KR20090069719A - Hybrid load control method and system for heavy equipment - Google Patents

Abstract

A method for controlling hybrid load of heavy equipment and a system using the same are provided to optimize power distribution to a motor/generator and a rotation motor while driving an engine with optimal efficiency. A method for controlling hybrid load of heavy equipment comprises the following steps of: calculating whole load amount related to output of the heavy equipment; measuring storage capacity of a capacitor(22); selecting a predetermined control map for output load based on the storage capacity of the capacitor; and determining output quantity of the capacitor and an engine(14) by applying the whole load amount measured in the selected map.

Description

Hybrid load control method and system to which the method is applied {Hybrid load control method and system for heavy equipment}

The present invention relates to a hybrid load control method for heavy equipment and a system to which the method is applied, and more particularly, to allow the power distribution to be optimally performed between the motor / generator and the turning motor while allowing the engine output to operate at an optimum efficiency. The present invention relates to a hybrid load control method of heavy equipment and a system to which the method is applied to increase energy use efficiency.

Various types of mechanical equipment or heavy equipment (hereinafter referred to as construction machinery) are used in construction and civil engineering sites.

Excavator, one of the construction machines, uses a bucket to dig or transport the ground, removes the bucket as necessary, and mounts a special purpose attachment instead, and performs various tasks.

Hereinafter will be described assuming an excavator as a representative heavy equipment.

On the other hand, the internal combustion engine is mainly used as a power source for heavy equipment.

Among various heavy equipments, especially hydraulic excavators operate the internal combustion engine at a constant speed to operate the pump continuously, but the load fluctuation during the operation causes a large fluctuation in the output of the internal combustion engine.

In other words, in the internal combustion engine of the hydraulic excavator, the fuel consumption can be reduced when a certain output is made in a region in which the efficiency of the output is good, but the working load fluctuation of the hydraulic excavator is severe and practically impossible.

This is, after all, expected to be due to the fact that the engine power is not operated at optimum efficiency in the entire system, so a countermeasure is required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a hybrid load control method for heavy equipment that can increase energy use efficiency by allowing power distribution to be optimally made to a motor / generator and a swinging motor while allowing an engine output to be operated at an optimum efficiency. To provide a system.

The technical problem to be achieved by the present invention is not limited to the technical problem mentioned above, another technical problem that is not mentioned can be clearly understood by those skilled in the art from the following description. There will be.

Hybrid load control method of a heavy equipment according to an embodiment of the present invention for achieving the technical problem, the step of calculating the total load required in relation to the output of the heavy equipment (a); Measuring the amount of storage of the capacitor 22 (b); (C) selecting a predetermined control map for an output load based on the capacitance of the capacitor (22); And (d) determining the output of the engine 14 and the output of the capacitor 22 to be output by applying the total load calculated in the selected map.

Here, the total load amount calculated in the step (a) is the load amount of the sum of the pump 12 load and the swing motor 20 load, the power required to generate and drive the motor 16 / generator 18, and The converter efficiency and the like can be calculated by the sum of the loads determined as spare loads.

The control map may be three types of maps in which the amount of power storage in the capacitor 22 is 90% or more, the amount of power storage is 90-40%, and the state of power storage is 40% or less.

In the three maps, the storage amount of the capacitor 22 is selected based on the instantaneous maximum storage capacity of the capacitor 22, and the discharge amount output by the capacitor 22 is the maximum instantaneous capacity of the capacitor 22. It may be selected based on the discharge possible amount.

On the other hand, the object, the engine 14 is connected to the pump 12 for driving the actuator 10; A motor (16) / generator (18) connected in parallel with the engine (14) to drive the pump (12); A capacitor (22) connected to the motor (16) / generator (18) for charging or discharging energy based on any one operation selected from the motor (16) / generator (18); A swing motor 20 provided independently of the engine 14 and connected to the capacitor 22; And calculating the total load required in relation to the output of the heavy equipment, measuring the capacitance of the capacitor 22, and then determining a predetermined control map for the output load based on the capacitance of the capacitor 22. And a control unit (not shown) for controlling the engine 14 output amount and the capacitor 22 output amount to be output by applying the total load amount calculated in the selected map. It is also achieved by a hybrid load control system.

Here, the motor 16 / generator 18 and the capacitor 22 are connected via a first converter 24, the turning motor 20 and the capacitor 22 is connected to the second converter 26. Can be connected via.

The control unit charges energy to the capacitor 22 through the first converter 24 when the motor 16 / generator 18 operates as the generator 18, and the motor 16 / generator ( 18 may be controlled to receive energy from the capacitor 22 through the first converter 24 when the motor 16 operates.

The control unit charges energy to the capacitor 22 through the second converter 26 when the swing motor 20 is regenerated, and the capacitor 22 or the motor when the swing motor 20 is operated. (16) / generator 18 can be controlled to receive the energy.

The total load amount may include a load amount obtained by adding up the load of the pump 12 and the load of the swing motor 20, the power required to generate and drive the motor 16 / generator 18, and the first and second converters. (24,26) can be calculated by the sum of loads determined as efficiency loads.

The control map may be three types of maps in which the amount of power storage in the capacitor 22 is 90% or more, the amount of power storage is in the range of 90-40%, and the state in which the power storage is 40% or less.

In the three maps, the storage amount of the capacitor 22 is selected based on the instantaneous maximum storage capacity of the capacitor 22, and the discharge amount output by the capacitor 22 is the maximum instantaneous capacity of the capacitor 22. It may be selected based on the discharge possible amount.

Specific details of other embodiments are included in the detailed description and the drawings.

According to the present invention, while the engine output is operated at the optimum efficiency, the power distribution can be optimally made to the motor / generator and the swing motor to increase the energy use efficiency.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a block diagram of a hybrid load control system for heavy equipment according to an embodiment of the present invention, Figure 2 is a flow chart for a hybrid load control method for heavy equipment according to an embodiment of the present invention, Figure 3 is a speed and torque of the engine (torque) map, Figure 4 is a load control map according to the amount of capacitor storage capacity (cap), when the capacitance of the capacitor is more than 90%, Figure 5 is a load control map (map) according to the amount of capacitor storage FIG. 6 is a diagram illustrating a case where a capacitance of a capacitor is between 90% and 40%, and FIG. 6 is a diagram of a case where a capacitance of a capacitor is 40% or less as a load control map according to the amount of capacitor storage.

Prior to the description with reference to the drawings, the load control method of the present embodiment and the system to which the method is briefly described further, the present embodiment recovers a large amount of energy that is instantaneously regenerated from the turning motor 20 to efficiently use the energy. In addition, while the engine 14 outputs a constant output in the high efficiency region, the remaining or insufficient power is used to replenish or store energy from the capacitor 22 through the motor 16 / generator 18.

In other words, the driving of the engine 14 is controlled in a region where the efficiency is high, and the fuel consumption is reduced by using the motor 16 / generator 18 for a portion or a small output.

In addition, by recovering the energy regenerated from the swing motor 20 to increase the energy use efficiency.

Through such a load control method and a system to which the method is applied, the output of the engine 14, the motor 16 / generator 18 and the turning motor 20 is determined according to the energy storage state in the entire system to supply energy to the power system. It can be used efficiently.

In other words, it is possible to improve the energy use efficiency by allowing the power distribution to be optimally made to the motor 16 / generator 18 and the turning motor 20 while allowing the engine 14 to operate at the optimum efficiency. .

For reference, the hybrid load control system of this embodiment can be used for all heavy equipment equipped with the configuration as shown in FIG.

However, hereinafter, the excavator will be described as an example for convenience of description.

As shown in FIG. 1, the hybrid load control system according to the present embodiment includes an engine 14 connected to a pump 12 for driving an actuator 10 and a pump connected in parallel with the engine 14. A motor 16 / generator 18 that drives 12 and a motor 16 / generator 18 that are connected to and charge energy based on an action selected from one of the motor 16 / generator 18. Or a discharging output capacitor 22, a turning motor 20 provided independently of the engine 14 and connected to the capacitor 22, and a control unit (not shown) for controlling them.

The actuator 10 is a part that is operated for the operation of heavy equipment.

For example, when the heavy equipment is an excavator, the actuator 10 becomes a part for driving an excavating bucket or a boom.

The pump 12 serves to pump a working fluid such as hydraulic pressure to the actuator 10, for example.

The engine 14 is a part which drives the pump 12 substantially, and is a part responsible for a main output.

And the turning motor 20 is also a component that is driven independently of the engine 14.

The capacitor 22 is a so-called capacitor, and serves as a battery that can be output as energy is charged or discharged.

For reference, the reason why the capacitor 22 is used instead of the battery in the compound type hybrid excavator as in the present embodiment is that the time taken for the capacitor 22 to be charged and discharged is considerably shorter than that of the battery. This is because the life of the capacitor 22 is long even if the number of charges and discharges is frequent.

In the case of lithium ion batteries, their lifespan is reduced by frequent rapid charge or rapid discharge.

Compound-type excavators often charge or discharge large amounts of energy instantaneously due to large variations in workload during operation.

Therefore, it cannot be used for a long time when the lithium ion battery is applied to the compound type hybrid excavator.

Therefore, in the compound type hybrid excavator as in the present embodiment, the capacitor 22 is used as an auxiliary storage battery in order to recover regenerative energy and increase energy efficiency.

A first converter 24 is connected to the motor 16 / generator 18 and the capacitor 22, and a second converter 26 is connected to the turning motor 20 and the capacitor 22.

In the region of the first converter 24, a discharge resistor 28 is interposed.

The discharge resistor 28 serves to release energy when the regeneration of the capacitor 22 is impossible.

On the other hand, the control unit charges energy to the capacitor 22 through the first converter 24 when the motor 16 / generator 18 operates as a generator 18, the motor 16 / generator 18 is a motor In operation (16), the first converter 24 controls to receive energy from the capacitor 22 through the tube.

In addition, the control unit charges energy to the capacitor 22 through the second converter 26 in the regeneration of the swing motor 20, and the capacitor 22 or the motor 16 / generator ( 18) control to receive energy from

In particular, when power is insufficient, the motor 16 / generator 18 is driven by the generator 18 and serves to supply energy to the turning motor 20.

In particular, the controller of the present embodiment calculates the total load required in relation to the output of the excavator, measures the amount of storage of the capacitor 22, and then determines a predetermined amount of the output load based on the amount of storage of the capacitor 22. The control map is selected and then the total load calculated from the selected map is applied to control the engine 14 to be output and the capacitor 22 to be output.

At this time, the total load amount calculated is the load amount obtained by adding up the load of the pump 12 and the turning motor 20, the power required when the motor 16 / generator 18 is driven to generate power, and the first and second converters. (24,26) It is calculated by the sum of loads that determine efficiency and the like as marginal loads.

And the control map is 3 in the state where the electric storage amount is 90% or more (refer FIG. 4), the electric storage amount is 90-40% (refer FIG. 5), and the electric storage amount is 40% or less (refer FIG. 6) in the capacitor 22 Branch map.

In these three maps, the storage capacity of the capacitor 22 is selected based on the instantaneous maximum power storage capacity of the capacitor 22, and the discharge amount output by the capacitor 22 is based on the instantaneous maximum discharge capacity of the capacitor 22. Is selected.

A brief description of the power driving method for the compound type hybrid excavator having such a configuration is as follows.

First, as shown in FIG. 3, the pump 12 is driven by selecting a high-efficiency region (the highest efficiency region of the engine 14) in the engine 14 so that the output of the engine 14 is constantly output in a high-efficiency region. do.

At this time, if the power of the engine 14 is insufficient, the motor 16 / generator 18 is driven by the motor 16 to assist energy, and if the power remains, the motor 16 / generator 18. Is driven by the generator 18 to store energy in the capacitor 22.

At this time, the driving method of the engine 14 output and the motor 16 / generator 18 is selected according to the amount of energy accumulated in the capacitor 22.

Since the regeneration energy is large in the case of the revolving motor 20, only the revolving motor 20 is separated and driven by the motor 16 / generator 18 to regenerate the regenerated energy in the capacitor 22 and the revolving motor 20 ), Energy is used for the capacitor 22.

Meanwhile, referring to FIG. 2, the hybrid load control method for heavy equipment according to an embodiment of the present invention will be described.

First, the total load required for the output of the excavator is calculated (S11).

At this time, the total load amount is the load amount obtained by adding up the load of the pump 12 and the turning motor 20, the power required when the motor 16 / generator 18 is driven to generate power, and the first and second converters 24. Can be calculated by the sum of the loads determined as efficiency loads.

Next, the electrical storage amount of the capacitor 22 is measured (S13).

Then, a predetermined control map for the output load is selected based on the capacitance of the capacitor 22 (S15).

As described above, the control map has a state in which the amount of power storage in the capacitor 22 is 90% or more (see FIG. 4), a state in which the amount of power storage is between 90-40% (see FIG. 5), and a state in which the amount of power storage is 40% or less (FIG. Three maps).

In other words, FIG. 4 is a map to be used when the capacitor 22 is substantially full, and FIG. 5 is a map to be used when the capacitor 22 is properly charged, and FIG. 6 is a map of the capacitor 22. This is the map that will be used when the storage capacity is almost used up.

In these three maps, the storage capacity of the capacitor 22 is selected based on the instantaneous maximum power storage capacity of the capacitor 22, and the discharge amount output by the capacitor 22 is based on the instantaneous maximum discharge capacity of the capacitor 22. Is selected.

Next, the total load amount calculated in the map selected from FIGS. 4 to 6 is applied to determine the engine 14 output amount and the capacitor 22 output amount to be output (S17), and the determined ones are applied.

After application, if the operation of the engine 14 is stopped (S19), it is fed back to the beginning.

For reference, in the above description, the total capacitance is calculated and then the capacitance of the capacitor 22 is measured. However, these may proceed in parallel with each other.

As such, according to the present embodiment, the engine 14 output is operated at the optimum efficiency while the power distribution can be optimally made to the motor 16 / generator 18 and the turning motor 20 so as to use energy efficiency. To increase.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains can understand that the present invention can be implemented in other specific forms without changing the technical spirit or essential features. will be.

Therefore, the embodiments described above are to be understood as illustrative and not restrictive in all respects, and the scope of the present invention is represented by the following detailed description, and the meaning and scope of the claims and All changes or modifications derived from the equivalent concept should be interpreted as being included in the scope of the present invention.

Hybrid load control method of the heavy equipment according to an embodiment of the present invention and the system to which the method is applied, can be applied to a variety of heavy equipment, including excavators. In particular, it is possible to increase the energy use efficiency by allowing the power output to be optimally made to the motor / generator and the turning motor while allowing the engine output to operate at the optimum efficiency.

1 is a block diagram of a hybrid load control system of heavy equipment according to an embodiment of the present invention.

2 is a flowchart illustrating a hybrid load control method for heavy equipment according to an embodiment of the present invention.

3 is a map of the speed and torque of the engine.

FIG. 4 is a load control map according to the amount of capacitor storage, in which the amount of storage of the capacitor is 90% or more.

FIG. 5 is a load control map according to the amount of capacitor storage, in which the amount of storage of the capacitor is between 90 and 40%.

FIG. 6 is a load control map according to the amount of capacitor storage, in which the amount of storage of the capacitor is 40% or less.

* Explanation of symbols for the main parts of the drawings

10: actuator 12: pump

14 engine 16,18 motor / generator

20: turning motor 22: capacitor

24, 26: first and second converter 28: discharge resistance

Claims (6)

(A) calculating a total load required in relation to the output of the heavy equipment; Measuring the amount of storage of the capacitor 22 (b); (C) selecting a predetermined control map for an output load based on the capacitance of the capacitor (22); And And (d) determining the output of the engine and the output of the capacitor to be output by applying the total load calculated in the selected map. The method of claim 1, The total load amount calculated in the step (a) is a load amount obtained by adding the pump 12 load and the swing motor 20 load, and the power and converter efficiency required when generating and driving the motor 16 / generator 18. Hybrid load control method for heavy equipment, characterized in that calculated by the sum of the load amount determined as the marginal load. The method according to claim 1 or 2, The control maps are three kinds of maps in which the amount of power storage in the capacitor 22 is 90% or more, the amount of power storage is 90-40%, and the state of power storage is 40% or less, In the three maps, the storage amount of the capacitor 22 is selected based on the instantaneous maximum storage capacity of the capacitor 22, and the discharge amount output by the capacitor 22 is the maximum instantaneous capacity of the capacitor 22. Hybrid load control method of heavy equipment, characterized in that selected based on the discharge possible amount. An engine 14 connected to a pump 12 for driving the actuator 10; A motor (16) / generator (18) connected in parallel with the engine (14) to drive the pump (12); A capacitor (22) connected to the motor (16) / generator (18) for charging or discharging energy based on an operation of any one selected from the motor (16) / generator (18); A swing motor 20 provided independently of the engine 14 and connected to the capacitor 22; And The total load required for the output of the heavy equipment is calculated, the amount of storage of the capacitor 22 is measured, and a predetermined control map for the output load is calculated based on the amount of storage of the capacitor 22. And a controller (not shown) for controlling to determine the engine 14 output and the capacitor 22 output to be output by applying the total load calculated in the selected map after selection. Load control system. The method of claim 4, wherein A first converter 24 is connected to the motor 16 / generator 18 and the capacitor 22, A second converter 26 is connected to the turning motor 20 and the capacitor 22, The control unit charges energy to the capacitor 22 through the first converter 24 when the motor 16 / generator 18 operates as the generator 18, and the motor 16 / generator ( 18 controls the first converter 24 to receive energy from the capacitor 22 through the first converter 24 when the motor 16 operates, while the second converter (when regenerating the turning motor 20). 26 is charged to the capacitor 22 and controlled to receive energy from the capacitor 22 or the motor 16 / generator 18 during operation of the swing motor 20. Hybrid load control system for heavy equipment. The method according to claim 4 or 5, The total load amount may include a load amount obtained by adding up the load of the pump 12 and the load of the swing motor 20, the power required to generate and drive the motor 16 / generator 18, and the first and second converters. (24,26) is calculated by the sum of loads that determine efficiency, etc. as spare load, The control map is three maps in which the amount of power storage in the capacitor 22 is 90% or more, the amount of power storage is between 90-40%, and the state of power storage is 40% or less, In the three maps, the capacitance of the capacitor 22 is selected based on the instantaneous maximum capacitance of the capacitor 22, and the discharge amount output by the capacitor 22 is the maximum moment of the capacitor 22. Hybrid load control system for heavy equipment, characterized in that selected based on the discharge possible amount.

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