736 results about "High voltage capacitors" patented technology

A flyback power converter with multiple outputs has a transformer, a low-voltage output circuit, a high-voltage output circuit, and a secondary side post regulator circuit is provided. The transformer has a first secondary winding and a second secondary winding. The low-voltage output circuit has a low-voltage output capacitor and a rectifier unit, and is coupled to the first secondary winding to generate a low voltage output. The high-voltage output circuit has a high-voltage output switch and a high-voltage output capacitor, and is coupled to the second secondary winding to generate a high voltage output. The secondary side post regulator circuit adjusts on-time of the high-voltage output switch according to a feedback signal to have the energy stored in the high-voltage capacitor transmitted to the low-voltage capacitor to lower down the voltage level of the high output voltage.

The present invention generally relates to improved capacitors; in particular, the present invention provides advanced valve metal (AVM) anodes and methods for fabricating AVM anodes having complex surface and interior features for use in high energy density capacitors. Such anodes find use in high voltage capacitors incorporated into implantable medical devices (IMDs), among other uses. The AVM anodes may be pressed into virtually any arbitrary shape and may have a gradually changing (or substantially constant) density profile throughout the AVM anode. Such AVM anodes may also be perforated or shaped to receive one or more cathode members. The AVM anodes enhance packaging efficiency for compact high energy density capacitors.

The invention relates to a high-voltage capacitor imbalance protecting method for a high-voltage DC transmission system, comprising the following steps of: (1) analyzing imbalance current of a high-voltage capacitor in breakdown of a capacitor element during failure development in a high-voltage DC transmission system; (2) judging a symmetrical or dissymmetrical failure of the high-voltage capacitor in the high-voltage DC transmission system; and (3) proposing a corresponding setting principle and an action strategy aiming at the symmetrical or dissymmetrical failure. The high-voltage capacitor imbalance protecting method for a high-voltage DC transmission system has simple structure, convenience and practicability.

A semiconductor switch 12 connected in series with a smoothing capacitor 12 is constituted by connecting in parallel a diode 13D which permits to flow current regenerated from energy of electric charges stored in a high voltage capacitor 17 to a primary side of a high voltage transformer 15 for the smoothing capacitor 12 and switching means 13S which interrupts an output from the smoothing capacitor 12, and after turning off the switching means 13S, through alternative on and off control of switching means 161S˜164S the energy of electric charges stored in the high voltage capacitor 17 is regenerated to the smoothing capacitor 12 by making use of parasitic leakage inductance 15L. As a result, an X-ray high voltage device is provided which permits to drop a wave tail of a tube voltage in a high speed without complexing the structure of the high voltage part thereof.

An electrical circuit for a photomultiplier tube (PMT) is disclosed that reduces power consumption to a point where the PMT may be powered for extended periods with a battery. More specifically, the invention concerns a PMT circuit comprising a low leakage switch and a high voltage capacitor positioned between a resistive divider and each of the PMT dynodes, and a low power control scheme for recharging the capacitors.

The invention relates to a system and a method for measuring high voltage cable space charges based on an electroacoustic pulse method. A high voltage pulse source and a high voltage capacitor are connected in series and are then connected with measuring electrodes at two ends of a tested piece, a high voltage power source is further connected with the measuring electrodes at two ends of the tested piece through a current limit resistor, a piezoelectric sensor closely clings to the lower measuring electrode, the piezoelectric sensor acquires a stress wave signal and sends the processed signal to a computer to form the measuring system, the high voltage power source can be a direct current high voltage power source and further can be an alternating current high voltage power source, the alternating current high voltage power source is connected with a phase detection unit, and a phase detection circuit outputs a synchronous control signal to a pulse generation unit of the high voltage pulse source. The high voltage power source forms space charges in an insulation layer of an electric power cable through electrodes, disturbance of the charges in the insulation layer of the electric power cable is realized through the high voltage pulse source to form dynamic stress waves, the measuring system acquires a signal of a pressure sensor, and a distribution state of the space charges of the electric power cable is analyzed. Through the system and the method, measurement on the distribution state of the space charges in the insulation layer of the electric power cable under the alternating current state is realized.

The invention provides a high-speed electromagnetic valve drive method with boosting and fault diagnosing functions. The method comprises the following steps that the inductance characteristic of an electromagnetic valve is utilized, the electromagnetic valve serves as a power inductor to charge a high-voltage capacitor, the electromagnetic valve is driven to work by controlling the on-off states of a switching tube, and the boosting function is finished in the period; if the voltage of the high-voltage capacitor does not reach the set value in the jet period, boosting can be continuously performed at the interval of two times of jet till the voltage reaches the set value; and the open-circuit fault of the electromagnetic valve and the short-circuit fault of the electromagnetic valve are judged according to the current rising speed of the electromagnetic valve. The method has the beneficial effects that no additional boosted circuit is needed, the inductance characteristic of the electromagnetic valve is utilized for charging the high-voltage energy storage capacitor, and the boosting function is finished in the jet period and at the jet interval; and the fault diagnosis of the electromagnetic valve can be finished, and when the fault happens, jetting can be stopped, and the fault is fed back to an engine control unit.

A medical device for electrical termination of an arrhythmic condition of a patient's heart in embodiments of the invention may include one or more of the following features: (a) at least one battery; (b) means for detection of an arrhythmic condition of a patient's heart; (c) at least one high voltage capacitor; (d) converter means for providing charging current from said battery to said capacitor; (e) means for maintenance of a charge on said capacitor between arrhythmia therapies; (f) controller means responsive to detection of an arrhythmic condition of said patient's heart and for providing a discharge control signal; and (g) discharge circuit means for delivering voltage stored on said capacitor to said patient's heart in response to said discharge control signal.

The invention provides a bidirectional mechanical direct-current circuit breaker based on a commutation driving circuit and a control method of the bidirectional mechanical direct-current circuit breaker. The bidirectional mechanical direct-current circuit breaker comprises a current passage branch circuit, a commutation branch circuit and an energy-absorbing and voltage-limiting branch circuit, wherein the current passage branch circuit comprises one or a plurality of mechanical switches serially connected with one another; the commutation branch circuit consists of a high-voltage capacitor and a commutation driving circuit which are connected serially; the energy-absorbing and voltage-limiting branch circuit consists of a lightning arrester; and the current passage branch circuit, the commutation branch circuit and the energy-absorbing and voltage-limiting branch circuit are connected with one another in parallel. When bidirectional current requires to be switched on or switched off, current can be transferred to the commutation branch circuit at first from the current passage branch circuit, and then is transferred to the energy-absorbing and voltage-limiting branch circuit, and finally, switch-on and switch-off of the bidirectional current are realized. The bidirectional mechanical direct-current circuit breaker based on the commutation driving circuit has the advantages of low cost, simple structure and high reliability.

The high-voltage series compensation capacitor group unbalance protection device is related to the relay protection of high-voltage transmission lines, and solves the problems of few functions and low sensitivity of the existing protection devices. Including the A/D conversion module, which converts the current generated by the capacitor bank current transformer D and the unbalanced current transformer E into digital quantities, and the data judgment and calculation module, which converts the current Ic of the capacitor bank, the unbalanced current ΔI, and the current of the capacitor bank A Threshold current Imk, capacitive reactance change rate Kx of the original H-arm capacitive reactance, reliability factor Kk to calculate the number of faulty capacitor units, storage module, storage threshold current Imk, capacitive reactance change rate Kx, reliability factor Kk, faulty The number of times and calculation results are used to protect the output module, and the judgment result of the calculation module is judged according to the data to alarm or trip protection.

The invention discloses a capacitive voltage-division type self-calibration optical voltage transducer, which is used for solving the problem that the existing capacitive voltage-division type optical voltage transducer generates measurement accuracy temperature drift under the influence of temperature and is poor in interference rejection. The capacitive voltage-division type self-calibration optical voltage transducer comprises a capacitive voltage divider, a base and an optical voltage sensor, the capacitive voltage divider comprises a high-voltage capacitor, a low-voltage capacitor, a signal output terminal and a grounding terminal; the optical voltage sensor comprises an optical voltage sensing unit, and further comprises a signal processing unit; and the signal processing unit comprises a photoelectric conversion module, an anti-aliasing filter, a band-pass filter, an amplifier, an A/D (analogue/digital) conversion module, a DSP (Digital Signal Processor),a D/A conversion module, an amplifying module, an overvoltage protection module, an LED (Light-Emitting Diode) light source, a power conversion module, a combining unit and a direct current power module, and further comprises a photoelectric hybrid connector module. The capacitive voltage-division type self-calibration optical voltage transducer is used for voltage measurement in an electric power system.

The present invention relates to control of an alternator-starter for a hybrid electric vehicle having a disconnected high-voltage battery. A hybrid powertrain system includes an electric motor/generator unit having a multiphase asynchronous AC machine electrically connected to a multiphase bridge inverter. A high-voltage capacitor is electrically connected between positive and negative sides of a high-voltage DC power bus. High-voltage DC bus pre-charge circuits are electrically connected between gate drive bias power supplies and the multiphase bridge inverter. A low-voltage battery electrically charges the high-voltage DC link capacitor via the gate drive bias power supplies and the high-voltage DC bus pre-charge circuits when the high-voltage energy storage system is disconnected from the high-voltage DC power bus.

The invention discloses a double-bus power converter for inhibiting the torque pulsation of a switched reluctance motor and a control method thereof. The double-bus power converter comprises an auxiliary power supply and a basic power converter; the auxiliary power supply comprises a power changeover switch Sa, a diode Ds1, a power side capacitor C1 and a high-voltage capacitor C2; one phase of the basic power converter comprises a switching device Sx and a diode Dx, and when the switching device conducts, winding current increases and motor output torque increases; when the switching device is switched off, the winding current is released via the diode, and the motor output torque decreases. The invention has the following advantages: only a half of controllable power devices are used, so the cost and size of the power converter are reduced; the energy of the degaussing winding of the motor is sufficiently utilized by the auxiliary power supply, so the efficiency of the motor is increased; because the voltage of the auxiliary power supply is 3 to 4 times higher than the voltage of a main power supply, the phase change time of the motor is shortened remarkably, consequently, the control method does not need advance turn-on angle and turn-off angle, and thereby the control policy is simplified.

The invention discloses a high-voltage capacitor bank branch current monitoring device, comprising a self-excitation energy obtaining and power converting circuit, a current detection and acquisition circuit, a CPU data acquisition and controlling circuit and a wireless transceiving circuit, the self-excitation energy obtaining and power converting circuit obtains energy from the high-voltage line and converts and outputs direct voltage; and the current detection and acquisition circuit collects current instantaneous value, and outputs to the CPU data acquisition and controlling device, which is used for finishing branch unbalanced current AD alternating current sampling, current harmonic calculation and finishing bidirectional wireless digital transmission via the wireless transceiving circuit. The monitoring device solves the problem of monitoring protection of a capacitor bank under high potential, discloses the damage mechanism of the capacitor bank by taking the branch unbalanced current and harmonic distribution in the fault process of the capacitor bank as the analysis basis, thus reducing fault rate of the capacitor bank and having significant meanings in improving power grid safe operation level and economic efficiency.

Accurate harmonic measurements on electrical power systems where the main instrument transformers are of the capacitor coupled voltage type (CVT type) is made possible by the provision of one or more current sensors (PQCS1, PQCS2). CVTs typically have a high voltage capacitor bank (CH) and a low voltage capacitor bank (CL). One or more current sensors (PQCS1, PQCS2) is/are positioned so as to measure capacitor current and from that the input voltage (Vin) of the CVT can be determined for each frequency.

The invention discloses a monitoring equipment power supply system for high voltage capacitor step-down electricity taking of a tower pole line. The power supply system comprises an electricity taking module, a voltage-stabilizing module, a DC/DC conversion module and a voltage comparison control module. The electricity taking module comprises a high-voltage wire, a high-voltage capacitor, a voltage transformer and an insulator. The high-voltage capacitor is connected with the insulator in parallel. A thermal explosion type disconnector is arranged between the high-voltage capacitor and the high-voltage wire. The high-voltage capacitor is connected with the voltage transformer in series and outputs 220 v voltage on the secondary side of the voltage transformer, the voltage is converted into a small current after being transmitted to the DC/DC conversion module through the voltage-stabilizing module, and then the current is transmitted to monitoring equipment. The output end of the DC/DC conversion module is connected with a fault signal return module and the voltage comparison control module. Compared with a traditional wind-solar power storage scheme, the design cost of the power part of a tower monitoring system is greatly reduced; besides, the power supply system can monitor running for a long time, is economical and practical and thoroughly solves the problem that the electricity taking of the tower is difficult.