Power supply system

Abstract

The utility model provides a power supply system, which comprises an alternating current conversion module, a vehicle-mounted power supply, a power storage battery, a power supply distribution module and electric equipment, and is characterized in that the power supply distribution module is connected with the electric equipment to output an applicable power supply to supply power to the electric equipment; the alternating current conversion module is connected with an external alternating current power supply to convert into a direct current power supply, the vehicle-mounted power supply is connected with the external alternating current power supply and is connected with the power storage battery to convert the external alternating current power supply into an applicable power supply to charge the power storage battery, and the alternating current conversion module is connected with the vehicle-mounted power supply and the power storage battery in parallel; the alternating current conversion module and the power storage battery are both connected with the power distribution module, and in a working state, one of the alternating current conversion module and the power storage battery is connected with the power distribution module. The power supply system is used for improving the cruising ability and the operation energy efficiency of the power supply system, facilitates rapid transfer of the excavator, and can be suitable for various scenes.

Description

Technical Field

[0001] The utility model relates to the technical field of electric construction machinery, in particular to a power supply system. Background Art

[0002] As a kind of construction machinery widely used in roads, mining and infrastructure construction, excavators have sufficient market demand, which not only promotes the development of excavator manufacturing enterprises, but also prompts the market to continuously emerge excellent excavator products, and the entire excavator industry presents a posture of a hundred schools of thought contending and a hundred flowers blooming.

[0003] At present, there are mainly two power supply systems for excavators. The first is a pure electric system, which uses an on-vehicle power battery as an energy source and is replenished through an external DC charging pile. On the one hand, the pure electric system is limited by factors such as the spatial layout of the excavator and the energy density of the power battery, resulting in a limited capacity of the power battery and insufficient endurance, making it difficult to meet the needs of long-term continuous operation. On the other hand, there is usually a certain distance between the charging pile and the working position of the excavator. For some excavators such as crawler electric excavators with slow walking speeds, it is difficult to charge and replenish energy.

[0004] The second is a trailing power system, which uses an external three-phase power supply as an energy source and generally uses a three-phase asynchronous motor as the main drive source. On the one hand, the speed of the three-phase asynchronous motor cannot be adjusted or the adjustment range is small, which is not conducive to the efficient and energy-saving operation of the excavator. On the other hand, when the excavator is transferred to another site, it is difficult to drag the cable up and down the trailer, and the site limitation is large.

[0005] Therefore, there is an urgent need for a power supply system for excavators to solve the problems of insufficient endurance of the pure electric system, poor operation energy efficiency and difficult transfer of the trailing power system. Summary of the Utility Model

[0006] In order to overcome at least one of the above-mentioned defects of the prior art, the utility model provides a power supply system to improve the endurance and operation energy efficiency of the power supply system, and facilitate the rapid transfer of the excavator, and can be applicable to various scenarios.

[0007] The utility model provides a power supply system, including: an AC conversion module, an on-vehicle power supply, a power battery, a power distribution module and an electrical device. The power distribution module is connected to the electrical device to output a suitable power supply to supply power to the electrical device;

[0008] The AC conversion module accesses an external AC power supply to convert it into a DC power supply. The on-vehicle power supply accesses the external AC power supply and is connected to the power battery to convert the external AC power supply into a suitable power supply to charge the power battery. The AC conversion module is arranged in parallel with the on-vehicle power supply and the power battery;

[0009] The AC conversion module and the power battery are both connected to the power distribution module. In the working state, either the AC conversion module or the power battery is in an on state with the power distribution module.

[0010] As an alternative implementation, in the present utility model, the vehicle-mounted power supply includes a vehicle-mounted charger and a DC converter connected in series. The vehicle-mounted charger accesses an external AC power supply to convert it into a DC power supply, and the DC converter is connected to the power battery to convert the DC power supply into a suitable power supply to charge the power battery.

[0011] As an alternative implementation, in the present utility model, both the AC conversion module and the power battery are connected to the power distribution module through a DC converter.

[0012] As an alternative implementation, in the present utility model, relays are provided on the circuits between the AC conversion module and the power battery and the power distribution module. In the working state, the on-off states of the two relays are opposite.

[0013] As an alternative implementation, in the present utility model, the vehicle-mounted power supply and the AC conversion module are connected in parallel to an AC distribution box, and the AC distribution box accesses an external AC power supply.

[0014] As an alternative implementation, in the present utility model, a leakage protection device is provided between the vehicle-mounted power supply and the AC conversion module and the external AC power supply.

[0015] As an alternative implementation, in the present utility model, the power distribution module and the vehicle-mounted power supply are connected to the whole machine controller through a communication network. The whole machine controller is connected to the AC conversion module through an AC module controller via the communication network, and is connected to the power battery through a battery management system.

[0016] As an alternative implementation, in the present utility model, the whole machine controller is connected to an instrument through a communication network, and the instrument is used to set the on-off states of the AC conversion module and the power battery and the power distribution module in the working state.

[0017] As an alternative implementation, in the present utility model, the electrical equipment includes a permanent magnet synchronous motor.

[0018] The beneficial effects of the power supply system provided by the present utility model are as follows:

[0019] By setting the AC conversion module in parallel with the vehicle-mounted power supply and the power battery, two power supply modes can be provided for the excavator. The first is power supply by the power battery, and the second is that the AC conversion module accesses an external AC power supply to supply power in a drag power mode. Thus, these two power supply modes can be flexibly switched during the power consumption process of the excavator, thereby improving the endurance and operation energy efficiency of the power supply system, and facilitating the rapid transfer of the excavator, making it applicable to a variety of scenarios.

[0020] Moreover, as long as there is an external AC power supply, the power battery can be charged at any time to ensure that the power battery has sufficient power, thereby improving the endurance when using the power battery for power supply. At the same time, the power battery does not need to be selected with a large capacity, which can greatly reduce costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the power supply system of the present utility model;

[0022] Figure 2 It is a schematic diagram of the principle of the power supply system of the present utility model;

[0023] Figure 3 It is a schematic diagram of the communication network of the power supply system of the present utility model;

[0024] Figure 4 It is a flowchart of the power mode switching of the power supply system of the present utility model;

[0025] Figure 5 It is a flowchart of the pure electric mode of the power supply system of the present utility model;

[0026] Figure 6 It is a flowchart of the automatic mode of the power supply system of the present utility model.

[0027] Among them, the meanings of the reference numerals are as follows:

[0028] 1. AC conversion module; 2. Vehicle-mounted charger; 3. Power battery; 4. Power distribution module; 5. AC distribution box; 6. Whole machine controller; 7. AC module controller; 8. Battery management system; 9. Instrument; 10. Power system; 11. Electric drive accessories. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] For better understanding and implementation, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the drawings in the embodiments of the present utility model.

[0030] In the description of the present invention, it should be noted that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc. indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present invention.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0032] See also Figure 1 The utility model provides a power supply system, including: an AC conversion module 1, an on-board power supply, a power storage battery 3, a power distribution module 4 and an electric device, wherein the power distribution module 4 is connected to the electric device to output a suitable power supply to power the electric device. The AC conversion module 1 is connected to an external AC power supply to convert it into a DC power supply, the on-board power supply is connected to an external AC power supply and connected to the power storage battery 3 to convert the external AC power supply into a suitable power supply to charge the power storage battery 3, and the AC conversion module 1 is arranged in parallel with the on-board power supply and the power storage battery 3. The AC conversion module 1 and the power storage battery 3 are both connected to the power distribution module 4, and in the working state, one of the AC conversion module 1 and the power storage battery 3 is connected to the power distribution module 4.

[0033] Among them, the AC conversion module 1 is an AC / DC converter, which converts the external AC power supply into a DC power supply after rectification. The on-board power supply is used to convert the external AC power supply into an applicable DC power supply to charge the power battery 3. The power battery 3 and the AC conversion module 1 are both used to transmit the power supply to the power distribution module 4. The power distribution module 4 can be an all-in-one controller to distribute the applicable power to the corresponding power-consuming equipment. The power-consuming equipment includes a power system 10 and electric drive accessories 11. The power system 10 includes a permanent magnet synchronous motor, an inverter, etc. The electric drive accessories 11 include a DC converter (DC-DC), an air-conditioning compressor, etc. There are many types of excavator power equipment, which are not listed here one by one.

[0034] Thus, the power supply system can provide two power supply modes. In the first mode, the AC conversion module 1 is in a disconnected state from the power distribution module 4, and the power battery 3 is in a connected state with the power distribution module 4. The power battery 3 serves as the power source to supply power to the electrical equipment through the power distribution module 4. This mode is generally used in scenarios where there is no external AC power supply, or when the excavator is being relocated, to avoid the difficulty of dragging cables on and off the trailer, thus improving the convenience of excavator relocation.

[0035] In the second mode, the power battery 3 is in a disconnected state from the power distribution module 4, and the AC conversion module 1 is in a connected state with the power distribution module 4. The external AC power supply serves as the power source. After the AC conversion module 1 converts the AC power into DC power, the power distribution module 4 supplies power to the electrical equipment. This mode is generally used in scenarios where there is an external AC power supply and the excavator needs to work continuously for a long time, to improve the endurance of the power supply system. Moreover, in this mode, if the power battery 3 has insufficient power, the external AC power supply can be used to charge the power battery 3 through the on-vehicle power supply. The charging process of the power battery 3 and the process of the external AC power supply supplying power to the electrical equipment through the AC conversion module 1 and the power distribution module 4 do not interfere with each other, and neither the charging efficiency of the power battery 3 nor the power supply efficiency for the electrical equipment is affected, and both can be carried out efficiently. Thus, as long as there is an external AC power supply, the power battery 3 can be charged at any time to ensure that the power battery 3 has sufficient power, thereby improving the endurance when using the power battery 3 for power supply. At the same time, the power battery 3 does not need to be selected with a large capacity, which can greatly reduce costs.

[0036] It can be seen from this that compared with the system that solely uses the power battery 3 as the power source, this power supply system greatly improves the endurance. Compared with the trailing cable system, it improves the convenience of excavator relocation. Thus, this power supply system can meet various application scenarios of the excavator, and users can flexibly select according to actual needs, with high reliability.

[0037] In addition, the electrical equipment uses a permanent magnet synchronous motor as the drive motor, which can adjust different speeds according to different working conditions, enabling the speed to be accurately matched with the specific working conditions, and having the characteristics of energy saving and high efficiency.

[0038] Based on this, combined with Figure 1-2 a detailed description of the power supply system of the present utility model will be given.

[0039] The on-vehicle power supply includes an on-vehicle charger (OBC) 2 and a DC converter connected in series. The on-vehicle charger 2 accesses the external AC power supply to convert it into DC power, and the DC converter is connected to the power battery 3 to convert the DC power into a suitable power source to charge the power battery 3.

[0040] The external AC power supply, in-vehicle charger 2, DC converter, and power battery 3 are connected in series in sequence. The external AC power supply is converted into DC power by the in-vehicle charger 2, and then the voltage is reduced by the DC converter to be suitable for charging the power battery 3. In this way, efficient and safe charging of the power battery 3 can be achieved.

[0041] Both the AC conversion module 1 and the power battery 2 are connected to the power distribution module 4 through DC converters. It should be noted that different types of DC converters can be selected for the AC conversion module 1 and the power battery 2, as long as it can ensure that the converted voltage power is suitable for being distributed to electrical devices for power supply through the power distribution module 4.

[0042] Relays are provided on the circuits between the AC conversion module 1 and the power battery 3 and the power distribution module 4. In the working state, the on-off states of the two relays are opposite. Specifically, a relay K2 is provided on the circuit between the AC conversion module 1 and the power distribution module 4, and a relay K1 is provided on the circuit between the power battery (Pack) 3 and the power distribution module 4. When the power battery is required to be the power source, the relay K1 is turned on and the relay K2 is turned off. Conversely, the relay K1 is turned off and the relay K2 is turned on. In this way, the switching of the power source mode can be easily and accurately completed through the opposite on-off states of the relay K1 and the relay K2 to achieve flexible selection of the power source.

[0043] On this basis, multiple electrical devices are connected in parallel to the power distribution module 4, and the on-off of each single circuit is controlled by a relay to ensure that the usage states of the electrical devices do not interfere with each other.

[0044] In addition, the vehicle power supply and the AC conversion module 1 are connected in parallel to the AC distribution box 5, and the AC distribution box 5 is connected to the external AC power supply. The setting of the AC distribution box 5 facilitates the vehicle power supply and the AC conversion module 1 to be connected to the external AC power supply at the same time, ensuring that there is no interference between the two branch lines of charging the power battery 3 and supplying power to electrical devices by the external AC power supply through the AC conversion module 1 and the power distribution module 4, and both are efficient.

[0045] Moreover, a leakage protection device (RCD) is provided between the vehicle power supply and the AC conversion module 1 and the external AC power supply to improve the electrical safety.

[0046] Refer to Figure 3 , the power distribution module 4 and the vehicle power supply are connected to the whole machine controller 6 through a communication network. The whole machine controller 6 is connected to the AC conversion module 1 through the AC module controller 7 via the communication network, and is connected to the power battery 3 through the battery management system 8.

[0047] The whole machine controller 6, as the main controller of the excavator, can send instructions to the power distribution module 4 according to the requirements of the electrical equipment to allocate appropriate voltage power supplies, and can send instructions to the vehicle-mounted power supply, i.e., the on-vehicle charger 2, according to the charging requirements of the power battery 3 to charge the power battery 3. At the same time, the whole machine controller 6 can control the voltage power supply after rectification of the AC conversion module 1 through the AC module controller 7 according to the power consumption requirements of the electrical equipment. Moreover, the whole machine controller 6 can also monitor the status of the power battery 3 through the battery management system 8 and issue corresponding instructions in a timely manner. All in all, the setting of the communication network enables the power supply system of the excavator to achieve intelligence and automation, capable of efficiently obtaining the status and requirements of each component, and issuing instructions in a timely manner through the whole machine controller 6 to complete corresponding operations.

[0048] The whole machine controller 6 is connected to an instrument 9 through a communication network. The instrument 9 is used to set the on-off status of the AC conversion module 1, the power battery 3, and the power distribution module 4 in the working state.

[0049] The instrument 9 can include two modes for selection, namely the automatic mode and the pure electric mode. The user can select the power supply mode through the instrument 9, and the instrument 9 transmits the signal to the whole machine controller 6, and the whole machine controller 6 issues instructions to perform the power supply operation in the corresponding mode.

[0050] Among them, in the automatic mode, the whole machine controller 6 obtains a signal to judge whether there is an external AC power supply connected. If so, it uses the AC conversion module 1 to connect to the external AC power supply, and then supplies power to the electrical equipment through the power distribution module 4. During this process, the whole machine controller 6 can obtain the power level of the power battery 3 to decide whether to issue an instruction to charge the power battery 3 using the external AC power supply through the vehicle-mounted power supply. If there is no external AC power supply connected, the whole machine controller 6 issues an instruction to make the power battery 3 supply power to the electrical equipment through the power distribution module 4.

[0051] In the pure electric mode, the whole machine controller 6 issues an instruction to make the power battery 3 supply power to the electrical equipment through the power distribution module 4. During this process, if there is an external AC power supply connected, the external AC power supply can be used to charge the power battery 3 through the vehicle-mounted power supply to improve the endurance of the power battery 3, and the power battery 3 does not need to have a large capacity, greatly reducing costs.

[0052] It should be noted that referring to Figure 4 , the default power supply mode of the excavator is the automatic mode. If it is necessary to switch to the pure electric mode, the switching operation needs to be performed before the excavator is started to avoid affecting the normal use of the excavator.

[0053] Based on this, the control principle of the power supply system of the present invention will be described in detail below.

[0054] S1. The default power supply mode of the excavator is the automatic mode. In the automatic mode, before the excavator starts, the whole machine controller 6 obtains the current AC input voltage to determine whether there is an external AC power supply input.

[0055] S11. If there is an external AC power supply input, the relay K2 is turned on and the relay K1 is turned off. The AC conversion module 1 converts the connected external AC power supply into a DC power supply after rectification, and performs voltage conversion through the DC converter to transmit it to the power distribution module 4. Then, the power distribution module 4 distributes appropriate voltage power supplies to the electrical equipment. This is generally used in scenarios where there is an external AC power supply and the excavator needs to work continuously for a long time to improve the endurance of the power supply system.

[0056] During this process, the whole machine controller 6 obtains the current power (SOC) of the power battery 3. If the SOC is lower than the minimum power SOC1 of the power battery 3 set by the system, such as 50% of the maximum capacity, the whole machine controller 6 issues an instruction to make the on-vehicle charger 2 connect to the external AC power supply to be converted into a DC power supply, and performs voltage conversion through the DC converter to charge the power battery 3 until the SOC of the power battery 3 is not lower than the maximum power SOC2 of the power battery 3 set by the system, such as 95% of the maximum capacity.

[0057] In this case, the charging process of the power battery 3 and the process of supplying power to the electrical equipment by the external AC power supply through the AC conversion module 1 and the power distribution module 4 do not interfere with each other, and have no impact on the charging efficiency of the power battery 3 and the power supply efficiency for the electrical equipment. Both can be carried out efficiently. In this way, as long as there is an external AC power supply, the power battery 3 can be charged at any time to ensure that the power battery 3 has sufficient power, thereby improving the endurance when using the power battery 3 for power supply. At the same time, the power battery 3 does not need to select a large capacity, which can greatly reduce the cost.

[0058] S12. If there is no external AC power supply input, the relay K1 is turned on and the relay K2 is turned off. The power of the power battery 3 is subjected to voltage conversion through the DC converter to be transmitted to the power distribution module 4. Then, the power distribution module 4 distributes appropriate voltage power supplies to the electrical equipment. This is generally used in the case of the excavator moving the site to avoid the difficulty of dragging the cable up and down the trailer and improve the convenience of the excavator moving the site.

[0059] S2. Before the excavator starts, the user uses the instrument 9 to switch the power supply mode to the pure electric mode. The whole machine controller 6 controls the relay K1 to be turned on and the relay K2 to be turned off. The power of the power battery 3 is subjected to voltage conversion through the DC converter to be transmitted to the power distribution module 4. Then, the power distribution module 4 distributes appropriate voltage power supplies to the electrical equipment.

[0060] During this process, the whole machine controller 6 obtains the current AC input voltage to determine whether there is an external AC power input. If there is, the whole machine controller 6 issues an instruction to make the on-vehicle charger 2 access the external AC power to convert it into DC power, and the voltage is converted by the DC converter to charge the power battery 3. At this time, while the power battery 3 is supplying power to the electrical equipment, it is also charging itself with the external AC power to ensure that the power of the power battery 3 slowly decreases or does not decrease, so as to improve the endurance. This is generally applicable to the situation where the AC conversion module 1 fails and the excavator needs to operate continuously for a long time. Since the power battery 3 can be charged during the power supply process, the power battery 3 does not need to use a large capacity, which can reduce costs.

[0061] If not, the whole machine controller 6 only controls the power battery 3 to supply power to the electrical equipment as a power source. This is generally applicable to the situation of emergency use or site transfer of the excavator, improving the convenience of using the excavator.

[0062] The technical means disclosed in the solution of the present utility model are not limited to the technical means disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that for those of ordinary skill in the art in this technical field, without departing from the principle of the present utility model, several improvements and retouches can be made, and these improvements and retouches are also regarded as the protection scope of the present utility model.

Claims

1. A power supply system, characterized in that, Comprising: An AC conversion module, a vehicle-mounted power supply, a power battery, a power distribution module, and an electrical device. The power distribution module is connected to the electrical device to output a suitable power supply to supply power to the electrical device; The AC conversion module accesses an external AC power supply to convert it into a DC power supply. The vehicle-mounted power supply accesses the external AC power supply and is connected to the power battery to convert the external AC power supply into a suitable power supply to charge the power battery. The AC conversion module is arranged in parallel with the vehicle-mounted power supply and the power battery; Both the AC conversion module and the power battery are connected to the power distribution module. In the working state, one of the AC conversion module and the power battery is in an on state with the power distribution module.

2. The power supply system according to claim 1, wherein: The vehicle-mounted power supply includes a vehicle-mounted charger and a DC converter connected in series. The vehicle-mounted charger accesses the external AC power supply to convert it into a DC power supply. The DC converter is connected to the power battery to convert the DC power supply into a suitable power supply to charge the power battery.

3. The power supply system according to claim 1 or 2, characterized in that: Both the AC conversion module and the power battery are connected to the power distribution module through a DC converter.

4. The power supply system according to claim 1 or 2, characterized in that: Relays are provided on the circuits between the AC conversion module and the power battery and the power distribution module. In the working state, the on-off states of the two relays are opposite.

5. The power supply system according to claim 1, wherein: The vehicle-mounted power supply and the AC conversion module are connected in parallel to an AC distribution box, and the AC distribution box accesses the external AC power supply.

6. The power supply system according to claim 1 or 5, characterized in that: A leakage protection device is provided between the vehicle-mounted power supply and the AC conversion module and the external AC power supply.

7. The power supply system according to claim 1, characterized in that: The power distribution module and the vehicle-mounted power supply are connected to the whole machine controller through a communication network. The whole machine controller is connected to the AC conversion module through an AC module controller via the communication network, and is connected to the power battery through a battery management system.

8. The power supply system according to claim 7, wherein: The whole machine controller is connected to an instrument through a communication network. The instrument is used to set the on-off states of the AC conversion module and the power battery and the power distribution module in the working state.

9. The power supply system according to claim 1, wherein: The electrical device includes a permanent magnet synchronous motor.

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