JPH11191923A - Led display circuit for inverter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To visually judge a switching element portion where anomaly has occurred, by keeping a detection signal in holding state in an abnormal drive voltage detection circuit in a drive circuit for a switching element, by detecting and displaying the detection signal in other circuit and equipment, and by providing a built-in detection circuit for main power supply and a built-in discharge circuit for electric charge. SOLUTION: If a drive voltage being applied to the gate electrode of IGBT is deviated from the set point, an abnormal drive voltage detection circuit built, in a first control circuit operates, and based on the result, a first abnormal signal holding circuit as a holding circuit of abnormal state operates. As a state when an inverter is normal, if a high potential-based voltage is applied to terminals 30, 31, an electrolytic capacitor is charged to the same voltage. Then, it is applied to a resistor 115 and a Zener diode 112, and LED 113 conducts and emits light, thereby informing of the high potential voltage of the main power supply being applied to the inverter. Upon completion of inverter operation, a charge of the capacitor is discharged while making LED conductive.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inverter circuit device for an electric vehicle, and more particularly to a control circuit for detecting and displaying a driving voltage of a semiconductor element and a main power supply.

[0002]

2. Description of the Related Art A control circuit in a conventional semiconductor device includes:
As disclosed in Japanese Patent Application Laid-Open No. 4-109913, for example, it only discusses circuit means that operates to determine whether switching means to a control terminal is a short-circuit protection operation or a normal operation. It does not describe how to display it.

[0003]

In the above prior art, a method of driving a semiconductor element alone is not described, but a method of driving an entire inverter circuit as a whole system is not described. In a control scheme, the switching elements are at least 4
Since more than two connections (in the case of a two-phase inverter) are generally required, it is unclear which switching element has an abnormality when an abnormality occurs.

SUMMARY OF THE INVENTION An object of the present invention is to provide a display method as an inverter circuit device for an electric vehicle, in which a switching element in which an abnormal drive voltage has been generated can be clearly and visually determined. An object of the present invention is to provide an operation which has a function of displaying that a potential is being supplied and a function of discharging a capacitor charged by a main power supply.

[0005]

According to the present invention, a circuit for driving an IGBT, which is a switching element, is provided with a circuit for detecting an abnormal drive voltage, and further a circuit for holding the detection signal. And detects and displays the held detection signal in another circuit device. In addition, the circuit device includes a circuit for detecting a main power supply and a circuit for discharging a charged charge. .

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG. In FIG. 1, reference numerals 1, 2, 3, 4, 5, and 6 denote IGBTs, which are switching elements.
Switching operations of ON and OFF are performed by 11, 12, 13, 14, and 15, and the electric motor 7 is driven. In addition,
It is also possible to use an element other than the IGBT as the semiconductor element. Terminals 40, 41, 42, 43, 44, 45
Is supplied with a control signal from the main control circuit 21. A high-potential (+) voltage is applied to the terminal 30, a high-potential (-) voltage is applied to the terminal 31, and the electrolytic capacitor 2
0 is connected. Further, the detection signal from the main control circuit 21 is sent from the terminals 52 and 53 to the terminals 54 and 54 of the LED display circuit 22.
55 is input.

FIG. 2 shows an internal circuit of the first drive circuit 10 in FIG.
0, first abnormal signal holding circuit 70, photocoupler 90,
JK flip-flop element 95, inverter gate elements 91, 92, 93, 94, resistors 80, 81, 82,
It is composed of terminals 100, 101, 102, 103.
FIG. 3 shows an embodiment of the present invention, in which an LED is used.
As an internal circuit of the display circuit 22, the photodiode 1
13 (hereinafter referred to as LED), resistors 114, 115, 1
16, Zener diodes 111 and 112, photocoupler 110, and terminals 54 and 55.

An operation example of the LED display circuit of the inverter having the above configuration will be described. In FIG. 1, the main control circuit 2
When a control signal (temporarily control signal 1) is input to terminal 40 from terminal 1 and a control signal (temporary control signal 4) is input to terminal 43, first drive circuit 10 and fourth drive circuit 13 is activated, and a higher potential (+)
A voltage is applied to the electric motor 7 by energizing the IGBT 1, and thereafter, an electric current flows to the terminal 31 to which the (−) voltage of the high potential system is applied by energizing the IGBT 4. When the applied drive voltage deviates from the set value, a circuit for detecting an abnormal drive voltage built in the first gate control circuit 60 operates,
In response to the result, a first abnormal signal holding circuit, which is a circuit for holding a state of being abnormal, operates. Here, it is assumed that corresponding control signals 1 to 6 are input to the first to sixth drive circuits 10 to 15 from terminals 40 to 45 of the main control circuit 21 respectively.

Next, description will be made in detail with reference to FIG. A control signal 1 which is an ON voltage signal of a (+) potential having a predetermined time (temporarily T1) is input from a terminal 40 to a first gate control circuit 60 built in the first drive circuit 10. Then, the IGBT 1 is turned on. If the IGBT 4 is turned on by the fourth drive circuit 13 in this state, the current flows through the IGBT 1 through the electric motor 7. At this time, the voltage between the gate and the emitter electrode of the IGBT 1 is always detected by the first gate control circuit 60. When the voltage deviates from a predetermined value, the terminal 100 has a (+) voltage of a certain potential (for example, the Is output and the resistor 8
When the voltage 1 is applied to 0, the diode of the photocoupler 90 is turned on. Here, it is assumed that a certain (−) voltage is input to the terminal 101.

When the diode of the photocoupler 90 is turned on, the (+) potential of the low voltage system applied to the terminal 102 (tentatively, the voltage 2 is applied, and the (−) potential of the low voltage system is applied to the terminal 103). Current) flows through the transistor of the photocoupler 90, and the input voltage of the inverter gate element 91 changes from the potential of the voltage 2 applied by the resistors 81 and 82. Since the potential is substantially the same as the saturation voltage of the transistor of the photocoupler 90, the inverter gate element 91
Is applied to the input of the inverter gate element 92, and the CK terminal of the JK flip-flop element 95 is connected to the inverter gate element 92.
A voltage of approximately 0 V potential generated at the output section is applied.

As a result, the JK flip-flop element 9
5 is synchronized with the falling edge and the edge of the voltage input to the CK terminal section (however, a reset signal from the main control circuit 21 is input to the CLR terminal from the terminal 104 as appropriate). When a signal of a (+) potential having a certain time (tentatively referred to as time T2) is input from the Q terminal of the JK flip-flop element 95, the voltage of the (+) potential is output to the output of the inverter gate element 94. (Tentatively, voltage 3) is generated, and a signal is transmitted from terminal 46 to terminal 52 of main control circuit 21.

Here, the JK flip-flop element 95
Of the same element even if the potential input to the CK terminal of
Unless a control signal is input from the main control circuit 21 to the LR terminal, the output state of the Q terminal of the same element is maintained. As a result, the voltage of the (+) potential is continuously applied to the input portion of the inverter gate element 93. Therefore, the output portion of the inverter gate element 94 maintains the state of the (+) potential.

Next, description will be made in detail with reference to FIGS. When a signal of (+) potential is input to the terminal 46 of the main control circuit 21, the internal circuit of the main control circuit 21
(+) Having the signal of the error signal 1, that is, the time t1
The mode in which the potential ON voltage is generated once during the time TA is continuously continued, and is transmitted from the terminal 52 to the terminal 54. Here, it is assumed that a low voltage (−) potential which is the same potential as the terminal 53 is applied to the terminal 55.

When a voltage of the (+) potential is applied to the terminal 54, the resistor 114 is energized only during the time t1, and the diode of the photocoupler 110 is turned on. As a result, the current of the LED 113, which has been conducting through the resistor 115 and the Zener diode 112, is cut off, and the Zener diode 111 set to a Zener potential lower than the Zener potential of the Zener diode 112 is cut off.
, A voltage from the resistor 115 is applied, the transistor of the photocoupler 110 is driven to be ON during the time t1, and the LED 113 is turned off during the same period.

Next, when a (-) potential voltage having a time t2 is applied to the terminal 54, the diode of the photocoupler 110 inverts from ON to OFF, and the transistor also inverts from ON to OFF. Again, the resistor 11
The voltage applied to 5 is applied to the Zener diode 112, and the LED 113 is energized, and the light emitting action occurs again.

Therefore, according to the flowchart of the error signal 1 shown in FIG. 4, since the ON voltage is generated once at the time t1 during the time TA, the light is emitted only once continuously at an interval of the time t2. The action will continue.

If the error signal 2 shown in FIG. 4 occurs,
Since the ON voltage at time t1 is generated twice during the time TB, and the OFF voltage at time t3 and time t2 is generated once each, the light emission is performed only twice continuously at intervals of time t2. The operation continues, and the light emission operation of three to six times continues for each of the other error signals 3 to 6 according to the same principle.

Therefore, the error signals 1 to 6 as shown in FIG. 4 correspond to the terminals 46 to 51 of the main control circuit 21 to which the detection signal generated from the abnormal signal holding circuit built in each drive circuit section is inputted. By doing so, it is possible to grasp the location where an abnormal drive voltage is detected based on the number of times of light emission.

Next, as a normal state of the inverter operation, when a high potential system voltage is applied to the terminals 30 and 31, the electrolytic capacitor 20 is charged to the same potential. As a result, the high potential system voltage becomes a resistance. Unit 115 and Zener diode 1
12 when the LED 113 is energized.
The light emitting action occurs due to the characteristics of the LED 113, and it informs that a high potential voltage which is a main power supply is applied to the inverter. Here, it is assumed that a low-potential (-) voltage is applied to the terminal 55 of the LED display circuit 22.

Next, when the inverter operation is completed, the electric charge of the electrolytic capacitor 20 which has been charged to the high-potential-system potential applied to the terminals 30 and 31 until now is:
LE from the resistor 115 through the Zener diode 112
Discharging proceeds while energizing D113.However, when the potential becomes lower than the Zener potential of the Zener diode 112, the discharge is performed through the resistor 116, and the discharge can be surely completed. As a result, the LED 113 Since the light emitting operation is stopped, it is notified that the high potential voltage which is the main power supply is not applied to the inverter.

[0021]

As described above, according to the present invention, in the control circuit for controlling the switching operation of a large current and a high voltage in an inverter device for an electric vehicle, when the switching element portion is abnormal, Although the investigation at the time of was very difficult, as described above, the abnormal time could be visually determined by using the light emitting action of the LED, and the investigation time was drastically reduced. . Further, in the inverter device to which the high-potential voltage is applied, a warning is issued by the light emitting action of the LED and the high-potential voltage is completely discharged, so that electric shock can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram of a control system according to an embodiment of the present invention.

FIG. 2 is a detailed circuit diagram of a first driving circuit 10 in FIG.

FIG. 3 is a detailed circuit diagram of an LED display circuit according to one embodiment of the present invention.

FIG. 4 is a flowchart of an error signal according to an embodiment of the present invention.

[Explanation of symbols]

1-6 IGBT, 7 motor, 10-15 drive circuit, 20 electrolytic capacitor, 21 main control circuit, 22
LED display circuit, 113 ... LED.

Claims (1)

[Claims] In an electric vehicle, an inverter device for driving an electric motor by an AC power supply obtained by switching a semiconductor element from a DC power supply, wherein the semiconductor elements are connected in pairs on a (+) side and a (-) side, A semiconductor drive circuit for switchingly driving the semiconductor element is provided in the inverter device. The semiconductor drive circuit includes a circuit for detecting an abnormal voltage applied to the semiconductor element, and a detection circuit generated by the detection circuit. A circuit that receives a signal, and further has a function of displaying when an abnormal voltage detection signal is generated from the semiconductor drive circuit, a function of displaying a main power supply being turned on, and a function of discharging an electrolytic capacitor charged by the main power supply. An LED display circuit for an inverter, comprising: