CN101590850B - A power control method for a tracked hybrid vehicle - Google Patents

Abstract

The invention relates to a power control method of a crawler-type hybrid electric vehicle, in particular to crawlers which adopt hybrid power supply of an engine-generator set and power batteries and also adopt two electric motors to drive the driving wheels at two sides respectively. The invention provides a method for coordinately controlling the output power of the engine and the power batteries according to the accelerator pedal signals, engine speed and speed signals of electric motors at two sides in order to effectively utilize the power provided by the engine-generator set and power batteries. The method comprises the following steps: determining the power required by vehicles and the power which can be provided by the engine-generator set, obtaining the power required by the power batteries, determining the target output current of the batteries according to the mode of batteries and bus voltage and realizing the output of the required power by controlling the magnitude of current of a direct current converter; The method further comprises the following steps: when judging that the power required by the vehicles is greater than the sum of the power provided by the engine-generator set and power batteries, restricting the power output of the driving motors at two sides to be the sum of the power provided by the engine-generator set and power batteries.

Description

A power control method for a tracked hybrid vehicle

technical field

The invention relates to a crawler-type hybrid vehicle, in particular to a crawler vehicle which uses an engine-generator set and a power battery pack to provide power, and uses two electric motors to respectively drive driving wheels on both sides. In particular, the present invention relates to a method for coordinated control of the output power of the engine-generator set and the power battery pack according to the accelerator pedal signal, the engine speed, and the double-side motor speed signals.

Background technique

With the advancement of science and technology, the development of technologies such as high-power power electronic devices is very rapid, and the application advantages of electric drive technology on tracked vehicles are becoming more and more obvious. A tracked vehicle using electric transmission technology has an engine-generator set, a power battery pack, and an electric motor at the same time, and it is necessary to realize the power and economy of the vehicle through coordinated control of multiple power components. Therefore, the power control of hybrid tracked vehicles Method or strategy is a very critical issue.

Although the coordinated power control of traditional power components applied to wheeled hybrid vehicles, such as engine-generator sets, power battery packs and electric motors, has been developed to a certain extent, due to the fundamental nature of the running mechanism of tracked vehicles and wheeled vehicles The difference makes it very difficult to apply the power control method directly from the hybrid wheeled vehicle to the tracked vehicle.

In the following document 1, it is disclosed that a tracked hybrid vehicle adopts an engine-generator set and a power battery pack to provide electric energy, and the power battery pack can controlly output electric energy, and two electric motors convert electric energy into mechanical energy, and drive the two sides respectively The driving wheels and tracks realize the driving of the vehicle, and then determine the control methods of several working modes of the engine-generator set and the power battery pack according to different operating conditions and driving requirements. However, document 1 does not address the power control issues related to the engine-generator set and power battery pack providing power, and the electric motor consuming power. No other prior art discloses a power control method for a tracked hybrid vehicle, so that the tracked vehicle has high power performance and economical performance.

Document 1: Publication number: CN1944139A.

Contents of the invention

Aiming at the deficiencies of the prior art, the invention discloses a power control method for a crawler-type hybrid vehicle, which is suitable for driving the driving wheels of the crawlers on both sides respectively by dual motors. The power control unit integrates the status of each component of the vehicle and the driving conditions of the vehicle, and reasonably distributes the driving power between the engine-generator set and the power battery pack, so that the two energy sources, the engine-generator set and the power battery pack, work in the high-efficiency area , so that the vehicle can improve fuel economy and prolong the cycle life of the power battery under the premise of ensuring power.

The present invention provides a method for power control of a tracked hybrid vehicle, wherein the crawlers on both sides of the tracked hybrid vehicle are independently driven by a motor I and a motor II, and the vehicle is equipped with an engine-generator set and an energy storage device jointly constituted power output components, wherein an engine drives a generator to constitute the engine-generator set, the control method implements control of power supply from the power output components to the electric motor I and the electric motor II, and the control method Has the following steps:

a. Determine the required power of the vehicle, which is the sum of the target operating powers of the electric motor I and the electric motor II;

b. Determine the maximum output power of the engine-generator set;

c. Determine the maximum output power of the energy storage device;

d. Compare the sum of the target operating power of the motor I and the motor II with the sum of the maximum output power of the current engine-generator set and the maximum output power of the energy storage device, and take the smaller one as the required power of the vehicle;

The vehicle also has a power control unit that implements the control of power supply from the power output components to the electric motor I and the electric motor II:

The power control unit has a storage unit, which stores the optimal fuel consumption curve of the engine-generator set, and the step b also includes measuring the actual rotational speed of the engine, and the maximum output power of the engine-generator set is at the The engine power value corresponding to the actual speed on the optimal fuel consumption curve.

Preferably, it also includes the step of determining the target speed of the engine, taking the engine speed corresponding to the value of the required power of the vehicle on the optimal fuel consumption curve of the engine-generator set as the target speed of the engine.

Preferably, if the required power of the vehicle is not in the power range corresponding to the optimal fuel consumption curve of the engine-generator set, the engine speed corresponding to the power at the point closest to the vehicle required power on the optimal fuel consumption curve of the engine-generator set is taken as the target engine speed.

Preferably, it also includes the step of determining the target output power of the energy storage device, where the target output power of the energy storage device is equal to the difference between the required power of the vehicle and the maximum output power of the engine-generator set;

It also includes resetting the maximum output power of the energy storage device to the target output power of the energy storage device if the maximum output power of the energy storage device is less than the target output power of the energy storage device when the energy storage device is outputting power.

Preferably, the energy storage device is a battery pack, a capacitor or a combination of both;

The vehicle also includes a voltage converter through which the energy storage device is connected to the electric motor I and the electric motor II;

The voltage converter can apply the voltage of the energy storage device to the electric motor I and the electric motor II in a variable manner;

The voltage converter is a DC voltage converter;

The vehicle also includes a rectifier, which is used to rectify the alternating current output by the engine-generator set into direct current, and output the direct current to the electric motor I and the electric motor II;

The target output power of the energy storage device is divided by the output voltage of the rectifier to obtain the target output current of the energy storage device. The DC voltage converter also has a control unit, which controls the output current of the energy storage device.

The power control method of the tracked vehicle is: firstly determine the total required power of the motor I and the motor II, that is, the required power of the vehicle, and then determine the sum of the maximum output power of the engine-generator set and the maximum output power of the energy storage device. When the sum of the above powers is greater than When the vehicle requires power, reset the required power of the vehicle to the sum of the above powers, that is, the control method based on the required power of the vehicle,

The method includes determining the required power of the vehicle and the maximum output power that can be provided by the engine-generator set, then obtaining the target output power of the power battery pack, determining the output current of the power battery pack according to the state of the battery pack and the bus voltage, and controlling the current flow of the DC converter. control to achieve this power output.

The method also includes limiting the power output of the driving motors on both sides to the sum of the maximum power of the engine-generator set and the power battery set when it is judged that the required power of the vehicle is greater than the sum of the maximum output power of the engine-generator set and the power battery set. When it is judged that the output power of the power battery pack is greater than the peak power of the current state of the power battery pack, the output power of the power battery pack is limited so that it is not greater than the peak power.

Description of drawings

Accompanying drawing 1 is a kind of schematic diagram of application track type hybrid vehicle of the present invention and its control system,

Figure 2 is a control flow diagram describing the present invention.

In the picture:

1-Accelerator pedal, 2-Power control unit, 3-Side reducer and driving wheel I, 4-Drive motor I, 5-Drive motor I control unit, 6-Drive motor II control unit, 7-Drive motor II, 8 - side reducer and driving wheel II, 9- power battery pack, 10- DC converter, 11- DC converter control unit, 12- DC bus, 13 engine-generator set, 13a- rectifier, 14- engine control unit, 15-CAN communication bus.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

FIG. 1 is a block diagram of a tracked hybrid vehicle to which the power control method of the present invention is applied. This structure is a further improvement on the vehicle structure of Document 1 in the background art of the present invention. Tracked hybrid vehicle, which has crawlers located on both sides of the vehicle, and the crawlers on both sides are driven by a driving wheel separately, and the electric motor I4 and the electric motor II7 are respectively arranged on both sides of the vehicle, wherein the electric motor I4 is arranged on the left side of the vehicle , the motor II7 is arranged on the right side of the vehicle, the above-mentioned motors can also be arranged in the following manner, the motor I4 is arranged on the right side of the vehicle, and the motor II7 is arranged on the left side of the vehicle; but in order to describe the embodiment of the present invention more clearly, in In the following description, it is uniformly stipulated that the electric motor I4 is arranged on the left side of the vehicle, and the electric motor II7 is arranged on the right side of the vehicle.

The motor I4 is connected to the driving wheel on the left through a mechanical structure, and then drives the left crawler, and the motor II7 is connected to the driving wheel on the right through a mechanical structure, and then drives the right crawler. The above-mentioned mechanical structure can be a side reducer, but it can also be Omit the above-mentioned side speed reducer according to the performance of the motor; the above-mentioned driving wheel on the left side and the speed reducer connected therewith constitute the side speed reducer and the driving wheel 1 in the accompanying drawing 1 together, and the driving wheel on the right side and the speed reducer connected thereto The speed reducer together constitutes the side speed reducer and the driving wheel 2.

The vehicle also has a power output component for supplying electric energy, ie power, to the electric motor I4 and the electric motor II7.

The power take-off unit consists of two parts:

A part of them has an engine, and a generator mechanically connected with the engine, and the engine and the generator together constitute the engine-generator set 13;

The other part is composed of an energy storage device, preferably, the energy storage device is composed of a battery pack, especially a power battery pack 9 .

Normally, the power battery pack outputs direct current, and the engine-generator set 13 outputs alternating current, and the engine-generator set 13 is also connected with a rectifier 13a, which is used to rectify the alternating current output by the engine-generator set 13 into direct current, so as to be compatible with the power The battery packs 9 are connected in parallel. In the case of this connection, the engine-generator 13 and the rectifier 13a jointly constitute the engine-generator-rectifier assembly, and the DC bus 12 is connected to the motor I4 and the motor II7 for providing power to the motor I4 and the motor II7. The electric motor II7 provides power, and the power battery pack 9 and the engine-generator-rectifier assembly are jointly connected on the DC bus 12; under this connection structure, when the electric energy of the power battery pack 9 is low, the motor-generator-rectifier assembly The assembly charges the power battery pack 9 .

In order to control the output voltage of the power battery pack 9, the power battery pack 9 is connected to the DC bus 12 through the DC converter 10. Under this connection structure, the output voltage of the power battery pack 9 is controllably connected to the motor I4 and the motor II7, At the same time, it is matched with the engine-generator-rectifier assembly 13, so that power can be provided to the power battery pack 9 more efficiently while protecting the service life of the power battery pack 9.

The DC converter 10 is preferably a DC voltage converter.

The above-mentioned engine also has an engine control unit 14, the motor I4 also has a motor I controller 5, the motor II7 also has a motor II controller 6, the DC converter 10 has a DC converter control unit 11, and the vehicle also has a power control unit 2, The power control unit 2 receives signals from the accelerator pedal 1, the DC converter control unit 11, the engine control unit 14, the controller 5 and the controller 6, such as the motor speed, the engine speed, the pedal rotation angle, the transformation ratio of the DC converter etc., the power control unit 2 also sends control signals to the DC converter control unit 11, the engine control unit 14, the controller 5 and the controller 6, such as motor target speed, motor target torque, motor target power, engine target speed, engine The transmission of the above-mentioned sending and receiving signals such as target power, engine target torque, and DC converter target transformation ratio can be transmitted through the CAN communication bus 15 .

Power control unit 14 has the microprocessor with CPU as the core, and it also has storage unit, in this storage unit, is stored the minimum fuel consumption curve of engine-generator set, and its storage mode is, at first engine-generator set The corresponding relationship between the engine speed on the minimum fuel consumption curve of the engine and the output power of the engine-generator set is established, and then the database is stored in the memory; the minimum fuel consumption curve of the engine-generator set can be obtained by conventional test methods , on the minimum fuel consumption curve, there is a corresponding relationship between the rotational speed of the engine and the output power of the engine-generator set, and the way to obtain the minimum fuel consumption curve is not within the scope of the present invention, and will not be described in detail here; the storage unit also stores The corresponding relationship of the output parameters of the generator, in this corresponding relationship, there is a corresponding change curve of the output voltage and current of the generator at different engine speeds, preferably, since the output voltage and current of the generator are rectified by the rectifier 13a, Therefore, the above corresponding change curves can be converted into corresponding change curves of the output current and voltage of the rectifier, that is, the corresponding change curves of the output current and voltage of the rectifier at different engine speeds can be obtained through conventional test and calculation methods.

The power control unit 2, the drive motor I4 control unit 5, the drive motor II7 control unit 6, the engine control unit 14, and the DC converter control unit 11 are preferably microprocessor-based control devices known in the prior art. The power control unit 2 receives the rotation angle position from the accelerator pedal 1 through traditional electrical signals, and receives the rotational speed feedback signals from the driving motor I4 control unit 5 , the driving motor II7 control unit 6 , and the engine control unit 14 through the CAN communication bus 15 .

The accelerator pedal 1 controls the operation of the engine through the power control unit 2 , and its control signal is transmitted through the communication bus 15 .

Normally, the rectifier can convert the alternating current output by the engine-generator into direct current with high efficiency. In order to describe the embodiment of the present invention more clearly, the conversion loss of the rectifier 13a is ignored, that is, the conversion efficiency of the rectifier is 100%, so , the power provided by the engine-generator set 13 to the DC bus through the rectifier 13a is equal to the power provided by the engine-generator set 13, that is, at any moment, if the power provided by the engine-generator set 13 is W, the engine-generator-rectifier The power provided by the assembly is also W; but those skilled in the art know that in actual application, those skilled in the art can easily obtain the conversion efficiency of the rectifier 13a under different operating conditions through conventional test methods, and then through the engine- The power provided by the generator set 13 obtains the power provided by the engine-generator-rectifier assembly. Therefore, in the following description of the power control method of the tracked vehicle, the power provided by the engine-generator set in the embodiment is replaced by the engine- The power provided by the generator-rectifier assembly, or replacing the power output by the engine-generator set with the power output by the engine-generator-rectifier assembly also falls within the description scope of this embodiment.

Accompanying drawing 2 is the flowchart describing the control procedure of the present invention.

In step 20, the actual rotational speeds of motor I and motor II are transmitted to the power control unit 2 through the CAN communication bus 15, and the power control unit 2 obtains motor I by multiplying the actual rotational speeds of the two motors with the target operating torques of the two motors respectively. and the target operating power of the motor II, then the power control unit sends the target operating power of the motor I and the motor II to the drive motor I control unit 5 and the drive motor II control unit 6 through the CAN communication bus 15; The target operating torque can be obtained according to the environment in which the vehicle is used and the driver's input information, for example, the rotation angle of the accelerator pedal and the position of the steering wheel are used to determine the target operating torque of the electric motor I and the electric motor II, but the method of determination is a technical skill in the art Contents well known to those who are outside the scope of the present invention will not be described in detail here. The sum of the target operating power of the electric motor I and the electric motor II is regarded as the required power of the vehicle.

In step 21, the power control unit 2 has a storage unit, which stores the minimum fuel consumption curve of the engine-generator set, and the engine speed corresponding to the value of the required power of the vehicle on the engine-generator optimal fuel consumption curve is used as the engine target speed, The power control unit 2 sends the target rotational speed to the engine control unit 14 through the CAN communication bus 15 . If the required power of the vehicle is not in the power range corresponding to the engine-generator optimal fuel consumption curve, the engine target speed is taken as the rotational speed corresponding to the closest point on the engine-generator optimal fuel consumption curve to the vehicle demanded power.

In step 22, the engine speed is measured, and the engine power corresponding to the engine-generator optimal fuel consumption curve under the actual engine speed is taken as the maximum output power of the engine-generator.

In step 23, the difference between the required power of the vehicle and the maximum output power of the engine-generator set is used as the target output power of the power battery pack.

In step 24, the maximum output power of the battery pack under the current state is determined according to a known method for calculating the state of charge of the battery.

In step 25, compare the target output power of the power battery pack with the maximum power of the power battery pack in the current state, and take the smaller one as the target output power of the power battery pack. The target output power of the power battery pack is divided by the voltage of the DC bus 12 to obtain the target output current of the battery pack. The DC converter control unit uses a known control method to control the output current of the power battery pack so as to realize the power output of the power battery according to the required power.

In step 26, the sum of the target operating power of the motor I and the motor II is compared with the sum of the maximum operating power of the current engine-generator set and the maximum operating power of the power battery pack, and the smaller one is taken as the target operation of the motor I and the motor II sum of power.

Claims (5)

1. the Poewr control method of a crawler-type hybrid electric vehicle; The bilateral crawler belt of said crawler-type hybrid electric vehicle is respectively by electric motor I and electric motor I I individual drive; Said vehicle has the power output part that is made up of jointly Engine-Generator group and energy storage equipment; Wherein, Engine driven generators and constitute said Engine-Generator group, said control method are realized to said electric motor I and electric motor I I the control of power being provided from said power output part, and said control method has following steps:

A. confirm vehicle needs power, said vehicle needs power is the object run power sum of electric motor I and electric motor I I;

B. confirm Engine-Generator group maximum output power;

C. confirm the energy storage equipment maximum output power;

D. the object run power sum of electric motor I and electric motor I I and present engine-generator set maximum output power and energy storage equipment maximum output power sum are compared, get the smaller as vehicle needs power;

Said vehicle also has power control unit, and this power control unit realizes providing to said electric motor I and electric motor I I from said power output part the control of power:

Said power control unit has memory cell; It stores the best fuel oil consumption curve of said Engine-Generator group; Said step b also comprises the actual speed of measuring driving engine, and said Engine-Generator group maximum output power is in the pairing engine power value of said best the above actual speed of fuel oil consumption curve.

2. the method for claim 1, wherein:

The step that also comprises the rotating speed of target of confirming driving engine, with the value of vehicle needs power on the best fuel oil consumption curve of Engine-Generator group cooresponding engine speed as the rotating speed of target of driving engine.

3. method as claimed in claim 2, wherein:

If vehicle needs power not at the cooresponding power range of best fuel oil consumption curve of Engine-Generator group, is then got on the best fuel oil consumption curve of Engine-Generator group the pairing engine speed of power with vehicle needs power closest point of approach as the engine target rotating speed.

4. the method for claim 1, wherein:

Also comprise the step of the target output of confirming energy storage equipment, the target output of energy storage equipment equals the difference of vehicle needs power and Engine-Generator group maximum output power;

Also be included in energy storage equipment and carry out power when output, if the energy storage equipment maximum output power less than the target output of energy storage equipment, then is reset to the energy storage equipment maximum output power target output of energy storage equipment.

5. the method for claim 1, wherein:

Said energy storage equipment is battery pack, electric capacity or both combinations;

Said vehicle also comprises voltage changer, and said energy storage equipment is connected on electric motor I and the electric motor I I through this voltage changer;

Said voltage changer can with the change of voltage of energy storage equipment be applied on electric motor I and the electric motor I I;

Said voltage changer is a DC voltage converter;

Said vehicle also comprises rectifier, and its AC rectification that is used for the output of Engine-Generator group is a direct current (DC), and above-mentioned direct current (DC) is outputed on electric motor I and the electric motor I I;

The target output of energy storage equipment is divided by the target outgoing current of rectifier output voltage acquisition energy storage equipment, and said DC voltage converter also has control unit, and this control unit is controlled the outgoing current of energy storage equipment.

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