Pure electric ship battery equalization control system based on PID algorithm

Abstract

The invention discloses a pure electric ship battery equalization control system based on a PID algorithm, and the system comprises a battery state monitoring module which is used for monitoring the state parameter of each single battery in a battery pack; the fuzzy self-adaptive PID controller is used for converting the received state parameters into PID parameter adjustment values through fuzzy control and PID control and outputting control signals; the efficient equalization module is used for evaluating the state of each single battery based on the control signal and the state parameter, and formulating an equalization strategy for battery equalization according to the state evaluation result of the single battery; the energy feedback module is used for converting redundant electric energy generated in the battery equalization process into charging electric energy of other single batteries based on an efficient DC-DC converter technology of a high-frequency transformer; and the control module is used for controlling the battery state monitoring module, the fuzzy self-adaptive PID controller, the efficient equalization module and the energy feedback module. And the battery equalization control precision and the energy recovery efficiency are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of battery equalization control, and more specifically, to a pure electric ship battery equalization control system based on the PID algorithm. Background Art

[0002] Under the trend of green environmental protection, energy conservation and emission reduction, pure electric ships have attracted much attention due to their cleanliness and high efficiency. The performance of its battery pack is related to endurance, operation stability and lifespan. As the core technology of battery management, battery equalization control is crucial for ensuring the efficient and stable operation of the battery pack. At present, the battery equalization system based on PID control is widely used in the field of pure electric ships. With its simple principle, good stability and real-time performance, it has achieved a certain degree of equalization management of the battery pack. However, with the increasing complexity of ship operating conditions, this system has frequent problems.

[0003] In terms of static parameters, the P, I, and D parameters of the traditional PID controller are no longer changed after the initial setting. When the ship is operating, the battery state is affected by factors such as different navigation stages, ambient temperature fluctuations, and changes in the load of electrical equipment. For example, when sailing out under heavy load, temperature changes during cross-regional navigation, and frequent changes in equipment load. All these make it difficult for the static parameters to adapt, resulting in poor battery equalization effect and unable to exert the best performance of the battery pack.

[0004] In terms of dynamic adjustment response, the charging and discharging process of the battery during ship operation changes rapidly. For example, during emergency acceleration and deceleration, the battery current and voltage fluctuate sharply. The traditional PID control algorithm has a response lag and cannot adjust the strategy in time according to the battery state, which exacerbates battery imbalance, reduces the overall performance of the battery, shortens the service life, and increases the operation and maintenance costs.

[0005] In terms of energy recovery, the traditional battery equalization uses methods such as resistor equalization, and a large amount of electrical energy is wasted as heat. Especially during frequent equalization operations of the ship, the energy loss is serious, reducing the energy utilization efficiency of the battery pack, limiting the endurance mileage, and hindering the popularization and application of pure electric ships.

[0006] The deficiencies of the existing pure electric ship battery equalization system based on PID control in terms of static parameter adaptability, dynamic adjustment responsiveness, and energy recovery efficiency are difficult to meet the high-performance operation requirements of ships. Therefore, a pure electric ship battery equalization control system based on the PID algorithm is needed to solve the above problems. Summary of the Invention

[0007] In view of this, the present invention provides a pure electric ship battery equalization control system based on the PID algorithm, which improves the battery equalization control accuracy and energy recovery efficiency, and comprehensively ensures the safe and stable operation of the battery.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A pure electric ship battery equalization control system based on the PID algorithm, comprising:

[0010] Battery state monitoring module: used to monitor the state parameters of each single battery in the battery pack;

[0011] Fuzzy adaptive PID controller: used to convert the received state parameters into PID parameter adjustment values through fuzzy control and PID control, and output a control signal;

[0012] High-efficiency equalization module: used to evaluate the state of each single battery based on the control signal and state parameters, and formulate an equalization strategy according to the evaluation result of the single battery state for battery equalization;

[0013] Energy feedback module: used to convert the excess electric energy generated during the battery equalization process into the charging electric energy of other single batteries based on the high-efficiency DC-DC converter technology of the high-frequency transformer;

[0014] Control module: used to control the battery state monitoring module, fuzzy adaptive PID controller, high-efficiency equalization module and energy feedback module.

[0015] Preferably, it is used to convert the received state parameters into PID parameter adjustment values through fuzzy control and PID control, and output a control signal, specifically including:

[0016] Filter the state parameters;

[0017] Fuzzify the filtered data, convert it into a fuzzy linguistic variable, and determine the membership degree values in different fuzzy sets through the membership function;

[0018] Combined with the membership degree values of the current data in each fuzzy set, determine the adjustment direction and amplitude of the PID controller parameters according to the rules defined in the fuzzy rule base, and obtain the fuzzy inference result;

[0019] Use the defuzzification algorithm to convert the fuzzy inference result into a specific numerical PID parameter adjustment value, and output a control signal.

[0020] Preferably, it is used to evaluate the state of each single battery based on the control signal and state parameters, and formulate an equalization strategy according to the evaluation result of the single battery state for battery equalization, specifically including:

[0021] Adopt a model-based evaluation method, establish a battery equivalent circuit model, and calculate the state of charge and state of health of the battery;

[0022] Judge whether the single battery needs to be equalized according to the state of charge and state of health of the battery;

[0023] If balancing is required, for the single cells with voltage higher than the threshold, the direct power feedback technology is adopted to directly transfer the excess power to the single cells with voltage lower than the threshold; for the single cells with voltage difference less than the preset difference value, that is, for the single cells with small voltage difference (the relative difference in voltage between single cells: in the battery pack, due to factors such as manufacturing process and use environment, the voltage of each single cell will vary. "Small voltage difference" means that the voltage difference between these single cells is within a relatively small range. For example, under normal working conditions, the voltage of single cells in the battery pack generally fluctuates within a certain range. If the voltages of two single cells are 3.72V and 3.75V respectively, and their difference is only 0.03V, compared with other battery pairs with larger voltage differences, this difference belongs to the smaller situation), the dynamic balancing algorithm is adopted to reasonably distribute the balancing current according to the state of charge and health state of the battery.

[0024] Preferably, the energy feedback module includes an input circuit, an output circuit, a first filter circuit, a second filter circuit and a DC-DC converter. The input circuit is respectively connected to the DC-DC converter and the first filter circuit. The DC-DC converter is connected to the output circuit, and the output circuit is connected to the second filter circuit.

[0025] Preferably, the state parameters include battery voltage, current and temperature.

[0026] Preferably, the control module is further configured to: receive the state parameters of each single cell, compare the state parameters with the battery state threshold, and determine whether the battery voltage, current or temperature exceeds the battery state threshold; and combine the battery historical data to determine the type and severity of the abnormality.

[0027] Preferably, it further includes an alarm module: used to trigger an alarm when the battery voltage, current or temperature exceeds the battery state threshold.

[0028] Preferably, to establish the battery equivalent circuit model: adopt the Thevenin model to establish the battery equivalent circuit model, and optimize and adjust the model according to the type of battery (such as lithium-ion battery, lead-acid battery, etc.) and the specific use scenario;

[0029] Calculate the state of charge (SOC) of the battery: Based on the established battery equivalent circuit model, adopt the ampere-hour integration method combined with the open-circuit voltage method to calculate the state of charge of the battery;

[0030] Calculate the state of health (SOH) of the battery: Calculate the state of health of the battery by monitoring the change of the parameters of the battery equivalent circuit model; since the internal resistance of the battery will increase with the increase of the use time and the number of charge and discharge cycles, the state of health of the battery is evaluated and calculated according to the change of the battery internal resistance.

[0031] As can be seen from the above technical solutions, compared with the prior art, the present invention discloses a pure electric ship battery equalization control system based on the PID algorithm, which has the following advantages:

[0032] (1) The present invention improves the accuracy of battery equalization control: The fuzzy adaptive PID controller innovatively combines fuzzy control and PID control. By capturing multi-dimensional state information such as battery voltage, current, and temperature in real time, it can accurately adjust the PID parameters. When the battery temperature rises, the proportional coefficient is automatically reduced to effectively avoid over-regulation. Conversely, when the temperature drops, the proportional coefficient is increased to accelerate equalization. It can also adaptively adjust when the battery charges slowly or the load changes. This greatly improves the accuracy of battery equalization control compared with traditional static parameter PID control, ensures the consistency of each single battery in the battery pack, and extends the overall service life of the battery.

[0033] (2) The present invention significantly reduces energy loss: The energy feedback module uses a DC-DC converter to cleverly convert the excess electrical energy generated during battery equalization into the charging electrical energy of other single batteries, realizing the efficient recycling of electrical energy inside the battery pack. At the same time, technologies such as high-efficiency DC-DC converters based on high-frequency transformers significantly reduce energy loss during the transmission of electrical energy, greatly improving the overall energy utilization efficiency of the battery pack, reducing energy waste, lowering the operating cost of pure electric ships, and enhancing their endurance.

[0034] (3) The present invention comprehensively ensures the safe and stable operation of the battery: The battery state monitoring module, with its integrated functions of temperature, voltage, and current monitoring, uses high-precision sensors to track the state of each single battery in real time and accurately. Once potential risks such as too high voltage or abnormal temperature occur in the battery, it can quickly issue an alarm and automatically adjust according to a preset program to ensure that the battery is always in a safe and stable working state, effectively avoiding safety accidents caused by battery failures and improving the reliability of ship operation.

[0035] (4) The present invention efficiently optimizes the equalization process: The high-efficiency equalization module can accurately judge the single battery that needs to be equalized by precisely analyzing the battery voltage and current information, avoiding the energy waste caused by traditional global equalization. When directly feeding back electrical energy, it accurately controls the flow direction of electrical energy to achieve efficient and precise battery equalization, further improving the performance and stability of the battery pack and providing strong support for the stable operation of pure electric ships. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained according to the provided drawings without creative efforts.

[0037] Figure 1 This is the principle block diagram of a pure electric ship battery equalization control system based on the PID algorithm provided by the present invention;

[0038] Figure 2 This is the schematic circuit diagram of the energy feedback module in the present invention. Specific embodiments

[0039] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0040] An embodiment of the present invention discloses a pure electric ship battery equalization control system based on the PID algorithm, as Figure 1 shown, including:

[0041] Battery state monitoring module: used to monitor the state parameters of each single battery in the battery pack, and the state parameters include battery voltage, current and temperature;

[0042] Fuzzy adaptive PID controller: used to convert the received state parameters into PID parameter adjustment values through fuzzy control and PID control, and output control signals;

[0043] High-efficiency equalization module: used to evaluate the state of each single battery based on the control signal and state parameters, and formulate an equalization strategy according to the evaluation result of the single battery state for battery equalization;

[0044] Energy feedback module: used to convert the excess electric energy generated during the battery equalization process into the charging electric energy of other single batteries based on the high-efficiency DC-DC converter technology of the high-frequency transformer;

[0045] Control module: used to control the battery state monitoring module, fuzzy adaptive PID controller, high-efficiency equalization module and energy feedback module to improve the performance of the battery management system.

[0046] Specifically, the battery state monitoring module integrates temperature, voltage and current monitoring functions, and real-time collects the state parameter data of each single battery in the battery pack through high-precision sensors, and transmits the data to the fuzzy adaptive PID controller; at the same time, transmits the battery pack state parameter data to the control unit, and the control unit compares the state parameters with the battery state threshold to judge whether the battery voltage, current or temperature exceeds the battery state threshold; and combines the battery historical data to judge the type and severity of the abnormality.

[0047] The fuzzy adaptive PID controller combines fuzzy control and PID control. During the operation of the system, it can automatically adjust the P (proportional), I (integral), and D (derivative) parameters of PID according to the real-time acquired state information such as battery voltage, current, and temperature, so as to achieve precise battery equalization control. When the battery temperature rises, it can automatically reduce the proportional coefficient to avoid over-regulation.

[0048] Specifically, it includes:

[0049] Filter the state parameters;

[0050] Fuzzify the filtered data, convert it into fuzzy language variables, and determine the membership values in different fuzzy sets through the membership function;

[0051] Combined with the membership values of the current data in each fuzzy set, determine the adjustment direction and amplitude of the PID controller parameters according to the rules defined in the fuzzy rule base to obtain the fuzzy inference result;

[0052] Use the defuzzification algorithm to convert the fuzzy inference result into a specific numerical PID parameter adjustment value and output the control signal.

[0053] The high-efficiency equalization module, during the battery equalization process, combines the battery voltage and current information to accurately judge the battery cells that need to be equalized, avoiding the energy waste caused by global equalization. For the single battery cells with too high voltage, the direct power feedback technology is adopted. By precisely controlling the on and off of the power switch devices and using the pulse width modulation (PWM) technology, the excess electric energy is directly transmitted to the single battery cells with lower voltage. For the batteries with small voltage differences, the dynamic equalization algorithm is adopted to reasonably distribute the equalization current according to the SOC and SOH of the batteries to achieve high-efficiency equalization and reduce the energy loss of the battery pack.

[0054] When the high-efficiency equalization module of the present invention realizes battery equalization, it accurately determines the battery cells that need to be equalized according to the battery voltage and current information, avoids unnecessary global equalization operations, and effectively reduces energy waste. During the direct power feedback process, it can accurately control the power flow direction to ensure efficient and accurate realization of battery equalization.

[0055] Such as Figure 2 As shown, the energy feedback module includes a DC-DC converter. The energy feedback module uses the energy feedback technology to convert the excess electric energy generated during the battery equalization process into the charging electric energy of other single battery cells through the DC-DC converter, realizing the recycling of electric energy inside the battery pack, reducing energy loss, and improving the overall energy utilization efficiency of the battery pack. The high-efficiency DC-DC converter technology based on high-frequency transformers is adopted to reduce the loss during the electric energy transmission process;

[0056] The energy feedback module also includes an input-output circuit: The input circuit is connected to the single battery with a higher voltage and surplus electric energy in the battery pack. The first filter circuit composed of filter capacitor 1 and inductor 1 can effectively filter out the high-frequency clutter in the input electric energy, ensure the purity and stability of the electric energy entering the DC-DC converter, prevent the clutter from interfering with the normal operation of the converter, and reduce the conversion efficiency and damage risk. The output circuit is connected to other single batteries to be charged. The output circuit is also connected with the second filter circuit composed of filter capacitor 2 and inductor 2, which further filters and stabilizes the electric energy output by the DC-DC converter, outputs smooth and stable charging electric energy, protects the battery to be charged, and avoids battery damage caused by voltage fluctuation.

[0057] The DC-DC converter in the energy feedback module of the present invention can stably and efficiently convert the surplus electric energy in the equalization process into the charging electric energy acceptable to other single batteries, ensuring the reliability of the 80FD energy feedback process; the design of the high-efficiency converter can effectively reduce the loss of energy in the conversion process and improve the overall operation efficiency of the system.

[0058] When the DC-DC converter converts electric energy, heat will be generated due to power loss. If the heat is not dissipated in time, it will affect the performance and reliability. Therefore, a heat dissipation device needs to be set. The heat sink is generally made of a metal material with a high thermal conductivity coefficient. By increasing the surface area, the heat dissipation is accelerated. The cooling fan is installed near the heat sink and automatically adjusts the rotation speed according to the temperature of the DC-DC converter. When the temperature is high, it runs at an accelerated speed to enhance the air flow and improve the heat dissipation effect, ensuring the efficient operation of the DC-DC converter at an appropriate temperature.

[0059] Control and communication module: The control module receives the data such as battery voltage, current, temperature, etc. transmitted by the battery status monitoring module, as well as the control instructions issued by the fuzzy adaptive PID controller. After analysis and processing, it sends a PWM signal to the DC-DC converter to accurately adjust its working state and achieve precise control of the electric energy conversion. The communication interface circuit supports two-way communication between the energy feedback module and other system modules, can upload the working parameters of the DC-DC converter, such as conversion efficiency, output voltage and current, etc., and at the same time receive the control commands and battery status feedback issued by other modules to ensure the coordinated operation of the entire system.

[0060] In the specific implementation process of the battery equalization control system for pure electric ships, each module closely cooperates and operates orderly according to the logic of data transmission and processing to achieve efficient battery equalization control. The following is the technical implementation process of the battery equalization control system for pure electric ships:

[0061] 1. The battery status monitoring module collects data: The battery status monitoring module is at the start of the entire process. Using high-precision voltage sensors, current sensors, and temperature sensors, it collects the voltage, current, and temperature of each single battery in real time. The sensors are distributed in a layout that can comprehensively and accurately obtain the status information of the battery pack. To ensure the collection accuracy, the sensors are regularly calibrated and compensated to eliminate errors. The collected data is transmitted through a high-speed communication bus (CAN bus or FlexRay bus).

[0062] 2. The data is transmitted to the fuzzy adaptive PID controller: The battery status monitoring module transmits the collected battery status data to the fuzzy adaptive PID controller. During the transmission process, data compression and encryption technologies are used to reduce the amount of data transmitted and improve the security and reliability of the transmission.

[0063] 3. The fuzzy adaptive PID controller processes data and adjusts parameters: After receiving the data, the fuzzy adaptive PID controller first filters it to remove noise interference and uses the Kalman filter algorithm to perform an optimal estimate of the battery status. Then, it performs fuzzification, converting the battery status data into fuzzy linguistic variables. For example, the temperature is divided into fuzzy sets such as "low temperature", "normal temperature", "high temperature", etc., and the degree to which the current temperature belongs to each fuzzy set is determined through the membership function. After that, reasoning is carried out based on the preset fuzzy rule base. For example, when the temperature rises and is in the "high temperature" fuzzy set, the adjustment direction and amplitude of the proportionality coefficient are determined according to the rule "if the temperature is high, then reduce the proportionality coefficient". Finally, the defuzzification algorithm (such as the centroid method) is used to convert the fuzzy inference result into a specific PID parameter adjustment value, realizing the real-time optimization of the PID controller parameters and outputting a precise control signal.

[0064] 4. The fuzzy adaptive PID controller collaborates with the high-efficiency equalization module: The control signal output by the fuzzy adaptive PID controller is transmitted to the high-efficiency equalization module. The high-efficiency equalization module combines the battery voltage and current information it obtains to evaluate the status of each single battery. Using a model-based evaluation method, an equivalent circuit model of the battery is established to calculate the state of charge (SOC) and state of health (SOH) of the battery, and accurately determine whether the battery needs to be equalized.

[0065] 5. The high-efficiency balancing module performs balancing operations: Based on the evaluation results of the individual battery states, the high-efficiency balancing module formulates personalized balancing strategies. For individual batteries with too high voltage, the direct power feedback technology is adopted to directly transfer the excess power to the individual batteries with lower voltage; for batteries with small voltage differences, the dynamic balancing algorithm is used to reasonably distribute the balancing current according to the SOC and SOH of the batteries. During the direct power feedback process, by precisely controlling the conduction and cutoff of the power switch devices (the power switch devices belong to the high-efficiency balancing module), the pulse width modulation (PWM) technology is used to adjust the power transmission power and time, so as to achieve precise power transmission and control.

[0066] 6. The energy feedback module recovers and converts electrical energy: During the battery balancing process, the energy feedback module monitors the changes in battery voltage and current in real time. When it detects that a certain individual battery has excess electrical energy, it quickly activates the energy capture mechanism. Using a DC-DC converter (a bidirectional DC-DC converter is used to improve the flexibility of energy conversion), the excess electrical energy is converted from the voltage level of the high-voltage individual battery to a voltage level suitable for charging other low-voltage individual batteries. The converted electrical energy is first stored in a small energy storage unit (such as a supercapacitor or a small battery pack) for buffering, and then, according to the actual needs of each individual battery in the battery pack, it is precisely distributed to the individual batteries that need to be charged through an intelligent distribution algorithm, realizing the efficient recycling of electrical energy within the battery pack.

[0067] 7. Each module cooperates to ensure the safe and stable operation of the battery: When the control module monitors that the battery voltage, temperature, or current exceeds the preset normal range, it immediately triggers an alarm. An intelligent diagnostic algorithm is used to analyze and diagnose abnormal conditions by combining the battery historical data and the real-time state, and to judge the type and severity of the abnormality. According to the abnormal detection results, the system automatically starts the corresponding adjustment measures, and the adjustments are as follows:

[0068] Adjustment when the battery temperature is too high: When the control module monitors that the battery temperature is too high and reaches the preset temperature threshold, it will automatically start the cooling fan. The cooling fan helps the heat-generating components such as the DC-DC converter to dissipate heat by accelerating the air flow. Generally, the rotation speed of the cooling fan is adjusted according to the degree to which the temperature exceeds the threshold. The higher the temperature, the faster the fan speed, so as to ensure that the relevant components work at an appropriate temperature and avoid affecting the battery performance and safety due to high temperature;

[0069] Adjustment when the battery voltage is too high: If the battery voltage exceeds the normal range, the control module will take corresponding measures. For the battery during charging, the charging current will be adjusted to reduce the charging speed and prevent overcharging of the battery; in severe cases, the charging operation will even be stopped. During the battery equalization process, when the voltage of a single battery is too high, the high-efficiency equalization module will, according to the preset equalization strategy, use the direct electric energy feedback technology to transfer the excess electric energy to the single battery with a lower voltage by controlling the power switch device, so as to balance the voltage of each single battery in the battery pack;

[0070] Adjustment for comprehensive abnormal situations: The control module combines the battery historical data and the real-time status, and uses an intelligent diagnostic algorithm to judge the type and severity of the abnormality. For minor abnormalities, the system may only make minor adjustments, such as fine-tuning the charging parameters or starting mild heat dissipation measures; while for severe abnormalities, more strict control means will be taken, such as cutting off the connection of some batteries to avoid the spread of faults, and at the same time sending an alarm to notify the operator to handle it in time.

[0071] In the battery equalization control system of pure electric ships, the control and communication module and the energy feedback module cooperate closely, and their working sequence and process are as follows:

[0072] The control and communication module receives data: The control module first receives the data such as battery voltage, current, temperature, etc. transmitted by the battery status monitoring module, as well as the control instructions issued by the fuzzy adaptive PID controller. These data and instructions are the basis for the subsequent operations of the entire system and provide a basis for precise control of electric energy conversion.

[0073] The energy feedback module monitors in real time: During the battery equalization process, the energy feedback module continuously monitors the changes in battery voltage and current in real time. It is always in a working state and continuously collects battery status information to detect battery abnormalities or excess electric energy in a timely manner.

[0074] The energy feedback module starts energy capture: When the energy feedback module detects that a single battery has excess electric energy, it quickly starts the energy capture mechanism. This is a key step in energy recovery, which means that the system starts to process the excess electric energy and prepares for subsequent conversion and reuse.

[0075] The control and communication module adjusts the DC-DC converter: After receiving the relevant data and instructions and analyzing and processing them, the control module sends a PWM signal to the DC-DC converter. The working state of the DC-DC converter is accurately adjusted through this PWM signal to achieve precise control of electric energy conversion. This step is closely related to the energy feedback module because the DC-DC converter is the core component for electric energy conversion in the energy feedback module, and the precise adjustment of the control module directly affects the efficiency and effect of energy feedback.

[0076] The energy feedback module converts and distributes electrical energy: The energy feedback module uses a DC-DC converter (a bidirectional DC-DC converter is adopted to improve the flexibility of energy conversion) to convert the excess electrical energy from the voltage level of the high-voltage single battery to a voltage level suitable for charging other low-voltage single batteries. The converted electrical energy is first stored in a small energy storage unit (such as a supercapacitor or a small battery pack) for buffering, and then, according to the actual demands of each single battery in the battery pack, it is accurately distributed to the single batteries that need to be charged through an intelligent distribution algorithm, realizing the efficient recycling of electrical energy within the battery pack. In this process, the stable operation of the DC-DC converter depends on the precise regulation of the control module, and the two cooperate with each other to complete the entire process of energy feedback.

[0077] The various embodiments in this specification are described in a progressive manner. Each embodiment focuses on the differences from other embodiments. For the same or similar parts among the various embodiments, reference can be made to each other. For the devices disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple. For the relevant parts, reference can be made to the description in the method part.

[0078] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery balancing control system for pure electric ships based on PID algorithm, characterized in that: include: Battery status monitoring module: used to monitor the status parameters of each single cell in the battery pack; Fuzzy adaptive PID controller: used to convert the received state parameters into PID parameter adjustment values ​​through fuzzy control and PID control, and output control signals; High-efficiency balancing module: used to evaluate the status of each single cell based on the control signal and status parameters, and formulate a balancing strategy for battery balancing based on the evaluation results of the single cell status; Energy feedback module: It is used to convert the excess power generated during the battery balancing process into charging power for other single cells using high-efficiency DC-DC converter technology based on high-frequency transformers; Control module: used to control the battery status monitoring module, fuzzy adaptive PID controller, high-efficiency balancing module and energy feedback module.

2. A battery balancing control system for pure electric ships based on PID algorithm according to claim 1, characterized in that: It is used to convert the received state parameters into PID parameter adjustment values ​​through fuzzy control and PID control, and output control signals, specifically including: Filtering the state parameters; The filtered data is fuzzified and converted into fuzzy linguistic variables, and the membership values ​​in different fuzzy sets are determined through membership functions; Combined with the membership values ​​of the current data in each fuzzy set, the adjustment direction and amplitude of the PID controller parameters are determined according to the rules defined in the fuzzy rule base to obtain the fuzzy reasoning results; The defuzzification algorithm is used to convert the fuzzy reasoning results into specific numerical PID parameter adjustment values ​​and output control signals.

3. A battery balancing control system for pure electric ships based on PID algorithm according to claim 1, characterized in that: It is used to evaluate the status of each single cell based on the control signal and status parameters, and formulate a balancing strategy for battery balancing according to the evaluation results of the single cell status, including: Using a model-based evaluation method, a battery equivalent circuit model is established to calculate the battery state of charge and battery health status; Determine whether the single cell needs to be balanced based on the battery state of charge and battery health status; If balancing is required, for cells with voltages higher than the threshold, direct power feedback technology is used to transfer excess power directly to cells with voltages lower than the threshold. For cells with voltage differences less than the preset difference value, a dynamic balancing algorithm is used to reasonably allocate the balancing current based on the battery's state of charge and health status.

4. A battery balancing control system for pure electric ships based on PID algorithm according to claim 1, characterized in that: The energy feedback module includes an input circuit, an output circuit, a first filter circuit, a second filter circuit and a DC-DC converter. The input circuit is connected to the DC-DC converter and the first filter circuit respectively, the DC-DC converter is connected to the output circuit, and the output circuit is connected to the second filter circuit.

5. A battery balancing control system for pure electric ships based on PID algorithm according to claim 1, characterized in that: Status parameters include battery voltage, current and temperature.

6. A battery balancing control system for pure electric ships based on PID algorithm according to claim 5, characterized in that: The control module is also used to: receive the status parameters of each single battery, and compare the status parameters with the battery status threshold to determine whether the battery voltage, current or temperature exceeds the battery status threshold; and determine the type and severity of the abnormality in combination with the battery historical data.

7. A battery balancing control system for pure electric ships based on PID algorithm according to claim 6, characterized in that: Also included is an alarm module: used to trigger an alarm when the battery voltage, current or temperature exceeds the battery status threshold.

8. A battery balancing control system for pure electric ships based on PID algorithm according to claim 3, characterized in that: The battery equivalent circuit model is established as follows: The Thevenin model is used to establish a battery equivalent circuit model, and the model is optimized and adjusted according to the battery type and specific usage scenarios; Based on the established battery equivalent circuit model, the battery state of charge is calculated using the ampere-hour integration method combined with the open circuit voltage method; The battery health status is calculated by monitoring the change of the battery internal resistance of the battery equivalent circuit model.

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