JPS61109452A - Ignition control system of power converter - Google Patents

Abstract

PURPOSE:To carry out prompt protection eliminating delay time between detecting abnormal conditions and protecting action, by supervising the abnormal conditions of digital operation control means with protecting phase against a power converter, and by switching over the conditions to protecting ignition pulse at the time of detecting the abnormal conditions. CONSTITUTION:The first phase for specified control of a power converter 3 and the second phase for protection are operated by a digital operation controller 5, and in normal conditions, ignition pulse is provided for the power converter 3 according to the first phase. In the meantime, at an accident-detecting circuit 6, the abnormal conditions of the digital operation controller 5 are supervised with the second phase, and protecting ignition pulse is produced according to the operation result on the normal conditions of the digital operation controller 5. When the abnormal conditions of the digital operation controller 5 are detected, the pulse of the controller 5 is locked by a pulse-converting circuit 7, and the protecting ignition pulse is provided for the power converter 3.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is directed to controlling the phase of a firing pulse to be applied to each switching element of a power conversion device by a microcomputer (
Hereinafter, it is also referred to as a microcomputer. ) This invention relates to an ignition control method for a power converter that is controlled using a digital arithmetic and control device such as the above.

[Conventional technology]

FIG. 3 is a block diagram schematically showing a conventional example of a power conversion device equipped with a current control system. In the figure, l is a firing angle regulator that outputs a firing pulse (a), and 2 is a current command value (d
) and the current feedback amount (detected value; b) to find the firing angle command value (c).
The firing angle regulator 1 controls the firing of each phase switching element of the power conversion bag W3 based on the output C of the current regulator 2, and controls the voltage or current. It is something. Conventionally, such control systems have been constructed exclusively of analog circuits, but recently, various systems using digital arithmetic devices such as microcomputers have begun to appear. There are some examples in which the ignition pulses are controlled by a microcomputer, but one of the important things when controlling a power conversion device is protection in the event of an abnormality.

In particular, when using a digital arithmetic and control device such as a microcomputer, there is no problem as long as the arithmetic and control device is operating normally.
If the device itself becomes defective, the program runs out of control, etc., all functions may stop. For this reason, a control method is provided in which a circuit that detects an abnormality in the microcomputer and a protective ignition pulse generation circuit are provided as protection in the event of an abnormality, and when an abnormality is detected, the circuit is switched to the protective ignition pulse generation circuit side. is possible.

[Problem that the invention seeks to solve]

However, in the above method, the abnormality detection circuit and the protective ignition pulse generation circuit must be prepared completely separately, and this ignition pulse generation circuit has all the necessary functions to generate the ignition pulse. Since the device must be equipped with various functions, there is a problem in that the device becomes large and costly. In addition, since sampling for abnormality detection is performed asynchronously with respect to the power supply of the power converter, a long (delay) time occurs between detecting an abnormality and reaching the ignition phase for protection. , there is also the problem of not being able to respond quickly.

[Means and effects for solving the problem] This invention monitors abnormalities in the microcomputer using a phase that works to protect the power converter when a digital arithmetic control device such as a microcomputer controls the ignition pulse of the power converter. (sampling) and a protective ignition pulse generator that detects the phase that works for protection from the normal calculation results of the digital calculation unit (microcomputer) and generates a protective ignition pulse. When detected, the ignition pulse from the microcomputer is locked and switched to a protection ignition pulse to quickly protect the power converter.

〔Example〕

FIG. 1 is a block diagram showing an embodiment of the present invention.

In the figure, 5 is a digital arithmetic and control device, 6 is a failure (abnormality) detection circuit, and 7 is a pulse switching circuit, and the other parts are the same as in FIG. 3.

The digital arithmetic unit 5 performs a predetermined current adjustment calculation based on the current command value d and the detected current value, adjusts the firing angle in accordance with the output thereof, and outputs a firing pulse signal f. This ignition pulse signal f is applied to the power converter 3 through a pulse switching circuit 7 as an ignition pulse a. Failure detection circuit 6
receives data i representing the time until detecting an abnormality from the digital arithmetic unit 5. This data 1 is updated to a new value every time the digital arithmetic and control unit 5 generates the ignition pulse signal f. For example, now the firing angle α is α, = 85° ej! Suppose that the ignition pulse is output at an angle or position (degrees; electrical angle), at that point the digital arithmetic unit 5 calculates, for example, the time until the phase in which the current is reduced to zero, that is, the phase α1hllX in which the power converter works for protection. Δα is calculated and given to the abnormality detection circuit 6 as data i. Here, if αlI□-150 degrees, then Δα=60+α11. X-α1-60+150-85=125 (degrees).

・And if the calculation unit N5 is normal and operating correctly,
The next ignition pulse is output before the time Δα required to reach the phase that protects the converter has elapsed, and a new Δα is calculated and set at that point, so that the abnormality detection circuit 6 The output signal will never become active because the time set in but,
If the digital arithmetic unit becomes abnormal and cannot output the next ignition pulse after outputting the ignition pulse and setting Δα before outputting the next ignition pulse, the previously set Δα At the point in time (corresponding to time αIIIIX), the output of the abnormality detection circuit 6 becomes active, outputs the ignition pulse signal g to the pulse switching circuit 7, and outputs the pulse switching signal ri, and the ignition pulse a Then, the output f of the digital arithmetic unit 5 is switched to the abnormality detection circuit output signal g, and the ignition pulse a is incremented by 4 for the power conversion device 3 at times α and □. The abnormality detection circuit 6 is given the amount of data corresponding to this Δα and a value equivalent to 60 degrees, and after Δα is timed up, a programmable timer repeats the tie J amplifier at time intervals equivalent to 60 degrees. It has a function. FIG. 1A is a block diagram showing a specific example of the abnormality detection circuit 6. In the figure, 61 is a counter that determines which phase the firing pulse is distributed to, 62 is a programmable timer, 63 is a waveform shaping circuit that converts this timer output into the firing pulse width, and 64 is a counter that determines which phase the firing pulse is distributed to. , a waveform shaping circuit for generating a pulse switching signal to be outputted to the pulse switching circuit 7, and 65 is an AND circuit. The signal j is a signal from the pulse switching circuit 7, which is input every time the firing pulse a is output, and serves as a clock for the firing phase counter 61. The firing phase signal β, which is the output of the firing phase counter 61, is
Next, it represents the phase in which the ignition pulse should be output. AND
The gate 65 is a timer 62 whose waveform is shaped by the circuit 63.
It has a function of distributing the output k of as the corresponding ignition phase pulse. FIG. 2 is a timing waveform diagram for explaining the operation of FIG. 1 or FIG. 1A.

Now, for example, when a W-phase ignition pulse is output as shown in FIG. 2(b), the arithmetic and control unit 5 in FIG. If the microcomputer 5 is operating normally, the ignition pulse of the Y phase, which is the next phase after the W phase in the phase order, is output as shown in the same figure (c).
Δα3 is newly calculated, and the result of this calculation is sent to the timer 62. Therefore, the previously set Δα2
time will be reset. Therefore, the output of the timer 62 becomes as shown by the dotted line in FIG. 2 (e) and is not active. After this, for example, if the microcomputer becomes abnormal at time t, the timer 62, which has been set for a time of Δα3, cannot be reset, so after the elapse of this Δα, the output k of the timer 62 becomes as shown in FIG. 2 (E). It becomes active and an ignition pulse is output to the phase indicated by the phase counter 61. At this time, the output signal f from the digital arithmetic unit (microcomputer) 5 is locked by the waveform-shaped signal of the counter output k.

Therefore, a pulse is output at time α11, and thereafter, an ignition pulse of αIIIX is supplied to each phase. Note that FIG. 2(a) shows an example of the output waveform of the power conversion device.

〔Effect of the invention〕

According to this invention, abnormalities in the digital arithmetic and control device (microcomputer) are monitored (sampled) in synchronization with the ignition phase that protects the power conversion device, while the arithmetic results when the digital arithmetic and control device is normal are monitored (sampled). The protection firing pulse phase (this is also the abnormality detection sampling point) is detected based on Since the power is supplied to the power converter, the protective ignition pulse output circuit can be realized with a simple hardware configuration (no synchronization signal circuit is required), and there is no dead time between detection and protection operation. , the effect of enabling quick response is brought about.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the present invention, FIG. 1A is a block diagram showing a specific example of the failure detection circuit of FIG. 1, and FIG. 2 is a timing waveform diagram for explaining the present invention in detail. Third
The figure is a schematic configuration diagram showing a conventional example of a power conversion device having a current control system. Symbol explanation 1... Firing angle regulator, 2... Current regulator (ACR)
, 3... Power conversion device, 4... Load, 5... Digital arithmetic control device, 6... Failure detection circuit, 7...
Pulse switching circuit, 61-=counter, 62... timer, 63.64... waveform shaping circuit, 65... AND gate. Agent Patent Attorney Akio Namiki Agent Patent Attorney Kiyoshi Matsuzaki Figure 1'f'1g''1 Figure 2

Claims (1)

[Claims] A digital device that calculates the phase of the ignition pulse to be given to each switching element of the power conversion device for performing predetermined control (first phase) and for protecting the power conversion device (second phase). A control system that includes arithmetic control means and performs ignition control of the power conversion device mainly based on the first phase during normal operation, and constantly monitors the second phase and detects abnormality in the arithmetic control means from the monitoring results. and a pulse generating means that generates a protective ignition pulse from the detection output, and when the detecting means detects an abnormality in the arithmetic control means, the protective point from the pulse generating means is An ignition control method for a power converter, characterized in that the power converter is controlled by arc pulses.