Insulation resistance detection device
阅读说明：本技术 绝缘电阻检测装置 (Insulation resistance detection device ) 是由 林保泓 陈柏燊 郑国和 张明俊 林才富 于 2018-11-01 设计创作，主要内容包括：本发明公开了一种绝缘电阻检测装置包括一检测单元、一控制单元及一计算单元。检测单元包括一电路模块、一第一开关、一第二开关、一检测节点及一电压检测装置,电路模块由多个固定电阻连接组成,且电路模块并联在一高压电池组的一正极与一负极之间,第一开关连接于电路模块与一接地端之间,所述第二开关连接于电路模块与负极之间,检测节点设置在电路模块中的固定电阻连接节点其中之一节点位置,并在检测节点位置外接电压检测装置。控制单元用于控制第一开关与第二开关的断开或接通状态。计算单元用于运算电压检测装置检测的电压并计算得到一高电位绝缘电阻值与一低电位绝缘电阻值。(The invention discloses an insulation resistance detection device which comprises a detection unit, a control unit and a calculation unit. The detection unit comprises a circuit module, a first switch, a second switch, a detection node and a voltage detection device, wherein the circuit module is formed by connecting a plurality of fixed resistors, the circuit module is connected between an anode and a cathode of a high-voltage battery pack in parallel, the first switch is connected between the circuit module and a grounding terminal, the second switch is connected between the circuit module and the cathode, and the detection node is arranged at one node position of the fixed resistor connection nodes in the circuit module and is externally connected with the voltage detection device at the detection node position. The control unit is used for controlling the off or on states of the first switch and the second switch. The calculating unit is used for calculating the voltage detected by the voltage detecting device and calculating a high potential insulation resistance value and a low potential insulation resistance value.)
1. An insulation resistance detecting apparatus for detecting an insulation resistance value between a high voltage battery pack and a ground terminal in a main battery system, wherein the main battery system includes a main switch connected in series with the high voltage battery pack, the main switch is controlled by a battery power management system, a high potential insulation resistance is considered to be present between an anode of the high voltage battery pack and the ground terminal, and a low potential insulation resistance is considered to be present between a cathode of the high voltage battery pack and the ground terminal, the apparatus comprising:
the detection unit comprises a circuit module, a first switch, a second switch, a detection node and a voltage detection device, wherein the circuit module is formed by connecting a plurality of fixed resistors, the circuit module is connected between the anode and the cathode in parallel, the first switch is connected between the circuit module and the grounding terminal, the second switch is connected between the circuit module and the cathode, the detection node is arranged at one node position of a plurality of fixed resistor connection nodes in the circuit module, and the detection node is externally connected with the voltage detection device at the detection node position;
the control unit is connected with the first switch and the second switch and is used for controlling the off or on states of the first switch and the second switch;
a calculation unit connected to the voltage detection device for receiving the voltage detected by the voltage detection device and performing multiple formula operations to obtain a high potential insulation resistance and a low potential insulation resistance, wherein
When the first switch is turned off and the second switch is turned off, the voltage detection device detects a first voltage of the detection node, and then the calculation unit derives a second voltage by using the first voltage;
when the first switch is turned on and the second switch is turned off, the voltage detection device detects a third voltage of the detection node, and then the calculation unit derives a fourth voltage by using the third voltage;
when the first switch is turned on and the second switch is turned on, the voltage detection device detects a fifth voltage of the detection node, and then the calculation unit derives a sixth voltage by using the fifth voltage;
after the second voltage, the fourth voltage and the sixth voltage are obtained, the computing unit subtracts the fourth voltage from the second voltage to obtain a seventh voltage, and the computing unit subtracts the sixth voltage from the second voltage to obtain an eighth voltage;
the calculation unit combines the fourth voltage, the sixth voltage, the seventh voltage and the eighth voltage into a first function;
the calculation unit establishes formulas respectively when the first switch is switched on and the second switch is switched off and when the first switch is switched on and the second switch is switched on, and further calculates a low potential insulation resistance operation formula and a high potential insulation resistance operation formula, wherein the two operation formulas are operation formulas consisting of the first function, the fourth voltage, the seventh voltage and each fixed resistor.
2. The insulation resistance detecting apparatus according to claim 1, wherein: the first function defining symbol isMThe first function
Wherein Vn is a fourth voltage, Vn 'is a sixth voltage, Vp is a seventh voltage, and Vp' is an eighth voltage.
3. The insulation resistance detecting apparatus according to claim 1, wherein: each fixed resistor is a first fixed resistor Ra, a second fixed resistor Rb, a third fixed resistor Rc and a fourth fixed resistor Rd, the first fixed resistor Ra is sequentially connected in series to the fourth fixed resistor Rd, one end of the first fixed resistor Ra is connected to the positive pole, and one end of the fourth fixed resistor Rd is connected to the negative pole.
4. The insulation resistance detecting apparatus according to claim 3, wherein: the first switch is connected between the first fixed resistor Ra and the second fixed resistor Rb, the second switch is connected between the third fixed resistor Rc and the fourth fixed resistor Rd, and a connection node of the second fixed resistor Rb and the third fixed resistor Rc is the position of the detection node.
5. The insulation resistance detecting apparatus according to claim 4, wherein: wherein the low potential insulation resistance is defined by a symbol Rn, and the low potential insulation resistance Rn has the following formula:
and the high potential insulation resistance definition symbol is Rp, and the operational formula of the high potential insulation resistance Rp is as follows:
whereinMWhere Vn is a fourth voltage, Vp is a seventh voltage, Ra is a first fixed resistor, Rb is a second fixed resistor, Rc is a third fixed resistor, and Rd is a fourth fixed resistor.
6. The insulation resistance detecting apparatus according to claim 1, wherein: wherein the circuit module includes a first fixed resistance Ra, a second fixed resistance Rb, a third fixed resistance Rc and a fourth fixed resistance Rd, first fixed resistance Ra, second fixed resistance Rb with third fixed resistance Rc forms the series connection, just first fixed resistance Ra one end connect in anodal, the one end of third fixed resistance Rc connect in the negative pole, fourth fixed resistance Rd one end connect in first fixed resistance Ra with the connected node position of second fixed resistance Rb, the fourth fixed resistance Rd other end is connected the second switch, just the second switch other end connect in the negative pole, therefore parallelly connected second fixed resistance Rb and third fixed resistance Rc of fourth fixed resistance Rd.
7. The insulation resistance detecting apparatus according to claim 6, wherein: the first switch is connected between the first fixed resistor Ra and the second fixed resistor Rb, and a connection node between the second fixed resistor Rb and the third fixed resistor Rc is a position of the detection node.
8. The insulation resistance detecting apparatus according to claim 6, wherein: the low potential insulation resistance is defined by a symbol Rn, and the operational expression of the low potential insulation resistance Rn is as follows:
and the high potential insulation resistance definition symbol is Rp, and the operational formula of the high potential insulation resistance Rp is as follows:
whereinMIs a first function, Vn is the fourth voltage, Vp is the seventh voltage, Ra is a first fixed resistorRb is a second fixed resistor, Rc is a third fixed resistor, and Rd is a fourth fixed resistor.
9. The insulation resistance detecting apparatus according to claim 1, wherein: the battery management system further comprises an external voltage module, wherein the external voltage module comprises a fixed voltage source, a third switch and a fourth switch, the fixed voltage source and the third switch are connected in series between the positive electrode and the negative electrode, the fourth switch is connected in series between the positive electrode and the power battery management system, the battery management system can control the connection or disconnection of the third switch and the fourth switch, the fourth switch is in a disconnection state when the third switch is connected, and the fourth switch is in a connection state when the third switch is disconnected.
Technical Field
The invention relates to a device for detecting insulation resistance, in particular to an insulation resistance detection device for a vehicle.
Background
As shown in fig. 1, a conventional
However, in the case of an electric vehicle, due to environmental factors such as rain, wading, vibration, and temperature change or a traffic accident, the original insulation resistance is easily reduced, which may cause an electric shock to the personnel.
As shown in fig. 2 to 4, the conventional insulation
The detection steps are as follows: firstly, the first voltage detection device and the second voltage detection device are used for detecting and obtaining the voltage between the end points, then the values of the trans-voltages Vp and Vn of the insulation resistors Rp and Rn before the switch 821 is switched on and the values of the trans-voltages Vp 'and Vn' after the switch 821 is switched on are calculated, a circuit formula is shown in the drawing, the insulation resistors Rp and Rn are obtained by solving, and the calculation formula is shown as follows.
Although the
Therefore, an insulation resistance detection device which is low in cost and can accurately measure insulation resistance needs to be designed to ensure the safety of the battery pack to human bodies.
Disclosure of Invention
The present invention is directed to provide an insulation resistance detection device, which overcomes the above-mentioned drawbacks of the conventional design.
In order to achieve the above object, the present invention provides an insulation resistance detection apparatus for detecting an insulation resistance value between a high voltage battery pack and a ground terminal in a main battery system, wherein the main battery system includes a main switch connected in series with the high voltage battery pack, the main switch is controlled by a battery power management system, a high potential insulation resistance is deemed to be present between an anode of the high voltage battery pack and the ground terminal, and a low potential insulation resistance is deemed to be present between a cathode of the high voltage battery pack and the ground terminal, the apparatus comprising:
the detection unit comprises a circuit module, a first switch, a second switch, a detection node and a voltage detection device, wherein the circuit module is formed by connecting a plurality of fixed resistors, the circuit module is connected between the anode and the cathode in parallel, the first switch is connected between the circuit module and the grounding terminal, the second switch is connected between the circuit module and the cathode, the detection node is arranged at one node position of a plurality of fixed resistor connection nodes in the circuit module, and the detection node is externally connected with the voltage detection device at the detection node position;
the control unit is connected with the first switch and the second switch and is used for controlling the off or on states of the first switch and the second switch;
a calculation unit connected to the voltage detection device for receiving the voltage detected by the voltage detection device and performing multiple formula operations to obtain a high potential insulation resistance and a low potential insulation resistance, wherein
When the first switch is turned off and the second switch is turned off, the voltage detection device detects a first voltage of the detection node, and then the calculation unit derives a second voltage by using the first voltage;
when the first switch is turned on and the second switch is turned off, the voltage detection device detects a third voltage of the detection node, and then the calculation unit derives a fourth voltage by using the third voltage;
when the first switch is turned on and the second switch is turned on, the voltage detection device detects a fifth voltage of the detection node, and then the calculation unit derives a sixth voltage by using the fifth voltage;
after the second voltage, the fourth voltage and the sixth voltage are obtained, the computing unit subtracts the fourth voltage from the second voltage to obtain a seventh voltage, and the computing unit subtracts the sixth voltage from the second voltage to obtain an eighth voltage;
the calculation unit combines the fourth voltage, the sixth voltage, the seventh voltage and the eighth voltage into a first function;
the calculation unit establishes formulas respectively when the first switch is switched on and the second switch is switched off and when the first switch is switched on and the second switch is switched on, and further calculates a low potential insulation resistance operation formula and a high potential insulation resistance operation formula, wherein the two operation formulas are operation formulas consisting of the first function, the fourth voltage, the seventh voltage and each fixed resistor.
As a further improvement, the first function definition symbol isMThe first function
Wherein Vn is a fourth voltage, Vn 'is a sixth voltage, Vp is a seventh voltage, and Vp' is an eighth voltage.
As a further improvement, each of the fixed resistors is a first fixed resistor Ra, a second fixed resistor Rb, a third fixed resistor Rc, and a fourth fixed resistor Rd, the first fixed resistor Ra is sequentially connected in series to the fourth fixed resistor Rd, and one end of the first fixed resistor Ra is connected to the positive electrode, and one end of the fourth fixed resistor Rd is connected to the negative electrode.
In a further improvement, the first switch is connected between the first fixed resistor Ra and the second fixed resistor Rb, the second switch is connected between the third fixed resistor Rc and the fourth fixed resistor Rd, and a connection node between the second fixed resistor Rb and the third fixed resistor Rc is a position of the detection node.
As a further improvement, the low potential insulation resistance is defined by a symbol Rn, and the operational expression of the low potential insulation resistance Rn is:
and the high potential insulation resistance definition symbol is Rp, and the operational formula of the high potential insulation resistance Rp is as follows:
whereinMWhere Vn is a fourth voltage, Vp is a seventh voltage,ra is a first fixed resistor, Rb is a second fixed resistor, Rc is a third fixed resistor, and Rd is a fourth fixed resistor.
As a further improvement, the circuit module includes a first fixed resistor Ra, a second fixed resistor Rb, a third fixed resistor Rc, and a fourth fixed resistor Rd, the first fixed resistor Ra, the second fixed resistor Rb and the third fixed resistor Rc are connected in series, one end of the first fixed resistor Ra is connected to the positive pole, one end of the third fixed resistor Rc is connected to the negative pole, one end of the fourth fixed resistor Rd is connected to a connection node position of the first fixed resistor Ra and the second fixed resistor Rb, the other end of the fourth fixed resistor Rd is connected to the second switch, and the other end of the second switch is connected to the negative pole, so that the fourth fixed resistor Rd connects the second fixed resistor Rb and the third fixed resistor Rc in parallel.
As a further improvement, the first switch is connected between the first fixed resistor Ra and the second fixed resistor Rb, and a connection node between the second fixed resistor Rb and the third fixed resistor Rc is a position of the detection node.
As a further improvement, the low potential insulation resistance is defined by a symbol Rn, and the operational expression of the low potential insulation resistance Rn is:
and the high potential insulation resistance definition symbol is Rp, and the operational formula of the high potential insulation resistance Rp is as follows:
whereinMWhere Vn is the fourth voltage, Vp is the seventh voltage, Ra is the first fixed resistor, Rb is the second fixed resistor, Rc is the third fixed resistor, and Rd is the fourth fixed resistor.
As a further improvement, the battery management system further comprises an external voltage module, the external voltage module comprises a fixed voltage source, a third switch and a fourth switch, the fixed voltage source and the third switch are connected in series between the positive electrode and the negative electrode, the fourth switch is connected in series between the positive electrode and the power battery management system, wherein the battery management system can control the connection or disconnection of the third switch and the fourth switch, and the fourth switch is in the disconnection state when the third switch is connected and in the connection state when the third switch is disconnected.
The insulation resistance detection device can obtain the insulation resistances Rn and Rp through arithmetic operation by the configuration combination of the circuit module in the detection unit and the first switch and the second switch, can completely disconnect the detection unit from the loop after the loop detection is finished, cannot reduce the insulation resistances Rn and Rp in use, and can detect in advance before the power supply of the main battery through the external voltage module so as to ensure the power supply safety.
Drawings
Fig. 1 is a schematic configuration diagram of a conventional electric vehicle including a high-voltage battery system and a power system.
Fig. 2 is a schematic diagram of a detection module in the conventional insulation resistance detection technology for an electric vehicle.
Fig. 3 is a schematic circuit diagram of a conventional insulation resistance detection technique.
Fig. 4 is a schematic circuit diagram of a switch of the prior art insulation resistance detection technology.
Fig. 5 is a schematic circuit diagram of the insulation resistance detection device according to the present invention.
Fig. 6 is a schematic circuit diagram of an insulation resistance detection apparatus according to a first embodiment of the present invention.
Fig. 7 is a schematic circuit diagram of a first embodiment of the present invention, in which the first switch is turned off and the second switch is turned off.
Fig. 8 is a schematic circuit diagram of a first embodiment of the present invention, in which the first switch is turned on and the second switch is turned off.
Fig. 9 is a schematic circuit diagram of a first embodiment of the present invention, in which the first switch is turned on and the second switch is turned on.
Fig. 10 is a schematic circuit diagram of an insulation resistance detection apparatus according to a second embodiment of the present invention.
Fig. 11 is a schematic circuit diagram of a second embodiment of the present invention, in which the first switch is turned off and the second switch is turned off.
Fig. 12 is a schematic circuit diagram of a second embodiment of the present invention, in which the first switch is turned on and the second switch is turned off.
Fig. 13 is a schematic circuit diagram of a second embodiment of the present invention, in which the first switch is turned on and the second switch is turned on.
Fig. 14 is a schematic circuit diagram of an insulation resistance detection apparatus according to a third embodiment of the present invention.
The reference numerals in the drawings are explained below.
91 high-voltage battery system of 90 electric automobile
911
92 power
931
81
812
821 switch
200 insulation
11
13
15
30
50
61 main switch 62 high voltage battery
70 external voltage module 71 fixed voltage source
72 third switch 73 fourth switch.
Detailed Description
To explain the technical contents, structural features, and objects and effects of the invention in detail, the following description is given in conjunction with the accompanying drawings.
It should be understood that in the present specification, connection means electrical connection, and corresponds to a state in which current or voltage can be supplied or transmitted. Therefore, the connection does not necessarily have to be a direct connection, and a state of indirect connection through a wiring, a resistor, or the like so that current or voltage can be supplied or transmitted is also included in the category of the connection state.
It should be understood that in the present description, the switch may be an electronic component such as a MOSFET, BTJ, gyristor, etc. or a device or component that otherwise exhibits an off or on state, such as a mechanical switch, relay, electromagnetic contactor, etc. and the like.
As shown in fig. 1, a typical
As shown in fig. 5, the insulation
The detecting
The
The calculating
The calculating
The battery
The battery
The
As shown in fig. 6, some of the elements are omitted and not shown, but the first embodiment of the invention is intended to express the arrangement of each fixed resistor in the
The
As shown in fig. 7, when the
As shown in fig. 8, when the
As shown in fig. 9, when the
When the second voltage Vpack, the fourth voltage Vn and the sixth voltage Vn ' are obtained, the calculating
The calculating
When the
when the
bringing (a) into (B) and after finishing adjustment obtaining:
a low potential insulation resistance Rn expression:
and a high potential insulation resistance Rp formula:
the two operation expressions are formed by the first functionMWith each said fixed resistance, due to said first functionMThe voltages Vn, Vp, Vn 'and Vp' are calculated, and each of the fixed resistors is also known when designing the
As shown in fig. 10, some of the components are omitted and not shown in the figure, but the second embodiment of the present invention is intended to express the arrangement of each fixed resistor in the
The
As shown in fig. 11, when the
As shown in fig. 12, when the
As shown in fig. 13, when the
When the second voltage Vpack, the fourth voltage Vn and the sixth voltage Vn ' are obtained, the calculating
The calculating
When the
when the
bringing (C) into (D), and obtaining after finishing adjustments:
a low potential insulation resistance Rn expression:
and a high potential insulation resistance Rp formula:
the two operation expressions are formed by the first functionMFourth voltage Vn, seventh voltage Vp and each fixed resistor, due to the first functionMThe voltages Vn, Vp, Vn 'and Vp' are calculated, and each of the fixed resistors is also known when designing the
As shown in fig. 13, some of the components are omitted and not shown, but what is intended to be expressed by the third embodiment of the present invention is that an applied voltage module 70 is disposed in the insulation
The applied voltage module 70 includes a fixed voltage source 71, a third switch 72, and a fourth switch 73, the fixed voltage source 71 and the third switch 72 are connected in series between the
The voltage of the external voltage module 70 is smaller than the voltage of the high-voltage battery pack 62 in the
As described above, the insulation