CN103439577A - Isolation resistance detection system and detection method of power battery of electric vehicle - Google Patents

Abstract

The invention discloses an isolation resistance detection system and a detection method of a power battery of an electric vehicle. The detection system comprises a micro controller, an isolation detection circuit, a filter circuit, an auxiliary high-voltage source, a temperature sensor, a humidity sensor, a phase inverter and a CAN communication circuit. The detection method includes the steps that whether the power battery is online or offline is judged, then the auxiliary high-voltage source is implanted into the isolation detection circuit, and the micro controller calculates and obtains the isolation resistance value of the positive pole and the isolation resistance value of the negative pole of the power battery according to the Ohm law. When in an online state or an offline state, the power battery can be detected, reliability of detection can be improved, and risks of damages caused by electric leakage are reduced.

Description

Insulation resistance detection system and the detection method of electric automobile power battery

Technical field

The invention belongs to the electric insulation detection technique field of electric automobile, be specifically related to a kind of insulation resistance detection system and detection method of electric automobile power battery.

Background technology

The energy of electric automobile is mainly derived from vehicle-mounted electrokinetic cell, due to the operating voltage higher (generally at 300V-700V) of electrokinetic cell, if the situation of the electric leakage that meets accident will directly threaten personal safety.Therefore, need to detect in real time the insulation resistance of electrokinetic cell, to understand the insulation status of electrokinetic cell.

Traditional power battery insulation resistance detection mode can only electrokinetic cell be in line states (be in high tension loop always just, after total negative relay closes, electrokinetic cell work) time, judge that whether current electrokinetic cell is in the electric leakage state, can not electrokinetic cell in off-line state (be in high tension loop always just, before total negative relay closes, electrokinetic cell is not worked) time detects, can not judge electrokinetic cell is anodal electric leakage or negative pole electric leakage or bipolar electric leakage simultaneously, just can not calculate electrokinetic cell, the insulating resistance value of negative pole (be electrokinetic cell just, negative pole insulation against ground resistance), the degree of accuracy detected is inadequate, reliability is low.

The patent that publication number is CN102298092A discloses a kind of power battery insulation resistance detection method and device of electric automobile, it can be when electrokinetic cell be in line states, in real time the insulation resistance between electrokinetic cell positive and negative busbar and bonding is detected, and can measure exactly the positive pole of electrokinetic cell, negative pole and the bipolar insulating resistance value to body earth (), but it can not be detected during in off-line state at electrokinetic cell, if there is the electric leakage situation in electrokinetic cell, in high tension loop always just, before total negative relay closes, can not detect, need to be by after its closure, just can detect electric leakage.In high tension loop, connect, electrokinetic cell is started working, and when the car load high pressure powers on, people are easy to because of electric leakage injured (be injured risk large), and this detection method and device are unfavorable for promoting in the electric automobile industry.

Summary of the invention

The insulation resistance detection system and the detection method that the purpose of this invention is to provide a kind of electric automobile power battery, at electrokinetic cell during in online or off-line state, all can the insulation resistance of electrokinetic cell be detected, improved the reliability detected, reduced because of the injured risk of electric leakage.

The insulation resistance detection system of electric automobile power battery of the present invention, comprise microcontroller, insulation detecting circuit, filtering circuit, auxiliary high-voltage power supply, temperature sensor, humidity sensor, phase inverter and CAN communicating circuit.Described microcontroller is connected with auxiliary high-voltage power supply, controls auxiliary high-voltage power supply work; Auxiliary high-voltage power supply is connected with the input end of insulation detecting circuit, and the outer low pressure direct current is converted to high voltage direct current, is input in insulation detecting circuit; Microcontroller is connected with the control end of insulation detecting circuit, controls the interior electronic switch closes of insulation detecting circuit/disconnection; Microcontroller is connected with the voltage output end of insulation detecting circuit by filtering circuit, under described electronic switch closes/disconnection different conditions, microcontroller gathers the output voltage of insulation detecting circuit, and the positive and negative electrode insulating resistance value that carries out the judgement of electrokinetic cell on-line/off-line state and electrokinetic cell calculates; Microcontroller is connected with temperature sensor, humidity sensor, obtains insulation detecting circuit temperature, moisture signal on every side, and proofreaies and correct the positive and negative electrode insulating resistance value of electrokinetic cell; Described microcontroller is connected with phase inverter, the positive and negative electrode insulating resistance value of the electrokinetic cell after calculating and proofreading and correct and predefined positive and negative electrode insulating resistance value are compared, whether whether judgement insulation qualified (reaching required value), and export corresponding logic level; Microcontroller is connected with the CAN communicating circuit, by temperature, humidity, calculating and the positive and negative electrode insulating resistance value of the electrokinetic cell after proofreading and correct and insulation whether qualified signal sends on the CAN bus.

Insulation detecting circuit is just characterizing electrokinetic cell for exporting, negative pole insulating resistance value electric signal, filtering circuit carries out filtering for the voltage to insulation detecting circuit output, improve the accuracy of detection signal and the immunity to interference of system, auxiliary high-voltage power supply boosts to the high voltage direct current of the required approximately 700V of insulation detecting circuit for the 10～15V low-voltage DC by the outside input, temperature sensor is for detection of the temperature around insulation detecting circuit, humidity sensor is for detection of the humidity around insulation detecting circuit, microcontroller can be the single-chip microcomputer that possesses analog-digital conversion function, the CAN communicating circuit is responsible for microcontroller and outside CAN equipment carries out communication, can receive external command and revise inner parameter, the information detected can be sent on the CAN bus again, the logic level whether phase inverter will insulate qualified is anti-phase, improve external driving force.

Preferably, described insulation detecting circuit consists of first, second, third, fourth electronic switch and first, second, third, fourth, the 5th, the 6th resistance.One end of the first electronic switch connects the positive pole of electrokinetic cell by total positive relay, one end of one end of another termination the first resistance, the 4th resistance and the negative pole of auxiliary high-voltage power supply, one end of another termination the second resistance of the first resistance, the other end ground connection of the second resistance, one end of another termination the 5th resistance of the 4th resistance, the other end ground connection of the 5th resistance; One end ground connection of the 3rd resistance, one end of another termination the 6th resistance, one end of another termination the second electronic switch of the 6th resistance and an end of quadrielectron switch, the other end of the second electronic switch connects the negative pole of electrokinetic cell, the positive pole of the auxiliary high-voltage power supply of another termination of quadrielectron switch by total negative relay; One termination the first resistance of the 3rd electronic switch and the tie point of the second resistance, the positive pole of the auxiliary high-voltage power supply of another termination of the 3rd electronic switch; The control termination microcontroller of first, second, third, fourth electronic switch, the closure of reception microcontroller/disconnection is controlled; Second, third, the voltage output end of the 5th resistance connects microcontroller by filtering circuit, microcontroller gathers second, third, the 5th ohmically voltage is calculated.

The method that adopts the insulation resistance detection system of above-mentioned electric automobile power battery to be detected comprises:

Step 1: temperature, moisture signal around the insulation detecting circuit that microcontroller Real-time Obtaining temperature sensor and humidity sensor transmit;

Step 2: the auxiliary high-voltage power supply of microprocessor controls is not worked, portions of electronics switch closure, the portions of electronics switch controlled in insulation detecting circuit disconnect, collection is through the output voltage of filtered insulation detecting circuit, with predetermined threshold value, compare, the judgement electrokinetic cell is in online or off-line state;

Step 3: if electrokinetic cell is in line states, the auxiliary high-voltage power supply work of microprocessor controls, high voltage direct current is introduced to insulation detecting circuit, portions of electronics switch in the microprocessor controls insulation detecting circuit is closed, the portions of electronics switch disconnects, collection is through the output voltage of filtered insulation detecting circuit, calculate the positive and negative electrode insulating resistance value of electrokinetic cell, utilize the positive and negative electrode insulating resistance value of the electrokinetic cell after described temperature, moisture signal correction calculation;

Step 4: if electrokinetic cell is in off-line state, the auxiliary high-voltage power supply work of microprocessor controls, high voltage direct current is introduced to insulation detecting circuit, portions of electronics switch in the microprocessor controls insulation detecting circuit is closed, the portions of electronics switch disconnects, collection is through the output voltage of filtered insulation detecting circuit, calculate the positive and negative electrode insulating resistance value of electrokinetic cell, utilize the positive and negative electrode insulating resistance value of the electrokinetic cell after described temperature, moisture signal correction calculation;

Step 5: positive and negative electrode insulating resistance value and the predefined positive and negative electrode insulating resistance value of the electrokinetic cell after proofreading and correct in step 3 or step 4 are compared, and whether the judgement insulation is qualified; By insulation, whether qualified logic level is exported by phase inverter; By the temperature in electrokinetic cell, humidity, whether qualified signal sends on the CAN bus for the positive and negative electrode insulating resistance value of the electrokinetic cell after correction and insulation.

Preferably, in step 2, first, second electronic switch closes in the microprocessor controls insulation detecting circuit, the 3rd, quadrielectron switch disconnects, and gathers the second ohmically voltage V2 of insulation detecting circuit, with predetermined threshold value V ^*compare, if V2 is more than or equal to V ^*, electrokinetic cell is in line states, if V2 is less than V ^*, electrokinetic cell is in off-line state.

In step 3, microcontroller is first controlled first, second electronic switch closes in insulation detecting circuit, three, quadrielectron switch disconnects, and gathers the second ohmically voltage V2, the 3rd ohmically voltage V3, the 5th ohmically voltage V5 the storage of insulation detecting circuit; Then, described the first, the 3rd electronic switch closes of microprocessor controls, second, quadrielectron switch disconnects, and gathers the described second ohmically voltage V2 ', the 5th ohmically voltage V5 ' storage; Microcontroller is according to formula

calculate anodal insulating resistance value (the being anodal insulation against ground resistance value) R of electrokinetic cell _p; Microcontroller is according to formula $R_n=\frac{R3+R6}{R3}*\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">V</figure-callout>}3/(\frac{R4+R5}{\mathrm{<figure-callout\; id="5"\; label="R"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">R</figure-callout>}5}*\frac{V5}{R_p}+\frac{V5}{\mathrm{<figure-callout\; id="5"\; label="R"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">R</figure-callout>}5}+\frac{V2}{R2}-\frac{V3}{R3}),$ Calculate negative pole insulating resistance value (the being negative pole insulation against ground resistance value) R of electrokinetic cell _n.

In step 4, microcontroller is first controlled the first, the 3rd electronic switch closes in insulation detecting circuit, and second, quadrielectron switch disconnects, gather the second ohmically voltage V2 ", the 5th ohmically voltage V5 " the storage of insulation detecting circuit; Then, microprocessor controls described first, second, quadrielectron switch closure, " ' and storage that the 3rd electronic switch disconnects, and gathers the described second ohmically voltage V2 " ', the 3rd ohmically voltage V3 " ', the 5th ohmically voltage V5; Microcontroller is according to formula

calculate the anodal insulating resistance value R of electrokinetic cell _p; Microcontroller is according to formula $R_n=\frac{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">R</figure-callout>}3+R6}{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">R</figure-callout>}3}*{\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">V</figure-callout>}3}^{\&prime;\&prime;\&prime;}/(\frac{\mathrm{<figure-callout\; id="4"\; label="R"\; filenames="HDA00003657206000011.png,HDA00003657206000012.png"\; state="\{\{state\}\}">R</figure-callout>}4+R5}{\mathrm{<figure-callout\; id="5"\; label="R"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">R</figure-callout>}5}*\frac{{\mathrm{<figure-callout\; id="5"\; label="V"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">V</figure-callout>}5}^{\&prime;\&prime;\&prime;}}{R_p}+\frac{{\mathrm{<figure-callout\; id="5"\; label="V"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">V</figure-callout>}5}^{\&prime;\&prime;\&prime;}}{\mathrm{<figure-callout\; id="5"\; label="R"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">R</figure-callout>}5}+\frac{{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HDA00003657206000011.png,HDA00003657206000012.png"\; state="\{\{state\}\}">V</figure-callout>}2}^{\&prime;\&prime;\&prime;}}{R2}-\frac{{\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">V</figure-callout>}3}^{\&prime;\&prime;\&prime;}}{R3}),$ Calculate the negative pole insulating resistance value R of electrokinetic cell _n.

Owing to adopting technique scheme, the present invention can not only measure exactly positive pole, the negative pole insulating resistance value of electrokinetic cell when electrokinetic cell is in line states, and can measure exactly positive pole, the negative pole insulating resistance value of electrokinetic cell during in off-line state at electrokinetic cell, the reliability of detection is high.If electrokinetic cell electric leakage, in the situation that in high tension loop total just, always negative relay is not closed, just can detect, avoided in the case, high tension loop is connected and caused people injured because of electric leakage, reduced injured risk, safe, be conducive to promote in the electric automobile industry.

The accompanying drawing explanation

The circuit block diagram that Fig. 1 is medium power battery insulation resistance detection system of the present invention.

The schematic diagram that Fig. 2 is insulation detecting circuit in the present invention.

The first working state figure (electrokinetic cell is in line states) that Fig. 3 is insulation detecting circuit in the present invention.

The second working state figure (electrokinetic cell is in line states) that Fig. 4 is insulation detecting circuit in the present invention.

The third working state figure (electrokinetic cell is in off-line state) that Fig. 5 is insulation detecting circuit in the present invention.

The 4th kind of working state figure (electrokinetic cell is in off-line state) that Fig. 6 is insulation detecting circuit in the present invention.

The process flow diagram that Fig. 7 is medium power battery insulation resistance detection method of the present invention.

Embodiment

Below in conjunction with accompanying drawing, the invention will be further described.

The insulation resistance detection system of electric automobile power battery as shown in Figure 1 and Figure 2, comprise microcontroller 1, insulation detecting circuit 2, filtering circuit 3, auxiliary high-voltage power supply 4, temperature sensor 5, humidity sensor 6, phase inverter 7 and CAN communicating circuit 8, microcontroller 1 adopts the single-chip microcomputer that possesses the AD translation function, and auxiliary high-voltage power supply 4 can boost to 10～15V low-voltage DC of outside input the high voltage direct current of about 700V.Microcontroller 1 is connected with auxiliary high-voltage power supply 4, controls auxiliary high-voltage power supply work.Insulation detecting circuit 2 consists of the first electronic switch S1, the second electronic switch S2, the 3rd electronic switch S3, quadrielectron switch S 4 and the first resistance R 1, the second resistance R 2, the 3rd resistance R 3, the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6; The end of the first electronic switch S1 connects the positive pole of electrokinetic cell by total positive relay K 1, the negative pole (being the Ex_HV-pin) of one end of another termination the first resistance R 1, an end of the 4th resistance R 4 and auxiliary high-voltage power supply 4, one end of another termination the second resistance R 2 of the first resistance R 1, the other end ground connection of the second resistance R 2, one end of another termination the 5th resistance R 5 of the 4th resistance R 4, the other end ground connection of the 5th resistance R 5; One end ground connection of the 3rd resistance R 3, one end of another termination the 6th resistance R 6, the end of another termination second electronic switch S2 of the 6th resistance R 6 and an end of quadrielectron switch S 4, the other end of the second electronic switch S2 connects the negative pole of electrokinetic cell, the positive pole (being the Ex_HV+ pin) of the auxiliary high-voltage power supply 4 of another termination of quadrielectron switch S 4 by total negative relay K 2; Termination first resistance R 1 of the 3rd electronic switch S3 and the tie point of the second resistance R 2, the positive pole of the auxiliary high-voltage power supply 4 of another termination of the 3rd electronic switch S3; The control end of the first electronic switch S1, the second electronic switch S2, the 3rd electronic switch S3, quadrielectron switch S 4 all connects microcontroller 1, and the closure of reception microcontroller/disconnection is controlled; The voltage output end of the second resistance R 2, the 3rd resistance R 3, the 5th resistance R 5 connects respectively three AD interfaces of microcontroller 1 by filtering circuit 3, the voltage that microcontroller gathers on the second resistance R 2, the 3rd resistance R 3, the 5th resistance R 5 carries out the positive and negative electrode insulating resistance value calculating of the judgement of electrokinetic cell on-line/off-line state and electrokinetic cell.Two other AD interface of microcontroller 1 is connected with temperature sensor 5, humidity sensor 6 respectively, obtains insulation detecting circuit temperature, moisture signal on every side, and the positive and negative electrode insulating resistance value of the electrokinetic cell after correction calculation.Microcontroller 1 is connected with phase inverter 7; the positive and negative electrode insulating resistance value of the electrokinetic cell after calculating and proofreading and correct and predefined positive and negative electrode insulating resistance value are compared; whether the judgement insulation is qualified; and export corresponding logic level; defective if insulate (having fault); microcontroller 1 will be exported a logic low; this logic low is exported high level to external unit after phase inverter is reverse; this logical signal can be used for the quick protection of relay and turn-offs, and also can be used for host computer to insulation fault state interrupt signal.Microcontroller 1 is connected with CAN communicating circuit 8, by temperature, humidity, calculating and the positive and negative electrode insulating resistance value of the electrokinetic cell after proofreading and correct and insulation whether qualified signal sends on the CAN bus.

As shown in Fig. 3 to Fig. 7, the method that adopts the insulation resistance detection system of above-mentioned electric automobile power battery to carry out the detection of power battery insulation resistance value comprises:

Step 1: temperature, moisture signal around the insulation detecting circuit that microcontroller 1 Real-time Obtaining temperature sensor 5 and humidity sensor 6 transmit.

Step 2: microcontroller 1 is controlled auxiliary high-voltage power supply 4 and is not worked, the first electronic switch S1, the second electronic switch S2 closure that microcontroller 1 is controlled in insulation detecting circuit 2, the 3rd electronic switch S3, quadrielectron switch S 4 disconnect, voltage V2 on the second resistance R 2 of microcontroller 1 collection insulation detecting circuit 2, with predetermined threshold value V ^*compare, if V2 is more than or equal to V ^*, electrokinetic cell is in line states (be total positive relay K 1 in high tension loop, always negative relay K 2 closures), if V2 is less than V ^*, electrokinetic cell is in off-line state (being total positive relay K 1, always negative relay K 2 disconnections in high tension loop).

Step 3: if electrokinetic cell is in line states, at first, microcontroller 1 is controlled auxiliary high-voltage power supply 4 work; Secondly, the first electronic switch S1, the second electronic switch S2 closure that microcontroller 1 is controlled in insulation detecting circuit 2, the 3rd electronic switch S3, quadrielectron switch S 4 disconnect, the voltage V2 on the second resistance R 2 of collection insulation detecting circuit 2, the voltage V3 on the 3rd resistance R 3, the voltage V5 on the 5th resistance R 5 storage; Again, microcontroller 1 is controlled the first electronic switch S1, the 3rd electronic switch S3 closure, the second electronic switch S2, quadrielectron switch S 4 disconnect, the high voltage direct current of about 700V is introduced to insulation detecting circuit 2, gather the voltage V2 ' on the second resistance R 2, the voltage V5 ' on the 5th resistance R 5 storage; Then, according to formula

calculate the anodal insulating resistance value R of electrokinetic cell _p, according to formula $R_n=\frac{R3+R6}{R3}*\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">V</figure-callout>}3/(\frac{R4+R5}{R5}*\frac{V5}{R_p}+\frac{V5}{R5}+\frac{V2}{R2}-\frac{V3}{R3}),$ Calculate the negative pole insulating resistance value R of electrokinetic cell _n; Finally, microcontroller 1 utilizes the temperature obtained in step 1, the positive and negative electrode insulating resistance value R of the electrokinetic cell after the moisture signal correction calculation _p, R _n.

Step 4: if electrokinetic cell in off-line state, at first, microcontroller 1 is controlled auxiliary high-voltage power supply 4 work; Secondly, the first electronic switch S1, the 3rd electronic switch S3 closure that microcontroller 1 is controlled in insulation detecting circuit 2, the second electronic switch S2, quadrielectron switch S 4 disconnect, the high voltage direct current of about 700V is introduced to insulation detecting circuit 2, gather voltage V2 on the second resistance R 2 of insulation detecting circuit 2 ", the 5th resistance R 5 on voltage V5 " storage; Again, microcontroller 1 is controlled the first electronic switch S1, the second electronic switch S2, quadrielectron switch S 4 closures, the 3rd electronic switch S3 disconnects, the high voltage direct current of about 700V is introduced to insulation detecting circuit 2, gathers the voltage V5 on voltage V2 on the second resistance R 2 " ', the voltage V3 on the 3rd resistance R 3 " ', the 5th resistance R 5 " ' and storage; Then, microcontroller 1 is according to formula

calculate the anodal insulating resistance value R of electrokinetic cell _p, according to formula $R_n=\frac{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">R</figure-callout>}3+R6}{\mathrm{<figure-callout\; id="3"\; label="R"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">R</figure-callout>}3}*{\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">V</figure-callout>}3}^{\&prime;\&prime;\&prime;}/(\frac{\mathrm{<figure-callout\; id="4"\; label="R"\; filenames="HDA00003657206000011.png,HDA00003657206000012.png"\; state="\{\{state\}\}">R</figure-callout>}4+R5}{\mathrm{<figure-callout\; id="5"\; label="R"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">R</figure-callout>}5}*\frac{{\mathrm{<figure-callout\; id="5"\; label="V"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">V</figure-callout>}5}^{\&prime;\&prime;\&prime;}}{R_p}+\frac{{\mathrm{<figure-callout\; id="5"\; label="V"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">V</figure-callout>}5}^{\&prime;\&prime;\&prime;}}{\mathrm{<figure-callout\; id="5"\; label="R"\; filenames="HDA00003657206000011.png"\; state="\{\{state\}\}">R</figure-callout>}5}+\frac{{\mathrm{<figure-callout\; id="2"\; label="V"\; filenames="HDA00003657206000011.png,HDA00003657206000012.png"\; state="\{\{state\}\}">V</figure-callout>}2}^{\&prime;\&prime;\&prime;}}{R2}-\frac{{\mathrm{<figure-callout\; id="3"\; label="V"\; filenames="HDA00003657206000011.png,HDA00003657206000032.png"\; state="\{\{state\}\}">V</figure-callout>}3}^{\&prime;\&prime;\&prime;}}{R3}),$ Calculate the negative pole insulating resistance value R of electrokinetic cell _n; Finally, microcontroller 1 utilizes the temperature obtained in step 1, the positive and negative electrode insulating resistance value R of the electrokinetic cell after the moisture signal correction calculation _p, R _n.

Step 5: microcontroller 1 is by the positive and negative electrode insulating resistance value R of the electrokinetic cell after proofreading and correct in step 3 or step 4 _p, R _nwith predefined positive and negative electrode insulating resistance value R _p*, R _n* compare, whether the judgement insulation is qualified; Defective if insulate (having fault), microcontroller 1 is exported a logic low, this logic low is exported high level to external unit after phase inverter is reverse, qualified if insulate (not having fault), microcontroller 1 is exported a logic high, and this logic high output low level after phase inverter is reverse arrives external unit; Microcontroller 1 is the temperature in electrokinetic cell, humidity, the positive and negative electrode insulating resistance value R of the electrokinetic cell after correction _p, R _nand the insulation whether qualified signal sends on the CAN bus.

Claims (4)

1. the insulation resistance detection system of an electric automobile power battery, is characterized in that: comprise microcontroller (1), insulation detecting circuit (2), filtering circuit (3), auxiliary high-voltage power supply (4), temperature sensor (5), humidity sensor (6), phase inverter (7) and CAN communicating circuit (8); Described microcontroller (1) is connected with auxiliary high-voltage power supply (4), control auxiliary high-voltage power supply work, auxiliary high-voltage power supply (4) is connected with the input end of insulation detecting circuit (2), and the outer low pressure direct current is converted to high voltage direct current, is input in insulation detecting circuit; Microcontroller (1) is connected with the control end of insulation detecting circuit (2), controls the interior electronic switch closes of insulation detecting circuit/disconnection; Microcontroller (1) is connected with the voltage output end of insulation detecting circuit (2) by filtering circuit (3), under described electronic switch closes/disconnection different conditions, microcontroller gathers the output voltage of insulation detecting circuit, and the positive and negative electrode insulating resistance value that carries out the judgement of electrokinetic cell on-line/off-line state and electrokinetic cell calculates; Microcontroller (1) is connected with temperature sensor (5), humidity sensor (6), obtains insulation detecting circuit temperature, moisture signal on every side, and proofreaies and correct the positive and negative electrode insulating resistance value of electrokinetic cell; Microcontroller (1) is connected with phase inverter (7), and the positive and negative electrode insulating resistance value of the electrokinetic cell after calculating and proofreading and correct and predefined positive and negative electrode insulating resistance value are compared, and whether the judgement insulation is qualified, and exports corresponding logic level; Microcontroller (1) is connected with CAN communicating circuit (8), by temperature, humidity, calculating and the positive and negative electrode insulating resistance value of the electrokinetic cell after proofreading and correct and insulation whether qualified signal sends on the CAN bus.

2. the insulation resistance detection system of electric automobile power battery according to claim 1 is characterized in that: described insulation detecting circuit (2) consists of first, second, third, fourth electronic switch (S1, S2, S3, S4) and the first, second, third, fourth, the 5th, the 6th resistance (R1, R2, R3, R4, R5, R6); One end of the first electronic switch (S1) connects the positive pole of electrokinetic cell by total positive relay (K1), the negative pole of one end of one end of another termination the first resistance (R1), the 4th resistance (R4) and auxiliary high-voltage power supply (4), one end of another termination the second resistance (R2) of the first resistance (R1), the other end ground connection of the second resistance (R2), one end of another termination the 5th resistance (R5) of the 4th resistance (R4), the other end ground connection of the 5th resistance (R5); One end ground connection of the 3rd resistance (R3), one end of another termination the 6th resistance (R6), one end of another termination the second electronic switch (S2) of the 6th resistance (R6) and an end of quadrielectron switch (S4), the other end of the second electronic switch (S2) connects the negative pole of electrokinetic cell, the positive pole of the auxiliary high-voltage power supply (4) of another termination of quadrielectron switch (S4) by total negative relay (K2); One termination the first resistance (R1) of the 3rd electronic switch (S3) and the tie point of the second resistance (R2), the positive pole of the auxiliary high-voltage power supply (4) of another termination of the 3rd electronic switch (S3); The control termination microcontroller (1) of first, second, third, fourth electronic switch (S1, S2, S3, S4), the closure of reception microcontroller/disconnection is controlled; Second, third, the voltage output end of the 5th resistance (R2, R3, R5) connects microcontroller (1) by filtering circuit (3), microcontroller gathers second, third, the voltage on the 5th resistance (R2, R3, R5) is calculated.

3. the method that adopts detection system as claimed in claim 1 or 2 to be detected insulation resistance comprises:

Step 1: temperature, moisture signal around the insulation detecting circuit that microcontroller (1) Real-time Obtaining temperature sensor (5) and humidity sensor (6) transmit;

Step 2: microcontroller (1) is controlled auxiliary high-voltage power supply (4) and is not worked, portions of electronics switch closure, the portions of electronics switch controlled in insulation detecting circuit (2) disconnect, collection is through the output voltage of filtered insulation detecting circuit (2), with predetermined threshold value, compare, the judgement electrokinetic cell is in online or off-line state;

Step 3: if electrokinetic cell is in line states, microcontroller (1) is controlled auxiliary high-voltage power supply work, high voltage direct current is introduced to insulation detecting circuit (2), portions of electronics switch in microprocessor controls insulation detecting circuit (2) is closed, the portions of electronics switch disconnects, collection is through the output voltage of filtered insulation detecting circuit (2), calculate the positive and negative electrode insulating resistance value of electrokinetic cell, utilize the positive and negative electrode insulating resistance value of the electrokinetic cell after described temperature, moisture signal correction calculation;

Step 4: if electrokinetic cell is in off-line state, microcontroller (1) is controlled auxiliary high-voltage power supply work, high voltage direct current is introduced to insulation detecting circuit (2), portions of electronics switch in microprocessor controls insulation detecting circuit (2) is closed, the portions of electronics switch disconnects, collection is through the output voltage of filtered insulation detecting circuit (2), calculate the positive and negative electrode insulating resistance value of electrokinetic cell, utilize the positive and negative electrode insulating resistance value of the electrokinetic cell after described temperature, moisture signal correction calculation;

Step 5: positive and negative electrode insulating resistance value and the predefined positive and negative electrode insulating resistance value of the electrokinetic cell after proofreading and correct in step 3 or step 4 are compared, and whether the judgement insulation is qualified; By insulation, whether qualified logic level is exported by phase inverter; By the temperature in electrokinetic cell, humidity, whether qualified signal sends on the CAN bus for the positive and negative electrode insulating resistance value of the electrokinetic cell after correction and insulation.

4. the insulation resistance detection method of electric automobile power battery according to claim 3 is characterized in that:

In step 2, microcontroller (1) is controlled first, second electronic switch (S1, the S2) closure in insulation detecting circuit (2), three, quadrielectron switch (S3, S4) disconnects, and the voltage V2 on second resistance (R2) of collection insulation detecting circuit (2), with predetermined threshold value V ^*compare, if V2 is more than or equal to V ^*, electrokinetic cell is in line states, if V2 is less than V ^*, electrokinetic cell is in off-line state;

In step 3, microcontroller (1) is first controlled first, second electronic switch (S1, the S2) closure in insulation detecting circuit (2), three, quadrielectron switch (S3, S4) disconnects, the voltage V2 on second resistance (R2) of collection insulation detecting circuit (2), the voltage V3 on the 3rd resistance (R3), the voltage V5 on the 5th resistance (R5) storage; Then, microcontroller (1) is controlled described the first, the 3rd electronic switch (S1, S3) closure, the second, quadrielectron switch (S2, S4) disconnects, and gathers voltage V2 ', the voltage V5 ' on the 5th resistance (R5) storage on described the second resistance (R2); According to formula

calculate the anodal insulating resistance value R of electrokinetic cell _p; According to formula $R_n=\frac{R3+R6}{R3}*V3/(\frac{R4+R5}{R5}*\frac{V5}{R_p}+\frac{V5}{R5}+\frac{V2}{R2}-\frac{V3}{R3}),$ Calculate the negative pole insulating resistance value R of electrokinetic cell _n;

In step 4, microcontroller (1) is first controlled the first, the 3rd electronic switch (S1, S3) closure in insulation detecting circuit (2), the second, quadrielectron switch (S2, S4) disconnects, and gathers voltage V2 on second resistance (R2) of insulation detecting circuit (2) ", the 5th resistance (R5) on voltage V5 " storage; Then, microcontroller (1) control described first, second, quadrielectron switch (S1, S2, S4) closure, the 3rd electronic switch (S3) disconnects, and gathers the voltage V5 on voltage V2 on described the second resistance (R2) " ', the voltage V3 on the 3rd resistance (R3) " ', the 5th resistance (R5) " ' and storage; According to formula calculate the anodal insulating resistance value R of electrokinetic cell _p; According to formula $R_n=\frac{R3+R6}{R3}*{V3}^{\&prime;\&prime;\&prime;}/(\frac{R4+R5}{R5}*\frac{{V5}^{\&prime;\&prime;\&prime;}}{R_p}+\frac{{V5}^{\&prime;\&prime;\&prime;}}{R5}+\frac{{V2}^{\&prime;\&prime;\&prime;}}{R2}-\frac{{V3}^{\&prime;\&prime;\&prime;}}{R3}),$ Calculate the negative pole insulating resistance value R of electrokinetic cell _n.

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