The method of controlling the reactive power compensator
(57) Abstract:The essence of the invention: in the compensator containing parallel connected inductive element, a counter-parallel thyristors, capacitor battery and switches compensator capacitor Bank, the capacitor discharge batteries carry a counter-parallel connected thyristors controlled pulses synchronizing with the following frequency L - C circuit formed by the inductance and capacitance of the compensator and the rapid discharge a total current of condenser battery within a few tens of periods of oscillations for different values of L and C circuit that is a few seconds. 2 Il. The invention relates to electronics, in particular for electricity, and can be used in a static reactive power compensator for transmission lines.A known method of controlling the reactive power compensator in which the discharge of condenser battery compensator is performed via the discharge resistors connected parallel to the capacitors of the capacitor battery.The disadvantages of this method are the low reliability because of the large to the E. great cooldown to re-enable the capacitor Bank.A known method of controlling the reactive power compensator, which provides a rapid discharge of the capacitor battery, in which the functions of the network parameters support angle control valves, including their frequency network;
before switching to reduce the current through the switch compensator to the minimum value by the influence of the angle control of the thyristors;
disconnect switch compensator;
since the circuit breaker compensator for discharge of condenser battery include thyristors with its own frequency compensator defined by the parameters L and With the compensator;
measure the voltage level on the capacitor battery;
compare it with the minimum specified value;
if equality disconnect switch capacitor banks
restore the original frequency turn-off thyristors with the desired angle control and include a switch to compensate for Satoru.However, the known method has the lack of reliability of the control compensator of reactive power due to the unreliability of the thyristor control at the discharge condensator is TKE control changing the frequency of the synchronization pulse thyristor control depending on changes of the parameters of the compensator. In addition, the need to measure the voltage on the capacitor battery and comparing the measured value with the set to determine when the end of discharge of condenser battery also reduces the reliability of the compensator control.The aim of the invention is to improve the reliability of compensators due to the formation at the discharge of the capacitor battery of the respective synchronization signals, providing the inclusion of counter-parallel connected thyristors with a variable inductance or capacitance of the compensator.This is achieved by the fact that after the circuit breaker compensator produce launch clock pulse and serves it on the counter-parallel connected thyristors, emerged from the half-wave current at the time of its completion allocate current clock pulse and serves it on the counter-parallel thyristors, etc. to reduce the signal level at the output of the sensor parameter, proportional to the current compensator to a minimum level corresponding to the holding current of the thyristor, so each subsequent half-wave current is started by the previous wave of the current, i.e., the time of occurrence of each of the next half-wave of toklas control thyristors when changing the natural frequency of the compensator, i.e. when you change the parameters L, With compensator, so there is no need in their control and development control changing the frequency of the control pulses of the thyristors when changing the parameters of the compensator, which increases the reliability of the compensator control.In addition, the use of the current signal, allows, in addition to obtaining the required synchronization of the control pulses of the thyristors to provide a rapid discharge of the full current of the capacitor Bank to the minimum level defined by the holding current of the thyristor and eliminates the need to measure the voltage of the capacitor battery, which also increases the reliability of the control capacitor.In Fig. 1 shows one example of the use of the method that explains the device of Fig. 2 is a timing diagram explaining the operation of the device.The device consists of connected to the network through the switch 1 of the compensator 2, consisting of a series connected inductive element 3 and the counter-parallel connected thyristors 4 and is connected thereto in parallel through the switch 5 capacitor Bank 6, controller 7 connected to the network through the sensor 8 parameter Setty which are connected, respectively, by differentiating the elements 12 and 13 to the 1-th and 2-th inputs of the element IL 14, 3-d input of which is connected through a differentiating element 15 and block 16 of the contact switch 1 to the source voltage E, the 4th input of which is connected through the block 17 of the contacts of the switch 1 to the output of the controller 7, the inputs of the Comparators 10 and 11 are connected through the block 18 of the contacts of the switch 1 to the output of the current sensor 9, the output of the OR element 14 is connected to the input of the amplifier-shaper 19 pulses, the output of which is connected with the control electrodes of the counter-parallel connected thyristors 4, either directly or through the host 20 galvanic isolation, for example a transformer.The operation of the device is as follows.In the regime of network parameters, such as voltage, switch 1 and switch 5 is turned on. When the switch 1 in the blocks 16, 18 contacts are open, the unit 17 contacts are closed and the current through the inductive element 3 is determined by the synchronization pulses appearing on the output of the controller 7 according to the signals of the sensor 8 voltage. The current through the capacitor battery 6 is determined by the value of its capacitance and the voltage whose period is TS. Before disconnecting capacitor Bank 6 the current through the inductive element set according to the signal controller with many brand is>produce the circuit breaker 1. Through the time corresponding to the delay time tCat the moment of time t1opened in block 17 contacts 17 1 and closed contacts in blocks 16 and 18 of the switch 1. When the circuit in block 16 of the contacts on the output of the differentiating element 15 appears starting sync pulse U 15 passing through the element IL 14 (U 14), and after amplification in the amplifier-shaper 19 pulses (U 19) is supplied to the control electrodes of the meetings - but-parallel connected thyristors, ensuring their inclusion on the voltage UKBcapacitors battery 6. You receive 1-I positive half-wave current i, which is the output of the sensor 9 is supplied through the closed contacts blocks 18 to the input of the Comparators 10 and 11, causing the switching comparator 10. At the end of the positive half-wave current of the differential voltage levels on the output of the comparator 10 is differentiated and differentiating element 12 and the appearing of the current clock pulse U 12 is fed through the OR element 14 (U 14) on the amplifier-shaper pulse 19 (U 19) and then through the node galvanic isolation 20 on the control electrodes of the thyristors 40 ensuring their inclusion and the appearance of a negative half-wave current, which causes the switching comparefiletime differentiating elements 13 and introduced the current clock pulse U 13 is fed through the OR element 14 (U 14) on the amplifier-shaper pulse 19 (U 19) and then through node 20 galvanic isolation on the control electrodes of the thyristors 4, ensuring their inclusion and the appearance of the positive half-wave current, which causes the switching comparator 10, and so on, Then the processes are similar up until the voltage UKBon the capacitor battery 6 decreases to a minimum level UKBminthat is until the voltage at which the current Iminthrough the thyristors 4 reaches the value of holding current Ibeatsand the thyristors are not included (time t2). Then restore the original the switching frequency of the thyristors with the desired angle control and include switch compensator.The oscillatory discharge of a condenser battery 6 to the inductive element 3 through a counter-parallel connected thyristors 4, followed by the frequency f = defined by the parameters L, With compensator provides current pulses U 14 formed on the moments of the end of the half-wave current. Therefore, the frequency of the pulse shaping control thyristors at the discharge of the capacitor battery is always equal to the natural frequency ftocircuit formed by the capacitor Bank 6 and the inductive element 3 regardless of changes in the parameters of the circuit (the value of the capacitance of condenser battery 6 and the inductance value of the inductive is Atara with tunable frequency and control systems, regulating the repetition frequency of the clock generator and their phase position relative to the voltage on the thyristor, which increases the reliability of the compensator control.The formation of the current pulses of the half-wave current also allows you to ensure the maximum inclusion of thyristors with a minimum voltage on the capacitor battery, because to ensure complete discharge of the capacitor battery without direct measurement of the voltage on the capacitor battery, which also increases the reliability of the control joints. The method of controlling the REACTIVE POWER COMPENSATOR, connected to the network through the switch and contains parallel connected adjustable in opposite parallel connected thyristors inductive element and through the switch capacitor battery, in which the functions of the network parameters support angle control of the thyristors, including their frequency AC power, and produce switching of the switches so that before switching to reduce the current through the switch compensator to a minimum by the influence of the angle of thyristor control, disconnect switch compensator off and include tire lower signal strength parameter to a minimum level, then restore the original the switching frequency of the thyristors with the desired angle control and include switch compensator and switch capacitor battery, characterized in that after the circuit breaker compensator form the launch clock pulse and serves it on a counter-parallel connected thyristors, at the end of each half-wave discharge current of condenser battery form the synchronization signals and applying them to the said thyristors to reduce the signal level parameter, proportional to the current compensator, to a minimum level corresponding to the holding current of the thyristor.
FIELD: electrical engineering; energy storage, motor starting gear, ac networks.
SUBSTANCE: polarized capacitors or electrochemical batteries are used in standard ac circuits as polarized electrical charge storage devices with new circuit pattern. In one of alternatives opposing-series configuration of first and second polarized devices is used in ac network to improve its operating conditions. At least one dc power supply is provided to keep polarized devices shifted in forward direction when ac signal arrives at them. This ac signal is applied to devices connected in series opposition to excite ac load. These devices are sufficiently shifted by at least one dc voltage supply so that they remain displaced in forward direction upon connection to ac signal.
EFFECT: enhanced effectiveness and economic efficiency of polarized charge storage devices in all their applications.
64 cl, 32 dwg
FIELD: electrical engineering; correction of instant-power passive components associated with characteristics features of load.
SUBSTANCE: proposed corrector uses circuit arrangement of single-phase voltage inverter in the form of transistor bridge incorporating inverted diodes with storage capacitor connected across two diagonally opposite dc terminals and two diagonally opposite ac terminals connected through choke to supply mains in parallel with load; choke has sectionalized coil, that is it is made of two sections with output lead in-between; corrector is provided with newly introduced switch built around two thyristors and used to connect one section of choke coil during discharge of storage capacitor and both sections during its charge.
EFFECT: enlarged adjustment range of instant-power passive components; enhanced reliability of corrector.
1 cl, 2 dwg
FIELD: reactive power correction in three-phase loads.
SUBSTANCE: proposed reactive-power corrector has three-phase transformer, three single-phase inverters with control systems, rectifier, three single-phase current transformers, potential transformer, three single-phase reactive-current sensors, three voltage sensors, three comparison gates, and load; in addition it is provided with newly introduced unit of off-line voltage inverters, active and reactive power computing unit, active and reactive power ac component computing unit, desired current computing unit, off-line voltage inverter control unit, and current transformers of off-line voltage inverters.
EFFECT: enhanced mean power factor of enterprises, reduced maintenance charges.
1 cl, 1 dwg
FIELD: electrical engineering.
SUBSTANCE: proposed device tat can be used to raise efficiency of electrical energy consumption due to relieving power supply mains of reactive currents has three-phase diode bridge connected to supply mains through three reactors; connected at dc output of this diode bridge through isolating diodes are three storage capacitors. Device also has bridge inverter built around six transistors connected through their outputs to ac input of diode bridge and three additional transistors connecting dc input of inverter to storage capacitors. Transistor control system functions to convert signals arriving from outputs of voltage sensors across load, load and supply mains current sensors, and to generate thyristor control signals so that source automatically generates correction currents equal to reactive currents consumed by load, and only resistive component of load currents is consumed from supply mains.
EFFECT: reduced mass and size of device, ability of generating sine-wave corrective currents.
1 cl, 2 dwg
FIELD: electrical engineering; power factor correction for ac electric locomotive.
SUBSTANCE: reactive power correcting device has traction transformer, electric-locomotive rectifying converter with traction motor connected thereto, two reactive-power sources, supply-mains mode sensor, and switching unit; newly introduced are also two switching members, each incorporating thyristor switch, voltage sensor built around thyristors, and thyristor-switch control pulse shaper, as well as two resistors; thyristor switches are connected in series with first and second reactive power sources and resistors are connected in parallel with capacitors of respective reactive-power sources.
EFFECT: enhanced power factor due to improved waveform of output current and more complete correction of input-current reactive component under various operating conditions.
1 cl, 1 dwg
FIELD: power engineering; automatic tuning of capacitive current correction in network incorporating plunger-type arc-control reactor.
SUBSTANCE: proposed device for automatic tuning of adjustable-gap arc-control reactor correction has motor control unit connected to correction maladjustment recording unit and to control input of mentioned arc-control reactor provided with motor for air gap adjustment. Motor control unit has first contactor control unit connected through first auxiliary contact to correction maladjustment recording unit, second contactor control coil connected through second auxiliary contact to correction maladjustment recording unit, and third contactor control coil. First and second power contacts are connected to control input of adjustable-gap arc-control reactor; third and fourth auxiliary contacts are connected to short-pulse shaper. Final relay is connected to short-pulse shaper and its contact is inserted in third control coil of contactor. Fifth and sixth auxiliary contacts are connected in series with first contactor control coil and with second contactor control coil, respectively. Motor control unit also has rectifier bridge connected through limiting resistor and third power contact to control input of mentioned reactor incorporating air gap adjusting motor.
EFFECT: enhanced precision of reactor tuning in resonance with network capacitance.
1 cl, 2 dwg
FIELD: regulation and reactive power correction in power systems; inverters for high-voltage frequency-controlled electric drives.
SUBSTANCE: proposed converter is built around combined circuit arrangement incorporating three-phase bridge circuit of voltage inverter (with series-interconnected semiconductor devices of IGCT, IGBT, and other types) with one or more series-interconnected single-phase bridge voltage converters (whose semiconductor devices are not interconnected in series)connected to each of its phase outputs. All change-over operations are made in three-phase bridge circuit whose arms form valves with series-interconnected semiconductor devices and which forms output voltage base of converter at low frequency (such as that equal to supply mains frequency). Bridge arms incorporating series-interconnected semiconductor devices having different on/off delay times are changed over by means of switching circuits specially inserted in circuit.
EFFECT: enhanced reliability reduced power loss in building converter combined circuit, reduced dynamic loss in semiconductor devices.
3 cl, 9 dwg
FIELD: electric engineering, possible use for engineering of traction electric engines of electrically driven train.
SUBSTANCE: station for testing electric engines has transformer, controllable rectifier, inverter, engine, generator, first and second smoothing reactors, connecting shaft, voltage indicator, first and second current indicators, device for calculating input active current, first and second comparison element. Proportional-integral adjuster, pulse-duration modulator, autonomous voltage transformer and source of reactive power in form of a capacitor. Utilization of station for testing electric engines allows to increase value of power coefficient up to 0,994, and during testing of, for example, electric engine NB418 K6 of electrically driven train current consumed from network is decreased to 5-7 A.
EFFECT: increased energy coefficients due to increase of value of power coefficient by improving form of network current and approach of its phase to network voltage during substantial decrease of energy consumption.
FIELD: power engineering; reactive power correction.
SUBSTANCE: proposed method for controlling reactive power correction device incorporating thyristor-reactor group, higher-harmonic capacitor-bank filters, and reactive-power static condenser built around fully controllable diodes includes measurement of voltage U across ac buses, its comparison with Umax and Umin settings, generation of control signals, and generation of harmonics in static condenser current in phase opposition to current harmonics of thyristor-reactor group detected during analysis.
EFFECT: twice as low power of thyristor-reactor group, enhanced efficiency of input reactive power control and higher harmonic filtration.
1 cl, 1 dwg
FIELD: electric engineering, on railroad train of one-phased alternating current with zone-phased adjustment, acting as means for increasing power coefficient.
SUBSTANCE: reactive power compensator is connected in turns to one of several sections of secondary winding of traction transformer, powering appropriate shoulders of rectification-inversion transformer. Depending on value of reactive power of circuit, sections of reactive power source are connected to power source. Device for realization of proposed method for controlling reactive power compensator, additionally contains keys, which through reactive power compensator are connected to sections of secondary winding of traction transformer, keys control block, operation mode set-point device, indicators of voltage and current, calculating-measuring block.
EFFECT: compensation of reactive power, consumed by electric locomotive, and decreased electric energy consumption.