79results about How to "Avoid Voltage Fluctuations" patented technology

Each pixel is provided with a photoelectric converting device S1(1-1) or the like, a source-follower-type first transistor T1(1-1) or the like, a second transistor Te(1-1) to be turned on when reading an electrical signal from a pixel selected by a shift register SR1 for each line and outputting the signal to a readout circuit unit and a third transistor T3(1-1) to be turned on when resetting a photoelectric converting device set to a pixel selected by a shift register SR1 for each line. Moreover, a bias power source for supplying a photoelectric conversion bias to a photoelectric converting device and a reset power source for supplying a reset bias to a photoelectric converting device are set in the readout circuit unit. By using the radiation image pickup apparatus and its control method, it is possible to improve the S/N ratio while restraining noises and preferably, it is possible to perform stable and high-speed dynamic-image photographing and restrain dark current.

A dual-mode comparator may include an object voltage input unit that generates a first current flowing through a first path and a second current flowing through a second path based on a first object voltage and a second object voltage, a current mirror unit that performs a current-mirror operation for the first path and the second path to output a comparison voltage at an output terminal, a bias unit that generates a bias current corresponding to a sum of the first current and the second current, and a mode switching unit that controls the current mirror unit to have a first structure in an auto-zero mode and that controls the current mirror unit to have a second structure in a comparison mode.

The invention discloses an APF (Active Power Filter) parallel system. The APF parallel system comprises a plurality of APFs connected with a power grid, and a detection control unit. High-voltage ends of direct current support capacitors of all the APFs are commonly connected, and low-voltage ends of the direct current support capacitors of all the APFs are commonly connected. The parallel system provided by the invention only needs a set of detection control equipment to control the plurality of APFs, thus, less hardware resource is occupied. Simultaneously, the invention further discloses a control method of the APF parallel system. The control method comprises the following steps of: (1) obtaining state information of the power grid, the loads and the parallel system; (2) extracting a current instruction from the load current; (3) calculating a current error signal; (4) performing repetitive control and PI (proportional integral) regulation on the current error signal to obtain a modulation signal; (5) forming a PWM (Pulse-Width Modulation) signal. The method provided by the invention has higher reactive compensation precision and harmonic suppression capability, and can effectively suppress system circulating current.

The invention provides a constant-voltage sorting charging method of a hybrid MMC and a starting method and device. The constant-voltage sorting charging method comprises the steps of sorting full-bridge sub-modules and half-bridge sub-modules; cutting off a plurality of sub-modules with relatively high voltage for active constant-voltage charging until the voltage of the sub-modules is close to a rated value; unlocking a converter; and when the full-bridge sub-modules receive a lock instruction for charging, conducting any full-controlled device and turning off other three full-controlled devices. The charging starting process of the hybrid MMC employing the sub-modules can be completed without judging the current direction, so that the problem of voltage fluctuation of sub-modules at the end of the charging stage due to the fact that a half-bridge topology and a full-bridge topology are not consistent is effectively solved.

The invention relates to a control method for a bidirectional quasi-Z-source inversion type motor driving system. The control method comprises the following steps of collecting the voltage of a capacitor C2 and the current of a permanent magnet synchronous motor; obtaining voltage components of a d axis and a q axis; obtaining a direct-connection duty ratio; carrying out an SVPWM (space vector pulse width modulation) algorithm by inserting the direct-connection duty ratio according to the voltage components of the d axis and the q axis and the direct-through duty ratio to obtain six paths of PWM control signals for controlling the on and off of three-phase bridge arms of a three-phase bridge type inverter; and carrying out logic calculation on the six paths of PWM control signals to output a PWM control signal for controlling the on and off of an IGBT switch tube S7. Compared with the prior art, the average direct-connection duty ratio and the capacitor voltage closed loop control closed loop policy are added to the conventional SVPWM control method, so that the direct current side voltage has the voltage boosting capability; and on the basis, the power switch S7 which is complementary with the direct-connection state is further designed, so that the bidirectional flow of energy can be realized.

The invention discloses a two-way four-quadrant frequency converter, and belongs to the technical field of low power wind power generation. The two-way four-quadrant frequency converter comprises a switching power supply, a driving protective circuit, a program upgrading interface circuit, a coder interface circuit, a DSP (digital signal processor) controller, a first drive circuit, a second drive circuit, a signal acquisition circuit, an alternating-current input reactor, a first circuit breaker, a grid-side frequency converter, a rapid overflowing fuse protector, a current foldback circuit, a motor-side frequency converter and an alternating-current output reactor. According to the invention, the two-way four-quadrant frequency converter avoids the situation that two controllers can not simultaneously achieve coordination control so as to cause direct current bus voltage fluctuation under the occasion of load power and power-supply voltage jump and the like, and the direct current bus voltage after control is more stable; and the two-way four-quadrant frequency converter solves the defects that the electricity is taken from a direct current bus, the integration level of the frequency converter is improved, the structure of the frequency converter is simplified, and the safe operation of the frequency converter is farthest ensured.

A current-mode logic (CML) circuit includes: a first field effect transistor (FET) operable based on a digital signal; a second FET operable based on an inverted digital signal; a first load circuit connected to the drain of the first FET; a second load circuit connected to the drain of the second FET; a first current limiter circuit connected between a ground line and a source node, at which the sources of the first and second FETs are connected in common; and a second current limiter circuit connected between a power supply line and a drain node, at which power line sides of the first and second load circuits are connected in common, so that the CML circuit can operate stably even with low voltage power supply.

A power conditioner for a feeding system which stabilizes a load of active power is provided. A power conditioner for a feeding system comprises a first AC-DC and DC-AC converter for performing conversion between AC power and DC power; and a nickel-metal hydride battery disposed between and connected to a high-voltage cable at DC side of the first AC-DC and DC-AC converter and a low-voltage cable at the DC side of the first AC-DC and DC-AC converter.

The present invention provides a semiconductor device capable of realizing power saving and improvement in reliability or reduction in area. A semiconductor device includes: a power switch connecting an internal power supply in which power is not shut down and an internal power supply in which power is shut down; and an internal voltage determining circuit for determining voltage of the internal power supply in which power is shut down. Voltage of the internal power supply in which power is shut down is generated from voltage of an external power supply by using a regulator circuit. When the power of the internal power supply is interrupted, the power switch is turned off, the regulator circuit is turned off, and an output of the regulator circuit is shorted to a ground potential. When the power of the internal power supply is resumed, the regulator circuit is turned on, shorting is cancelled, the increased voltage of the internal power supply is determined by the internal voltage determining circuit, operation of a circuit block is started, and the switch is turned on.

A plasma display device such that fluctuation of discharge start voltage and lowering of luminance would not easily occur, the burning phenomenon of the screen is suppressed, and excellent reliability and long life can be secured, and a method of producing the same, are disclosed. The plasma display device comprises a first panel (10) provided with discharge sustaining electrodes (12) and a dielectric layer (14) on the inside thereof, and a second panel (20) laminated on the first panel (10) so that discharge spaces (4) are formed on the inside of the first panel (10), and the trap density and/or the movable metallic ion density in the dielectric layer (14) is not more than 1x10<18 >pieces/cm<3>, preferably not more than 1x10<17 >pieces/cm<3>.

An auxiliary power supply unit which is mountable to a portable electronic device having a battery, includes at least one capacitor, and an I/F connector which is connectable to an I/F connector of the portable electronic device, the I/F connector of the portable electronic device including power terminals connected to the battery. The I/F connector of the auxiliary power supply unit includes power terminals connected to the at least one capacitor, wherein the at least one capacitor is connected in parallel to the battery when the auxiliary power supply unit is mounted to the portable electronic device via the power terminals of the I/F connectors.

A rotary speed - analog voltage conversion module comprising an outer casing and an electronic circuit, the circuit includes at least rotary speed signal detection circuit, signal processing circuit,signal calculation single chip computer, D/A conversion circuit, error detection circuit, display circuit, memory device and a power supply, the rotary speed signal detection circuit includes an approach switch, the signal processing circuit comprises an photoelectric coupler and a trigger unit, the drive circuit contains an arithmetic magnifier, the error detecting circuit comprises MAX813L reset and watchdog circuit. The advantages of the invention are simplified structure, low cost in making and operation, thus the invention may be widely applied in the automatic packaging units.

The invention relates to a photovoltaic reverse-power closed loop control system and method. A photovoltaic reverse-power monitoring device detects the reverse-power of a grid-connected point, obtains the control power according to the set reverse-power constant value and generates a control signal; the control signal is transmitted to an inverter by a site bus; each inverter feedbacks respective output power to the photovoltaic reverse-power monitoring device in real time; the photovoltaic reverse-power monitoring device gradually adjusts the output of the inverters until electricity generated from the photovoltaic voltage is always in dynamic match with a load; the reverse-power is enabled not to exceed the set value always, the total photovoltaic output power is enabled to be always smaller than but close to the consumed power of the load, and the utilization efficiency of the photovoltaic resource is enable to achieve the best; and smooth and continuous control is carried out on the output power of the inverter, the contradiction between the number of connecting point switches and the control precision is completely solved, and the control effect and safe operational performance are fundamentally improved in comparison with those of the traditional opening loop control.

The invention relates to a motor driving system for a vehicle bidirectional quasi-Z-source inverter. The motor driving system comprises a speed regulation control module, a sensor unit, and a power supply module, a bidirectional quasi-Z-source preceding-stage passive network, a three-phase bridge type inverter and a motor which are connected in sequence, wherein the bidirectional quasi-Z-source preceding-stage passive network and the three-phase bridge type inverter form the bidirectional quasi-Z-source inverter; the speed regulation control module is connected with the sensor unit and the bidirectional quasi-Z-source inverter separately; and the bidirectional quasi-Z-source preceding-stage passive network comprises inductors L1 and L2, capacitors C1 and C2, an IGBT switch tube S7 and a diode D7. Compared with the prior art, the bidirectional quasi-Z-source inverter system established by the invention, taken as the single-stage inverter system, can replace the two-stage conversion DC/DC and DC/AC conversion in the conventional electric driving field to avoid voltage fluctuation of the battery pack and maintain the stable and adjustable direct bus voltage; and in addition, the problem of dead time existing in the conventional inverter is prevented, so that the output voltage distortion can be lowered, and the torque pulsation and electromagnetic noises can be reduced.

The invention discloses a voltage and current control method and system of an extra-high voltage DC transmission system. According to the method, a fixed pole voltage control mode is adopted by a valve group at an inversion side during running of a DC dual-valve group, and a control object is DC voltage of a pole; fixed valve group voltage control is adopted by another valve group for only controlling the voltages of the two ends of the valve group; fixed pole current control is adopted by a valve group at a rectification side, and the control object is the DC current of the pole; fixed valve group voltage control is adopted by another valve group for only controlling the voltages of the two ends of the valve group; and when pole current control is transferred to the inversion side from the rectification side in a certain running condition of DC, the valve group originally employing fixed pole current control at the rectification side is switched to fixed pole voltage control, the valve group originally employing fixed pole voltage control at the inversion side is switched to fixed pole current control. The invention also discloses a voltage and current control system of the extra-high voltage DC transmission system. With the adoption of the method and the system, the problem of stable voltage and current control during the running of the dual-valve group can be solved.

A differential switch circuit includes a first differential switch basic circuit (1) and a second differential switch basic circuit (2). The first differential switch basic circuit (1) has a first common source node (N1) shared by a plurality of transistors (TP121 and TP122), and the second differential switch basic circuit (2) has a second common source node (N2) shared by a plurality of transistors (TP131 and TP132). The first common source node (N1) and the second common source node (N2) are alternately reset to a predetermined voltage in each clock cycle.

The invention relates to the technical field of hybrid electric vehicles, in particular to a power distribution system and method of a hybrid electric vehicle. The system comprises a controller, an isolating switch, a power distribution control module, a high-voltage power source power distribution module connected with a first wiring contact of the isolating switch, and a low-voltage power sourceconnected with a second wiring contact of the isolating switch, wherein the isolating switch and the power distribution control module are connected with the controller. The high-voltage power sourcepower distribution module is used for being connected with a starter of the hybrid electric vehicle through the isolating switch so as to supply power to the starter. The low-voltage power source isused for supplying power to the starter connected with the low-voltage power source in series. The power distribution control module is used for obtaining working condition information of the hybrid electric vehicle and controlling the isolating switch to be turned on and off on the basis of the working condition information. Through reasonable power distribution, it is guaranteed that the voltageof the whole vehicle is stable, the fault of a blank screen of an instrument or the stall of an engine due to the insufficient power or the start voltage drop is prevented, and the operation stability of the hybrid electric vehicle can be improved.

The invention discloses a novel electric system reactive power compensation system. The novel electric system reactive power compensation system comprises a sampling detection circuit, an intelligent terminal, a compensation controller, a switching control circuit and a reactive compensation unit. The input end of the sampling detection circuit is connected with a three-phase power grid. The output end of the sampling detection circuit is connected with an intelligent terminal. The intelligent terminal is connected with the compensation controller. The compensation controller is connected with the switching control circuit. The switching control circuit is connected with the reactive compensation unit. According to current sampling detection in a sampling detection circuit power grid, the switching control circuit is controlled according to a detection result, a capacitor is switched on or switched off according to certain rules, reactive compensation is performed on the three-phase power grid, automatic real-time compensation for reactive power is achieved, the power supply voltage quality is improved, and the problem that due to the fact that other two-phase under-compensation or over-compensation is caused by existing current single-phase sampling detection, voltage fluctuations of rear-end electric consumption are caused is solved.

The invention discloses an air conditioner and a method and a device for controlling the starting of a compressor of the air conditioner. The method for controlling the starting of the compressor of the air conditioner comprises the following steps of controlling the first compressor of a plurality of compressors of the air conditioner to start; starting timing when the first compressor is started, and obtaining the timing period; when the timing period reaches the preset time interval, obtaining the output power of the air conditioner; comparing the output power and the demand power of the air conditioner; when the output power is lower than the demand power, controlling the second compressor to start, wherein the second compressor is one of the multiple compressors and different from the first compressor. The method has the advantages that the problem of overlong starting time interval of the compressor in the prior art is solved, and the effects of shortening the starting time interval of the air conditioner and improving the energy modulation efficiency of the air conditioner are realized.

A vehicle control apparatus comprises an engine, a starter, an accessory battery, and a high-voltage battery. The vehicle control apparatus is equipped with a DC-DC converter that is connected between the accessory battery and the high-voltage battery, a capacitor that is connected to a circuit on a side of the high-voltage battery, a high-voltage battery determination portion, and a startup control portion. The startup control portion executes power boost-startup control, whereby an output voltage of the accessory battery is boosted by the DC-DC converter, the capacitor is charged with necessary electrical energy for starting the engine by using an output voltage of the DC-DC converter, and the starter is driven to start the engine by using the electrical energy charged in the capacitor.

The invention discloses a switch control power supply circuit, which belongs to a power supply circuit and comprises a power supply input module, a charging module, a storage battery, a switch control module and a power supply output module. In the switch control module, the anode of a diode D1 is connected with the power supply input module and the power supply output module, while the cathode is connected with one end of a resistor R3, the base electrodes of a triode Q1 and a triode Q2 and the third pin of a control switch; the other end of the resistor R3 and the collector electrode of the triode Q1 are connected with the anode of the storage battery and the charging module; the emitting electrode of the triode Q1 is connected with the emitting electrode of the triode Q2; and the collector electrode of the triode Q2 is connected with the first pin of the control switch and the power supply output module; and the second pin of the control switch is connected with one end of a resistor R6 and the other end of the resistor R6 is grounded. The circuit avoids the influences of the synchronous charging and power supply of the storage battery on the service life of the storage battery. The designed switch control module avoids voltage fluctuation caused by an overlong power supply line.