A vehicle-mounted power supply and discharge system control method based on Petri net

Abstract

The present invention discloses a vehicle-mounted power supply and discharge system control method based on Petri net. The vehicle-mounted power supply and discharge system includes a vehicle-mounted generator, a vehicle-mounted energy storage system, a power supply control system, a power distribution control system and a power load; the vehicle-mounted generator includes an original vehicle generator and a backup generator; the vehicle-mounted energy storage system is composed of multiple battery clusters connected in parallel. The vehicle-mounted power supply and discharge system power supply control process based on Petri net established by the present invention can realize system power supply safely and quickly. As long as the power supply and load meet the conditions, the token can be obtained to change and enter the power transmission and distribution system; when the power supply or load fails, the token can also be obtained to change and exit the power transmission and distribution system. And these changes are real-time, which can realize the real-time distribution of electric energy.

Description

Technical Field

[0001] The present invention specifically relates to a vehicle-mounted power supply and discharge system control method based on Petri net, and belongs to the technical field of power supply control. Background Art

[0002] The commonly used vehicle power supply system is to charge the vehicle battery through the engine-driven AC motor attached to the engine by the engine gear belt, and the vehicle outputs a DC low-voltage power supply. However, special vehicles are usually equipped with high-power loads (such as vehicle-mounted laser systems, refrigerators, lasers, radars, etc.). For high-power electrical equipment, a separate diesel generator is usually equipped to provide power, but the diesel generator is large in size and weight, and there are also problems of high noise and air pollution.

[0003] Under the trend of green energy and sustainable development, the new energy storage industry is booming. The fastest growing type of energy storage is electrochemical energy storage, and the mainstream of electrochemical energy storage is lithium-ion batteries. Lithium batteries have the advantages of small size, light weight, high charging and discharging efficiency, safety and stability, long service life, energy saving and environmental protection, etc., which makes the installation volume of vehicle power battery systems grow exponentially.

[0004] It has become a new development trend to equip special vehicles with large-capacity lithium battery energy storage systems. Large-capacity energy storage systems are generally multi-battery clusters in parallel, and special vehicles have a large load, so the control logic of the power supply system between the two is relatively complex. At the same time, considering the limited power of the energy storage system and sudden failures, the on-board generator will still be retained as a backup. In order to achieve the optimal distribution of electric energy, the control of the supply and consumption of the on-board energy storage system, on-board generator and on-board electrical equipment is particularly critical.

[0005] For the convenience of application, large-scale on-board energy storage systems such as mobile power vehicles on the market use the engine to drive the generator to power small on-board loads, and the on-board energy storage system independently supplies power to other large power-consuming equipment. This power supply method will cause low power efficiency of the system. When a battery cluster or a load fails, the system needs to be powered off, affecting the operation of the entire system and failing to meet the power demand in an emergency.

[0006] In addition, it often takes a long time for large-scale energy storage systems to achieve parallel and synchronous operation, including battery system self-inspection, voltage leveling between battery clusters (generally through DCDC boost or buck), and repair of faulty battery clusters, which cannot meet the emergency power needs of the load. Summary of the invention

[0007] In view of the deficiencies of the prior art, the present invention proposes a vehicle-mounted power supply and discharge system control method based on Petri net.

[0008] Terminology Note:

[0009] BCU: Battery Control Unit, battery (cluster) control management unit.

[0010] Power supply control system: The power management system sends different control instructions to the corresponding battery clusters and generators according to the power supply status and distribution system requirements, so that the power supply enters different states (standby, discharge, charge, fault);

[0011] Power distribution control system: Power load management system, which sends different control instructions to the load according to the load status, maximum output power of the power supply side, available energy, etc., so that the load enters the working state, standby state, fault state, etc.; Summary of the invention:

[0013] Petri Net can express the structural characteristics of the system and analyze the dynamics of the system. Its advantage is that it can qualitatively describe and quantitatively analyze the relationship between sequential, concurrent, random and conflicting events in the system, and strictly respond to the execution process of the system. In the Petri Net model, each node has its own independent timing, which can occur as long as the conditions are met. We have established a power supply control process for the on-board power supply and discharge system based on Petri net, which can realize the power supply of the system safely and quickly. As long as the power supply and load meet the conditions, they can obtain the token to change and enter the power transmission and distribution system; when the power supply or load fails, they can also obtain the token to change and exit the power transmission and distribution system. And these changes are real-time, which can realize the real-time distribution of electric energy.

[0014] The technical solution of the present invention is:

[0015] A vehicle-mounted power supply and discharge system control method based on Petri net, the vehicle-mounted power supply and discharge system includes a vehicle-mounted generator, a vehicle-mounted energy storage system, a power supply control system, a power distribution control system and a power load; the vehicle-mounted generator includes an original vehicle generator and a backup generator; the vehicle-mounted energy storage system is composed of multiple battery clusters connected in parallel;

[0016] The steps include:

[0017] (1) Establish a Petri Net model based on the system structure and system workflow of the vehicle power supply and discharge system:

[0018] The places are designed to be different states of battery clusters and power loads, and each place is mutually exclusive; the transition is designed to be the power supply control system and the distribution control system issuing state instructions to the battery clusters and power loads; the token is designed to be the battery clusters and power loads themselves in different states;

[0019] (2) After the power supply control system is powered on at low voltage, the BCU of the battery cluster monitors the status of the battery cluster in real time, determines whether the battery cluster is incorporated into the power transmission and distribution system based on the collected battery cluster status information, and receives instructions from the power supply control system to undergo a transition; when the battery cluster is not faulty, the power supply control system issues an instruction to undergo a transition, entering the "battery cluster can be incorporated" location; when the battery cluster has a fault, the power supply control system issues an instruction to undergo a transition, entering the "fault state cannot be incorporated" location; when the battery cluster fault is restored, the power supply control system issues an instruction to undergo a transition, entering the "battery cluster initial state" location; after self-checking, re-determine whether it can be incorporated;

[0020] (3) For the "integrable battery clusters", the high-power battery clusters respond to the discharge command of the power supply control system first and enter the discharge state; when the on-board energy storage system is fully charged and the on-board generator is working, the power supply control system issues a charging command, and the low-power battery clusters respond to the command and enter the charging state; when the total voltage of the charging battery cluster and the discharging battery cluster reaches the same level, the power supply control system issues a stop charging command and a discharge command, and all battery clusters enter the discharge state; Among them, the sufficient power of the on-board energy storage system means that the output power on the power supply side is greater than the power consumption on the load side;

[0021] (4) During driving, the original vehicle generator works; when the power consumption of the electrical load is less than the power generation of the original vehicle generator, the power supply control system issues a charging command, and the low-power battery cluster enters the charging state. The original vehicle generator supplies power to the electrical load and charges the low-power battery cluster at the same time; when the power consumption of the on-board equipment is greater than the power generation of the on-board generator, the power supply control system issues a discharge command, and the high-power battery cluster enters the discharge state. The battery cluster and the original vehicle generator supply power to the electrical load at the same time;

[0022] (5) When the battery cluster or the on-board generator fails and cannot meet the full power requirements of all power loads, the power supply control system responds to the power demand of the power loads in descending order of urgency based on the power and amount of electricity that can be provided by the power supply side and the power and urgency of the power loads; high-priority power loads are allowed to use power, while low-priority power loads are prohibited from using power; the power loads receive the instructions from the power distribution control system to allow or prohibit power use and enter the corresponding working state or standby state;

[0023] (6) When there is a fault in the power load, it responds to the power distribution system command to enter the fault state and does not send power demand until the fault is restored and then requests power again;

[0024] (7) When the vehicle is parked, the on-board energy storage system is used to supply power to the electrical loads. When the on-board energy storage system is low on power, the power supply control system issues a command to start the backup generator to supply power to the electrical loads. When the on-board energy storage system is sufficiently charged, it supplies power to the electrical loads while charging the low-power battery cluster.

[0025] The beneficial effects of the present invention are:

[0026] 1. In the simplified Petri Net model of the vehicle-mounted power supply and discharge system of the present invention, each node has independent timing, and can be triggered as long as the conditions are met to complete the state transition, and the working state of each component can be adjusted in real time; the working state of each power source (generator, battery cluster) and load in the system can be adjusted in real time, and the generation, transmission, storage and consumption of electric energy between the vehicle-mounted generator, the vehicle-mounted energy storage system and the vehicle-mounted high-power load can be safely controlled; when the state is switched, it can be switched as long as the conditions are met, without powering off and restarting, to ensure the continuous operation of the system; realize the intelligent distribution of electricity between the vehicle-mounted generator, the vehicle-mounted energy storage system and the electrical equipment, and improve the energy utilization efficiency;

[0027] 2. The present invention combines the on-board generator with the on-board energy storage system, and adjusts the charging and discharging state of the on-board energy storage system according to the system working state (battery power, load power, whether the generator is working, etc.); at the same time, the working state of the load is adjusted in real time according to the system working state (power supply capacity on the power supply side, load power demand, etc.), ensuring the safe and reliable operation of the entire system. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a schematic diagram of the structure of the vehicle-mounted power supply and discharge system described in Example 1;

[0029] Figure 2 This is the power supply Petri Net model of the vehicle-mounted power supply and discharge system of the present invention. DETAILED DESCRIPTION

[0030] Some embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0031] Example 1

[0032] like Figure 1 , Figure 2 shown.

[0033] A vehicle-mounted power supply and discharge system control method based on Petri net, the vehicle-mounted power supply and discharge system includes a vehicle-mounted generator, a vehicle-mounted energy storage system, a power supply control system, a power distribution control system and a power load; the vehicle-mounted generator includes an original vehicle generator and a backup generator; the vehicle-mounted energy storage system is composed of multiple battery clusters connected in parallel;

[0034] The power supply control system and distribution system are composed of an electronic control unit and relay switches; the power loads include the vehicle-mounted high-power laser system, starting system, lighting system, and instruments.

[0035] The steps include:

[0036] (1) Establish a Petri Net model based on the system structure and system workflow of the vehicle power supply and discharge system:

[0037] The places are designed to be different states of battery clusters and power loads, and each place is mutually exclusive; the transition is designed to be the power supply control system and the distribution control system issuing state instructions to the battery clusters and power loads; the token is designed to be the battery clusters and power loads themselves in different states;

[0038] A place represents a resource, medium, state, stage, condition, queue, channel, etc. A transition represents an event, action, statement execution, or message sending and receiving, etc. A token represents a dynamic object in a place and can be moved from one place to another.

[0039] According to the real-time status of the on-board generator and battery cluster, as well as the power demand of the power load, determine the battery cluster and power load to be incorporated into the on-board power supply and discharge system, and determine the charge and discharge status of the battery cluster, complete the library change, and realize the intelligent application of the on-board power supply and discharge system;

[0040] (2) After the power supply control system is powered on at low voltage, the BCU of the battery cluster monitors the status of the battery cluster in real time, determines whether the battery cluster is incorporated into the power transmission and distribution system based on the collected battery cluster status information, and receives instructions from the power supply control system to undergo a transition; when the battery cluster is not faulty, the power supply control system issues an instruction to undergo a transition, entering the "battery cluster can be incorporated" location; when the battery cluster has a fault, the power supply control system issues an instruction to undergo a transition, entering the "fault state cannot be incorporated" location; when the battery cluster fault is restored, the power supply control system issues an instruction to undergo a transition, entering the "battery cluster initial state" location; after self-checking, re-determine whether it can be incorporated;

[0041] Battery cluster failures include leakage failure, single cell voltage is too high, single cell voltage is too low, single cell temperature is too high, single cell temperature is too low, single cell pressure difference is too large, single cell temperature difference is too large, and communication failure.

[0042] (3) For the "integrable battery clusters", the high-power battery clusters respond to the discharge command of the power supply control system and enter the discharge state first; when the on-board energy storage system is sufficiently charged and the on-board generator is working, the power supply control system issues a charging command, and the low-power battery clusters respond to the command and enter the charging state; when the total voltage of the charging battery cluster and the discharging battery cluster reaches the same level, the power supply control system issues a stop charging command and a discharge command, and all battery clusters enter the discharge state; among which, the sufficient power of the on-board energy storage system means that the output power on the power supply side is greater than the power consumption on the load side; the definition of a low-power battery cluster is to set a threshold value based on the specific situation of the system. When the power is lower than the defined threshold, it is judged as a low-power battery cluster, otherwise it is a high-power battery cluster.

[0043] (4) During driving, the original vehicle generator works; when the power consumption of the electrical load is less than the power generation of the original vehicle generator, the power supply control system sends a charging command, the low-power battery cluster enters the charging state, and the original vehicle generator charges the low-power battery cluster while supplying power to the electrical load; when the power consumption of the on-board equipment is greater than the power generation of the on-board generator, the power supply control system sends a discharge command, the high-power battery cluster enters the discharge state, and the battery cluster and the original vehicle generator supply power to the electrical load at the same time; the definition of the high-power battery cluster and the low-power battery cluster in step (4) is the same as that in step (3).

[0044] (5) When the battery cluster or the on-board generator fails and cannot meet the full power requirements of all power loads, the power supply control system responds to the power demand of the power loads in descending order of urgency based on the power and amount of electricity that can be provided by the power supply side and the power and urgency of the power loads; high-priority power loads are allowed to use power, while low-priority power loads are prohibited from using power; the power loads receive the instructions from the power distribution control system to allow or prohibit power use and enter the corresponding working state or standby state;

[0045] Regarding the priority of electricity use, specifically, when the vehicle is in driving working state, the whole vehicle electronic control system is powered first, followed by the lighting system and the air conditioning system; when the vehicle is in parking operation state, the special laser system electronic control system is powered first, followed by the radar, laser, cooling system and parking air conditioning;

[0046] (6) When there is a fault in the power load, it responds to the power distribution system command to enter the fault state and does not send power demand until the fault is restored and then requests power again;

[0047] (7) When the vehicle is parked, the on-board energy storage system is used to supply power to the electrical loads. When the on-board energy storage system is low on power, the power supply control system issues a command to start the backup generator to supply power to the electrical loads. When the on-board energy storage system is sufficiently charged, it supplies power to the electrical loads while charging the low-power battery cluster.

Claims

1. A vehicle-mounted power supply and discharge system control method based on Petri net, characterized in that: The vehicle-mounted power supply and discharge system includes a vehicle-mounted generator, a vehicle-mounted energy storage system, a power supply control system, a power distribution control system and a power load; the vehicle-mounted generator includes an original vehicle generator and a backup generator; the vehicle-mounted energy storage system is composed of multiple battery clusters connected in parallel; and the steps are as follows: (1) Establish a Petri Net model based on the system structure and system workflow of the vehicle power supply and discharge system: The places are designed to be different states of battery clusters and power loads, and each place is mutually exclusive; the transition is designed to be the power supply control system and the distribution control system issuing state instructions to the battery clusters and power loads; the token is designed to be the battery clusters and power loads themselves in different states; (2) After the power supply control system is powered on at low voltage, the BCU of the battery cluster monitors the status of the battery cluster in real time, determines whether the battery cluster is incorporated into the power transmission and distribution system based on the collected battery cluster status information, and receives instructions from the power supply control system to undergo a transition; when the battery cluster is not faulty, the power supply control system issues an instruction to undergo a transition, entering the "battery cluster can be incorporated" location; when the battery cluster has a fault, the power supply control system issues an instruction to undergo a transition, entering the "fault state cannot be incorporated" location; when the battery cluster fault is restored, the power supply control system issues an instruction to undergo a transition, entering the "battery cluster initial state" location; after self-checking, it is re-determined whether it can be incorporated; (3) For "integrable battery clusters", high-power battery clusters respond to the discharge command of the power supply control system first and enter the discharge state; when the on-board energy storage system is fully charged and the on-board generator is working, the power supply control system issues a charging command, and the low-power battery cluster responds to the command and changes to the charging state; when the total voltage of the charging battery cluster and the discharging battery cluster reaches the same level, the power supply control system issues a stop charging command and a discharge command, and all battery clusters change to the discharge state; whereby the on-board energy storage system being fully charged means that the output power on the power supply side is greater than the power consumption on the load side; (4) During driving, the original vehicle generator works; when the power consumption of the electrical load is less than the power generation of the original vehicle generator, the power supply control system issues a charging command, and the low-power battery cluster enters the charging state. The original vehicle generator supplies power to the electrical load and charges the low-power battery cluster at the same time; when the power consumption of the on-board equipment is greater than the power generation of the on-board generator, the power supply control system issues a discharge command, and the high-power battery cluster enters the discharge state. The battery cluster and the original vehicle generator supply power to the electrical load at the same time; (5) When the battery cluster or the on-board generator fails and cannot meet the full power requirements of all power loads, the power supply control system responds to the power demand of the power loads in descending order of urgency based on the power and amount of electricity that can be provided by the power supply side and the power and urgency of the power loads; high-priority power loads are allowed to use power, while low-priority power loads are prohibited from using power; the power loads receive the instructions from the power distribution control system to allow or prohibit power use and enter the corresponding working state or standby state; (6) When there is a fault in the power load, it responds to the power distribution system command to enter the fault state and does not send power demand until the fault is restored and then requests power again; (7) When the vehicle is parked, the on-board energy storage system is used to supply power to the electrical loads. When the on-board energy storage system is low on power, the power supply control system issues a command to start the backup generator to supply power to the electrical loads. When the on-board energy storage system is sufficiently charged, it supplies power to the electrical loads while charging the low-power battery cluster.

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