DE102009012488A1 - Method for energy demand determination, method for component selection and data carrier - Google Patents

Abstract

In a method for the automated determination of the electrical energy requirement of a drive system, the drive system comprises an electric motor (20), a converter (10) for driving the electric motor (20), a component (40) to be driven, and a transmission (30) connected between the electric motor (20) and the driven component (40) is looped, wherein the component to be driven (40) performs a predetermined kinematic profile. A loss model (20a) for the electric motor (20), a loss model (10a) for the converter (10) and a loss model (30a) for the transmission (30) are determined, the respective loss models (10a, 20a, 30a) being determined. consider various operating conditions that are due to the given kinematic profile, and the electrical energy requirement of the drive system is determined during a predetermined period of time using the loss models (10a, 20a, 30a) and the given kinematic profile.

Description

Technological background

The The invention relates to a method for automated determination the electrical energy demand of a propulsion system, a procedure for selecting components of a drive system and a data carrier.

at the planning and dimensioning of electric drive systems Different boundary conditions have to be considered. For example are an electric motor, an inverter and a gearbox that is usually form a drive train of the drive system, to select such that these satisfy the electromechanical dimensioning requirements, the among other things, a kinematic profile of a driven Depend on component.

increasing Energy costs, climate change and legal requirements require increasingly, that in sizing the drive system as well whose energy requirements are considered as a further dimensioning criterion becomes.

Task and solution

Of the The invention is therefore based on the object, a method for automated Determination of the electrical energy requirement of a drive system to disposal to make that a reliable one Determining the electrical energy requirement of the drive system allows a method for selecting components of a drive system to disposal to put that in the selection of the specific electrical energy needs considered, as well as a data carrier to disposal which includes programs suitable for carrying out the procedures are.

preferred embodiments are the subject of the subclaims, hereby incorporated by reference into the subject of the application to avoid repetition.

at the method according to the invention for the automated determination of the electrical energy requirement of a Drive system, the drive system includes an electric motor, for example a synchronous motor or an asynchronous motor, a converter or Frequency converter for controlling the electric motor, wherein the inverter or frequency converter from an alternating current or three-phase current with certain frequency variable in amplitude and frequency or converted voltage generated, which is applied to the electric motor is a component to be driven and a transmission that between the electric motor and the component to be driven looped is. It is understood that the drive system other components may include, for example, regenerative power supply modules operating in generator mode of the engine can feed energy back into the grid, and / or so-called Brake chopper. A drive task underlying the drive system, For example, a Förderanwen training with a wheel drive, with the objects to be transported with predetermined maximum weight first accelerated, then moved at a constant speed and then again be decelerated, gives a kinematic profile of the driven or driven component before. For the determination of the electrical Energy demand becomes a loss model for the electric motor, a loss model for the Inverter and a loss model intended for the transmission, where the respective loss models take into account different operating states, which adjust due to the given kinematic profile. In other words, the loss models are not just for one constant operating point, but take into account all operating points or operating states, which can occur in the concrete drive task. Finally will the electrical energy requirement of the drive system during a predetermined period of time, for example during a drive cycle and / or during the configured operating time of the drive system, using the loss models and the given kinematic profile. The inventive method allows a reliable one Determination of the electrical energy requirement of the drive system under consideration the underlying drive task or the given kinematic Profils, since not only stationary Operating points of the components of the drive system but dynamic, d. H. actually occurring, operating points of the components of the drive system be taken into account when determining the energy requirement. Next exists the possibility, the specific energy requirement as the so-called energy pass of the drive system on the example, energy demand shares of components of the drive system are listed separately.

In a development to determine the loss model for the electric motor, the self-supporting unit of the electric motor, winding losses in the stator of the electric motor, iron losses and / or friction losses be taken into account. It is understood that in addition to the sizes mentioned, other variables can be included in the loss model.

In In a further development, the electric motor is an asynchronous motor, wherein for determining the loss model for the electric motor rotor winding losses considered become.

In Further training is used to determine the loss model for the inverter current-dependent losses, constant losses, fan losses and / or capacitor losses taken into account. It is understood that in addition to the sizes mentioned, other sizes in the Incorporate loss model can.

In a training to determine the loss model for the transmission an inertia of the Transmission, power-dependent Losses, speed-dependent Losses and / or friction losses taken into account. It goes without saying that in addition to the sizes mentioned above more sizes in the Loss model can be incorporated.

In In a further development, the kinematic profile comprises a travel path the component to be driven, d. H. their change of location, a speed the component to be driven and / or an acceleration of the driven Component.

In In a further development, the component to be driven is a conveyor belt, a continuous conveyor, a spindle drive and / or a hoist.

at the method according to the invention for, in particular automated, selection of components of a Drive system, the drive system includes the following components: an electric motor, a converter for controlling the electric motor, a driven component and a transmission that between the Electric motor and the component to be driven is looped, wherein the component to be driven a predetermined kinematic Profile. The electric motor, the inverter and the gearbox are made of one given quantity of electric motors, converters and gearboxes such, in particular automated, selected that one of the kinematic Profile dependent Sizing rule met is. The specified quantity of electric motors, converters and gearboxes For example, it can be stored in a database that is part of an expert system for drive system design. Such an expert system For drive system design, for example, the system Drive-Solution-Designer (DSD) of Lenze AG, in this case with regard to component selection considering of sizing rules, so on a comprehensive description of component selection under consideration can be dispensed with dimensioning. For determination the electrical energy requirement of the drive system is the method of the invention for the automated determination of the electrical energy requirement under consideration of the selected Electric motor, of the selected Inverter and the selected one Geared, which for a drive system variant that meets the dimensioning requirements enough, automatically the energy demand is determined or calculated. This allows the rating of the selected Drive system variant also in terms of their energy needs or their energy efficiency.

In a further training includes the sizing one Rated power of the electric motor, a rated torque of the electric motor, one over the transmission transmissible Torque, one over the transmission is transferable Performance, thermal boundary conditions, compatibility properties components and / or rated power of the drive. It understands that the sizing rule includes more sizes can.

In a further development, the method comprises the steps of: selecting, in particular automatically selecting, a first drive system variant comprising an electric motor, an inverter and a transmission from the predefined set of electric motors, converters and transmissions such that the dimensioning rule is met, selecting, in particular automated selection at least one second drive system variant comprising an electric motor, a converter and a transmission from the predetermined set of electric motors, converters and transmissions such that the dimensioning rule is also met, wherein at least one component of the second drive system variant differs from a corresponding component of the first drive system variant, automated determination of the electrical energy requirement for the first drive system variant and the second drive system variant and selecting a drive system variant from the first and the second drive system variant depending on the energy requirements of the first and the second drive system variant. The drive system is preferred Temvariante selected, which has the lowest energy consumption.

In In a further development, the drive system variant of the first and the second drive system variant depending on the energy requirement and the cost of the drive system variants selected. in this connection can be a weighting between the decision criterion energy demand and the decision criterion costs.

Of the Inventive disk stores a program that, when executed, is a method as described above executed.

Brief description of the drawings

advantageous embodiments The invention are shown schematically in the drawings and will be described below. Hereby shows:

1 a drive system whose electrical energy requirement is determined according to the invention,

2 a modeling with loss models of components of in 1 shown drive system

3 a transmission for illustrating the determination of a transmission loss model,

4 a schematic representation of an electric motor for illustrating the determination of an electric motor loss model and

5 a schematic representation of an inverter for illustrating the determination of a converter loss model.

Detailed description the drawings

1 shows a drive system whose electrical energy requirement is determined according to the invention. The drive system includes a conventional inverter or frequency converter 10 powered by a three-phase network, a conventional electric motor 20 , For example, a synchronous or asynchronous motor, a conventional transmission 30 and a component to be driven 40 , for example in the form of a wheel drive. The gear 30 is between the electric motor 20 and the component to be driven 40 looped. It is understood that further, not shown drive components may be present, if they are required for the specific drive task.

The component to be driven 40 executes a given kinematic profile. The movement profile or the kinematic profile comprises or defines a travel path of the component to be driven 40 , a speed of the component to be driven 40 and an acceleration of the component to be driven 40 , In a conveying application with a wheel drive in which objects to be transported are initially accelerated with a predetermined maximum weight, then moved at a constant speed and then decelerated again, the result is, for example, a time-trapezoidal profile of the speed. From this kinematic profile is an electromechanical dimensioning rule for the components 10 . 20 and 30 derived from the drive system. The dimensioning rule may include, for example, a nominal power of the electric motor, a nominal torque of the electric motor, a torque transmittable via the transmission, a power transferable via the transmission, thermal boundary conditions, compatibility properties of the components and / or a rated power of the converter. For further details on drive system design based on kinematic profiles, please refer to the Drive Solution Designer (DSD) from Lenze AG.

to automated determination of the electrical energy requirement of the drive system become a loss model for the electric motor, a loss model for the inverter and a loss model for the Gear determines, with the respective loss models different operating conditions consider, which adjust due to the given kinematic profile.

2 shows a modeling with a loss model 10a of the inverter 10, a loss model 20a of the electric motor 20 and a loss model 30a of the transmission 30 , The loss models have the in 2 are input parameters represented at their inputs and are parameterized by means of parameters Par1 to Par3 bar, ie concrete types of components 10 to 30 customizable by means of suitable parameter setting. As in 2 shown, includes the inverter 10 a rectifier 11 and an inverter 12 , The loss models 10a . 20a and 30a are determined or determined as follows.

Drive system application considers friction components, acceleration components, constant loads and efficiencies. In the transmission 30 the inertia, power-dependent losses and speed-dependent losses are taken into account. With the electric motor 20 the self-inertia, stator winding losses (load-dependent heating), rotor winding losses (only for asynchronous machines including load-dependent heating), iron losses and friction losses are taken into account. At the inverter 10 Current-dependent losses, constant losses, fan losses and capacitor losses are taken into account.

In the drive system application, the temperature dependence of the friction can be additionally included. In the transmission 30 In addition, a viscosity of the oil, the temperature dependence of the losses, the gear type depending on different loss characteristics and dynamic loss components of the oil circuit can be taken into account. With the electric motor 20 In addition, switching frequency-dependent losses, harmonic losses, individually different operating temperatures, temperature differences stator-rotor, temperature-dependent properties of the permanent magnets, a current model for operation in the field weakening range and the influence of internal fans can be taken into account. With the frequency converter 10 Depending on the switching frequency, the dependence on the type of modulation, the separation to rectifier and inverter losses and energy-saving modes or a stand-by operation can be considered.

Further may be an optional supply or regenerative module into the loss models or an energy consideration. Berücksicht can be also an optional brake chopper, losses in one Braking resistor and losses on motor cables and filters.

For the drive system task the required power is calculated from the constant, the variable and the dynamic parts. For this purpose, the torque of the application M _App (t) and the angular velocity ω _App (t) are determined from the kinematic boundary conditions and from this the power is determined: P app [kW] = M app · ω app · 10 -3 (1)

The power required to accelerate the inertia is calculated as: P dyn, App [kW] = J app · α app · K app · 10 -3 (2)

The energy demand of the application at time t within the cycle thus results in:

Of the Energy demand of the entire cycle is through the integral over the entire cycle time T formed.

The energy stored in the inertia is:

For an optional additional drive element, the maximum torque of the application must first be determined, since this is decisive for the constant proportion of the losses. M max, app = Max (m app (t)) (5)

Furthermore, the constant friction torque of the drive element M _{μ, K is} used for the calculation. From the torque curve of the application, the drive torque for the additional drive element is calculated:

The power loss of the drive element is thus calculated as:

The energies stored in the inertia of the drive element are calculated with the acceleration power P dyne, K [kW] = J K · α app · ω app · 10 -3 (8th) to:

Of the Energy demand of the entire cycle is through the integral over the entire cycle time T formed.

The total power at the drive shaft of the drive element is calculated to: P sum, In, K = P app + P th, K + P dyne, K (10)

• • Leistungsabhängige Verluste P_th,N,G(M_in,G; n = const)
• • Drehzahlabhängige Verluste P_th,N,G(M_i = const; n_in,G)
• • Gesamtleistung am Getriebeeingang P_sum,in,G
• • Abgegebene Leistung P_sum,in,K

The following is the determination of the transmission loss model with reference to 3 derived. The following losses / sizes are considered:

• • Power-dependent losses P _{th, N, G} (M _{in, G} ; n = const)
• • Speed-dependent losses P _{th, N, G} (M _i = const; n _{in, G} )
• • Total power at the transmission input P _{sum, in, G}
• • Delivered power P _{sum, in, K}

From the data for the load variables at the gearbox output of the gearbox, the input variables with regard to speed and torque are to be determined. n in, M = 6 6 0 0 2 × π · i K · i G · ω app (11)

To calculate the transmission losses, the losses in the design point are first determined. (M _{N, G n, N, G} = 1400 min ^-1) per stage defines the efficiency of the transmission in point. The rated efficiency results for an n-stage gearbox: η N, G = η n i with η i = Efficiency per level

The power loss at the design point can then be determined as:

For the transmission losses 40% of the losses are calculated in proportion to the transferred power (tooth friction losses) and 60% as speed-dependent Splash losses assumed.

The acceleration power for the transmission components is calculated as: P dyn, G [kW] = (J G + J Cpl ) * 10 -4 · α M · 2 × π 60 · n M · 10 -3 (15)

The energy requirement of the transmission thus results in:

The energy requirement of the entire cycle is formed by the integral over the entire cycle time T. For the transmission input now the total power can be determined. P sum, in, G = P app + P sum, In, K + P dyn, G (17)

• • Wicklungen (Stator) P_R,N,S
• • und bei ASM (Rotor) P_R,N,R
• • Eisenkreise P_Fe,N
• • Reibung P_μ,N,M
• • Zusatzverluste P_add,N,M

The following is the determination of the engine loss model with reference to 4 derived. The following losses / sizes are considered:

• • Windings (stator) P _{R, N, S}
• • and at ASM (rotor) P _{R, N, R}
• Iron circles P _{Fe, N}
• • friction P _{μ, N, M}
• • Additional losses P _{add, N, M}

For the losses of the motor, the losses must first be divided according to their causes in the rated operation. For standard asynchronous machines, a winding overtemperature of Δθ _{max, M} = 80 K, for servomotors of Δθ _{max, M} = 105 K is used.

The pole pair number of the machine is determined from the rotating field frequency and the speed:

The synchronous speed can thus be calculated to:

This results in the slip to:

For the calculation of the stator winding losses, the winding resistance is needed. This is determined from the strand resistance at 20 ° C: R N, S = R 0, S · (1 + α CU · [Δθ max, M + 20]) (21)

For the warm machine, the winding resistance is extrapolated with the load:

The total losses of the machine in rated operation can be determined from the difference between the electrical power consumed and the mechanical power output. P in, N, M [kW] = P in, N, M - P N, M = {√3 · U N, M · I N, M · cos N - 2 × π 60 · M N, M · n N, M } * 10 -3 (23)

The winding losses in the rated mode can thus be determined for the star-connected machine: P R, N, S [kW] = 3 · R N, S · I 2 N, M · 10 -3 (24a)

For the machine connected in delta, the following applies: P R, N, S [kW] = R N, S · I 2 N, M · 10 -3 (24b)

First, the additional losses are determined, these are assumed to be 0.5% of the electrical power absorbed. P add, N, M [kW] = 0.005 · √3 · U N, M · I N, M · cos N · 10 -3 (25)

For further calculation, the difference between the total losses and the stator, rotor winding and additional losses is assumed to be 90% in the iron losses and 10% in the friction losses. The friction losses are to be added for the division of the air gap power P _{δ of} the mechanical power.

The Rotor losses can then be over Determine the law for splitting the air gap performance. she are set to zero in synchronous machines.

For the iron losses in rated operation, this results in: P Fe, N = 0.9 · {P in, N, M - P R, N, S - P R, N, R - P add, N, M } (27)

The friction losses are then determined by: P μ, N, M = 0.1 · {P in, N, M - P R, N, S - P R, N, R - P add, N, M } (28)

Furthermore, the load variables are determined during operation of the machine. First, the internal torque profile of the machine is determined: M inr, M = M in, G + [J M + J aux, M + J B ] X 10 -4 · α M (29)

Does that fall? mechanical brake at a standstill, so the torque is too Zero set.

For the calculation The loss of iron requires the course of the rotating field frequency.

The difference between the synchronous speed and the output speed of the motor is assumed to be proportional to the load torque:

For the investigation the current heat losses the motor current is needed. This is calculated using a simplified model, where the Model for the synchronous machine only for the basic setting range is suitable.

The motor current is split into two components, the current in the longitudinal axis and the current in the transverse axis. For the synchronous machine, the current in the longitudinal axis is set to zero. The current in the longitudinal axis is calculated for the asynchronous machine in the basic setting range to: I dm = I N, M · sinφ N (31) and in the field weakening area:

The cross-flow is load-dependent in the basic setting range and is calculated as:

Neglecting the flux linkage in the transverse axis, the transverse current is calculated for the field weakening range as follows:

For the rotating field frequency of the asynchronous machine also results in a load dependence:

For the field weakening range, the frequency is calculated as:

Out the longitudinal component and the transverse component of the current can then be calculated as the total current.

In the phases of the controller inhibit, the motor current is set to zero. With these precalculations can now the engine losses are determined.

Statorwicklungsverluste:

Friction losses:

Pdyn,M = (JM + Jaux,M + JB)·10–4·αM·2·π60 ·nM (38) For the calculation of the rotor losses the slip and the acceleration power of the engine are required according to the law of the division of the air gap power:

P dyn, M = (J M + J aux, M + J B ) * 10 -4 · α M · 2 × π 60 · n M (38)

The Winding losses in the rotor then result from the following equation, This is due to an identical with the stator resistance increase the temperature went out.

In case the formula is no longer computable, the following approximation is made:

The iron losses are determined in the base range to:

da dann das Feld linear mit der Frequenz abnimmt.In the field weakening range, the iron losses are calculated with

because then the field decreases linearly with the frequency.

The Additional losses are assumed to be 0.5% of the electrical power transmitted.

From the partial services, the total power loss for the engine is calculated. P th, M = P R, S + P R, R + P Fe, M + P add, M + P μ, M (42)

With The power loss can then be reduced by the energy demand of the Motors are calculated.

Of the Energy demand of the entire cycle is through the integral over the entire cycle time T formed.

The power at the engine then results from the sum of the services: P sum, in, M = P sum, in, G + P dyn, M + P th, M (44)

• • Verluste auf einer Masterplatine MP P_0,th,I
• • Stromabhängige Verluste im GR,WR P_I,th,I
• • Ohmsche Verluste einer Leistungsplatine LP und der Kondensatoren P_R,th,I

The following is the determination of the inverter loss model with reference to 5 derived. The following losses / sizes are considered:

• • losses on a master board MP P _{0, th, I}
• • Current-dependent losses in GR, WR P _{I, th, I}
• Ohmic losses of a power board LP and the capacitors P _{R, th, I}

The Inverter losses are divided into losses in supply the control electronics, in losses in the rectifier, losses in the capacitors, losses in the power board and losses in the inverter.

The loss model is based on the calculation of the losses via the current-dependent heat sink losses P _{I, th, I} ,, the losses in controller inhibit P _{0, th, I} and the total losses P _{th, N, I.} If no loss data are available, the losses in the rated operation are determined according to the following equation:

If the heat sink losses are given, but not the total losses, then: P th, N, I [kW] = {p I th, I + P 0 th, I } * 10 -3 (45b)

are no losses with indicated with controller lock, so becomes a constant Loss of 0.010 kW assumed.

If the total losses as well as the heatsink losses as well as the losses are shown with controller inhibit, the remaining losses are assumed to be in 30% constant losses for the fan operation and 70% losses for the capacitors and conductor tracks proportional to I ² . P th, Vlt, I [kW] = 0.3 · {P th, N, I - P I th, I (I N, I ) - P 0 th, I } * 10 -3 (46)

The Losses in eq. 46 are set to zero at controller inhibit.

For the load-dependent losses then follows:

The total losses then result from the sum: P th, I = P I th, I + P R th, I + P 0 th, I + P th, Vlt, I (49)

From this, the total power at the inverter input can be determined to: P sup, I = P sum, in, M + P th, I (50)

The self-consumption of the inverter results from:

Of the Energy demand of the entire cycle is through the integral over the entire cycle time T formed.

From the power P _{sup, I} can be determined by the positive portion of the power absorbed energy for a cycle and for the negative portion of the energy recoverable.

Out the period of observation in years, the number of operating weeks in Year, the number of operating days per week and operating hours per day calculate the number of cycles with the cycle time.

By a freely selectable energy price and with a predetermined 550g / kWh CO ₂ equivalent energy costs and the CO ₂ content can be determined conclusively. K sum, E = K εE · e x (55) m sum, CO2 [kg] = 0.55 · E x (56)

The described determination of the loss models allows a reliable determination of the electrical energy demand of the drive system in interest Time intervals. this makes possible the optimization of a drive system with a view to efficient Energy utilization.

there become the concrete drive task as well as the drive components Engine, gearbox, inverter and possibly other mechanical Components, such as brake, clutch, transmission elements, etc., and electrical components, such as brake choppers, braking resistors, power and regenerative modules, etc., taken into account.

The determination or calculation of the energy requirement takes place here not only with regard to a single component of the drive system at a constant operating point. According to the invention, the entire drive system is evaluated in the operating range occurring during the drive task taking into account the individual requirements of the application (machine). Appendix: List of formula symbols with units transmission engine inverter M _{N, G} [Nm] _{nN, M} [min ^-1 ] P _{th, N, I} [W] n _{in, N, G} [min ^-1 ] P _{N, M} [kW] P _{I, th, I} (I _{N, I} ) [W] J _G [kgcm ² ] R _{0, S} [ohm] P _{0, th, I} [W] J _Cpl [kgcm ² ] U _{N, M} [V] I _{N, M} [A] M _{N, M} [Nm] J _M [kgcm ² ] J _B [kgcm ² ] f _{N, M} [Hz]

Claims (13)

Method for automatically determining the electrical energy requirement of a drive system, the drive system comprising: - an electric motor ( 20 ), - an inverter ( 10 ) for controlling the electric motor ( 20 ), - a component to be driven ( 40 ) and - a transmission ( 30 ), which between the electric motor ( 20 ) and the component to be driven ( 40 ), wherein - the component to be driven ( 40 ) performs a predetermined kinematic profile, characterized in that - a loss model ( 20a ) for the electric motor ( 20 ), a loss model ( 10a ) for the inverter ( 10 ) and a loss model ( 30a ) for the transmission ( 30 ), whereby the respective loss models ( 10a . 20a . 30a ) take into account different operating conditions, which are due to the given kinematic profile, and - the electrical energy requirement of the drive system during a predetermined period of time using the loss models ( 10a . 20a . 30a ) and the predetermined kinematic profile is determined. A method according to claim 1, characterized in that for determining the loss model for the Electric motor, the self-inertia of the electric motor, winding losses in the stator of the electric motor, iron losses and / or friction losses are taken into account. Method according to claim 1 or 2, characterized that the electric motor is an asynchronous motor, wherein for determining the Loss model for the electric motor rotor winding losses are taken into account. Method according to one of the preceding claims, characterized characterized in that for determining the loss model for the inverter inverse Losses, constant losses, fan losses and / or capacitor losses taken into account become. Method according to one of the preceding claims, characterized characterized in that for determining the loss model for the transmission a self-indulgence of the gearbox, power-dependent Losses, speed-dependent Losses and / or friction losses are taken into account. Method according to one of the preceding claims, characterized characterized in that the kinematic profile a travel of the component to be driven, a speed of the component to be driven and / or an acceleration of the component to be driven. Method according to one of the preceding claims, characterized characterized in that the component to be driven comprises a conveyor belt, a continuous conveyor and / or a hoist is. Method for selecting components of a drive system, the drive system comprising the following components: - an electric motor ( 20 ), - an inverter ( 10 ) for controlling the electric motor ( 20 ), - a component to be driven ( 40 ) and - a transmission ( 30 ), which between the electric motor ( 20 ) and the component to be driven ( 40 ), wherein - the component to be driven ( 40 ) performs a predetermined kinematic profile, the method comprising the steps of: - selecting the electric motor ( 20 ), Selecting the inverter ( 10 ) and selecting the gearbox ( 30 ) from a predetermined amount of electric motors, converters and gears such that a dependent on the kinematic profile dimensioning is met, characterized in that - for the automated determination of the electrical energy requirement of the drive system, the method according to one of claims 1 to 7, taking into account the selected Electric motor ( 20 ), of the selected inverter ( 10 ) and the selected transmission ( 30 ) is carried out. Method according to claim 8, characterized in that that the dimensioning rule is a rated power of the electric motor, a rated torque of the electric motor, a transferable via the transmission Torque, one over the transmission is transferable Performance, thermal boundary conditions, compatibility properties includes the components and / or a rated power of the inverter. A method according to claim 8 or 9, characterized through the steps: - Select one first drive system variant comprising an electric motor, a Inverter and a gearbox from the given set of electric motors, Converters and gearboxes such that the sizing rule Fulfills is - Select at least a second drive system variant comprising an electric motor, a converter and a gearbox from the given quantity of Electric motors, converters and gears such that the dimensioning also fulfilled is - automated Determination of the electrical energy requirement for the first drive system variant and the second drive system variant and - Selecting a drive system variant from the first and the second drive system variant depending of their energy needs. Method according to claim 10, characterized in that that the drive system variant is selected, the least Energy requirement has. A method according to claim 10, characterized in that the drive system variant of the ers th and the second drive system variant depending on the energy requirements and the cost of the drive system variants is selected. disk with a program stored on it, whereby when executing the Program from the disk a method according to any one of claims 1 to 12 is carried out.