47results about How to "Does not generate harmonics" patented technology

The invention relates to an electric stepless speed-variable dual-power wind generator, wherein the electric stepless speed changer (2) comprises a stator (2.1), an outer rotor (2.2), an inner rotor (2.3), and a sliding ring (2.4). The wind turbine (1) via an input axle (6) is connected with the rotor (2.3), the sliding ring (2.4) is mounted on the axle (6), the circumference of the rotor (2.3) is disposed with the rotor (2.2), the circumference of the rotor (2.2) is disposed with the stator (2.1) which via an output axle (7) is connected to a generator (3), the rotor (2.3) is disposed with a multi-phase winding to connect a first power converter (5) via the sliding ring (2.4) and an electric brush, the stator (2.1) is arranged with a multi-phase winding and connected with a second power converter (4), the first and second power converters (4, 5) are connected with one direct-current power.

The invention discloses a triangular connection type comprehensive compensation system integrated with a cascaded active filter and a reactive compensator. The system comprises triangular connection type N-grade cascaded converters and a three-phase filter inductor connected with each N-grade cascaded converter; triangular connection type thyristor reactors and star-shaped connection type thyristors are used for switching the reactive compensator composed of fixed capacitors; and the triangular connection type N-grade cascaded converters and the reactive compensator are connected in parallel between a connection node and a ground node of an input power grid voltage and a load. According to the system provided by the invention, reactive power and harmonic current in a medium-voltage power grid are subjected to dynamic compensation and the efficiency of the power grid is improved; when the system is used for compensating, the system has no negative influences on the power grid, and has advantages of stable system, simple structure, strong stability and flexibility in compensation.

The invention discloses a superconducting motor with ultra-low loss, which comprises an enclosure, a stator and a rotor, wherein the rotor is in an iron-core-free structure and mainly comprises a pole shoe, a rotor spider and a hollow rotating shaft; the pole shoe is wound with an exciting winding; the exciting winding is a superconducting coil; for the stator, a cooling tube is arranged in each stator slot based on the traditional structure; the enclosure comprises a housing; a spiraltron is wound on the outer side of the housing; a heat-proof radiation layer is arranged on a tooth surface of the stator; and cooling media are charged into the spiraltron, the cooling tubes, collecting tubes and the hollow rotating shaft. The superconducting motor with the ultra-low loss is very low in motor loss; the efficiency of the superconducting motor can reach above 99%; no dewar is arranged in an air gap; and the small air gap becomes possible; the motor is low in heat leakage and high in power density; and the refrigeration cost is low.

The invention discloses a dynamic idle compensation device for controlling high voltage based on an IGBT (Insulated Gate Bipolar Translator), comprising an idle compensation branch which is connected with a power transmission power grid in parallel and further comprising a reactance transformer, wherein the primary winding side of the reactance transformer is connected with two ends of the idle compensation branch in parallel; the secondary winding side of the reactance transformer is connected with a direct-current power supply through an IGBT inverter; and a control end of the IGBT inverter is connected with a control circuit for triggering the control pulse of the IGBT inverter. Alternating-current current is injected into the secondary winding side of the reactance transformer and a main controller is used for comparing a target power factor with a current power factor obtained by calculating collected voltage and current data; a control pulse PWM (Pulse-Width Modulation) waveform for triggering the IGBT inverter is adjusted through closed ring control, so that a current amplitude injected into the secondary winding side of the reactance transformer is changed, the continuous adjustment of a main magnetic flow of an electric transformer is realized, and then the continuous adjustment of the primary winding side of the reactance transformer is realized, and the stepless continuous adjustment of the capacitance and the inductance of the power transmission power grid is realized.

The invention provides a high-voltage reactive power automatic compensation device, belongs to the technical field of reactive power compensation of a power grid, and solves the problems of low power quality and poor stability of the power grid when the conventional device is used in a 35KV transformer substation. The high-voltage reactive power automatic compensation device comprises a vacuum circuit breaker, a switching capacitor group, a controller, a current sensor and a voltage sensor, wherein the switching capacitor group is used for changing a power factor; the wire inlet side of the vacuum circuit breaker is connected with a three-phase generatrix; the wire outlet side of the vacuum circuit breaker is connected in series with a reactor and an intelligent switching switch in sequence; the intelligent switching switch is connected with the switching capacitor group; the current sensor is used for detecting the current of each phase of the three-phase generatrix and the voltage sensor is used for detecting the voltage of each phase of the three-phase generatrix; the current sensor and the voltage sensor are both connected with the input end of the controller; and the output end of the controller is connected with the intelligent switching switch. The device does not generate a harmonic wave in use, and is low in loss and high in grid power quality and stability.

The invention relates to an alternating current (AC) stepped controllable single-phase/three-phase shunt reactor, which comprises a main reactor, a graded reactor, a detecting unit and a central control unit, wherein the main reactor is in a single-phase or three-phase form; a primary coil of the main reactor directly accesses a power network, and a secondary coil of the main reactor is connected in parallel with one or more graded reactors, and each graded reactor has a control part for controlling the connection and disconnection of the reactor respectively; the input end of the detecting unit is connected with related parameter information of the power network and the main reactor, and the output end of the detecting unit is connected with the central control unit; the control end of the central control unit is connected with the control part of each graded reactor. In the invention, the graded reactor is designed to be connected in parallel with the secondary coil of the main reactor, so that the regulating capacity range can be in various combinations, the regulation is convenient, and the response speed is fast. The reactor provided by the invention has all the functions and properties of a common reactor, more harmonic waves are isolated, and the influence on the power network is reduced; the short-circuit impedance of the main reactor can be designed to be less than 100%.

The invention relates to the resistance furnace temperature control method technology field and particularly relates to an automatic resistance furnace temperature control method based on a queue model. The method comprises steps that (1), even group division is carried out, all heaters in a single resistance furnace are evenly divided into N groups according to heating power, any group of heaters is connected with a power source through a switch device, and all switch devices are controlled by a controller to realize on and off; (2), the setting temperature inputted from the controller is defined to be Tset, and the actually-measured temperature acquired at the controller is defined to be Tact; (3), the group quantity of heaters needing being switched on or switched off is calculated, when the Tact is smaller than the Tset, the group quantity of heaters needing being switched on is defined to be B, when the Tact is greater than the Tset, the group quantity of heaters needing being switched off is defined to be E; and (4), the heaters are switched on or switched off. Through the method, the temperature of the resistance furnace can be more excellently controlled.

The invention discloses a plug-and-play series power quality compensator and a compensation control method and belongs to the field of power compensators. The plug-and-play series power quality compensator is characterized in that a voltage detection module is used to detect real-time voltage of a load; a voltage is applied to a secondary side of a special transformer via an inverter to generate feedback voltage; the special transformer includes a primary side winding and a secondary side winding, the primary side winding is used as a busbar connected to a power grid, the secondary side winding is tightly stacked in the axial direction and connected with the output end of an inversion control module; the input end of the inversion control module is connected with direct-current side voltage, the control end of the inversion control module is connected to the output end of the voltage detection module, and the inversion control module is used for outputting feedback control voltage forthe secondary side of the special transformer according to a reference voltage signal. The plug-and-play series power quality compensator is simple to connect, has no influence on the structure of a power grid, has flexible control modes and meets the needs of different scenes.

The invention discloses a direct-current side harmonic suppression system and a method for a multi-pulse wave thyristor controllable rectification system, and belongs to the technical field of power electronics. The system and the method solve the problem that the nonlinear characteristic of the existing multi-pulse wave thyristor controllable rectification system induces the direct-current side to generate harmonic wave. A signal processing and controlling circuit processes the received standard triangular wave signal, load loop current signal and vice-side winding current signal, and transmits two generated PWM (Pulse Width Modulation) driving signals to a driving circuit; the driving circuit carries out power amplification to the two received PWM driving signals, outputs the amplified signals to a sixfold frequency multiplication current triangular wave inverter circuit, adjusts the vice-side winding current value of an interphase reactor with vice-side, and enables the vice-side winding current peak value to be 0.5 times as great as the load loop current value through current closed-loop control; in each period, the first zero crossing point which is led to negative value and belongs to the vice-side winding current to be lagged after a voltage starting point alpha of the alternating current input phase A. The direct-current side harmonic suppression system and the method for a multi-pulse wave thyristor controllable rectification system can be applied to the field of high power work.

The invention belongs to a three-phase compensation dynamic reactive power compensation device which comprises electric reactors and capacitors, wherein the electric reactors and the capacitors are connected to an A-phase circuit, a B-phase circuit and a C-phase circuit. The three-phase compensation dynamic reactive power compensation device is characterized in that a high-voltage circuit is respectively connected with two paths of electric reactors through the A-phase circuit, the B-phase circuit and the C-phase circuit led by an automatic switch DK via a contactor or a compound switch, an induction coil of one path of the electric reactors is connected with one pole of a single capacitor CN, and the other pole of the single capacitor CN is connected with a zero line; a terminal T1, a terminal T2 and a terminal T3 of an induction coil of the other path of the electric reactors are connected with terminals of a capacitor bank, a delta connection method is adopted in the capacitor bank, the terminal T1 is connected with one pole of the capacitor C1 and one pole of the capacitor C2, the terminal T2 is connected with the other pole of the capacitor C1 and one pole of the capacitor C3, and the terminal T3 is connected with the other pole of the C2 and the other pole of the capacitor C3. The three-phase compensation dynamic reactive power compensation device is used for dynamic reactive power compensation of an electric power system, minimization of injection power harmonic waves can be achieved by controlling, and compared with a traditional dynamic reactive power compensation device, the three-phase compensation dynamic reactive power compensation device has a more ideal comprehensive property.

A high-voltage sodium lamp is the most commonly used electric light source. The invention discloses a voltage-reducing and power-saving method for the high-voltage sodium lamp, and a voltage transformation type power saver. tests are carried out according to appendix F of GB/T13259-2005, after the high-voltage sodium lamp is lighted on normally, when the voltage is dropped to 190V suddenly, the high-voltage sodium lamp does not light out; the high-voltage sodium lamp can implement voltage-reducing power supply tests; voltage-reducing experimental data from a certain manufacturing plant is as follows: when the power supply voltage is reduced from 220V to 200V, the lamp current is reduced by 6.3% and power is saved by 16.1%; the illuminance, the luminous flux and lighting effect are all lowered; however, the illumination quality (uniformity) late at night is not affected; the voltage transformation type high-voltage sodium lamp power saver mainly comprises a main circuit, a control circuit and a photoelectric controller; the power saver is tested by Hunan Province Measurement and Detection Institute; the test certification number is EQ no. 2009-0756; and the detection conclusion shows that the power of a 70W high-voltage sodium lamp can be saved by 16% under 200V power supply compared with that of the 70W high-voltage sodium lamp under 220V power supply.