comprising corresponding voltage, current and tilt sensors. The scheme comprises two steps of: (1) detection for the initial position of a rotor of a permanent magnet synchronous motor: a detection voltage is applied to the permanent magnet synchronous motor by the power converter, and the initial spatial position of the motor rotor in the case that the vehicle is stationary is calculated through a current feedback signal; and (2) torque self-balancing strategy based on vector control: the torque self-balancing characteristic can enable driving torque to track load torque automatically. The torque required by parking is calculated in accordance with the tilt angle of a ramp on which the vehicle is to be parked, and then, reasonable current amplitude and phase are given according to the initial position of the rotor and the torque required by grade parking in order to enable the driving torque to be equal to the load torque, therefore, stationary parking of the vehicle on the grade is realized.

A device for sensing electrical current or voltage in an electrical distribution system using an actively compensated current ratio transformer that includes a first magnetic core having a first permeability and a second magnetic core having a second permeability higher than the first permeability. A primary winding having P turns is coupled with the first and second magnetic cores, a measurement winding having M turns is coupled with the first and second magnetic cores so that current in the primary winding induces current in the measurement winding, and a sense winding having S turns is coupled with the second magnetic core. An amplifier coupled to the sense winding receives a voltage developed across the sense winding and produces a compensation current in response to the received voltage. The amplifier has an output coupled to the sense winding to feed the compensation current through the sense winding to reduce the voltage developed across the sense winding voltage to substantially zero. A burden resistor is coupled to the measurement winding and the sense winding for receiving the sum of the current induced in the measurement winding and the compensation current.

An inverter control apparatus and a control method thereof are provided. The inverter control apparatus and a control method thereof stably operate a three-phase motor using a capacitor having a small capacitance for a DC link. The inverter control apparatus includes a current sensor to sense an output current of the inverter, a voltage sensor to sense a DC-link voltage of the inverter, and a controller to generate an average of a periodically varying rotor based q-axis current boundary value based on the output current and the DC-link voltage to generate a current reference on the basis of the average of the rotor based q-axis current boundary value, and to drive a three-phase motor based on the current reference. Stabilized variable speed control of a motor by using a small-capacitance capacitor for a DC link of an inverter is performed and reliability of an inverter circuit improved.

There is provided an underwater measurement system (20, 30, 40) for monitoring an underwater region (10). The system (20, 30, 40) includes a sensor assembly operable to sense at least one physical variable in the region (10) for generating at least one corresponding sensor signal, and a data processing arrangement (170, 510, 520) for processing the at least one sensor signal to generate processed data for presentation and / or logging. The sensor assembly (20) includes one or more voltage sensors (190) configured to sense electric fields present in the underwater region (10) and provide information in the at least one signal indicative of the electric fields. Moreover, the sensor assembly (20) includes one or more hydrophones (200) operable to receive sonic energy generated in the underwater region (10) and to include corresponding information in the at least one sensor signal for communicating to the data processing arrangement (170, 510, 520).

A system for determining a temperature of a permanent magnet in a machine includes a voltage sensor that generates a voltage signal reflective of a stator voltage and a current sensor that generates a current signal reflective of a stator current. A processor receives the voltage and current signals and generates a temperature signal reflective of the temperature of the permanent magnet in the machine. A method for controlling a load of a machine includes generating a voltage signal, a current signal, and a temperature signal reflective of the temperature of a permanent magnet in the machine. The method further includes adjusting the load of the machine based on the temperature signal.

The invention discloses a bidirectional direct current converter based on an immittance network, and a digital control system and a digital control method of the bidirectional direct current converter. The bidirectional direct current converter based on the immittance network comprises a storage battery, a low-voltage-side filter capacitor, a first active full-bridge circuit, the immittance network, a high-frequency transformer, a second active full-bridge circuit and a high-voltage-bus-side filter capacitor. The digital control system comprises a first voltage sensor, a second voltage sensor, a current sensor and a digital signal processing (DSP) digital controller, wherein the DSP digital controller comprises a BUCK controller, a BOOST controller, a signal conditioner, a first selective switch and a second selective switch. According to the basic characteristics of the immittance network, the two active full-bridge circuits in the bidirectional direct current converter can operate with high power factor, and the current stress of a switching tube can be greatly reduced. By the adoption of the system and the method, according to the characteristics of the immittance network, the zero-current turn on and zero-current turn off of all switching devices of a high-voltage-side active full-bridge circuit are realized, and the efficiency of the converter is improved.

The invention discloses an intelligent electric meter with a function of detecting power supply reliability and a voltage qualified rate and a detecting method of the intelligent electric meter with the function of detecting the power supply reliability and the voltage qualified rate. The intelligent electric meter comprises a voltage sensor and a current sensor, and the voltage sensor and the current sensor are connected with a sampling circuit through a signal adjusting circuit; the sampling circuit is connected with a digital signal processor (DSP); and MCU is simultaneously connected with the DSP, a data memorizer, a power supply module, a local input / output (I / O) module, a remote communication module and a hardware clock. Alternative current voltage data which are collected by the intelligent electric meter not only are used for electric energy measuring and statistics, but also are used for detection and statistics of the power supply reliability and the voltage qualified rate by conducting classification, timing and accumulation on different ranges where the voltage values locate such as an over upper limit range, a qualified range, a over floor level range, a decompression range, the intelligent electric meter is enabled to possess the function of detecting the power supply reliability and the voltage qualified rate, and applied range of the intelligent electric meter is widened.

An electricity storage system includes: an electricity storage unit (10, 11) that is subjected to charging and discharging; a voltage sensor (20, 20a) that detects a voltage value of the electricity storage unit; and a controller (30) that terminates the charging of the electricity storage unit when the detected voltage value reaches a charging termination voltage value. The controller calculates a voltage drop, which is associated with interruption of constant current charging, on the basis of the detected voltage value while the constant current charging is performed in the electricity storage unit, and sets the charging termination voltage value in accordance with the amount of voltage drop.

A solid state power controller system can include a direct current load, a solid state power controller apparatus including an alternating current sensor coupled to the direct current load, a direct current sensor coupled to the direct current load, a voltage sensor coupled to the direct current load, a main switch coupled to the direct current load via the alternating and direct current sensors, an auxiliary switch coupled in parallel to the main switch, a current limiting resistor coupled in series to the auxiliary switch and a solid state power controller coupled to the main switch, the auxiliary switch, the alternating current sensor, the direct current sensor, and the voltage sensor, and a direct current power source coupled to the solid state power controller apparatus.

An inverter controller for driving a brushless DC motor, of which rotor is provided with permanent magnets, includes an inverter circuit, a position sensing circuit, a DC voltage sensor, and a conduction angle controller. The inverter circuit is connected to the brushless DC motor for driving this motor. The position sensing circuit senses a rotor position with respect to a stator from an induction voltage of the brushless DC motor. The DC voltage sensor senses a voltage value of a DC power voltage supplied to the inverter circuit. The conduction angle controller changes a conduction angle of the inverter circuit within a range less than 180 degrees in electric angles in response to a rate of change in the DC power voltage.

The invention discloses a rectification control circuit for a bidirectional CLLLC resonant converter. Both the primary side and the secondary side of the transformer in the bidirectional CLLLC resonant converter are connected to a current transformer, and the current on the power receiving side of the transformer is sampled, and It is converted into a voltage signal through a unit resistance, and connected to the inverting input terminals of two hysteresis comparators through a voltage sensor. The output signals of the two hysteresis comparators respectively drive the leading switch and the lagging switch on the power receiving side to realize MOSFET rectification. Since the on-resistance of the MOSFET is very small, the rectification control circuit for the bidirectional CLLLC resonant converter of the present invention reduces the rectification loss and improves the overall efficiency of the converter compared with diode rectification.

The invention provides a method for measuring a synchronous phasor. The method comprises the steps that a voltage transformer and a current transformer acquire a voltage signal and a current signal respectively; a secondary voltage transducer and a current transducer convert the voltage signal and the current signal into measured signals respectively; an FPGA module controls an AD sampling module to conduct AD synchronous sampling according to a clock synchronous signal and a synchronous pulse per second; an embedded processor receives AD sampling data of an FPGA. Regarding the shortcoming of a measuring method of the synchronous phasor of a conventional power system, with the combination of the characteristic of inputting the signals under the dynamic condition of the power system, the method can effectively improve the measurement precision of the synchronous phasor under the dynamic condition.

A charge control ECU stops a charge converter periodically or at a predetermined timing, and detects the open-circuit voltage of a solar cell through a voltage sensor. The charge control ECU uses a preset relational expression or map to determine the operating voltage corresponding to a maximum output power from the solar cell based on the detected open-circuit voltage. The charge control ECU causes the charge converter to resume its operation when the determined operating voltage is set at the charge converter as the target voltage.

An alternating current electrified railway traction network impedance frequency characteristic testing device is composed of a step-down transformer TP, a harmonic source HS, a monitoring device MC, a voltage transducer TV and a current transducer TA. The monitoring device MC controls that the harmonic source HS sends harmonic current and injects a primary side winding of the step-down transformer TP into a traction network. The voltage transducer TV and the current transducer TA respectively detects harmonic voltage between a contact network T and a steel rail G and the harmonic current injected into the traction network, and the monitoring device MC receives output signals of the voltage transducer TV and the current transducer TA and finishes harmonic impedance calculation. Under the situation that the contact network is electrified, an impedance frequency characteristic of the traction network can be obtained by adjusting the frequency and amplitude of the current sent by the harmonic source, and further the harmonic frequency is obtained. The alternating current electrified railway traction network impedance frequency characteristic testing device can be used for newly-constructed electrified railway joint debugging integration test and can be also used for providing technical support for solving the harmonic vibration problem and guaranteeing power supply safety of existing lines.

A closed-loop system 10 is provided for controlling a DC motor. The system includes a DC motor 12, a controller 18 associated with the motor and constructed and arranged to control operation of the motor, a voltage sensor 14 constructed and arranged to measure a voltage supplied to the motor, a speed sensor 16 associated with the motor and constructed and arranged to obtain a measured speed of the motor, and a conditioning circuit 21 constructed and arranged to receive a speed signal and condition the speed signal to provide to the controller, a nominal speed based on the voltage supplied to the motor, or nominal rate of acceleration or deceleration upon a change in the desired speed. The controller 18 is constructed and arranged to compare the measured speed with a certain speed, that is less than the nominal speed, at a voltage corresponding to a measured voltage, and if the measured speed is less than the certain speed, a fault condition is defined by the controller. The controller 18 is also constructed and arranged to compare the measured rate of change of speed with a desired rate of change of speed, that is more than the nominal rate of change of speed in the case of motor acceleration, or less than the nominal rate of change of speed in the case of deceleration, at a voltage corresponding to a measured voltage, and if the measured rate of change of speed differs significantly from the expected rate of change of speed, a fault condition is defined by the controller.

The invention relates to a small earth current grid single-phase grounding fault wire-choosing method, which comprises: 1) Collecting the zero order voltage and the zero order current signal on the voltage sensor and the current sensor of each wire and computing the zero order voltage amplitude, if the amplitude is over the limit, it quotes that it occurs the fault and collects the zero order current after four period of the fault; 2) computing the second, third and forth period effect value I1, I2 and I3 when each line zero order current fault starts and computing the gradient factor K1, K2 of each line zero order current; 3) quoting weather it satisfies K1ú¥KSET and K2ú¥KSET, wherein KSET is the gradient factor setting value with the range 1.2-2.0; 4) if it satisfies K1ú¥KSET and K2ú¥KSET, the wire is earth fault wire. The wire-choosing system comprises a microcomputer including a fault detecting open unit, a zero order current gradient computing unit and a transient gradient wire-choosing unit.

A system (10) is provided herein for monitoring the harmonic content of the RF signal delivered to an RF powered device (13). The system comprises (a) a voltage transducer (16) adapted to sample the voltage of the RF signal and to output a first signal representative thereof, (b) a current transducer (17) adapted to sample the current of the RF signal and to output a second signal representative thereof, and (c) a memory device (67) in communication with at least one, and preferably both, of the aforementioned transducers 16 and 17 and which contains calibration information specific to the transducers.

A device for sensing electrical current or voltage in an electrical distribution system using an actively compensated current ratio transformer that includes a first magnetic core having a first permeability and a second magnetic core having a second permeability higher than the first permeability. A primary winding having P turns is coupled with the first and second magnetic cores, a measurement winding having M turns is coupled with the first and second magnetic cores so that current in the primary winding induces current in the measurement winding, and a sense winding having S turns is coupled with the second magnetic core. An amplifier coupled to the sense winding receives a voltage developed across the sense winding and produces a compensation current in response to the received voltage. The amplifier has an output coupled to the sense winding to feed the compensation current through the sense winding to reduce the voltage developed across the sense winding voltage to substantially zero. A burden resistor is coupled to the measurement winding and the sense winding for receiving the sum of the current induced in the measurement winding and the compensation current.

The invention provides a ground fault line selecting method for a small current grounding system. The method comprises the steps that a zero sequence voltage transformer and a zero sequence current transformer respectively acquire zero sequence voltage signals and zero sequence current signals when the small current grounding system encounters faults, a secondary voltage transducer and a secondary current transducer convert the zero sequence voltage signals and the zero sequence current signals into measurement signals for fault line reorganization respectively, the measurement signals are processed by a programmable operational amplifier and then are transmitted to an FPGA module, the FPGA module controls an AD sampling module to carry out high-speed synchronous sampling, sampling code stream data obtained through the sampling of the FPGA module are transmitted to an embedded processor in a DMA mode, the embedded processor processes the sampling code stream data, and ground fault line selection detection is carried out. According to the ground fault line selecting method for the small current grounding system, an FPGA is utilized for controlling an AD sampling chip to achieve the high-speed sampling, DAM communication between the embedded processor and the FPGA module is achieved, data throughput capacity is improved, and the embedded processor is made to have more resources for integrated application of judgment logic of various fault line selection algorithms.