System and method for limiting over-voltage in power supply system

Patent metadata

Field	Value
Publication number	US-9938115-B2
Application number	US-201315104810-A
Country	US
Kind code	B2
Filing date	Dec 19, 2013
Priority date	Dec 19, 2013
Publication date	Apr 10, 2018
Grant date	Apr 10, 2018

Abstract

A system and method for providing a protective extra low voltage power supply in an elevator system ( 2 ) is disclosed. The power supply system ( 10 ) may include a switch mode power supply ( 12 ) configured to provide an output voltage, a first voltage monitor ( 18 ) and a second voltage monitor ( 20 ). Each of the first voltage monitor ( 18 ) and the second voltage monitor ( 20 ) may be configured to receive the output voltage and determine an over-voltage condition at the switch mode power supply ( 12 ).

First claim

What is claimed is:

1. An elevator system, comprising:
an elevator car; and
a power supply system configured to supply protective extra low voltage to the elevator car, the power supply system having a switch mode power supply configured to provide an output voltage to the elevator car, a first voltage monitor and a second voltage monitor, the first and the second voltage monitors configured to detect an over-voltage condition at the switch mode power supply and turn the switch mode power supply off if the over-voltage condition is detected.

2. The elevator system of claim 1 , wherein the first voltage monitor and the second voltage monitor compare the output voltage against a reference voltage to determine the over-voltage condition at the switch mode power supply.

3. The elevator system of claim 1 , wherein one of the first voltage monitor and the second voltage monitor is implemented using a comparator and the other one of the first voltage monitor and the second voltage monitor is implemented using a micro control unit.

4. The elevator system of claim 3 , wherein the first voltage monitor is implemented using the comparator and the second voltage monitor is implemented using the micro control unit.

5. The elevator system of claim 1 , wherein the first voltage monitor includes a comparator configured to receive the output voltage and a reference voltage and output a signal indicating the higher one of the output voltage and the reference voltage.

6. The elevator system of claim 1 , wherein the second voltage monitor includes a comparator configured to compare the output voltage against a reference voltage and, output a signal indicating the higher one of the output voltage and the reference voltage.

7. The elevator system of claim 1 , wherein the first voltage monitor includes a micro control unit configured to compare the output voltage against a reference voltage and, output a signal indicating the higher one of the output voltage and the reference voltage.

8. The elevator system of claim 1 , wherein the second voltage monitor includes a micro control unit configured to compare the output voltage against a reference voltage and, output a signal indicating the higher one of the output voltage and the reference voltage.

9. The elevator system of claim 1 , wherein the first voltage monitor includes a test switch configured to input a test voltage into the first voltage monitor when the test switch is closed, the test voltage configured to simulate the over-voltage condition at the switch mode power supply.

10. The elevator system of claim 1 , wherein the second voltage monitor includes a test switch configured to input a test voltage into the second voltage monitor when the test switch is closed, the test voltage configured to simulate the over-voltage condition at the switch mode power supply.

11. The elevator system of claim 1 , wherein the switch mode power supply is connected to a main power supply, the switch mode power supply configured to convert power from the main power supply into the output voltage.

12. The elevator system of claim 1 , wherein the second voltage monitor provides a redundant switch off path to the switch mode power supply if the first voltage monitor malfunctions.

13. The elevator system of claim 1 , wherein the first voltage monitor and the second voltage monitor prevent the output voltage from going over approximately sixty volts of direct current.

Assignees

• Otis Elevator Co

Inventors

• Gewinner Juergen
• Herkel Peter

Classifications

• B66B1/28

  electrical (detecting excessive speed B66B5/04 {; control of electrical motor H02P}) · CPC title

• B66B5/0031 Primary

  for safety reasons · CPC title

• B66B1/30 Primary

  effective on driving gear {, e.g. acting on power electronics, on inverter or rectifier controlled motor} · CPC title

• G01R19/165

  Indicating that current or voltage is either above or below a predetermined value or within or outside a predetermined range of values · CPC title

• B66B1/3446

  Data transmission or communication within the control system · CPC title