JPH0626992A - Reverse rotation preventing device for dynamometer - Google Patents

Abstract

PURPOSE:To ensure control of travel resistance, eliminate shocking load generation, and prevent reverse rotation. CONSTITUTION:In a dynamometer having current control systems on a torque control system using the power absorbing torque of the dynamometer as a travel resistance command value and the minor loop of the torque control system, a current control amplifier 10 has a voltage feedback circuit 14 for zeroing the amplifier output to the voltage polarity for reversely rotating an electric motor. At zero speed of the electric motor, the output of a torque control amplifier 15 is zeroed by a limiter value control circuit 16 to eliminate a hunting phenomenon in the stopped state, and the output is gradually raised from zero to a general limit value to eliminate a torque shock.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a shiyashi dynamometer and an engine dynamometer, and more particularly to a reverse rotation preventing device in running resistance control.

[0002]

2. Description of the Related Art A shiyashi dynamometer is used for testing an engine and power transmission system of an automobile and for a simulated driving test.
Input / output control is performed by using a rotating machine that becomes a DC machine or an induction machine as power absorption or drive means.

In this control, the rotating machine is switched to speed control, torque control or running resistance control according to the test purpose.

Here, the running resistance control is set as the sum of running resistance, inertial resistance, and uphill / downhill resistance of the automobile, and controls the dynamometer torque as a function of speed so as to apply a load equivalent to that on the road to the automobile or engine. To do.

FIG. 3 shows a block diagram of a running resistance control system in a coconut dynamometer. Car 1 has its drive wheels 1A
Is mounted on the roller 2, the DC machine 3 as a rotating machine is coupled to the roller 2, and the vehicle 1 side controls the speed and slot opening of the engine 1B according to the acceleration / deceleration pattern by the control device 4. On the DC machine 3 side, torque control is performed in accordance with the running resistance command from the running resistance setting device 5.

This torque control is performed by feedback control by the torque control amplifier 8 by matching the torque detection signal of the DC machine 3 by the load cell 6 and the strain amplifier 7 and the running resistance command. A current control system is provided in the minor loop of the torque control system to control the current of the DC machine 3.

That is, the output of the torque control amplifier 8 is taken out as a current-limited current command by the limiter circuit 9, and a phase control signal is sent to the current control amplifier 10 by matching this current command with the current detection signal of the DC machine 3. Then, the phase control amplifier 11 controls the firing phase of the thyristor rectifier 12 from this phase control signal to control the current of the DC machine 3.
Here, in the case where the traveling resistance control includes the uphill / downhill resistance, the uphill resistance component is subjected to load absorption control of the DC machine 3 to generate a torque in a direction opposite to the traveling direction. On the other hand, on the side of the automobile 1, when simulating a stopped state on an uphill road, the transmission is put in a neutral state, and since no mechanical brake operation control is provided, the same state as when stopped on a flat road is set.

Therefore, in the simulation of a stopped state on an uphill road, even if the vehicle speed is zero, the DC machine reverses due to the uphill resistance, and this reversal may reach a critical speed depending on the set amount of the uphill resistance.

In order to solve the above problem, conventionally, a switch circuit 13 and a voltage feedback circuit 14 are provided in the configuration shown in FIG. 3 to prevent reverse rotation.

The switch circuit 13 is provided at the output stage of the running resistance setting device 5, and the setting device 5 opens the relay contact 13a at a speed of zero to a negative voltage which causes a running resistance of the absorption torque, and a zero torque. Of the order. As a result, although the stopped state simulation includes climb resistance, the torque command of the torque control amplifier 8 becomes zero at zero speed, and the reverse rotation phenomenon is prevented.

With this switch circuit 13 alone, since the speed is not zero at the time of deceleration for stopping from the running state, the reverse rotation phenomenon of the DC machine 3 occurs due to the absorption torque and the inertial component of the climbing resistance. Therefore, the voltage feedback circuit 1 is added to the current control system.
4 is provided.

The voltage feedback circuit 14 detects only the voltage when the DC machine 3 reversely rotates by the diode 14a, and uses this voltage as a feedback signal to the current control amplifier 10, thereby making the output of the current control amplifier 10 zero. To

When the reverse resistance is prevented only by the voltage feedback circuit 14, the torque control amplifier 8 is input to the current control amplifier 10 as a reverse voltage command when the climbing resistance in the stopped state appears as a torque command. In response to the command, the voltage feedback circuit 14 causes a hunting phenomenon with a delay in its suppressing operation.

[0014]

In the conventional reverse rotation prevention device, the purpose of the reverse rotation prevention can be achieved by the switch circuit 13 and the voltage feedback circuit 14, but there are the following problems during normal operation.

(1) When shifting from the stopped state to the start control, two elements related to the operation delay of the relay contact 13a and the offset until the relay reaches the operating point become a delay command value which is entangled, and a necessary amount of It is not possible to give a running resistance load.

(2) Since the switch circuit 13 is switched on and off, a shocking traveling resistance load is generated depending on the set amount of climbing, which gives a torque shock to the automobile side and reduces the simulation performance.

It is an object of the present invention to provide a device that ensures running resistance control and eliminates shocking load generation to prevent reverse rotation.

[0018]

In order to solve the above-mentioned problems, the present invention performs torque control of an electric motor by a torque control system using a running resistance command value of an automobile to be tested as power absorption torque, and the torque control is performed. In a dynamometer that controls the current of the electric motor by providing a current control system in the minor loop of the system, a voltage feedback circuit that controls the output of the current control system to zero when the electric motor has a voltage polarity in the reverse direction, Of the output limits of the torque control amplifier of the torque control system, the current of the electric motor adjusts the limit on the power absorption side, and this adjustment gradually increases the rotation speed of the electric motor from zero to the normal limit value in the low speed region. And a limiter value control circuit.

[0019]

The current command in the stopped state is set to zero by limiting the output of the torque control amplifier in place of the conventional switch circuit, and the output limit is smoothly increased from zero to a normal limit value in the vicinity of zero speed. Eliminate the delay in the transition from stop to start and the occurrence of offset.

[0020]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a schematic view of the essential parts of an embodiment of the present invention. The torque control amplifier 15 is configured as a torque control amplifier with a limiter including the conventional limiter circuit 9. In this limiter performance, the drive current is limited to a constant value by the variable resistor 15a that generates the drive current limiting comparison voltage and the diode 15c that takes out only the drive current as the total negative feedback voltage of the operational amplifier 15b.

Further, the absorption current is limited by the variable resistor 15d and the diode 15 which generate a comparison voltage for limiting the absorption current.
and the comparison voltage of the variable resistor 15d is adjusted by the limiter value control circuit 16.

The limiter value control circuit 16 adjusts the absorption current limit value according to the rotation speed of the DC machine 3. That is, the rotation speed of the DC machine 3 is the same as that of the pulse pickup 16a.
Voltage adjustment amplifier 1 detected by the voltage converter 16b
The voltage applied to the variable resistor 16d is adjusted by 6c, which also serves as compensation for the voltage of the diode 15e.

The armature voltage compensation is set by the variable resistor 16d, and the voltage is added by adding the voltage to the output of the frequency-voltage converter 16b.

In the present embodiment, when the drive current is supplied to the DC machine 3, the torque control amplifier 15 obtains a negative output at its output to generate a current command to the current control amplifier 10, and the drive current level changes. The output is limited when the comparison voltage set by the variable resistor 15a is reached.

Next, when an absorption current is supplied to the DC machine 3, the output of the torque control amplifier 15 obtains a positive output,
This output limitation is performed by the limiter value control circuit 16. As shown in FIG. 2, this absorption current limitation is a ramp voltage that rises with a constant slope in the low speed region B ₁ where the rotation speed of the DC machine 3 is from 0 to N ₁ , and the amplifier voltage is increased in the range exceeding the speed N _1. It is set to a constant value VL ₁ due to saturation of 16c.

Therefore, the absorption current control becomes the same as the torque command zero which the conventional switch circuit 13 has at zero speed,
Prevents reverse rotation. In addition to this, when shifting from the stopped state to the start, the limiter value V _L is increased to a normal absorption current limit value V _L1 with a constant inclination as the speed increases.
This limiting operation does not cause a delay in tracking the running resistance load or an error due to the timing delay and offset of the conventional switch circuit 13.

Further, the limiter voltage V _L changes linearly, and torque shock is not generated in the running resistance load control.

It should be noted that in the embodiment, the design may be changed as appropriate, such as a configuration in which the torque control amplifier and the output limiting circuit thereof are separated, and a configuration in which the speed detection circuit of the dynamometer is used for speed detection.

Further, the same effect can be obtained by applying the torque detection of the torque control system to the configuration obtained by calculation from the electric current of the electric motor or the like.

Further, the rise from the limiter value of zero to the normal limit value is not limited to a constant slope, but may be such that the limiter value rises with a quadratic curve, as long as it gradually adjusts from the zero level to the normal limit value.

[0031]

As described above, according to the present invention, the limit value on the current absorption side of the output of the torque control amplifier is set to zero at the zero speed of the motor, and from zero to the normal limit value gradually near zero speed. Since the system is configured to raise the speed, it is possible to prevent reverse rotation at zero speed and deceleration even when the running resistance command includes an uphill command, and to eliminate tracking delay and error in torque control at start, and to reduce torque. Can be shockless.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part showing an embodiment of the present invention.

FIG. 2 is an absorption current limiting characteristic diagram in the example.

FIG. 3 is a conventional configuration diagram.

[Explanation of symbols]

 3 ... DC machine 5 ... Running resistance setting device 8, 15 ... Torque control amplifier 10 ... Current control amplifier 14 ... Voltage feedback circuit 16 ... Limiter value control circuit

Claims (1)

[Claims] 1. A torque control system controls a torque of an electric motor by using a running resistance command value of an automobile to be tested as a power absorption torque, and a current control system is provided in a minor loop of the torque control system to control a current of the electric motor. In the dynamometer, the voltage feedback circuit that controls the output of the current control system to zero when the electric motor has a voltage polarity in the reverse rotation direction, and the output of the torque control amplifier of the torque control system is limited to the electric motor. A dynamometer, characterized in that the current adjusts a limit on the power absorption side, and this adjustment comprises a limiter value control circuit for gradually increasing the rotation speed of the electric motor from zero to a normal limit value in a low speed region. Reverse rotation prevention device.