TWI879297B - Control method and control system for hybrid electric systems - Google Patents

Abstract

A control method and a control system for hybrid electric systems are provided. The hybrid electric system comprises a battery module and a fuel cell module. The control method comprises the following steps. Detect the state of charge of the battery module to generate an initial power generation value of the fuel cell module according to the state of charge of the battery module. Detect the state of health of the battery module to generate a first adjustment factor. Detect the voltage value and temperature value of at least one cell included in the battery module to generate a second adjustment factor according to the voltage value and temperature value of the at least one cell. Adjust the initial power generation value of the fuel cell module based on the first adjustment factor and the second adjustment factor to generate an adjusted power generation value of the fuel cell module. Control the fuel cell module to generate power with the adjusted power generation value.

Description

Control method and control system applicable to hybrid electric power system

The present disclosure relates to a control method and a control system, and in particular to a control method and a control system applicable to a hybrid power system.

Today's battery vehicles are equipped with batteries as the main driving force for the motor. However, after a period of use, the battery cells will begin to age, resulting in a reduction in mileage. Therefore, how to take care of the health of aged batteries is a goal that the industry has been working hard on.

In view of the prior art, the present disclosure proposes a control method and a control system applicable to a hybrid power system to take into account the health of an aged battery.

According to one aspect of the present disclosure, a control method is proposed, which is applicable to a hybrid power system. The hybrid power system includes a first battery and a second battery. The control method includes the following steps: detecting the remaining power of the first battery to generate an initial power generation value of the second battery according to the remaining power of the first battery; detecting the health status of the first battery to generate a first correction factor according to the health status of the first battery; detecting the voltage value and temperature value of at least one battery cell included in the first battery to generate a second correction factor according to the voltage value and temperature value of at least one battery cell; adjusting the initial power generation value of the second battery based on the first correction factor and the second correction factor to generate a power generation correction value of the second battery; and controlling the second battery to generate power at the power generation correction value of the second battery.

According to another aspect of the present disclosure, a control system is provided, which is applicable to a hybrid power system. The hybrid power system includes a first battery and a second battery. The control system includes a battery management module, a control module, and a power control module, wherein the control module is coupled to the battery management module, and the power control module is coupled to the control module. The battery management module is used to detect the remaining power of the first battery, the health status of the first battery, and the voltage value and temperature value of at least one battery cell included in the first battery. The control module is used to generate an initial power generation value of the second battery according to the remaining power of the first battery, generate a first correction factor according to the health status of the first battery, generate a second correction factor according to the voltage value and temperature value of at least one battery cell, and adjust the initial power generation value of the second battery based on the first correction factor and the second correction factor to generate a power generation correction value of the second battery. The power control module is used to control the second battery to generate power at the initial power generation value or the power generation correction value of the second battery.

In order to better understand the above and other aspects of the present disclosure, embodiments are specifically described below with reference to the accompanying drawings.

The technical terms in this specification refer to the customary terms in this technical field. If this specification explains or defines some terms, the interpretation of these terms shall be subject to the explanation or definition in this specification. Each embodiment of the present disclosure has one or more technical features. Under the premise of possible implementation, a person with ordinary knowledge in this technical field may selectively implement part or all of the technical features in any embodiment, or selectively combine part or all of the technical features in these embodiments. Any easy substitution, modification, and equivalent changes of any of the embodiments are included in the scope of the present disclosure and shall be subject to the subsequent patent scope.

The following discloses many different implementation methods or examples to implement different features of the present invention. The following describes specific elements and their arrangement examples to illustrate the present invention. Of course, these are only examples and do not limit the scope of the present invention. Furthermore, it should be understood that there may be additional operating steps before, during or after the method is performed, and some of the operating steps described may be replaced or deleted in the methods of other embodiments.

Please refer to Figures 1 and 2. Figure 1 shows a flow chart of a control method S according to an embodiment of the present disclosure, and Figure 2 shows a block diagram of a hybrid power system 10 and a control system 100 according to an embodiment of the present disclosure. The control system 100 and the control method S are applicable to the hybrid power system 10.

As shown in FIG. 2 , the hybrid power system 10 may include a first battery 11, a second battery 12, an inverter 13, and a motor module 14 that are coupled to each other. The hybrid power system 10 may be applied to an electric vehicle, in which case the entire vehicle driving power of the electric vehicle is jointly supplied by the first battery 11 and the second battery 12. The first battery 11 and the second battery 12 are different types of batteries, so it is called a hybrid power. In this embodiment, the first battery 11 is a storage battery, more specifically, a lithium battery; and the second battery 12 is a fuel cell, more specifically, a hydrogen fuel cell, so that the fuel cell can be used to generate electricity to supply power to the storage battery. That is, the second battery 12 can be used as a power generation device to supply power to the first battery 11 and the inverter 13. The first battery 11 can store electricity and supply power to the inverter 13. The inverter 13 can convert the DC power of the first battery 11 and the second battery 12 into AC power to drive the motor module 14.

The control system 100 and control method S applicable to the hybrid power system 10 of the disclosed embodiment are intended to suppress the continuous deterioration of the first battery 11 and take into account the life of the battery cells contained in the first battery 11, so as to further maintain the driving performance of the electric vehicle using the hybrid power system 10, that is, to prevent the battery cells of the degraded first battery 11 from being continuously damaged.

As shown in FIG. 2 , the control system 100 may include a battery management module 110, a control module 120, and a power control module 130, wherein the control module 120 is coupled to the battery management module 110, and the power control module 130 is coupled to the control module 120. In the present embodiment, the battery management module 110, the control module 120, and the power control module 130 may be implemented, for example, by using a chip, a circuit block in a chip, a firmware circuit, or a circuit board including a plurality of electronic components and wires.

As shown in FIG. 1, the control method S includes, for example, sequential steps S110 to S150. In step S110, the remaining power (state of charge, SOC) of the first battery 11 is detected to generate the initial power generation value of the second battery 12 according to the remaining power of the first battery 11. The battery management module 110 can be used to detect the remaining power of the first battery 11, and the control module 120 can be used to generate the initial power generation value of the second battery 12 according to the remaining power of the first battery 11. Please refer to FIG. 3, which shows a relationship diagram between the remaining power of the first battery 11 and the power generation power of the second battery 12. The control module 120 can configure the initial power generation value of the second battery 12 according to this relationship diagram. For example, when the battery management module 110 detects that the remaining power of the first battery 11 is 50% (i.e., SOC=50%), and transmits the remaining power information to the control module 120, the control module 120 configures 30 kilowatts (kW) of power generation according to the 50% remaining power to generate the power generation initial value of the second battery 12. The power control module 130 can be used to control the second battery 12 to generate power at the second battery 12's initial power generation value.

In step S120, the state of health (SOH) of the first battery 11 is detected to generate a first correction factor according to the SOH of the first battery 11. The battery management module 110 may be used to detect the SOH of the first battery 11, and the control module 120 may be used to generate a first correction factor according to the SOH of the first battery 11. Please refer to FIG. 4, which shows a relationship diagram between the SOH of the first battery 11 and the first correction factor, and the control module 120 may set the first correction factor according to the relationship diagram. For example, when the battery management module 110 detects that the health status of the first battery 11 is 50% (i.e., SOH=50%), and transmits the health status information to the control module 120, the control module 120 sets the first correction factor to 1.5 according to the health status of 50% to generate the first correction factor. The first correction factor is a gain, that is, an amplification factor.

In step S130, the voltage value and temperature value of at least one battery cell included in the first battery 11 are detected to generate a second correction factor according to the voltage value and temperature value of at least one battery cell. The first battery 11 may include a plurality of battery cells, and a battery cell is a single battery structure. The battery management module 110 may be used to detect the voltage value and temperature value of the battery cell of the first battery 11, and the control module 120 may be used to generate a second correction factor according to the voltage value and temperature value of the battery cell of the first battery 11. Please refer to FIG. 5, which shows a setting block diagram of the second correction factor corresponding to the voltage value and temperature value of the battery cell of the first battery 11. The control module 120 can set the second correction factor according to this setting block diagram. As shown in FIG. 5 , the region formed by the voltage value of the battery cell of the first battery 11 as the horizontal axis and the temperature value of the battery cell of the first battery 11 as the vertical axis is divided into four blocks, namely the first block Z1, the second block Z2, the third block Z3 and the fourth block Z4.

In response to the principle that a battery cell with a high detected voltage and low temperature is at a lower level of aging, each block may correspond to a different setting value of the second correction factor. The first block Z1 corresponds to the battery cells of the first battery 11 with moderate aging (high temperature value, but high voltage value), so it can be set to 20 kilowatts (kW), for example; the second block Z2 corresponds to the battery cells of the first battery 11 with high aging (low voltage value and high temperature value), so it can be set to 30 kilowatts (kW), for example; the third block Z3 corresponds to the battery cells of the first battery 11 with moderate aging (low voltage value, but low temperature value), so it can be set to 20 kilowatts (kW), for example; the fourth block Z4 corresponds to the battery cells of the first battery 11 with low aging (high voltage value and low temperature value), so it can be set to 10 kilowatts (kW), for example.

For example, when the battery management module 110 detects that the voltage value of a relatively deteriorated battery cell of the first battery 11 is 2.8V and the temperature value is 25°C, the information of the voltage value and the temperature value is transmitted to the control module 120. According to the setting block diagram shown in FIG. 5, the coordinates of the voltage value of 2.8V and the temperature value of 25°C are located in the third block Z3, and the control module 120 uses the setting value of 20 kilowatts (kW) corresponding to the third block Z3 as the second correction factor. The second correction factor is an offset value, that is, a compensation parameter.

In one embodiment, the battery management module 110 can be used to detect the voltage values and temperature values of multiple or even all battery cells of the first battery 11, and the control module 120 can take out the top ten lowest voltage values and the top ten highest temperature values, and obtain an average voltage value of the top ten lowest voltage values and an average temperature value of the top ten highest temperature values, and generate a second correction factor based on the average voltage value and the average temperature value. It should be noted that even if the average of multiple voltage values and multiple temperature values is taken, the control module 120 still follows the setting block diagram shown in FIG. 5 to determine in which block the average voltage value and the average temperature value are located to generate the second correction factor. For example, the average voltage value of the multiple voltage values is 3.2V and the average temperature value of the multiple temperature values is 28°C. According to the setting block diagram shown in Figure 5, the coordinates of the voltage value of 3.2V and the temperature value of 28°C are located in the fourth block Z4. The control module 120 uses the setting value of 10 kilowatts (kW) corresponding to the fourth block Z4 as the second correction factor.

In another embodiment, the battery management module 110 can be used to detect the voltage values and temperature values of multiple or even all battery cells of the first battery 11, and the control module 120 can obtain the lowest voltage value among the detected voltage values and the highest temperature value among the detected temperature values, and generate the second correction factor according to the lowest voltage value and the highest temperature value. It should be noted that the control module 120 still follows the setting block diagram shown in FIG. 5 to determine in which block the lowest voltage value and the highest temperature value are located to generate the second correction factor. For example, the lowest voltage value among the detected voltage values is 2.6V and the highest temperature value among the detected temperature values is 38°C. According to the setting block diagram shown in FIG. 5, the coordinates of the voltage value of 2.6V and the temperature value of 38°C are located in the second block Z2. The control module 120 uses the setting value of 30 kilowatts (kW) corresponding to the second block Z2 as the second correction factor.

In step S140, the initial power generation value of the second battery 12 is adjusted based on the first correction factor and the second correction factor to generate the power generation correction value of the second battery 12. The control module 120 can be used to adjust the initial power generation value of the second battery 12 based on the first correction factor and the second correction factor to generate the power generation correction value of the second battery 12. As mentioned above, the first correction factor is a gain, and the second correction factor is an offset value. Thus, the control module 120 can generate the power generation correction value of the second battery 12 by multiplying the initial power generation value of the second battery 12 by the gain and then adding the offset value. For example, when the initial power generation value of the second battery 12 is 30 kilowatts (kW), the first correction factor is 1.5, and the second correction factor is 20 kilowatts (kW), that is, the power generation correction value of the second battery 12 is 30*1.5+20=65 kilowatts (kW), which serves as a correction command for the new power generation power of the second battery 12.

In step S150, the second battery 12 is controlled to generate electricity with the power generation correction value of the second battery 12. After the control module 120 generates the power generation correction value of the second battery 12, the power control module 130 is commanded to modify the power generation power of the second battery 12. The power control module 130 can be used to control the second battery 12 to generate electricity with the power generation correction value of the second battery 12. For example, when the power generation correction value of the second battery 12 is generated as 65 kilowatts (kW), the power control module 130 can control the second battery 12 to switch from the initial power generation value of 30 kilowatts (kW) to the power generation correction value of 65 kilowatts (kW) to generate electricity.

According to the above, the control method and control system for hybrid power system proposed in the disclosed embodiment adjust the control of the power generation of the second battery (fuel cell) by setting the first correction factor and the second correction factor, thereby sharing the power output of the first battery (storage battery). Therefore, when applied to electric vehicles, the control method and control system of the disclosed embodiment can avoid the decline of the driving performance of the electric vehicle, and inhibit the degradation of its first battery (storage battery), and take into account the health of the battery cells of the degraded first battery, thereby slowing down the rapid damage of the battery cells of the first battery.

Although the present disclosure has been disclosed as above by way of embodiments, it is not intended to limit the present disclosure. A person with ordinary knowledge in the technical field to which the present disclosure belongs may make various changes and modifications without departing from the spirit and scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the scope defined by the attached patent application.

10: Hybrid power system 11: First battery 12: Second battery 13: Inverter 14: Motor module 100: Control system 110: Battery management module 120: Control module 130: Power control module S: Control method S110~S150: Steps Z1: First block Z2: Second block Z3: Third block Z4: Fourth block

FIG. 1 is a flow chart of a control method according to an embodiment of the present disclosure. FIG. 2 is a block diagram of a control system according to an embodiment of the present disclosure. FIG. 3 is a diagram showing a relationship between the remaining power of a first battery of a hybrid power system and the power generation of a second battery of the hybrid power system. FIG. 4 is a diagram showing a relationship between the health status of a first battery of a hybrid power system and a first correction factor. FIG. 5 is a block diagram showing a setting of a voltage value and a temperature value of a battery cell of a first battery of a hybrid power system corresponding to a second correction factor.

S: Control method

S110~S150: Steps

Claims (10)

A control method is applicable to a hybrid power system, wherein the hybrid power system includes a first battery and a second battery, and the control method includes the following steps: Detecting the remaining power of the first battery to generate an initial power generation value of the second battery according to the remaining power of the first battery; Detecting the health status of the first battery to generate a first correction factor according to the health status of the first battery; Detecting the voltage value and temperature value of at least one battery cell included in the first battery to generate a second correction factor according to the voltage value and temperature value of the at least one battery cell; Adjusting the initial power generation value of the second battery based on the first correction factor and the second correction factor to generate a power generation correction value of the second battery; and Controlling the second battery to generate power at the power generation correction value of the second battery. In the control method as described in claim 1, the first battery is coupled to the second battery, the first battery is a storage battery, and the second battery is a fuel cell, and the fuel cell is used to generate electricity to supply power to the storage battery. The control method as described in claim 1, wherein the first battery includes a plurality of battery cells, and the step of "detecting the voltage value and temperature value of at least one battery cell included in the first battery to generate the second correction factor according to the voltage value and temperature value of the at least one battery cell" includes: Detecting the voltage value and temperature value of the battery cells to extract the first few low multiple voltage values and the first few high multiple temperature values, and obtain a corresponding average voltage value and an average temperature value; and Generating the second correction factor according to the average voltage value and the average temperature value. The control method as described in claim 1, wherein the first battery includes a plurality of battery cells, and the step of "detecting the voltage value and temperature value of at least one battery cell included in the first battery to generate the second correction factor according to the voltage value and temperature value of the at least one battery cell" includes: Detecting the voltage value and temperature value of the battery cells to obtain a minimum voltage value and a maximum temperature value, and generating the second correction factor according to the minimum voltage value and the maximum temperature value. The control method as described in claim 1, wherein the first correction factor is a gain, and the second correction factor is an offset value, and the step of "adjusting the initial power generation value of the second battery based on the first correction factor and the second correction factor to generate the power generation correction value of the second battery" includes: Multiplying the initial power generation value of the second battery by the gain and then adding the offset value to generate the power generation correction value of the second battery. A control system is applicable to a hybrid power system, wherein the hybrid power system includes a first battery and a second battery, and the control system includes: A battery management module, used to detect the remaining power of the first battery, the health status of the first battery, and the voltage value and temperature value of at least one battery cell included in the first battery; A control module, coupled to the battery management module, and used to generate an initial power generation value of the second battery according to the remaining power of the first battery, generate a first correction factor according to the health status of the first battery, generate a second correction factor according to the voltage value and temperature value of the at least one battery cell, and adjust the initial power generation value of the second battery based on the first correction factor and the second correction factor to generate a power generation correction value of the second battery; and A power control module is coupled to the control module and is used to control the second battery to generate electricity with the power generation correction value of the second battery. A control system as described in claim 6, wherein the first battery is coupled to the second battery, the first battery is a storage battery, and the second battery is a fuel cell, and the fuel cell is used to generate electricity to supply power to the storage battery. A control system as described in claim 6, wherein the first battery includes a plurality of battery cells, the battery management module is used to detect the voltage values and temperature values of the battery cells, the control module is used to retrieve the first few lowest multiple voltage values and the first few highest multiple temperature values, and obtain a corresponding average voltage value and an average temperature value, and generate the second correction factor based on the average voltage value and the average temperature value. A control system as described in claim 6, wherein the first battery includes a plurality of battery cells, the battery management module is used to detect voltage values and temperature values of the battery cells, the control module is used to obtain a minimum voltage value and a maximum temperature value, and generate the second correction factor based on the minimum voltage value and the maximum temperature value. A control system as described in claim 6, wherein the first correction factor is a gain, the second correction factor is an offset value, and the control module is used to multiply the initial power generation value of the second battery by the gain and then add the offset value to generate the power generation correction value of the second battery.

Images