Pilot signal detection and indication unit and electric vehicle charging system including the same

Patent metadata

Field	Value
Publication number	US-10953762-B2
Application number	US-202016854988-A
Country	US
Kind code	B2
Filing date	Apr 22, 2020
Priority date	Dec 20, 2016
Publication date	Mar 23, 2021
Grant date	Mar 23, 2021

Abstract

A pilot signal detection and indication unit includes a pilot signal scaling unit structured to generate a scaled pilot signal by shifting a pilot signal using a bias voltage and scaling down the pilot signal, a pilot signal duty cycle comparator unit structured to generate a limited pilot signal that has a fixed peak voltage and a duty cycle that is equivalent to the duty cycle of the pilot signal, a processing unit structured to determine a voltage value and the duty cycle value of the pilot signal from the scaled pilot signal and the limited pilot signal, and to generate an indication signal based on the determined voltage value and duty cycle value, and an indication unit having a number of indicators and being structured to activate selected ones of the number of indicators based on the indication signal.

First claim

What is claimed is:

1. A pilot signal detection unit for use with an electric vehicle charging system having a pilot signal with a voltage value and a duty cycle, the pilot signal detection and indication unit comprising:
a pilot signal scaling unit structured to generate a scaled pilot signal by shifting the pilot signal and scaling down the pilot signal;
a pilot signal duty cycle comparator unit structured to generate a limited pilot signal that has a fixed peak voltage and a duty cycle that is equivalent to the duty cycle of the pilot signal; and
a processing unit structured to determine a voltage value and the duty cycle of the pilot signal from the scaled pilot signal and the limited pilot signal and to generate an indication signal based on the determined voltage value and duty cycle.

2. The pilot signal detection unit of claim 1 , wherein a voltage value of the scaled pilot signal is linearly related to the voltage value of the pilot signal.

3. The pilot signal detection unit of claim 2 , wherein the voltage value of the pilot signal has a range of −12V to 12V and the voltage value of the scaled pilot signal has a range of 0V to 3.3V.

4. The pilot signal detection unit of claim 1 , wherein the pilot signal scaling unit is structured to shift the pilot signal such that the scaled pilot signal is greater than or equal to 0V when the pilot signal is −12V.

5. The pilot signal detection unit of claim 1 , further comprising:
a bias voltage unit structured to generate a bias voltage using a supply voltage, and
wherein the pilot signal scaling unit is structured to shift the pilot signal using the bias voltage.

6. The pilot signal detection unit of claim 5 , wherein a maximum voltage value of the scaled pilot signal and the fixed peak voltage of the limited pilot signal are equal to a voltage value of the supply voltage.

7. The pilot signal detection unit of claim 6 , wherein the bias voltage unit is structured to generate a bias voltage whose voltage value is one half of the voltage value of the supply voltage.

8. The pilot signal detection unit of claim 5 , wherein the bias voltage unit includes two resistors arranged as a voltage divider and is structured to divide the supply voltage to generate the bias voltage.

9. The pilot signal detection unit of claim 1 , wherein the pilot signal scaling unit includes:
two resistors arranged as a voltage divider to divide a difference in voltage between the pilot signal and the bias voltage; and
a voltage follower circuit electrically connected to an output of the voltage divider.

10. The pilot signal detection unit of claim 9 , wherein the voltage divider is structured such that when the voltage value of the pilot signal is 12V the output of the voltage divider is 3.3V.

11. The pilot signal detection unit of claim 1 , wherein the pilot duty cycle comparator circuit is a comparator circuit structured to set the voltage value of the limited pilot signal to the fixed peak voltage when the voltage value of the pilot signal is greater than about 2V and to set the voltage value of the limited pilot signal to 0V when the voltage value of the pilot signal is less than about 2V.

12. The pilot signal detection unit of claim 11 , wherein the fixed peak voltage value is 3.3V.

13. The pilot signal detection unit of claim 11 , wherein the pilot duty cycle comparator circuit is structured to provide hysteresis.

14. The pilot signal detection unit of claim 1 , wherein the indication signal is selected from a plurality of distinct indication signals by the processing unit based on the determined voltage value and duty cycle value.

15. The pilot signal detection unit of claim 14 , wherein each of the plurality of distinct indication signals correspond to a particular status or charging capacity of the electric vehicle charging system.

16. The pilot signal detection unit of claim 1 , further comprising:
a power supply structured to receive a first voltage and to convert the first voltage to the supply voltage, wherein the supply voltage is less than the first voltage.

17. The pilot signal detection unit of claim 16 , wherein the first voltage is 12V and the supply voltage is 3.3V.

18. The pilot signal detection unit of claim 1 , further comprising:
an indication unit having a number of indicators and being structured to activate selected ones of the number of indicators based on the indication signal.

19. An electric vehicle charging system comprising:
an electric vehicle;
electric vehicle supply equipment structured to provide power to charge the electric vehicle and to generate a pilot signal having a voltage value and a duty cycle value; and
a connector structured to electrically connect the electric vehicle supply equipment to the electric vehicle, the connector including a pilot detection circuit comprising:
a pilot signal scaling unit structured to generate a scaled pilot signal by shifting the pilot signal and scaling down the pilot signal;
a pilot signal duty cycle comparator unit structured to generate a limited pilot signal that has a fixed peak voltage and a duty cycle that is equivalent to the duty cycle of the pilot signal; and
a processing unit structured to determine a voltage value and the duty cycle of the pilot signal from the scaled pilot signal and the limited pilot signal and to generate an indication signal based on the determined voltage value and duty cycle.

20. The electric vehicle charging system of claim 19 , wherein a voltage value of the scaled pilot signal is linearly related to the voltage value of the pilot signal.

21. The electric vehicle charging system of claim 19 , wherein the indication signal is selected from a plurality of distinct indication signals by the processing unit based on the determined voltage value and duty cycle value, and
wherein each of the plurality of distinct indication signals correspond to a particular status or charging capacity of the electric vehicle charging system.

Assignees

• Eaton Intelligent Power Ltd

Inventors

• Yang Andrew
• Xiong Tom
• Zhang Jerry
• Du Lily
• Zhang Harry

Classifications

• Y02T10/7072

  Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors · CPC title

• Y02T10/70

  Energy storage systems for electromobility, e.g. batteries · CPC title

• Y02T90/16

  Information or communication technologies improving the operation of electric vehicles · CPC title

• Y02T90/12

  Electric charging stations · CPC title

• Y02T90/14

  Plug-in electric vehicles · CPC title