120results about How to "DC voltage stability" patented technology

The invention discloses an intelligent control module of a permanent magnet contactor, which mainly comprises a microprocessor, a rectifier and filter, an internal working power circuit, a rechargeable battery control circuit, a closing operation module, an opening operation module, an energy-storage capacitor voltage detection circuit, a control voltage detection circuit, a power off detection circuit, and a key-press setting and display control circuit; wherein, the closing operation module consists of a first MOSFET driving protection circuit and a first MOSFET; and the opening operation module consists of a second MOSFET driving protection circuit and a second MOSFET. The intelligent control module can set delay time parameters of transient interference electricity through key-presses according to requirements of a customer, realizes delay disconnection of the permanent magnet contactor and can ensure the stable and continuous operation of equipment through staying away from influences of interference electricity; and as for conditions of requiring urgent opening operation, the intelligent control module can immediately cut off the contactor through key-press control, so as to ensure the safety of the operating equipment.

The invention provides an off-grid and grid-connected operation light and storage joint power supply system which comprises a DC/AC converter for connecting a direct current bus and an alternating current bus. The alternating current bus is connected with a power grid. The alternating current bus and the direct current bus are connected with an alternating current load and a direct current load respectively. The direct current bus is connected with a photovoltaic array and a battery system through a photovoltaic DC/DC converter and an energy storage DC/DC converter respectively. According to the off-grid and grid-connected operation light and storage joint power supply system, control strategies of the off-grid and grid-connected operation light and storage joint power supply system are provided and include the off-grid state operation control strategy and the grid-connected state operation control strategy. By means of the system and a method, the defects that an existing photovoltaic power supply system is instable in power supply quality, poor in schedulability, single in operation mode, low in energy conversion efficiency and the like are overcome.

The invention discloses a charging and discharging control system and a charging and discharging control method of a flywheel battery. The system comprises a three-phase uncontrollable rectifying circuit, an energy storage filter capacitor, an insulated gate bipolar translator (IGBT) power conversion circuit, a zero passage detection circuit, a voltage detection circuit, a current detection circuit, a direct current voltage detection and overvoltage protection circuit, a sampling and filtering overcurrent protection circuit, a displacement sampling circuit, a temperature sampling circuit, a digital signal processor controller, an energy storage inductor, a three-phase linked switch and a rotary transformer signal processing circuit, wherein the energy storage inductor is connected between the output end of each phase on the alternating current side of the IGBT power conversion circuit and the input end of a flywheel motor; the three-phase linked switch is connected in parallel with the energy storage inductor respectively; and the rotary transformer signal processing circuit is connected between the signal output end of a rotary transformer of the flywheel motor and the quadrature encoder pulse (QEP) port of the DSP controller. In the method, charging and discharging control of a flywheel battery is realized based on the system. The system has stable output direct current voltage, small high-frequency ripple, quick dynamic response, and is particularly suitable for quick charging and quick discharging working conditions; and the power factor and efficiency of the system are improved greatly.

The invention provides an active power control method during a fault of a converter, and a flexible direct current power grid. The method includes: obtaining an active power reference value and an active power restriction value corresponding to a positive electrode converter or a negative electrode converter of each converter station; calculating a maximum value of the active power transferred bythe negative electrode converter or the positive electrode converter of each converter station, received by the positive electrode converter or the negative electrode converter of each converter station; and re-distributing the active power reference values of the positive electrode converter and the negative electrode converter of each converter station according to the maximum value of the active power. When any converter is withdrawn due to the fault, in order to avoid the over-voltage or under-voltage condition of the power grid and lose the active power of the power grid as less as possible, a converter active power control system re-calculates the active power reference value of each converter, the active power of the power grid is re-distributed, the direct current voltage of the flexible direct current power grid can be rapidly stabilized, the utilization rate of the active power of the flexible direct current power grid system can be improved, and the power flow of the flexible direct current power grid system can be optimized.

The invention discloses a method for keeping intermediate direct-current voltage of regeneration passing neutral section of an alternating-current transmission system stable. The alternating-current transmission system enters a phase separation region, a control system receives an entering phase separation anticipating signal and switches a traction motor into a regeneration state, regeneration torque of the traction motor is obtained according to difference of an intermediate direct-current voltage reference value and an actual value via a PI (proportion integration) controller, and parameters of the PI controller need to be adjusted according to an actual system. By the aid of the method, the alternating-current transmission system dynamically adjusts the regeneration torque of the traction motor according to needs of an auxiliary power supply system in a regeneration passing neutral section period, balance of input power and output power in an intermediate direct-current link is realized, extreme fluctuations of the intermediate direct-current voltage are avoided, and performances of the total system are improved.

The invention discloses an unbalanced power adaptive optimization allocation method for a multi-end linear system. The method employs a dual-layer control structure comprising a primary sag control layer and a power rebalance optimization layer. The power rebalance optimization layer aims at the unbalance power caused by the frequent fluctuation of a load or new energy, and an equivalent cost expression of a system additional power generation cost caused by the power rebalance is deduced based on a multi-end flexible DC polar coordinate equivalent model comprising a voltage source converter station, a radial multi-end flexible DC common DC reference voltage is introduced, and a novel active power-DC voltage sag curve is designed. The proposed method irons out the defects that the conventional optimization control strongly depends on the high-speed communication and a centralized processing layer. The method can enable the white balance power to be adaptively and economically allocatedunder the normal condition, enables the additional power generation cost of a system to be remarkably reduced, still can maintain the DC voltage stability and power balance under the fault condition,and is remarkable in control effect.

The present invention provides an improved power supply circuit for a backlight control of the LCD panel, capable of initiating a plurality of CCFL. The electrical lighting device comprises an switching electronic ballast circuit, a CCFL abnormal detective circuit, an impedance matching device at positive end of balancing current, an adjusting and enabling control device and an auxiliary power source circuit. The circuit of the electrical lighting device is designed to protect the circuit from abnormal conditions such as short-circuit occurred on a seal cover. The impedance matching device at positive end is provided in between negative ends of some cold cathode fluorescence lamps and an anode of secondary winding of the transformer to balance the CCFL current. Detective units and signals are provided to detect anode voltage in order to determine abnormality in the circuit.

A smart chair includes a seat and a power supply device installed to the seat. The power supply device is electrically coupled to a voltage detection unit and a voltage adjustment unit. The voltage detection unit is provided for detecting a load signal, and the voltage adjustment unit is provided for adjusting and outputting a DC voltage according to the load signal. The concepts of resting, leisure and business are combined to provide a chair capable of detecting and outputting an appropriate DC voltage automatically.

The invention discloses a distributed photovoltaic power generation system control strategy based on an improved virtual synchronous generator. By further adopting a DC voltage stability control technology based on the traditional virtual synchronous generator control technology to optimize the structures of a power frequency controller and an excitation controller of the virtual synchronous generator, an improved virtual synchronous generator control strategy that does not depend on the energy storage device is proposed. When the photovoltaic power output power is lower than the load power orthe grid dispatch power demand, the effect of suppressing the dropping of the DC bus voltage and maintaining the stability of the DC voltage is taken, and the purpose of power matching according to the load or grid-connected power demand is achieved such that the photovoltaic power source can directly realize grid-off or grid-connected operation in the form of a virtual synchronous generator.

A wheel rim device with patterned light capable of automatically generating electric power has a wheel rim, an automatic generating assembly, a rectifier/filter circuit, a circuit board, a programmable chip and several light emitting components. The automatic generating assembly is accommodated on an end face of a wheel axle of the wheel rim. The circuit board is disposed on a wheel spoke of the wheel rim. The rectifier/filter circuit, the programmable chip and the light emitting components are disposed on the circuit board. Input terminals of the rectifier/filter circuit are connected to lead-out wires of the automatic generating assembly. The programmable chip has a power source terminal, a trigger terminal and several I/O terminals. The power source terminal is connected with the output terminal of the rectifier/filter circuit. Each of the I/O terminals is connected with one of the light emitting components.

The invention discloses a DC regulation power supply based on a three-phase pulse rectifier and a control method thereof. The DC regulation power supply comprises a main circuit, a testing circuit and a control circuit; and the control circuit comprises a TMS320LF2407 DSP, a crystal oscillating circuit, a power supply circuit, an AD sampling circuit and a PWM output isolating circuit. The control method of the DC regulated power supply has various forms including sampling, DC voltage control, AC current control and switching logic control. The DSP is added to the DC regulated power supply and the control method thereof, so that the DC regulated power supply is able achieve the digitalized processing. The input three-phase 380V alternative voltage is processed through controllable direct-current, so that stable 600V direct current voltage is obtained. By adopting a predictive current control method, the shape of incoming current is approximate to that of a sine wave, and the incoming current is same as the input network voltage in phase position, thereby leading the AC input power factor to be approximate to 1, and greatly reducing the pollution on an electric network.

A switching power supply unit includes a primary-side rectifying circuit that is connected to a commercial power supply and is arranged to output a primary-side nonsmoothed DC voltage, a transformer having a primary winding and a secondary winding, a switching element connected in series with the primary winding to the output of the primary-side rectifying circuit and arranged to switch the primary-side nonsmoothed DC voltage, a secondary-side rectifying circuit connected to the secondary winding and arranged to output a secondary-side nonsmoothed DC voltage, and an inverter circuit connected to the output of the secondary-side rectifying circuit, and the output is supplied to a gas discharge lamp.

The invention relates to an intelligent-control multifunctional multi-type energy-storage-battery quick charging system. The system is composed of a main circuit and subcircuits. The main circuit comprises a single chip microcomputer, a voltage input circuit, a power source circuit, an oscillating circuit, a keyboard input and display alarm circuit, a signal collection processing circuit and a signal output circuit, wherein the power source circuit is further connected with the subcircuits. Compared with the prior art, the system has the advantages that the functions of leakage detection, heat management, battery equalization management, alarm reminding, surplus capacity calculation, discharger power, SOC, SOH and DOD state reporting are achieved for batteries; the system has the functions of overvoltage protection, battery heat management and the like; corresponding charging methods are designed for different types of energy storage batteries, so that all types of the energy storage batteries can be charged under the optimal charging methods; the function of controlling the maximum output power and other functions can further be achieved for electric cars and the system further has the advantages of being simple in device, small in size, light in weight, quick in reaction speed, low in cost, long in service life and the like.

The invention discloses a small-impact-current low-voltage current converter soft-starting control method. The method is suitable for a small-impact-current low-voltage current converter soft-starting circuit, which is formed by a DC side soft-starting resistor; a switch device IGBT connected in series with the soft-starting resistor; and a single-pole DC circuit breaker connected in parallel with a series branch formed by the soft-starting resistor and the IGBT to serve as a by-pass switch. The circuit is connected between a DC bus and a DC capacitor to form a small-impact-current soft-starting loop of the device. Through the method above, the three-phase current converter can finish the soft-starting process quickly, and meanwhile, impact of the current converter to an AC system and the device of the current converter itself in the soft-starting process can be further reduced; and operation safety of the device is protected, and meanwhile, influence of the device on the system in the soft-starting is reduced.

The invention discloses an electric energy extracting device for cable partial discharge on-line detection. The device comprises a clamp-on transducer, a controlled rectifier and a rechargeable battery pack. When the device is used for field inspection, the clamp-on transducer of the device is connected at any position along a to-be-detected cable in a sleeving manner and can be used for inducing three-phase alternating current. The induced three-phase alternating current is sent to the controlled rectifier for rectifying, and the rectified DC can be used to charge the rechargeable battery pack, so as to provide a high-quality power supply to a load. The controlled rectifier comprises a control center, the control center samples the rectified DC voltage and compares the rectified DC voltage with the voltage of the rechargeable battery pack in real time, and through the adjustment of the conduction angle of the controlled rectifier, and the rectified DC voltage can be adjusted so as to ensure constant rectified DC voltage. According to technical scheme disclosed by the invention, the device can take electric energy any position on the cable between a switch cabinet and a terminal device and can provide the high-quality power supply for the load.

The invention discloses a gallium-arsenide-based thermoelectric-photoelectric micro sensor in a self-powered radio frequency transceiver module. The gallium-arsenide-based thermoelectric-photoelectric micro sensor is of an array structure composed of a plurality of identical sensor modules. Each sensor module is provided with a plurality of sets of thermoelectric couplers connected in series. The hot end of the sensor is placed on a heat concentrated portion (radiating plate) of a power amplifier, and the cold end of the sensor is far away from the heat concentrated portion and is close to an outer metal shell (heat sink plate), so that the larger temperature difference is formed between the hot end and the cold end. Direct-current voltage output is generated on the sensor array on the basis of the Seebeck effect, and the direct-current voltage conducts battery charging and energy storage on a battery to be charged. A PN junction is manufactured on the top of a semiconductor thermocouple arm of the sensor, a current path forward direction ordered arrangement is formed, the heat sink plate above the PN junction is provided with holes so as to increase the illumination area, and the photoelectric micro sensor capable of collecting light energy is formed. Compared with a traditional self-powered sensor collecting single energy, the gallium-arsenide-based thermoelectric-photoelectric micro sensor in the self-powered radio frequency transceiver module can collect light energy and heat energy at the same time to achieve the self-powered function, is smaller in size, and greatly improves power supply capability. In addition, the heat radiated when the radio frequency transceiver module works is effectively absorbed, and the radiating performance of the radio frequency transceiver module is improved.

The invention provides a photovoltaic intelligent power generation system. The photovoltaic intelligent power generation system comprises a photovoltaic battery, an MPPT solar controller, a one-way DC/DC conversion unit, a two-way DC/DC conversion unit, a storage battery pack and an inversion unit. The output end of the photovoltaic cell is electrically connected with the input end of the MPPT solar controller and the input end of the one-way DC/DC conversion unit. The output end of the one-way DC/DC conversion unit and the first end of the two-way DC/DC conversion unit are electrically connected with a direct current bus, and the second end of the two-way DC/DC conversion unit is electrically connected with the storage battery pack; the MPPT solar controller is also electrically connectedwith the storage battery pack; the MPPT solar controller tracks the maximum output power of the photovoltaic cell, and selectively introduces the output voltage of the photovoltaic cell correspondingto the maximum output power into the input end of the one-way DC/DC conversion unit; and the MPPT solar controller also adjusts the output power of the storage battery pack.

The invention discloses a multi-input rectifying circuit for distributed power generation, which is formed by connecting n rectifying units, wherein n is not less than 2; each rectifying unit comprises a bridge type rectifier, a second diode and a semiconductor switch; an alternating current input end of each bridge type rectifier is connected with a group of independent alternating current power supply; a positive output end at a direct current side is connected with one end of each semiconductor switch; a negative output end at the direct current side is connected with a positive electrode of the second diode; a negative electrode of the second diode is connected with the other end of the semiconductor switch and used as a positive output end of the rectifying unit; the second diodes of the n rectifying units are connected in series in sequence by the same polarity; positive output ends at the direct current sides of the bridge type rectifiers of adjacent rectifying units are respectively connected together through first diodes; and the polarities of the first diodes are consistent with the second diodes in the rectifying units. The rectifying unit has simple structure, can output relatively-stable direct current voltage under the condition that the input voltage substantially changes by dynamically changing an electric connecting structure of the rectifying units in the running and is applicable for a small-scale wind driven generator group.

The invention provides a coupling reactor high-voltage direct current fault current limiter. The coupling reactor high-voltage direct current fault current limiter comprises: a coupling reactor unit,a current limiting unit, an energy absorbing unit and a DC circuit breaker unit. The coupling reactor unit is composed of a coupled reactor and a line. When a short trouble is generated, the primary inductor of the coupling reactor and the precharge capacitor of the current limiting unit oscillate, a negative voltage is generated at the secondary side to reduce the current required to be cut off and the line inductor initial energy, and the secondary inductor is the line flat-wave inductor; when the fault occurs, the current limiting unit cooperates with the coupling reactor to generate a negative voltage on the line side; the energy absorbing unit is a diode in serial connection with the resistor to suppress the primary side inductor energy to be transmitted to the secondary side of the coupling reactor; the DC circuit breaker unit includes a DC breaker and a lightning arrester, the breaker cut off the fault current, and the arrester absorbs the energy stored by the inductor. The coupling reactor high-voltage direct current fault current limiter provided by the invention achieves the control of the fault current and the energy absorption limit of the lightning arrester, the capacitor parallel connection reduces the capacity and the cost is low.

The present invention provides a DC power grid voltage control method. According to whether the converter station has an ability to regulate voltage or not, the converter station is divided into three categories, namely a voltage control converter station, an auxiliary voltage control converter station, and a power control converter station. The voltage control converter station works in a constant voltage control mode or a current limit control mode; the auxiliary voltage control converter station works in an auxiliary voltage control mode, a constant DC voltage control mode or a power control mode; the power control converter station works in a constant power control mode. Through the adoption of the voltage control method disclosed by the invention, the DC voltage and the power can be controlled accurately in a steady state, and the voltage and the power can be stabilized in a transient state.

The invention discloses a temperature control system for tap heating. The temperature control system for tap heating comprises a 220V alternating-current power supply, an AC/DC conversion unit, a signal acquiring and processing unit, a reference source signal comparison circuit, a control unit and a heater, wherein the AC/DC conversion unit adopts a nonlinear switch power supply mode, and provides direct-current voltage for the reference source signal comparison circuit, the signal acquiring and processing unit and the control unit, the signal acquiring and processing unit acquires a temperature and processes the acquired signal, and the heater is controlled to carry out intelligent heating after the signal obtained by the signal acquiring and processing unit is transmitted to the control unit by the reference source signal comparison circuit. The system adopts the nonlinear power supply mode to improve the stable direct-current voltage and controls the work of the heater through comparing the acquired temperature with reference source voltage, thereby being simple in control structure, safe to use and high in work efficiency and truly reaching an intelligent level.