Siemens Aktiengesellschaft

Leonhard Reng

Felix Blaschke

Gerhard Trauth

A rail vehicle may be provided with a plurality of individual wheels (11, 12, 21, 22) and traction motors which are supplied with power on a wheel block by wheel block basis by means two control devices each including open loop and closed loop controls (6, 8). The wheel speeds (n11, n12, n21, n22) are used to determine two wheel block speeds (n1, n2), from which an actual speed difference value (.DELTA.n) is calculated. A manipulated variable (.DELTA.m*) is produced from a comparison of the actual speed differences value (.DELTA.n) to a set speed difference value (.DELTA.n*). A set traction lever value (m,) is increased and reduced by this manipulated variable (.DELTA.m). Consequently, the wheel blocks (1, 2) obtain a definitively set speed difference corresponding to the arc radius (r), whereby the running behavior on bends is significantly improved by virtue of the satisfied rolling condition.

Method and apparatus for improving the running characteristics of a

In a method and a device for eliminating an inclination of a wheel-block bogie of a rail vehicle having a plurality of individual wheels, the determined wheel speeds of the wheel-block bogie may be added in a crosswise manner. Sum speeds formed in this manner are combined to form an actual sum-difference speed which represents the actual inclination of the bogie, and this actual inclination is brought to a predeterminable desired inclination. In this way, an inclination of the wheel-block bogie is recognized and corrected without additional sensors, regardless of how it has been caused. As a result, optimum travel behavior is obtained in straight ahead travel and also on curves.

Method and apparatus for eliminating an inclination of a wheel-block

A method for the formation of the actual load angle value for a field-oriented regulated rotary field machine and apparatus for field-oriented regulation of the machine. In order to impress in a voltage-impressing converter the load angle, i.e. the angle between field axis and stator current vector, an angle regulator is used to which a given nominal load angle value (wif*) is supplied. In order to form from the stator-oriented acutal current angle (wis) tapped off at the machine via a current detector (I-DET) the actual load angle value associated the nominal load angle value with wif*, by a decoupling computing unit (CAL) from the given components of the field-oriented nominal current vector, the field-oriented angle (wuf*) of the associated field-oriented nominal voltage vector is calculated and subtracted from the stator-oriented angle (wus) of the actual voltage vector. The actual load angle value (wif) is then given by wis-wus+wuf*. The output signal of the angle regulator (W-REG) and the decoupling computing unit (CAL) form the input quantities of the trigger unit for a voltage-impressing converter (PWR) feeding the machine at which the stator-oriented voltage angle (wus) can be tapped off.

Method for the formation of the actual load angle value for a

In order to feed to the converter on the load side of an intermediate-link frequency converter a frequency control signal (fI(S)*) which is formed by means of an angle controller (RW) from the difference of an angle reference value (wi(F)*) and a corresponding actual value (wI(F)), an actual value of the phase current is required which, for stable operation, must not contain heavy harmonics in stable operation nor must not be damped excessively dynamically by smoothing. Therefore, the measured actual angle value (wI(S)) is fed as the reference value of a servo controller (RS), to the output of which the integral (wI(S)*) of the frequency control quantity is added and the output of which is fed back to the input of the servo controller (RS).

Apparatus for controlling the load angle of a converter

In the field-oriented control of an asynchronous machine, the flux angle of which is calculated by a flux computer from the current and the voltage as the integral of the EMF, the correct flux vector must be available already at the start-up of the machine. For this purpose, one axis (M.phi.1) of a model coordinate system as well as the components (iO*, iM*=0), referred to the model coordinate system, of a vector parallel to this axis is determined at an input device (E1, E2) by a constant, given starting angle (.phi.MO*). This vector is transformed by means of the field angle (.phi.s) calculated by the flux computer for forming the converter control variables into the stator coordinate system while the machine is excited but standing still. The angle deviation (.phi.MO*-.phi.s) of the calculated field angle from the starting angle is used by a controller (CR) for correcting the calculated field angle. Before the setting device switches to the operationally provided reference value transmitter (RV), the calculated filed angle (.phi.s) therefore assumes the starting angle (.phi.MO*) and the control device forces via the converter a stator current and machine flux parallel thereto. At the same time, also the parameter of the stator resistance used for calculating the flux can be adjusted.

Method and apparatus for operating a field-oriented rotating-field

A device for determining a load operating parameter signal, such as the flux of a rotary field machine, has an integrating circuit added at the input of the instrument transformer with a transfer function k/(1+s.multidot.k/.omega..sub.N) that amplifies reduced low frequency load voltage inputs to the transformer to avoid calculation inaccuracies due to the transformer transfer error. Circuitry having the inverse transfer function located at the output of the transformer compensates for the amplification distortion.

Device for determining a parameter signal for a voltage-fed load

An apparatus for determining the common frequency w of two independently variable a-c quantities is described. In a rotating-field machine, the flux, for instance, is described by two electrical a-c quantities which together determine the magnitude and direction of the field. The two a-c quantities are variable independently of each other and the instantaneous direction of the field is given by an angle.alpha. according to the relation a.sub.1 /a.sub.2 =cotan.alpha., where a.sub.1 and a.sub.2 are the two a-c quantities. In order to determine the frequency of rotation w=d.alpha./dt of the field from these quantities, the quantities a.sub.1 and a.sub.2 are each fed to smoothing stages and thence to a computing circuit, wherein the quotient (d.sub.1 .multidot.a.sub.2 -d.sub.2 .multidot.a.sub.1)/(d.sub.1 .multidot.a.sub.1 +d.sub.2 .multidot.a.sub.2) proportional to the frequency is formed from a.sub.1 and a.sub.2 and the smoothed quantities d.sub.1 and d.sub.2. The use of differentiators is thereby avoided, which would cause a phase error as well as difficulties when harmonics of the quantities a.sub.1 and a.sub.2 are present.

Apparatus for determining the common frequency of two independently

Apparatus is disclosed wherein parameter values for the stator resistance, the main inductance and the stray inductance of an asynchronous machine is detected without using information about the rotor position. Thereby the apparatus consists of an EMF-forming circuit, an arithmetic control circuit, an arithmetic model circuit, and a control circuit. All circuits are coupled to form an overall model circuit designed according to a closed loop circuit to simulate the operational conditions of an asynchronous machine. In a balanced position of the control circuit the output signals of the control circuit represent the actual parameter values to be determined.

Device for determining the parameter values for stator resistance,

A control unit for regulating an asynchronous motor supplied with power from a three phase network by a line-controlled power converter which is DC coupled to a self-commutated inverter has a function generator and a current regulator which controls the stator current of the motor by the controlling rectifier valves in the inverter. Control of the stator current is a function of a predeterminable value of flux fed into the function generator. In a parallel control system, an actual-value computer and a load state control regulate the stator frequency by generating a signal for controlling the self-commutating converter as a function of the actual values of the stator current, the stator voltage, and a value calculated from the function generator input variable. The computer forms signals corresponding to the amplitude of the flux vector, and to a stator current component perpendicular to the flux vector. A variable derived from the predeterminable variable is applied to the load state control as a reference value. Fall-out-proof, low oscillation, speed control is effected from low angles to nearly 90.degree..

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Erlangen, Germany

Leonhard Reng