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KR-20260062549-A - VOLTAGE MONITORING APPARATUS FOR FUEL CELL STACK AND POWER SUPPLY METHOD THEREOF

KR20260062549AKR 20260062549 AKR20260062549 AKR 20260062549AKR-20260062549-A

Abstract

A voltage monitoring device for a fuel cell stack according to a preferred embodiment of the present invention includes a control unit that controls the supply of power used for monitoring a fuel cell stack, a high-side driving unit that outputs a pull-up power by the control unit, a low-side driving unit that outputs a pull-down power by the control unit, and a plurality of cell monitoring units that are individually connected to each cell of the fuel cell stack and monitor the voltage of each cell of the fuel cell stack when the pull-up power and the pull-down power are supplied.

Inventors

  • 김성호

Assignees

  • 주식회사 현대케피코

Dates

Publication Date
20260507
Application Date
20241029

Claims (14)

  1. A control unit that controls the supply of power used for monitoring a fuel cell stack; A high-side drive unit that outputs pull-up power by the above-mentioned control unit; A low-side drive unit that outputs pull-down power by the above-mentioned control unit; and A plurality of cell monitoring units individually connected to each cell of the fuel cell stack, and monitoring the voltage of each cell of the fuel cell stack when the pull-up power and the pull-down power are supplied; Voltage monitoring device for a fuel cell stack including
  2. In Article 1, A first converter that measures the output terminal voltage of the high-side driver connected to a pull-up resistor connected to a source power supply; A diagnostic switch provided between the pull-up resistor and the pull-down resistor connected to ground; A second converter for measuring the output terminal voltage of the low-side driver connected to the pull-down resistor; and A diagnostic unit that diagnoses whether there is a fault at the output terminal of the high-side driving unit and the low-side driving unit using the respective voltages of the first converter and the second converter; A voltage monitoring device for a fuel cell stack characterized by further including
  3. In Article 2, Each of the above plurality of cell monitoring units is, A voltage monitoring device for a fuel cell stack characterized by having a connecting resistor connecting the output terminals of the high-side driving unit and the low-side driving unit.
  4. In Paragraph 3, The above diagnostic unit is, A voltage monitoring device for a fuel cell stack characterized by, when operating in a fault diagnosis mode, performing turn-off control of the diagnostic switch, calculating a normal voltage value according to a plurality of pre-prepared calculation formulas based on the source power, the pull-up resistor, the pull-down resistor, and the connection resistor, and diagnosing a normal state based on whether the voltages of the first converter and the second converter match the normal voltage value.
  5. In Article 4, The above diagnostic unit is, A voltage monitoring device for a fuel cell stack characterized by calculating a plurality of fault voltage values according to a plurality of calculation formulas when the voltages of the first converter and the second converter do not match the normal voltage value, and diagnosing the type of fault at each output terminal of the high-side drive unit and the low-side drive unit based on the plurality of fault voltage values.
  6. In Article 5, The above diagnostic unit is, A voltage monitoring device for a fuel cell stack characterized by diagnosing a ground short circuit or an internal open circuit of each of the plurality of cell monitoring units depending on whether the voltage of each of the first converter and the second converter matches the low level voltage, the high level voltage, or the plurality of fault voltage values.
  7. In Article 6, The above diagnostic unit is, A voltage monitoring device for a fuel cell stack characterized by controlling the diagnostic switch to ON when the ground short circuit and each internal open circuit of the plurality of cell monitoring units are not diagnosed, and diagnosing a battery short circuit or an internal open circuit on the control unit side depending on whether the voltage of each of the first converter and the second converter matches at least one fault voltage value among the plurality of fault voltage values.
  8. A power supply method for a voltage monitoring device for a fuel cell stack, comprising a control unit for controlling a power supply for monitoring a fuel cell stack, a high-side driving unit connected to a pull-up resistor, a low-side driving unit connected to a pull-down resistor, and a plurality of cell monitoring units individually connected to each cell of the fuel cell stack, A diagnostic mode operation step in which the control unit operates in a fault diagnosis mode for diagnosing a fault at the output terminals of the high-side drive unit and the low-side drive unit; and A power supply control step in which the control unit supplies power to the plurality of cell monitoring units by controlling the high-side drive unit and the low-side drive unit to turn on, respectively, when each output terminal of the high-side drive unit and the low-side drive unit is normal; A power supply method for a voltage monitoring device for a fuel cell stack including
  9. In Article 8, Prior to the power supply control step above, the diagnostic unit performs a diagnostic switch control step in which it controls the turn-off of a diagnostic switch provided between the pull-up resistor and the pull-down resistor; The above diagnostic unit determines whether the voltage of a first converter connected to the output terminal of the high-side driving unit is normal or not; and The above diagnostic unit includes a second voltage determination step for determining whether the voltage of a second converter connected to the output terminal of the low-side driving unit is normal; A power supply method for a voltage monitoring device for a fuel cell stack, characterized by further including
  10. In Article 9, After the above first voltage determination step, the diagnostic unit, A high-side fault diagnosis step for diagnosing a fault type at the output terminal of the high-side driving unit when the voltage of the first converter does not correspond to a normal voltage value calculated according to a plurality of pre-prepared calculation formulas; and After the second voltage determination step, the diagnostic unit performs a low-side fault diagnosis step in which, if the voltage of the second converter does not correspond to the normal voltage value, the diagnostic unit diagnoses the fault type of the output terminal of the low-side driving unit; A power supply method for a voltage monitoring device for a fuel cell stack, characterized by further including
  11. In Article 10, The above high-side fault diagnosis step is, The above diagnostic unit includes a ground short circuit diagnosis step in which the voltage of the first converter is diagnosed as a ground short circuit fault when the voltage is at a low level; A disconnection diagnosis step in which the above-mentioned diagnostic unit diagnoses each of the plurality of cell monitoring units as an internal disconnection fault when the voltage of the first converter corresponds to at least one fault voltage value among the plurality of fault voltage values calculated according to the plurality of calculation formulas; and The diagnostic unit comprises a diagnostic switch control step that performs turn-on control of the diagnostic switch when the voltage of the first converter is a high level voltage; A power supply method for a voltage monitoring device for a fuel cell stack, characterized by including
  12. In Article 11, The above high-side fault diagnosis step is, A control-side open-circuit diagnosis step in which the diagnostic unit diagnoses an internal open-circuit fault on the control unit side when the voltage of the first converter corresponds to at least one other fault voltage value among the plurality of fault voltage values while the diagnostic switch is turned on; and The above diagnostic unit includes a battery short-circuit diagnosis step in which, when the voltage of the first converter in the turned-on state of the diagnostic switch does not correspond to at least one other fault voltage value among the plurality of fault voltage values, the diagnosis is made of a battery short-circuit fault; A power supply method for a voltage monitoring device for a fuel cell stack, characterized by further including
  13. In Article 10, The above low-side fault diagnosis step is, The above diagnostic unit includes a ground short circuit diagnosis step in which the voltage of the second converter is at a high level and is diagnosed as a ground short circuit fault; A disconnection diagnosis step in which the above-mentioned diagnostic unit diagnoses each of the plurality of cell monitoring units as an internal disconnection fault when the voltage of the second converter corresponds to at least one fault voltage value among the plurality of fault voltage values calculated according to the plurality of calculation formulas; and The diagnostic unit comprises a diagnostic switch control step that performs turn-on control of the diagnostic switch when the voltage of the second converter is a low level voltage; A power supply method for a voltage monitoring device for a fuel cell stack, characterized by including
  14. In Article 13, The above low-side fault diagnosis step is, A control-side open-circuit diagnosis step in which the above-described diagnostic unit diagnoses an internal open-circuit fault on the control unit side when the voltage of the second converter corresponds to at least one other fault voltage value among the plurality of fault voltage values while the above-described diagnostic switch is turned on; and The above diagnostic unit includes a battery short-circuit diagnosis step in which, when the voltage of the second converter in the turned-on state of the diagnostic switch does not correspond to at least one other fault voltage value among the plurality of fault voltage values, the diagnosis is made of a battery short-circuit fault; A power supply method for a voltage monitoring device for a fuel cell stack, characterized by further including

Description

Voltage monitoring apparatus for fuel cell stack and power supply method thereof The present invention relates to a voltage monitoring device for a fuel cell stack and a power supply method thereof. Fuel Cell Vehicles (FCVs) serve as an alternative to electric vehicles by generating electricity through the chemical reaction of hydrogen and oxygen, which is then used to power the vehicle. Fuel cell vehicles possess eco-friendly characteristics, emitting no exhaust gases while driving and only water. Furthermore, they can compensate for the shortcomings of electric vehicles by offering short hydrogen fuel charging times and long driving ranges. A fuel cell vehicle is composed of a fuel cell stack, a hydrogen storage tank, a power converter, and a drive motor. The fuel cell stack is a core device that generates electricity through a chemical reaction between hydrogen and oxygen, and the generated electricity is supplied to the vehicle's drive motor to move the vehicle. A fuel cell stack is a structure in which multiple unit cells are connected in series, and the voltages generated from each cell are combined to form the total voltage of the stack. The performance of a fuel cell stack depends on the condition of each cell; if the voltage of an individual cell drops abnormally low (or rises) or the cell is damaged, it can lead not only to a degradation of the overall stack's performance but also to system failure. Therefore, technology for monitoring the voltage of each cell in real time is essential to maintain the reliability and efficiency of the fuel cell stack. Conventional fuel cell stack voltage monitoring systems primarily measured the voltage of the entire stack, but they had limitations in detecting changes in the state of individual cells. Recently, fuel cell stack voltage monitoring systems are being manufactured in a manner that individually monitors the voltage of each cell in a fuel cell stack and detects voltage fluctuations in real time to quickly identify abnormal conditions. However, in the case of a Fuel-cell stack voltage monitor (FSVM) where a cell monitoring unit for monitoring the cell voltage of a fuel cell stack is located on the control board, there is a problem in that the system configuration becomes complex due to the large number of connector pins for connecting to individual cells of the fuel cell stack. FIG. 1 is a schematic circuit diagram of a voltage monitoring device for a fuel cell stack according to a preferred embodiment of the present invention. FIG. 2 is a flowchart of a power supply method for a voltage monitoring device for a fuel cell stack according to a preferred embodiment of the present invention. Figure 3 is a flowchart of the high-side fault diagnosis step of Figure 2. Figure 4 is a flowchart of the low-side fault diagnosis step of Figure 2. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. First, it should be noted that in assigning reference numerals to the components of each drawing, the same components are given the same reference numeral whenever possible, even if they are shown in different drawings. Furthermore, while preferred embodiments of the present invention will be described below, the technical concept of the present invention is not limited thereto and can be modified and implemented in various ways by those skilled in the art. FIG. 1 is a schematic circuit diagram of a voltage monitoring device for a fuel cell stack according to a preferred embodiment of the present invention. Referring to FIG. 1, a voltage monitoring device (100) for a fuel cell stack according to a preferred embodiment of the present invention is characterized in that a plurality of cell monitoring units for measuring the cell voltage of a fuel cell stack are configured to be separated from a control board and directly connected to the fuel cell stack. A voltage monitoring device (100) for a fuel cell stack according to a preferred embodiment of the present invention may include a control unit (110), a high-side driving unit (120), a low-side driving unit (130), a diagnostic unit (140), and a plurality of cell monitoring units (150). The control unit (110) can control the high-side drive unit (120) and the low-side drive unit (130) to supply power for the operation of a plurality of cell monitoring units (150). The high-side drive unit (120) can deliver pull-up power to a plurality of cell monitoring units (150) through a first output port (P1). The first output port (P1) can be electrically connected to each of the plurality of cell monitoring units (150). The low-side drive unit (130) can deliver pull-down power to a plurality of cell monitoring units (150) through a second output port (P2). The second output port (P2) can be electrically connected to each of the plurality of cell monitoring units (150). The diagnostic unit (140) can diagnose the fault condition of the first output port (P1) a