KR102011513B1 - Safety operation method of power converter for hybrid construction equipment - Google Patents

Abstract

The present invention relates to a power semiconductor device of a hybrid construction machine (DC / AC inverter for an engine auxiliary motor, DC / AC inverter for a swing motor, and DC / DC converter for an ultra capacitor) in a power semiconductor device such as an IGBT at the start of operation of a system. By suggesting the detection method of device short / open, it is possible to improve the safety of the system and the driver by preventing the connection to a failure or spreading to a larger accident when a system error occurs.

Description

SAFETY OPERATION METHOD OF POWER CONVERTER FOR HYBRID CONSTRUCTION EQUIPMENT}

The present invention relates to a method for safely driving a power conversion device for a hybrid construction machine, and more particularly, a method for determining an abnormality of a power conversion device such as an inverter or a converter composed of upper or lower semiconductor elements included in a hybrid construction machine and a hybrid. It relates to a safe driving method of a power conversion device for construction machinery.

In recent years, with the rapid increase in oil prices, research on hybrid construction machinery that improves fuel efficiency by storing surplus power of the engine in the battery and supplying the insufficient power of the engine from the battery has been actively conducted.

As such, a system using an engine and an electric motor as a common power source and having an electrical energy storage device is called a hybrid system. For example, hybrid systems include hybrid systems for heavy equipment such as hybrid cars and excavators.

Meanwhile, a general excavator system uses an engine as a power source to perform an operation of turning or driving a boom, an arm, and a bucket, which are final loads, through a medium called hydraulic pressure. In contrast, the hybrid excavator system can improve the overall efficiency of the excavator system by installing two motors and an electric storage device in the general excavator. Major components added to the hybrid excavator system include motors, electrical storage devices, inverters and converters. Here, the electrical storage device includes a battery and an ultra-capacitor (UC).

1 shows the configuration of a conventional hybrid excavator electrical system.

As shown in FIG. 1, the power supply device 100 of the hybrid excavator system includes a switching mode power supply 110, a logic control board 120, an engine auxiliary motor inverter 130, a turning motor inverter 140, and a DC. Link capacitor 150 and ultra-capacitor converter 160 that is a DC-DC converter. Here, the switching mode power supply unit 110, the logic control board 120, the engine auxiliary motor inverter 130, the swing motor inverter 140 and the ultra capacitor converter 160, respectively, the control board battery 101, excavator electric It is connected to the device 102, the engine auxiliary motor 103, the turning motor 104 and the ultra capacitor 105.

The switched-mode power supply (SMPS) 110 is connected to the control board battery 101 to supply power to the logic control board 120.

The logic control board 120 senses the voltage of the ultra capacitor 105 and the voltage of the DC link capacitor 150 and controls the initial driving logic.

The engine auxiliary motor inverter 130 is a DC / AC inverter, and functions to charge the DC link capacitor 150 by the engine auxiliary motor 103 driven by an AC voltage. Here, the engine auxiliary motor 103 is driven by an AC voltage, is directly connected to the engine, and rotates at the same rotation speed (rpm) as the engine when the engine is driven.

The swing motor inverter 140 is a DC / AC inverter, and when the power contactor of the ultra capacitor 105 which is a DC voltage is turned on, the swing motor 104 is driven by an AC voltage according to a charged voltage. To drive the function. Here, the swing motor 104 generates power required for the swing operation of the excavator.

The DC link capacitor 150 charges the DC voltage converted by the engine auxiliary motor inverter 130. The DC link capacitor 150 is connected to the ultra capacitor converter 160.

The ultra capacitor converter 160 performs a function of charging the ultra capacitor 105 through the UC link capacitor 170 using the electrical energy stored in the DC link capacitor 150. The ultra capacitor converter 160 is connected between the DC link capacitor 150 and the UC link capacitor 170, and the UC link capacitor 170 is connected to the ultra capacitor 105. Here, the ultra capacitor converter 160 is a DC / DC converter, and the ultra capacitor 105 is charged with the voltage converted by the ultra capacitor converter 160.

As described above, power conversion devices such as the engine auxiliary motor inverter 130 that is a DC / AC inverter, the turning motor inverter 140, and the ultra capacitor converter 160 that is a DC / DC converter include an insulated gate bipolar transistor, A number of power driving semiconductor devices such as IGBTs are included. IGBT is a junction type transistor in which a metal oxide semiconductor field effect transistor (MOSFET) is incorporated into a gate part, and is a self-extinguishing type in which a voltage between the gate and emitter is driven to turn on and off by an input signal. This is a possible semiconductor device.

On the other hand, in IGBT driving-only ICs, the arm short, that is, the upper IGBT element and the lower IGBT element are shorted at the same time, so that the (+) terminal and the (-) terminal are directly connected, which may cause damage to the device. Therefore, typical IGBT drive-only ICs have arm-short detection or arm-short protection. Common malfunctions of power converters include overheat detection protection, overcurrent detection protection, and overvoltage detection protection. These protection functions are 100% protection against damage such as short / open of power semiconductor switch such as IGBT. It is impossible. In other words, the current Arm-Short detection / protection function is limited protection operation, and there is a case that protection is not possible. In particular, failure such as short / open of a power semiconductor switch such as IGBT is detected in advance. Need to be determined.

The present invention is derived to solve the above-mentioned problems, the present invention is a power conversion device of the hybrid construction machine (DC / AC inverter for engine auxiliary motor, DC / AC inverter for swing motor and DC / DC converter for ultra capacitor) In this paper, we propose an error determination method for short / open of a power semiconductor device such as IGBT at the start of system operation so that it is not connected to a failure or spread to a larger accident when a system error occurs. It is an object of the present invention to provide a safe driving method of a power conversion device for a hybrid construction machine that can improve the safety.

In order to achieve the above object, the present invention proposes a safe driving method of a power conversion device for a hybrid construction machine. According to a safe driving method of a power conversion device for a hybrid construction machine according to the present invention, a system such as Short / Open is broken in a state in which a gate signal of a large power semiconductor device IGBT is not applied before system start. After checking in advance and confirming the normal state, by connecting the electric energy storage device (UC, Ultra Capacitor) and applying the gate signal, it prevents the failure from spreading by accident and improves the driver's safety.

More specifically, the present invention relates to an engine auxiliary motor for starting an engine, a load motor, an electric system, and a hybrid construction machine to include a DC link capacitor for storing electric energy generated from the engine auxiliary motor, and the DC link. The present invention is applied to a hybrid construction machine including a UC link capacitor for storing electric energy stored in a capacitor, electric energy generated from the engine auxiliary motor, and electric energy generated by power generation driving of the load motor.

In such a hybrid construction machine, the present invention provides a safe driving method of a power conversion device for a hybrid construction machine comprising a plurality of upper semiconductor switches (Q1, Q2, Q3) and a plurality of lower semiconductor switches (Q4, Q5, Q6). Suggest.

The safe driving method of the power converter according to the present invention includes a plurality of upper semiconductor switches (Q1, Q2, Q3) in a hybrid construction machine including an engine auxiliary motor, a load motor, and an electric system for starting an engine. In the safe driving method of a power conversion device for a hybrid construction machine having a plurality of lower semiconductor switches (Q4, Q5, Q6), any one of the upper semiconductor switches (Q1, Q2, Q3) and the A signal applying step of applying a signal sequentially or simultaneously to any one of the lower semiconductor switches Q4, Q5, and Q6; A current checking step of checking whether current flows from one end of the power converter to the other end or from the other end of the power converter; And when the current flows from one end of the power converter to the other end or the other end, activates the electric system when it is normal, and when the current does not flow from one end of the power converter to the other end or the other end of the power converter. And an abnormality determination step of judging at least one of the upper semiconductor switches Q1, Q2, and Q3 and the lower semiconductor switches Q4, Q5, and Q6.

In the safe driving method, when it is determined that at least one or more of the upper semiconductor switches Q1, Q2 and Q3 and the lower semiconductor switches Q4, Q5 and Q6 are linked, the power converter and the ultracapacitor UC link. The method may further include a safe driving step of not connecting the capacitor or applying a gate driving pulse signal to the upper semiconductor switches Q1, Q2 and Q3 and the lower semiconductor switches Q4, Q5 and Q6.

On the other hand, there are two types of power converters, namely DC / AC inverters such as inverters for engine auxiliary motors and inverters for swing motors, and DC / DC converters such as converters for ultracapacitors. According to the two types, the specific safe driving method is differently adopted.

In the case of a converter of a power conversion device, the signal applying step may include the upper semiconductor switch Q1 when one end of the power conversion device is connected to a DC link capacitor and the other end of the power conversion device is a converter connected to a UC link capacitor. , An upper side applying step of sequentially applying a signal to each of Q2 and Q3); And a lower applying step of sequentially applying signals to the lower semiconductor switches Q4, Q5, and Q6 after the upper applying step, respectively.

In the abnormality determining step, when no current flows from one end to the other end or the other end of the power converter, the upper semiconductor switch is checked by checking whether the UC link capacitor is charged or discharged and whether the DC link capacitor voltage is changed. It is characterized in that it is determined to be at least one of Open or Short of (Q1, Q2, Q3) or the lower semiconductor switches Q4, Q5, Q6.

In the case of a converter of a power conversion device, the signal applying step may include: when one end of the power conversion device is connected to a UC link capacitor, and the other end of the power conversion device is an inverter connected to the engine auxiliary motor or the load motor. After selecting one of the upper semiconductor switch (Q1, Q2, Q3) and the lower semiconductor switch (Q4, Q5, Q6), respectively, characterized in that the signal is applied to the selected upper semiconductor switch and the selected lower semiconductor switch at the same time.

The abnormality determining step may include determining whether the DC link capacitor voltage is changed when the current does not flow in the engine auxiliary motor or the load motor, thereby selecting the selected upper semiconductor switch, the selected lower semiconductor switch, or the selected upper semiconductor switch. The method may determine whether the upper semiconductor switch and the lower semiconductor switch connected to the selected lower semiconductor switch are open or short.

According to a safe driving method of a power conversion device for a hybrid construction machine according to the present invention, the system operation can be started after determining the normal state of the electric system and confirming that it is normal before the electric system is activated (gate signal applied) at the start of the vehicle. Therefore, it is possible to prevent the spread to secondary larger failures that may occur when the system operation is performed while overlooking whether the electric system is open or shorted, and the driver's safety can be secured.

That is, according to the safe driving method of the power conversion device for a hybrid construction machine according to the present invention, in the state that the gate signal of the high-power semiconductor device IGBT is not applied before the system start (Key On), failure of a system such as Short / Open After checking the presence and confirming the normal state, connecting the electric energy storage device (UC, Ultra Capacitor) and applying the gate signal prevents the failure from spreading by accident to improve the driver's safety.

1 is a block diagram of a conventional hybrid excavator electrical system.
2 is a detailed view when the power conversion device is a DC / DC converter, i.e., converter 160 for ultracapacitors.
3A to 3F are diagrams for explaining a process of checking whether a semiconductor device is open or short when the output converter is a DC / DC converter;
4 illustrates a UC link capacitor 170 charge and discharge profile.
5 is a flowchart illustrating a process of checking whether a semiconductor device is open or short when the power converter is a DC / DC converter.
6 is a detailed view when the power conversion device is a DC / AC inverter, that is, the engine auxiliary motor inverter 130 or the swing motor inverter 140.
7A to 7C, a diagram for describing a process of checking whether a semiconductor device is open or short when the power converter is a DC / AC inverter;
8 is a flowchart illustrating a process of checking whether a semiconductor device is open or short when the power converter is a DC / AC inverter;
9 is a diagram showing a three-phase AC motor current waveform according to pulse application of upper and lower semiconductor elements Q1, Q2, Q3 / Q4, Q5, and Q6.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. The construction of the present invention and the effects thereof will be clearly understood through the following detailed description. Prior to the detailed description of the present invention, the same components are denoted by the same reference numerals as much as possible even if displayed on different drawings, and a detailed description thereof will be omitted when it is determined that the subject matter of the present invention may obscure the gist of the present invention.

Hereinafter, the present invention is a case of a DC / DC converter included in a power converter, that is, a converter for an ultracapacitor (Example 1), and a case of a DC / AC inverter, that is, an inverter for an engine auxiliary motor or an inverter for a turning motor (an embodiment). The description will be divided into Example 2).

The DC / DC converter, that is, the converter for the ultracapacitor (Example 1) will be described.

FIG. 2 shows a detailed view of the DC / DC converter included in the power converter, that is, the converter 160 for the ultracapacitor.

As shown, the converter 160 for the ultracapacitor is located between the DC link capacitor 150 and the UC link capacitor 170, and the plurality of upper power semiconductor devices (Q1, Q2, Q3) such as a plurality of IGBTs Comprising the lower power semiconductor elements (Q4, Q5, Q6), the current transformer (CT) for detecting the inductor and current between the upper and lower semiconductor elements (Q1, Q2, Q3 / Q4, Q5, Q6) and the UC link capacitor 170. , Current Transformer).

When the power converter is a DC / DC converter, that is, the converter 160 for the ultracapacitor, the open / short check of the semiconductor device is performed as shown in Tables 1 and 2 below.

Upper element Open Check Bottom element Short Check
[Performed in UC Link Capacitor 170 Discharge State] (1) Applying short (approximately several ON) pulses to the upper elements Q1, Q2, and Q3 in sequence - (2) Normal current flows and the UC link capacitor 170 voltage is charged Upper element normal (3) No current flows and no DC link capacitor 150 voltage fluctuations Upper element open (4) Current flow uncheckable, DC link capacitor 150 voltage quickly discharged Lower element Short

Lower device open check / upper device short check
[Performed in UC Link Capacitor 170 Charge] (1) Applying short (approximately several ON) pulses to the lower elements Q4, Q5, and Q6 in sequence - (2) Normal current flows and the UC link capacitor 170 voltage discharges Lower element normal (3) No current flows and no DC link capacitor 150 voltage fluctuations Lower element open (4) Current flow uncheckable, DC link capacitor 150 voltage quickly discharged Upper element Short

3A to 3C, a process of checking whether a semiconductor device is open or short in the case of a DC / DC converter included in a power converter, that is, an ultracapacitor converter 160 will be described.

3A to 3C illustrate examples of the upper element open check / lower element short check of Table 1. As shown in Table 1, the upper element open check / lower element short check is applied to the upper element (Q1, Q2, Q3) in sequence with short (approximately several ON) pulses while the UC link capacitor 170 is discharged. By applying.

FIG. 3A illustrates the normal mode. When the ON pulse is applied to the upper element Q1, the energy of the DC link capacitor 150 is turned on through the upper element Q1, the current transformer CT, and the inductor. The current flows through the capacitor 170, and the energy of the DC link capacitor 150 is charged to the UC link capacitor 170.

However, when the lower element Q4 has a short fault, the upper element Q1 is turned on by applying an ON pulse to the upper element Q1 as shown in FIG. (Arm Short) occurs and a large current flows from the upper element Q1 through the lower element Q4 to cause a voltage variation of the DC link capacitor 150, and a current change is not detected in the current transformer CT. 170) also does not charge.

When the upper element Q1 is an open fault, as shown in FIG. 3C, there is no current flowing through the upper element Q1 and the UC link capacitor 170 is not charged.

3D to 3F illustrate examples of the lower device open check / upper device short check in Table 2. As described in Table 2, the upper element open check / lower element short check generates a short (about several milliseconds) ON pulses to the lower elements (Q1, Q2, Q3) in sequence with the UC link capacitor 170 charged. By applying.

3D illustrates the normal mode, when the ON pulse is applied to the lower element Q4, the energy of the UC link capacitor 170 is discharged through the lower element Q4 which is in the ON state.

However, when the upper element Q1 has a short fault, as shown in FIG. 3E, the lower element Q4 is turned on by applying an ON pulse to the lower element Q4, and at the same time, the upper element Q1 and the arm short fault are short. (Arm Short) occurs and a large current flows from the upper element Q1 through the lower element Q4 to cause a voltage variation of the DC link capacitor 150, and a current change is not detected in the current transformer CT. 170 also does not discharge.

When the lower element Q4 has an Open fault, as shown in FIG. 3F, there is no current flowing through the lower element Q4, and the UC link capacitor 170 is not discharged.

4 illustrates the UC link capacitor 170 charge and discharge profile.

As shown, when the driving pulses T0 to T1 are applied to the upper IGBTs Q1, Q2 and Q3 of the ultracapacitor converter 160, the UC link capacitor 170 is charged and the lower IGBTs Q4. When the driving pulses T2 to T4 are applied to the Q4 and Q6, the UC link capacitor 170 is discharged.

On the other hand, when the upper IGBT (Q1, Q2, Q3) or the lower IGBT (Q4, Q4, Q6) is broken, the driving pulses T4 to T5 in the upper IGBT (Q1, Q2, Q3) of the converter 160 for the ultracapacitor. ), The UC link capacitor 170 is not charged, and when the driving pulses T6 to T7 are applied to the lower IGBTs Q4, Q4, and Q6, the UC link capacitor 170 is not discharged. You can check it.

5 is a flowchart illustrating a process of checking whether a semiconductor device is open or short in the case of a DC / DC converter included in a power converter, that is, an ultracapacitor converter 160.

When the test is started (S1), a short (approximately several ON) ON pulses are sequentially applied to the upper elements Q1, Q2, and Q3 for the upper element open check / lower element short check (S2).

Then, the inductor current is confirmed and whether the UC link capacitor 170 is charged (S3). If the inductor current is confirmed and the charging of the UC link capacitor 170 is confirmed (FIG. 3A), the upper elements Q1, Q2, and Q3 are normal.

Next, a short (approximately several ON) ON pulses are sequentially applied to the lower elements Q4, Q5, and Q6 for the lower element open check / upper element short check (S4), and the inductor current is checked and the UC link capacitor ( 170, it is checked whether or not the discharge (S5).

When the inductor current is checked and the discharge of the UC link capacitor 170 is confirmed (FIG. 3D), the lower elements Q4, Q5, and Q6 are also normal, so that the upper and lower IGBT elements are normal (S6). 3a, 3d).

On the other hand, when the check result of step S3, when the inductor current and the charge of the UC link capacitor 170 is not confirmed, it is checked whether the voltage of the DC link capacitor 150 changes (S7).

As a result of the check, if there is no voltage change of the DC link capacitor 150, it is determined that the upper elements Q1, Q2, and Q3 are open broken (S8, FIG. 3C), and if there is a voltage change of the DC link capacitor 150, It is determined that the elements Q4, Q5 and Q6 are short broken (S9, Fig. 3B).

When the inductor current and the discharge of the UC link capacitor 170 are not confirmed as a result of checking in step S5, it is checked whether the voltage of the DC link capacitor 150 is changed (S10).

As a result of the check (S10), if there is no voltage variation of the DC link capacitor 150, it is determined that the lower element (Q4, Q5, Q6) is an open damage (S11, Figure 3f), the voltage of the DC link capacitor 150 If there is a change, it is determined that the upper elements Q1, Q2, Q3 are short broken (S12, Fig. 3F).

Meanwhile, the case of the DC / AC inverter, that is, the engine auxiliary motor inverter 130 or the swing motor inverter 140 (Example 2) will be described.

FIG. 6 shows a detailed view when the power converter is a DC / AC inverter, that is, the engine auxiliary motor inverter 130 or the swing motor inverter 140.

As shown, the engine auxiliary motor inverter 130 or the swing motor inverter 140 is located between the DC link capacitor 150 and a three phase AC motor, such as an engine auxiliary motor or swing motor, and upsides such as a plurality of IGBTs. It consists of the power semiconductor elements Q1, Q2, Q3, and several lower power semiconductor elements Q4, Q5, Q6. Current transformers are arranged between the upper and lower semiconductor elements Q1, Q2, Q3 / Q4, Q5, and Q6 and the three-phase AC motor, and three inductors I1 are provided in the three-phase AC motor. , I2, I3).

When the power converter is a DC / AC inverter, ie, the engine auxiliary motor inverter 130 or the swing motor inverter 140, the power converter is checked as shown in Tables 3 and 4 below.

Short check
[Device driving sequence: Q1 & Q5, Q2 & Q6, Q3 & Q4] (1) Applying short (approximately several ON) pulses to the lower elements Q4, Q5, and Q6 in sequence - (2) DC link capacitor (150) voltage fluctuations without current sensing Upper element Short (3) Applying short (approximately several ON) pulses to the upper elements Q1, Q2, and Q3 in sequence - (4) DC link capacitor (150) voltage fluctuations without current sensing Lower element Short

Open Check
[Device driving sequence: Q1 & Q5, Q2 & Q6, Q3 & Q4] (1) Applying short (approximately several ON) pulses to the lower elements Q4, Q5, and Q6 in sequence - (2) No current sensing and no voltage fluctuation of the DC link capacitor 150 Upper element open (3) Applying short (approximately several ON) pulses to the upper elements Q1, Q2, and Q3 in sequence - (4) No current fluctuation and no DC link capacitor 150 voltage fluctuation Lower element open

At this time, in order to correspond to the structure of the three-phase motor, the pulse application order of the upper and lower semiconductor elements (Q1, Q2, Q3, Q4, Q5, Q6) is one of the upper and lower semiconductor elements, respectively, Q1 and Q5, Q2 and Q6, Q3 and After selecting in the same pair as Q4, the pulse is applied.

Hereinafter, referring to FIGS. 7A to 7C, a process of checking whether a semiconductor device is open or short when the power converter is a DC / AC inverter, that is, the engine auxiliary motor inverter 130 or the swing motor inverter 140, will be described. Explain.

7A to 7C illustrate examples of the Open Check / Short Check of Tables 3 and 4. As described in Table 3 and Table 4, Open Check / Short Check is performed by applying a short (about a few orders of magnitude) ON pulses in the order Q1 & Q5, Q2 & Q6, Q3 & Q4.

FIG. 7A illustrates the normal mode. When the ON pulse is applied to the upper element Q1 and the lower element Q5, the upper element Q1 and the current transformer CT3 are turned on from the DC link capacitor 150. A current flows through the inductor (coil) I2 of the AC motor, and then a current flows into the current transformer CT2 and the lower element Q5, and as a result, a change in the voltage of the DC link capacitor 150 occurs.

However, when the ON pulse is applied to the upper element Q1 and the lower element Q5 as shown in FIG. 7B, when the upper element Q2 or the lower element Q4 has a short failure, the upper element Q1 and the lower element Q1 are not. An arm short occurs between the lower element Q4 or between the upper element Q2 and the lower element Q5, and a large current flows, causing a voltage variation of the DC link capacitor 150, and the current transformers CT1 and CT2. , CT3) does not detect current and current does not flow through the inductor (coil) of the AC motor.

As shown in FIG. 7C, when the ON pulse is applied to the upper element Q1 and the lower element Q5, the upper and lower elements Q1 when the upper element Q1 and the lower element Q5 have an Open failure. , Q2, Q3 / Q4, Q5, and Q6), and there is no voltage fluctuation of the DC link capacitor 150.

8 is a flowchart illustrating a process of checking whether a semiconductor device is open or short when the power converter is a DC / AC inverter, that is, the engine auxiliary motor inverter 130 or the swing motor inverter 140.

When the test is started (S100), when the ON pulse is applied to the upper element Q1 and the lower element Q5 at the same time, a short ON pulse is applied (S200). Then, by checking the current of the current transformers CT2 and CT3, it is checked whether the AC motor is energized (S300). As a result of the check, when the currents of the current transformers CT2 and CT3 are confirmed, it is determined that the upper element Q1 and the lower element Q5 are normal (S400).

On the other hand, when the check result of step S300, if the current of the current transformer (CT2, CT3) is not confirmed, it is checked whether the voltage of the UC link capacitor 170 changes (S500). As a result of the check, when there is no voltage change of the UC link capacitor 170, it is determined that the upper element Q1 or the lower element Q5 has an open damage (S600), and there is a voltage change of the UC link capacitor 170. It is determined that the upper element Q1 or the lower element Q5 has a short break (S700).

FIG. 9 is a diagram illustrating a three-phase AC motor current waveform according to application of ON pulses of upper and lower semiconductor elements Q1, Q2, Q3 / Q4, Q5, and Q6.

As shown, when a driving pulse is simultaneously applied to the upper IGBT Q1 and the lower IGBT Q5 of the DC / AC inverter, that is, the engine auxiliary motor inverter 130 or the swing motor inverter 140, A phase current, that is, Current flows in the direction CT to the current transformer CT3 in the direction (+) to enter the AC motor, and current flows in the B phase current, that is, the current flow in the direction (-) to advance from the AC motor in the current transformer CT2 (see FIG. 7C).

The above description is merely illustrative of the present invention, and various modifications may be made by those skilled in the art without departing from the technical spirit of the present invention. Therefore, the embodiments disclosed in the specification of the present invention are not intended to limit the present invention. The scope of the present invention should be construed by the claims below, and all techniques within the scope equivalent thereto will be construed as being included in the scope of the present invention.

101: battery 102: excavator electric device
103: engine auxiliary motor 104: swing motor
105: ultracapacitor 100: power converter
120: logic control board 130: engine auxiliary motor inverter
140: swing motor inverter 150: DC link capacitor
160: ultracapacitor converter 170: UC link capacitor
Q1, Q2, Q3: upper semiconductor element (IGBT)
Q4, Q5, Q6: lower semiconductor element (IGBT)
CT, CT1, CT2, CT3: Current Transformers

Claims (6)

In a hybrid construction machine having an engine auxiliary motor, a load motor, and an electric system for starting the engine, the plurality of upper semiconductor switches Q1, Q2, Q3 and the plurality of lower semiconductor switches Q4, Q5, Q6 are connected. In the safe driving method of the power conversion device for a hybrid construction machine provided,
Applying a signal sequentially or simultaneously to any one of the upper semiconductor switches (Q1, Q2, Q3) and any one of the lower semiconductor switches (Q4, Q5, Q6) before activation of the electrical system;
A current checking step of checking whether current flows from one end of the power converter to the other end or from the other end of the power converter; And
When the current flows from one end of the power conversion device to the other end or the other end, it is determined to be normal to activate the electrical system, and when the current does not flow from one end of the power conversion device to the other end or the other end, An abnormality determination step of judging at least one or more of the semiconductor switches Q1, Q2 and Q3 and the lower semiconductor switches Q4, Q5 and Q6;
Including,
The signal applying step,
An upper applying step of sequentially applying signals to the upper semiconductor switches Q1, Q2, and Q3, respectively; And
A lower applying step of sequentially applying signals to the lower semiconductor switches Q4, Q5, and Q6 after the upper applying step, respectively.
Safe drive method of a power conversion device for a hybrid construction machine comprising a. The method of claim 1,
One end of the power converter is connected to a DC link capacitor, the other end of the power converter is connected to an ultracapacitor (UC) link capacitor,
The abnormality determination step,
When no current flows from one end to the other end or the other end of the power converter, the upper semiconductor switch Q1, Q2, and Q3 is checked by checking whether the UC link capacitor is charged or discharged and whether the DC link capacitor voltage is changed. Or a lower one or more of the lower semiconductor switches (Q4, Q5, Q6) of the open or short. In a hybrid construction machine having an engine auxiliary motor, a load motor, and an electric system for starting the engine, the plurality of upper semiconductor switches Q1, Q2, Q3 and the plurality of lower semiconductor switches Q4, Q5, Q6 are connected. In the safe driving method of the power conversion device for a hybrid construction machine provided,
Applying a signal sequentially or simultaneously to any one of the upper semiconductor switches (Q1, Q2, Q3) and any one of the lower semiconductor switches (Q4, Q5, Q6) before activation of the electrical system;
A current checking step of checking whether current flows from one end of the power converter to the other end or from the other end of the power converter; And
When the current flows from one end of the power conversion device to the other end or the other end, it is determined to be normal to activate the electrical system, and when the current does not flow from one end of the power conversion device to the other end or the other end, An abnormality determination step of judging at least one or more of the semiconductor switches Q1, Q2 and Q3 and the lower semiconductor switches Q4, Q5 and Q6;
Including,
The signal applying step,
After selecting each one of the upper semiconductor switch (Q1, Q2, Q3) and the lower semiconductor switch (Q4, Q5, Q6), the signal is applied to the selected upper semiconductor switch and the selected lower semiconductor switch simultaneously. Safe driving method of power converter for hybrid construction machinery. The method of claim 3,
The power conversion device is connected at one end to the DC link capacitor and at the other end to the engine auxiliary motor or the load motor;
The abnormality determination step,
When the current does not flow in the engine auxiliary motor or the load motor, the DC link capacitor voltage is checked to determine whether the selected upper semiconductor switch and the selected lower semiconductor switch or the selected upper semiconductor switch and the selected lower semiconductor switch A method for safely driving a power conversion device for a hybrid construction machine, characterized in that it is determined as more than an open or a short of the connected upper semiconductor switch and the lower semiconductor switch. The method according to any one of claims 1 to 4,
If it is determined that at least one or more of the upper semiconductor switch (Q1, Q2, Q3) and the lower semiconductor switch (Q4, Q5, Q6) is not connected to the power converter and the ultra capacitor (UC) link capacitor, Safe driving step of not applying a gate driving pulse signal to the upper semiconductor switch (Q1, Q2, Q3) and the lower semiconductor switch (Q4, Q5, Q6)
Safe drive method of the power conversion device for a hybrid construction machine further comprising.
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