Three-phase transformer with voltage regulation under load
(57) Abstract:Usage: in transformers with voltage regulation under load with a relatively large depth of regulation. The technical result consists in the design of the transformer with reduced variations in the voltage level across the range of regulation. This is achieved by alternate use of phase and simultaneous switching modes switching devices of the transformer under load. At the entrance to the zone, regulate the voltage level becomes lower than the voltage level at the beginning of the control range. The mode transition voltage regulation of the transformer phase simultaneously solves the problem of equalizing the voltage level within the entire adjustment range. 1 Il. The invention relates to the field of electrical engineering, namely to transformers with built-in voltage regulation under load with a relatively large depth of regulation, when the requirements of the small variation of the voltage level in the entire control range.Known 3-phase transformer with built-in RPN, starostwo . The disadvantage of the transformer at a great depth regulation and the small size of the stage are a large number of branches (steps) regulating winding and a switching device with a large number of switching positions, and the difference voltage regulation level, reaching, for example, at 50% depth regulation three values on the first and last positions of the regulating winding of the full range.All this complicates and increases the cost of manufacture and reduces its technical level.Known 3-phase transformer with load tap-changer containing a network and in series with it is connected a regulating winding with n stages; three-phase switching device (one for each phase) with position sensors and their output circuits engaged alternately switching phases (ABC) mode .This allows the use of a regulating winding with the number of branches, less three times, and switching devices with three times fewer provisions by obtaining between two adjacent taps of the regulating winding of the three stages of the voltage transformer.The aim of the present invention is to provide a transformer with low variation in voltage level regardless of the position of the switching device of the regulating winding.This goal is achieved by the fact that in three-phase transformer with voltage regulation under load, containing the switching device in phase with position sensors and their output circuits, control circuits "ABOVE" and "BELOW" proposed regulation voltage switching devices to perform using logic elements AND, NOT, and chain position sensors connected to the inputs of the element I1, and the output element I1 to connect with one of the inputs S2, the control circuit ABOVE, BELOW, to connect to the second input I2, the output S2 be connected to the input element and the control circuits "SIMULTANEOUSLY", and the output element is coupled with the control circuits of the switching devices "phases".The necessity and sufficiency of aimogasta logic elements And, NOT, control signals, a switching device and a regulating winding of the transformer allows the specified provisions of the switching devices of the branches of the regulating winding to move from one mode phase control switching device in the mode of simultaneous control.Under such a regime change (regulation) control is an increase in the voltage regulation level, i.e., the passage of the second part of the control range of the transformer will be the speed, three times larger than in phase regulation.Thus, when entering the area of regulation, when the voltage level becomes considerably smaller than the voltage level at the beginning of the control range, the mode transition voltage regulation of the transformer phase simultaneously solves the problem of equalizing the voltage level within the entire adjustment range. Depending on the depth control circuit connection network of the winding position of the switching device, which should work position sensor, can be combined either with the inclusion of the coarse stage, or enable network winding band pereklyuchaem device specified branches of the regulating winding.The drawing shows a diagram of the inventive transformer.Three-phase transformer 1 with voltage regulation under load, the switching device for the phase - 2 with position sensors - 3 with their output circuits 4, 5, 6, they are the same input element 1, the circuit 7, the output of the element 1 and the first input element S2, the control circuit 8, ABOVE, BELOW and to the second input of the element I2, the circuit 9 to the output of the element I2, the input element and the control circuit SIMULTANEOUSLY, the output element is a control circuit of the switching devices of each phase.In the transformer, when the phase regulation voltage level becomes lower than the specified trigger position sensors 3, the appearance of three signals in the circuits 4, 5, 6 at the input of the element I1 provides a signal is received by circuit 7, which is supplied to one of inputs of the element I2, and after the reset command is ABOVE or BELOW the circuit 8 is supplied to the second input of the element I2. The output signal of the circuit 9 of the element I2 through the element does NOT issue a ban phase regulation (PHASES) and the resolution of the signal at the same time, which is the simultaneous switching of the switching device when the voltage regulation. The transition to aerovane voltage throughout the range of more equal levels of voltage.Sources of information
1. J. L. Fisler, R. N. Urmanov, L. M. Pestrava. "Transformer equipment for converting units), Energoizdat, 1989, pp. 51-53.2. The same, page 67. Three-phase transformer with voltage regulation under load, containing the switching device of the branches of the regulating winding in phase with position sensors and their output circuits, circuit phase-by-phase regulation of the switching devices and the control circuit "ABOVE", "BELOW", characterized in that the outputs of the position sensors connected to the inputs of the element I1, the output of the element I1 is connected to one of the inputs of the element I2, the control circuit "ABOVE", "BELOW" is connected to the second input of the element I2, the output of element I2 is connected to the input element and the control circuits of the switching devices in the mode "SIMULTANEOUSLY", and the output element is NOT connected to the control circuits of the switching devices in the "PHASES".
FIELD: electric engineering.
SUBSTANCE: output pulse-width signal for controlling adjusting member of converter is got as a result of conjunction of two pulse-width signals. First signal is formed on the base of voltage error signal, the second signal - on the base of current error signal. Level of current error signal is subject to correction depending on value of demodulated output pulse-width signal for controlling adjusting member. In case the output signal reaches preset limit value and converter switches from voltage stabilization mode to current stabilization mode, the error of stabilization of converter output current can be reduced.
EFFECT: reduced error of current stabilization.
FIELD: electrical engineering; ac-to-dc voltage converters affording load protection against surges occurring in ac voltage supplies.
SUBSTANCE: proposed secondary power supply has diode rectifier bridge 4 with LC ripple filter 5 connected to its outputs, and load 6. First input of diode rectifier bridge 4 is connected to output of first regulation unit 2 whose input is connected to one of poles of ac voltage supply 1. Newly introduced is second regulation unit 3 whose input is connected to other pole of ac voltage supply 1 and output, to second input of diode rectifier bridge 4. First and second regulation units 2 and 3 incorporate group of N series-connected transistor switches 8.1 through 8N, control resistors 7.1 through 7.N, voltage regulator diodes 9, 14, 18, 21, capacitors 10, 17, resistors 11, 12, closing and opening MIS transistors 13 and 15, respectively, and diodes 19, 20.
EFFECT: enhanced speed of response of protective gear.
2 cl, 1 dwg
FIELD: electrical engineering, applicable for compensation of the excessive reactive power of the power line and for the change of the total lever of voltage in it within a wide range.
SUBSTANCE: the device has a magnetic core with yokes and the main rod divided into two longitudinal parts: a rod without air gaps with the control winding and the successive section of the network winding enveloping it positioned around it, and a rod with air gaps. The compensation winding and the general part of the network winding envelop the rod without air gaps with the mentioned windings and the rod with air gaps.
EFFECT: combined functions of control of the reactive power in the reactor-autotransformer and control of the voltage in the power lines within a wide range.
5 cl, 4 dwg
FIELD: electric and radio engineering, possible use as low power support voltage sources in various functional units of analog interfaces.
SUBSTANCE: controllable supply of supporting voltage (dwg. 3) contains output transistor (1), emitter of which is connected to first output unit (2) of controllable supply of supporting voltage and to current-stabilizing dipole (3), connected to bus of power supply (4), and collector is connected to second (5) output unit of controllable source of supporting voltage, auxiliary voltage repeater (6), output of which is connected to first contact of auxiliary resistor (7). Base of output transistor (1) is connected to second contact of auxiliary resistor (7) and to additional controlling source of supporting current (8), and input of auxiliary voltage repeater (6) is connected to collector of output transistor (1).
EFFECT: creation of controlled analog of stabilitron - dipole with electronically changeable level of stabilization voltage.
3 cl, 12 dwg
FIELD: reactive power correction and total voltage level regulation in power transmission line.
SUBSTANCE: proposed device has magnetic circuit with main leg that carries main winding incorporating series- and parallel-wound parts with center tap, compensating winding, and control winding closed to thyristor-controlled unit. Series-wound part of winding has two differentially connected coils, one of them being enclosed by control winding. Higher-harmonic filter is connected to compensating winding.
EFFECT: enlarged functional capabilities.
3 cl, 3 dwg