Diesel engine range extender oil shortage judgment and protection control method

Abstract

The invention discloses a diesel engine range extender oil shortage judgment and protection control method which comprises the following steps: step 1, when a range extender is under a power generation working condition, an RCU detects that an engine ECU reports a fuel metering valve control failure fault and a rail pressure deviation fault, and the RCU detects an output power error fault of the range extender; 2, under the starting working condition of the range extender, the RCU detects that an engine ECU reports a fuel oil metering valve control failure fault and a rail pressure deviation fault, and the RCU detects an abnormal shutdown fault of the range extender; and thirdly, oil shortage protection action is conducted, when the first step or the second step is met, the fuel oil shortage state is fed back, shutdown is executed, and the range extender is not allowed to be restarted. According to the invention, self-judgment and self-protection of the range extender system of the diesel engine in the absence of fuel can be realized.

Description

Technical Field

[0001] The present invention relates to the field of new energy power systems, and in particular to a control method for a diesel engine range extender system to perform system self-judgment and self-protection when fuel is lacking. Background Art

[0002] Existing automotive equipment generally detects the fuel tank fuel situation through liquid level sensors or manual timing. However, when the range extender system is on a test bench or with special equipment or when the vehicle is off-line, the fuel level sensor is often not installed, or the range extender is forced to enter the power generation work even if the fuel level sensor is installed and the liquid level is low. In particular, when the vehicle is off-line, in order to save fuel, only a small amount of fuel is often added for factory testing and verification. During the operation of these equipment, when there is a lack of fuel, if it is not detected in time, the engine of the range extender cannot produce torque normally under the power generation condition, resulting in failure to generate electricity normally. At the same time, it will cause the generator to drive the engine to operate in turn. Under such operation, the rail pressure of the engine common rail pipe fluctuates greatly, and the fuel injection is unstable, which further causes incomplete combustion of the mixed gas, and then causes low body temperature, large amount of piston blowby, and incomplete combustion of carbon smoke into the crankcase, which then merges with the oil mist, causing the oil to turn black. If it occurs under the starting condition, the range extender will start and stop frequently, seriously affecting the operation of the system. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a method for judging and protecting a diesel engine range extender from lack of fuel, which can enable the diesel engine range extender system to perform self-judgment and self-protection when lacking fuel.

[0004] To achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0005] A method for judging and protecting a diesel engine range extender from lack of oil, wherein the ECU, RCU and vehicle controller VCU in the diesel engine range extender system are connected via a communication CAN bus. Without installing a liquid level sensor, the method for judging and protecting a diesel engine from lack of oil comprises the following steps:

[0006] Step 1: When the range extender is in power generation condition, the RCU detects that the engine ECU reports a fuel metering valve control failure fault and a rail pressure deviation fault, and the RCU detects an output power error fault of the range extender;

[0007] Step 2: When the range extender is in the starting condition, the RCU detects that the engine ECU reports a fuel metering valve control failure fault and a rail pressure deviation fault, and the RCU detects an abnormal shutdown fault of the range extender;

[0008] Step 3, fuel shortage protection action: When the above step 1 or step 2 is met, the fuel shortage status is fed back and the shutdown is executed, and the range extender is not allowed to be started again.

[0009] Furthermore, in step 1, the fuel metering valve control failure refers to the fuel metering valve being fully opened and the rail pressure value still not improving.

[0010] Furthermore, in step 1, the rail pressure deviation fault refers to that the deviation between the required rail pressure and the actual rail pressure is greater than the required value.

[0011] Furthermore, in step one, the range extender output power error fault refers to the vehicle requiring the range extender to output a specified electric power, but the range extender does not output electric power, which in turn consumes the electric power of the battery.

[0012] Furthermore, in step 2, the abnormal shutdown failure of the range extender refers to when the vehicle start command is established and there is no shutdown command, and the range extender assembly itself does not detect a fault, but the range extender is out of control and enters shutdown mode by itself, and it occurs more than 3 times within the set 60s time.

[0013] Beneficial effects of the present invention:

[0014] During operation, the range extender of the present invention combines its own information in real time to determine whether there is a lack of fuel. Under power generation conditions, when an engine fuel metering valve control failure fault and a rail pressure deviation fault are detected and an output power error fault of the range extender is detected; or under starting conditions, an engine fuel metering valve control failure fault and a rail pressure deviation fault are detected and an abnormal shutdown fault of the range extender is detected, the range extender system enters a lack of fuel protection mode and executes a shutdown, thereby achieving self-judgment and self-protection, and preventing the range extender from working for a long time under a lack of fuel condition, resulting in engine failure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The system architecture diagram of the embodiment of the present invention is as follows;

[0016] Figure 2 : A control logic block diagram of an implementation mode of the present invention. DETAILED DESCRIPTION

[0017] In order to explain the technical content, achieved objectives and effects of the present invention in detail, the following is an explanation in combination with the implementation modes and the accompanying drawings. In the description of the embodiments, it should be understood that the terms indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the drawings, which are only for the convenience of describing the present embodiment and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention.

[0018] like Figure 1This is the system architecture model of the range extender. The ECU, RCU and vehicle controller VCU are connected through the communication CAN bus. When the vehicle determines the need to start power generation, it sends a start command to the RCU; the RCU determines whether there is a lack of fuel based on the information of the internal motor and engine. If there is no lack of fuel, it responds normally to the vehicle's needs and generates electricity; if there is a lack of fuel, it enters the lack of fuel protection mode.

[0019] like Figure 2 This is the core logic block diagram of the range extender system startup preheating control. When the RCU receives the startup and target power generation instructions from the vehicle controller, the RCU immediately responds and starts power generation. The RCU monitors the motor and engine information in real time. If it determines that the system is in a state of lack of fuel, it will promptly feedback the lack of fuel information and execute shutdown to protect the range extender.

[0020] Diesel range extender system oil shortage judgment and protection control method:

[0021] Without installing the liquid level sensor, the judgment of oil shortage is as follows: ① When the range extender is in power generation condition, the RCU detects that the engine ECU reports a fuel metering valve control failure fault and a rail pressure deviation fault, and the RCU detects an output power error fault of the range extender; ② When the range extender is in starting condition, the RCU detects that the engine ECU reports a fuel metering valve control failure fault and a rail pressure deviation fault, and the RCU detects an abnormal shutdown fault of the range extender;

[0022] Judgment of related faults:

[0023] Fuel metering valve control failure means that the fuel metering valve is fully opened and the rail pressure value still does not improve;

[0024] Rail pressure deviation fault means that the deviation between the required rail pressure and the actual rail pressure is greater than the required value;

[0025] The range extender output power error fault means that the vehicle requires the range extender to output a specified amount of power, but the range extender does not output power, which in turn consumes the battery's power;

[0026] The abnormal shutdown fault of the range extender means that when the vehicle start command is established, there is no shutdown command, and the range extender assembly itself does not detect a fault, but the range extender is out of control and automatically enters the shutdown state, and it occurs more than 3 times within the set 60s time;

[0027] Fuel shortage protection action: When the above ① or ② is met, the fuel shortage status is fed back and the engine is shut down, and the range extender is not allowed to be started again.

[0028] During operation, the range extender of the present invention combines its own information in real time to determine whether there is a lack of fuel. Under power generation conditions, when an engine fuel metering valve control failure fault and a rail pressure deviation fault are detected and a range extender output power error fault is detected; or under starting conditions, an engine fuel metering valve control failure fault and a rail pressure deviation fault are detected and an abnormal shutdown fault of the range extender is detected, the range extender system enters a lack of fuel protection mode and executes a shutdown, thereby achieving self-judgment and self-protection.

[0029] Although the present invention has been described in detail above with specific embodiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for judging and protecting a diesel engine range extender from lack of oil, characterized in that: The ECU, RCU and vehicle controller VCU in the diesel engine range extender system are connected via a communication CAN bus. Without installing a liquid level sensor, the oil shortage judgment and protection control method includes the following steps: Step 1: When the range extender is in power generation condition, the RCU detects that the engine ECU reports a fuel metering valve control failure fault and a rail pressure deviation fault, and the RCU detects an output power error fault of the range extender; Step 2: When the range extender is in the starting condition, the RCU detects that the engine ECU reports a fuel metering valve control failure fault and a rail pressure deviation fault, and the RCU detects an abnormal shutdown fault of the range extender; Step 3, fuel shortage protection action: When the above step 1 or step 2 is met, the fuel shortage status is fed back and the shutdown is executed, and the range extender is not allowed to be started again.

2. A diesel engine range extender oil shortage judgment and protection control method according to claim 1, characterized in that: In step 1, the fuel metering valve control failure refers to the fuel metering valve being fully opened and the rail pressure value still not improving.

3. A diesel engine range extender oil shortage judgment and protection control method according to claim 1, characterized in that: In step 1, the rail pressure deviation fault refers to that the deviation between the required rail pressure and the actual rail pressure is greater than the required value.

4. A diesel engine range extender oil shortage judgment and protection control method according to claim 1, characterized in that: In step 1, the range extender output power error fault means that the vehicle requires the range extender to output a specified electric power, but the range extender does not output electric power, which in turn consumes the electric power of the battery.

5. A diesel engine range extender oil shortage judgment and protection control method according to claim 1, characterized in that: In step 2, the abnormal shutdown failure of the range extender refers to when the vehicle start command is established, there is no shutdown command, and the range extender assembly itself does not detect a fault, but the range extender is out of control and enters shutdown mode by itself, and it occurs more than 3 times within the set 60s time.

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