JPH03105230A - Roller dynamometer - Google Patents

Abstract

PURPOSE:To enable stable operation, control and measurement with a reduction in torque variations at a low speed by connecting phases of stator windings of one pair of dynamometers in series for a delta or star connection to improve a load balance. CONSTITUTION:To drive first and second dynamometers 15 and 16, current is supplied to stator windings U1-W1 and U2-W2 of the dynamometers 15 and 16 from an inverter INV. The current flows through the windings U1-W1 and U2-W2 of phases. At this point, as the windings U1-W1 and U2-W2 have the windings of phases connected in series, no unbalanced current flows to cancel a difference among winding impedances. This can improve a load balance of the dynamometers 15 and 16 thereby achieving a stable operation.

Description

[Detailed Description of the Invention] A. FIELD OF INDUSTRIAL APPLICATION This invention relates to a roller dynamometer used for vehicle testing.

B. Summary of the Invention The present invention provides a roller dynamometer in which first and second rollers arranged in parallel in the axial direction are connected, the first and second dynamometers are housed within both rollers, and the stators of both dynamometers are connected. Each phase of the winding is connected in series in delta connection or star connection and connected to an inverter to improve load balance during tandem operation and reduce torque ripple at low speeds for stable operation.
This allows for control and measurement.

C. Conventional technology Chassis dynamometers used for vehicle performance tests (running resistance, climbing boards, vehicle weight, etc.) can easily conduct experiments indoors with good reproducibility that are equivalent to driving on an actual road. It is widely used for tests and fuel consumption tests. In addition, the dynamometer needs to control torque, and also has driving functions for warming up equipment (rollers, flywheels, etc.), compensating for mechanical loss, and compensating for electrical inertia.

Therefore, when using a chassis dynamometer, there are many matters that must be managed, including the settings of rotational speed and torque, due to the above-mentioned tests and functions. Therefore,
If these controls are inappropriate, a satisfactory test will not be possible. In particular, recently, in order to reduce the installation area of a chassis dynamometer, roller dynamometers in which dynamometers are housed inside a pair of rollers have come into use. This roller dynamometer could not be tested satisfactorily, especially if the torque and rotational speed were improperly controlled.

D. Problems to be Solved by the Invention In order to satisfy the above test, it has come to be considered that a flex dynamometer (FCDY) is housed inside the roller. However, when the fleck dynamometer is operated in tandem, the dynamometer is connected to the inverter rNV as shown in FIG. 4, so a large amount of unbalanced current flows due to the difference in winding impedance. This causes a problem of load imbalance between the pair of dynamometers, resulting in local heating and torque fluctuations. Furthermore, if the flex dynamometer is housed within the roller, there is a limit to its capacity.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a roller dynamometer that improves load balance, reduces torque fluctuations that occur at low speeds, and enables stable operation, control, and measurement. With the goal.

E. Means for Solving the Problems This invention provides a first wheel on which the drive wheels of a test vehicle are mounted. A second roller is arranged in parallel in the axial direction and both rollers are connected by a coupling, and first and second dynamometers are housed inside both rollers, and the rotors of the first and second dynamometers are arranged in parallel. In a chassis dynamometer in which an iron core is disposed on the outer periphery of a stator iron core and a rotor iron core is attached to the inner peripheral surfaces of first and second rollers, the three-phase stator of the first and second dynamometers is provided. The present invention is characterized in that windings are connected in series for each phase to form a delta connection, and an inverter device is connected to each phase connection point of the delta connection.

In addition, the three-phase stator windings connected in delta are switched to star connected.

F. Since the working stator windings are connected in series for each phase in a delta connection or star connection, differences in winding impedance can be canceled out. This operation balances the load and suppresses torque fluctuations.

G. Example Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic diagram showing an embodiment of a roller dynamometer, with parts cut away. In this Figure 1 I, 11
．． 12 is the first. In the second roller, both rollers 11, 12 are supported by rotary bearings 13a, 13b and 14a, 14b. Inside the first and second rollers 11 and +2, there is a first roller.
．． Second dynamometers 15 and 16 are housed.

The first and second dynamometers 15 and 16 are the stator core 1
Rotor core on the outer periphery of 5a and 16a! 5b, 16b are arranged, and the rotor cores 15b, 16b are arranged in the first. It is attached to the inner peripheral surfaces of the second rollers 11 and 12. The stator cores f5a, 15b of the first and second dynamometers 15, 16 are fixed to swing shafts 17, 18, and the swing shafts 17, l8 are provided on the first and second rollers 11, 12. The swing bearings 19a, 19b and 20a. 20b.

The first and second rollers If, 12 are connected to a coupling 21, 22 by a connecting shaft 23. 24 is a load cell attached to the swing shafts 17 and 18 via a torque detection rod 24a, and 25 is a pulse pickup for speed detection.

In Figure 1, U. ,V,,W. and Ut, Vt, Wt
is the first. The three-phase stator windings of the second dynamometers 15 and 16 are shown taken out to the outside, and these windings U1
~W, and U, ~W, are not shown, but the swing shafts 17, 1
It is drawn out to the outside through a hollow portion formed at 8.

The stator windings U, ~W, and U, ~W are connected to each phase U, U, , ■, and V, and W1 and W, as shown in Fig. 2.
, are connected in series and connected in delta.

Connection points Cr, Ct, and C3 of the delta-connected phases are connected to an inverter INV to operate as a fleck dynamometer.

Next, the operation of the above embodiment will be described.

In order to drive the first and second dynamometers 15 and 16, current is supplied from the inverter device INV to the stator windings U, ~WI and U2~W of the first and second dynamometers 15 and 16. . The supplied current flows through each phase winding U, ~W1
and flows to U, ~W.

At this time, each phase winding U1 to W1 and U, to W, are connected in series as shown in Figure 2, so no unbalanced current flows because the difference in winding impedance is canceled out. . For this reason, the first and second dynamometers 15 and 16
The load balance is improved and stable operation is possible.

When the first and second dynamometers 15 and 16 are at low speeds, operate a pole switch (not shown) to change the connection from the delta connection in Figure 2 to the star connection in Figure 3. Increase the number of poles from 6 to 12.

If the first and second dynamometers 15 and 16 are driven using a star connection as shown in FIG. 3, torque ripple (fluctuation) at low speeds can be prevented.

H. Effects of the Invention As described above, according to the present invention, each phase of the stator windings of the first and second dynamometers is connected in series for delta connection or star connection, thereby achieving good load balance. Stable operation. This has the advantage of being able to control and measure, as well as preventing torque fluctuations at low speeds.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway schematic configuration diagram showing an embodiment of the present invention, FIG. 2 is an explanatory diagram when the stator windings of the first and second dynamometers are connected in delta, and FIG. The figure is an explanatory diagram when the stator winding is star-connected, and FIG. 4 is an explanatory diagram of the conventional stator winding. 11.12...first and second rollers, 15.16...
・First. Second dynamometer, 15a, 16a...
Stator core, 16a, 16b...rotor core, U+,
Ut, V+, Vt, W1, Wt”・Stator winding of each phase.

Claims (2)

[Claims] (1) The first and second rollers on which the drive wheels of the test vehicle are placed are arranged in parallel in the axial direction, and both rollers are connected by a coupling, and the first and second dynamometers are installed inside both rollers. A chassis dynamometer in which the rotor cores of the first and second dynamometers are arranged around the outer periphery of the stator core, and the rotor cores are attached to the inner peripheral surfaces of the first and second rollers. The three-phase stator windings of the first and second dynamometers are connected in series for each phase to form a delta connection, and an inverter device is connected to each phase connection point of the delta connection. A roller dynamometer featuring: (2) The roller dynamometer according to claim 1, wherein the three-phase stator winding is connected in a delta connection and is connected in a star connection.