Electrolytic cell power supply device

Abstract

An electrolytic cell power supply device is provided, the electrolytic cell power supply device includes: a first converter configured to convert alternating current power supplied from a power system into direct current power; a storage element configured to store direct current power output from the first converter; a second converter configured to convert the direct current power stored in the storage element into other direct current power corresponding to the electrolytic cell, and supply the direct current power after the conversion between the anode and the cathode of the electrolytic cell; and a control device configured to control operations of the first and second converters, the control device includes a corrosion prevention operation mode In a power interruption of the power system, the corrosion prevention operation mode controlling the operation of the second converter to suppress a generation of a reverse current by supplying, to the electrolytic cell, a direct current power. Accordingly, an electrolytic cell power supply device that can suppress the generation of a reverse current with a simpler configuration is provided.

1 . An electrolytic cell power supply device causing an electrolytic cell to perform electrolysis by supplying direct current power between an anode and a cathode of the electrolytic cell, the electrolytic cell power supply device comprising:
 a first converter configured to convert alternating current power supplied from a power system into direct current power;   a storage element configured to store direct current power output from the first converter;   a second converter configured to
 convert the direct current power stored in the storage element into other direct current power corresponding to the electrolytic cell, and 
 supply the direct current power after the conversion between the anode and the cathode of the electrolytic cell; and 
   a control device configured to control operations of the first and second converters,   the control device including
 a normal operation mode when the power system is normal, the normal operation mode controlling the operations of the first and second converters to supply, to the electrolytic cell, direct current power for performing electrolysis based on the alternating current power supplied from the power system, and 
 a corrosion prevention operation mode in a power interruption of the power system, the corrosion prevention operation mode controlling the operation of the second converter to suppress a generation of a reverse current by supplying, to the electrolytic cell, a direct current power that is based on the direct current power stored in the storage element and is smaller than the direct current power supplied to the electrolytic cell in the normal operation mode, the reverse current being a current component flowing in an opposite direction of normal electrolysis inside the electrolytic cell. 
   
     
     
         2 . The electrolytic cell power supply device according to  claim 1 , wherein
 the control device stops the operation of the first converter in the corrosion prevention operation mode.   
     
     
         3 . The electrolytic cell power supply device according to  claim 1 , wherein
 the control device controls the operation of the first converter in the corrosion prevention operation mode to supply only reactive power to the power system based on the direct current power stored in the storage element.   
     
     
         4 . The electrolytic cell power supply device according to  claim 1 , wherein
 the control device gradually changes a magnitude of the direct current power supplied to the electrolytic cell when switching from the normal operation mode to the corrosion prevention operation mode and when switching from the corrosion prevention operation mode to the normal operation mode.   
     
     
         5 . The electrolytic cell power supply device according to  claim 1 , further comprising:
 an emergency generator configured to charge the storage element in the power interruption of the power system.   
     
     
         6 . The electrolytic cell power supply device according to  claim 5 , further comprising:
 a rectifier configured to perform an pre-charging of the storage element based on the alternating current power supplied from the power system,   the emergency generator being configured to charge the storage element via the rectifier by generating alternating current power and supplying the generated alternating current power to the rectifier,   
     
     
         7 . The electrolytic cell power supply device according to  claim 1 , further comprising:
 a first current sensor configured to detect a direct current supplied to the electrolytic cell from the second converter in the normal operation mode; and   a second current sensor configured to detect a direct current supplied to the electrolytic cell from the second converter in the corrosion prevention operation mode,   the control device controlling the operation of the second converter based on a detection result of the first current sensor in the normal operation mode, and controlling the operation of the second converter based on a detection result of the second current sensor in the corrosion prevention operation mode.   
     
     
         8 . The electrolytic cell power supply device according to  claim 1 , wherein
 the second converter includes a plurality of conversion circuits connected in parallel, and   the control device operates each of the plurality of conversion circuits in the normal operation mode, and operates only a portion of the plurality of conversion circuits in the corrosion prevention operation mode.   
     
     
         9 . The electrolytic cell power supply device according to  claim 8 , wherein
 each of the plurality of conversion circuits includes a switching element and converts direct current power by a switching of the switching element, and   the control device performs a control of shifting timing of the switching of the switching elements of the plurality of conversion circuits in the normal operation mode, and performs a control of setting switching frequencies of the switching elements of the portion of the plurality of conversion circuits in the corrosion prevention operation mode to be higher than switching frequencies of the switching elements of the plurality of conversion circuits in the normal operation mode.