JPS6013361B2 - Regeneration control method for AC electric vehicles - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a regenerative braking control system used in AC electric vehicles.

FIG. 1 is a circuit diagram showing a typical example of a regenerative braking circuit for an AC electric vehicle. During regenerative braking, the armature windings M, 2 and field windings MF, 2 of a DC series motor are separated. Be independent,
So-called separately excitation shunt control is performed.

The armature winding circuit is composed of a main rectifier MRf, 2 composed of a thyristor bridge, a DC circuit or disconnector L, and a main smoothing reactor MSL. Then, the voltage generated in the armature windings M, 2 of the main motor operated as a generator overcomes the DC output voltage of the main rectifier, the so-called inverter voltage, and supplies current to the secondary winding of the main transformer MT. Pour. As a result, a voltage is induced in the primary winding of the main transformer MT, causing a so-called regenerative operation in which the current in the opposite direction to the power source is passed through the AC circuit and into the overhead wire via the disconnector CB and the pantograph (Pan). Let's do it. On the other hand, the field winding circuit MF, 2 is a field rectifier B composed of a thyristor and a diode connected to the dedicated winding of the main transformer MT.
It is excited by Rf.

FIG. 2 shows an example of a control block, in which the skin pattern generator 1, IA
Comparator 2, IF maximum detector 3, IA detector 4, phase shifter 5
, an IF detector 6, an electric brake torque detector 7, an IF pattern generator 8, an IF comparator 9, a phase shifter 10, and a brake torque calculator 11.

Next, using FIG. 2 to explain the control when a brake torque is commanded by a brake valve or the like, when a predetermined brake torque is commanded by a brake valve or the like, the IA pattern generator 1 will respond accordingly. An armature current pattern (also referred to as a current limit value) is generated, and an IF pattern generator 2 generates a field current pattern.

The voltage FM generated by the main motor during regenerative operation and the current peak are related to the following equation (1). Main motor generated voltage EM: Otoboshi no I. (E, 10E2)・COSY10Ex10E
s1R・IA...'1}E,, 2: AC effective voltage of each secondary winding of the main transformer [V] y: Control advance angle of thyristor [
0] Ex: Commutation reactance drop of the main transformer [V] Es: Forward voltage drop of the main rectifier [V] R: Internal resistance of the DC circuit [Q] France: Electrical viscous current of the main motor [A] EM ? ×N's "×N......■ Brake torque BE? ×lAMIF×Mountain...'3'? : Field magnetic flux of the main motor [Wb] and field current of the three main motors [A
] N: Vehicle speed [rat/n] In order to perform inverter operation of the main rectifier, a control advance angle (also called minimum commutation margin angle) of a certain level or more is required, so in high speed regions the main motor It is necessary to reduce the generated voltage EM to satisfy the above equation {1}.

Therefore, the field voltage EM of the main motor is controlled to control the voltage EM generated by the main motor. Therefore, when a brake command is issued, the small motor voltage [empty] is applied. (E, 10E2)・
The phase of the thyristor of the field rectifier BRf is controlled so that the field current changes from the minimum value to the maximum value while maintaining the maximum COW. After the IF maximum detector 3 detects that the field current has reached its maximum, the string Isogo current should be kept constant as the speed decreases while keeping the field current constant.
, the main rectifier MRf,, to control the inverter voltage.
The phase of the second thyristor is controlled. This situation will be explained using the brake curve diagram in FIG. 3. When maximum braking is commanded, the curve becomes like curve 2, and when weak braking is commanded, the curve becomes like curve 2. In general, the maximum magnetic field current IF at the time of the maximum brake command is set to be the same as the electric field current IF (IF,=IA,). By the way, even when a weak brake command is issued, the field rectifier is controlled until the maximum field current IF is reached as shown in curve (2), and then the isoverter voltage is controlled. It will be operated in state 1 where the current is small, resulting in a very overexcited state.
IA2) or the armature current may become intermittent. Therefore, in the present invention, if
A / peak comparator is provided to make the Kanisogo electric current IF and the Kaiji current IF the same during inverter voltage control in a low speed region.

Hereinafter, it will be explained in detail using the drawings. FIG. 4 is a block diagram showing one embodiment of the braking system according to the present invention, and
The difference from the figure is that "maximum detector 3 is replaced by IF peak comparator 12".
This is what happened.

In a circuit configured in this way, when a brake command is issued, the field current is gradually increased from the minimum value while maintaining the inverter voltage at the maximum, as in the past, but as the speed decreases, the field current increases gradually. Electric current and Denki Viscount style match. In other words, when the F/IA comparator 12 outputs an output, the field current is maintained at that state, and the thyristor of the main rectifier MRf is phase-controlled so that the armature current peak is constant, and the isobverter voltage is adjusted to the speed. Control accordingly. In this way, the Denki Viscount flow [IA] will not become extremely small, so
Intermittent armature current and over-excitation of the main motor can be resolved. As explained above, the regenerative braking system for an AC electric vehicle according to the present invention is provided with an IF/IA comparator so that the electric current and the field current become the same in the low speed range and while the inverter voltage is being controlled. Since it is controlled, it has an excellent effect of being able to prevent the armature current from intermittent, and also being able to eliminate overexcitation of the main motor.

[Brief explanation of the drawing]

Figures 1 and 2 are circuit diagrams showing an example of a regenerative braking system for an AC electric vehicle, Figure 3 is a characteristic diagram thereof, and Figure 4 is an embodiment of an AC Kameyama pressure summer regenerative braking system according to the present invention. FIG. Note that the same reference numerals in the figures indicate the same or corresponding parts. P
an...Pantograph, CB...AC circuit and disconnector, MT...Main transformer, MRf,, 2...Main rectifier, L
,,2...DC separation or disconnector, MSL...main smoothing reactor, BRf...rectifier for field energy, M,. 2...
・Armature of main motor, MF, 2... Field winding of main motor, 1... 1st evening generator, 2... IA comparator, 4... IA detector , 5...Phase shifter, 6...IF detector, 7...Electric brake torque detector, 8...IF pattern
generator, 9...IF comparator, 10...phase shifter, 11...
Brake torque calculator. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1 In an AC electric vehicle that performs regenerative braking by inverter operation of a thyristor bridge, when a brake command is issued, the field current of the traction motor is compared with the armature current of the traction motor while maintaining the inverter voltage at maximum, and the a comparison means for outputting an output when they match; a control means for controlling the phase of the thyristor of the field rectifier so as to keep the field current of the main motor constant by the output of the comparison means; A regeneration control system for an AC electric vehicle that includes a control means that controls the inverter voltage to a voltage that corresponds to the speed by controlling the phase of the thyristor in the main rectifier so that the current is constant.