CN202230137U - Power cell insulation detection system for electric automobile - Google Patents

Abstract

The present utility model provides a power cell insulation detection system for an electric automobile, and the system can be used for detecting insulation resistances of high voltage positive and negative poles of a power storage battery on an automobile body respectively. The system is suitable for a new energy automobile high voltage insulation detection device. The device comprises a high voltage subsystem, an AD sampling subsystem, an isolation subsystem, a communication subsystem, and a fault alarming subsystem. In the insulation detection system, different resistors are respectively merged into the positive and negative ends of the power battery, the insulation resistor resistance is calculated through collecting voltage before and after the resistors are merged, the resistance can be output to a whole automobile controller through a communication module, real-time monitoring of the operation state of an electric automobile high voltage circuit can be realized, and safety of people and automobiles can be guaranteed.

Description

A kind of used for electric vehicle electrokinetic cell insulation detection system

Technical field

The utility model relates to the battery management system in electric automobile field, a kind of specifically HVDC electrical isolation detection system.

Background technology

Electric automobile is the electromechanical assembly of a complicacy, and the electric automobile condition of work is more abominable, and the rapid variation of vibration, temperature and humidity all might cause the aging rapidly even damage in insulation of power cable and other insulating material, and apparatus insulated performance is descended.This not only can influence the normal control of vehicle, goes back the entail dangers to personal safety.Therefore, measure the insulating property between high-voltage electrical apparatus and the vehicle body accurately, in real time, significant to guaranteeing passenger and vehicle safety, electrical equipment operate as normal.

Existing insulation detection technique is just carried out qualitative detection to battery high-pressure system state of insulation, infers its electric leakage state, can not accurately judge the electric leakage degree; And the positive pole that the insulation detection system among this paper can accurately calculate high-pressure system is to vehicle body ground, the negative pole insulation resistance value accurately to vehicle body ground, thereby the real-time running state of electric motor car high-tension circuit is monitored, and ensured travel safety.

The utility model content

The purpose of the utility model is to provide a kind of used for electric vehicle electrokinetic cell insulation detection system.Through this system not only can accurate Calculation high pressure both positive and negative polarity to the insulating resistance value on vehicle body ground, can pass through communication system simultaneously, in real time insulation resistance value is monitored and fault alarm.

In order to realize the purpose of the utility model, the used for electric vehicle electrokinetic cell insulation detection system that the utility model proposes,

A kind of used for electric vehicle electrokinetic cell insulation detection system; Be to be used to detect the Circuits System of electric automobile high-tension battery bag 10 high pressure both positive and negative polarities, comprise high pressure sub-system, AD sampled subsystem, separaant system, communication subsystem the insulation resistance value of vehicle body ground (GND).Said insulation detection system high-pressure section is made up of power brick (10), and the battery module that this power brick is made up of several cell SP is formed; This power brick two ends connect insulation testing circuit, and this insulation testing circuit comprises and is connected the anodal equivalent insulation resistance R of power brick 10 positive poles to vehicle body ground (GND) _pBe connected in parallel on this positive pole equivalence insulation resistance R _pThe anodal auxiliary resistance R at two ends _K1, and at the negative pole equivalence insulation resistance R of power brick (10) negative pole to vehicle body ground (GND) _nBe connected in parallel on this negative pole equivalence insulation resistance R _nThe negative pole auxiliary resistance R at two ends _K2, and control anodal auxiliary resistance R respectively _K1, negative pole auxiliary resistance R _K2The anodal CS K of place in circuit ₁, negative pole CS K ₂The AD sampled subsystem is measured the voltage of said power brick both positive and negative polarity and is outputed to whole-control system through said communication subsystem and separaant system.

As the further characteristic of the utility model, said AD sampled subsystem comprises calculus of differences circuit and AD sample circuit.

Further characteristic as the utility model also comprises an error alarm subsystem, and it is connected with said entire car controller.

Owing to adopt above technical scheme; The used for electric vehicle electrokinetic cell of the utility model insulation detection system the electrokinetic cell anode over the ground, negative terminal incorporates different resistance over the ground respectively into; The voltage of incorporating the resistance front and back through collection into calculates the insulation resistance resistance; Export entire car controller to through communication module, the running status of electric automobile high-tension circuit is monitored in real time, ensure safety of person vehicle.

Description of drawings

Fig. 1 is the used for electric vehicle insulation detection system structural drawing of the utility model.

Fig. 2-1 is the circuit diagram of the cathode voltage sampled subsystem of the utility model.

Fig. 2-2 is the circuit diagram of the cathode voltage sampled subsystem of the utility model.

Fig. 3 does not all incorporate the equivalent schematic diagram of auxiliary resistance into for the insulation testing circuit both positive and negative polarity that the utility model proposed.

Fig. 4 incorporates the equivalent schematic diagram of auxiliary resistance into for the insulation testing circuit positive pole that the utility model proposed.

Fig. 5 incorporates the equivalent schematic diagram of auxiliary resistance into for the insulation testing circuit negative pole that the utility model proposed.

Embodiment

Below in conjunction with accompanying drawing and embodiment, the utility model is described further.

In following accompanying drawing, 10 is the power accumulator bag, R _pBe the equivalent over the ground insulating resistance value of power accumulator positive pole, R _nBe power accumulator negative pole equivalent resistance over the ground, R _K1Be anodal auxiliary resistance, R _K2Be negative pole auxiliary resistance, K ₁Be anodal CS, K ₂Be negative pole CS, U _Pi, U _NiBe respectively first, second and tertiary voltage value (i=0,1,2) that positive and negative electrode resistance is divided.

Fig. 1 is the general structure block diagram of the used for electric vehicle electrokinetic cell insulation detection system of the utility model, and this system mainly is made up of five sub-systems: high pressure sub-system, AD sampled subsystem 11, separaant system, communication subsystem, error alarm subsystem.Said insulation detection system high-pressure section is made up of power brick, and the battery module that this power brick is made up of several cell SP is formed; This power brick two ends connect insulation testing circuit 12, and this insulation testing circuit 12 comprises and is connected power brick 10, the positive pole anodal equivalent insulation resistance R to vehicle body ground GND _pBe connected in parallel on this positive pole equivalence insulation resistance R _pThe anodal auxiliary resistance R at two ends _K1, and at the negative pole equivalence insulation resistance R of power brick 10 negative poles to vehicle body ground GND _nBe connected in parallel on this negative pole equivalence insulation resistance R _nThe negative pole auxiliary resistance R at two ends _K2, and control anodal auxiliary resistance R respectively _K1, negative pole auxiliary resistance R _K2The anodal CS K of place in circuit ₁, negative pole CS K ₂The AD sampled subsystem is measured the voltage of said power brick both positive and negative polarity and is outputed to entire car controller MCU through communication subsystem and separaant system.Its workflow is: as shown in Figure 3, measure the first magnitude of voltage U before both positive and negative polarity is incorporated resistance into respectively through the AD sampled subsystem _P0, U _N0, MCU judges both positive and negative polarity CS K according to recording magnitude of voltage ₁, K ₂Disconnection with closed, incorporate auxiliary resistance R into through the measurement of AD sampled subsystem again _K1Or R _K2After the second magnitude of voltage U _P1, U _N1Perhaps tertiary voltage value U _P2, U _N2,, just can accurately calculate R according to twice measurement result _p, R _nValue, export MCU to, judge by MCU to be uploaded to entire car controller to insulation resistance value simultaneously and make the whether judgement of fault alarm.

Communication separaant system among Fig. 1 is used for the isolation of electric automobile high tension loop and low-voltage control circuit, has ensured the security of system, has improved antijamming capability.

Fig. 2-1 is the detailed schematic diagram of anodal AD sampled subsystem; Fig. 2-2 is the detailed schematic diagram of negative pole AD sampled subsystem; Adopted the calculus of differences circuit as input in the native system, common mode input signal has been had very strong inhibition ability, can suppress to bring the influence of circuit by the variation of external condition; Like temperature noise etc., thereby improved the degree of accuracy of AD sampling.

The method that used for electric vehicle electrokinetic cell insulation detection system through the utility model realizes, it is applicable to and detects the method for electric automobile high-tension battery bag 10 high pressure both positive and negative polarities to the insulation resistance value of vehicle body ground GND, comprises as follows:

1) as shown in Figure 3, make CS K ₁, K ₂All break off, first voltage of measuring between positive and negative bus and the vehicle body ground GND is respectively U _P0, U _N0, can obtain formula [1] by circuital law

[1]

$\frac{U_{p0}}{R_p}=\frac{U_{n0}}{R_n}$

2) these two voltages are compared; If anodal first voltage U to vehicle body ground _P0=0, the error alarm subsystem positive pressure utmost point insulation fault of offering a high price is if negative pole is to first voltage U on vehicle body ground _N0=0, error alarm subsystem is offered a high price and is pressed the negative pole insulation fault;

3) if anodal first voltage U to vehicle body ground _P0＞=negative pole is to first voltage U on vehicle body ground _N0, as shown in Figure 4, anodal CS K ₁Closed, negative pole control K ₂Break off, then between positive bus-bar and vehicle body ground, add standard biasing resistor R _K1, second voltage of measuring between positive and negative bus and the vehicle body ground is respectively U _P1, U _N1, can obtain formula [2] equally

[2]

$\frac{U_{p1}}{\frac{R_p\×R_{k1}}{P_p+R_{k1}}}=\frac{U_{n1}}{R_n}$

4) if anodal first voltage U to vehicle body ground _P0＜negative pole is to first voltage U on vehicle body ground _N0, as shown in Figure 5, anodal CS K ₁Disconnection, negative pole control K ₂Closure then adds standard biasing resistor R between negative busbar and vehicle body ground _K2, the tertiary voltage of measuring between positive and negative bus and the vehicle body ground is respectively U _P2, U _N2, can obtain formula [3] equally

[3]

$\frac{U_{p2}}{R_p}=\frac{U_{n2}}{\frac{R_n\&times;R_{k2}}{R_n+{\mathrm{<figure-callout\; id="2"\; label="R\; k"\; filenames="HDA0000099860230000012.png"\; state="\{\{state\}\}">R</figure-callout>}}_k}}$

5) judge by the MCU controller, work as U _P0More than or equal to U _N0, get formula [4] by formula [1], [2].

[4]

$\left\{\begin{array}{c}{R}_p=\frac{R_{k1}(U_{p0}\&times;U_{n1}-U_{p1}\&times;U_{n0})}{U_{n0}\&times;U_{p1}}\\ R_n=\frac{R_{k1}(U_{p0}\&times;U_{n1}-U_{p1}\&times;U_{n0})}{U_{p1}\&times;U_{p0}}\end{array}\right.$

6) judge by the MCU controller, work as U _P0Less than U _N0, get formula [5] by formula [1], [3].

[5]

$\left\{\begin{array}{c}{R}_p=\frac{R_{k2}({\mathrm{<figure-callout\; id="2"\; label="U\; p"\; filenames="HDA0000099860230000012.png"\; state="\{\{state\}\}">U</figure-callout>}}_p\&times;U_{n0}-U_{p0}\&times;U_{n2})}{U_{n0}\&times;U_{n2}}\\ R_n=\frac{R_{k2}({\mathrm{<figure-callout\; id="2"\; label="U\; p"\; filenames="HDA0000099860230000012.png"\; state="\{\{state\}\}">U</figure-callout>}}_p\&times;U_{n0}-U_{p0}\&times;U_{n2})}{U_{p0}\&times;{\mathrm{<figure-callout\; id="2"\; label="U\; n"\; filenames="HDA0000099860230000012.png"\; state="\{\{state\}\}">U</figure-callout>}}_n}\end{array}\right.$

7), just can accurately calculate power accumulator high pressure positive and negative terminal respectively to the insulation resistance value R of vehicle body ground GND according to formula [4] or formula [5] _p, R _n

According to the requirement of system, to the insulation resistance value R that calculates to insulating property _p, R _nCarry out fault distinguishing, be uploaded to entire car controller through communication subsystem simultaneously.

But above-mentioned embodiment is exemplary, is to be the restriction that this patent is comprised scope in order better to make those skilled in the art can understand this patent, can not to be interpreted as; So long as according to spirit that this patent discloses done anyly be equal to change or modify, all fall into the scope that this patent comprises.

Claims (3)

1. used for electric vehicle electrokinetic cell insulation detection system; Be to be used to detect the Circuits System of electric automobile high-tension battery bag (10) high pressure both positive and negative polarity to the insulation resistance value of vehicle body ground (GND); Comprise high pressure sub-system, AD sampled subsystem, separaant system, communication subsystem; It is characterized in that: said insulation detection system high-pressure section is made up of power brick (10), and the battery module that this power brick is made up of several cell SP is formed; This power brick two ends connect insulation testing circuit, and this insulation testing circuit comprises and is connected the anodal equivalent insulation resistance (R of power brick (10) positive pole to vehicle body ground (GND) _p) and be connected in parallel on this positive pole equivalence insulation resistance (R _p) the anodal auxiliary resistance (R at two ends _K1), and at the negative pole equivalence insulation resistance (R of power brick (10) negative pole to vehicle body ground (GND) _n) and be connected in parallel on this negative pole equivalence insulation resistance (R _n) the negative pole auxiliary resistance (R at two ends _K2), and control anodal auxiliary resistance (R respectively _K1), negative pole auxiliary resistance (R _K2) the anodal CS (K of place in circuit ₁), negative pole CS (K ₂); The AD sampled subsystem is measured the voltage of said power brick both positive and negative polarity and is outputed to entire car controller through said communication subsystem and separaant system.

2. used for electric vehicle electrokinetic cell insulation detection system according to claim 1, it is characterized in that: said AD sampled subsystem comprises calculus of differences circuit and AD sample circuit.

3. used for electric vehicle electrokinetic cell insulation detection system according to claim 1 and 2, it is characterized in that: also comprise an error alarm subsystem, it is connected with said entire car controller.

Images