TWI754583B - Electronic system and insulation resistance measuring method - Google Patents

Abstract

An electronic system and a insulation resistance measuring method are provided. The electronic system includes a battery, an insulation resistance measuring circuit, a power conditioning system and a controller. The battery includes a first and second terminals. The power conditioning system is coupled to the first and second terminals of the battery. The power conditioning system have a first capacitor and second capacitors respectively coupled to the first and second terminals of the battery. The controller is coupled to the insulation resistance measuring circuit and the power conditioning system. Before the insulation resistance measuring circuit measures resistance of the first and second terminals of the battery, the controller controls the power conditioning system to disconnect a connection between the first capacitor and the first terminal of the battery, and to disconnect a connection between the second capacitor and the second terminal of the battery.

Description

Electronic system and method of measuring insulation resistance

The present invention relates to a system and method, and more particularly, to an electronic system and a method for measuring insulation resistance.

With the popularization of electronic systems such as power equipment and electric vehicles, the demand for setting up a power conditioning system (PCS) in the electronic system to adjust the output power of the battery is also increasing. In order to meet the specification requirements for protection against electromagnetic interference (EMI), a capacitor with a specific capacitance value is usually set at both ends of the battery in an electronic system or a power conditioning system, so as to improve the use safety of the electronic system. However, when the electronic system measures the insulation resistance, the capacitors set to protect against electromagnetic interference often interfere with the measurement of the insulation resistance. In electronic systems, such errors often seriously affect the safety of electronic systems.

The present invention provides an electronic system and a method for measuring insulation resistance, which can improve the use safety of the electronic system.

The electronic system of the present invention includes a battery, an insulation resistance measurement circuit, a power conditioning system and a controller. The battery has a first end and a second end. The insulation resistance measurement circuit is coupled to the first end and the second end of the battery. The power conditioning system is coupled to the first end and the second end of the battery. The power conditioning system has a first capacitor and a second capacitor respectively coupled to the first end and the second end of the battery. The controller is coupled to the insulation resistance measurement circuit and the power conditioning system. Before the insulation resistance measuring circuit measures the impedance of the first end and the second end of the battery, the controller controls the power conditioning system to disconnect the first capacitor from the first end of the battery, and disconnect the second capacitor from the battery connection of the second end.

The method for measuring the insulation resistance of the present invention is suitable for measuring the impedance of the first end and the second end of the battery in the electronic system, and the method for measuring the insulation resistance comprises disconnecting the first capacitor of the power conditioning system in the electronic system from the battery The first terminal of the battery is connected, and the second capacitor of the power conditioning system in the electronic system is disconnected from the second terminal of the battery. Then, the impedances of the first and second ends of the battery are measured.

Based on the above, the electronic system and the method for measuring the insulation resistance of the present invention can also provide accurate insulation resistance measurement while meeting the requirements of electromagnetic interference specifications, thereby effectively improving the safety of users when using the electronic system.

FIG. 1A is a schematic diagram of an electronic system 1 according to an embodiment of the present invention. The electronic system 1 includes a battery BAT, an insulation resistance measurement circuit 10 , a power conditioning system (PCS) 11 and a controller 12 . The battery BAT can provide power to the electronic system 1 . The insulation resistance measuring circuit 10 is coupled to the two ends B+ and B- of the battery BAT. The insulation resistance measuring circuit 10 can be used to measure the insulation resistance of the two terminals B+ and B- of the battery BAT relative to the ground terminal. The power conditioning system 11 includes capacitors Cy1 and Cy2, which are respectively coupled to two ends B+ and B- of the battery BAT through switches SW1 and SW2. The controller 12 is coupled to the insulation resistance measurement system 10 and the power conditioning system 11 , and controls the operations of the insulation resistance measurement system 10 and the power conditioning system 11 . Roughly speaking, the controller 12 can first control the switches SW1 and SW2 in the power conditioning system 11 to be turned off (cut off), and then control the insulation resistance circuit 10 to measure the insulation of the two ends B+ and B- of the battery BAT relative to the ground. impedance. Therefore, in the process of measuring the insulation resistance of the electronic system 1 , the measurement can be performed accurately without being affected by the capacitances Cy1 and Cy2 , thereby improving the overall safety of the electronic system 1 .

In one embodiment, the electronic system 1 may be a system of an electric vehicle, an electric vehicle, a power system, an energy storage power supply station, or the like. The battery BAT can supply power to the electronic system 1 through both ends B+ and B- to operate. The insulation resistance measurement circuit 10 is coupled to the two ends B+ and B- of the battery BAT. The insulation resistance measurement circuit 10 can measure the impedances of the two ends B+ and B- of the battery BAT respectively, and provide the measurement results to the controller 12 .

In one embodiment, the power conditioning system 11 may be applied to regulate the electrical power provided by the battery BAT. For example, the power conditioning system 11 can be applied to an inverter of an energy storage system or a motor driver of an electric vehicle. The power conditioning system 11 may be used to regulate the battery BAT electrical power. Part of the circuit structure of the power conditioning system 11 is omitted in FIG. 1A , but it can be changed and applied to the power conditioning system 1 by those skilled in the art according to different design requirements. For example, the circuit structure not shown in the power conditioning system 11 may include, for example, a circuit structure for sensing and providing appropriate three-phase power to the electronic system 1 .

Further, in order to meet the specification requirements for electromagnetic interference (EMI) protection in the electronic system 1 , the power conditioning system 11 may include capacitors Cy1 and Cy2 , respectively coupled to the two ends B+ and B- of the battery BAT. In one embodiment, the capacitance values of the capacitors Cy1 and Cy2 may be between 0 microfarad (uF) and 1.2 microfarad. In one embodiment, the capacitance values of the capacitors Cy1 and Cy2 may be 1.2 microfarads. The capacitor Cy1 can be coupled to one end B+ of the battery BAT through the switch SW1. The capacitor Cy2 can be coupled to the other end B- of the battery BAT through the switch SW2. The switches SW1 and SW2 can be turned on (switched in) or turned off (switched off) to control whether the capacitors Cy1 and Cy2 are coupled to the two ends B+ and B- of the battery BAT. In one embodiment, when the electronic system 1 is in normal operation, that is, when the power regulation system 11 is regulating the power of the battery BAT, the switches SW1 and SW2 can be turned on to couple the capacitors Cy1 and Cy2 to both ends of the battery BAT. B+, B-. In one embodiment, the withstand voltage of the switches SW1 and SW2 can reach twice the rated voltage of the battery BAT plus one thousand volts. When the electronic system 1 performs the insulation resistance measurement operation, the switches SW1 and SW2 can be disconnected to connect the capacitors Cy1 and Cy2 to the two ends B+ and B- coupled to the battery BAT, so as to prevent the capacitors Cy1 and Cy2 from affecting the insulation. Accuracy of impedance measurement operations.

The controller 12 is coupled to the insulation resistance measurement circuit 10 and the power conditioning system 11 . The controller 11 can control the operations of the insulation resistance measurement circuit 10 and the power conditioning system 11 . The controller 10 can switch on or off the switches SW1 and SW2 in the power conditioning system 11 to preferably control the insulation resistance measurement circuit 10 to measure the impedances B+ and B- at both ends of the battery BAT.

The controller 12 can be, for example, a Central Processing Unit (CPU), or other programmable general-purpose or special-purpose Micro Control Unit (Micro Control Unit, MCU), microprocessor (Microprocessor), digital signal Digital Signal Processor (DSP), Programmable Controller, Application Specific Integrated Circuit (ASIC), Graphics Processing Unit (GPU), Arithmetic Logic Unit (ALU) ), Complex Programmable Logic Device (CPLD), Field Programmable Gate Array (FPGA), any other kind of integrated circuit, state machine, Advanced Reduced Instruction Set-based machine (Advanced RISC Machine, ARM) processor, or other similar elements or a combination of the above elements. Alternatively, the controller 12 can be designed through a hardware description language (HDL) or any other digital circuit design methods well known to those skilled in the art, and can be designed through a field programmable logic gate array ( Field Programmable Gate Array, FPGA), Complex Programmable Logic Device (Complex Programmable Logic Device, CPLD) or Application-specific Integrated Circuit (Application-specific Integrated Circuit, ASIC) The way to realize the hardware circuit, the present invention is here. The implementation of the controller 12 is not limited.

FIG. 1B is a flowchart of a method for measuring insulation resistance according to an embodiment of the present invention. The measurement method of insulation resistance in FIG. 1B can be applied to the electronic system 1 in FIG. 1A to make the electronic system 1 perform. Next, please refer to FIGS. 1A and 1B together to understand the description about the measurement method of the insulation resistance. The method for measuring insulation resistance includes steps S10 and S11. In step S10 , the controller 12 may control the power conditioning system 11 to disconnect the capacitors Cy1 and Cy2 in the power conditioning system 11 from the two terminals B+ and B− of the battery BAT. In step S11 , the controller 11 can control the insulation resistance measuring circuit 10 to measure the impedances B+ and B− at both ends of the battery BAT.

Specifically, in step S10 , the controller 12 can control the switches SW1 and SW2 in the power conditioning system 11 to be off, so as to disconnect the connections between the capacitors Cy1 and Cy2 and the terminals B+ and B- of the battery BAT, respectively. Next, after the connections between the capacitors Cy1 and Cy2 and the terminals B+ and B- of the battery BAT are disconnected, step S11 is performed to measure the impedance of the terminals B+ and B- of the battery BAT.

Therefore, the process of measuring the insulation resistance of the electronic system 1 can be effectively improved, and the results of the insulation resistance measurement can be accurately measured without being affected by the capacitances Cy1 and Cy2 , thereby improving the overall safety of the electronic system 1 .

FIG. 2A is a schematic diagram of an electronic system 2 according to an embodiment of the present invention. The electronic system 2 shown in FIG. 2A is similar to the electronic system 1 shown in FIG. 1A , except that the insulation resistance measurement circuit 10 in the electronic system 1 is replaced by an insulation resistance measurement circuit 20 in the electronic system 2 of the electronic system 2 . In the electronic systems 1 and 2 , the same components are represented by the same symbols, that is, the battery BAT, the power conditioning system 11 and the controller 12 . Therefore, for the description of these circuits, please refer to the relevant paragraphs about the electronic system 1 above, which will not be repeated here.

Specifically, the insulation resistance measurement circuit 20 includes impedances Rp and Rn, an impedance reference circuit 200 and a voltage division sensing circuit 201 . The impedances Rp and Rn are the impedances B+ and B- at both ends of the battery BAT in the electronic system 2 , and the insulation resistance measurement circuit 20 can measure the impedances Rp and Rn. More specifically, the insulation impedance circuit 20 can measure the voltage values of B+ and B- at both ends of the battery BAT through the voltage divider sensing circuit 201 , and calculate the impedances Rp and Rn through the impedance of known resistance values in the impedance reference circuit 200 . .

The impedance reference circuit 200 includes resistors R1 and R2 and switches SW3 and SW4 . The resistor R1 and the switch SW3 are connected in series between one end B+ of the battery BAT and the ground end Gnd, and the switch SW4 is connected in series between the other end B- of the battery BAT and the ground end Gnd. The switches SW3 and SW4 can be controlled by the controller 12 so that the resistors R1 and R2 are respectively coupled to or disconnected from the two terminals B+ and B- of the battery BAT.

The voltage division sensing circuit 201 includes resistors R3 to R6 and switches SW5 and SW6. The resistors R3, R4, and the switch SW5 are connected in series between one end B+ of the battery BAT and the ground end Gnd; the resistors R5, R6, and the switch SW6 are connected in series between the other end B- of the battery BAT and the ground end Gnd. The switches SW5 and SW6 can be controlled by the controller 12 to respectively couple or disconnect the resistor strings R3 and R4 and the resistor strings R5 and R6 to the two ends B+ and B- of the battery BAT.

2B is a flowchart of a method for measuring insulation resistance according to an embodiment of the present invention. The measurement method of insulation resistance shown in FIG. 2B can be applied to the electronic system 2A shown in FIG. 2A , so please refer to FIGS. 2A and 2B together to understand the following description of the measurement method of insulation resistance.

In FIG. 2B , the method for measuring insulation resistance includes steps S20 to S28. In step S20, the controller 12 of the electronic system 2 can disconnect the capacitors Cy1 and Cy2 of the power conditioning system 11 from the connection between the two terminals B+ and B- of the battery, respectively. In step S21 , the electronic system 2 can sense the voltages Vp1 and Vn1 of the two terminals B+ and B− of the battery BAT through the voltage dividing sensing circuit 201 . In step S22, the electronic system 2 can use the controller 12 to compare the voltages Vp1 and Vn1 sensed by the two terminals B+ and B- of the battery BAT, so that the controller 12 can control the impedance reference circuit 200 according to the comparison results of the voltages Vp1 and Vn1. operation. When the voltage Vp1 of one end B+ of the battery BAT is greater than the voltage Vn1 of the other end B- of the battery BAT, steps S23 to S25 are executed. Conversely, when the voltage Vn1 of the other end B- of the battery BAT is greater than the voltage Vp1 of the end B+ of the battery BAT, steps S26 to S28 are executed. In step S23, the electronic system 2 can control the switch SW4 in the impedance reference circuit 200 to be turned on and the switch SW3 to be turned off by the controller 12 to connect the resistor R2 to the other end B- of the battery BAT. In step S24, the electronic system 2 can sense the voltages Vp2 and Vn2 of the two ends B+ and B- of the battery BAT through the voltage dividing sensing circuit 201 . In step S25 , the electronic system 2 can calculate the impedances B+ and B- at both ends of the battery BAT through the controller 12 . Similarly, in step S26, the electronic system 2 can control the switch SW3 in the impedance reference circuit 200 to be turned on and the switch SW4 to be turned off by the controller 12 to connect the resistor R1 to one end B+ of the battery BAT. In step S24, the electronic system 2 can sense the voltages Vp2 and Vn2 of the two ends B+ and B- of the battery BAT through the voltage dividing sensing circuit 201 . In step S25 , the electronic system 2 can calculate the impedances B+ and B- at both ends of the battery BAT through the controller 12 .

Specifically, in step S20 , the controller 12 can control the switches SW1 and SW2 in the power conditioning system 11 to be turned off, so as to disconnect the connections between the capacitors Cy1 and Cy2 and the terminals B+ and B- of the battery BAT, respectively. Next, after the connections between the capacitors Cy1 and Cy2 and the terminals B+ and B- of the battery BAT are disconnected, steps S21 to S28 are performed to measure the impedance of the terminals B+ and B- of the battery BAT.

In step S21, the controller 12 can control the switches SW5 and SW6 in the voltage dividing sensing circuit 201 to be turned on, so that the controller 12 can judge the two terminals B+, V2 of the battery BAT according to the voltages V1 and V2 of the resistors R4 and R5 respectively. B - Voltage Vp1, Vn1, respectively.

In step S22, the controller 12 may compare the voltages of the voltages Vp1 and Vn1 to control the impedance reference circuit 200 to perform subsequent measurement operations.

In step S23, when the controller 12 determines that the voltage Vp1 is greater than the voltage Vn1, the resistance value of the representative impedance Rp is greater than the resistance value of the impedance Rn, and the controller 12 can control the switch SW4 in the impedance reference circuit 200 to be turned on, so that the resistance R2 is turned on. Connect to the other end of the battery BAT B-.

In step S24, the controller 12 can sense the voltages Vp2 and Vn2 at the two ends of the battery B+ and B-, respectively, by using the voltage division sensing circuit 201 . And in step S25 , the controller 12 can calculate the resistance values of the impedances Rp and Rn according to the voltages Vp1 , Vn1 , Vp2 and Vn2 .

接著，當Vn1大於Vp1時，代表阻抗Rp的阻抗較小，因此控制器12可於步驟S26中控制阻抗參考電路200導通開關SW3以將電阻R1耦接至電池BAT的一端B+上，再於步驟S27中量測電池BAT兩端B+、B-分別的電壓Vp2、Vn2。相似於上式，Vp2、Vn2會與滿足以下關係。

In one embodiment, the voltages Vp1 and Vn1 sensed by the electronic system 2 in step S21 are proportional to the impedances Rp and Rn, and satisfy the following relationships.

Next, when Vn1 is greater than Vp1, it means that the impedance of the impedance Rp is relatively small, so the controller 12 can control the impedance reference circuit 200 to turn on the switch SW3 in step S26 to couple the resistor R1 to one end B+ of the battery BAT, and then in step S26 In S27, the voltages Vp2 and Vn2 of the two terminals B+ and B- of the battery BAT are measured respectively. Similar to the above formula, Vp2, Vn2 will satisfy the following relationship.

In this way, in step S25, the controller 12 can solve the simultaneous relationship according to the above two relational expressions, and calculate the resistance values of the impedances Rp and Rn according to the resistance values of Vp1, Vp2, Vn1, Vn2 and the resistance R2 as follows.

In addition, the switching, measurement and calculation processes of the electronic system 2 in steps S23-S25 are similar to the above, and therefore are not described in detail here.

Therefore, the electronic system 2 and the method for measuring the insulation resistance can disconnect the capacitors Cy1 and Cy2 from the two ends B+ and B- of the battery BAT before measuring the insulation resistance, and then measure the resistance Rp according to the known resistance value. The resistance value of Rn and Rn is measured, which can effectively avoid the influence of the capacitance Cy1 and Cy2 on the measurement of the insulation resistance, so it can effectively improve the safety of the user when using the electronic system.

To sum up, the electronic system and the method for measuring insulation resistance of the present invention can also provide accurate insulation resistance measurement while meeting the requirements of electromagnetic interference specifications, thereby effectively improving the use of electronic systems by users Safety.

1, 2: Electronic system 10, 20: Insulation resistance measurement circuit 11: Power conditioning system 12: Controller 200: Impedance Reference Circuit 201: Voltage divider sensing circuit BAT: battery B+, B-: terminal Cy1, Cy2: Capacitance S10, S11, S20～S28: Steps R1～R6: Resistance Rp, Rn: Impedance SW1, SW2, SW3, SW4, SW5, SW6: Switches V1, V2: Voltage

1A is a schematic diagram of an electronic system according to an embodiment of the present invention FIG. 1B is a flowchart of a method for measuring insulation resistance according to an embodiment of the present invention. 2A is a schematic diagram of an electronic system according to an embodiment of the present invention 2B is a flowchart of a method for measuring insulation resistance according to an embodiment of the present invention.

1: Electronic system

10: Insulation resistance measurement circuit

11: Power conditioning system

12: Controller

BAT: battery

B+, B-: terminal

Cy1, Cy2: Capacitance

SW1, SW2: switch

Claims (11)

An electronic system comprising: a battery having a first end and a second end; an insulation resistance measuring circuit, coupled to the first end and the second end of the battery; A power conditioning system (PCS) is coupled to the first end and the second end of the battery. The power conditioning system has a first capacitor and a second capacitor respectively coupled to the first end and the second end of the battery. the second end; and a controller, coupled to the insulation resistance measurement circuit and the power conditioning system, Wherein, before the insulation resistance measurement circuit measures the impedance of the first end and the second end of the battery, the controller controls the power conditioning system to disconnect the first capacitor from the first end of the battery, and the second the connection of the capacitor to the second terminal of the battery. The electronic system of claim 1, wherein capacitance values of the first capacitor and the second capacitor are between 0 microfarad (uF) and 1.2 microfarad. The electronic system of claim 1, wherein the power conditioning system comprises: a first switch, coupled between the first end of the battery and the first capacitor; and a second switch, coupled between the second end of the battery and the second capacitor, Wherein, before the insulation resistance measuring circuit measures the impedance of the first end and the second end of the battery, the first switch and the second switch are controlled by the controller to be turned off. The electronic system of claim 1, wherein the insulation resistance measurement circuit further comprises a first resistor and a second resistor, After measuring a first voltage and a second voltage of the first and second terminals of the battery, the controller couples the first resistor to the the first end of the battery, or the second resistor is coupled to the second end of the battery. The electronic system according to claim 4, wherein the insulation resistance circuit is connected to the first end of the battery or the second resistance is connected to the second end of the battery after the first resistance is connected to the second end of the battery, the insulation resistance measurement circuit measuring a third voltage and a fourth voltage at the first end and the second end of the battery, The controller calculates the impedance of the first terminal and the second terminal of the battery according to the first voltage, the second voltage, the third voltage and the fourth voltage. The electronic system of claim 4, wherein the insulation resistance measurement circuit further comprises: a third switch, coupled to the controller, the third switch and the first resistor are connected in series between the first terminal of the battery and a ground terminal; and a fourth switch, coupled to the controller, the fourth switch and the second resistor are connected in series between the second terminal of the battery and the ground terminal, When the first voltage is greater than the second voltage, the controller controls the third switch to be turned off and the fourth switch to be turned on, and when the second voltage is greater than the first voltage, the controller controls the third switch The switch is on and the fourth switch is off. A method for measuring insulation resistance, suitable for measuring the impedance of a first terminal and a second terminal of a battery in an electronic system, the method for measuring insulation resistance includes: Disconnecting a first capacitor of a power conditioning system (PCS) in the electronic system from the first end of the battery, and disconnecting a second capacitor of the power conditioning system in the electronic system from the battery connection of the second end of the battery; then The impedances of the first and second ends of the battery are measured. The method for measuring insulation resistance as claimed in claim 7, wherein a first capacitor of the power conditioning system in the electronic system is disconnected from the first end of the battery, and the power conditioning in the electronic system is disconnected The step of connecting the second capacitor of the system to the second end of the battery includes: Disconnecting a first switch coupled between the first end of the battery and the first capacitor in the power conditioning system, and disconnecting the second end and the second end of the power conditioning system coupled to the battery A second switch between the capacitors. The method for measuring insulation resistance according to claim 7, further comprising: After measuring a first voltage and a second voltage of the first terminal and the second terminal of the battery, a first resistor is coupled to the first voltage of the battery according to the comparison result of the first voltage and the second voltage terminal, or a second resistor is coupled to the second terminal of the battery. The method for measuring insulation resistance according to claim 9, wherein after the step of coupling the first resistance to the first end of the battery, or coupling the second resistance to the second end of the battery, further include: The measurement circuit measures a third voltage and a fourth voltage at the first terminal and the second terminal of the battery; and The impedance of the first terminal and the second terminal of the battery is calculated according to the first voltage, the second voltage, the third voltage and the fourth voltage. The method for measuring insulation resistance as claimed in claim 9, wherein a third switch and the first resistor are connected in series between the first terminal of the battery and a ground terminal, and a fourth switch and the second resistor are connected in series Connected between the second end of the battery and the ground end, wherein the step of coupling the first resistor to the first end of the battery, or coupling the second resistor to the second end of the battery includes: when the first voltage is greater than the second voltage, controlling the third switch to be turned off and the fourth switch to be turned on, and When the second voltage is greater than the first voltage, the third switch is controlled to be turned on and the fourth switch is turned off.

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