JPS605794A - Controlling method of dc motor for vehicle - Google Patents

Abstract

PURPOSE:To enable to stably raise a regenerative brake irrespective of the magnitude of a regenerative load by integrating the difference voltage between the voltage of a filter capacitor and the maximum allowable voltage from the brake notch closing time as a command value of an armature current. CONSTITUTION:A function calculator 11 outputs a request current limit value IC0 from a brake force command value BF and a speed N. An integrator 14 obtains the difference voltage between the voltage EC of a filter capacitor 4 and the maximum allowable voltage EC2, integrates in synchronization with the input of a brake notch closing signal BN, and outputs the primary command value IC1 of an armature current as the control signal value of a chopper 8. A limiter 15 suppresses the primary command value IC1 of the armature current to the request current limit value IC0 or lower, and outputs a command value IC of the armature current as a control signal of the chopper 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for controlling a DC motor for a vehicle, and more particularly to a control technique for applying regenerative braking to a DC shunt field motor by chopper control.

[Technical background of the invention and its problems]

When a DC shunt field motor used as a DC motor for a railway vehicle is controlled by a chopper device, a main circuit configuration as shown in FIG. 1 is used during regeneration. That is, in FIG. 1, 1 is a pantograph that collects current via an overhead wire (not shown), 2 is a current collection ring that collects current via rails and wheels (also not shown), 3+- is an input filter reactor, and 4 is an input filter capacitor. It is.

5 is a DC shunt field motor equipped with an armature 6 and a field saving wire 7; 8 is an armature chopper connected between both terminals of the armature 60 to control the armature current; This diode is connected in series with the overhead wire to block current flowing from the overhead wire. Furthermore, 10 is the DC shunt field electric machine's own machine 5
This is a field chopper that controls the magnetizing current given to the field winding 7 of the.

Figure 2 is a block diagram of the part that creates the current command value IC for the armature 6 in the control section that controls the main circuit shown in Figure 1, and 11 is the brake force from the driver's cab. A function calculation section calculates the current limit value ICo from the command value BF and the vehicle speed N. 12 is a limiter section that reduces the current limit value ICo according to the magnitude of the voltage EC of the filter tip 4. 13 is a limiter section for calculating the current limit value ICo. This is a first-order delay circuit that makes the movement smooth.

In FIG. 2 Oτ, the function calculation unit 11 calculates the current limit value ■Co on the notch curve necessary to obtain a predetermined brake force command value BF. FIG. 3 shows a function graph in the function calculation section 11. In other words, in order to obtain the specified braking force only with regenerative braking force, IC must be set to IC8, but if the regenerative load is small, IC-C8 must be set.
If the voltage EC of the filter capacitor 4 is given as , the voltage EC of the filter capacitor 4 rises and becomes an overvoltage. Therefore, in order to prevent this, the limiter unit 12 applies a limiter using the voltage EC of the filter capacitor 4 as shown in FIG. In other words, if the voltage EC of the filter tip 4 is less than the limiter value EC shown in Fig. 4, the output will be IC1=IC8, but E
When C, is exceeded, IC1 is reduced along the straight line shown in FIG. 4, and becomes Ic=0 at the maximum limiter value EC2.

Although this action prevents an overvoltage of the voltage EC of the filter capacitor 4 when the regenerative load is small, this control method has the following problems. In other words, when regenerative braking is started when the regenerative load is low, as shown in Figure 5, the current command value IC will overshoot once and then be reduced by the limiter, so this overshoot will temporarily reduce the harmonization with air braking. There was a problem in which the brake could not be braked stably. In order to prevent this, a method of increasing the time constant T of the first-order delay circuit 130 can be considered, but with this method, even if there is a sufficient regenerative load, the start-up of regenerative braking is delayed, and the electric braking and air braking Problems may occur such as sliding due to laps and reduced regeneration efficiency.

[Purpose of the invention]

The present invention has been made in view of the above points, and when applying regenerative braking to a DC shunt field motor using chopper control, the regenerative braking can be started stably without delay, regardless of the size of the regenerative load. The present invention provides a method for controlling a DC motor for a vehicle.

[Summary of the invention]

The present invention uses a DC shunt field motor as a main motor for a vehicle, and when a filter capacitor is installed to chopper control the armature current of the DC shunt field motor to perform regenerative braking, the filter capacitor Measure the voltage of the filter capacitor, calculate the difference between the measured actual voltage of the filter capacitor and the predetermined maximum allowable voltage of the filter capacitor, integrate this voltage difference from this point in synchronization with the application of the brake notch, and calculate the voltage of the electric motor. The above object is achieved by setting the command value of the armature current as the command value of the armature current and limiting the required current limit value to the maximum value using a predetermined method from the brake force command f1 and the speed.

[Embodiments of the invention]

An embodiment of the present invention will be explained below with reference to the drawings.

FIG. 6 is a control block diagram illustrating an embodiment of the present invention, in which the limiter section 12 in the control block diagram shown in FIG.
In this example, an integrator 14 and a limiter 15 are provided in place of the first-order delay circuit 13.

In FIG. 6, the function calculator 11 is exactly the same as the function calculator in the control block diagram shown in FIG.
A required current limit value ICo is output by performing functional calculations from F and speed N using a predetermined method shown in FIG.

Integrator] 4, the filter capacitor 4 shown in FIG.
Input the voltage EC, find the predetermined and memorized maximum allowable weight of the filter capacitor, and calculate the differential voltage with respect to the pressure EC2.
Brake notch input signal BH input and synchronization formula (1)
The integral meter is tightened as shown in FIG. 1, and the primary command value IC of the armature current is outputted as a control signal for the Nayopper sieve 8 that controls the current in the armature 6 shown in FIG. The initial value of l at which control of IC1 is started is zero.

However, K is a constant and t is time.

The limiter 15 is a limiter that suppresses the primary command value IC of the armature current outputted by the above-mentioned integrator 14 to below the required current limit value IC8 from the function calculator 11, and controls the chopper device 8. Outputs the armature current command value IC as a signal.

Voltage E'C of filter capacitor 4 and armature current command value IC at the start of regenerative braking in the control method of the present invention
The state is shown in FIGS. 7 and 8. FIG. 7 shows a case where the regenerative load is small, and FIG. 8 shows a case where there is a sufficient regenerative load.

In FIG. 7, since the regenerative load is small, regenerative power suppression is started and the command value IC of the armature current increases from O due to the action of the integrator 14, and the voltage EC of the filter capacitor 4 increases.
will also increase. Therefore, as is clear from the calculation formula (1) of the integrator 14, the manner in which the command value IC of the armature current increases gradually becomes smaller.

Then, when the voltage EC of the filter capacitor 4 becomes E C=EC2 with respect to the maximum allowable voltage EC2, the output of the integrator 14 stops changing. Due to this action, the command value IC of the electric current and electric current does not overshoot as shown in Fig. 5, and becomes EC-EC2, that is, regenerative braking is performed with the highest regenerative efficiency within the allowable range. .

If the regenerative load increases on the way, filter capacitor 4
Since the voltage EC decreases, the υ minute g614 increases the output again, and holds the command value IC of the armature current when E C=E C2 as described above. Conversely, when the regenerative load decreases, the voltage E of filter capacitor 4
Since C increases, the integrator 14 decreases its output until it becomes EC2, and holds the output when EC=gc2.

In Fig. 8, since there is sufficient regenerative load, regenerative braking is started and the command value IC of the armature DC is calculated by the action of the integrator 111.
Even if increases from zero, the voltage EC of the filter capacitor 4
It doesn't rise too much. Therefore, the integrator 14 gradually increases its output until it reaches C1-C0. Here, due to the action of the limiter 150, IC-■c.

is clamped, and regenerative braking is performed in that state.

[Overall effect]

As explained above, the present invention 1c allows the regenerative braking of the DC shunt motor to start up stably regardless of the regenerative load, and also allows the filter capacitor voltage to always match the allowable value when the regenerative load is small. The most efficient regeneration can be achieved by controlling the

[Brief explanation of drawings]

Figure 1 is a diagram showing the main circuit configuration during regeneration for chopper control of a DC shunt field motor, Figure 2 is a control block diagram for calculating the conventional armature current command value, and Figures 3 to 5. The figure is an explanatory diagram of the operation of Figure 2, Figure 6 is a control block diagram for calculating command values for electric machine pre-current and current according to an embodiment of the present invention, and Figures 7 and 8 are explanations of the operation of Figure 6. This is a diagram of Nodame. 5... DC shunt field motor 6... DC shunt field type, motor armature 8... Chopper device 11... Function calculation section 14... Integrator 15... Limiter ( 7317) Agent Patent Attorney Noriyuki Chika (and 1 other person) Figure 3 IC/ Figure 4

Claims (1)

[Claims] In a control method for a vehicle DC motor in which a filter capacitor is installed and the armature current of a DC shunt field motor is chopper-controlled to perform regenerative braking, the voltage of the filter capacitor is measured, and the measured actual voltage of the filter capacitor is Calculate the difference between the voltage and the predetermined maximum allowable voltage of the filter capacitor, integrate this voltage difference from the time when the brake notch is applied, and use it as the armature current command value, and use this armature current command value as the brake 1. A method for controlling a direct current motor for a vehicle, characterized in that the maximum value is a required current limit value determined from a force command value and a speed using a predetermined method.