JPS63171159A - Control monitor of power converter - Google Patents

Abstract

PURPOSE:To fit with an economic device, by transmitting through electric wires control monitoring signals between a main circuit panel and a control panel or a control circuit. CONSTITUTION:In a control monitoring device such as an inverter, etc., a main circuit panel 100A is equipped with GTO thyristers 1-4 and gate circuits 5-8. Element monitoring circuits 9-12 are also provided respectively to monitor the operation of each element. The operation of these gate circuits 5-8 is controlled by ON-OFF signals (a) outputted from a control circuit 13 in a control panel 200A provided off the main circuit panel 100A. Monitoring signals (b) are sent out to the control circuit 13. On this occasion, a signal repeater 14 is provided in the main circuit panel 100 A. Each signal (a) and (b) is sent and received, by connecting this repeater 14 and the control circuit 13 with electric wires 300a and 300b, and the repeater 14 and gate circuits 5-8 as well as monitoring circuits 9-12 with light guides 15a and 15b. The device can thereby be made inexpensive and highly reliable.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention relates to a main circuit board equipped with a power converter such as an inverter, and a control signal for controlling firing control signals and element monitoring signals for semiconductor switching elements constituting the power converter. The present invention relates to a control and monitoring device for a power converter, which includes an external control circuit that transmits and receives information.

(Prior Art) Conventionally, as this type of control and monitoring device, one shown in FIG. 3, for example, is known. That is, in the figure] 00 is a main circuit board constituting an inverter as a power converter, and within this main circuit board 100, GTO thyristors 1 to 4 as self-extinguishing semiconductor switching elements are connected in series. Of these, 6To thyristors 1 and 2 constitute a lower arm, and 6To thyristors 3 and 4 constitute a lower arm, respectively. Note that, for convenience, only one phase of GTO thyristors 1 to 4 is shown here.

Furthermore, gate circuits 5 to 8 are provided corresponding to these GTO thyristors 1 to 4, and element monitoring circuits 9 to 12 for monitoring the operation of each element are provided, respectively.

Here, the operation of the gate circuits 5 to 8 is controlled by an on/off command signal a output from a control circuit 13 in a control panel 200 installed a certain distance ahead of the main circuit board 100. , element monitoring circuits 9 to 12 are GTO
The operating state of the thyristors 1 to 4 is monitored and a monitoring signal thereof is sent to the control circuit 13.

Therefore, a control signal (on/off command signal) a is transmitted between the main circuit board 100 and the control board 200, which handle large amounts of power.
When transmitting and receiving the element monitoring signal, a transmission method has been adopted in which a light guide (optical cable) 300 is used to connect the two in consideration of insulation, and each signal a and b is transmitted and received as an optical signal.

(Problem to be Solved by the Invention) However, in such a control and monitoring device, twice as many relatively expensive light guides 300 as the total number of semiconductor switch elements are prepared, and these light guides 300 are connected to the main circuit board 1.
00 and the control panel 200 over several tens of meters. For this reason, there is a problem that the cost becomes enormous and that when installing the light guide 300 outside the panel, sufficient care must be taken to prevent twisting, bending, etc. of the light guide 300.

The present invention was proposed to solve the above problems, and its purpose is to enable control monitoring signals to be sent and received between the main circuit board and the control board at low cost and with high reliability. An object of the present invention is to provide a control and monitoring device for a power converter.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a main circuit board with a power converter such as an inverter in which upper and lower arms are configured by connecting semiconductor switching elements such as GTO thyristors in series. A control and monitoring device for a power converter that transmits and receives an ignition control signal and an element monitoring signal for the semiconductor switch element to and from a control circuit provided outside the main circuit board, wherein the main circuit board includes a power converter. A signal repeater is provided for transmitting and receiving the ignition control signal and the element monitoring signal to and from the device side using an optical signal, and the signal repeater and the control circuit are used as a transmission path for the ignition control signal and the element monitoring signal. It is characterized by being connected via electric wires.

Further, the signal repeater is configured to generate the ON command signal based on an AND condition of the OFF confirmation signal of the semiconductor switch element of one of the upper and lower arms of the power converter and the ON command signal of the semiconductor switch element of the other arm. It is desirable to include an AND circuit that outputs the value to the semiconductor switch element of the other arm.

(Function) In the present invention, an ignition control signal from an external control circuit is input to a signal repeater in the main circuit board via an electric wire, and the signal repeater converts it into an optical signal and inputs it to the power converter side. be done. Further, the element monitoring signal of the semiconductor switch element is input as an optical signal to a signal repeater, and after being converted into an electrical signal in the signal repeater, the signal is sent to a control circuit via an electric wire.

In addition, short circuits between the upper and lower arms of the power converter are prevented by interlock means provided in the signal repeater as necessary.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

Figure 1' shows an inverter control device to which the present invention is applied for one phase thereof, and similarly to the above,
4 is a GTO thyristor (hereinafter simply referred to as a thyristor) as a self-extinguishing semiconductor switching element; 5 to 8 are gate circuits; and 9 to 12 are element monitoring circuits. Main circuit board 10
A signal repeater 14 for one phase of the inverter is provided in 0A, and the signal repeater 4 and the control circuit 13 in the control panel 200A are connected by electric wires 300a and 300b. Here, the electric wire 300a is the thyristor 1
The electric wire 300b is used for transmitting the on/off command signal as the ignition control signal of 4 to 4, and the electric wire 300b is used for transmitting the element monitoring signal.

Furthermore, the signal repeater 14, the gate circuits 5 to 8, and the element monitoring circuits 9 to 12 are connected by light guides i5a and 15b, respectively, and each signal is exchanged between them by optical signals to ensure insulation. It has become.

Next, the internal configuration of the signal repeater 14 will be explained based on FIG. 2. This signal repeater 14 is equipped with an interlock function to prevent a short circuit between the upper and lower arms for one phase of the inverter. For example, when commutation is performed between the upper and lower arms, the interlock function prevents the upper arm from shorting. This function enables the ON command signal from the control circuit 13 to the lower arm at the time when the signal repeater 14 receives the OFF confirmation signal from the element monitoring circuits 9 and 10 when the constituent thyristors 1 and 2 are turned OFF. be.

That is, the configuration includes an on-delay circuit 16 connected to the electric wire 300a, an on-delay circuit 18 also connected via the negative circuit 17, and each on-delay circuit 16.
．． AND circuits 19 and 20 for interlock provided on the output side of 18, and signal converters 21 to 21 that convert the output signals of these AND circuits 19 and 20 into optical signals and send them to gate circuits 5 to 8, respectively. 24 and element monitoring circuits 9 to 1
The optical signal from 29.2 is converted into an electrical signal and the AND circuit 29.
The output signals of the signal converters 25 to 28 and the AND circuits 29 and 30 respectively input to the wire 300 are encoded and output to the wire 300.
It consists of an encoder 31 that sends data to b.

Note that the output signals of AND circuits 29 and 30 are respectively applied to the other input terminal of AND circuits 20 and 19. In addition, the symbol E/ in the figure in the signal converters 21 to 28 is
○ indicates conversion from an electrical signal to an optical signal, and O/E indicates conversion from an optical signal to an electrical signal. Furthermore,
When the output signal from the AND circuit 19.20 is "1", it issues an ON command to the thyristors 1 to 4, and each signal converter 25 to 2
8 indicates that the corresponding element monitoring circuits 9 to 12 are thyristors 1 to 4.
When it is confirmed that the switch is off, it outputs "1".

This operation will be explained below. First, for example, the control circuit 13
Considering the case where an off command is given to thyristors 1 and 2 in the upper arm and an on command is given to thyristors 3 and 4 in the lower arm, the on/off command signal inputted to the signal repeater 14 at this time is "O". This signal is sent to the on-delay circuit 16
and the thyristors 1 and 2 via the signal converters 21 and 22.
are added to turn them off immediately.

On the other hand, the on/off command signal is inverted by the NOT circuit 17 to become "1" and is input to the ON delay circuit 18. This on-delay circuit 18 operates for a period longer than the turn-off time of the thyristors 1 and 2 of the opposite arm (upper arm).
It delays the ON command to the thyristors 3 and 4 of its own arm (lower arm), and the OFF command is output to the AND circuit 20 at the next stage without delay.

Then, in the AND circuit 20, an ON command is issued based on the AND condition of the ON command from the ON delay circuit 18 and the output signal of the element monitoring circuit 25, 26 or the AND circuit 29 that confirms that the thyristors 1 and 2 of the upper arm are turned off. Outputs "1". This ON command is applied to the lower arm gate circuits 7 and 8 via the signal conversion circuits 23 and 24, and is applied to the thyristors 3 and 4.
This is what turns on the world.

The above operation is substantially the same when turning on the thyristors 1 and 2 of the upper arm. According to this embodiment, it is possible to reliably prevent short circuit between the upper and lower arms during commutation, and also to control Even if an ON command is output to the thyristors 1 to 4 of both the upper and lower arms due to a malfunction of the circuit 13, a short circuit between the upper and lower arms can be prevented.

Note that the present invention is applicable not only to an inverter control circuit as in this embodiment, but also to a sirisk converter and the like.

(Effects of the Invention) As described in detail above, according to the present invention, control monitoring signals between the main circuit board and the control board or control circuit are transmitted via inexpensive and easy-to-handle electric wires, and Since the signal transmission path using the light guide is minimized, an extremely economical control device can be realized.

Further, by providing an interlock means in the signal repeater as necessary, it is possible to reliably prevent short circuits between the upper and lower arms of the power converter, thereby providing a highly reliable control device.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 2 is an internal block diagram of a signal repeater, and FIG. 3 is a block diagram showing a conventional example. 1 to 4...GTO thyristor

Claims (2)

[Claims] (1) A main circuit board is equipped with a power converter in which semiconductor switch elements are connected in series to form upper and lower arms, and an ignition control signal and an element monitoring signal for the semiconductor switch element are provided outside the main circuit board. In the control and monitoring device for a power converter that transmits and receives the ignition control signal and the element monitoring signal to and from the control circuit, the main circuit board is provided with a signal repeater that transmits and receives the ignition control signal and the element monitoring signal to and from the power converter side using optical signals. A control and monitoring device for a power converter, characterized in that the signal repeater and the control circuit are connected via an electric wire as a transmission path for the ignition control signal and the element monitoring signal. (2) The signal repeater generates the ON command signal based on the AND condition of the OFF confirmation signal of the semiconductor switch element of one of the upper and lower arms of the power converter and the ON command signal of the semiconductor switch element of the other arm. 2. The control and monitoring device for a power converter according to claim 1, further comprising means for outputting the signal to the gate circuit of the semiconductor switch element of the other arm.