CN104590036A - Efficient braking recycle method for electric-electric hybrid power system - Google Patents

Abstract

The invention provides an efficient braking recycle method for an electric-electric hybrid power system. The method includes the following steps of monitoring the speed of a whole vehicle and the voltage of a super capacitor in real time, calculating the kinetic energy E[p] of the whole vehicle and the energy E[c] capable of being absorbed by the super capacitor in real time, and controlling a DC/DC inverter to start at the optimal inversion conversion power P[o] when a braking signal is collected and E[c] is smaller than the product of E[p] and xi. The method is mainly for the optimization algorithm of the electric braking recycle of the hybrid power system of batteries and capacitors, it can be ensured that the kinetic energy of the whole vehicle is absorbed to the maximum degree, it can be ensured that the braking process of the whole vehicle is smooth as well, the braking comfort is high, and overcharge can not happen to super capacitors.

Description

A kind of efficient braking recovery method of electric electric mixed dynamic system

Technical field

The present invention relates to electric vehicle engineering field, specifically a kind of efficient braking recovery method of electric electric mixed dynamic system.

Background technology

Along with improving constantly of people's environmental consciousness, the quantity discharged reducing city automobile tail gas is the most important thing.Various new-energy automobile is put in the middle of the life of people, and the electronlmobil of the wherein high and low carbocyclic ring guarantor of energy efficiency, zero-emission becomes the main force of city new forms of energy traffic automobile.Based on the massive store characteristic of battery and the high rate charge-discharge characteristic of electric capacity, the hybrid electric vehicle of battery, capacitor combination becomes the preferred option of economizer system.But it is little that the behind of electric capacity high rate charge-discharge but conceals its capacity, braking removal process is easily full of the problem causing stopping without electricity.

At present, the solution on market mainly contains: (1) reduces B.P. in advance; (2) electric capacity is full of rear cancellation electric braking.The braking procedure of the first scheme is smoother, but but because B.P. is very little, most kinetic energy is stopped by gas and is transformed into heat loss; Although the braking procedure electric capacity of first scheme is filled with, whole kinetic energy can not be absorbed when high speed, and there will be the situation that electric braking suddenly disappears, impact braking traveling comfort.

Summary of the invention

The object of the present invention is to provide a kind of efficient braking recovery method of electric electric mixed dynamic system, the maximization electric braking that can realize kinetic energy in braking procedure reclaims, and can ensure to brake traveling comfort, for the Energy Conservation of electric electric mixed dynamic system is for good technical foundation.

Technical scheme of the present invention is:

An efficient braking recovery method for electric electric mixed dynamic system, comprises the following steps:

(1) entire car controller is from powering on beginning, in real time the monitoring velocity magnitude v of car load and the voltage U of ultracapacitor _c0;

(2) adopt following formula, calculate the kinetic energy E of car load in real time _pwith the ENERGY E that ultracapacitor can absorb _c:

$E_p=\frac{1}{2}*m*v^2$

$E_c=\frac{1}{2}*C*(U_{c\max }^2-U_{c0}^2)$

Wherein, m represents the real-time quality of car load, and C represents the electric capacity of ultracapacitor, U _cmaxwhat represent ultracapacitor is full of voltage;

(3) when collecting speed-slackening signal, and E _c< E _p*, during ζ, control DC/DC inverter is with best inversion transfer power P ₀start, wherein, ζ represents the maximum convesion factor of electric braking, best inversion transfer power P ₀following formulae discovery is adopted to obtain:

$P_0=\frac{M_{\max }*V_{\max }^2}{2*T_0}$

$T_0=\sqrt{\frac{v_0}{j_{\max }}}$

Wherein, M _maxrepresent the car load biggest quality, V _maxrepresent car load Maximum speed limit, T ₀represent the average braking time of car load, v ₀represent the velocity magnitude of car load in braking start time, j _max=0.36m/s ³, represent the size of the maximum acceleration of the comfortable braking of car load.

The present invention mainly for the optimized algorithm that the electric braking of the hybrid power system of battery, capacitor combination reclaims, can either ensure the maximum absorption of car load kinetic energy, and also can ensure that car load braking procedure is level and smooth, braking traveling comfort is good, and ultracapacitor can not overcharge.

Accompanying drawing explanation

Fig. 1 is the method flow diagram of invention.

Detailed description of the invention

Below, the present invention is further illustrated with specific embodiment by reference to the accompanying drawings.

As shown in Figure 1, a kind of efficient braking recovery method of electric electric mixed dynamic system, comprises the following steps:

S1, entire car controller, from powering on beginning, are monitored the velocity magnitude of car load in real time, and are calculated the real-time kinetic energy of car load:

$E_p=\frac{1}{2}*m*v^2$

Wherein, E _prepresent the real-time kinetic energy of car load, m represents the real-time quality of car load, and v represents the real-time speed size of car load;

S2, entire car controller, to power on beginnings, monitor the voltage of car load ultracapacitor in real time, and are full of voltage according to car load ultracapacitor, calculate the energy that car load ultracapacitor can absorb in real time:

$E_c=\frac{1}{2}*C*(U_{c\max }^2-U_{c0}^2)$

Wherein, E _crepresent the energy that car load ultracapacitor can absorb in real time, C represents the electric capacity of car load ultracapacitor, U _cmaxwhat represent car load ultracapacitor is full of voltage, U _c0represent the real-time voltage of car load ultracapacitor;

S3, when entire car controller collects braking requirement, first to E _cand E _pcompare, rule of thumb known, work as E _c>=E _p*, during ζ, represent that car load ultracapacitor can absorb current kinetic energy completely and not be filled, otherwise, work as E _c< E _p*, during ζ, represent that car load ultracapacitor can not absorb current kinetic energy completely, if be left intact, car load ultracapacitor can be filled, and causes the problem losing electric braking; Wherein, ζ represents the maximum convesion factor of electric braking, and size is about 0.66;

S4, find that current kinetic energy is comparatively large, E when entire car controller _c< E _p* during ζ, start DC/DC inverter, the energy of car load ultracapacitor is transferred to car load power battery pack with best inversion transfer power, to reach the object absorbing car load kinetic energy completely, wherein, best inversion transfer power adopts following formulae discovery:

$P_0=\frac{M_{\max }*V_{\max }^2}{2*T_0}$

$T_0=\sqrt{\frac{v_0}{j_{\max }}}$

Wherein, P ₀represent the best inversion transfer power of DC/DC inverter, M _maxrepresent the car load biggest quality, V _maxrepresent car load Maximum speed limit, T ₀represent the average braking time of car load, v ₀represent the velocity magnitude of car load in braking start time, j _max=0.36m/s ³, represent the size of the maximum acceleration of the comfortable braking of car load, according to v ₀and j _maxthe T calculated ₀be the minimum braking time of the comfortable braking of car load, thus farthest can guarantee car load braking traveling comfort.

The above embodiment is only be described the preferred embodiment of the present invention; not scope of the present invention is limited; under not departing from the present invention and designing the prerequisite of spirit; the various distortion that those of ordinary skill in the art make technical scheme of the present invention and improvement, all should fall in protection domain that claims of the present invention determine.

Claims (1)

1. an efficient braking recovery method for electric electric mixed dynamic system, is characterized in that, comprise the following steps:

(1) entire car controller is from powering on beginning, in real time the monitoring velocity magnitude v of car load and the voltage U of ultracapacitor _c0;

(2) adopt following formula, calculate the kinetic energy E of car load in real time _pwith the ENERGY E that ultracapacitor can absorb _c:

$E_p=\frac{1}{2}*m*v^2$

$E_c=\frac{1}{2}*C*(U_{c\max }^2-U_{c0}^2)$

Wherein, m represents the real-time quality of car load, and C represents the electric capacity of ultracapacitor, U _cmaxwhat represent ultracapacitor is full of voltage;

(3) when collecting speed-slackening signal, and E _c< E _p*, during ζ, control DC/DC inverter is with best inversion transfer power P ₀start, wherein, ζ represents the maximum convesion factor of electric braking, best inversion transfer power P ₀following formulae discovery is adopted to obtain:

$P_0=\frac{M_{\max }*V_{\max }^2}{2*T_0}$

$T_0=\sqrt{\frac{v_0}{j_{\max }}}$

Wherein, M _maxrepresent the car load biggest quality, V _maxrepresent car load Maximum speed limit, T _orepresent the average braking time of car load, v ₀represent the velocity magnitude of car load in braking start time, j _max=0.36m/s ³, represent the size of the maximum acceleration of the comfortable braking of car load.