SU1684858A1 - Device for controlling reactive power - Google Patents

Abstract

The invention relates to a converter technique and can be used in the construction of regulated sources of reactive power for transverse and longitudinal compensation. The purpose of the invention is to reduce the distortion of the generated current and increase efficiency by introducing two current inverters 11, 12 connected via pulse shapers 13 and 14 respectively with a common master oscillator 15, the output of each of the inverters is connected in parallel to the corresponding winding of the outermost rods 9, 10 of the magnetic circuit 5, and pulse generator 14 is connected to the master oscillator through a phase shifter 16, the control input of which is connected to the output of the measuring transducer 4. The change in the magnetic resistance of the middle core of the magnetic circuit 5, and accordingly the inductance of the winding 6, due to the magnetic flux of the mutual induction caused by the change in the output signal of the measuring transducer 4 , allows to regulate the reactive power delivered to the network 8 depending on its deficit 1 sludge C

Description

about

00

soo oo

The invention relates to the field of converter technology and may find application in the construction of regulated sources of reactive power for transverse and longitudinal compensation.

The aim of the invention is to reduce the distortion of the shape of the generated current and increase efficiency.

The drawing shows a functional diagram of the device.

The device for automatic control of reactive power comprises a network mode sensor 1 comprising current transformers 2, voltage 3, measuring transducer 4 and a source of reactive power. The reactive power source contains a three-core magnetic conductor 5, the winding of the middle rod b of which is connected via a capacitor 7 to the distribution network 8. The windings 9 and 10 with the like terminals connected together are connected according to and located on the extreme rods of the magnetic conductor 5, each of them is connected in parallel to the output of the corresponding inverters 11 and 12 current. Each of the inverters 11,12 current has its own pulse shaper, respectively 13 and 14. The shaper 13 and 14 pulses are connected to a common master oscillator 15, providing a current frequency of inverters 11, 12, equal to the frequency of the supply voltage 8 The oscillator 15 is connected to the driver 14 pulses through a controlled phase shifter 16. The control input of the phase shifter 16 is connected to the output of the measuring transducer 4.

A device for adjusting reactive power works as follows

When a reactive power source is connected to the supply network 8, in which there is a reactive power deficit, the equivalent resistance of the series circuit of the capacitor 7 and the inductance of the transformer winding 6 has a capacitive character due to a mode close to the voltage resonance. At the same time, the source generates the maximum reactive power to the network 8 at small values of the installed capacity of the capacitor 7 and the magnetic transformer transformer 5. If the reactive power of the source does not cover the deficit of the reactive power of the network 8, then there is no signal from the sensor 1 of the network mode and the driving pulses from the generator 15 arrive at shapers 13 and 14 in phase. The magnetic fluxes in the extreme rods of the magnetic circuit 5, caused by the flow of currents of inverters 11 and 12 through the windings 9 and 10, are closed in the middle core of the magnetic circuit 5 in antiphase, due to the consistent switching on of the windings 9 and 10 without causing a change in the circuit of the windings 6 and the operation mode of the circuit capacitor 7 - winding 6.

When the capacitive reactive power of the device is exceeded, the reactive power of the network 8 from the sensor 1 mode

the network to the control input of the phase shifter 16 receives a control signal proportional to the difference in reactive power. Depending on the magnitude of the control signal, a phase shift of the pulses is created,

incoming from the generator 15 to the shaper 14 pulses for the inverter 12. As a result, there will be a phase shift between the magnetic fluxes of mutual induction from the windings 9 and 10 in the middle rod

magnetic 5, different from 180 e. i rad The resulting magnetic flux of mutual induction in the middle rod will cause a change (decrease) in the inductive resistance of the winding 6, and accordingly

and the mode of operation of the circuit capacitor 7 - winding 6 with a subsequent decrease in the value of reactive power to ensure full compensation in the distribution circuit 8. Power supply for the inverters 11 and 12 current

is carried out in the usual way from direct current sources, which are conventionally not shown in the drawing.

The change in the magnetic resistance of the middle core of the magnetic circuit 5, and accordingly the inductance of the winding 6 due to the magnetic flux of mutual induction caused by the phase mismatch of the current inverters 11 and 12, is carried out without distorting the controlled current in the power circuit. The range of control of the reactive power of the device is nr-, this is 90%.

Claims (1)

Claims An apparatus for adjusting reactive power, comprising a current transformer, a voltage transformer, a source of reactive power, made in the form of a capacitor connected by a first lead to a terminal for connecting to the network, and the second lead to a three-core magnetic circuit containing windings on each rod, a phase shifter and a pulse generator connected by a first output to an input of a pulse former, characterized in that, in order to reduce the distortion of the shape of the generated current and increase the efficiency , the second impulse generator, two current inverters and measurements were additionally introduced5 16848586 A separate converter connected to the input of the second inverter is connected to the outputs of the current transformer, the windings of the extreme rods and the voltage transformer, and the output of the magnetic conductor are connected according to and under the first input of the phase shifter, the second is connected to the outputs of the current inverters, one input of which is connected to the second output-5 the nominal ends of the windings are connected between the generator and the output of the phase shifter, and the winding of the middle magnesium rod is connected through a second transducer through a capacitor connected It is connected to the pulses to the input voltage of the first inverter to the terminal for connection to the distributor, the output of the first generator of the pulse network.