53 results about "Phase balancing" patented technology

The invention discloses a three-core photoelectric composite submarine cable with 220kV rated voltage. The cable is characterized by comprising an outer layer, an armor layer and a lining layer which are distributed from outside to inside in turn, wherein three electrical units in which every two units are externally tangential to each other are arranged in the lining layer; a plurality of filling units are filled in three gaps which are enclosed by the electrical units and the lining layer; the three electrical units and all the filling units are stranded into a submarine cable main core part; a gluing cloth tape is lapped outside the stranded submarine cable main core part; and at least one of all the filling units is an optical unit, and the rest filling units are filling ropes. The invention has the advantages that: the three-core photoelectric composite submarine cable with the 220kV rated voltage has a balanced phase during use, does not have requirements on armoring materials, can prevent the magnetic loss of the armor layer and improves the effective utilization rate of power; and the occupied sea area is greatly reduced compared with that of a single-core submarine cable with the same specification.

Provided are an apparatus and method for load-balancing of a three-phase electric power distribution system having a multi-phase feeder, including obtaining topology information of the feeder identifying supply points for customer loads and feeder sections between the supply points, obtaining customer information that includes peak customer load at each of the points between each of the feeder sections, performing a phase balancing analysis, and recommending phase assignment at the customer load supply points.

The invention discloses a low voltage three-phase load balancing control method based on the on-load commutation technology. According to the method, each outgoing topology structure at a low voltage side of a distribution transformer on an outgoing wire is taken as a model, a control load capacity and a switch position of a commutation switch on the outgoing wire are acquired, a three-phase load unbalancing degree is detected and calculated in real time, if the three-phase load unbalancing degree surpasses a given value, an adjustment-needing load is calculated through a mean value iterative method, a motion-needing commutation switch number and a commutation switch adjustment phase sequence are acquired through utilizing the multi-target optimization principle, and three-phase load balancing is realized. According to the method, factors such as the switch motion frequency and the three-phase load unbalancing degree are fully considered, when the three-phase load unbalancing degree is guaranteed to reach a standard value scope, the smallest switch motion frequency and the lowest commutation cost are realized, moreover, uninterrupted user power supply requirements are realized during load transfer, namely the on-load commutation technology.

A method for improving phase balance in a three-phase power system, such as a three-phase system feeding Single Wire Earth Return distribution networks. The inventive system can take power from a suitable source—including the three-phase distribution itself—and feed it to a “weaker” phase to improve balance. In addition, the system can store energy taken from the three-phase power system during off-peak periods and use this to boost a weaker phase during periods of phase imbalance. The inventive system preferably uses an organic Rankine cycle heat engine to extract stored thermal energy and use it to boost a weak phase or phases. The organic Rankine cycle heat engine may also take power from renewable sources such as solar collectors.

The invention provides a control device and a method for three-phase unbalance and reactive power compensation. The control device comprises a three-phase switch control circuit, a filter module and a current sampling module, wherein the three-phase switch control circuit is connected to the power grid via the filter module; the three-phase switch control circuit and the filter module are connected onto A, B, C of a three-phase load and an N wire; and the three-phase output current of the three-phase load is respectively connected onto the filter module via the current sampling module. The three-phase output current is controlled through a loop of the three-phase switch control circuit, the sizes of each negative-sequence component instantaneous value and each zero-sequence component instantaneous value separated from the outputted three-phase inductor current are the same as those separated by the A, B, C three-phase output current at the three-phase load side but the directions are opposite, A, B, C three phases of current of the power grid are balanced, and the purposes of quick response, accurate three-phase unbalanced current dynamic compensation and reactive power compensation are realized.

The present invention relates to a power testing facility system of a train and a testing method using the same. In the present invention, there are provided a test bed for engaging a testing object, a DC power facility formed of a converter transformer and DC power converter, an AC power facility formed of a phase balancing apparatus, a voltage regulating transformer, and a power factor improving apparatus, a load facility formed of an induction generator and a bi-directional inverter, a measuring apparatus for measuring various characteristics of a propulsion apparatus, and a control apparatus for controlling the entire system. With the above elements, it is possible to implement a type test, a combination test and a train operation simulation test using a facility system adapted to test a power of a train. When selecting an instrument installed in a train, it is implement a desired reliability by testing a previously fabricated product. The facility is economically operated, and an operation cost is minimized. An easier maintenance is implemented. An electrical energy may be restored using a bi-directional inverter. A power loss is decreased. It is possible to prevent an indoor temperature increase.

The invention discloses an L-waveband miniature multilayer low-temperature co-firing ceramic balance filter. The L-waveband miniature multilayer low-temperature co-firing ceramic balance filter structurally and mainly comprises one input electrode, two output electrodes, two protective layers, two layers of strip lines, two layers of capacitor plates and four layers of metal shield plates. A balance output filter converted in different frequency, different pass-band width and different impedance can be designed by optimizing the two layers of coupling strip lines and a grounding capacitor, and functions of the balance output filter are equivalent to combined functions of one filter and one Balun. Compared with traditional multiple-layer balance filters, the L-waveband miniature multilayer low-temperature co-firing ceramic balance filter has the advantages of being simple in structure, small in size, prone to batch production and high in phase balance degree and amplitude balance degree.

The invention discloses a vacuum degree on-line monitor of a vacuum circuit breaker based on pulse discharge detection, which is realized by the following steps: weak pulse discharge signals generated by decrease of vacuum degree in the vacuum circuit breaker are detected by a field measurement probe arranged under the vacuum circuit breaker; high speed analog / digital (A / D) conversion is carried out on data related to partial discharge through transmission channels as well as a corresponding filter device, an applicator and a converter to obtain three-phase fundamental waves and high frequency signals; the three-phase fundamental waves are subjected to balance operation to obtain relative changes of peripheral fields to correspond to changes of vacuum degree, and the high frequency signals correspond to partial discharge signals to reflect the changes of vacuum degree; the processed fundamental wave signals have no noise jamming, and interphase interference can be eliminated by carrying out simple phase balance movement on the processed fundamental wave signals; and the pulse signal strength of the partial discharge signals are bigger and bigger along with the decrease of the vacuum degree as the partial discharge signals are converted into energy signals. Therefore, the strength of direct current signals and the strength of high frequency signals can be utilized as double criterions for the decrease of the vacuum degree of the circuit breaker, thus the monitor has high sensitivity on on-line monitoring.

A moving beam type machine tool is disclosed, having a dynamic phase balancing weight set and a spindle saddle. The spindle saddle has at least one X-axis location feedback device. When the spindle saddle along the X-axis traverse, the at least one X-axis location feedback device is able to locate the spindle saddle and inform a controlling unit. The controlling unit changes the output pressure of the dynamic phase balancing weight set depending on the location of the spindle saddle, so that a crossbeam is able to maintain in a balancing state. The moving beam type machine tool is able to increase accurate, sensitivity of pressure response, withstanding weight and balancing state.

Aspects extend to methods, systems, and computer program products for balancing input phases across server rack power supplies. A rack manager can monitor individual Alternating Current (AC) phase currents at the rack level. The rack manager knows (or can at least determine) which power supplies are connected to which phase. The rack manager can micro adjust individual PSU output voltages to balance current phases at the rack level. Balancing can occur in response to changed server workloads, hot-unplug of one or more servers, etc. When there is one PSU per server, phase balancing can be accomplished by connecting outputs of power supplies together via busbar or wire. Output voltages of individual power supplies can be adjusted to achieve better phase balancing. Phase imbalance can be corrected by a bus bar or wire carrying enough load to correct phase imbalance.

The invention relates to a method used for adjusting three-phase unbalance of a zone area. According to the method, a three-phase balance adjustment concentrator is mounted beside a distribution part, and a tower pole having access wires is selectively equipped with multiple three-phase balance adjustment switches according to a load situation; the real-time data is analyzed and determined by the three phase balance adjustment concentrator, a distribution transform three-phase load unbalance degree reaches above 15% and continues five minutes, statistics of a combination result of all switch loads on a largest load phase is carried out, an unbalance degree after assumed phase change is calculated, an instruction is emitted to the corresponding switch on the largest load phase after optimal taking, loads are driven by the multiple three-phase balance adjustment switches to realize switching from present phases to target phases without power failure, and thereby three-phase automatic adjustment is realized. Through the method similar to a manual mode, work intensity of onsite workers can be effectively reduced, work efficiency is improved, line loss is reduced, great importance for prolongation of distribution transform service life is realized, and electrical appliances are made to realize safe and reliable operation.

The invention belongs to the field of photovoltaic power generation and particularly relates to a grid-connected photovoltaic power generation system and an automatic phase displacement islanding phenomenon detecting method thereof. On the basis of a traditional slip frequency displacement method, a relation function of an initial phase angle and frequency is re-designed, an adjustable parameter is introduced, and program for judgment of a phase balance point is added. Once the system is switched to the phase balance point, the purpose of jumping out of the phase balance point can be achieved by changing the adjustable parameter in an initial phase angle calculation formula. By means of the method, the problem that the phase balance point cannot be switched out once the system is switched to the phase balance point and accordingly islanding phenomenon detecting failure is caused is solved, and the accuracy of power grid failure detection is greatly improved.

The invention provides a current limiting method for a three-phase unbalance adjusting device. the method comprises the following steps of obtaining three-phase current of load side ABC and phase angle of corresponding synchronization thereof, dq transforming the obtained three-phase current of load side ABC and phase angle of corresponding synchronization thereof based on rotational coordinate tocalculate positive sequence d-axis, q-axis current component and negative sequence d-axis, q-axis current component; 3-phase virtual current is obtain after that positive sequence d-axis and q-axis current component and the negative sequence d-axis and q-axis current components are transformed, and the dynamic and steady-state current limit judgement values are determined according to the three-phase virtual current; A dynamic current limiting judgement value is compared with a first threshold value and a steady-state current limiting judgement value with a second threshold value, and according to the comparison result, a current limiting mode currently entered is determined to be a dynamic current limiting mode or a steady-state current limiting mode. As that invention is implement, thedynamic and steady three-phase unbalanced current regulation can be taken into account at the same time, and the damage of other equipment and the waste of power and resource can be avoided.

The invention relates to a lumped-parameter wideband 180-degree coupler with a harmonic suppression function. The lumped-parameter wideband 180-degree coupler comprises seven capacitors and four inductors, wherein the seven capacitors are connected with three inductors so as to form double loops. Capacitor-inductor pairs are adopted to form resonance units so as to provide transmission zeros, such that the harmonic suppression function can be realized; a first connection point is connected with a first port; a second connection point is connected with a second port; a fourth connection point is connected with a third port; and a third connection point is grounded through one inductor, and therefore, secondary inductive coupling can be realized, and the operating bandwidth of the coupler can be expanded. The lumped-parameter wideband 180-degree coupler of the invention is advantageous in fewer used components, small occupied area and low implementation cost; and the lumped-parameter wideband 180-degree coupler can keep excellent output amplitude balance and phase balance in a very wide frequency range, and has factorable harmonic suppression ability, and is suitable for being used in existing handheld mobile radio frequency wireless communication systems.

Methods, systems, and devices for phase balancing of a plurality of high frequency (HF) power generation units of an HF power supply system. In one aspect, a method includes measuring a first signal related to a first power reflected at a load and arriving at a first HF power generation unit, obtaining at least one first value related to the measured first signal in a system control, adjusting at least one of a frequency or a phase of an output signal of the first HF power generation unit based on the at least one first value and a reference value, measuring a second signal related to a second power reflected at the load and arriving at the first HF power generation unit, obtaining at least one second value related to the measured second signal in the system control, and determining whether a specified event for the first HF power generation unit occurs. The method also includes performing phase balancing of one or more further HF power generation units.

The invention provides a phase balancing unit. The phase balancing unit comprises an input port, a plurality of output ports and a power divider circuit; the power divider circuit comprises a main circuit connected to the input port and a plurality of output branches which are connected to the main circuit and are connected to the output ports in one-to-one correspondence; and at least one output branch is provided with a coupling transmission line for changing a signal phase. The coupling transmission line is arranged on at least one output branch of the power divider circuit, which changes phase delay lengths of different frequency bands and achieves a goal that phase discrete type from the input port to each output port is improved in a certain frequency band phase. Besides, the invention also relates to a power divider circuit phase balancing device adopting the phase balancing unit.

A detection apparatus with a self-test is presented. A detection apparatus such as a cable locator has an array of sensors in the form of ferrite antennas to detect an electromagnetic field produced by an object such as a buried cable. The signals are amplified, digitized and fed to a processing unit that outputs a detection signal to a display to indicate the detection of a cable. A programmable signal generator outputs a self-test signal via a voltage-current converter that is used to check the balance between the sensors. The self-test signal is directly coupled into each of the sensors through a wired connection and the processing unit uses the self-test signal to accurately determine the magnitude and phase balance of the sensors. The magnitude and phase data may be used to calibrate the instrument, apply data corrections or flag errors.

The invention discloses a two-phase static coordinate system based power control method of a three-phase voltage source type rectifier direct. With the adoption of the method, the active power and thereactive powder output by the system can be directly controlled under a two-phase static coordinate system on the premise that the capacitance and the voltage at the DC side are stable, so that the active powder demand and the reactive powder demand of the system can be rapidly responded; the vector angle information of the voltage of the power grid is not extracted, and the direction fixing of the voltage of the power grid can be accurately realized in case of three-phase unbalancing. The method is applicable to the situation with a three-phase voltage source type rectifier, and the abnormalvariation of the voltage of the power grid can be effectively responded.

The invention provides a three-phase unbalance and reactive power control automatic switching device. The main circuit comprises a switching power supply, a voltage acquisition device, a current acquisition device, a contactor, a circuit breaker, an intelligent capacitor bank and a power electronic device. The intelligent capacitor bank comprises a phase-to-phase compensation capacitor and a phase-to-ground compensation capacitor and comprises multiple sets of capacitance adjusting branches which are connected among the three phases and between the phase and the ground. A composite switch is connected on each branch. The contactor is connected between the intelligent capacitor bank and a bus. The data collected by the current acquisition device and the voltage acquisition device are transmitted to the controller of the main circuit, and the active power and the reactive power of each item are calculated inside the controller and the capacities of the phase-to-phase capacitor bank, thephase-to-ground capacitor bank and the power electronic compensation device which are required to be switched on and off are calculated according to the power magnitude. The accuracy is high and the response speed is fast so that the station area of the distribution network with serious three-phase load imbalance problem can be dynamically controlled and the operation state of the transformer in the station area can be monitored.

The invention presents a three-phase unbalance detection method based on improved S transform, which can improve the detection speed and accuracy of fundamental wave amplitude and phase information and enhance the detection effect of three-phase unbalance of the system. The detection method includes the following steps: sampling real-time signals of the three phases of voltage of a power grid; extracting the fundamental components in the voltage signals through improved S transform to get the vectors (Ua, Ub, Uc) of the three phases of fundamental voltage, wherein the improved S transform refers to that two regulation factors are introduced to the Gaussian window expression of the traditional S transform to form two degrees of freedom so the time-frequency resolution can be flexibly regulated; calculating the positive-sequence, negative-sequence and zero-sequence components (Up, Un, U0) of three phases of fundamental voltage through a symmetrical component method according to the vectors (Ua, Ub, Uc) of the three phases of fundamental voltage; and calculating the system unbalance according to the positive-sequence, negative-sequence and zero-sequence components (Up, Un, U0) of three phases of fundamental voltage.

The invention discloses a three-phase load balancing system for a low-voltage power distribution network. The three-phase load balancing system comprises a main control station and multiple phase commutation devices; the main control station tries to connect the to-be-connected phase commutation devices into the power distribution network, if a phase enabling the load of the power distribution network to be balanced exists, the phase is taken as a target connection phase; otherwise, the to-be-connected phase commutation device tries to be connected into three phases of the power distribution network sequentially, in order to enable the load of the power distribution network to be balanced, the phase commutation devices, not supplying power to load devices with built-in nastic movement parts, of the power distribution network are identified, a trial connection phase selects the phase commutation devices which are identified firstly and then selects the phase commutation devices which are not identified if the phase commutation devices which are identified are not enough to enable the load of the power distribution network to be balanced, and the trial connection phase selecting the least phase commutation devices which are not identified is determined as the target connection phase; and the to-be-connected phase commutation device is controlled to be connected into the target connection phase. The condition that the load of the power distribution network is unbalanced due to connection of the phase commutation devices is not prone to occur, a little number of phase commutation devices need phase switching, and the load devices can keep operating stably.

The invention provides a KIDs detector noise test circuit based on an active quadrature mixer and a test method thereof. The test circuit is characterized in that the test circuit comprises a frequency synthesis source, a directional coupler, a KIDs detector readout circuit module, an adjustable phase shifter, an active mixing circuit module, a filter circuit module, a data acquisition card, a control computer and the like. The test circuit takes a broadband Gilbert double-balance active quadrature mixer circuit structure as a core module, can complete noise test work on KIDs detector chips, and has excellent amplitude / phase balance degree and port isolation degree. The parasitic direct current bias voltage generated by a frequency output port is weak, the measurement is accurate, the mixer does not need to be separately calibrated, the measurement process is simplified, and the power level of the frequency synthesis source is reduced at the same time.

The invention discloses a bandwidth phase equalization method suitable for an array transponder. The phase unbalance in a full-bandwidth of a multi-channel active single-machine in a multi-channel system link or system of the array transponder is equalized through the dispersion characteristic of a transmission line, thereby achieving a control aim of phase consistency in the full-work bandwidth of the array transponder. The method disclosed by the invention is mainly used for effective load of a static orbit mobile communication satellite using the array transponder. Through the method provided by the invention, the requirement on phase consistency in the multi-channel full-work bandwidth by the array transponder can be realized, the power integration capacity, the beam forming precisionand like main performance indexes related to the phase consistency of the array transponder are improved, and the performance of the array transponder is promoted.

A phase balancing system includes a load forecasting module, a phase unbalance identification module and a demand response module. The load forecasting module determines a load forecast for the distribution system for the period of interest and the phase unbalance identification module determines voltage unbalance on the distribution system for the period of interest. The demand response module estimates an available demand response on the distribution system for the period of interest and allocates an optimized demand response from the available demand response to minimize the voltage unbalance on the distribution system for the period of interest.

The invention discloses a novel broadband high-balance-degree balun which comprises a first-stage balun for converting an unbalanced signal into a balanced signal, and a second-stage balun of which the input end is connected with the output end of the first-stage balun and which is used for improving the balance degree of an output signal of the first-stage balun, and a phase compensation capacitor is connected between the first-stage balun and the second-stage balun. By arranging the first-stage balun and the second-stage balun, the unbalanced signal is converted into a differential signal through the first-stage balun, and then the differential signal generated by the first-stage balun is improved through the second-stage balun so that the phase balance degree and the amplitude balance degree of the differential signal are improved; therefore, the phase difference of the finally output differential signals is closer to 180 degrees, and the amplitudes tend to be equal. The structure of the invention is suitable for various circuit applications, such as frequency mixers, duplexers and the like. In addition, based on the improved balun structure, a high-performance mixer, a high-performance duplexer and the like based on semiconductor material systems such as a silicon substrate, germanium-silicon, gallium arsenide and gallium nitride can be designed.

The invention relates to an alternating current charging pile three-phase balance method and system. The method comprises the following steps: periodically calling a current effective value, collectedby each charging pile in a charging pile network in real time, of a current connected phase sequence; according to the current effective value of the current connected phase sequence of each chargingpile and the current charging pile network environment, performing split-phase calculation on the three-phase phase sequence of each charging pile based on a preset algorithm to obtain the three-phase unbalance degree of the charging pile network; judging whether balance switching needs to be executed or not according to the three-phase unbalance degree of each charging pile and the national standard or other standard requirements; if balance switching needs to be executed, selecting a corresponding balance switching scheme based on a balance algorithm to guarantee that the balance switchingscheme is optimal; and issuing a phase sequence switching instruction to the charging pile needing to be switched according to the selected balance switching scheme, and enabling the charging pile toexecute switching according to the instruction. Due to the fact that the charging piles in the charging pile network are subjected to dynamic balance periodically, the charging piles in the charging pile network can keep three-phase balance all the time under the execution of the dynamic balance strategy.

The invention discloses a three-phase load balancing system of main and branch lines of a distribution network. The system is composed of a main controller and a plurality of branch controllers. The main controller determines a phase adjustment pair and a main adjustment value based on an unbalanced load situation of a main line and selects and adjusts branch lines among all branch lines based onthe phase adjustment pair. All branch controllers mark commutation devices that do not provide power for load devices with built-in magnetic motion parts at the source phases of the adjusted branch lines, needed commutation devices are selected among the marked commutation devices, and then if the marked commutation devices are not sufficient, commutation devices are selected from unmarked commutation devices; and the sum of power loads of the selected commutation device of all adjusted branch lines is equal to the main adjustment value, access phases of the selected commutation devices are controlled to be switched to be target phases, so that loads of the main lines and the branch lines meet a balancing requirement. Therefore, a phenomenon that the load device with the built-in magneticmotion part of the user terminal makes commutation vibration and thus noises are caused is avoided and the system works stably.

The invention relates to a marine three-phase-into-two-phase balancing transformer. The balancing transformer comprises an iron core, a primary side winding and a secondary side winding, wherein the iron core adopts a three-phase columnar shape or a three-phase shell shape; the primary side winding is connected in a triangular manner, consists of three-phase windings AX, BY, and CZ, and the number of turns of the windings is W1; the secondary side winding comprises two parts; the first part comprises A-phase and C-phase windings with the number of turns of W2; the A-phase and C-phase windings are connected in series; the second part comprises a B-phase winding with the number of turns of W3; the relationship of the number of turns of the secondary side winding is as follows: a formula is as shown in the specification. The technological advancement of less number of windings, simple structure of the transformer, and relatively high material utilization ratio is realized; complex impedance matching is not required; and the transformer is easy to produce and manufacture.