JP2820142B2 - Power converter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power converter suitable for an abnormal condition occurring in a ready state of a power converter such as an inverter.

[0002]

2. Description of the Related Art A conventional apparatus is disclosed in Japanese Patent Application Laid-Open No. 61-24086.
As described in No. 0, abnormalities that occur in the ready state of the inverter are also processed. Where
The ready state will be briefly described. Generally ready
The end state means that the input power to the power converter is turned on,
A voltage is applied to a main circuit and a control circuit of the power converter,
Ready for operation immediately after the operation command is input
Completed, and also referred to as standby.
U. That is, in the example where the power converter is an inverter,
When the power supply voltage is applied from the input power supply to the inverter,
AC voltage of the power supply is DC voltage with the forward converter in the inverter.
And applied to the smoothing capacitor,
Is applied with this DC voltage. Ready letter
When no operation command is input during
Turn off the signal from the gate drive circuit that operates the converter
State so that the inverter does not start the inverse conversion operation.
Is done. At this time, the control power supply is
Is applied, and the control circuit is operating,
Since no operation command has been input, the gate drive circuit
Is kept off. At this time Invar
Immediately enters the operating state when an operation command is input.
He is said to be in a ready state to be able to. Therefore control
The circuit is in the operating state with the abnormality detection circuit.
Output an abnormality detection signal to protect the power converter.
Is in a state where the processing operation is performed. Detected by abnormality detection circuit
Is performed when an abnormal phenomenon is actually occurring.
When detecting an abnormality, for example, if the power supply voltage
Undervoltage detection, momentary power failure, or temporary power
In addition to abnormalities such as overvoltage detection due to pressure rise, external noise
Only the malfunction detection circuit of the control circuit malfunctions,
Error detection signal even though no abnormal phenomenon has occurred
May be output. And such an abnormal phenomenon
And noise malfunctions are often transient,
Many things always return. Such an abnormal phenomenon is
The transfer unit is in a standby state and is not ready for operation.
If the abnormality detection circuit detects that the
After returning to normal, there is no hindrance to shifting to the operating state.
Despite have conventionally luck and abnormality processing power conversion device
Had stopped. Conventionally, when an abnormality is detected, the protection circuit
Roads will now maintain an abnormal signal until safety is confirmed
Has been detected, the abnormality detected during this ready state
The signal continues even after operation preparation is completed, and this abnormal signal is released.
Unless otherwise, normal operation could not be entered. Obedience
For example, Japanese Patent Application No. Sho 62-59 discloses an abnormality detection circuit of the related art.
No. 640 (JP-A-63-224695).
Is the output from the protection circuit as shown in this prior art.
Is held by the latch circuit, and is affected by CPU interrupt processing.
The normal processing operation is performed, the motor control unit stops, and this stop
The state is maintained. In this conventional technology
Is the instruction of the frequency setting device by the signal of the start switch SW0.
Output corresponding ON / OFF command signals U, V, W
, The signal of the start switch SW0 is
Whether the control is ready or running
It is a signal to decide.

[0003]

In the above prior art, no consideration is given to the processing of abnormalities that occur in the ready state of the inverter device, and the abnormalities that occur in the standby state of the device are also displayed and actually used. There is a problem that the apparatus cannot be used unless a user resets the failure when operating the apparatus.

[0004] Since the conventional device latches an abnormal signal for all abnormalities, abnormalities that occur in the standby state are not detected.
Once detected by the abnormality detection circuit, the abnormality
Abnormality due to insufficient pressure, momentary power failure, power supply overvoltage, external noise
A transient abnormality such as a malfunction of the detection circuit
Even after the reset, it is maintained forever unless a reset operation or power supply is turned off. Even if such a transient abnormality occurs in the standby state, it is considered that this abnormality rarely continues until an operation command is input from the standby state to attempt to shift to the operation state. However, when the conventional inverter is operated, if an abnormality has occurred before that, the operation becomes impossible unless the abnormal latch signal is reset. That is, if an abnormality occurs when the inverter stops, even if the abnormality disappears at the time of operation for latching the inverter, the operation becomes impossible unless the latch signal is released by resetting.

[0005] It is an object of the present invention to improve the operability of the user by configuring the power converter to be in an operable state when an abnormality occurs only in the standby state of the apparatus.

[0006]

The above object is achieved by providing means for setting the power converter to an operable state when an abnormality occurs only in the standby state of the apparatus.

With the above-described means, an abnormality that occurs when the apparatus is in the ready state is prevented from being stopped due to the abnormality, so that there is no need to reset the apparatus each time the user drives the inverter apparatus.

[0008]

BRIEF DESCRIPTION OF THE DRAWINGS FIG.
This will be described with reference to FIG.

In FIG. 2, 1 is a forward converter, 2 is an inverse converter, 3 is a smoothing capacitor, and 4 is an AC machine.

Reference numeral 5 denotes a current detector, 6 denotes a power supply abnormality detection circuit, 7 denotes an overvoltage detection circuit, and 8 and 10 denote overcurrent detection circuits. 12 is a frequency commander, 11 is a control circuit,
9 is a gate drive circuit for driving a main element in the inverter.

[0011] The operation of the inverter is a known technique, and the description thereof is omitted.

FIG. 1 is a flowchart of a program for determining an abnormal process according to the present invention.

When an abnormal signal is output from each detection circuit, the routine proceeds to an abnormal processing determination routine.

At this time, it is determined whether or not the inverter is operating. If not, the inverter is automatically reset to clear all the abnormal signals. When the vehicle is in operation, the process is executed through a normal routine for performing an abnormal process.

As described above, according to the present embodiment, the microcomputer in the control circuit operates so as to constantly monitor the abnormality signal from each detection circuit and whether the inverter device is in the ready state. Since the abnormal latch signal generated when the inverter device is not in the operating state can be automatically reset, it is not necessary to reset the device each time the user drives the device, so that the operability of the user can be improved.

[0016]

According to the present invention, the power converter is in an operable state when an abnormality occurs when the inverter is not driven, so that the operability of the user can be reduced when the user drives the inverter. There is an effect that it can be improved.

[Brief description of the drawings]

FIG. 1 is a flowchart of an abnormality processing determination program.

FIG. 2 is a circuit configuration diagram of one embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Forward converter, 2 ... Inverter converter, 3 ... Smoothing capacitor, 4 ... AC machine, 5 ... Current detector, 6 ... Power supply abnormality detection circuit, 7 ... Overvoltage detection circuit, 8 ... DC overcurrent detection circuit, 9 ... drive circuit, 10 ... AC overcurrent detection circuit, 11 ... control circuit, 12 ... frequency commander.

──────────────────────────────────────────────────続 き Continued from the front page (72) Inventor Koji Kamihara 7-1-1-1 Higashi Narashino, Narashino City Inside Narashino Plant, Hitachi, Ltd. (58) Field surveyed (Int. Cl. ⁶ , DB name) H02M 7/42 -7/98 H02H 7/122

Claims (3)

(57) [Claims] 1. A power conversion device capable of converting to an arbitrary voltage and frequency, an AC machine driven by an output of the power conversion device, and abnormality detection means for detecting an abnormality when the abnormality occurs. In the apparatus, the abnormality detecting means may be different.
When the normal condition is detected, it is determined whether or not the power converter is operating.
Differentiating means for determining that the power converter is not operating
If it is determined by the determination means, the abnormality detection means
Means for resetting the normal detection signal.
Power converter. 2. An electric power conversion device capable of converting to an arbitrary voltage and frequency, and an alternating current driven by an output of the electric power conversion device.
Motor and abnormality detection to detect abnormality when abnormality occurs
In an apparatus provided with an output unit, the abnormality detection unit detects an abnormality.
When the power converter is in a standby state.
In the case, a means is provided for automatically resetting the detected abnormality.
A power converter characterized by the above-mentioned. 3. A power converter capable of converting to an arbitrary voltage and frequency, and an alternating current driven by an output of the power converter.
Motor and abnormality detection to detect abnormality when abnormality occurs
In the apparatus provided with the output means, the power converter
By the abnormality detection means detected when in the standby state
It is equipped with a means for automatically resetting the abnormality detection signal.
A device to mark.