RU2470360C1 - Multipoint integrating ac voltage controller with automatic control channel backup - Google Patents

Abstract

FIELD: physics; control.

SUBSTANCE: invention relates to controllers. Disclosed is a controller, having series-connected control signal source - input terminal, a first adder, an integrator whose output is connected to the input of the first, second and third relay elements, whose outputs are connected to inputs of the first, second and third comparators, respectively; the output of the first, second and third comparators is connected to the D input of a first, second and third dynamic D flip-flops, respectively, phase A, B and C buses connected to the corresponding inputs of a three-phase load with a neutral terminal through the first, second and third power switches, respectively, whose control inputs are respectively connected to the output of the first, second and third dynamic D flip-flop; the controller also has a second adder whose output is connected to the second input of the first adder; fourth, fifth and sixth comparators whose inputs are connected to phase A, B and C buses, respectively; the outputs of the fourth, fifth and sixth comparator are connected to the C input of the first, second and third dynamic D flip-flop, respectively; wherein the controller also has seventh, eighth and ninth comparators, whose outputs are connected to corresponding inputs of the second adder, and the inputs of the seventh, eighth and ninth comparators are connected to outputs of the first, second and third dynamic D flip-flops, respectively.

EFFECT: possibility of self-backup and high reliability of the controller.

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Description

The invention relates to power conversion technology and can be used in temperature controllers with automatic redundancy of control channels.

A known control system with automatic redundancy (SU No. 1294152, G05B 9/03, H05K 10/100, application. 02.08.85, publ. 07.02.87, bul. No. 5), containing integrating deploying converters, diagnostic units, feedback sensors , key switch, actuator. The disadvantage of this device is its lack of reliability due to the lack of diagnostic tools for key switches.

Known multi-zone integrating deploying converter (MCI) (SU No. 1283801, G06G 7/12, application. 05.22.85, publ. 15.01.87, bulletin No. 2), containing adders, a group of parallel integrators, an odd number of relay elements.

The device is characterized by high reliability in case of single failures of relay elements and belongs to the class of systems with self-diagnosis of active components of the circuit and automatic commissioning of workable elements (Tsytovich L.I. Multi-zone deploying converter with an adaptable structure in the function of the fault function // Devices and Technique experiment. - M.: Academy of Sciences of the USSR, 1988. - No. 1. - C81-85).

A disadvantage of the known technical solution is the impossibility of its operation at zero output failures of relay elements, which may be associated, for example, with an emergency shutdown of the power source. Thus, the device is not sufficiently reliable in the event of a power failure.

Known MCI (SU No. 1183988, IPC G06G 7/12, application form 27.04.84, publ. 07.10.85, bulletin No. 37) containing adders, integrator, relay elements, input and output terminals.

The device belongs to the class of self-oscillating frequency-latitude-pulse (CWPM) converters of the integrating type, has high noise immunity and accuracy, due to the closed nature of the MCI structure and the presence of an integrator in the direct control channel.

However, the known technical solution has limited functionality and low redundancy when used to control power converters.

Closest to the proposed device is a multi-zone AC voltage regulator (PH) (patent SU No. 2408969, IPC Н02М 5/293, application form 23.12.09, publ. 10.01.11, bulletin No. 1), containing a series-connected source of the reference signal the first adder, the output of which is connected to the inputs of three relay elements, the outputs of which are connected to the inputs of the second adder, the output of which is connected to the second input of the first adder, three comparators, the inputs of which are connected to the output of the corresponding relay elements, three key elements, each of which is connected between the source of the corresponding phase of the three-phase voltage source and the load connected according to the star circuit with a zero output, the output of the second and third comparators are connected to the control input of the second and third key elements, respectively, the fourth comparator and the dynamic D-trigger, and the input of the fourth comparator connected to the power input of the first key element, and the output is connected to the C-input of the D-trigger, the D-input of the D-trigger is connected to the output of the first comparator, and the output of the D-trigger is connected to the control vlyayuschemu input of the first key member.

The disadvantage of the prototype device is its low reliability in case of failure of the relay elements of the MCI. So, when the first relay element fails, the dynamic D-trigger connected to its output through the comparator is in a static position, and the frequency-pulse-width-modulation mode in the LV breaks down. As a result, the system partially or completely loses its functionality. Its partial preservation is possible only in the presence of a feedback loop, when the LV can transition from self-oscillation mode to relay control mode. However, this reduces the accuracy and range of regulation.

The invention is based on a technical problem, which consists in providing the possibility of self-reservation (automatic backup) and increasing the reliability of the claimed device in case of failures of its active components.

The indicated technical problem is solved in that a multi-zone integrating AC voltage regulator with automatic redundancy of control channels, containing a control signal source in series - an input terminal, a first adder, an integrator whose output is connected to the input of the first, second and third relay elements, the outputs of which are connected to the inputs of the first, second and third comparators, respectively, the output of the first, second and third comparators is connected to the D-input of the first, second and third dynamic D-flip-flops, respectively, phase A, B, C buses connected to the corresponding inputs of the three-phase load with zero output through the first, second and third power switches, respectively, whose control inputs are connected to the output of the first, second and third dynamic D-flip-flops, respectively , also containing a second adder, the output of which is connected to the second input of the first adder, the fourth, fifth and sixth comparators, the inputs of which are connected to the phase buses A, B, C, respectively, the output of the fourth, fifth and sixth the parator is connected to the C-input of the first, second and third dynamic D-flip-flops, respectively, and is characterized by the fact that the seventh, eighth and ninth comparators are introduced into it, the outputs of which are connected to the corresponding inputs of the second adder, and the input of the seventh, eighth and ninth comparator is connected to the outputs of the first, second and third dynamic D-flip-flop, respectively.

The technical result of the proposed device is its automatic self-reservation capabilities and, as a result, the increased reliability of the device, achieved due to the fact that in case of failure of any element included in its closed loop, the system is restored by automatically entering one of the parallel oscillations regulation channels.

A distinctive feature of the claimed solution is that the seventh, eighth and ninth comparators are introduced into the voltage regulator, the outputs of which are connected to the corresponding inputs of the second adder, and the inputs of the seventh, eighth and ninth comparators are connected to the outputs of the first, second and third dynamic D-flip-flops, respectively. As a result, all elements of the device turn out to be covered by general feedback, with the help of which the system automatically searches for a working regulation channel and turns it on.

The invention is illustrated by drawings, where:

figure 1 - is a functional diagram of the proposed device;

figure 2 - shows the characteristics of the main elements of the proposed device;

figure 3 - shows the structure of MCI;

4 is a timing diagram of the signals of the MCI;

5, 6 are timing diagrams of the signals of the proposed device;

7, 8 - shows the timing diagrams of the signals of the proposed device when it is simulated in the package "Matlab + Simulink".

The structure of the device (Fig. 1) includes a serially connected control signal source 1, a first adder 2, an integrator 3, the output of which is connected to the input of the first 4, second 5, and third 6 relay elements. The outputs of the relay elements 4, 5 and 6 are connected to the inputs of the first 7, second 8 and third 9 of the comparator, respectively. The outputs of the comparators 7, 8 and 9 are connected to the D-inputs of the first 10, second 11 and third 12 dynamic D-flip-flops, respectively. C-inputs of D-flip-flops 10, 11 and 12 are connected to the outputs of the fourth 13, fifth 14 and sixth 15 of the comparator, respectively. The inputs of the comparators 13, 14 and 15 are connected to the phase buses A, B, C, respectively. The outputs of the D-flip-flops 10, 11 and 12 are respectively connected to the inputs of the seventh 16, eighth 17 and ninth 18 of the comparator, and are also connected to the control inputs of the power switches 19, 20 and 21, respectively. The outputs of the seventh 16, eighth 17 and ninth 18 comparators are connected to the corresponding inputs of the second adder 22, the output of which is connected to the second input of the first adder 2. Phase bus A, B, C - terminals 23, 24 and 25 are connected respectively through the first 19, second 20 and the third 21 power switch to the corresponding inputs of the three-phase load with zero output 26 - terminals 27, 28, 29, respectively.

Elements of a multi-zone integrating AC voltage regulator with automatic redundancy of control channels have the following characteristics.

Adders 2 and 22 are made with equal transmission coefficients for each of the inputs. In the future, we believe that these transmission coefficients are equal to 1.0.

Integrator 3 is implemented with a transfer function of the form W (p) = 1 / T _and p, where T _and is the time constant. Its output signal increases linearly with a jump in the input action with a sign opposite to the sign of the input signal (figa).

Relay elements 4, 5, 6 have a symmetrical hysteresis loop and switching thresholds that satisfy the condition

| ± b ₁ | <| ± b ₂ | <| ± b ₃ |,

where ± b _i are the switching thresholds of the corresponding relay elements 4, 5, 6. The output signal of each of the relay elements 4, 5, 6 varies discretely within ± A / 3 (Fig.2b).

The comparators of the first group 7, 8 9 have a non-inverting characteristic with zero switching thresholds, are designed to convert a bipolar input signal into unipolar pulses (pigv) and perform the functions of repeaters with a truth table

entrance Exit A / n one -A / n 0

where ± A is the maximum value of the output signal of the adder 22 MCI.

The comparators of the second group 13, 14, 15 have a characteristic similar to the first group of comparators 7, 8, 9 and switch to the state “1” with a positive half-wave of the phase voltage (Fig.2d).

The comparators of the third group 16, 17, 18 are hysteresis-free with a switching threshold of “+ C” (Fig. 2d) and are designed to convert unipolar pulses to bipolar pulses.

D-flip-flops 10, 11, 12 are dynamic and switch on the leading edge of the pulse at the C-input to a state that has a D-input (Fig. 2e).

Power switches 19, 20, 21 go into a closed position with a signal "1" at their control input.

Load 26 is hereinafter considered active.

In the diagrams of the MCI signals (FIG. 3, FIG. 4), the following notation is adopted:

X _I - input signal (input terminal 1);

Y _and (t) is the output signal of the integrator 3;

Y _Pl , Y _P2 (t), Y _P3 (t) - output signals of relay elements 4, 5, 6, respectively;

Y _o (t) is the output signal of the adder 22;

Y _c - the average value of the output pulses of the adder 22.

The principle of operation of a multi-zone integrating AC voltage regulator with automatic redundancy of control channels is as follows.

If we assume that the outputs of the relay elements 4, 5 and 6 are connected directly to the adder 22, and the comparators of the first group 7, 8, 9 are disconnected from the outputs of the relay elements 4, 5, 6. We also assume that the outputs of the comparators of the third group 16, 17, 18 are disconnected from the second adder 22, the inputs of which are connected to the outputs of the relay elements 4, 5, 6. In this case, the classical MCI structure is obtained (Fig. 3), which works as follows.

When turning on the MCI and the zero input signal X _BX (input terminal 1), the relay elements 4, 5 and 6 are set arbitrarily, for example, in the state + A / 3 (figv-d). Under the action of the scan signal Y _and (t) from the output of the integrator 3 (Fig.4b), the two relay elements 4 and 5 are sequentially switched to the position -A / 3 (since the relay elements 4 and 5 have the lowest switching thresholds b ₁ and b _2, respectively) (Fig. 4c, d, time instants t ₀₁ , t ₀₂ ), after which the direction of the sweep transform changes, and the signal Y _and (t) at the output of the integrator 3 rises in the positive direction.

Starting from the moment the condition Y _and (t) = b _{1 are} fulfilled, the MCI enters the stable self-oscillation mode when the amplitude of the Y _and (t) sweep signal is limited by the ambiguity zone of the first relay element 4 (with minimum switching thresholds b ₁ ) and the second 5 and the third 6 relay elements are in static and opposite in sign sign of the output signals Y _P2 (t), Y _P3 (t) states (Fig.4g, d). The coordinate Y _o (t) at the output of the adder 22 is formed by switching the first relay 4 (Fig.4c) in the first modulation zone, limited by ± A / 3 (Fig.4e).

) влечет за собой изменение частоты и скважности импульсов Y_вых(t), так как в интервале t₁ (фиг.4в) развертка Y_и(t) (фиг.4б) изменяется под действием разности сигналов, подаваемых на сумматор 2 (фиг.4а, е), а в интервале t₂ - dY_и(t)/dt зависит от суммы этих воздействий. В результате Y₀≡Х_вх (фиг.4е).In the absence of X _I (Fig. 4a, t <t ₀ ), the average value Y _{0 of the} pulses Y _o (t) is zero. The presence of the input coordinate X _I <(A / 3) (figa,

) entails a change in the frequency and duty cycle of the pulses Y _o (t), since in the interval t ₁ (Fig. 4c) the scan Y _and (t) (Fig. 4b) changes under the influence of the difference of the signals supplied to the adder 2 (Fig. 4a, e), and in the interval t ₂ - dY _and (t) / dt depends on the sum of these effects. As a result, Y ₀ ≡X _in (Fig. 4e).

сигнал Х_вх увеличился дискретно до величины (А/3)<Х_вх<А (фиг.4а). Это нарушает условия существования режима автоколебаний в первой модуляционной зоне, и МРП переходит на этап переориентации состояний второго и третьего релейных элементов 5 и 6, который заканчивается в момент времени t₀₃, когда релейный элемент 6 переключается в положение -А/3 (фиг.4д). Координата Y_вых(t) достигает уровня - А (фиг.4е), и МРП переходит во вторую модуляционную зону, где в интервалах t₁, t₂ (фиг.4в) скорость формирования развертывающей функции Y_и(t) (фиг.4б) также определяется разностью или суммой сигналов, воздействующих на сумматор 2. При этом сигнал Y₀ включает постоянную составляющую -А/3 первой и среднее значение импульсного потока Y_вых(t) второй модуляционной зоны (фиг.4е). Переход МРП из одной модуляционной зоны в другую для малых приращений координаты Х_вх сопровождается переходом системы через характерные точки с нулевым значением частоты несущих колебаний (режим частотно-нулевого сопряжения модуляционных зон).If at time

the signal X _I increased discretely to a value of (A / 3) <X _I <A (figa). This violates the conditions for the existence of a self-oscillation mode in the first modulation zone, and the MCI goes to the stage of reorientation of the states of the second and third relay elements 5 and 6, which ends at time t ₀₃ , when the relay element 6 switches to the position -A / 3 (Fig.4d ) The coordinate Y _o (t) reaches level A (Fig. 4e), and the MCI goes into the second modulation zone, where in the intervals t ₁ , t ₂ (Fig. 4c) the formation speed of the developing function Y _and (t) (Fig. 4b) ) is also determined by the difference or the sum of the signals acting on the adder 2. In this case, the signal Y ₀ includes the constant component -A / 3 of the first and the average value of the pulse flow Y _o (t) of the second modulation zone (Fig. 4e). The transition of the MCI from one modulation zone to another for small increments of the X _I coordinate is accompanied by a transition of the system through characteristic points with a zero value of the frequency of the carrier oscillations (frequency-zero conjugation of the modulation zones).

The MCI in each modulation zone is a system with pulse-width-pulse-width modulation, when with increasing X _{in the} frequency of the output pulses decreases and at the interface between the modulation zones it becomes zero. Moreover, in the entire range of changes in the input action X _{I, the} amplitude characteristic Y ₀ = f (X _BX ) of the MCI is linear, which is explained by the closed nature of the structure of the MCI and the presence of an integrator 3 in the direct control channel.

The difference between the proposed multi-zone integrating AC voltage regulator with automatic redundancy of the control channels (Fig. 1) from the classic MCI circuit (Fig. 3) is that the comparators 7, 8, 9, 13, 14, 15 and D-triggers 10, 11 , 12 due to the introduction of the comparators 16, 17, 18 and the connection of the adder 22 to the outputs of the comparators 16, 17, 18 are "inside" the closed loop control MCI, which improves the reliability of the proposed device in case of failure of a larger number of components than allowed by the circuit figure 3.

Consider the work of a multi-zone integrating AC voltage regulator with automatic redundancy of control channels as a whole. We believe that X _BX = 0. We also believe that the switching of blocks 4, 7, 10, 16 occurs synchronously with the moment of fulfillment of the condition | Y _AND (t) | = | b ₁ |.

Under such conditions, the first relay element 4 with the minimum value of switching thresholds (Fig. 5c) will be in the self-oscillation mode, and the state of the relay elements 5 and 6 depending on the initial orientation is, for example, + A / 3 and - A / 3, respectively (fig.5e, e).

The comparators of the first group 7, 8, 9 convert the bipolar input signal (Fig.5c) into unipolar pulses (Fig.5g), which set the desired state of the dynamic D-flip-flops 10, 11, 12.

The comparators of the second group 13, 14, 15 switch to the state "1" during the formation of a positive half-wave phase voltage (figa, b).

Dynamic D-flip-flops 10, 11, 12 switch on the leading edge of the pulses from the outputs of the comparators of the second group 13, 14, 15 to the state that their D-input has. As a result, the power switch 19 is operating in the frequency-pulse-width-modulation mode (FIG. 5g), the power switch 20 is constantly on (FIG. 5z), and the power switch 21 is in the “hot” standby state (FIG. 5i).

In particular, the comparator of the second group 13 generates pulses "1" synchronously with the "positive" half-wave voltage of phase A (figa, b). The first relay element 4 sets the necessary state of the comparator of the first group 7 and the first D-flip-flop 10, to which it switches by the first pulse that matches the signal "1" at the output of the comparator of the first group 7 (fig.5b, d, g). Turning off the D-trigger 10 occurs on the first pulse within the "zero" state of the comparator 7 (fig.5b, d, g). As a result, in the interval t ₀₁ -t ₀₂ (Fig. 5g), a “zero” pause is formed in the phase A load.

,

(фиг.5в) и период Т₀=t₁+t₂=2Т, где «Т» - в общем случае параметр схемы ШИМ или ЧШИМ, имеющий размерность времени;

- нормированная величина входного сигнала. В случае ЧШИМ

,

,

. Тогда диапазон регулирования

для силовых ключей 19, 20, 21 при ШИМ заведомо имеет конечную величину, ограниченную входным сигналом

, так как диапазон «D» не может быть равным нулю, а для ЧШИМ

практически неограничен.The use of the PWM mode allows you to significantly improve the energy performance of the proposed controller and for power switches 19, 20, 21 to get an unlimited range of regulation. Indeed, with pulse width modulation (PWM)

,

(Fig. 5c) and the period T ₀ = t ₁ + t ₂ = 2T, where “T” is, in the general case, a PWM or PWM scheme parameter having a time dimension;

- normalized value of the input signal. In case of WSSM

,

,

. Then the regulation range

for power switches 19, 20, 21 with PWM, it obviously has a finite value limited by the input signal

, since the range “D” cannot be equal to zero, but for WSSM

almost unlimited.

Consider the operation of the proposed device in case of failure of the first relay element 4 (Fig.6), when it goes into an uncontrollable state + A / 3 (Fig.6c). In this case, the first dynamic D-flip-flop 10 is in the static state “1”, and the power switch 19 (phase A) is closed (FIG. 6g).

Then the self-oscillation mode occurs in the path of the second relay element 5 having switching thresholds ± b ₂ (Fig.6g), and the power switch 20 (phase B) (Fig. 6z) goes into the on / off state. Power switch 21 (phase C) retains its static "zero" position (Fig.6i).

In a real system, the output signal of the integrator 3 (Fig.6d) may exceed the threshold level of the relay element in the mode of self-oscillations (in this case ± b ₂ ) by | Δb ₂₁ | ≠ | Δb ₂₂ |, which is caused by the delay introduced by the corresponding from dynamic D-flip-flops 10, 11, 12. However, this delay corresponds to one period of the mains voltage and may not be taken into account at the frequency of self-oscillations of the MCI, calculated in parts or units of hertz.

The further behavior of the multi-zone integrating AC voltage regulator with automatic redundancy of the control channels in case of failure of its elements depends on the nature of these failures. For example, if there occurs a “zero” failure of the second relay element 5 (uncontrolled state - A / 3), then the self-oscillation mode will remain in the path of the third relay element 6, and the system will maintain its operability. With a “single” failure of the second relay element 5 (state + A / 3), the system will be malfunctioning.

A similar situation will be with failures of other elements of the proposed device. For example, not one relay element 4, but one of the blocks 7, 10, 16 may go into a faulty “zero” or “single” state. Their failures are equivalent to the failures of the relay element 4, since they, in essence, together with the first relay element 4 cases are the sequential inclusion of key elements, and the failure of any of them is equivalent to the failure of the entire "chain" of these blocks. Moreover, the comparator 13 can also be considered as an element included in the cascade of blocks 4, 7, 10, 16, since when it fails, the entire control channel is blocked and the system switches to a backup group of elements. The same processes occur when one of the comparators 14 or 15 fails. In this case, one of the channels 5, 8, 11, 17 or 6, 9, 12, 18 is blocked.

In the considered multi-zone integrating AC voltage regulator with automatic redundancy of control channels to increase its reliability, the integrator 3 can be performed by including several integrators operating in parallel. It should also be borne in mind that the adder 22 remains unreserved, which is advisable to run on the basis of a passive R-adder with a sufficient margin in operational characteristics. The adder 2 in real circuits is virtual (the summing point of the operational amplifier of the integrator), therefore, redundancy is not required.

Thus, due to the introduction of comparators 16, 17, 18 and the inclusion of an adder 22 at the output of the proposed device, the overwhelming majority of voltage regulator elements are in the “zone” of the effect of self-reservation, which leads to an increase in the reliability of the device as a whole.

In Fig.7 and Fig.8 shows the simulation results of the proposed device, made in the package "Matlab + Simulink".

With a “zero” failure of the first relay element 4 (FIG. 7b), the self-oscillating mode switches to the second relay element 5, and the power switch 20 is in the switching mode. The duration of the “packet” of the sinusoidal voltage at terminal 28 increases, however, the relative duration of this “packet” remains unchanged and corresponds to the operational state of the multi-zone integrating AC voltage regulator with automatic redundancy of control channels (Fig. 7a).

Fig. 8 shows, as an additional example, the signal diagrams of the multi-zone integrating AC voltage regulator with automatic redundancy of the control channels when the dynamic D-flip-flop 11 is in a malfunctioning state. In this case, the power switch 20 (terminal 28) goes into the off position, and the power switch switches into the static open position key 21 (terminal 29), and in the on / off mode - power switch 19 (terminal 27).

Thus, the introduction of a multi-zone integrating AC voltage regulator with automatic redundancy of the control channels of the third group of comparators 16, 17, 18 allows to increase the reliability of the system as a whole.

The considered device is supposed to be used in the automation system of the drying chamber 150EKR of the electric workshop of Chelyabinsk Pipe-Rolling Plant OJSC.

Claims (1)

A multi-zone integrating AC voltage regulator with automatic redundancy of control channels, containing a control signal source in series - an input terminal, a first adder, an integrator whose output is connected to the input of the first, second, and third relay elements, the outputs of which are connected to the inputs of the first, second, and the third comparator, respectively, the output of the first, second and third comparators are connected to the D-input of the first, second and third dynamic D-flip-flops, respectively , phase buses A, B, C connected to the corresponding inputs of the three-phase load with zero output through the first, second and third power switch, respectively, the control inputs of which are connected to the output of the first, second and third dynamic D-flip-flops, respectively, also containing a second adder, the output of which is connected to the second input of the first adder, the fourth, fifth and sixth comparators, the inputs of which are connected to the phase buses A, B, C, respectively, the output of the fourth, fifth and sixth comparator are connected to the C-input of the first, second o and the third dynamic D-flip-flop, respectively, characterized in that the seventh, eighth and ninth comparators are introduced into it, the outputs of which are connected to the corresponding inputs of the second adder, and the input of the seventh, eighth and ninth comparator is connected to the outputs of the first, second and third dynamic D -trigger accordingly.

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