JPS6173584A - Controlling method of power regenerative circuit - Google Patents

Abstract

PURPOSE:To improve the regenerative efficiency by composing a reverse regenerative bridge for regeneration of a self-extinguishing element, and controlling the element suitably in the prescribed phase range of phase voltages. CONSTITUTION:Current commands 11a-11c of phases are respectively input to comparators 12a-12c. The outputs of the comparators 12a-12c and the output of a current detector 3 are processed by an OR gate 12, an inverter 13, a NAND gate 15, an AND gate 16 and an amplifier 17 to form a control signal of a reverse regenerative bridge self-extinguishing element SU. The ele ment SU is controlled ON and OFF between 0 deg.-60 deg. and 120 deg.-180 deg. of 180 deg. width of phase voltages, and held in firing state between 60 deg.-120 deg..

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method of controlling a power regeneration circuit using self-extinguishing elements such as transistors and GTOs (gate turn-off thyristors).

[Conventional technology]

FIG. 3 is a block diagram showing the configuration of a conventional one-pressure inverter device. In this figure, 1 is a three-phase AC power supply,
2 is a current limiting reactor, 3 is a current detector, 4 is 6 ([
A roundworm bridge (hereinafter referred to as reverse RF) consisting of i2 transistors 8U-8Z, 5 is 6 diodes DU ~
iK mudflow conversion bridge (hereinafter referred to as positive RF) consisting of DZ, 6 is a smoothing electrolytic capacitor, 7 is a deviation detection point for output from six transistors and a feedback diode connected in antiparallel to each of the transistors, 10 is a This is a control circuit that controls on/off of each transistor 5U-8Z of reverse RF4.

In such a configuration, when the electric motor 8 is driven from its load side, it acts as a generator, and this generated RL force is regenerated into DC 1111 via the inverter 7, charging the electrolytic capacitor 6 and increasing the DC voltage. do. In order to avoid this voltage increase, there are methods such as discharging the power through a resistor or regenerating it into an AC RT source, but the single inverter device uses a regeneration method.

That is, as shown in FIG. 4, the transistors SU to S
The DC power supplied from the inverter 7 is converted back into AC power, which is regenerated to the AC power supply 1 side.

Therefore, in the regenerative circuit described above, only the reactor 2 limits the magnitude of the regenerative current while the transistors 5U-8Z are conductive.

Either provide a separate internal flow control or turn on/off transistors SU to SZ in shorter cycles during the above four-day period.
It was controlled off and the average current was adjusted to 14 times.

In this case, the method of controlling the current by setting the conduction period to 1200 degrees is better than the method of controlling the current by 180 degrees.

1 element with the same 14c current rating! i! Since the regenerative H voltage decreases even if the regenerative power is used, the regenerative current is set to 78 times at 180°, and each phase is independently on/off controlled so that the regenerative current flowing through the reactor 2 is consistent with the wide flow command.

[Problem that the invention seeks to solve]

By the way, when each phase is independently controlled on/off with 180° conduction, there is a problem in that a short circuit is formed between the lines and the regeneration efficiency is reduced, as shown in FIG.

This problem will be explained below, taking as an example the case where the phase voltage U is the highest and the phase voltage W is the lowest. In this case, Fig. 5 (a), (
As shown in (b), if the transistor SU or Sz is conductive, these transistors are connected to the diode DU.
, while keeping the pressure at both ends of DZ almost 0, while diode D
Reverse bias V, DW or DX, DY. Therefore,
These diodes act as cut-offs, and the positive RF 5 is disconnected from the AC power supply 1, so that no short circuit occurs in the power supply.

However, as shown in Figure 5 (C), during the 180° quadruple ON/OFF control AI for each phase independently, there also occurs a period in which the transistors SU and Sz are OFF and Sv is ON, and at this time, The diode υU and the transistor SV are in a four-way state, resulting in the formation of a kick short circuit. As a result, there is a problem in that the regeneration period is reduced and the utilization efficiency of the regeneration circuit is reduced.

This invention attempts to solve the above problems.

[Flat membrane to solve intercalation points]

In order to solve the above problems, the present invention configures the reverse RF for regeneration with a self-extinguishing element, and out of the 180° width of each phase voltage, Ml
The self-extinguishing element is controlled on/off to control the current, while the self-extinguishing element is kept in the ignited state from 60' to 12o0.

[For production]

According to the above method, during the 60 degrees before and after the instantaneous value of the valley-phase ugly pressure reaches its maximum, and during the 60 degrees before and after the lowest fore-shudder (i.e., between upper jC6o0 and 12o0), this phase is The connected self-extinguishing element is turned on.

As a result, the self-extinguishing elements related to the phase voltage with the largest absolute value are turned on one after another, and the self-extinguishing elements that have been turned on are connected to diodes (for example, the transistor SU in FIG. is on, the diodes 1) U to 1) W) connected to it are all cutoff 7 (in the above example, diode DU is zero bias, 1) V, DW
becomes a play bias and becomes a cutoff). Therefore, diodes DU to DZ7)x (positive)1. F is disconnected from the AC power source, and no short circuit occurs between the edges of AC # and the power source. In addition, during periods 11j of steam angles of 0° to 60° and 120° to 1800°, the self-extinguishing element is controlled on/off so that the flow waveform of 11 is as instructed, so that the two-phase current is always Since the current of the remaining phases that are controlled and all ignited is the sum of the currents of the above two phases,
Current control of N stations and 3 phases can be performed.

[Practical example]

Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the final configuration of the cylindrical part of the embodiment in which the present invention is applied to the current source inverter shown in FIG.
Components corresponding to those in the figure are given the same reference numerals.

This embodiment differs from the conventional device shown in FIG. 3 in the configuration of a control circuit 10a, and FIG. 1 shows a square circuit of a transistor 8U. No, other transistor 5V
A similar control pass circuit is also connected to -8Z.

In this figure, lla to IIC are current commands for each phase, which use inverted waveforms of phase voltages U, V, and xv. Comparators 12a to 12C output a rectangular signal that is at 101"H" level during the 180° period of the positive side of each phase IEU-W, and the outputs of the comparators 12b and 12C are supplied to the OR gate 13, and A signal S1 shown in FIG. 2 is formed.

On the other hand, biased 7! The output of detection point 9, that is, the U-phase voltage υ1
The current obtained by subtracting the actual current of the U phase from the current command is inverted by the inverter 14, resulting in a signal S2 shown in Figure 42 (/-1).This signal S2 is 81.h'' level and is supplied to the Nant gate 15 together with the signal S1.
Both or one of SZ outputs a signal S4 having a 1H level, which is seven times the 1L level. And comparator 12
a output signal 83 (in Fig. 2)) and the above-mentioned No. 1g S4 (
The same figure (E)) is supplied to the AND gate 16, and the same figure (E)) is supplied to the AND gate 16.
A signal S5 shown in (f) is generated.

This signal S5 is at a high level when the actual current is smaller than the current command between 0° and 60° and between 120° and 1800 out of 180° of the positive Gel of the U phase (see Figure 2). ), the "H" level is maintained throughout the period from 60' to 1200 (19 in the figure).

Therefore, the signal S5 passes through the amplifier 17 to the transistor S
When attached to the base of U, the above 00 to 60' and 1
From 20° to 1800°, the transistor SU is controlled on/off to perform current control to 1, and from 60° to 1200°, the transistor 8U is kept on. In addition, the transistors SV to SZ in the circuit are similarly controlled by the control signals shown in FIG. 2 (1) to (1).

According to the above configuration, as shown in culvert 2, the U phase IW, I
Between 00 and 60 degrees of f, transistor SY is on (all firing), SU and SW are on/off control, 600 to 1200
During this period, transistor SU is fully turned on and SY.

SZ is on/off control, transistor SZ is full firing between 1200° and 180°, 8U and SV are on/off control.
be done. Here, for example, during 60' when the transistor SU is fully turned on, the current flowing in the va and W phases is independently controlled so that it matches the current command by turning on/off the transistors SY and SZ. controlled. Further, at this time, the current flowing in the U phase is the same as the current flowing in the ■ phase and the W phase, so three-phase current control is performed after all. This also applies when the other transistors are in full firing mode.

Moreover, between the above 60° and 120′, the transistor SU
is on, and since the U-phase voltage is -#f, all diodes DU-1)W are cut off, and the positive RF5 is disconnected from the AC power supply 1.

As a result, the formation of a power supply short circuit as shown in FIG. 5 (/→) can be prevented.

In the above embodiment, the reverse B and F4 are constructed of transistors 8U to 8Z, but the present invention is not limited thereto, and any self-extinguishing element such as G'rO can be similarly used.

〔Effect of the invention〕

As explained above, the present invention provides (b) main reverse RF
of the 180° width of each phase's frame pressure, the self-arc extinguishing element is controlled on/off between θ°~60° and 1206°~180° to control the current. While doing
Since the self-extinguishing element is held in the ignition state between 60° and 120°, the following effects can be achieved.

(1) % power regeneration can be performed efficiently because power supply short circuits do not occur.

(2) The first current fjIIJ t41 can be performed using only the control circuit, and there is no need to add another current control circuit. In addition, the regeneration first flow has a width of 1806 degrees, which has a larger regeneration ability than a width of 120 degrees.

[Brief explanation of the drawing]

@ Figure 1 is a block diagram showing the configuration of main parts of an embodiment applied to the 7i-1 flow type inverter device of the present invention, Figure 2 is a waveform diagram showing waveforms of each part of the same embodiment, and Figure 3 is a conventional diagram. Figure 4 is a block diagram showing the configuration of a current source inverter device.
8Z on/off? FIG. 5, which is a diagram showing the relationship between f+lJ, is a diagram for explaining the reason why a short circuit occurs. 1...3-phase AC quenching source, 4...Reverse R・upper゛(reverse 111!l residual flow device) 5.......positive l(・F(
positive side rectifier), DU-DZ...diode, S[
J-8Z...Transistor (self-extinguishing element).

Claims (1)

[Claims] A three-phase bridge is constructed by an anti-parallel circuit of a diode and a self-extinguishing element, and this three-phase bridge is connected to the output end of a three-phase AC power supply, and during power running, the positive side rectifier consisting of the diode is operated. While supplying DC power to the load side,
In a power regeneration circuit that operates a reverse rectifier made of the self-arc-extinguishing element during regeneration to regenerate feedback power to the AC power supply, the power regeneration circuit includes:
A method for controlling a power regeneration circuit, characterized in that current control is performed between 0° and 60° and between 120° and 180°, and full ignition is performed between 60° and 120°.