A dual-source trackless trolleybus charging system and its control method

Abstract

The present invention relates to a charging system for a dual-source trolleybus and a control method thereof, belonging to the technical field of dual-source trolleybus charging. The method includes: during the static charging process, the whole vehicle makes a power request according to the battery-allowed charging power, and the actual response power of the isolated DC / DC converter is collected in real time; when the actual response power exceeds the battery-allowed charging power, the error value between the actual response power and the battery-allowed charging power is calculated; the battery-allowed charging power is corrected according to the error value, and the corrected battery-allowed charging power is the battery-allowed charging power before correction minus the error value; at the next moment, the battery-allowed charging power is updated to the corrected battery-allowed charging power, and the whole vehicle makes a power request according to the updated battery-allowed charging power; until the actual response power ≤ the battery-allowed charging power, normal charging is carried out. The present invention avoids the situation of overcharging beyond the limit and improves the reliability of charging.

Description

Technical Field

[0001] The present invention relates to a charging system for a dual-source trolleybus and a control method thereof, belonging to the technical field of dual-source trolleybus charging. Background Art

[0002] Currently, most pure electric buses are charged through charging piles in the depot, and the cruising range and the queue for charging piles are still issues that users are concerned about. The dual-source trolleybus can use the overhead line network to replenish the power battery without occupying new public resources, which alleviates the problem of difficult charging of electric vehicles to a certain extent.

[0003] The dual-source trolleybus has two modes: pure electric mode and grid-connected mode. In the pure electric mode, the vehicle is driven only by consuming the power of the power battery. In the grid-connected mode, the vehicle is connected to the overhead line network through a pantograph, and the isolated DC / DC converter can charge the battery or provide energy for the vehicle operation. When the whole vehicle is running in the grid-connected mode, the power replenished to the battery by the isolated DC / DC should meet the power consumption in the whole pure electric mode to achieve the balance of the battery power. Therefore, during the operation of the vehicle, the battery is always in a state of continuous charging and discharging but not fully charged. After the vehicle is parked, the battery can still be charged using the night valley grid connection to reach the set threshold to a certain extent.

[0004] When charging with the night valley grid connection after the vehicle is parked, the whole vehicle requests the isolated DC / DC converter to respond with the corresponding current according to the allowable charging current of the battery. However, for vehicles without supervision at night, during the charging process, due to factors such as large fluctuations in the overhead line network voltage, low response accuracy of the isolated DC / DC converter, or inconsistent communication cycles, the phenomenon that the response current of the isolated DC / DC converter exceeds the allowable charging current of the battery often occurs. If the response current of the isolated DC / DC converter exceeds the set threshold of the allowable charging current of the battery and lasts for a long time, it is considered that the charging is over-limit, which will affect the battery life and even cause dangerous situations such as fire. Therefore, for this situation of over-limit charging, the existing technologies generally adopt two methods: 1. directly reduce the allowable charging current of the battery to half of the original, thereby reducing the requested current; 2. stop charging.

[0005] However, based on the existing processing methods, there will be situations of non-charging or long-term power-limited charging. For vehicles without supervision at night, it often results in the battery power not reaching the driving requirement the next day, and the charging reliability is poor. Summary of the Invention

[0006] The purpose of this application is to provide a charging system for a dual-source trolleybus and a control method thereof, so as to solve the problem of poor reliability of night charging of existing dual-source trolleybuses.

[0007] To achieve the above object, the present application proposes a technical solution for a control method of a dual-source trackless trolley charging system, including the following steps:

[0008] 1) During the static charging process, the whole vehicle makes a power request according to the battery allowable charging power, and the actual response power of the isolated DC / DC converter is collected in real time;

[0009] 2) When the actual response power of the isolated DC / DC converter exceeds the battery allowable charging power, calculate the error value between the actual response power of the isolated DC / DC converter and the battery allowable charging power;

[0010] 3) Correct the battery allowable charging power according to the error value, and the corrected battery allowable charging power is the battery allowable charging power before correction minus the error value;

[0011] 4) Update the battery allowable charging power to the corrected battery allowable charging power at the next moment, and the whole vehicle makes a power request according to the updated battery allowable charging power;

[0012] 5) Judge the magnitude relationship between the actual response power of the isolated DC / DC converter and the battery allowable charging power:

[0013] If the actual response power of the isolated DC / DC converter ≤ the battery allowable charging power, normal charging is carried out; if the actual response power of the isolated DC / DC converter > the battery allowable charging power, repeat steps 2) to 4) until the actual response power of the isolated DC / DC converter ≤ the battery allowable charging power, and then normal charging is carried out.

[0014] In addition, the present application also proposes a technical solution for a dual-source trackless trolley charging system, including an isolated DC / DC converter, a pantograph, and a controller. The controller is connected to the isolated DC / DC converter and the pantograph. The input end of the pantograph is used to connect to the wire network, the output end of the pantograph is connected to the input end of the isolated DC / DC converter, and the output end of the isolated DC / DC converter is used to connect to the battery. The controller is characterized in that it includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the above control method of the dual-source trackless trolley charging system.

[0015] The beneficial effects of the technical solution of the dual-source trolleybus charging system and its control method of the present invention are as follows: When the real-time response power exceeds the battery's allowable charging power, the present invention timely adjusts the battery's allowable charging power according to the exceeded error value, and then timely adjusts the requested power. By means of cyclic adjustment, it is ensured that the actual response power is lower than the battery's allowable charging power before normal charging, avoiding the situation of over-limit charging, and further avoiding the phenomenon of significantly reducing the charging current or not charging due to over-limit charging, thus improving the reliability of charging.

[0016] Further, in the above-mentioned dual-source trolleybus charging system and its control method, in order to ensure the charging efficiency, the error value is calculated in the way of a rolling time window. The error value is the average value of the differences between the actual response power of the isolated DC / DC converter and the battery's allowable charging power at each moment within the rolling time window. For a certain moment, if the actual response power of the isolated DC / DC converter ≤ the battery's allowable charging power, the difference between the actual response power of the isolated DC / DC converter and the battery's allowable charging power is 0.

[0017] Further, in the above-mentioned dual-source trolleybus charging system and its control method, in order to ensure the safety of the charging system, if a fault occurs during the static charging process, the charging is stopped.

[0018] Further, in the above-mentioned dual-source trolleybus charging system and its control method, the faults include bilateral insulation resistance faults, over-temperature faults, and single-cell over-voltage faults.

[0019] Further, in the above-mentioned dual-source trolleybus charging system and its control method, before static charging, it also includes the step of judging the charging time: when the current moment enters the preset time period, the static charging is started.

[0020] Further, in the above-mentioned dual-source trolleybus charging system and its control method, in order to avoid the peak electricity consumption period, the preset time period is the off-peak period of night electricity consumption.

[0021] Further, in the above-mentioned dual-source trolleybus charging system, in order to ensure the safety of the current collector pole and the charging system, after normal charging ends, the controller controls the current collector pole to automatically retract into the top cabin.

[0022] Further, in the above-mentioned dual-source trolleybus charging system, in order to ensure the safety of the current collector pole and the charging system, if a fault occurs during the static charging process, after the charging is stopped, the controller controls the current collector pole to automatically retract into the top cabin. Description of the Drawings

[0023] Figure 1 It is the flowchart of the control method of the dual-source trolleybus charging system of the present invention. Detailed Embodiment

[0024] Embodiment of a dual-source trackless trolley charging system:

[0025] The main concept of the present invention lies in the problem of poor reliability of the existing control method. The present invention monitors the actual response power of the isolated DC / DC converter in real time. When the actual response power of the isolated DC / DC converter exceeds the battery allowable charging power, the exceeded error value is calculated, and then the battery allowable charging power is corrected according to the error value. When the vehicle requests power at the next moment, the charging power is requested according to the corrected battery allowable charging power. And when the actual response power is greater than the battery allowable charging power, the battery allowable charging power is cyclically corrected until the actual response power is less than or equal to the battery allowable charging power, and normal charging is carried out. The control method of the present invention avoids the occurrence of overcharging phenomenon and improves the reliability of charging.

[0026] The dual-source trackless trolley charging system includes an isolated DC / DC converter, a pantograph, and a controller. The controller is connected to the isolated DC / DC converter and the pantograph. The input end of the pantograph is used to connect to the catenary network. The output end of the pantograph is connected to the input end of the isolated DC / DC converter. The output end of the isolated DC / DC converter is used to connect to the battery. The controller includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the control method of the dual-source trackless trolley charging system is implemented.

[0027] The control method of the dual-source trackless trolley charging system is as Figure 1 shown and includes the following steps:

[0028] 1) After the vehicle is parked and connected to the network at the station, the driver can leave work. Judge the charging time of the vehicle to determine whether it enters a preset time period. If the current time enters the preset time period, start static charging and enter step 2). If the current time does not enter the preset time period, wait.

[0029] In this step, the preset time period is the night power valley time period. As other embodiments, the preset time period can be modified as needed, or directly charged after connecting to the network without setting a preset time period. The present invention does not limit this.

[0030] 2) During the static charging process, the whole vehicle requests power according to the battery allowable charging power (that is, the vehicle request power = the battery allowable charging power), and the actual response power of the isolated DC / DC converter is collected in real time, and the actual response power of the isolated DC / DC converter is recorded in a rolling time window manner.

[0031] 3) When the actual response power of the isolated DC / DC converter exceeds the allowable charging power of the battery, calculate the difference between the actual response power of the isolated DC / DC converter and the allowable charging power of the battery at each moment within the corresponding rolling time window at this moment, and take the average value of all differences as the error value between the actual response power of the isolated DC / DC converter and the allowable charging power of the battery.

[0032] In this step, for a certain moment within the rolling time window, if the actual response power of the isolated DC / DC converter ≤ the allowable charging power of the battery, define the difference between the actual response power of the isolated DC / DC converter and the allowable charging power of the battery as 0. Only when the actual response power of the isolated DC / DC converter > the allowable charging power of the battery, the calculated difference is positive and is a valid difference.

[0033] 4) Correct the allowable charging power of the battery according to the error value calculated in step 3). The corrected allowable charging power of the battery is the allowable charging power before correction minus the error value, that is, reduce the allowable charging power of the battery, and then reduce the vehicle request power.

[0034] 5) Update the allowable charging power of the battery to the corrected allowable charging power at the next moment, and the vehicle requests power according to the updated allowable charging power of the battery.

[0035] For example: There are ten moments of actual response power W1, W2, W3, W4, W5, W6, W7, W8, W9, W10 within the rolling time window, and the allowable charging power of the battery is W, where W1, W2, W3 < W, W4, W5, W6 = W, W7, W8, W9, W10 > W, then the error value m is

[0036] m = ((W1 - W) + (W2 - W) + (W3 - W) + (W4 - W) + (W5 - W) + (W6 - W) + (W7 - W) + (W8 - W) + (W9 - W) + (W10 - W)) / 10 = (0 + 0 + 0 + 0 + 0 + 0 + (W7 - W) + (W8 - W) + (W9 - W) + (W10 - W)) / 10 = ((W7 - W) + (W8 - W) + (W9 - W) + (W10 - W)) / 10;

[0037] Furthermore, the updated allowable charging power of the battery W = W - m is obtained.

[0038] 6) Judge the magnitude relationship between the actual response power of the isolated DC / DC converter and the allowable charging power of the battery:

[0039] If the actual response power of the isolated DC / DC converter ≤ the allowable charging power of the battery, charge normally;

[0040] If the actual response power of the isolated DC / DC converter > the battery allowable charging power, repeat steps 3) to 5) until the actual response power of the isolated DC / DC converter ≤ the battery allowable charging power, and then perform normal charging.

[0041] 7) After normal charging ends, the controller controls the current collector pole to automatically retract into the top cabin. If a fault occurs during the static charging process, the vehicle no longer requests the output power of the isolated DC / DC converter, stops charging, and after stopping charging, the controller controls the current collector pole to automatically retract into the top cabin.

[0042] The faults here include internal communication faults (i.e., the communication between the controller and the isolated DC / DC converter is interrupted), over-temperature faults (i.e., the battery temperature exceeds the temperature threshold), single-cell overvoltage faults (the voltage of a single battery is higher than the voltage threshold), bilateral insulation resistance faults (i.e., the value of the bilateral insulation resistance is less than the resistance threshold), and other serious faults.

[0043] In the above embodiments, in order to ensure the charging efficiency, the error value is calculated in a rolling time window manner. As other implementation manners, the difference between the actual response power of the isolated DC / DC converter exceeding the battery allowable charging power at a certain moment can also be directly used as the error value to adjust the battery allowable charging power. The present invention does not limit this.

[0044] In the above embodiments, in order to ensure the safety of the current collector pole and the charging system, the connection between the current collector pole and the wire network is disconnected in time after being fully charged or stopping charging due to a fault, and the current collector pole is retracted. As other implementation manners, the current collector pole can also be retracted manually, and a cut-off measure is set inside the system. The present invention does not limit this.

[0045] When the real-time response power of the present invention exceeds the battery allowable charging power, the battery allowable charging power is adjusted in time according to the exceeded error value, and then the requested power is adjusted in time, so as to ensure that the actual response power is lower than the battery allowable charging power through a cyclic adjustment method and perform normal charging, avoiding the situation of charging exceeding the limit, and further avoiding the phenomenon of charging with a large current reduction or not charging due to charging exceeding the limit, thereby improving the charging reliability.

[0046] Embodiment of the control method for a dual-source trolleybus charging system:

[0047] The specific implementation process of the control method for the dual-source trolleybus charging system has been introduced in the above embodiments of the dual-source trolleybus charging system, and will not be elaborated here.

Claims

1. A control method for a dual-source trolleybus charging system, characterized in that, it includes the following steps: 1) During the static charging process, the whole vehicle makes a power request according to the battery's allowable charging power and real-time collects the actual response power of the isolated DC / DC converter; 2) When the actual response power of the isolated DC / DC converter exceeds the battery's allowable charging power, calculate the error value between the actual response power of the isolated DC / DC converter and the battery's allowable charging power; 3) Correct the battery's allowable charging power according to the error value, and the corrected battery's allowable charging power is the battery's allowable charging power before correction minus the error value; 4) At the next moment, update the battery's allowable charging power to the corrected battery's allowable charging power, and the whole vehicle makes a power request according to the updated battery's allowable charging power; 5) Judge the magnitude relationship between the actual response power of the isolated DC / DC converter and the battery's allowable charging power: If the actual response power of the isolated DC / DC converter ≤ the battery's allowable charging power, normal charging is carried out; If the actual response power of the isolated DC / DC converter > the battery's allowable charging power, repeat steps 2) to 4) until the actual response power of the isolated DC / DC converter ≤ the battery's allowable charging power, and then carry out normal charging.

2. The control method for a dual-source trolleybus charging system according to claim 1, characterized in that, calculate the error value in the way of a rolling time window, and the error value is the average value of the differences between the actual response power of the isolated DC / DC converter and the battery's allowable charging power at each moment within the rolling time window. For a certain moment, if the actual response power of the isolated DC / DC converter ≤ the battery's allowable charging power, the difference between the actual response power of the isolated DC / DC converter and the battery's allowable charging power is 0.

3. The control method for a dual-source trolleybus charging system according to claim 1, characterized in that, if a fault occurs during the static charging process, stop charging.

4. The control method for a dual-source trolleybus charging system according to claim 3, characterized in that, the faults include bilateral insulation resistance faults, over-temperature faults, and single-cell over-voltage faults.

5. The control method for a dual-source trolleybus charging system according to claim 1, characterized in that, before static charging, it further includes a step of judging the charging time: when the current moment enters the preset time period, start static charging.

6. The control method for a dual-source trolleybus charging system according to claim 5, characterized in that, the preset time period is the off-peak time period of night electricity consumption.

7. A dual-source trolleybus charging system, including an isolated DC / DC converter, a pantograph, and a controller. The controller is connected to the isolated DC / DC converter and the pantograph. The input end of the pantograph is used to connect to the wire network, the output end of the pantograph is connected to the input end of the isolated DC / DC converter, and the output end of the isolated DC / DC converter is used to connect to the battery, characterized in that, The controller includes a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the control method of the dual-source trolleybus charging system according to any one of claims 1-6.

8. The dual-source trolleybus charging system according to claim 7, characterized in that, after normal charging is completed, the controller controls the pantograph to automatically retract into the top cabin.

9. The dual-source trolleybus charging system according to claim 7, characterized in that, if a fault occurs during the static charging process, after charging is stopped, the controller controls the pantograph to automatically retract into the top cabin.

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