Magnetic High Voltage Interlock Loop (HVIL) For Variable Frequency Drives In Transport Applications

Abstract

A magnetic HVIL system for a drive in a transport application includes a Hall effect sensor within at least one housing of the drive that includes terminals and a removable cover. The removable cover includes a magnet having a magnetic field that is detectable by the Hall effect sensor when the removable cover is installed on the housing. The magnetic field of the magnet is not detectable by the Hall effect sensor when the removable cover is removed from the housing. The magnet HVIL system is configured to be operable to enable active operation of the drive when the Hall effect sensor detects the magnetic field of the magnet and is in a closed circuit condition and disable operation of the drive when the Hall effect sensor does not detect the magnetic field of the magnet and is in an open circuit condition.

What is claimed is: 
     
         1 . A magnetic high voltage interlock loop (HVIL) system for a drive of a transport application, the magnetic HVIL system comprising:
 a first housing that includes input terminals and a first removable cover;   a first Hall effect sensor within the first housing;   a first magnet installed on the first removable cover such that a magnetic field of the first magnet is detectable by the first Hall effect sensor when the first removable cover is installed on the first housing and such that the magnetic field of the first magnet is not detectable by the first Hall effect sensor when the first removable cover is removed from the first housing;   a second housing that includes output terminals and a second removable cover;   a second Hall effect sensor within second first housing;   a second magnet installed on the second removable cover such that a magnetic field of the second magnet is detectable by the second Hall effect sensor when the second removable cover is installed on the second housing and such that the magnetic field of the second magnet is not detectable by the second Hall effect sensor when the second removable cover is removed from the second housing;   
       wherein the magnetic HVIL system is configured such that:
 for a first VDC input, the input terminals of the first housing and the output terminals of the second housing are disabled until the first and second removable covers are installed on the respective first and second housings and the magnetic fields of the first and second magnets are detected by the respective first and second Hall effect sensors; and 
 for a second VDC input, the input terminals of the first housing are not disabled but the output terminals of the second housing are disabled until the second removable cover is installed on the second housing and the magnetic field of the second magnet is detected by the second Hall effect sensor. 
 
     
     
         2 . The magnetic HVIL system of  claim 1 , wherein the magnetic HVIL system is configured such that:
 for a 650 VDC input, the input terminals of the first housing and the output terminals of the second housing are disabled until the first and second removable covers are installed on the respective first and second housings and the magnetic fields of the first and second magnets are detected by the respective first and second Hall effect sensors; and   for a 48 VDC input, the input terminals of the first housing are not disabled but the output terminals of the second housing are disabled until the second removable cover is installed on the second housing and the magnetic field of the second magnet is detected by the second Hall effect sensor.   
     
     
         3 . The magnetic HVIL system of  claim 1 , wherein:
 the first VDC input is higher than the second VDC input; and   the drive comprises a variable frequency drive.   
     
     
         4 . The magnetic HVIL system of  claim 1 , wherein:
 the first removable cover includes a first inwardly protruding portion that projects into an interior of the first housing when the first removable cover is installed on the first housing; and   the first magnet is located at a distal end of the first inwardly protruding portion of the first removable cover;   the second removable cover includes a second inwardly protruding portion that projects into an interior of the second housing when the second removable cover is installed on the second housing; and   the second magnet is located at a distal end of the second inwardly protruding portion of the second removable cover.   
     
     
         5 . The magnetic HVIL system of  claim 1 , wherein:
 the first housing comprises a first terminal wiring housing for input power; and   the second housing comprises a second terminal wiring housing for output power.   
     
     
         6 . The magnetic HVIL system of  claim 1 , wherein:
 the first housing comprises an input terminal box of the drive; and   the second housing comprises an output terminal box of the drive.   
     
     
         7 . The magnetic HVIL system of  claim 1 , wherein:
 the first removable cover includes a lower portion configured such that the input terminals within the first housing remain covered by the first removable cover and are inaccessible until the first magnet is out of a detection range of the first Hall effect sensor; and   the second removable cover includes a lower portion configured such that the output terminals within the second housing remain covered by the second removable cover and are inaccessible until the second magnet is out of a detection range of the second Hall effect sensor.   
     
     
         8 . The magnetic HVIL system of  claim 1 , wherein the magnetic HVIL system includes at least one control in communication with the first and second Hall effect sensors that is operable for:
 enabling the input terminals of the first housing and the output terminals of the second housing for the first VDC input when the magnetic fields of the first and second magnets are detected by the respective first and second Hall effect sensors and the first and second Hall effect sensors are in a closed circuit condition;   disabling the input terminals of the first housing and the output terminals of the second housing for the first VDC input when the magnetic fields of the first and second magnets are not detected by the respective first and second Hall effect sensors and the first and second Hall effect sensors are in an open circuit condition; and   only disabling the output terminal of the second housing for the second VDC input when the magnetic field of the second magnet is not detected by the second Hall effect sensor and the second Hall effect sensor is in an open circuit condition.   
     
     
         9 . A variable frequency drive comprising the magnetic HVIL system of  claim 1 . 
     
     
         10 . The variable frequency drive of  claim 9 , wherein the variable frequency drive is configured such that the first and second removable covers must both be installed on the respective first and second terminal wire housings to enable the variable frequency drive for the first VDC input but only the second removable cover must be installed on the second terminal wire housing to enable the variable frequency drive for the second VDC input. 
     
     
         11 . A variable frequency drive comprising the magnetic HVIL system of  claim 1 , wherein the output terminals of the second housing are configured to enable the variable frequency drive to charge input batteries of a vehicle when the vehicle is not running and is externally being charged from an external power source. 
     
     
         12 . A variable frequency drive comprising the magnetic HVIL system of  claim 1 , wherein the input terminals of the first housing are connectible with a DC input power supply for the variable frequency drive. 
     
     
         13 . A variable frequency drive comprising the magnetic HVIL system of  claim 1 , wherein the output terminals of the second housing are connectible with a compressor to provide AC input to the compressor. 
     
     
         14 . A vehicle comprising a variable frequency drive including the magnetic HVIL system of  claim 1 , wherein:
 the vehicle is an electric vehicle, a hybrid vehicle, or a mobile refrigeration vehicle including an internal combustion engine; and/or   the variable frequency drive is configured to have an input voltage of 48 VDC, 350 VDC, or 650 VDC and/or an output voltage of at least 60 VDC.   
     
     
         15 . A drive for a transport application comprising a magnetic high voltage interlock loop (HVIL) system that comprises:
 at least one Hall effect sensor within at least one housing that includes terminals and a removable cover;   the removable cover includes a magnet having a magnetic field that is detectable by the Hall effect sensor when the removable cover is installed on the housing, the magnetic field of the magnet is not detectable by the Hall effect sensor when the removable cover is removed from the housing;   whereby the magnetic HVIL system is configured to be operable to:
 enable active operation of the drive when the Hall effect sensor detects the magnetic field of the magnet and is in a closed circuit condition; and 
 disable operation of drive when the Hall effect sensor does not detect the magnetic field of the magnet and is in an open circuit condition; 
   
       wherein:
 the terminals are configured to enable the drive to charge input batteries of a vehicle when the vehicle is not running and is externally being charged from an external power source; and/or 
 the terminals comprise input terminals connectible with a DC input power supply for the drive; and/or 
 the terminals comprise output terminals connectible with a compressor to provide AC input to the compressor. 
 
     
     
         16 . The drive of  claim 15 , wherein:
 the drive comprises a variable frequency drive; and   the terminals comprise shore power positive and negative terminals configured to enable the variable frequency drive to charge input batteries of a vehicle when the vehicle is not running and is externally being charged from an external power source.   
     
     
         17 . The drive of  claim 15 , wherein:
 the drive comprises a variable frequency drive; and   the terminals comprise input terminals connectible with a DC input power supply for the variable frequency drive.   
     
     
         18 . The drive of  claim 15 , wherein:
 the drive comprises a variable frequency drive; and   the terminals comprise output terminals connectible with a compressor to provide AC input to the compressor.   
     
     
         19 . The drive of  claim 15 , wherein:
 the removable cover comprises a first removable cover and a second removable cover;   the at least one housing comprises a first housing including input terminals and the first removable cover, and a second housing including output terminals and the second removable cover;   the Hall effect sensor comprises a first Hall effect sensor within the first housing, and a second Hall effect sensor within the second housing;   the magnet comprises:
 a first magnet installed on the first removable cover such that a magnetic field of the first magnet is detectable by the first Hall effect sensor when the first removable cover is installed on the first housing and such that the magnetic field of the first magnet is not detectable by the first Hall effect sensor when the first removable cover is removed from the first housing; and 
 a second magnet installed on the second removable cover such that a magnetic field of the second magnet is detectable by the second Hall effect sensor when the second removable cover is installed on the second housing and such that the magnetic field of the second magnet is not detectable by the second Hall effect sensor when the second removable cover is removed from the second housing. 
   
     
     
         20 . The drive of  claim 19 , wherein the drive is configured such that:
 for a first VDC input, the input terminals of the first housing and the output terminals of the second housing are disabled until the first and second removable covers are installed on the respective first and second housings such that the magnetic fields of the first and second magnets are detected by the respective first and second Hall effect sensors and the first and second Hall effect sensors are in a closed circuit condition; and   for a second VDC input, the input terminals of the first housing are not disabled but the output terminals of the second housing are disabled until the second removable cover is installed on the second housing such that the magnetic field of the second magnet is detected by the second Hall effect sensor and the second Hall effect sensor is in a closed circuit condition.   
     
     
         21 . A vehicle comprising the drive of  claim 15 , wherein:
 the vehicle is an electric vehicle, a hybrid vehicle, or a mobile refrigeration vehicle including an internal combustion engine; and/or   the drive comprises a variable frequency drive configured to have an input voltage of 48 VDC, 350 VDC, or 650 VDC and/or an output voltage of at least 60 VDC.