SU1241137A1 - Transducer of active power - Google Patents

Abstract

The invention relates to electrical measuring technology and can be used in the construction of high-growth, cheap, reliable, power sensors. The purpose of the invention is to increase the reliability of the converter. For this, a threshold unit is inserted into the device containing the phase-sensitive expander. The phase-sensitive rectifier is made up of resistors 2-7, Zener diode 10, transistor 11, collector circuit of transistor 12. Resistor 1, diode 8, Zener diode 9, the base circuit of transistor 12 form a threshold unit, which voltage is approximately equal to the stabilization voltage of the Zener diode 9. The absence of winding products and capacitors makes it possible to integrate it. 3 il. (L Bxodi 075 1 0 (rig, 7

Description

The invention relates to electrical measuring technology and can be used in the construction of simple, cheap and reliable power sensors.

The purpose of the invention is to increase the reliability of the converter.

FIG. 1 is a schematic diagram of the proposed converter; in fig. 2 -. timelines for clarification; his work in FIG. 3 - dependence of the methodological error of the conversion on the ratio; threshold on the voltage of the circuit under study.

The converter includes resistors 1-7, diode 8, zener diodes 9 and 10, and transistors 11 and 12.

The input bus 13 voltage through a series-connected diode. 8, the resistor 1 and the zener diode 9 are connected to the base of the transistor 12, the emitter of which is connected to the common bus 14 and through the resistor 4 to the input current bus 15 and the first pin of the resistor 3, the second cable of which through the resistor 2 is connected to the power bus 16, and the engine through the resistor 5 is connected to the base of the transistor 11, the collector of which is connected to the first output bus 17 and through the resistor 6c to the power supply bus 16, and the emitter to the collector of the transistor 12 and the anode of the Zener diode 10, the cathode of which is connected to the second output bus 18 and through the resistor 7 to the bus 16 food.

Resistor 1, diode 8, zener diode 9 and the base circuit of transistor 12 form a threshold block, the voltage of which is approximately equal to the stabilization voltage of the stabilizer 1ltron 9. Resistors 2-7, Zener diode 10, transistor 11 and the collector

with attitude. The moments of opening and closing of the transistor 12 os li - oi are determined from the pressure

to

15

25

About

arcsin

where - amplitude sinusoidal

voltage Ug.

When the transistor 12 is energized, the power is supplied from a constant voltage source U via the bus 16 pitsa to the current signal amplifier, which is connected to the transistor 11, the base of which receives current from a predetermined bias voltage, indicated by the drift of resistor 3, and the voltage of the current signal B, which is higher on the low-resistance resistor 4, is passing through the load

20 current (direct or transformed). Since the transistor 11 is operating in class A mode, the potential of the collector of the transistor 11 varies throughout the open state transient of transistor 12 in accordance with the load current. If, in this case, the bias voltage is matched by the reference voltage of the Zener diode, then between the spin buses 17 and 18

30 there will be a voltage U versus the input current signal UjQ and proportional to it in a certain range of values of the load TOKai.

35 In the negative half-wave of the applied voltage, the transistor 12 is closed and the voltage U is zero (Fig. 2).

Mean Stress Up

40, the period is determined by the open state of the transistor. 1 amplitude dependent load

the tanzistor 12 circuit forms a phase-sensitive voltage,.

with attitude. The moments of the opening and closing of the transistor 12 wasp and li - oi are determined from the voltage

About

arcsin

where is the amplitude of the sinusoidal

voltage Ug.

When the transistor 12 is pressed, power is supplied from the DC voltage source U via the power bus 16 to the current signal amplifier assembled on the transistor 11, the base of which receives the current from a predetermined bias voltage determined by the drift position of the resistor 3 and the voltage. current signal B, which is assigned to the low-resistance resistor 4 when the load current passes through it

current (direct or transformed). Since transistor 11 operates in class A mode, the collector potential of transistor 11 varies throughout the open state of transistor 12 in accordance with the load current. If you agree on the bias voltage with. the reference voltage of the Zener diode 10, then between the second tires 17 and 18

there will be a voltage U inverse to the input current signal UjQ and proportional to it in a certain range of values of the load TOKai.

In the negative half-wave of the load voltage, the transistor 12 is closed and the voltage U is zero (Fig. 2).

Mean Stress Up

over a period, the duration of the open state of the transistor is determined. 12, depending on the amplitude of the load-carrying superior.

The active power converter operates as follows.

The voltage Ug, on the bus 13, which is the signal of the load voltage, reaches the base current and the end of the transistor in its positive half-period. 12 when exceeding the cut-off voltage of the protravny sum of the stabilization voltage of the Zener diode 9 and the direct voltage of the base-suedertransistor of the transistor 12. At the same time, the open-state duration of the transistor 12 is determined by the time for WHAT OM Ugj zana

load current and phase between current and voltage. Thus, there is the effect of a controlled phase straightening of the signal, depending on the product of the load current, voltage and function of the angle between

For sinusoidal load current and voltage, the average for the period, the value of Up.p is determined by the expulsion

Yy l

 Fo

.l (

about

de

to Cr -.

3

 to,

Fo

fO

t5

the coefficient determined by the amplification factor K of the current amplifier, the conversion factor K; load current to voltage and dd, conversion factor KU Load g6 voltage to voltage Ugoj, jj P UI cos cf - load power is active. ki;

and - amplitude

controlled load voltage.

Expression analysis for U. shows then. at constant values of the coefficients K, K |, Cc; what is possible for a wide range of load currents ° voltages, the value of U. reflects the ktivnuyu power of the circuit with a methodological error determined by the expression

35

1241

five

Uro KU U

one-(

Nm

KuUr.

-)

four

value of value

KOTopoi o from

relationship

 - submitted to

and

Fo

FIG. 3. For less error

t t ef - J (YV (

than 4%, the range of value ---

and FJ,

is in the range of 1.25-1.7, which, at a nominal value of 1.55, makes it possible to reflect with high enough accuracy the value of the active power in the load when the load voltage varies in the range from 80 to 110% of the nominal value. At the same time, there are no restrictions on the value of the phase, current frequency and voltage.

The proposed Converter easier known and, therefore, more reliable. The absence of winding products and capacitors provides the possibility of its integral performance,

Claims (1)

Invention Formula An active power transducer containing a phase-sensitive rectifier whose input is connected to an input current bus, which is different from the fact that, in order to increase reliability, a threshold unit is inserted into it, the input of which is connected to the input voltage bus, and the output - to the control input of the phase-sensitive rectifier, the output of which is upstream of the converter. TO : - " fi z %