KR940004809B1 - Four quadrant travelling/ ressurrection control system and controlling method using insulated gate bipolar transistor - Google Patents

Abstract

The control system for integratedly controlling the running and subsidiary function of heavy vehicles such as electric forklift by using IGBT (Insulated Gate Bipolar Transistor) in a microprocessor, comprises: a sensor (10) for detecting a temporary state of a vehicle; a microprocessor (20) for judging the temporary state of vehicle according to the signal from the sensor and controlling the motion of vehicle; memory (30) for storing parameters in order to drive the vehicle; a gate driving section (40) for transmitting IGBT signal from the microprocessor and protecting IGBT from the over-current; an IGBT section (50) for applying power supply signal to a DC motor according to the signal from the gate driving section; a DC motor connected with the IGBT section.

Description

Quadrant driving / regeneration control system using IGBT and its control method

1 is an overall block diagram of a four-phase driving / regeneration control system using an IGBT according to an embodiment of the present invention.

2 is a detailed circuit diagram of a gate driver according to an exemplary embodiment of the present invention.

3 is a detailed circuit diagram of an IGBT unit according to an embodiment of the present invention.

4 is an operation flowchart of a four-quadrant driving / regeneration control system using an IGBT according to an embodiment of the present invention.

The present invention relates to a four-quadrant driving / regeneration control system using an Insulated Gate Bipolar Transistor (IGBT) and a control method thereof. More specifically, the present invention relates to a vehicle using a microprocessor in a heavy-duty vehicle such as an electric vehicle. Integrated control of additional functions, the configuration of the regenerative four-quadrant chopper using the IGBT, so that the direction can be easily changed in a contactless manner, and the IGBT which minimizes the power consumption of the battery by the energy regeneration. It relates to a quadrant traveling / regenerative control system used and a control method thereof.

Today, heavy equipment in construction and industry plays an important role in industrial development. If there is a forklift as a means for unloading and transporting various types of heavy equipment among these heavy equipment, these forklifts are roughly classified into engine forklifts and electric forklifts depending on whether they use an engine or a motor.

Since engine forklifts are accompanied by noise and pollution, electric forklifts are becoming more and more preferred as noise-free equipment. Recently, the expansion of microprocessors and the improvement of application technology are applied not only to all industrial control areas but also to driving control areas of electric forklifts. This has resulted in the availability of equipment for the integrated control and supervision of driving speeds and other performance capabilities.

In addition, SCR has been mainly used as a switching device in the past, but since the early 1980s, bipolar transistors have been widely commercialized as power control devices, and recently, IGBTs have been applied as power control devices with better performance than these transistors.

However, the control method of the conventional electric forklift truck, which is mass-produced in domestic and foreign countries until now, is mostly a two-limit control method. In order to change direction, a mechanical contact such as a magnetic contactor having a large current capacity is usually added. Therefore, it is difficult to operate smoothly at the time of starting or stopping, and there is a problem of low sacrifice efficiency at the time of energy sacrifice.

In addition, the conventional electric forklift has not yet applied an IGBT as a driving control element. Thus, when the IGBT is used as the driving method of the electric forklift, the driving circuit is simplified, but the driving gate protection circuit is required due to the sensitive gate characteristics. There is a difficulty that requires know-how.

In addition, the conventional electric forklift has a disadvantage in that the driver needs to redesign the hardware part of the control system or control the variable volume when the driver wants to change the vehicle characteristic to suit his or her driving preference. When using such a variable volume, there is a problem in that the setting state is changed by a mechanical shock and the fine setting is difficult. In particular, the conventional electric forklift cannot allow the driver to set the characteristics other than the start state, that is, the plugging state, the distance, the stopping speed, the current value control, etc. to suit the driver's taste.

In terms of protection of the vehicle, the conventional electric forklift truck does not have an overcurrent control function when the overcurrent is set, so that the motor is not overwhelmed when the vehicle is overloaded for a certain period of time. It is easy to be damaged.

In addition, the existing electric forklift truck is not equipped with a device that can remember the number of times of work or the position of the fork, so the amount of work may not be known, and it is unskilled when performing continuous repetitive work of a certain height. In this case, the work efficiency is bad.

An object of the present invention is to eliminate the above-mentioned problems, and to control the driving and other additional functions of the electric forklift by using a 16-bit Intel MCS96 series MPU, and regenerative four-quadrant using IGBT. It is to provide a four-quadrant driving / regeneration control system using IGBT and its control method that can be easily changed in a contactless manner by configuring a chopper and minimize the power consumption of the battery by energy regeneration. .

Compared to SCR and bipolar transistors, the IGBT has a very simple gate driving circuit, which enables miniaturization, and has a high switching speed, thus making it easy to configure an input filter and providing high power conversion efficiency for low voltage high current control such as an electric forklift. It is very suitable.

The pulse width modulation (PWN) method was used as the driving method of the IGBT gate, and the PWN pulse was generated by software to directly drive the IGBT gate to reduce the influence of external noise and to minimize the driving unit. In addition, the driving and working characteristics of the electric forklift allow the driver to change the parameters stored in the nonvolatile memory of the control device from the outside, thereby achieving superior performance in terms of economy and workability compared to the conventional electric forklift.

The configuration of the present invention for achieving the above object, the sensor unit for detecting the current state of the vehicle; A microprocessor connected to the sensor unit and determining a current state of the vehicle according to a signal input from the sensor unit and controlling the operation of the vehicle; A memory connected to the microprocessor and storing various parameters for driving the vehicle by the microprocessor; A gate driver connected to the microprocessor and transmitting the IGBT drive signal output from the microprocessor and protecting the IGBT from overcurrent; An IGBT unit connected to the gate driver and the power signal line to apply a power signal to a DC motor according to an output signal of the gate driver; It consists of a DC motor connected to the IGBT section.

Another configuration of the present invention for achieving the above object is to display the initial screen after setting the initial value; It is determined whether the user selects one mode among the various modes provided in the main mode, and when the user selects the mode, the user branches to the mode selection step 130 after setting the self-diagnosis and various parameters according to the selected mode. ; If the user does not select a mode, it is determined whether the electric forklift is in operation, and the self-diagnosis is executed when the electric forklift is in operation; Judging whether an abnormality occurs after the self-diagnosis, and if the abnormality does not occur, judging whether the load is greater than the maximum value; In case of an error or when the load is greater than the maximum value, a warning is displayed.

With reference to the accompanying drawings, a preferred embodiment of the present invention by the above configuration will be described in detail.

1 is an overall block diagram of a four-quadrant driving / regeneration control system using an IGBT according to an embodiment of the present invention. As shown in FIG. 1, the configuration of the four-quadrant driving / regeneration control system using the IGBT according to the embodiment of the present invention includes a microprocessor in which a sensor unit 10 and an input terminal are connected to an output terminal of the sensor unit 10. 20, a memory 30 connected to the microprocessor 20, a gate driver 40 having an input terminal connected to an output terminal of the microprocessor 20, an output terminal and a power supply of the gate driver 40. An IGBT unit 50 having an input terminal connected to the signal lines B + and B- and a DC motor M having an input terminal connected to an output terminal of the IGBT unit 50.

The sensor unit 10 includes a plurality of temperature sensors for sensing the temperature of the motor and the IGBT, a plurality of Hall sensors for detecting the armature current and the regenerative current, a hydraulic sensor for detecting the load of the load, and a battery. It consists of a sensor for detecting the liquid level, and a speed sensor for detecting the speed of the electric forklift.

In the embodiment of the present invention, an 8096 chip or an 8097 chip of Intel Corporation is used as the microprocessor 20, but the technical scope of the present invention is not limited thereto.

2 is a detailed circuit diagram of a gate driver according to an exemplary embodiment of the present invention. As shown in FIG. 2, the gate driver according to the exemplary embodiment of the present invention has an input terminal IN connected to output signal lines S1 to S4 of the microprocessor 20, and a power supply voltage signal line Vss. The capacitor C40 connected between the first and third high voltage gate drivers 41 and 43 and the second and fourth gate drivers 42 and 44 connected to the voltage terminal Vss, respectively, and the power voltage signal lines Vcc and Vss. C43) The second and fourth gates, the capacitors C44 and C45 connected between the error terminal ERR and the voltage terminal VSS of the drivers 42 and 44, and the first and third high voltage gate drivers 41, 43) and resistors R40 to R49 having one terminal connected to the output terminals of the second and fourth gate drivers 42 and 44, respectively, and a diode having a cathode connected to the other terminal of the resistors R40 to R43 respectively. An anode is connected to the other terminals of the resistors D44 to 43 and R44 to 47, respectively, and a cathode is connected to the anodes of the diodes D40 to D43, respectively. Anodes are connected to the diodes D44 to D47 and the other terminals of the resistors R48 to R49, respectively, and a cathode is connected to the voltage terminals Vs of the first and third high voltage gate drivers 41 and 43, respectively. Resistors R4A and R4B connected between the current sensing terminals CS of the second and fourth gate drivers 42 and 44 and the anodes of the diodes D48 and D49, respectively; The capacitors C46 and C48 and the second and fourth gate drivers 42 and 44 connected between the voltage terminals V _B and the current sensing terminals CS of the first and third high voltage gate drivers 41 and 43, respectively. And capacitors C47 and C49 respectively connected between the voltage terminals Vcc and VS.

In the embodiment of the present invention, an IR2125 chip manufactured by International Rectifier Co., Ltd. is used as the first and third high voltage gate drivers 41 and 43, and the second and fourth gate drivers 42 and 44 are manufactured by the same company. Although the IR2121 chip is used, the technical scope of the present invention is not limited thereto.

3 is a detailed circuit diagram of an IGBT unit according to an embodiment of the present invention. As shown in FIG. 3, in the configuration of the IGBT unit according to the embodiment of the present invention, the drain terminal is connected to the power supply voltage signal line B +, and the gate terminal is connected to the output signal lines G1 and G3 of the gate driver 40, respectively. The drain terminal is connected to the first and third IGBTs Q51 and Q53 and the source terminals of the first and third IGBTs Q51 and Q53, respectively, and the source terminal is connected to the power voltage signal line B-, respectively. Gate terminals are respectively connected to the output signal lines G2 and G4 of 40, and anodes are respectively connected to the source terminals of the second and fourth IGBTs Q52 and Q54 and the first to fourth IGBTs Q51 to Q54. Diodes D51 to D54 having cathodes connected to the drain terminals of the first to fourth IGBTs Q51 to Q54, respectively, and resistors having one terminal connected to the drain terminals of the first to fourth IGBTs Q51 to Q54, respectively. Connected between the other terminal of the resistors R51 to R54 and the resistors R51 to R54 and the sohose terminals of the first to fourth IGBTs Q51 to 54, respectively. Capacitors C51 to C54.

4 is an operation flowchart of a four-quadrant driving / regeneration control system using an IGBT according to an embodiment of the present invention. As shown in FIG. 4, the operation of the four-quadrant driving / regeneration control system using the IGBT according to the embodiment of the present invention includes a start step 110 for setting an initial value, a step 120 for displaying an initial screen, Step 130 of determining whether a user has selected one of the various modes provided in the main mode, and the mode selection step after setting the self-diagnosis and various parameters according to the selected mode when the user selects the mode Step 140 branching to 130, determining whether the electric forklift is working when the user does not select the mode 150, and performing self-diagnosis when the electric forklift is working (160) ), Determining whether an abnormality has occurred after self-diagnosis (170); determining whether the load load is greater than the maximum value when no abnormality is issued, and when an abnormality occurs or the load It is a step 190 to display a warning in the case larger than the maximum value.

The operation of the four-quadrant driving / regeneration control system using the IGBT according to the embodiment of the present invention according to the above-described configuration and operation flow and its control method are as follows.

When the user applies power to operate the electric forklift, the quadrant driving / regeneration control system using the IGBT operates.

When the operation of the four-quadrant driving / regeneration control system using the IGBT is started, the microprocessor 20 sets the initial value while displaying a logo such as a company name on the screen through a display device (not shown).

Next, the microprocessor 20 determines whether there is a user's mode selection input through an input device (not shown) while displaying the main mode on the screen of the display device. When there is a user's mode selection input, the microprocessor 20 resets various parameters necessary for the self-diagnosis and the operation of the electric forklift truck to the memory 30 according to the selected mode, and then returns to the main mode, thereby allowing the user to self-diagnose. And various parameters can be set continuously.

When there is no mode selection input by the user through the input device, the microprocessor 20 determines whether the electric forklift is in operation by reading a signal input through the sensor unit 10.

When the electric forklift is in operation, the microprocessor 20 determines whether an abnormality has occurred in the electric forklift by diagnosing the state of the electric forklift through the sensor unit 10. If an error occurs in the electric forklift, the microprocessor generates a warning sound through a warning device (not shown) or lights a warning light to alert the user.

When no abnormality occurs in the electric forklift, the microprocessor 20 reads the load of the load through the sensor unit 10 and compares it with the maximum value stored in the memory 30 to determine whether the load of the load deviates from the maximum. If the load of the load exceeds the maximum value, a warning sound is generated through the warning device or the warning light is turned on to warn the user. When the load of the load does not exceed the maximum value, the microprocessor 20 returns to the main mode.

In addition, when the electric forklift is in operation, the microprocessor 20 receives a DC motor through the gate driver 40 and the IGBT unit 50 according to a signal input by a user through an operating device (not shown). By controlling M), the electric forklift can be driven.

When the user intends to drive the electric forklift in the forward direction, the microprocessor 20 outputs the output signals S1 and S2 in the high state and the output signals S3 and S4 in the Luo state to the gate driver 40.

When the output signals S1 and S2 of the high state are applied from the microprocessor 20 to the input terminals IN of the first high voltage gate driver 41 and the second gate driver 42 of the gate driver 40, the first signal is applied. After the output signal OUT of the high state is generated by the high voltage gate driver 41 and the second gate driver 42, the diodes D44 and D45 are output to the IGBT unit 50 as the output signals G1 and G2. Is approved.

When the output signals G1 and G2 in the high state are applied from the gate driver 40, the first and second IGBTs Q51 and Q52 of the IGBT unit 50 are turned on, so that the power voltage signal B + and the first IGBT Q51 are turned on. As the current flows through the DC motor M, the second IGBT Q52, and the power voltage signal B-, the DC motor M is driven in the forward direction as the current flows through the DC motor M. do. At this time, the third and fourth IGBTs Q53 and Q54 are turned off.

However, when the user wants to drive the electric forklift in the reverse direction, the microprocessor 20 M outputs the high output signals S3 and S4 and the low output signals S1 and S2 to the gate driver 40. .

When the output signals S3 and S4 of the high state are applied from the microprocessor 20 to the input terminal IN of the third high voltage gate driver 43 and the fourth gate driver 44 of the gate driver 40, After the output signal OUT of the high state is generated by the high voltage gate driver 43 and the 44th gate driver 44, the diodes D46 and D47 are used to output the output signals G3 and G4 to the IGBT unit 50. Is approved.

When the output signals G3 and G4 in the high state are applied from the gate and driver 40, the third and fourth IGBTs Q53 and Q54 of the IGBT unit 50 are turned on, so that the power voltage signal B + and the third IGBT ( As the current flows through the Q53), the DC motor M, the fourth IGBT Q54, and the power voltage signal B-, the DC motor M is driven in the reverse direction as the current flows through the DC motor M. do. At this time, the first and second IGBTs Q51 and Q52 are in a turn-off state.

Therefore, the electric forklift truck can move forward and backward in accordance with the drive of the DC motor M. In the case of operating in this way, it is possible to prevent waste of power by converting energy to the power supply side through the regenerative mode.

The operation state of the four-quadrant IGBT according to the embodiment of the present invention can be classified into four modes of forward power control mode, forward regeneration mode, reverse power control mode, and reverse regeneration mode.

The forward power control mode is a forward operation mode when the first and second IGBTs Q51 and Q52 are turned on and the third and fourth IGBTs Q53 and Q54 are turned off. The first and second IGBTs are in the condition that the forward switch is turned on. Pulses are applied to the gates of Q51 and Q52, and the width of the pulses applied at this time is controlled by the microprocessor 20 according to the state of the accelerator so that the traveling speed in the forward direction can be varied.

The reverse power control mode is an operation mode when the third and fourth IGBTs Q53 and Q54 are turned on and the first and second IGBTs Q51 and Q52 are turned off, in contrast to the forward power control mode. The microprocessor 20 controls the width of the pulses applied to the gates of the third and fourth IGBTs Q53 and Q54 according to the state of the accelerator so that the traveling speed in the reverse direction can be varied.

The forward regeneration mode is an operation mode when the forward switch is changed from the on state to the off state, and the first IGBT Q51 is first turned off among the first and second IGBTs Q51 and Q52 that are turned on, and then the second IGBT Q52 is turned on. ) Will be turned off later. When the first IGBT Q511 is first turned off, the current flowing to the DC motor M flows through the second IGBT Q52 and the diode D54. Next, when the second IGBT Q52 is turned off, the counter electromotive force is instantaneously generated in the DC motor M. At this time, the current flowing through the DC motor M is recharged to the power supply voltage B + side through the diode D51.

The reverse regenerative mode is an operation mode when the reversing switch is changed from the on state to the off state, and the third IGBT (Q54) is first turned off among the third and fourth IGBTs Q51 and Q52 which are turned on. Q53) is a mode that is later turned off. When the fourth IGBT Q54 is first turned off, the current flowing to the DC motor M flows through the third IGBT Q53 and the diode D51. Next, when the third IGBT Q53 is turned off, the counter electromotive force is instantaneously generated in the DC motor M. At this time, the current flowing through the DC motor M is recharged to the power supply voltage B + side through the diode D53.

As described above, in the embodiment of the present invention, the microprocessor is used to integrally control the driving and other additional functions of the electric forklift, and it is easy to change the direction in a contactless manner by configuring a regenerative four-quadrant chopper using the IGBT. In addition, it is possible to provide a four-quadrant driving / regeneration control system using IGBT and its control method having the effect of minimizing the power consumption of the battery by regeneration of energy. This effect of the invention can be used in the field of heavy duty vehicles requiring IGBTs, including electric forklifts.

Claims (4)

A sensor unit for detecting a current state of the vehicle; A microprocessor connected to the sensor unit and determining a current state of the vehicle according to a signal input from the sensor and controlling the operation of the vehicle; A memory connected with the microprocessor and storing various parameters necessary for driving the vehicle by the microprocessor; A gate driver connected to the microprocessor and transmitting the IGBT driving signal output from the microprocessor and protecting the IGBT from overcurrent; An IGBT unit connected to the gate driver and the power signal line to apply a power signal to the DC motor in accordance with the output signal of the gate driver; A quadrant driving / regeneration control system using an IGBT, characterized in that it comprises a DC motor connected to the IGBT unit. The gate driver of claim 1, wherein the gate driver includes an input terminal IN connected to the output signal lines S1 to S4 of the microprocessor 20 and a voltage terminal Vss connected to the power supply voltage signal line Vss. 41 to 444); Capacitors C40 to C43 connected between the power supply voltage signal lines Vcc and Vss; Capacitors C44 and C45 connected between the error terminal ERR and the voltage terminal Vss of the gate drivers 42 and 44; Resistors R40 to R49 having one terminal connected to the output terminals of the gate drivers 41 to 44; Diodes D40 to D43 having a cathode connected to the other terminal of the resistors R40 to R43; Diodes D44 to D47 having an anode connected to the other terminal of the resistors R44 to R47 and a cathode connected to the anodes of the diodes D48 to D43; Diodes D43 and D49 having an anode connected to the other terminals of the resistors R48 and R49 and a cathode connected to the voltage terminals Vs of the gate drivers 41 and 43, respectively; Resistors R4A and R4B connected between the current sensing terminals CS of the gate drivers 42 and 44 and the anodes of the diodes D48 and D49; Capacitors C46 and C48 connected between the voltage terminals V _B and the current sensing terminals CS of the gate drivers 41 and 43; A quadrant driving / regeneration control system using an IGBT, comprising capacitors C47 and C49 connected between voltage terminals Vcc and VS of the gate drivers 42 and 44. 2. The IGBT unit according to claim 1, wherein the IGBT unit comprises: an IGBT (Q51, Q53) having a drain terminal connected to a power voltage signal line (B +) and a gate terminal connected to an output signal line (G1, G3) of the gate driver 40; An IGBT Q52 having a drain terminal connected to the source terminals of the IGBTs Q51 and Q53, a source terminal connected to the power supply voltage signal line B-, and a gate terminal connected to the output signal lines G2 and G4 of the gate driver 40. , Q54) and; Diodes D51 to D54 having an anode connected to the source terminals of the IGBTs Q51 to Q54 and a cathode connected to the drain terminals of the IGBTs Q51 to Q54; Resistors R51 to R54 having one terminal connected to the drain terminals of the IGBTs Q51 to Q54; A quadrant driving / regeneration control system using an IGBT, comprising capacitors (C51 to C54) connected between the other terminal of the resistors (R51 to R54) and the source terminals of the IGBTs (Q51 to Q54). After setting the initial value, display the initial screen; From the various modes provided in the main mode, it is determined whether the user has selected one mode, and when the user selects the mode, the user branches to the mode selection step 130 after setting the self-diagnosis and various parameters according to the selected mode. ; If the user does not select a mode, it determines whether the electric forklift is in operation, and performs self-diagnosis when the electric forklift is in operation; Judging whether an abnormality has occurred after self-diagnosis, and if the abnormality has not occurred, it is determined whether the load is greater than the maximum value; A control method for a four-quadrant driving / regeneration system using an IGBT, characterized by displaying a warning when an abnormality occurs or when the load is greater than the maximum value.