Battery power supply device characteristic measuring apparatus and measuring method

• US 5,955,885 A
• Filed: 07/24/1996
• Issued: 09/21/1999
• Est. Priority Date: 07/26/1995
• Status: Expired due to Fees

• Current Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Original Assignee: Canon Kabushiki Kaisha (Canon Inc.)
• Inventors: Kurokami, Seiji, Takehara, Nobuyoshi, Fukae, Kimitoshi
• Primary Examiner(s): Ballato, Josie
• Assistant Examiner(s): VALONE, THOMAS F
• Application Number:
  US08/685,540
• Time in Patent Office: 1,154 Days
• Field of Search: 324/426, 324/767, 324/404, 330/2, 371/20, 136/244, 136/243
• US Class Current: 324/426
• CPC Class Codes: G01R 31/40 Testing power supplies testing photovoltaic devices H02S50/10
• CPC Class Codes: H02S 50/10 Testing of PV devices, e.g. of PV modules or single PV cells testing of semiconductor devices during manufacturing H01L22/00
• CPC Class Codes: H02S 50/15 using optical means, e.g. using electroluminescence
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

In order to accurately and stably measure the output characteristics of a battery power supply device, especially, a large-scale solar cell module by an equipment that requires only a size and cost equivalent to those of an apparatus used for measuring a small-scale module, the light-receiving surface of the solar cell module is divided into areas each including a bypass diode, the output characteristics upon light illumination in units of divided areas are measured, the measured characteristics are synthesized, and the influence of bypass diode characteristics is subtracted from the synthesized characteristics, thereby calculating the output characteristics of the solar cell module.

Claims

1. A solar cell output characteristic measuring apparatus comprising:

voltage detection means for detecting an output voltage from a solar cell in which m (m≧

2) parallel blocks each including a photoelectric conversion element and a bypass diode connected in inverse-parallel to the photoelectric conversion element are connected in series with each other;

current detection means for detecting an output current from the solar cell;

operation point control means, connected to an output terminal of the solar cell, for changing an operation point of the solar cell upon measuring output characteristics of the solar cell;

light illumination means for illuminating the photoelectric conversion element in a portion of the solar cell upon measuring the output characteristics;

means for dividing the solar cell into n (2≦

n≦

m) areas each including at least one parallel block, and measuring output characteristics of the solar cell in units of areas by illuminating the photoelectric conversion element in one area by said light illumination means and shielding the photoelectric conversion elements in other (n-1) areas from light;

means for calculating output characteristics of the individual areas by synthesizing characteristics of the bypass diodes energized upon measuring the output characteristics in units of areas; and

means for calculating output characteristics of the entire solar cell by synthesizing the output characteristics of the individual areas calculated in units of areas.

2. A solar cell output characteristic measuring apparatus comprising:

voltage detection means for detecting an output voltage from a solar cell in which m (m≧

2) parallel blocks each including a photoelectric conversion element and a bypass diode connected in inverse-parallel to the photoelectric conversion element are connected in series with each other;

current detection means for detecting an output current from the solar cell;

operation point control means, connected to an output terminal of the solar cell, for changing an operation point of the solar cell upon measuring output characteristics of the solar cell;

light illumination means for illuminating the photoelectric conversion element in a portion of the solar cell upon measuring the output characteristics;

means for dividing the solar cell into n (2≦

n≦

m) areas each including at least one parallel block, and measuring output characteristics of the solar cell in units of areas by illuminating the photoelectric conversion element in one area by said light illumination means and shielding the photoelectric conversion elements in other (n-1) areas from light;

means for synthesizing the output characteristics in units of areas; and

means for calculating output characteristics of the entire solar cell by synthesizing the synthesized output characteristics and diode characteristics for a total number of bypass diodes energized upon measuring.

3. A solar cell output characteristic measuring apparatus comprising:

voltage detection means for detecting an output voltage from a solar cell in which m (m≧

2) parallel blocks each including a photoelectric conversion element and a bypass diode connected in inverse-parallel to the photoelectric conversion element are connected in series with each other;

current detection means for detecting an output current from the solar cell;

operation point control means, connected to an output terminal of the solar cell, for changing an operation point of the solar cell upon measuring output characteristics of the solar cell;

light illumination means for illuminating the photoelectric conversion element in a portion of the solar cell upon measuring the output characteristics;

means for dividing the solar cell into n (2≦

n≦

m) areas each including at least one parallel block, and measuring output characteristics of the solar cell in units of areas by illuminating the photoelectric conversion element in one area by said light illumination means and shielding the photoelectric conversion elements in other (n-1) areas from light;

means for measuring output characteristics of the solar cell by shielding all the photoelectric conversion elements from light; and

means for calculating output characteristics of the entire solar cell by synthesizing n output characteristics measured in units of areas and output characteristics corresponding to the (n-1) portions measured when all the photoelectric conversion elements are shielded from light.

4. A method for measuring characteristics of a solar cell module having a plurality of unit areas each having photoelectric conversion elements and bypass diodes connected in inverse-parallel relation with respective ones of said photoelectric conversion elements, comprising the steps of:

preliminarily measuring current-voltage characteristics of said bypass diodes;

selectively illuminating one of said unit areas and shielding the remaining unit areas;

measuring current-voltage characteristics of said solar cell module by changing an operation point of said solar cell module;

calculating current-voltage characteristics of the bypass diodes in the non-illuminated areas;

subtracting said current-voltage characteristics of the bypass diodes in the non-illuminated areas from the measured current-voltage characteristics of said solar cell module to obtain current-voltage characteristics of said single illuminated unit area; and

similarly obtaining current-voltage characteristics of other ones of the unit areas, and adding all the obtained current-voltage characteristics of the unit areas,

thereby obtaining current-voltage characteristics of the entire solar cell module.

5. A method for measuring characteristics of a solar cell module having a plurality of unit areas each having photoelectric conversion elements and bypass diodes connected in inverse-parallel relation with respective ones of said photoelectric conversion elements, comprising the steps of:

preliminarily measuring current-voltage characteristics of said bypass diodes;

selectively illuminating one of said unit areas and shielding the remaining unit areas;

measuring current-voltage characteristics of said solar cell module by changing an operation point of said solar cell module;

illuminating other ones of said unit areas individually, while shielding from light remaining unit areas, and measuring current-voltage characteristics of said solar cell module for each individual illumination;

summing all of the measured current-voltage characteristics of said solar cell module;

calculating total current-voltage characteristics of the bypass diodes in the non-illuminated areas; and

subtracting said total current-voltage characteristics of the bypass diodes in the non-illuminated areas from the sum of all the measured current-voltage characteristics of said solar cell module,

thereby obtaining current-voltage characteristics of the entire solar cell module.

6. A method for measuring characteristics of a solar cell module having n (n≧

2) unit areas each having photoelectric conversion elements and bypass diodes connected in inverse-parallel relation with respective ones of said photoelectric conversion elements, comprising the steps of;

selectively illuminating one of said unit areas and shielding the remaining unit areas;

measuring current-voltage characteristics of said solar cell module by changing an operation point of said solar cell module;

illuminating other ones of said unit areas individually, while shielding from light remaining unit areas, and measuring current-voltage characteristics of said solar cell module for each individual illumination;

summing all of the measured current-voltage characteristics of said solar cell module;

measuring total current-voltage characteristics of the bypass diodes by shielding the entire surface of the solar cell module;

calculating current-voltage characteristics of the bypass diodes corresponding to (n-1) areas; and

subtracting said current-voltage characteristics of the bypass diodes corresponding to (n-1) areas from the sum of all the measured current-voltage characteristics of said solar cell module,

thereby obtaining current-voltage characteristics of the entire solar cell module.