CN204674395U - Based on the dual energy source electric car energy management system of predictive control - Google Patents

Abstract

The utility model discloses an energy management system for an electric vehicle with dual energy sources based on predictive control, which comprises a power battery, a supercapacitor, an energy predictive control module and an energy bidirectional supply module. unit, energy prediction area processing unit, variable comparison unit, and battery power distribution unit, and the bidirectional energy supply module includes a microprocessing control unit, a battery monitoring unit, a DC-DC bidirectional converter and a capacitor control unit, and the microprocessing control unit is connected with the battery monitoring unit respectively The unit and the capacitor control unit are electrically connected, the control signal of the battery monitoring unit is connected to the power battery, and the control signal of the capacitor control unit is connected to the supercapacitor and the DC-DC bidirectional converter. The flow distribution is unreasonable, the utilization rate is not high, and the problem of efficient energy control and management cannot be realized.

Description

Energy management system for electric vehicles with dual energy sources based on predictive control

technical field

The utility model relates to the technical field of electric vehicles.

Background technique

Electric vehicles have the characteristics of environmental protection, energy saving and high energy conversion efficiency. Pure electric and hybrid vehicles with electric drive devices are an important development direction of new energy vehicles in the future. The key issue of energy saving for electric vehicles is to optimize the management of energy distribution among electric drive devices, energy storage devices and auxiliary power units, especially the optimal configuration of energy storage and release of different types of energy storage devices.

There are two basic structures of the existing electric vehicle energy supply system: one is a hybrid electric vehicle (that is, a PLUG-IN electric vehicle), and there are three energy sources for this vehicle, namely, the chemical energy of the fuel provided by the heat engine. , the energy stored by the energy storage device (which can come from the grid power supply, the on-board engine/generator system or the energy recovery system) and the recovered vehicle kinetic energy. The other is a pure electric vehicle with an energy recovery system. There are two energy sources for this vehicle, one is the power supply of the grid, and the other is the kinetic energy of the car when braking, decelerating or going downhill. Compared with the structure of hybrid electric vehicles, pure electric vehicles have the advantages of no pollutant emissions, simple structure, high efficiency, and low cost. The most commonly used energy storage device in the existing pure electric vehicles is the power battery, which provides energy for the traction motor and headlights of the electric vehicle. However, because the energy carried by the power battery is limited, when the vehicle is accelerating or climbing However, when the existing pure electric vehicles require high power for starting and accelerating or decelerating and braking, the distribution and utilization of energy cannot be reasonably controlled, resulting in the loss of power batteries of pure electric vehicles. The energy utilization rate is low, which brings inconvenience to the normal driving of the vehicle. In order to realize the maximum utilization of energy and increase the mileage of the car, it is necessary to effectively monitor and control the work of each energy conversion device so that the energy in the energy system Get a reasonable allocation to achieve the best flow of pure electric vehicle energy.

At present, there are relatively few technologies on the dual energy source management system of pure electric vehicles, and the existing research on dual energy sources mainly focuses on the energy system of fuel cell vehicles or hybrid electric vehicles. In these occasions, the dual energy source system works as an auxiliary system and does not have high requirements for control. Most of them directly analyze its working mode, and then set simple control rules according to the working mode, without systematically addressing energy management issues. It is stated that the distribution of energy flow in the energy system is unreasonable, the utilization rate is not high, and the efficient energy control and management of pure electric vehicles with dual energy sources cannot be realized. In pure electric vehicles, the dual energy source is the main energy source, and its control performance directly determines the acceleration performance and economic performance of the vehicle.

Utility model content

The purpose of this utility model is to provide a dual energy source electric vehicle energy management system based on predictive control to solve the problem of unreasonable energy flow distribution, low utilization rate and inability to realize efficient energy control in existing dual energy source pure electric vehicles and management issues.

In order to achieve the above object, the utility model provides the following technical solutions: An energy management system for electric vehicles with dual energy sources based on predictive control, including power batteries and supercapacitors, and also includes an energy predictive control module and an energy bidirectional supply module, the energy predictive control The module includes an information integration unit, an energy prediction area processing unit, a variable comparison unit, and a battery power distribution unit that are electrically connected in sequence. The bidirectional energy supply module includes a microprocessing control unit, a battery monitoring unit, a DC-DC bidirectional converter, and a capacitor control unit. The microprocessing control unit is electrically connected to the battery monitoring unit and the capacitor control unit respectively, the control signal of the battery monitoring unit is connected to the power battery, and the control signal of the capacitor control unit is connected to the supercapacitor and the DC-DC bidirectional converter.

The principle of this scheme is as follows: the information integration unit in the energy prediction control module is used to obtain the power output, battery SOC and super capacitor SOC status of the traction motor at the current moment; the energy prediction area processing unit is used to The input information in the future moment, calculate the reachable area of the battery power distribution factor in the predicted area, and obtain the optimal control torque sequence in this area; the variable comparison unit is used to convert the first optimal control torque sequence The value is output as the control variable at the next moment, and is compared with the variable values output before and after to obtain the set variable value. Finally, the battery power distribution unit performs energy distribution at different stages. Through the energy prediction control module, the electric vehicle battery module performance can be fully utilized. In the bidirectional energy supply module, the charging and discharging of the power battery and the supercapacitor are controlled by the microprocessing control unit, the battery monitoring unit and the capacitor control unit. When the electric vehicle needs high power for starting and accelerating, the supercapacitor participates in the discharge. The power required by the motor, when the electric vehicle decelerates and brakes, the working state of the motor is converted into a generator, and the supercapacitor is charged through the DC-DC bidirectional converter to realize energy recovery and avoid excessive current in the circuit fluctuations. Through the energy prediction control module, the energy flow distribution in the dual energy source pure electric vehicle can be made more reasonable, and the energy bidirectional supply module can control the charging and discharging of the battery of the electric vehicle, and recover the kinetic energy of the electric vehicle, so that the energy utilization rate is higher. In this way, efficient energy control and management can be realized for dual energy source pure electric vehicles.

Preferably, the bidirectional DC-DC converter includes two power switch tubes and an inductor, one end of the inductor is connected to the connection point of the two power switch tubes, and the supercapacitor is charged through the DC-DC bidirectional converter to realize energy recovery, and also avoid excessive fluctuations in current in the circuit.

Preferably, the power battery and the supercapacitor are connected in series, and a power distribution circuit is connected in parallel on the series branch, and the power distribution circuit includes a transformer and a switch tube connected in series with the transformer. The management and control of charging and discharging can make the battery power of the vehicle be used reasonably, and improve the mileage and energy recovery efficiency.

Preferably, the power battery is a lead-acid battery, a lithium-ion battery or a nickel-hydrogen battery, which has wide applicability.

Preferably, the micro-processing control unit is electrically connected with a signal filter circuit, a photoelectric isolation device, and has stronger anti-interference ability.

Preferably, the power battery and the supercapacitor are a power battery pack and a supercapacitor pack, which are composed of multiple monomers connected in series and in parallel. The supercapacitor has high charge and discharge efficiency, and can balance the charge and discharge current of the power battery, so that The battery current is basically stable around the average value, reducing the number of power battery charging and improving battery life.

The utility model has the advantages that: the electric vehicle energy management system is an effective improvement of the pure electric vehicle energy management mode. Through the predictive pure electric vehicle energy prediction control module and the energy bidirectional supply module with recovery control function, the performance of the electric vehicle battery module can be fully utilized, the energy utilization rate of the vehicle can be fully exploited, the failure of the battery module can be reduced, and the battery module can be extended. Increase the service life of electric vehicles, increase the sense of safety in the use of electric vehicles, and improve the economic performance and acceleration performance of electric vehicles.

Description of drawings

Fig. 1 is the structural block diagram of the embodiment of the dual-energy source electric vehicle energy management system based on predictive control of the present invention;

Fig. 2 is a schematic diagram of a power distribution circuit in an embodiment of the energy management system for an electric vehicle with dual energy sources based on predictive control of the present invention.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, the utility model is described in further detail:

As shown in Figure 1, the energy management system for electric vehicles with dual energy sources based on predictive control includes a lithium-ion battery pack and a supercapacitor pack, and also includes an energy predictive control module and an energy bidirectional supply module. The energy predictive control module includes sequentially connected Information integration unit, energy prediction area processing unit, variable comparison unit and battery power distribution unit, energy bidirectional supply module includes microprocessing control unit, battery monitoring unit, DC-DC bidirectional converter and capacitor control unit, bidirectional DC-DC converter It includes two power switch tubes and an inductor. One end of the inductor is connected to the connection point of the two power switch tubes. The micro-processing control unit is electrically connected to the battery monitoring unit and the capacitor control unit respectively. The control signal of the battery monitoring unit is connected to the lithium ion battery. The control signals of the battery pack and the capacitor control unit are connected to the super capacitor pack and the DC-DC bidirectional converter, and the micro-processing control unit is electrically connected to a signal filter circuit and a photoelectric isolation device.

As shown in Fig. 2, the lithium-ion battery pack and the supercapacitor pack are connected in series, and a power distribution circuit is connected in parallel on the series branch, and the power distribution circuit includes a transformer and a switch tube connected in series with the transformer.

Microprocessor control unit in the present embodiment adopts microprocessor ARM STM32F107, utilizes OSII system to do the operating system platform of microprocessor control unit, is used for facilitating system management and multitasking processing; Energy prediction area processing unit adopts microprocessor ARM STM32F103 , the information integration unit includes the DJS-1 speed sensor installed on the motor, the digital sensor MS5534CM installed on the storage battery and the supercapacitor bank, and the signal receiver SDTX/GSM980 on the information integration unit; the variable comparison unit adopts the numerical value Comparator NXP 74HCT688D; battery power distribution unit uses Narda power divider 4311B-2.

In this embodiment, the DJS-1 speed sensor in the energy prediction control module is used to sense the power output of the traction motor at the current moment, and transmit the signal to the signal receiver SDTX/GSM980, the digital sensor MS5534CM and the signal receiver SDTX/ GSM980 is used to obtain the state of battery SOC and supercapacitor pack S0C; microprocessor ARM STM32F103 determines the reachable area of the battery power distribution factor according to the current system state at time K, and calculates the optimal power according to the average value in the reachable area Distributed control torque sequence; the numerical comparator NXP 74HCT688D is used to output the first value of the control torque sequence of optimal power distribution as the control variable at the next moment, and output it with the variable output at K time and K+1 time Values are compared to get the set variable values, and finally the Narda power divider 4311B-2 performs energy distribution at different stages, and through the energy prediction control module, the performance of the electric vehicle battery module can be fully utilized. In the energy bidirectional supply module, the charging and discharging of the lithium-ion battery pack and the super capacitor pack are controlled through the microprocessor ARM STM32F107, the battery monitoring unit and the capacitor control unit. When the electric vehicle starts and accelerates and needs high power, the super capacitor pack Participate in the discharge and supplement the power required by part of the motor. When the electric vehicle decelerates and brakes, the working state of the motor is converted into a generator, and the DC-DC bidirectional converter is used to charge the supercapacitor bank to realize energy recovery and avoid Excessive fluctuations in current in the circuit. Through the energy prediction control module, the energy flow distribution in the dual energy source pure electric vehicle can be made more reasonable, and the energy bidirectional supply module can control the charging and discharging of the battery of the electric vehicle, and recover the kinetic energy of the electric vehicle, so that the energy utilization rate is higher. In this way, efficient energy control and management can be realized for dual energy source pure electric vehicles.

What is described above is only the preferred embodiment of the present utility model. It should be pointed out that for those skilled in the art, some deformations and improvements can be made without departing from the structure of the present utility model. These should also be regarded as The protection scope of the utility model, these all can not affect the effect that the utility model implements and the practicability of the patent.

Claims (6)

1. based on the dual energy source electric car energy management system of predictive control, comprise electrokinetic cell and super capacitor, it is characterized in that, also comprise energy predicting control module and the two-way supplying module of energy, described energy predicting control module comprises the information integerated unit that electricity successively connects, energy predicting regional processing unit, variable contrast unit and power of battery allocation units, the two-way supplying module of energy comprises micro-processing and control element (PCE), battery monitoring unit, DC-DC reversible transducer and Capacity control unit, micro-processing and control element (PCE) connects with battery monitoring unit and Capacity control unit electricity respectively, the control signal of battery monitoring unit connects electrokinetic cell, the control signal of Capacity control unit connects super capacitor and DC-DC reversible transducer.

2. as claimed in claim 1 based on the dual energy source electric car energy management system of predictive control, it is characterized in that, described DC-DC reversible transducer comprises two power switch pipes and an inductance, and one end of inductance is connected on the point of connection of two power switch pipes.

3. as claimed in claim 1 or 2 based on the dual energy source electric car energy management system of predictive control, it is characterized in that, described electrokinetic cell and super capacitor series connection, series arm is parallel with power distributing circuit, and this power distributing circuit comprises a voltage transformer and the switching valve with transformer series.

4., as claimed in claim 1 or 2 based on the dual energy source electric car energy management system of predictive control, it is characterized in that, described electrokinetic cell is lead-acid storage battery, lithium ion battery or nickel-hydrogen accumulator.

5., as claimed in claim 4 based on the dual energy source electric car energy management system of predictive control, it is characterized in that, described micro-processing and control element (PCE) electricity is connected to signal filter circuit, photoelectric isolating device.

6. as claimed in claim 5 based on the dual energy source electric car energy management system of predictive control, it is characterized in that, described electrokinetic cell and super capacitor are power battery pack and super capacitor group, are made up of through series connection and parallel combination multiple monomer.