Multiplex voltage measurement apparatus

• US 6,541,980 B2
• Filed: 04/10/2001
• Issued: 04/01/2003
• Est. Priority Date: 04/10/2000
• Status: Expired due to Term

• Current Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation), Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Maki, Ichiro
• Primary Examiner(s): Le, N.
• Assistant Examiner(s): LEROUX, ETIENNE PIERRE
• Application Number:
  US09/829,732
• Publication Number:
  US 20010035765A1
• Time in Patent Office: 721 Days
• Field of Search: 324/428, 324/433, 324/434, 324/435, 324/663, 324/426, 324/429, 324/149, 324/140.R, 320/116, 320/120, 320/136, 340/636, 340/661
• US Class Current: 324/426
• CPC Class Codes: G01R 19/16542 for batteries charge condition monitoring in G01R31/36
• CPC Class Codes: G01R 31/396 Acquisition or processing of data for testing or for monitoring individual cells or groups of cells within a battery

Abstract

A multiplex voltage measurement apparatus configured to detect the breakage of a line coupling a voltage detection terminal and an electric leakage detection circuit includes a multiplex voltage measurement section and an electric leakage detection circuit. The multiplex voltage measurement section is configured to measure the voltage of each of N serially connected voltage sources via (N+1) voltage detection terminals coupled to a capacitor. The electric leakage detection circuit is configured to measure an insulation impedance between the voltage sources and a chassis. A sample switch in the leakage detection circuit prevents the formation of a loop connecting the electric leakage detection circuit to the voltage measurement section in the event of a disconnection between a voltage detection terminal and the multiplex voltage measurement section, allowing the detection of such a disconnection.

Claims

1. A multiplex voltage measurement apparatus, comprising a multiplex voltage measurement section for measuring a voltage of each of N serially connected voltage sources and an electric leakage detection circuit for measuring an insulation impedance between the N voltage sources and a chassis,

the multiplex voltage measurement section induding,

(N+1) voltage detection terminals connected to the N voltage sources,

a first capacitor having a first terminal and a second terminal,

a first multiplexer for selectively connecting any of odd-numbered voltage detection terminals among the (N+1) voltage detection terminals to the first terminal of the first capacitor,

a second multiplexer for selectively connecting any of even-numbered voltage detection terminals among the (N+1) voltage detection terminals to the second terminal of the first capactor,

a voltage measurement circuit for measuring the voltage between the first terminal and the second terminal of the first capacitor,

a first sample switch for connecting the first terminal and the second terminal of the first capacitor to the voltage measurement circuit, and

a polarity correction circuit for changing the polarity of voltages of the N voltage sources such that the voltages of the odd-numbered voltage sources among the N voltage sources and the voltages of the even-numbered voltage sources among the N voltage sources have the same polarity,

wherein the multiplex voltage measurement section measures the voltages of the N voltage sources by repeating a process in which the first and second multiplexers select one of the N voltage sources, and the first and second multiplexers are opened while the first sample switch is closed, and

the electric leakage detection circuit including,

a second capacitor connected to an end terminal of the (N+1) voltage detection terminals,

a signal generator for supplying a signal through the second capacitor to the end terminal of the (N+1) voltage detection terminals,

a level comparison circuit for comparing a signal level of the signal generator and a signal level of the second capacitor, and

a second sample switch provided between the signal generator and the end terminal of the (N+1) voltage detection terminals.

2. A multiplex voltage measurement apparatus according to claim 1, wherein the second sample switch is provided between the second capacitor and the end terminal of the (N+1) voltage detection terminals.

3. A multiplex voltage measurement apparatus according to claim 1, wherein the second sample switch is provided between the second capacitor and the signal generator.

4. A multiplex voltage measurement apparatus according to claim 1, wherein the second sample switch is opened only when the multiplex voltage measurement circuit measures one of the N voltage sources which is located at the end terminal of the (N+1) voltage detection terminals.

5. A multiplex voltage measurement apparatus, comprising a multiplex voltage measurement section for measuring a voltage of each of N serially connected voltage sources and an electric leakage detection circuit for measuring an insulation impedance between the N voltage sources and a chassis,

the multiplex voltage measurement section including,

(N+1) voltage detection terminals connected to the N voltage sources,

a first capacitor having a first terminal and a second terminal,

a first multiplexer for selectively connecting any of odd-numbered voltage detection terminals among the (N+1) voltage detection terminals to the first terminal of the first capacitor,

a second multiplexer for selectively connecting any of even-numbered voltage detection terminals among the (N+1) voltage detection terminals to the second terminal of the first capacitor,

a voltage measurement circuit for measuring the voltage between the first terminal and the second terminal of the first capacitor,

a first sample switch for connecting the first terminal and the second terminal of the first capacitor to the voltage measurement circuit, and

a polarity correction circuit for changing the polarity of voltages of the N voltage sources such that the voltages of the odd-numbered voltage sources among the N voltage sources and the voltages of the even-numbered voltage sources among the N voltage sources have the same polarity,

wherein the multiplex voltage measurement section measures the voltages of the N voltage sources by repeating a process in which the first and second multiplexers select one of the N voltage sources, and the first and second multiplexers are opened while the first sample switch is closed, and

the electric leakage detection circuit including,

a second capacitor connected to an end terminal of the (N+1) voltage detection terminals,

a signal generator for supplying a signal through the second capacitor to the end terminal of the (N+1) voltage detection terminals,

a level comparison circuit for comparing a signal level of the signal generator and a signal level of the second capacitor, and

a second sample switch provided between the signal generator and the end terminal of the (N+1) voltage detection terminals, whereby an incorrect voltage is not measured by the voltage measurement circuit in the event of a disconnection in the multiplex voltage measurement circuit.