JPH022395B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a chopper control device, and is particularly suitable for application to an electric vehicle equipped with a brake device having a regenerative brake chopper and a resistance brake chopper. The main circuit of this type of electric vehicle is one that forms a circuit as shown in FIG. 1 in the brake mode. In Fig. 1, A1 and A2 are the armatures of a two-phase electric motor, and in regenerative braking mode, when the main choppers CH1 and CH2 are on, the armature A1 - current cutter L4 - field F1 - F2
- Smooth reactor MSL1 - Main chopper CH1
- High speed circuit breaker HB1 - Series resistor R - Loop of armature A1 and armature A2 - Current interrupter L3 - Field F3 -
F4-Smooth reactor MSL2-Main chopper
Main chopper CH1 and
A current I ₁ is applied to CH2 (Fig. 2A).

On the other hand, main chips CH1 and CH2
When is off, armature A1 - disconnector L4 - field F1
-F2-Smoothing reactor MSL1-Flywheel diode FWD1-Filter capacitor CF-
High-speed circuit breaker HB1-resistor R-loop of armature A1, armature A2-disconnector L3-field F3-F4-
A current I2 is passed through the filter capacitor CF through the smoothing reactor MSL2 - flywheel diode FWD2 - filter capacitor CF - fast circuit breaker HB1 - resistor R - armature _A2 loop (second
Figure B), the energy of the filter capacitor CF is transferred between the filter reactor LF and the main current interrupter LB.
- the main current is sent to the overhead line R _f via the high-speed circuit breaker HB2; Therefore, regeneration is achieved by using other vehicles VL connected to the overhead wire R _f (the presence or absence of a vehicle is equivalently represented by a current interrupter LL, and the magnitude of the load when a vehicle is present is represented by a variable resistor RL). Generated energy can be regenerated into the brake load.

To switch from the regenerative brake mode to the resistance brake combined mode, the main choppers CH1 and CH2 are turned off, and the resistance brake choppers BCH1 and BCH2 are turned on. At this time, armature A1 - disconnector L4 - field F1 - F2 - smoothing reactor MSL1 - resistance brake chopper BCH1 - high speed circuit breaker HB1 - resistor R
- loop of armature A1 and armature A2 - current interrupter L
3-Field F3-F4-Smoothing reactor MSL2-
Resistance brake chopper BCH2-high speed circuit breaker HB1
- resistance R - the loop of armature A2 and through the current I ₃
(Figure 2C). Here, the resistance brake chips BCH1 and BCH2 have built-in resistors and reactors, and are configured to consume generated energy.

In this way, in the main circuit of the electric vehicle with the configuration shown in Figure 1, the entire arc extinguishing area of the main choppers CH1 and CH2 is switched from the regenerative brake mode to the combined resistance brake mode and back at once. , at the time of switching, the current flowing into the filter capacitor CF suddenly changes. As a result, the voltage E _c of the filter capacitor CF oscillates (D in FIG. 2), making it uncontrollable and also exceeding the overvoltage detection level EL.

The present invention is an attempt to solve the above-mentioned problem, and is a chopper control device that can smoothly switch from regenerative brake mode to resistance brake combination mode without causing a sudden change in the inflow current in the filter capacitor. The purpose is to provide

Embodiments of the present invention will be described below in detail with reference to the drawings.The configuration shown in FIG. 3 is used as the control circuit CON for the resistance brake choppers BCH1 and BCH2.

In Figure 3, timer 1 has a sampling period τ
A trigger signal is output to the calculation control section 2 at every interval. The input section 3 inputs a switching signal from the regenerative brake mode to the resistance brake combination mode or a return signal from the resistance brake combination mode to the regeneration brake mode, and outputs it to the storage section 4 . The storage section 4 stores the switching signal or return signal coming from the input section 3 as condition information.

The arithmetic control unit 2 contains programs P1 and P2 shown in the flowcharts of FIGS. 4 and 5, which are activated at sampling period τ intervals by a trigger signal from the timer 1. When the activation is applied, condition information is retrieved from the storage unit 4, and if the content indicates switching from regenerative brake mode to resistance brake combination mode, the switching program P1 shown in FIG. 4 is executed to switch to regenerative brake mode. Switch from to resistance brake combination mode.

The switching program shown in Figure 4 consists of processing steps.
Executed from S0, the processing step switches from regenerative brake mode to resistance brake combination mode.
A series of processes from processing steps S1 to S9 are executed at sampling period τ intervals until flag F2 becomes F2="1" in S16.

Furthermore, when the condition information is retrieved from the storage unit 4 and the content indicates a return from the resistance brake combined mode to the regenerative brake mode, the program shown in FIG. 5 is executed to change the resistance brake combined mode to the regenerative brake mode. Return to mode.

When the programs shown in Figs. 4 and 5 are executed in this way, the power generation brake chips BCH (BCH1 and BCH1 in Fig. 1) are
The number of pulses β corresponding to the extinction region of BCH2) and the gate command are output to the digital phase shift circuit 5. At this time, if the gate command is logic "1", the digital phase shift circuit 5 digitally determines the phase shift and width of the on-pulse synchronized with the chopper frequency based on the above-mentioned pulse number β, and outputs it via the pulse amplifier circuit 6. resistance brake tippa
Output to BCH gate. Pulse amplifier circuit 6
amplifies the gate pulse of the digital phase shift circuit 5 to a magnitude that can drive the gates of the resistive brake choppers BCH1 and BCH2.

The variables used in the program P1 shown in FIG. 4 and the program P2 shown in FIG. 5 described above are determined as follows. In Figures 6 and 7, l ₁ is the chopper period, α is the main chopper CH
The ignition time and β _{nio pff} respectively indicate the minimum extinguishing time required for the main chopper CH to extinguish, and this time β _{nio pff} is the resistance brake chopper CH.
Represents a prohibited zone in which BCH cannot be fired. Incidentally, as shown in FIG. 7B, the resistance brake chopper BCH has a maximum firing time β _{nax po} when it has a forbidden zone β _{nio pff} . Also β _{nax pff}
represents the maximum extinguishing time of the resistive brake chopper BCH, and in this case, the resistive brake chopper BCH has the minimum firing time β _{nio po} . l ₂ indicates the arc extinction time of the main chopper CH.

First, program P1 has the following contents. In Fig. 4, flags F1 and F2 are cleared at step S0 to set F1 = "0" and F2 = "0", and the next step is started.
After inputting the firing time α of the main chopper CH in S1, the maximum extinction time β _{nax pff} (=l ₁ −α−
β ₃ ) is determined.

Next, in step S3, it is determined whether the flag F1 is logic "1" or not. If a negative judgment result is obtained, the process moves to step S4 and sets the maximum arc extinguishing time β _{nax pff} obtained in step S2 to the minimum point of the resistance brake chopper BCH. In order to give it as an arc time, it is set to a set value β _i (β _i =β _{nax pff} ), the gate signal is set to "1" in the next step S5, and then the flag F1 is set to "1" in step S6. After that, in step S7, the set value β _i is converted to the number of pulses β corresponding to the extinguishing time, and then in step S8, the firing time α in the current sampling period is reset to α ₀ .
In S9, the set pulse number β and the gate signal are output to the digital phase shift circuit 5.

When the operation in the first sampling period is thus completed, steps S1 and S2 are executed again after the next sampling period τ. At this time, in the next step S3, the flag F1 is set to F1="1", so the process moves to step S10. In step S10, the decrease value _Δβ1 is subtracted from the set value β _i set in step S4 to obtain a new set value β _i .

However, in the next step S11, the current firing time α and the previous firing time α (hereinafter referred to as α ₀ ) are compared, and it is determined that the firing time for the resistance brake chopper BCH is greater than the firing time corresponding to Δβ ₁ . The set value β _i is corrected by the amount of change in the ignition time α so as not to change. If the ignition time α decreases, the amount of change is added as β _i =β _i +(α ₀ −α) in step S12, and if the ignition time α increases, β _i =β _i −( α
−α ₀ ) and subtract the amount of change in the ignition time α.

Next, in step S14, a comparison is made to see if β _i has reached the minimum arc extinguishing time β _{nio pff} .
If the maximum arc extinction area of CH has not been reached,
Step S17 is executed to compare β _i with the maximum arc extinction area β _{nax pff} , and if β _i exceeds β _{nax pff} , a correction is performed in step S18 as β _i =β _{nax pff} .

After executing steps S7 to S9 described above and completing the operation in the current sampling period, step S1 for the next sampling period is executed again.
Move on to execution. On the other hand, if it is determined in step S14 that β _i has reached the minimum value β _{nio pff} ,
After β _i =β _{nio pff} is set in step S15, the flag F2 is set to "1" in step S16, and thus the switching program P1 at the time of switching from the regenerative brake mode to the resistance brake combined mode is completely completed.

Next, the procedure for executing the return program P2 when switching from the resistance brake combined mode to the regenerative brake mode is to first set the flag F3 and
Clear F4 to set F3="0" and F4="0", set the firing time α of the main chopper CH in step S20, and set the flag F3="0" in step S21.
If a positive result is obtained, the flag F3 is set to "1" in step S22, the ignition time α is set to the previous ignition time _α0 , and the program P1 described above is executed. After determining the maximum arc extinction time β _{nax pff} in the same manner as in the case, step S24
In order to increase the extinction time β _i of the resistance brake chopper BCH, an increase value Δβ ₂ is added to the previous value β _i to obtain a new value β _i .

Next, in step S25, the current ignition time α and the previous ignition time α ₀ are compared, and if the current ignition time α has decreased as in the case of program P1 described above, β _i is determined in step S26. = β _i + (α ₀ - α), and if the ignition time increases, β _i = β _i - (α ₀
−α). Then step S28
The arc extinction time β _i is compared with the minimum arc extinction time β _{nio pff} , and if β _i <β _{nio pff} , β _i =
β _{nio pff} is set and compared with the maximum value β _{nax pff} in step S30. The result is a resistance brake tippa
If the firing time of BCH is not minimized, β _i
<β _{nax pff} , so in step S32 the value β _i
is converted into a pulse number β and outputted to the digital phase shift circuit 5 in step S33.

Further, in step S34, it is determined whether flag F4 is "1" or not, and when it is determined that F4 is "0", the operation for the current sampling period is completed, and then the process returns to step 20, and the process for the next sampling period is performed at step 20. Repeat the operations from to step 35.

On the other hand, when it is determined in step S30 that the firing time of the resistance brake stopper BCH is the minimum,
β _i ≧ β _{nax pff} , and in step S31 β _i = β _{nax pff}
,
F4=“1”. Therefore, at step S35, press F4.
= "1" is detected, so steps S36 and S37
are sequentially executed, and the state of GATE="0" is output to the digital phase shift circuit 5, thus completing the execution of the return program P2 when switching from the resistance brake combination mode to the regenerative brake mode.

As described above, according to the switching program P1 when switching from the regenerative brake mode to the resistance brake combination mode, the firing time of the resistance brake chopper BCH changes as shown in FIGS. 8 to 18.

That is, in FIG. 8, when β _i =β _{nax pff} , the resistance brake chopper BCH reaches its minimum firing. t
As seconds pass, as shown in FIG. 9, β _i decreases and the ignition range of the resistance brake stopper BCH increases. If the firing time α of the main chopper CH decreases after the next sampling period τ, β _i will change to the value obtained by subtracting Δβ _i from the previous β _i as shown in FIG. α−α ₀ ) is added to prevent the firing range of the resistance brake stopper BCH from changing suddenly.

On the other hand, when the ignition time increases, the extinguishing time β _i is determined by subtracting Δβ _i from the previous extinguishing time β _i , and then the amount of change in the ignition time α (α − α ₀ )
Subtract. When the subtracted arc extinction time β _i reaches the maximum arc extinction time β _{nax pff} , this maximum arc extinction time β _{nax pff} is given to ensure the minimum firing time β _{nio pff} .

Next, when the ignition time α changes from the state shown in FIG. 12 to the state shown in FIG. 13 during one sampling period, the extinction time β _i
After subtracting Δβ _i from , the amount of change in ignition time α (α
−α ₀ ) is subtracted to prevent the firing range of the resistance brake stopper BCH from changing suddenly.

Also, as shown in Fig. 14, when the arc extinction time β _i reaches the minimum arc extinction time β _{nio pff} , the resistance brake chopper
The maximum ignition time β _{nax po} will be given to BCH, and from then on β _{nio pff} will be maintained.

In this way, when switching from regenerative brake mode to resistance brake combined mode, the firing period of the resistance brake chopper is set to its maximum period βmax on.
The change in arc extinguishing period βi is specified as Δβi and is increased by a predetermined value within a range not exceeding . When the firing period α of the main chopper CH fluctuates, the extinction period βi is increased or decreased accordingly to obtain a predetermined firing period of the resistance brake chopper BCH within the range of the extinction period of the main chopper CH. It is done like this.

Therefore, at the beginning of switching, within one chopper cycle, after the main chopper CH is fired,
Within the arc extinction period of this main chopper CH, the resistance brake chopper BCH has a maximum arc extinction period βmax
off and fires with the minimum firing period βmin on, and as time passes, its main
Resistance brake chopper during CH arc extinction period
The extinction period of the BCH will be reduced and the firing period will be increased as a result.

Along with this, the period of current flowing into the capacitor CF corresponding to the firing period of the resistive brake chopper BCH also gradually increases, so that the voltage oscillation of this capacitor CF can be suppressed, and this oscillation causes It is possible to prevent the voltage from exceeding the overvoltage detection level.

On the other hand, in the case of program P2 for returning from the resistance brake combination mode to the regenerative brake mode, the state shown in FIG. 14 gradually changes to the state shown in FIGS.
The state shown in Fig. 18 is reached after passing through the states shown in Figs. As in the case of switching from the regenerative brake mode to the resistance brake combination mode, by being able to avoid sudden changes in the firing range of the resistance brake chopper BCH, an increase value Δβ _i is added to the previous extinguishing time β _i , and the firing Amount of change in time α (α ₀ − α)
Correction is performed by adding . Conversely, if the ignition time α increases as shown in Figure 17, add the increase value Δβ _i to the previous extinguishing time β _i and subtract the amount of change in the ignition time α (α − α ₀ ). Correction is made by doing this.

As described above, according to the present invention, when switching from regenerative brake mode to resistance brake combination mode,
First, the firing period of the resistance brake chopper is set as its minimum firing period, and then the firing period of the resistance brake chopper is increased by a predetermined value within a range that does not exceed the maximum firing period every sampling period, so the regenerative brake The mode can be smoothly switched from the resistance brake combination mode to the resistance brake combination mode without causing a sudden change in the current flowing into the filter capacitor in the main circuit. Therefore, vibrations in the voltage E _c of the filter capacitor CF can be suppressed to a minimum, and since a digital computer can be used, calculation accuracy can be improved, so that controllability can be further improved. Incidentally, by using a low-cost processor such as a microcomputer, maintainability, performance, and flexibility can be further improved.

[Brief explanation of drawings]

FIG. 1 is a connection diagram showing the main circuit of the electric vehicle, FIG. 2 is a signal waveform diagram for explaining its operation, FIG. 3 is a block diagram showing an example of the control circuit of the chopper control device according to the present invention, and FIG. 4 and 5 are flowcharts showing the switching program P1 and return program P2, FIGS. 6 and 7 are curve diagrams showing variables, and FIGS. 8 to 18 are explanations of the response operation of the resistance brake chopper. FIG. A1, A2...armature, F1-F4...field,
MSL1, MSL2...Smoothing reactor, CH1,
CH2, CH……Main chiyotsupa, BCH1, BCH
2, BCH……Resistance brake tippa, FWD1,
FWD2……Flywheel diode, CF……
Filter capacitor, LF...Filter reactor, R _f ...Overhead line, VL...Regenerative brake load, 1
...Timer, 2...Arithmetic control section, 3...Input section,
4...Storage unit, 5...Digital phase shift circuit, 6...
...Pulse amplifier circuit.

Claims (1)

[Scope of Claims] 1. A chopper control device having a switching control circuit for switching a braking device having a regenerative brake chopper and a resistance brake chopper from a regenerative brake mode to a combined resistance brake mode, wherein the switching control circuit is configured to switch a braking device having a regenerative brake chopper and a resistance brake chopper from a regenerative brake chopper to a combined resistance brake mode. means for generating a switching command from to a resistance brake combined mode; means for generating a starting signal at a predetermined sampling period; and upon receiving a starting signal that is the first starting signal after receiving the switching command. means for setting a minimum firing period as an initial value of the firing period of the resistance brake chopper; and means for setting a minimum firing period as an initial value of the firing period of the resistance brake chopper, and a means for setting the firing period of the resistance brake chopper to exceed the maximum firing period each time it receives each starting signal after the first starting signal. 1. A chipping control device characterized by comprising: means for increasing by a predetermined value within a range where the chipping is not performed.