SU881962A1 - Method of stabilizing thyristorized regulator output power - Google Patents

Description

The invention relates to electrical engineering and can be used to stabilize the output power of a thyristor regulator operating at a resistive load. In modern power stabilization devices, power stabilization methods are used, based on current and voltage measurement and then multiplied. Known power transducers on varistors with a quadratic volt-ampere characteristic 1, Transmitters transducers known to be built on diodes 2 are known. The principle of operation of such transducers is built on two elements with a quadratic volt-ampere characteristic (square, ra). The disadvantage of these methods is their operational complexity, namely; it is necessary to measure two parameters — the current and voltage of the controlled circuit, to receive signals proportional to the sum of and –K; 1 and the spacing: and - K i i, to multiply (U + К-, i) х (U-Kii). The time-pulsed method of measuring power 3 is known. It provides for pulse-width modulation with an output pulse duration or a relative difference in pulse widths of different polarity linearly or non-linearly associated with. voltage (current) of the controlled circuit. And then this signal is subjected to amplitude modulation depending on the current (voltage) of the controlled circuit. Thus, a twice-modulated Vudet signal is proportional to the product of the voltage per current of the monitored circuit. The disadvantage of this method, as well as all known ones, is the complexity of their application in practice, since it is necessary to measure two signals — voltage and current — and multiply them. Closest to the present invention is a method for stabilizing the output power of a thyristor regulator operating on a resistive load, according to which the measured average value of the current and the duration of the current pulses transmitted by the thyristor regulator 3. However, this method is complicated. The purpose of the invention is to simplify the method. This goal is achieved in that, according to the limestone method, to obtain a negative feedback signal, a signal proportional to the average current value of the thyristor controller is generated, which is modulated by the measured value of the current pulse duration. Consider the basic theoretical assumptions that make it possible to implement the proposed method. For definiteness, we assume that the alternating current power circuit is single phase. On average, the output power of a thyristor controller operating on an active load is equal to

:, p um. (I.COS),

About 1 II Hip

 to -Usr (1 -vcoso).

From (1) it follows that the average value of the power is proportional to the product of the average value of the current of the thyristor controller (or load) and the function of the angle c,

f (c) - (lttos t).

C2)

The angle ot is unambiguously related to the duration of the current pulse L — oC. Therefore, it can be argued that whatever the voltage at the output of the thyristor regulator operating on the resistive load, it will unambiguously characterize the duration of the current pulse.

The product of the average value of the load current by the angle I- or H) (K cos.) Can be obtained if the average voltage of the current sensor and the data. . apply to the pulse-width modulator, for which the duration of the output pulse is 1 c.) C-o1 or

tu. (-t-cosct).

In the first case, the voltage at the output of the pulse-pulsed -modulator is non-linearly related to power, in the second - linearly. Any dependency can be applied to stabilize the power.

FIG. 1 shows a block diagram with which ocjratecTBHTb power stabilization can be used; in fig. 2 - stress diagrams.

 The flowchart contains a thyristor 1 controller, a current sensor 2, an input device 3, an integrating device 4, a pulse-width modulator (PWM) 5, a control unit 6.

 (Gi)

),

Wed Shim T

where is H and J

In this way, a time-pulse power measurement is implemented using a current sensor, which is a source of average current and time signals JL - оС

If the average voltage of the current sensor is id. Wed K3j, p apply to the pulmonary pulse (Ny modulator, whose output pulse duration is tu- (1 + cosot), then the average voltage at the PWM output is linearly related to

MOUNTAIN

., ml ..- m, 1

to sr-ss

RT

The use of the proposed method for stabilizing the power of a thyristor controller has an advantage over existing methods, namely the use of a signal,. proportional to the current taken from the current sensor (e.g., current transformer) to control the pulse-width modulator, eliminates the need for measuring the voltage across the load and greatly simplifies the power meter.

Claims (3)

1. Fremke A.V., et al. Statistical transducer of active power using short-circuit semiconductor resistances. Lime universities Instrumentation, 5 1965, N «1. 2. Karandeev K. B. and others. On multiplying circuits on semiconductor diodes, Measuring equipment, 1964, N 11. 3. Benin V. L. and others. Statistical measuring transducers of electric power. M., Energie, 1972, p. 14 (prototype). and. t Uhh Ui gtsr. 6, y but  "I ak J (/. Ull / H y ////. W / 7 /. At //// L ///// %% Y7