JPH06508500A - Power conversion circuit with intermediate circuit monitor - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Power conversion circuit with intermediate circuit monitor Conventional technology The invention starts from a device according to the preamble of claim 1. This kind of device , is known from West German Patent Application No. 3113909. The equipment listed there According to FIG. It has an inverter 13 that is powered by. Stabilizes intermediate circuit DC voltage A capacitor is provided for this purpose. The power rectifier is advantageously uncontrolled It is of type. Control of the inverter is performed by a common logic circuit 20. , the motors powered by the inverter all rotate by the same number of revolutions . Each inverter has a corresponding number of individual drive motors. It only supplies power. From this publication, multiple inverters each have their own control logic circuit. Proposals for providing channels are also known. This publication further states that in the event of a supply current interruption, the individual drives Based on the coasting characteristics of the energy is passed through the intermediate circuit, but still all drive 10 shows that the parts are shifted to stop at approximately the same point in time.

For active regulation of the intermediate circuit DC voltage and/or characteristics of the individual drives The means for improving this are not clear from this publication. But from the same intermediate circuit When the inverters to be supplied operate independently of each other (e.g. in servo drives) (as in the case of and cause voltage fluctuations there. Furthermore, such voltage fluctuations may affect the operation of the drive section. It has an unfavorable effect on the dynamic characteristics.

The problem of the invention is to provide the same medium that allows optimization of the operating characteristics of the drive and the rectifier. By providing a power conversion circuit having multiple inverters fed from a circuit between be.

This object is solved by a device having the features according to the characterizing part of claim 1. . The power conversion circuit of the present invention stabilizes the intermediate circuit DC voltage and at the same time makes it possible to match the operating state of each section to the current intermediate circuit DC voltage. , has a device for stabilizing the overall operating characteristics. Power requirements of individual drives At the same time, accurate control of intermediate circuit DC voltage is possible by continuously detecting It is. At the same time, the current intermediate circuit DC current is continuously applied to each drive unit. I can understand the pressure. This makes it possible to improve the operating characteristics of the individual drives. present invention The configuration of the power converter circuit is simple and it essentially requires one additional signal line. Contains. The complicated measurement of the intermediate circuit DC voltage is only required once, and at the same time Improved voltage control reduces the smoothing capacitance in the intermediate circuit. It can be chosen relatively small, which has advantages in terms of costs.

By considering only the drive part with a large value of power change per unit time, , control of the individual drives with good results is advantageous since the required or delivered In any case, the power output is adjusted to the instantaneous energy delivery or input capacity of the intermediate circuit. It is done in such a way that it matches.

Next, the present invention will be explained in detail based on the drawings.

The figure is a basic circuit diagram of the device of the present invention.

The block diagram of the power converter circuit shown is functionally divided into two main parts. . That is, a power circuit having elements designated 10 to 13 and 14 to A control circuit 40 having elements indicated at 30.

The construction of the power circuit is known per se. Its input side typically receives three-phase AC power from the power distribution network. The output side of the rectifier 11 to which current is applied forms a DC voltage intermediate circuit 10 . this The circuit powers a plurality of inverters 12 with DC voltage. each inverter 12 In the case of Supply power. The important components of inverter 12 are It is a power transistor. Each two of them is equal to 1 of the output current on the drive side. It generates two phases. The control is carried out by control units installed correspondingly. 14 according to a pulse width modulation method. Inverter installation of the above type The device is provided, for example, in a multi-axis, numerically controlled machine tool.

The second main part of the power conversion circuit of the present invention is the control circuit 40. For that, here is an inverter control unit 14, a grid rectifier control unit 15, and an intermediate circuit. a direct voltage source 21 with an associated measuring device 23 in the circuit and also an inverter controller; control unit 14, rectifier control unit 15 and main control unit not shown here. A line device 30 arranged between the control parts and, in particular, parallel to the power circuit concerned, A signal line 20 is arranged regardless of the potential of the intercircuit. This belief The roadway is extremely important to the invention. It is possible to reduce the DC voltage source 21 to a small value (also Connected in series to one inverter control unit 14 as well as rectifier control unit 15 do. Next, the individual components of the control circuit will be explained in detail.

The main components of the inverter control unit 1 connected to the signal line 20 are a control module 16, a controllable current source 22, and a voltage measuring device 24.

Current source 22 and voltage measuring device 24 allow inverter control unit 14 to The signal line 21 is physically coupled to the signal line 21. However, all existing inverters 12 are trusted. Needless to say, connecting to the road 20 is not necessarily necessary. depending on the case In the inverter control unit 14 that is not connected to the signal line 20, the current source 22 and/or voltage measuring device 24 can be omitted. inverter control All components of unit 14 are connected to appropriate signal lines according to the pattern shown. are interconnected via channels.

The task of the control module 16 is to process the incoming signals as well as to control the power output of the inverter. This is control of the transistor and current source 22. one or more data or signals Via a line arrangement 30 consisting of a line, the control module 16 can control another inverter. It communicates with unit 14 as well as rectifier unit 15. Furthermore, via the track device 30 a central control unit (not shown), e.g. the main control of a numerically controlled machine; Data is exchanged with In other words, each inverter control unit is controlled from this main control section. In step 14, operating target values such as power target value, acceleration target value, deceleration target value, etc. is supplied. The current source 22 and the voltage measuring device 24 measure the inverter control unit. Knit 14 is coupled to signal line 20.

The grid rectifier control unit 15 essentially detects the current flowing through the signal line 20. It consists of a measuring device 25 and a control module 17. This control module The role of the module 17 is to send control signals to the power semiconductors of the grid rectifier 11 and to is to adjust the circuit voltage between. For this purpose, the measuring device 25 must be equipped with a corresponding Process the signals supplied via the connection. Through the data line 30, the rectifier control The control unit 15 is connected to the inverter control unit 14 and the main control section. .

The voltage source 21 is connected via suitable lines to a voltage measuring circuit arranged in the intermediate circuit 1°. It is connected to road 23. In this connection configuration, the grid rectifier control unit connection arrangement between the grid rectifier 11 and the inverter control unit 14 and the inverter 12, which are not shown in detail here. , a device is provided for separating the potentials of the signal line 20 and the intermediate circuit 1o. Ru. The signal line 2o can advantageously be used simultaneously as a ground for further signals. associated with the ground line.

The physical realization of the device shown is advantageous in that the drive 13 is spaced apart in a common frame. It is carried out in the form of modules that are housed separately. First module type In the formula, only one component is provided in each power conversion circuit. , a power grid rectifier 11, a rectifier control unit 15, a voltage source 21 and a voltage measuring device. 23 are summarized. separate, usually multiple, respective drives In the module format provided corresponding to 13, each inverter 12 and a corresponding inverter control unit 14 are arranged.

In the device described so far, the voltage measuring device 23, which functions as follows, has an intermediate circuit. Detect the current voltage on line 1o and separate the measured value electrically and send it to voltage source 21. Transmit. A voltage source is connected to the signal line 2o as a measure for the measured intermediate circuit voltage. Apply the DC voltage UM. At that time, the voltage UM of the signal line 2o becomes the intermediate circuit voltage. Continuously controlled to the corresponding value. For this purpose, the voltage source 21 is with voltage setting adjustment or control equipment not shown. This form of voltage source is As such, for example “Halbleitershaltungstechnik” , Tietze, 5chenk, 7th edition, paragraph 1, 13.2.

Advantageously, the voltage applied to the signal line 2o is measured, for example in the intermediate circuit 1o. so that the voltage of 6V corresponds to the voltage of 600μ on the signal line 20, It is advantageous to shift in the low voltage range from 0 to IOV.

At the same time, the signal line 2° to which the DC voltage is applied from the voltage source 21 is connected to the voltage source 21. Regardless, the inverter control unit 14 uses the current source 22 present therein. In each case, a current corresponding to the instantaneous target power of the correspondingly provided drive 13 1. ,．． 1. □,...+ Supply one of the IANs.

For this purpose, for example, "Halblei tershaltungstechni" K”, Tietze, 5chenk, 7th edition, paragraph 1 paragraph 4.6.2. Any conventional current source can be used.

Each control unit 14 measures the voltage UM applied to the signal line 20. It has the following equipment. The instantaneous intermediate circuit voltage measured using the measuring instrument [24] The corresponding voltage value UM is supplied to the control module 16. The control module is The measured value is calculated as the pulse duration for the power semiconductors in the inverter 12. Relate to decisions.

Based on the information regarding the intermediate circuit voltage, the operating characteristics of the individual drive units 13 are modified multiple times. be good. That is, the control module 16 ensures that the voltage applied to the associated drive 13 is It can be guaranteed that the required target value is met.

For example, the control module 16 may be configured such that it Based on the fact that the voltage actually applied to the intermediate circuit is predetermined with respect to the intermediate circuit voltage. When the pulse duration is detected to be below the set target value, the pulse duration is extended.

Without this type of correction, the pulse duration is related to a predetermined intermediate circuit target value. Although accurate, too low a voltage is applied to the drive. signal By knowing the intermediate circuit voltage from the line voltage, the control monoyl 17 can further control the acceleration process. can be performed in accordance with the current energy delivery/input amount of the intermediate circuit. . In the event of a power outage (power outage), the “large” drive unit that is used as a generator at that time By the desired deceleration, the voltage in the intermediate circuit is connected to the same intermediate circuit. can now be maintained until another drive is brought into safe operating condition. Ru.

Each inverter control unit 14 of the signal line 20 A current IAI corresponding to the power input to the drive unit 13 or sent out from the drive unit corresponds to The information contained in the current of the entire signal line is transmitted in the intermediate circuit 10. Used to adjust voltage. For this purpose, the rectifier control unit 15 The control unit has a measuring device 25 using which the control unit determines the total current flowing through the signal line 20. Detect the current value of field I. Measured value corresponding to input/output power is supplied to the control module 17 and there counts control pulses for the rectifier 11. associated with calculation. It is particularly suitable for regulation according to the pre-control principle.

In this adjustment method, the rectifier control unit 15 receives the input or It responds directly to the respective changes in the delivered power.

The proposed device reduces power consumption per unit time compared to other drives. Only the drive unit 13 uses the current source 22 to send a current corresponding to the current power to the signal line. 20, a useful stabilizing adjustment of the intermediate circuit voltage is possible. Conversely, Drives with small time-related power changes do not necessarily need to be connected to the signal line. There's no need.

If the requirements for the overall operating characteristics of the power conversion circuit are not very high, the signal line 2 0 to the intermediate circuit DC voltage to the drive unit and the signal from the drive unit It is only possible to improve the regulation of the intermediate circuit DC voltage based on the current supplied to the line 20. It is enough. In this case, a fixed, predetermined DC voltage is applied to the signal line. easily supplied. At that time, the voltage measuring device 124 and the inverter control unit 1 4 can be omitted.

The proposed power conversion circuit instantly inputs all inverters 12 to the signal line. supplying a current corresponding to the transmitted/transmitted power, and transmitting this current to the distribution network controller 15. is measured and the voltage source 21 applies a voltage to the signal circuit 20, which is in turn inverted. It is based on the principle that the data control unit 14 measures. maintain this principle If so, the above-described power conversion circuit device can be modified. That is, for example, an inverter Replace the power transistor in No. 12 with another element that performs the same function. or perform a different division from the proposed configuration division of the functional circuit unit. be able to.

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Claims (9)

[Claims] 1. Where the DC voltage output side supplies a substantially constant DC voltage to the intermediate circuit. a power rectifier with an associated control unit and a power supply rectifier each supplying one or more motors; multiple inverters, each with its own control unit. In the power conversion circuit equipped with The control unit (15) of the power rectifier (11) and the inverter (1 2), a signal is sent to the control unit (14) for controlling the intermediate circuit DC voltage. A signal line (20) is arranged to transmit the motor. A current corresponding to the individual power required by or generated by said motor ( A power conversion circuit characterized in that it is configured to lead I■). 2. At least one inverter control unit (14) is connected to the signal line (20). ), the current source (22) being arranged within the signal line (20). the instantaneous power required by or delivered by the associated drive (13); 1 . . . , IAN). The power conversion circuit described. 3. The rectifier control unit (15) includes a control module (17) as well as a signal line ( 20), the current measuring device (25) being located at the The entire current (I■) flowing through the signal line (20) is detected and the control module (17 ).The power conversion circuit according to claim 1 or 2, wherein the power conversion circuit transmits data to a power converter circuit according to claim 1. 4. A voltage source (21) is provided corresponding to the signal line (20), and the voltage source is applying a voltage (UM) corresponding to the instantaneous intermediate circuit voltage to the signal line (20); The power conversion circuit according to any one of claims 1 to 3. 5. At least one inverter control unit (14) receives an inverter control signal. a control module (16) and a voltage measuring device (24) for generating; The voltage measuring device detects the instantaneous voltage (UM) value on the signal line (20). and transmitting to the control module (16) any one of claims 1 to 4. The power conversion circuit described in section. 6. Claims 1 to 5, wherein the reference potential of the signal line (20) is connected to ground. The power conversion circuit according to any one of . 7. A voltage measuring device (23) is provided corresponding to the DC voltage intermediate circuit (10). The voltage measuring device measures the intermediate circuit voltage and separates the measured value electrically. Any one of claims 1 to 6, transmitting to the voltage source (21) of the line (20). The power conversion circuit described in section. 8. Claims 1 to 7, characterized in that the adjustment of the intermediate circuit DC voltage is carried out by preliminary control. The power conversion circuit according to any one of the following. 9. Only the drive unit (13) that has a large power change per unit time is Current corresponding to the input/output power (IA1, IA2,..., IAN ) is supplied to the signal line (20). Force conversion circuit.