JPS58123388A - Drive system speed control device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides speed control of a drive system having a speed control loop and a torque control minor loop (current control loop), wherein the predictive control signal of the torque control loop is derived from a ramp function generator. It is related to the device.

This type of device is used, for example, in the field of elevator and hoist drive systems that are supplied with power from power converters.
It is known from the s-tem catalog AE 319/1126.

The operating characteristics of the speed control loop in an electrical drive system can be significantly improved by predictive control of the current control loop.

The current or torque used for accelerating the rotating mass depends just on the field present (field weakening range) and on the magnitude and direction of the load torque.

If the controlled drive train is loaded in the control direction with 50% of the maximum torque, the drive train will only load 50% of the maximum torque in the rated field for acceleration and 150% of the maximum torque in the case of deceleration. has as a torque increase. This situation must be taken into account in the case of constant control in order to be as time-optimal as possible. A similar concept applies to the control of internal combustion engines. 1. An object of the present invention is to derive a predictive control signal so that control is optimal in terms of time.

This object is achieved according to the invention in that the predictive control signal is limited according to a predetermined torque setpoint value from the speed control loop. In that case, the output of the predictive control unit is advantageously a known nonlinear ramp function generator, which consists of a sign function generator for generating the predictive control signal and a downstream integrator. . The limit of the sign function must correspond to the reserve torque (preliminary current) used for acceleration or deceleration. According to the invention, it is therefore calculated from the torque setpoint value (current setpoint value) required by the regulator itself. The output of the sign function provides the required accelerating or decelerating current in the case of electric machines. The speed ramp that should be expected in the output of the ramp function generator is determined by a value proportional to the magnetic flux of the electric machine and the rotating mass. Control deviation 1:: on speed regulator.

In order to avoid this, the speed setpoint value is advantageously also delayed by simulating the current control loop and the speed smoother.

The idea of the invention described above can also be used in the field of test stands for a plurality of drive systems that are elastically coupled to each other, for example electric motors and transmissions. In that case, the torque regulator is derived from a common speed regulator.

The predictive control signals of both torque control loops are determined according to the reserve torque of the lowest output drive system.

Next, the present invention will be explained in more detail with reference to the drawings.

As shown by the chain line in FIG. 1, the entire apparatus can be divided into a predictive control section 1 and a main control section 2 having a control loop.

The main control unit 2 with a control loop includes a speed regulator 3,
This speed regulator 3 is the current regulator 4 in the minor loop.
A reference input amount J is supplied for This current regulator 4
The output signal of controls the armature voltage of the DC motor 7 with the load of the machine 71 via the control unit 5 and the sirisk regulator 6. Here, the total moment of inertia is Tθ
It is shown in The motor torque is related to the magnetic flux Φ of the field 73 and the armature current J.

A speedometer generator 72 is connected to the DC motor 7 , and this speedometer generator 72 supplies an actual speed value Ω to the speed regulator 3 via a smoothing circuit 31 .

A ramp function generator 9 is arranged upstream of the speed regulator 3 . This ramp function generator 9 changes the reference input amount Ω1 of the speed regulator 3 according to a predetermined time function when the speed target value Ω7 at the input end changes. In order to achieve as optimal a control as possible in time, a predictive control signal is additionally input from the ramp function generator 9 via a line 10 to the current regulator 4 . This predictive control signal is controlled, for example, by the output signals B+, B- of an analog computer 8 via a limiting section in the ramp function generator. A value 4 proportional to a predetermined torque (current) is inputted to the calculator 8 via a conductor 11 in order to detect the limit amount.

Next, the operation will be explained with reference to FIG. First, resting state l
? ) to depart. In this case, the speed control amount Ω8 outputted from the output end of the ramp function generator 9 corresponds to the input target value width. For example, if it is assumed that the input setpoint value ~ is suddenly increased, a deviation between the setpoint value and the actual value appears at the input of this nonlinear ramp function generator 9, and via this deviation, A code function generator 91 with a limiting characteristic having a finite slope is controlled. The limit values B, B of this code function generator 91 are given by the output signals B, B of the computer 8. The output signal of the sign function generator 91 is multiplied by a value 2Φ proportional to the magnetic flux Φ in a multiplier 92. Here coefficient 2
was introduced to set a limit value of, for example, 10 volts. It can also be realized at the input of the integrator. It reaches an integrator 93 matched to the moment of inertia Tθ of the drive train. As a result, the reference input signal Ω8 at the output of the ramp function generator 9 rises according to a predetermined rate and ramp. By negative feedback to the input terminal, the pre-given []
When the target value Ω7 is reached, the input value of the sign function becomes zero,
The starting process can thus be brought to an end. In order to prevent control deviation from occurring in the speed regulator 3,
The speed target value is delayed by time simulators 94 and 95 with time constants T and TgQJ of the current control loop and speed smoother. A predictive control signal is taken out from the output end of the code function generator 91 via the conductor 10, multiplied by a coefficient 2, and then
In addition to the output signal JR of the speed regulator 3, it is input to the current control loop 4 via the limiting circuit 41 as a predicted control amount. Limiting circuit 41 limits the current value to values B and B-. The current control J J control loop determines the armature voltage of the DC motor 7.

The limit values B, B of the sign function generator 91 corresponding to the acceleration or deceleration of the available reserve current are calculated by the calculator 8 from the current target value J supplied from the speed regulator 3, and are limited to the sign function generator 91. given as a value. In this case, the following equation is used as the calculation principle.

B=0.5X(B-J) R 13'-0,5X(-B''--Jw) R Therefore, the predictive control signal on conductor 10 always corresponds to the maximum possible acceleration or deceleration current (torque). do.

In this way, accurate predictive control corresponding to ideal regulation limits can be achieved. This predictive control can be applied in exactly the same way, for example, to internal combustion engines in which a torque control loop is provided instead of a current control loop.

In the device of FIG. 3, two elastically coupled drive systems 16 and 12 are provided.

The drive train here can be, for example, an internal combustion engine, a Ward-Leonard device, or a conventional DC machine with a power converter in the armature circuit. These drive systems have gear ratios i, i
The gearboxes 13, 14 and the gears 2 and 2 are elastically coupled to each other via tail gears 15.

Such configurations occur, for example, in transmission test stands in the automobile industry.

Here, the predictive control must additionally take into account the following conditions.

a) different rated capacities of the electric motor, b) different speeds of torque control circuits, e.g. internal combustion engines, and direct current machines with armature current control; c) avoidance of shocks in the equilibrium process via elastic couplings of this type. In the drive system, the integrator of the ramp function generator 9 is determined by the drive system that can be accelerated at the lowest speed with respect to the rated capacity, field, transmission ratio and rotating mass. As will be explained below with reference to FIG. 4, by means of an additional circuit, the setpoint values of the accelerating currents are weighted in such a way that the dynamics of the regulation are symmetrical and the rotational speeds about the axis of the drive train course with a common slope. Is possible.

As can be seen from FIG. 4, in order to control the sign function generator 91, a ramp function generator 9 is additionally provided which also controls an integrator 93 by means of a calculator 8 according to the formulas described below.

The output value of the integrator 93 is determined by a simulation circuit 96, 97, which simulates the different time constants TeJ and TeJ2 of the current control loop.
Simulation circuit 9 that simulates the time constant TgQ of the smoothing circuit
8 to the speed regulator 3.

This speed regulator 3 has limit values B, BJ1 and BJ2.
' Together with BJ2, the current target values JR0 and J are supplied to the current regulators 242 and 43 of the drive systems 16 and 12, respectively. A limit value for the sign function generator 91 is calculated from the current target value applied to the calculator 8 via the conductors 111 and 112 according to the formula described below. The output signal of the sign function generator 91 is derived from the signals 1105 and 106.
to the current control loop as an additional predictive control signal.

In order to take into consideration the weighting of different drive systems and the different time characteristics, this predictive control circuit is further provided with additional simulation circuits 101, 102 (time constant T TeJl) eJ2+ and weighting circuits 103, 104. The weight is determined by the circuit 103.10', a weighting factor of 4, and 2 by the computer 8. Furthermore, multipliers 95, 107 are provided, the multipliers 995, 1.07 being limited to a pre-given 10 volt range.

can.

Arithmetic unit 8 operates according to the following equation.

B""0.5'Min[B;, -J-)/4) I-1
, Madashi, Te3. Ta2: Moment of inertia of both drive systems, 2: Maximum torque m/normalized torque φ0. Magnetic flux of φ2 two-car electric motor 16.12"ges='6
yo・i2゛Product of the gear ratios of both transmissions, ],・.

B';i'B;
=1 or 2)

[Brief explanation of the drawing]

FIG. 1 is a block diagram for explaining the principle configuration of a device showing an embodiment of the present invention, FIG. 2 is a block diagram showing the detailed configuration of the device, and FIG. 3 is a block diagram of two sets elastically connected. FIG. 4 is a block diagram showing an embodiment of a control device for the device of FIG. 3. DESCRIPTION OF SYMBOLS 1... Prediction control part, 2... Main control part, 3... Speed regulator, 4... Current regulator, 9... Ramp function generator.

Claims (1)

[Claims] 1) A speed control device for a drive system having a speed control loop and a torque control minor loop (current control loop), in which a predictive control signal of the torque control loop is derived from a ramp function generator, A speed control device for a drive system, wherein the predictive control signal is limited according to a torque target value given in advance from a speed regulator. 2. In the device according to claim 1, the ramp function generator includes a sign function generator limited depending on the torque target value and an integrator followed by the sign function generator, and the predictive control A speed control device for a drive system, characterized in that a signal can be extracted from between a sign function generator and an integrator. 3) The drive according to claim 1, characterized in that an electrical simulation circuit for a torque control loop and a speed smoothing section is provided between the ramp function generator and the speed regulator. System speed control device. 4) In the device according to claim 1, a plurality of sets of drive systems are provided to be elastically connected to each other, and the torque regulators of the drive trains are guided from a common speed regulator, and the torque control loop is connected to the drive system. A speed control device for a drive system, characterized in that a predictive control signal to be introduced is limited in relation to the torque of the drive system with the lowest output.