RU2258952C2 - Digital identifier of accumulators charge parameters - Google Patents

Abstract

FIELD: automatic control.

SUBSTANCE: device has first and second analog-digital converters, first and second coefficients forming blocks, first and second multiplication blocks, counter, first and second integrator, control effect forming device, division block, buffer and registering block, while coefficients forming blocks are made in form of digital filters and all remaining blocks of device are made digital.

EFFECT: higher precision, higher resistance to interference.

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Description

The invention relates to automatic control, in particular to devices for identifying parameters of nonlinear inertial objects, and can be used in monitoring systems, identification in real time, including for adaptation to external conditions during battery charging.

In real conditions, safe fast charging of nickel-cadmium and nickel-metal hydride batteries has a wide range of parameters that depend on many factors (temperature, voltage fluctuations of the power supply network, industrial interference in the measuring circuits, etc.). (Article "Intelligent" charger for Ni-Cd batteries. "Radio", No. 1, 2001, p. 72). Identification of parameters (charging current and voltage on the battery) using a specialized processor, which includes an analog-to-digital converter (ADC), allows you to adequately determine the end time of optimal charging. The disadvantages of this device include the need to reprogram the optimal control period, disconnecting the battery from the charging circuit at the time of measuring the second parameter. This significantly reduces the speed of the adaptation process. The process of charging batteries in an industrial environment is subject to various industrial interferences. The constant impact on the charger circuit of a variety of random noise, including pulsed type, reduces the accuracy of the control circuit of the moment the battery stops charging.

A device is known for identifying parameters of a nonlinear object in a near optimal mode, in which there is no need to use a specialized computing device and reprogram it in manual mode (AS USSR No. 930266, G 05 B 23/02, 05.23.82). It allows real-time identification of the complex parameters of the investigated object, for example, the time constant T _i = R _i * C _i taking into account the nonlinearity of the characteristics of the controlled object, and increases the accuracy of the determination in the general case of the non-stationary parameter T _i (t). The disadvantages of this device are the need to excite the studied object with a specially formed symmetric test signal and low noise immunity of the analog aperiodic filter used for the continuous formation of the coefficients of the algebraic equation.

Closest to the proposed device is the identification of the time constant of a nonlinear object (AS USSR No. 991377, G 05 B 23/02, 23.01.83), which provides the possibility of continuous monitoring and measurement of the complex parameter Ti (t) in normal operation under random input signal. It contains the first and second blocks of the formation of coefficients, the first and second blocks of multiplication, the counter, the first and second integrators, the driver of the control action, the division block and the registration block, the outputs of the first block of the formation of coefficients connected respectively to the first inputs of the first and second blocks of multiplication, outputs which are connected to the inputs of the respective integrators, and the outputs of the integrators to the inputs of the division unit, the output of which is connected to the input of the registration unit, the first output of the second unit is formed Bani coefficients is connected to an input of the control action, the output of which is connected to the counter input.

The disadvantage of this device is low noise immunity, especially to pulsed type interference, which reduces the accuracy of estimating the moment when the batteries are charged, as well as the need for periodically adjusting the parameters of analog aperiodic filters used as blocks for the continuous generation of coefficients of algebraic equations with respect to unknown complex parameters of the battery charging technology.

The present invention provides for a technical result consisting in increasing the accuracy and noise immunity of the identifier.

The essence of the invention lies in the fact that in the identification device containing the first and second blocks of the formation of the coefficients, the first and second blocks of multiplication, the counter, the first and second integrators, the driver control action, the division unit and the registration unit, and the outputs of the first block of the formation of coefficients are connected respectively to the first inputs of the first and second multiplication units, the outputs of which are connected to the inputs of the corresponding integrators, and the outputs of the integrators to the inputs of the division unit, the output of which It is connected to the input of the registration unit, the first output of the second coefficient generation unit is connected to the input of the control action generator, the output of which is connected to the counter input, the first and second analog-to-digital converters and buffers are introduced, and the inputs of the first and second analog-to-digital converters serve as inputs of the device, and the outputs are connected to the corresponding blocks of the formation of coefficients, made in the form of digital IIR filters, the second output of the second block of the formation of coefficients is connected to vomu input buffer, a second input coupled to an output of the counter, and the output buffer - the second inputs of the first and second multiplying units, and all other digital devices blocks are made.

The drawing shows a diagram of the device. It contains analog-to-digital converters 1 and 2, the inputs of which serve as the corresponding inputs Y (t) and X (t) of the device, blocks 3 and 4 of generating coefficients of algebraic equations for unknown non-stationary complexes of battery parameters in the accelerated charging process, made in the form of digital IIR filters according to the conveyor type scheme, the first and second multiplication units 5 and 6, the first and second integrator 7 and 8, the division unit 9, the registration unit 10, the driver of the control action 11, the counter 12 and the buffer 13.

In this case, the input signal X (t) of the controlled object (battery charge circuit) is proportional to the voltage [U ₃ (t) + U _n (t)], where U _n (t) is the noise of the AC network, Y (t) is the output controlled an object signal proportional to the current in the charging circuit. The quantity Le (t) is the binary code of a number proportional to the reference voltage. The device operates as follows.

Controlled by the input X (t) and output Y (t) analog random signals in normal operation (battery charging) of the object without excitation, a special test signal is fed to the inputs of the ADC 1 and 2, the outputs of which are connected in parallel with the corresponding first and second inputs of digital IIR filters 3 and 4, which are used for discrete coefficient formation.

The second block 4 of the formation of coefficients generates a signal U ₀ (t _i ) and C ₀ (t _i ) = dU ₀ (t _i ) / dt _i , and the first block 3 of the formation of coefficients generates signals C ₀ (t _i ) and C ₁ (t _i ) = dCo (t _i ) / dt _i .

For certain parameters of blocks 3 and 4 of the formation of the coefficients, the signals U ₀ (t _i ) and U ₁ (t _i ) practically coincide with the controlled signals of the object X (t _i ) and Y (t _i ), respectively.

The received signals allow you to convert a nonlinear differential equation that describes an object

T _j * dy / dt + y (t) = Fj [x (t)], (1)

where x (t) is the input random signal;

y (t) is the output signal;

T _j = R _j * C _j - time constant, [s];

R _j and C _j - resistance and capacity in the battery charge circuit;

F _j is a unique continuous nonlinear function, to the following form:

T _j * C ₁ (t ₁ ) + C ₀ (t _i ) = F _j [U ₀ (t _i )]. (2)

The signals C _i (t _i ) and U ₀ (t _i ) are additionally modulated by multiplying by the signal U ₁ (t _i ), which is proportional to the first derivative of the input random signal X (t _i ), and is integrated over the time interval from t _i to t _{i +1} , and at these times, the signal U ₀ (t _i ) passes through the reference level U _e (t _i ), which is fixed by the driver 11 of the control action, to the separate inputs of which signals U ₀ (t _i ) and -U _e ( t _i ), and the output is connected to the counter input, registering N such transitions, changing the sign of the function Sign [U ₀ (t _i ) -U _e (t _i )].

The buffer 13 is opened and closed by the signal from the output of the counter 12. The right side of equation (2) in this case vanishes, so you can immediately determine the complex parameter of charging the battery, the time constant T _j (t _i ), which characterizes the inertia of the object.

The signals from the outputs of the digital integrators 7, 8 are fed to the division unit 9 and at the time t _{i + 1} , when [U ₀ (t _i ) -U _э (t _i )] = 0 or passes through zero, or N times like moments at the output of the division unit registers the value of the time constant T _j (t _i ) taking into account the nonlinear characteristics of the object.

The proposed digital identifier allows without additional reconfiguration of the coefficient generation blocks, multiplication blocks, integrators and the division block during normal operation with a random input signal with high accuracy to determine the battery charging parameters in the presence of industrial interference.

Claims (1)

A digital identifier for the parameters of charging the batteries, comprising the first and second blocks for generating the coefficients, the first and second blocks for multiplying, the counter, the first and second integrators, the driver of the control action, the division unit and the registration unit, the outputs of the first block for generating the coefficients connected respectively to the first inputs of the first and the second multiplication units, the outputs of which are connected to the inputs of the corresponding integrators, and the outputs of the integrators - with the inputs of the division unit, the output of which is connected to the input one of the registration unit, the first output of the second coefficient generation unit is connected to the input of the control action generator, the output of which is connected to the counter input, characterized in that it contains the first and second analog-to-digital converters and a buffer, and the inputs of the first and second analog-to-digital converters serve the inputs of the device, and the outputs are connected to the corresponding blocks of the formation of coefficients, made in the form of digital IIR filters, the second output of the second block of the formation of coefficients p dklyuchen to the first buffer entry, a second input connected to the counter output and the buffer output - to the second inputs of the first and second multiplication blocks and blocks all other digital devices are made.