WO2024124265A1 - Procédé de commande d'un système technique-cascade d'observateur - Google Patents

Procédé de commande d'un système technique-cascade d'observateur Download PDF

Info

Publication number
WO2024124265A1
WO2024124265A1 PCT/AT2023/060435 AT2023060435W WO2024124265A1 WO 2024124265 A1 WO2024124265 A1 WO 2024124265A1 AT 2023060435 W AT2023060435 W AT 2023060435W WO 2024124265 A1 WO2024124265 A1 WO 2024124265A1
Authority
WO
WIPO (PCT)
Prior art keywords
variable
state
disturbance
current
control
Prior art date
Application number
PCT/AT2023/060435
Other languages
German (de)
English (en)
Inventor
Ngoc Anh Nguyen
Original Assignee
Avl List Gmbh
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Avl List Gmbh filed Critical Avl List Gmbh
Publication of WO2024124265A1 publication Critical patent/WO2024124265A1/fr

Links

Classifications

    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
    • G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
    • G05B13/04—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B13/00—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
    • G05B13/02—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
    • G05B13/04—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
    • G05B13/048—Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators using a predictor
    • G—PHYSICS
    • G05—CONTROLLING; REGULATING
    • G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B17/00—Systems involving the use of models or simulators of said systems
    • G05B17/02—Systems involving the use of models or simulators of said systems electric

Definitions

  • the present invention relates to a method for controlling a technical system with n state variables, at least one input variable acting on the system and influencing the temporal behavior of the n state variables, p disturbance variables acting on the system, where p is less than or equal to n, and at least one output variable to be controlled, wherein a controller determines a manipulated variable in predetermined control time steps from a control error which describes a deviation between a predetermined reference variable and the output variable, which is specified to the technical system as an input variable in order to regulate the output variable to the reference variable.
  • disturbance variables can affect a technical system to be controlled in different ways.
  • disturbance variables that affect the input, the output or the state of the system to be controlled (input disturbance, output disturbance, state disturbance).
  • input disturbance, output disturbance, state disturbance In addition to input, output and state disturbances, there are a number of other disturbances relevant to control engineering that can arise, for example, from model errors or parameter uncertainties.
  • disturbance and disturbance variable are used synonymously in the following explanations.
  • a “technical system” is understood to mean a system (device, system, device, machine, object, test bench, actuator, inverter, converter, DC-DC converter, DC/DC converter, etc.) that can be influenced by at least one input variable.
  • At least one input variable By influencing the at least one input variable, at least one state variable and/or at least one output variable of the technical system is influenced.
  • An output variable is typically a measurable or measured variable and is usually a variable that is to be regulated by the control system, for example a load current or a load voltage or another current or another voltage in a DC/DC converter.
  • Control means that the output variable is adjusted to a predetermined reference variable of the control system at any time or at any control time step.
  • a state variable is typically an internal variable of the technical system that is often not measurable or not measured, for example currents and/or voltages in the example of a DC/DC converter.
  • the input variable acts on the technical system via an actuator, whereby the actuator naturally depends on the type of input variable.
  • the controller of the technical system determines a control variable with which the actuator is controlled, for example in a DC/DC converter a PWM pattern for switching semiconductor switches in the DC/DC converter or switching pulses.
  • a classic method is the method of feedforward control, in which, to put it simply, a control variable determined by a controller is superimposed with a suitable compensation variable in order to (at least partially) compensate for the effect of the disturbance.
  • the compensation variable is typically derived from the disturbance. If, for example, an input disturbance affects the input of the system to be controlled, it is often sufficient to subtract the value of the input disturbance from the control variable determined by the controller in order to (at least partially) compensate for the effect of the input disturbance. In the case of disturbances affecting the state (state disturbances) or the output (output disturbance), however, it may be necessary to take into account the transfer behavior of the system to be controlled (i.e. how the input affects the output or the state) when determining a compensation variable.
  • a problem that has received a lot of attention in this context is the question of how to enable feedforward control in scenarios in which a disturbance cannot be measured directly and is therefore unknown.
  • Various approaches are also known for solving this problem, with the method of disturbance observation in particular proving to be a universally applicable and often particularly precise approach.
  • an estimator in control engineering and subsequently referred to as an "observer” or specifically as a “disturbance observer"
  • an estimator in control engineering and subsequently referred to as an "observer” or specifically as a “disturbance observer”
  • it can be advantageous or even necessary to determine an estimate of the disturbance e.g. because the measurement of the disturbance is delayed and thus slow or is distorted due to dirt effects that occur in practice.
  • control quality i.e. in particular high control accuracy, a short rise time, low overshoot or the use of little control energy
  • a disturbance affects a system to be controlled and the disturbance is to be estimated using a disturbance observer and then compensated on the basis of the estimate, it is often necessary to take control quality requirements into account when designing disturbance observers.
  • the control accuracy evaluates the deviation or control error between a variable to be controlled, usually a Output variable of the system to be controlled and a reference variable (a specified setpoint) specified for this variable to be controlled.
  • a high level of control accuracy means a low, ideally negligible, control error.
  • disturbances are often a major cause of insufficient control accuracy.
  • the shifted variable "output variable plus output disturbance” is controlled instead of the actual output variable to be controlled, which results in a deviation between the actual output variable and the reference variable by the amount of the output disturbance.
  • this is referred to as an "offset".
  • Real-time capability means that the control variables can be determined by the controller within a specified time period.
  • the independent claims describe a method for controlling a technical system and a technical system.
  • the invention assumes a technical system with n state variables, with at least one input variable acting on the technical system and influencing the temporal behavior of the n state variables, p disturbance variables acting on the technical system, where p is less than or equal to n, and at least one output variable to be controlled.
  • the at least one input variable and/or the at least one output variable and/or at least one of the n state variables are measured.
  • a controller determines a manipulated variable in predetermined control time steps from a control error that describes a deviation between the reference variable and the output variable, which is then specified to the technical system as an input variable for control.
  • such a system for determining current state estimates for a number of at least m state variables of the n state variables of the technical system during a current control time step by means of a state observer, where m is greater than or equal to one and less than or equal to n.
  • current disturbance variable estimates for the p disturbance variables are determined based on this, taking into account a current control error and/or at least one past control error, from the current at least m current state estimates determined with the state observer, from known at least m past state estimates from a past control time step, and, if m is less than p, from at least a number of pm current measured values of the input variable and/or the output variable and/or of state variables for which no state estimate has been determined by the state observer.
  • These current disturbance estimates are fed to the controller at each time step so that the controller can take the disturbance estimates into account when determining a current manipulated variable for control.
  • the procedure according to the invention is based on the insight that particularly accurate estimates of disturbances can be determined by using control errors as additional correction terms in a disturbance observer.
  • control errors as additional correction terms in a disturbance observer.
  • the invention makes it possible to combine this remarkable insight in a simple and efficient manner with other advantageous approaches to determining disturbances, such as comparing state estimates from different control time steps.
  • the structure according to the invention consisting of a state observer and a disturbance observer, is precise and computationally efficient, has a low level of complexity and is easy to parameterize.
  • At least one disturbance variable acts as a state disturbance or as an input disturbance and influences the temporal behavior of the n state variables and/or at least one disturbance variable acts as an output disturbance and is superimposed on the at least one output variable to be controlled.
  • Another important advantage of the method according to the invention is its flexibility.
  • the invention can be adapted precisely to different applications with usually only minor changes.
  • the state observer can determine state estimates for all of the n state variables, for which at least p or more than p measured values of the input variable and/or the output variable and/or state variables can be supplied to the state observer in order to meet particularly high accuracy requirements.
  • a control time step immediately preceding the current control time step can be used as a past control time step in order to be able to provide accurate estimates of the disturbance variables even in highly dynamic or very fast technical systems, i.e. in systems with small time constants.
  • a technical system has large time constants, it can be advantageous to use control time steps that are further apart from each other for the estimation.
  • a plurality of past control time steps can also be used, for example to calculate an average over a The temporal course of the state variables must be taken into account when estimating disturbances in the disturbance observer.
  • a deviation between two consecutive state estimates can be determined, and this deviation can be used to determine the disturbance variable estimates, according to the invention, as described, taking into account at least one control error.
  • This deviation can preferably be determined by forming the difference between consecutive state estimates.
  • This approach is based on the knowledge that, on the one hand, a control error can be a measure of an effective disturbance variable, but on the other hand, a deviation between two consecutive state estimates can also represent such a measure. By combining two such measures, the accuracy of the resulting estimates can be improved in a special way. Since the estimated disturbance variables are taken into account in the control according to the invention, the accuracy advantages mentioned have a direct impact on the control of the output variable.
  • Another point in which the invention can be flexibly adapted to specific requirements of special applications is the way in which the control errors are taken into account when estimating the disturbance variables.
  • a particularly advantageous approach has proven to be to take the current control error into account as a current control error weighted by at least one linear weighting factor when determining the disturbance variable estimates.
  • this creates a connection to the state control that is well known from control engineering.
  • the weighting factors mentioned can be selected in a particularly simple manner using means for designing state controllers, for example using the well-known Ackermann formula.
  • a significant advantage of the structure according to the invention comprising cascaded observers and a controller as described above lies in the continued simplicity of the resulting overall system and the associated short execution times, whereby in particular the achievable control accuracy is not impaired.
  • control circuit for controlling a technical system in which a control unit is provided for implementing the method steps according to the invention.
  • a control unit for controlling battery systems, in particular battery systems for electric drive trains.
  • HiL test benches hardware-in-the-loop test bench systems
  • Components of electric drive trains include battery systems (energy storage devices such as accumulators or batteries or on-board batteries), but also electric motors, transmissions, drive shafts and electrical converters.
  • HiL tests In HiL tests, physically existing components are actually built on a HiL test bench and physically non-existent components are replaced by corresponding mathematical simulation models. Highly dynamic actuators are used to adjust reference values or time profiles of reference values that result from a calculation of the simulation models in real time during operation of the HiL test bench and that describe the temporal behavior of the physically non-existent components.
  • the environment expected in real operation can be simulated or "emulated" for components to be tested that are actually present on the HiL test bench.
  • the load on the HiL test bench corresponds to the real load expected in real operation, even though several components are not physically present.
  • a highly dynamic actuator can be understood as a technical system to be controlled.
  • a highly dynamic actuator can be in the form of an electrical power converter, e.g. as a step-up converter, step-down converter (also called a buck converter, “interleaved buck converter”), inverter, frequency converter, etc., which simulates the load of a battery system to be tested, e.g. an on-board battery.
  • the load of a battery system to be tested typically results from the operating state of the electric drive train supplied by the battery system and the electrical energy consumed by the electric drive train, whereby the electric drive train is not physically present in the case of a HiL test and is advantageously simulated in a simulation model.
  • battery test systems must also be designed to be more dynamic, precise and computationally efficient.
  • a wide variety of disturbances can also affect a battery test system, whereby the often unknown effect of the battery system to be tested on the highly dynamic actuator can represent a significant disturbance.
  • the sometimes very high sampling rates used in modern electric drive trains can, in combination with complex simulation models and complex disturbance observers, lead to the problems mentioned above with regard to Real-time capability.
  • battery test systems are a predestined field of application for the method according to the invention, which is explained in detail below.
  • Fig.1 a coupling plan for controlling a technical system according to the state of the art
  • Fig.2 shows a coupling plan according to the invention for controlling a technical system
  • Fig.3 a bidirectional DC/DC converter
  • Fig.4 an equivalent circuit diagram of a bidirectional DC/DC converter
  • Fig.5a, 5b show results obtained with the method according to the invention and with a method according to the prior art.
  • Fig.1 shows a typical control loop 200 known from the prior art for controlling a technical system 1.
  • the technical system 1 shown in Fig.1 has n> 1 state variables xi,...,x n and at least one input variable u, which acts on the technical system 1 and influences the temporal behavior of the n state variables xi,...,x n .
  • the disturbance variables wi, W2, W3 also act on the technical system 1. However, within the scope of the invention it is not necessary that all disturbance variables wi, W2, W3 always act; it is sufficient if at least one disturbance variable wi, W2, W3 acts.
  • the disturbance variable wi acts as an input disturbance, the disturbance variable W2 as a state disturbance and the disturbance variable W3 as an output disturbance.
  • a state variable xj (i serves here as an index to generally reference the n state variables) is used to describe the internal behavior of a technical system 1 .
  • state variables xi,...,x n are required to characterize the state or to characterize the internal behavior of a technical system 1.
  • the number of state variables xi,...,x n determines the order of a technical system 1.
  • the aim is to use a controller R to adjust an output variable y of the technical system 1 to a value specified by a given reference variable r, i.e. to adjust the output variable y to be controlled to the reference variable r.
  • a manipulated variable v which is specified to the technical system 1 as an input variable u
  • control loops such as the one shown in Fig.1
  • the at least one input variable u and/or the at least one output variable y and/or at least one of the n state variables xi,...,x n can be measured and further processed for control.
  • one or more suitable measurement data acquisition units can be provided, such as sensors or voltage sensors or current sensors or speed sensors or position sensors, etc., which is of course well known to the person skilled in the art in the field of control engineering.
  • control loops such as the one shown in Fig.1
  • the input variable u and the output variable y of the technical system 1 are measured, but it is also conceivable that additionally selected state variables Xj are also measured, or that instead of the input variable u and the output variable y, only state variables Xj are measured.
  • an output variable y can also correspond to a state variable Xj, or can also depend on several state variables Xj.
  • An output variable y can be a scalar output variable y, as is common in SISO systems (single-input, single-output).
  • An output variable y can also be a vector output variable y, as is common in MIMO systems (multiple-input, multiple output).
  • the reference variable r is usually specified continuously, which leads to a temporal progression of the reference variable r.
  • continuous is to be understood as a specification of the reference variable r in predetermined control time steps of the control.
  • sampling is carried out with a sampling time T s .
  • a state observer ZB is also provided for estimating state variables Xj and disturbance variables wi.
  • control laws can be used, such as model predictive control (MPC), adaptive control (AC), linear quadratic regulators (LQR), or other optimization-based control algorithms, but also control algorithms such as sliding mode control, backstepping control or flatness-based controllers, whereby the choice of the control law is irrelevant for the invention.
  • MPC model predictive control
  • AC adaptive control
  • LQR linear quadratic regulators
  • control algorithms such as sliding mode control, backstepping control or flatness-based controllers, whereby the choice of the control law is irrelevant for the invention.
  • the controller R can also directly access a measured output variable y, which is indicated by the dashed input in the controller R.
  • a measured output variable y which is indicated by the dashed input in the controller R.
  • state observers ZB of the so-called Luenberger type are often used as state observers ZB for estimating state variables Xj and disturbance variables wi, although other observer types can also be used, such as Kalman filters.
  • a combined estimation of state variables Xj and disturbance variables wi as shown in Fig.1 represents an approach known in the state of the art.
  • disturbance variable models i.e. models of the dynamic or temporal behavior of the disturbance variables wi to be estimated
  • the idea is usually implemented to extend an existing mathematical model of the technical system 1 to be controlled by the aforementioned disturbance variable models, so that the disturbance variables wi are considered as further state variables Xj in the extended state space model.
  • a vector-valued time-discrete difference equation and a vector-valued time-continuous differential equation can be given as linear or non-linear equations.
  • Disturbance estimates also be subjected to filtering.
  • Fig. 2 shows a block diagram of a control loop 100 according to the invention with a state observer ZB and a disturbance variable observer SB separate from the state observer ZB.
  • the disturbance variable observer SB and the state observer ZB form a cascade structure.
  • the statements made in Fig.1 regarding disturbance variables wi, w 2 , W3, state variables xi,...,x n , input variable u, output variable y, controller R, manipulated variable v, vector notation, measurement, etc. are still fully valid with regard to the coupling plan shown in Fig.2.
  • the state observer ZB determines fewer than p state estimates, so that m is smaller than p.
  • the disturbance variable observer SB can be supplied with measured values of the input variable u and/or the output variable y and/or state variables xi,...,x n , for which no state estimate x lik ,x 2ik , ...,x mk has been determined by the state observer ZB, instead of the pm state estimates that are missing in this case.
  • estimates for all n state variables can also be determined and supplied to the disturbance variable observer SB, so that the disturbance variable observer SB can access a complete estimate of the state of the technical system 1.
  • the disturbance variable observer can also SB can also be supplied with a combination of state estimates and measured values, which in total amounts to more than p quantities, e.g. p state estimates and np measured values.
  • a core idea of the method according to the invention is to first generate correct state estimates X k using a state observer ZB and without explicitly taking into account the effective disturbance variables wi.
  • the determined state estimates X k are used together with known, past at least m state estimates X fe-7 to determine the disturbance variable estimates.
  • successive state estimates X ⁇ Xfc-i can be compared with each other, whereby it is checked whether the relationship between the compared, successive state estimates X ⁇ -i e corresponds to a disturbance-free relationship that would arise in a disturbance-free scenario, or whether there is a deviation from this disturbance-free relationship.
  • control errors e y as additional correction terms in the disturbance variable observer SB.
  • the control errors e y mentioned preferably weighted by a linear weighting factor L, can be taken into account when calculating the disturbance variable estimates.
  • control errors e y represent a further measure for the disturbance variables w to be estimated, in particular since in a technical system 1 controlled by a suitably designed controller R, in the undisturbed case, no or only insignificant control errors e y often occur.
  • the m state estimates X [x n x 2 , ...,x m ] 7 do not have to correspond to the first m state variables xi,...,x m , but can be any m state variables xi,...,x m selected from the total of n state variables xi,...,x n .
  • This circumstance makes it possible, in particular, to significantly reduce the complexity of state observers ZB.
  • state space models are extended by disturbance variable models, typically all states of the extended model must be estimated. Within the scope of the invention, it can therefore be sufficient, for example, even in a complex system 1 with a large number of state variables Xj, to estimate just one state variable Xj if, for example, only one disturbance variable wi is at work.
  • Control loops 100 with a cascade of a state observer ZB and a disturbance variable observer SB are particularly suitable for controlling bidirectional DC/DC converters 10 as a technical system 1, such as those used on HiL test benches, e.g.
  • Fig.3 discloses a possible embodiment of a technical system 1 in the form of a DC/DC converter 10 with an electrical load 5.
  • the DC/DC converter 10 takes on the role of the technical system 1.
  • the electrical load 5 represents a test object to be tested (also known as a “unit under test” or “UUT”), with the case of an electrical load 5 in the form of a battery system being considered below.
  • the electrical load 5 can also be an (at least partial) electrical drive train of a vehicle, or comprise certain drive train components of an electrical drive train, or even represent just a single drive train component of an electrical drive train, such as a power converter or an electrical machine.
  • the DC/DC converter 10 provides the electrical load 5 with a load current i, which, in conjunction with the load 5, produces a load voltage V2 at the output of the DC/DC converter 10.
  • the DC/DC converter 10 shown in Fig.3 comprises the half-bridges HBi, HB2, HB3, HB4.
  • a direct voltage vo is present at the inputs Ei, E2 of the DC/DC converter 10, which is smoothed by a smoothing capacitor Co that is usually present.
  • a three-phase alternating voltage AC is rectified by means of a rectifier 4 to an input direct voltage vo.
  • the DC/DC converter 10 is constructed as a four-phase synchronous converter.
  • the DC/DC converter 10 can also have more or fewer phases.
  • the applicability of the present invention is not restricted by this.
  • the DC/DC converter 10 consists of parallel half-bridges HB1, HB2, HB3, HB4 and associated chokes Li, L2, L3, L4, whose phase currents i Li , ii2, ii_3, ii_4 are each controlled by the switching behavior of the associated half-bridge HB1, HB2, HB3, HB4.
  • the half-bridges HB1, HB2, HB3, HB4 each consist of an upper power switch S01, S02, S 0 3, S 0 4, and a lower power switch S u i, Su2, Su3, Su4, whereby the phases with the associated chokes Li, L2, L3, L4 are each connected between an upper and lower circuit breaker. Furthermore, as usual, freewheeling diodes D oi , D u i, D 0 2, D U 2, D 0 3, D U 3, D 0 4, D U 4 are provided in parallel with the circuit breakers.
  • one half-bridge HBi, HB2, HB3, HB4 and one choke Li, L2, L3, L4 are provided for each phase, with the chokes Li, L2, L3, L4 being connected on the one hand between the upper power switches S01, S02, S 0 3, S 0 4 and the lower power switches Sui , Su2, Su3 , Su4 with one half-bridge HB1, HB2, HB3, HB4 each, and on the other hand being connected to one another on the output side.
  • the output current is therefore the sum of the respective phase currents i Li , ii2, ii3, ii4.
  • the ohmic resistances of the chokes Li, L2, L3, L4 are neglected in Fig.3, but can also be taken into account (as later in Fig.4).
  • an output filter F which filters the output current in the desired manner, for example smoothes it.
  • the output filter F is designed in the form of an output-side smoothing capacitor C2 and an output inductance L.
  • the output filter F receives an output current of the DC/DC converter 10 or an output voltage vi as input variable(s) and filters these.
  • control unit 2 The power switches S01, S02, S 0 3, S 0 4, S ui , Su2, S U 3, S U 4 of the half-bridges are controlled by a control unit 2.
  • the observation and control according to the invention can be implemented on a control unit 2.
  • corresponding control units 2 are typically also provided in other technical systems 1, not only in the DC/DC converter 10 under consideration.
  • the upper power switches S01, S02, S 0 3, S 0 4 and the corresponding lower power switches Sui, S U 2, S U 3, S U 4 of a half-bridge HB1, HB2, HB3, HB4 are basically switched alternately to prevent potentially damaging short circuits in the half-bridges.
  • a control method is implemented in the control unit 2, usually a well-known pulse width modulation (PWM).
  • PWM pulse width modulation
  • pulse width modulation can be used to specify a duty cycle d, which describes the duration of the input voltage vo being switched through via a half-bridge in relation to a specified switching period T s .
  • the DC/DC converter 10 can of course also be designed in a different design or circuit topology, e.g. with fewer or more strands, with fewer or more power switches (also per half bridge), etc. It is also conceivable that the rectifier 4 is integrated in the DC/DC converter 10. In every design, however, the DC/DC converter 10 comprises at least one power switch which is controlled by a control unit 2 in order to set a load current i.
  • the DC/DC converter 10 To operate the DC/DC converter 10, it can be provided to determine the load current i and/or the load voltage V2, e.g. by measurement or calculation or by an observer based on other known quantities, and to supply the determined load current i and/or the load voltage V2 to the control unit 2, as in the embodiment of Fig. 3.
  • the measurement of the load voltage V2 in particular often proves to be difficult, and due to the usually necessary cabling of measurement setups used for measurement, the actual temporal behavior of a load voltage V2 can often only be inadequately represented in a measurement.
  • an emulation model 3 of a component to be emulated (UUT) is provided in the control unit 2, for example a drive train model for describing the temporal behavior of an electric drive train or a battery model.
  • the emulation model 3 simulates the behavior of the component(s) to be simulated and typically calculates a reference variable r, e.g. in the form of a reference current iR (battery current). Such a reference current iR can subsequently be used as a reference variable r or as a reference variable time curve for controlling the load current i.
  • a reference variable r can also be specified in another way, e.g. by an operator or by reading from a table. In this case, an emulation model 3 is not necessary.
  • An emulation model 3 does not necessarily have to record input variables, but can also determine a reference variable r without externally specified input variables.
  • i 2 ,v 1 ,v 2 are the sum of the phase currents, the output current, the output voltage and the measured load voltage.
  • v 0 ⁇ d stands for the input variable u, which is the product of the intermediate circuit voltage v 0 and the duty cycle d.
  • X, A, B, E, C which are common in linear control technology, are introduced for the state vector, the dynamic matrix, the input vector, the disturbance input vector and the output vector.
  • the load voltage V2 acts as a disturbance variable w on the model.
  • the load current i represents the output variable y to be controlled.
  • the subscript d represents the time-discrete model description
  • the index k records the time-discrete control time steps already mentioned.
  • a system such as the above linear difference equation can result from the modeling of the most diverse technical systems 1, which indicates the universal applicability of the invention.
  • a linear, time-discrete model as above can also result from the Linearization of any nonlinear model, so that the class of models or technical systems 1 to which the invention can be applied does not need to be restricted in principle.
  • a non-linear or linear control law can be specified for the above model, e.g. in the form of a state controller well known in control engineering, in which the state vector X of the system to be controlled is mapped directly to the manipulated variable u by means of a controller gain K x .
  • a variety of methods and approaches are available for selecting the controller gain K x , such as the state controller design according to Ackermann.
  • the estimated disturbance values determined are advantageously taken into account in the controller R when determining the manipulated variable. It should be noted that this procedure in particular opens up the possibility of using control laws without integral components. Integrating controllers are typically used to suppress input disturbances. However, if, as provided for in the context of the invention, all effective disturbances are estimated and taken into account by means of their estimate and compensated in a suitable manner, integrators in the controller R can often be dispensed with, which brings with it a variety of advantages in terms of dynamics and tendency to oscillate in the resulting control loops (for example, integrators in controllers R can cause larger ripples and larger overshoots in step responses).
  • a state controller K x is used to adjust an output variable y to a given reference variable r
  • u r represents a value of the manipulated variable u k that is required to keep the state vector X in the reference state vector X r .
  • this reference state vector X r is to convert the state vector X into a state vector X r in which the originally posed control problem of adjusting the output variable y to the reference variable r is solved.
  • the reference state vector X r is thus an auxiliary variable that is derived from the given reference variable r.
  • a state observer ZB can be designed for the above model to determine the state estimate X k .
  • Z k stands for an auxiliary state from which the estimate X k for the state vector X k to be estimated can be determined according to the second of the above equations
  • y k stands for an estimate of the output variable y determined from the estimate X k .
  • the matrix D can correspond to the already known output matrix C, but can also be chosen differently, e.g. for reasons of observer design.
  • the state observer ZB determines the state estimates X k based on the output variable yk and the input variable Uk of the technical system 1. These variables, output variable yk and input variable Uk, are made available to the state observer ZB in practical implementation as measured variables.
  • p acting disturbance variables wi it was recognized that in many cases relevant to practice, in the case of a number of p acting disturbance variables wi, it is necessary to provide a state observer ZB with at least p measured variables, e.g. the input variable u and/or the output variable y and/or state variables xi...x n , in order to be able to determine the desired state estimate.
  • Af (Z - E d (DE d yD)A d - [Q ff] _ D( j _ E y DEd y D ) Ad .
  • X k+ 1 A d X k + B d u k + E d w k and is not restricted to the DC/DC converter under consideration.
  • M -E d (DE d + R(I - (DE d DE d ) can be used.
  • other approaches to setting up the observer equations of the state observer ZB can also be used, such as sliding mode observers, or Kalman filters or other observers.
  • the decisive factor is that the state observer ZB allows an exact estimate of the state vector to be determined without explicitly considering the disturbance variables w, from which the desired disturbance variable estimates can be determined in a next step in the disturbance variable observer.
  • the described type of estimation has several disadvantages, including the fact that the estimate of the disturbance variables w k only becomes correct once the estimate of the state vector x k has converged. If it is not possible to ensure rapid convergence, it can sometimes take a considerable amount of time before correct disturbance variable estimates can be provided.
  • the system of equations from which the unknown W k can be determined.
  • the second equation of the above system of equations is inserted into the first equation, the calculation rule after transformation is for the disturbance vector to be estimated. This shows the effect of the additional correction term based on the control error.
  • a significant advantage of formulating the disturbance observer SB in the form of two separate difference equations is that the selection of the gain factors L ⁇ and l 2 (not to be confused with the inductances Li , l_2, L3, L4) to be determined can be carried out in a particularly efficient manner.
  • Figures 5a and 5b show results that were achieved when controlling a DC/DC converter 10 as shown in Figure 3, once by means of the control circuit 200 from Figure 1 according to the prior art, and once by means of the control circuit 100 according to the invention as shown in Figure 2.
  • the dashed line (state of the art) was achieved without estimating the effective disturbance variable w, the solid line with estimating the effective disturbance variable w (invention). It is clear that with the method according to the invention, a higher control accuracy can be achieved and a faster transient response is possible.
  • Fig.5b shows the steady state of the control task described in Fig.5a. It can be seen that the invention (solid line) enables precise control of the specified current of 100A even without integrating components in the controller. The method according to the state of the art (dashed line) leads to a remaining control deviation, which is extremely undesirable in practical use for obvious reasons, especially in test systems, which are known to have particularly strict accuracy requirements.
  • a state model is provided to describe the temporal change of the n state variables xi...x n , which is expanded to include further model components, such as models of output variables with an error component and a dynamic component or disturbance variable models, for example to describe disturbance variables wi and output variables y and state variables xi...x n in a common model. If external disturbance variables remain in such an overall model despite the inclusion of disturbance variables or output variables in an expanded state vector, for example because not all disturbance variables can be described in a model and included in the overall model, the present invention can also be applied to such a model.
  • output variables y to be controlled in particular are often strongly influenced by disturbance variables, so that it is difficult to provide a suitable description of the dynamic behavior for an output variable y to be controlled, which is usually necessary for the design of controllers.
  • the output variable model has a dynamic component that depends on the output variable y and an error component that depends on a disturbance that influences the temporal behavior of the output variable, so that the invention in question can be used in an advantageous manner, based on the use of a disturbance observer and a state observer, to determine estimated values for the disturbance and then take these into account in a control system.

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Health & Medical Sciences (AREA)
  • Artificial Intelligence (AREA)
  • Computer Vision & Pattern Recognition (AREA)
  • Evolutionary Computation (AREA)
  • Medical Informatics (AREA)
  • Software Systems (AREA)
  • Feedback Control In General (AREA)

Abstract

L'invention concerne un procédé précis et efficace en terme de calcul pour estimer et compenser des variables de perturbation (w1...wp) agissant sur un système technique (1) à commander avec n variables d'état (x1...xn), dans lequel procédé un observateur d'état (ZB) est utilisé pour déterminer des estimations d'état actuel x̂1,k, x̂2,k, ..., x̂m,k pour un nombre d'au moins m variables d'état (x1... xm), et, sur la base desdites estimations d'état x̂1,k, x̂2,k, ..., x̂m,k déterminées par l'observateur d'état (ZB), un observateur de variable de perturbation (SB) est utilisé pour déterminer, en tenant compte d'une erreur de commande ey, k, des estimations de variable de perturbation Ŵ1,k, Ŵ2,k, Ŵp,k pour les variables de perturbation (w1...wp).
PCT/AT2023/060435 2022-12-13 2023-12-12 Procédé de commande d'un système technique-cascade d'observateur WO2024124265A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ATA50951/2022A AT526758A1 (de) 2022-12-13 2022-12-13 Verfahren zur Regelung eines technischen Systems - Beobachterkaskade
ATA50951/2022 2022-12-13

Publications (1)

Publication Number Publication Date
WO2024124265A1 true WO2024124265A1 (fr) 2024-06-20

Family

ID=89321494

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/AT2023/060435 WO2024124265A1 (fr) 2022-12-13 2023-12-12 Procédé de commande d'un système technique-cascade d'observateur

Country Status (2)

Country Link
AT (1) AT526758A1 (fr)
WO (1) WO2024124265A1 (fr)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009086220A1 (fr) * 2007-12-21 2009-07-09 University Of Florida Systèmes et procédés pour une commande prédictive de modèle sans décalage
US20110060424A1 (en) * 2009-09-10 2011-03-10 Honeywell International Inc. System and method for predicting future disturbances in model predictive control applications
US20210124316A1 (en) * 2019-10-25 2021-04-29 Dow Global Technologies Llc Nonlinear Model Predictive Control of a Process

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT513776B1 (de) * 2014-04-08 2015-09-15 Avl List Gmbh Verfahren und Regler zur modellprädiktiven Regelung eines mehrphasigen DC/DC-Wandlers
AT521666B1 (de) * 2018-07-09 2022-02-15 Avl List Gmbh Verfahren und Vorrichtung zur Kompensation von Störgrößen

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2009086220A1 (fr) * 2007-12-21 2009-07-09 University Of Florida Systèmes et procédés pour une commande prédictive de modèle sans décalage
US20110060424A1 (en) * 2009-09-10 2011-03-10 Honeywell International Inc. System and method for predicting future disturbances in model predictive control applications
US20210124316A1 (en) * 2019-10-25 2021-04-29 Dow Global Technologies Llc Nonlinear Model Predictive Control of a Process

Non-Patent Citations (3)

* Cited by examiner, † Cited by third party
Title
"Offset-free reference tracking with model predictive control", AUTOMATICA, vol. 46, pages 1469 - 1476
MAEDER, U.MORARI, M.: "Offset-free tracking MPC: A tutorial review and comparison of different formulations", EUROPEAN CONTROL CONFERENCE (ECC, 2010
PANNOCCHIA, G.: "Offset-free MPC explained: novelties, subtleties, and applications", 5TH IFAC CONFERENCE ON NONLINEAR MODEL PREDICTIVE CONTROL, 2015

Also Published As

Publication number Publication date
AT526758A1 (de) 2024-06-15

Similar Documents

Publication Publication Date Title
DE10196372B3 (de) Adaptiver rückgekoppelter/vorwärtsgekoppelter PID-Controller
EP2534748B1 (fr) Contrôle d'un convertisseur multi-niveaux modulaire avec un observateur pour les courants et un estimateur pour l'énergie du circuit intermédiaire
AT513776B1 (de) Verfahren und Regler zur modellprädiktiven Regelung eines mehrphasigen DC/DC-Wandlers
AT513189A2 (de) Verfahren zur Ermittlung eines regelungstechnischen Beobachters für den SoC
DE102015111082A1 (de) Verfahren und Vorrichtung zur Steuerungsoptimierung eines Schaltspannungsreglers
DE112009004058T5 (de) Verfahren und Systeme für die Komponentenwertschätzung inStromversorgungen/Leistungsumsetzern
WO2009152840A1 (fr) Procédé de réglage pour une installation de transmission de courant continu haute tension présentant un circuit intermédiaire à courant continu et des convertisseurs automatiques
WO2021035269A1 (fr) Procédé et régulateur de commande prédictive, fondée sur un modèle, d'un convertisseur couplé
EP3308442B1 (fr) Procédé de paramétrage assisté par ordinateur d'un changeur de fréquence dans un réseau électrique
WO2024124265A1 (fr) Procédé de commande d'un système technique-cascade d'observateur
EP2481146B1 (fr) Procédé et dispositif de réglage d'un convertisseur
WO2024124266A1 (fr) Procédé de commande d'un modèle variable de sortie de système technique
DE102019130971A1 (de) Computerimplementiertes Verfahren zur Simulation einer elektrischen Schaltung
EP2425522B1 (fr) Procédé de régulation d'un convertisseur, tenant compte de la temporisation du réglage et de la mesure, à l'aide d'un observateur
DE4029117A1 (de) Vorrichtung zum elektrischen schweissen mit digitaler regelung und einstellung
EP2534749B1 (fr) Contrôle d'un convertisseur multi-niveaux modulaire avec un observateur pour les courants et un estimateur pour l'énergie du circuit intermédiaire
DE10253865B4 (de) Verfahren zur Ermittelung von ein mehrphasiges elektrotechnisches Betriebsmittel charakterisierenden elektrischen Größen
EP2517348B1 (fr) Procédé de régulation d'un système variant dans le temps
AT521666A1 (de) Verfahren und Vorrichtung zur Kompensation von Störgrößen
DE4310778C2 (de) Verfahren zur zeitdiskreten Regelung des Stromes eines über einen Wechselrichter gespeisten Asynchronmotors
EP3297151A1 (fr) Régulation de courants de phases d'un onduleur
EP2639955A2 (fr) Procédé de réglage d'un convertisseur de courant à commutation automatique
EP4120500A1 (fr) Procédé de régulation de la taille du réseau électrique dans un réseau d'alimentation
DE102022119897A1 (de) Spannungsstellender wechselrichter und energieerzeugungsanlage
DE2421126A1 (de) Schaltungseinrichtung zur gegenseitigen wirk- und blindleistungssteuerung mehrerer parallelbetriebener wechselrichter