Automatic voltage controller of synchronous generator. RU patent 2465717.

FIELD: electricity.

SUBSTANCE: invention may be used both for automation of equipment commissioning process and in a functional mode in devices for control of electric generators in order to get the required value of output parameters, in particular, to control generator excitation in order to weaken hazardous effect of overloads or transition processes, for instance, in case of spontaneous connection, removal or variation of a load. The automatic voltage controller of the synchronous generator comprises a voltage metre, the first summator, a PID controller, the second summator, an amplifier, a generator of initiating pulses, a set point generator, an analog to digital converter, a signal energy calculator, a delay unit, a control parameters calculator, an averaging unit. The control parameters calculator is arranged in the form of a processor device operating in accordance with the logic of ultra-fast annealing.

EFFECT: provides for automatic optimisation of synchronous generator excitation controller parameters by deviation of stator voltage and considerable reduction of transition processes energy.

The invention belongs to a class of devices of management of electric generators to obtain the required values of output parameters, in particular, to control the excitation of the generator to mitigate the harmful effects of overloads or transient processes, for example, when a sudden connection removal or amendment of the load and can be used for automation of process of input of the equipment in operation and the functional mode.

Stability and efficiency of the generating equipment enterprises, as well as the quality of electricity is largely determined by the perfection of systems of synchronous generator excitation control, generating electricity.

To achieve high quality results from the electricity, reduce the magnitude and duration of transient processes in synchronous generator, increase the efficiency and reduce the cost of commissioning of the equipment necessary to ensure the accuracy of adjustment of parameters field controller.

In existing systems of excitation control optimization of the parameters of the field control is performed at the stage of commissioning and at repeated start-UPS. The main parameters of the controller (amplification coefficients and constant time), affecting the stability of the regulation, the amount and duration of transient processes, entered service personnel manually, based on the gained experience, intuition and visual often evaluation parameters of the transitional process. The parameters of the regulator is also dependent on a number of electrical characteristics of the managed them generator, which may vary among the samples in the same party. Set parameters for the regulation, close to the optimal require a large number of iterations for the launch of the regulator, entailing significant time costs of the highly-qualified specialists.

The invention aims at solving the problem of reducing energy transition processes occurring during disturbances in the grid, due to optimization of parameters of the controller of synchronous generator excitation according to the variation of the stator voltage at the stage of commissioning and automation of this process.

Known device described in the patent of Russian Federation №2011264 from 26.06.91 «The way of automatic control of the synchronous generator excitation», for the same purpose as that of the invention, but not having with common characteristics and containing the generator carrier frequency, the block of division, with inputs for signals of the dividend and the divisor, block multiplication, with two entrances, the first and second identical channels, each of which contains a series-connected: modulator, with signal and reference inputs, demodulator, low frequency filter, bandpass, rectifier, smoothing filter, the output of the generator carrier frequency is connected to the reference inputs modulators of the first and second channels, signal inputs which are respectively entrances a device for feeding voltage signal and excitation current of synchronous generator, output snubber first channel is connected to the input signal of the dividend, and the output snubber the second channel - the entrance to signal divider block of division, the output of which is connected to one input of the block multiplication, and the input of which is the entrance to signal the first derivative of the generator voltage and output - output device.

The disadvantage of this device is that it does not is not the task of adapting an automatic regulator of a voltage on voltage deviation and the first derivative of the stator voltage controlled synchronous generator.

A device «Excitation Control Apparatus For Synchronous Machine» (Device control excitation of the synchronous machine), US patent No. 5,440,222 of 08.08.1995, which contains in its composition device Automatic voltage regulator (AVR (Automatic Voltage Regulator, AVR)containing meter voltage Detection Circuit), the first adder with and entrances, the first amplifier (Amp. Circuit A) with signal and managing inputs, phase compensation scheme (Phase Compensation Circuit) with signal and managing inputs, the second adder (Adding Circuit) with five entrances, second amplifier (Amp. Circuit), the third adder with two entrances, shaper setpoint (Reference Circuit), analyzer transition characteristics (Transfer Characteristic Detection and Operation Circuit) with two signal inputs, the input to control, access control and four alarm outputs, the scheme of the generation parameters of regulation (Control Constant Operation Circuit) with four signal inputs, control input and two outputs, generator initiating impulses (Step Signal Generation Circuit), input voltage meter is combined with the first input signal analyzer transition characteristics and is an input device for giving the signals of the stator voltage synchronous generator, the second signal analyzer input transient response is the input device to signal the rotor current, control inputs analyzer transition characteristics and schemes elaboration of the control parameters are combined and are input device to signal start the process of commissioning the meter output voltage is connected to the inverting input of the first adder to input of which is connected shaper setpoint, and the output of the first adder is connected to the signal input of the first amplifier, the output of which is connected to the signal input schematic phase compensation, the output of which is connected to the first input of the second adder, the inputs of which from second to fifth respectively input device for signaling system stabilizer (Power System Stabilizer, limiter system voltage/frequency (V/Hz Limiter), limiter of minimal excitation Poor Excitation Limiter), a limiter of the maximum excitation (Overexcitation Limiter), the output of the second adder is connected to the second input of the amplifier, the output of which is connected to the first input of the third adder, signal outputs analyzer economies in characteristics of the first four are connected to the same signal inputs schemes elaboration of the control parameters, the first and second control outputs which are connected to the control inputs of the first amplifier and schemes phase compensation, respectively, and the output of the control of the analyzer transition characteristics connected to the input of the generator initiating impulses, the output of which is connected to the second input of the third adder, the output of which is the output of the device.

According to the similarity of the majority of traits with by the invention and the similarity of purpose this device is selected as a prototype.

The main shortcomings of the prototype is the presence of systematic errors regulation stator voltage due to the absence of the integrating link in the controller voltage, and also in high energy transient process - because of the significant non-optimality and estimates of the parameters of regulation voltage.

The essence of the invention is automatic voltage regulator synchronous generator, containing a function of self-tuning during commissioning. The principle of control is based on the method of sequential stochastic optimization of its parameters (training), in which the objective function is the energy of the transition process, which is the response of the generator voltage on the triggering effect in the form of a rectangular pulse, changing the setpoint voltage of the synchronous generator.

Automatic voltage regulator synchronous generator contains a voltage meter 1, the input of which is the entrance automatic voltage regulator synchronous generator to signal the stator voltage, first adder 2 with and inputs, the PID controller 3 with four parametric and signal inputs connected to the first input of the second adder 4, the inputs of which from second to fifth respectively are the inputs automatic voltage regulator synchronous generator for signalling system stabilizer system limiter voltage/, limiter minimal excitation, a limiter of the maximum excitation, power 5, the output of which is the output of automatic voltage regulator synchronous generator, generator initiating impulses 6 with the control and signal outputs, the input of which is entrance to signal the start of the process of commissioning, shaper setpoint 7, analog-to-digital Converter 8, the energy of the signal 9 signal and managing inputs, the unit of the delay 10, the transmitter parameters regulation 11 with four outputs and two inputs, the unit averaging 12 with four inputs and four outputs the meter output voltage 1 is connected to the input of the analog-to-digital Converter 8 and the inverting input of the first adder 2, to input of which is connected shaper setpoint 7, to the input of which is connected to the signal output generator initiating impulses 6, the output of the first adder 2 is connected to the signal input PID 3, the output of the second adder 4 is connected to the input of the second amplifier 5, analog-to-digital Converter 8 is connected to the signal input of the transmitter signal energy 9, the output of which is connected to the block delay 10 and the first input of the transmitter parameters of regulation 11, exit delay block 10 is connected to the second input of the transmitter parameters of regulation 11, managing the output of the generator initiating impulses 6 is connected to the same input of the transmitter signal energy 9, outputs calculator the control parameters from the first through fourth respectively connected to the same inlet averaging, the outputs of which the first four are connected to the same parametric inputs PID.

Automatic voltage regulator synchronous generator operates as follows (figure 1).

As is known, the parameters of the dynamic object, in this case - energy system, consisting of excitation system, synchronous generator and the grid to influence its transient response - a response to the impact pulse of stepped form bearing information about dynamic properties of the investigated object.

Stator voltage of the synchronous generator is served on the voltage meter 1, output signal of which in the first adder 2 is compared with the value generated by the setpoint 7. Next, the resulting difference comes in the PID (proportional-integral-differential controller 3 with changeable parameters where the alarm is generated excitation control channel excitation adjustment stator voltage and its derivative. In the second adder 4 to the received signal added control signals of channels: system stabilizer, limiter system voltage/frequency limiter minimal excitation, a limiter of the maximum excitation coming from the respective inputs, then, the resulting signal is fed to the amplifier 5, with the release of which removed a signal proportional to the excitation voltage, coming next in the same system the generator.

During commissioning the automatic voltage regulator advanced signal the start of the process of commissioning the Start, including generator initiating impulses 6. Last produces the two: the signal control and signal setpoint changes ΔU 0 (t), which is rectangular pulse duration τ and repetition period T and amplitude ΔU 0 and T>τ . Front and duration of the signal control coincide with the setpoint signal of the ΔU 0 (t). Signal setpoint changes ΔU 0 (t) from the signal generator output initiating impulses 6 enters the shaper setpoint 7, which is the summation of constant setpoint U 0 , thereby set indignation in the power system.

Output signal measuring DC voltage 1 u[n] consistently arrives on analog-to-digital Converter 8 and transmitter signal energy 9, which makes calculation of the energy of the transition process during time t, and when the tone control: where E[k] - signal energy; N=t/T of d ; R d - sampling time signal, u 0 - the setting of the stator voltage, k - index of the generated pulse. After the time t and the value E[k] from the output of the transmitter energy 9 signal arrives at the input of the delay block 10 and at the first input of the transmitter parameters of regulation 11, the second input of which enters the value of the signal energy E[k-1], the calculated in the previous iteration.

The next period of the signal change settings ΔU 0 (t) (iteration) the above described process is repeated until the removal of the signal to Start. When this is consistent iterative refinement of the regulation before the end of the process of commissioning.

The duration of the signal to Start can be set, for example the number of iterations optimization k with the duration of the repetition period T and needed to achieve the required accuracy of calculation of parameters of the regulation.

Solver parameters regulation 11 is designed for correction of PID parameters-the regulator and may be implemented, for example, in the form processor unit, working on the known algorithm of ultra-fast annealing (training Boltzmann), described in [1], .104 and [2], consisting of the following operations.

Objective function for optimization, to a minimum, is the energy of the transition process E[k].

Step 1. Originally parameters of regulation {k P , T , T D , T } assigned known initial values, for example, on the basis of previous experience, the input automatic voltage regulators in operation. The minimal value of the energy is installed E min =E[0], specify the functionality of T[k]=E[k] / C, where C=const>1.

Step 2. Set the increment of one of parameters x i let {k P , T , T D , T }:

where is the previous value of the parameter x i , a i, a random variable uniformly distributed on the interval [0,1], A i ,B i - border range of values of the parameter A i < = x i < i , known in advance for all the parameters.

Step 3. Take the next value of the energy E[k+1].

If E[k+1]<E[k], the set E min =E[k+1], T[k+1]=E[k+1]/and leave the parameter x i without changes.

If E[k+1] & GE E[k], then produce the following operations:

Calculate the value of h=(E[k+1] - E[k]) / S.

If h>?, where β i is a random variable uniformly distributed over the interval [0,1], the set E min =E[k+1], T[k+1]=E[k+1]/and leave the parameter x i without changes. Otherwise, return the parameter x i in its original value: E min =E[k], T[k+1]=T[k].

Step 4. Choose the following option from the set {k P , T , T D , T ) and proceed to step 2. The process is repeated or to transmit the signal to Start, or to achieve a certain number of iterations k.

PIDknob 3 is a well-known device with transfer function:

where the p - Laplace operator, and can be implemented in the form of standard parts, amplifier, adder, integrator, differentiator and aperiodic link inputs integrator combined with the entrance of the differentiator and first entry adder and an entry for the PID integrator connected to the second input of the adder, the output of the differentiator is connected to the input aperiodic level, the output of which is connected with the third entrance of the adder, which is connected to the amplifier, the output of which is the output of the PID controller.

Voltage meter 1 is a known device, and may be implemented, for example, in the form of series-connected schema squaring, the entrance of which is the input voltage meter and integrator, the output of which is the output of the voltage meter.

The first and second adders 2 and 4 amplifier and 5 are known devices.

Generator initiating impulses 6 can be implemented, for example, in the form of series-connected generator of rectangular pulses with a given duration τ And repetition period T and amplitude ΔU 0 and T>τ And key and comparator, to control input key is the input, output the key is the signal output, and the output of the comparator - control the output of the generator initiating impulses.

Shaper setpoint 7 may be implemented as a adder to one input of which is connected a source of constant values other input and output of the adder is accordingly input and output shaper settings.

Analog-to-digital Converter 8 is a well-known device.

Transmitter signal energy 9 is intended for calculation values

where u[n] input, T D - sampling time signal, T - integration period, u 0 - the setting of the stator voltage, and can be implemented as a series-connected adder 13, first entrance of which is the input of the transmitter signal energy, and to the second input of which source is connected to a constant value (-u 0 +ΔU 0 (t)), schema squaring 14, adder with discharge 15 and register 16, working on the trailing edge, the output of which is the output of a transmitter of energy signal, and a clock input register 16, combined with the reset input adder with discharge 15, - control input of the transmitter signal energy.

Transmitter signal energy is as follows. The signal from the output of the circuit squaring 13 positive control signal to the control input of the transmitter signal energy accumulates a full adder with discharge 14. When moving the control signal with positive zero (falling edge), the register of 15 stores the value accumulated in the adder, and displays it on the output of the transmitter signal energy.

The delay unit 10 is designed to save energy values E[k-1], acting on the previous iteration, and can be implemented, for example, in the form of the register.

Block averaging 12 is used for suppression of noise control coefficients during the optimization process and can be implemented, for example in the form of four identical integrators working in parallel, entrance M-th integrator is a M-m input and output - M-m output block averaging, M=4.

Thus, as a result of consistent iterative correction, set the parameters PID {k P , T , T D , T } on the criterion of minimum energy of the transition process. Used to configure the famous ultra-fast annealing algorithm allows to optimize the parameters of the regulator, bringing them closer to the optimal, has good precision and eliminates the target function of education in a local minimum. When you type automatic voltage regulator synchronous generator in operation, the integrating link in the composition of the voltage regulator excludes permanent systematic error regulation stator voltage. Thanks to the proposed iterative algorithm of training, as well as the presence of unit averaging 12, estimation of parameters of the PID controller is an integrated circuit. Therefore, the proposed automatic voltage regulator has the function of self-tuning, commissioning and provides the minimum energy of the transition process.

Experience of realization of automatic voltage regulator showed that for optimization of parameters of PID with random the values close to optimal enough about k=200 iterations, and the energy of the transition process was reduced to four times compared with the settings regulator produced manually.

Sources used

1. Khaikin . network: a complete course: Per. s angl. - M: LLC «I.D. Williams», 2006.

2. Ingber L. Very fast simulated re-annealing // Mathl. Comput. Modelling. 12.1989. P. 967-973.

Automatic voltage regulator synchronous generator, containing a voltage meter, first adder with and inputs, the second adder with five entrances, amplifier, shaper setpoint generator initiating impulses, and the entrance measuring DC voltage is the entrance of the specified automatic voltage regulator, the meter output voltage is connected to the inverting input of the first adder to input of which is connected shaper setpoint to the input of which is connected to the signal output of the generator is initiating impulses, inputs second adder from second to fifth are the inputs specified automatic voltage regulator for signalling respectively system stabilizer system limiter signal voltage/frequency limiter minimal excitation and limit the maximum excitation, and the output of the second adder is connected to the input of the amplifier, characterized in that it additionally contains a transmitter parameters regulation with four outputs and two signal inputs, the unit of the delay, the PID controller with four parametric and one signal inputs, block averaging with four inputs and four outputs, serial connected analog-to-digital Converter and calculator energy of a signal with one signal and a single control inputs, as specified generator initiating impulses additionally contains a control output, and the specified shaper setpoint additionally provided with entrance, and the evaluator of the control parameters is made in the form of the CPU of the device running on ultra-fast annealing algorithm, output energy calculator signal is connected to the input of the delay block and to the first input of the transmitter parameters regulation, the output of the unit delay to the second input of the transmitter of the control parameters, the input of the analog-to-digital Converter output voltage meter, the output of the first adder - signal input PIDthe regulator output the last - to the first input of the second adder, managing the output of the generator initiating impulses to control input of the transmitter signal energy, four outputs of the transmitter parameters regulation - according to the same inlet averaging four outputs the last - to the same parametric inputs for the PID output is the output of the amplifier automatic voltage regulator synchronous generator and generator input trigger pulse input to signal the start of the process entering the controller into operation.