Control of Variable Power Source-Coupled Electrolysers

Abstract

There is provided a water electrolysis system for hydrogen generation, wherein an electrolyser is coupled to a variable power source through a control device. The control device is configured to control at least one operating parameter of the electrolyser to increase its lifetime. The at least one operating parameter includes an electrical operating point (state) of the electrolyser, wherein the control device regulates an output power of the variable power source to match it to an electrical operating point (such as voltage and current) and input power to the electrolyser. The control device may comprise control units with modular configuration and hot-swap capabilities. The control device may comprise a state change smoothing method that produces operating parameter changes to bring the electrolyser from one state to another state.

What is claimed is: 
     
         1 . A control device for operatively connecting an electrolyser to a variable power source, the control device comprising:
 one or more energy storage devices;   a controller;   a sensor configured to sense output power of the variable power source and report a sensed power to the controller; and   an electrical power converter, configured to convert a first portion of the output power of the variable power source into an input power to an electrolyser stack, wherein the controller is configured to set the state of operation of the electrolyser stack and the first portion of the output power,   wherein the control device is configured to control at least one operating parameter change of the electrolyser stack.   
     
     
         2 . The control device of  claim 1 , wherein the controller is configured to change an operating parameter of the electrolyser continuously. 
     
     
         3 . The control device of  claim 1 , wherein the controller is configured to change an operating parameter of the electrolyser with a rate of change below a threshold rate of change. 
     
     
         4 . The control device of  claim 1 , wherein the controller is configured to change an operating parameter of the electrolyser with a second order rate of change below a threshold second order rate of change. 
     
     
         5 . The control device of  claim 1 , wherein the controller is configured to change an operating parameter of the electrolyser smoothly. 
     
     
         6 . A method comprising:
 receive a notice to perform a change an operating parameter of an electrolyser;   retrieve and store an initial state of the electrolyser;   apply the change to the electrolyser;   monitor a second operating parameter of the electrolyser;   compute a value of the monitored second operating parameter reflecting an expected response of the second operating parameter;   when the value indicates that the monitored second operating parameter complies with the expected response, store the initial state and the change in a permitted change table; and   when the value indicates that the monitored second operating parameter doesn't comply with the expected response, send a notification to decrease a second change at the initial state.   
     
     
         7 . A method comprising:
 receive a notice to perform a change an operating parameter of an electrolyser;   retrieve an initial state of the electrolyser;   estimate intermediate states and final state based on the change and the initial state;   for each state of the intermediate states and final state:
 retrieve a table of permitted changes for each of the intermediate states and the final state, and 
 compute a smoothed change between a previous state and the next state, and 
 apply the smoothed change to the electrolyser. 
   
     
     
         8 . The method of  claim 7 , further comprising actions to:
 monitor a second operating parameter of the electrolyser;   compute a value of the monitored second operating parameter reflecting an expected response of the second operating parameter;   when the value indicates that the monitored second operating parameter complies with the expected response, store the initial state and the change in a permitted change table; and   when the value indicates that the monitored second operating parameter doesn't comply with the expected response, send a notification to decrease a second change at the initial state.   
     
     
         9 . A device for operating an electrolyser connected to a variable power source, the device comprising a control circuit, where the control circuit is configured to apply a change to an operating parameter of the electrolyser, wherein the change comprises a continuous change in the operating parameter value, wherein the change comprises a rate of change less than a threshold rate of change, wherein the change comprises a second order rate of change less than a threshold second order rate of change. 
     
     
         10 . The device of  claim 9 , wherein the rate of change is continuous. 
     
     
         11 . The device of  claim 9 , wherein the control circuit comprises a controller or a processor and a repository connected to the control circuit, wherein the repository comprises controller or processor instructions configured to apply the change to the electrolyser. 
     
     
         12 . The device of  claim 9 , wherein the control circuit comprises active components and passive components configured to apply the change to the electrolyser. 
     
     
         13 . The device of  claim 9 , wherein the control circuit comprises passive components configured to apply the change to the electrolyser. 
     
     
         14 . The device of  claim 13 , wherein the passive components comprise an inductor or a capacitor. 
     
     
         15 . The device of  claim 13 , wherein the passive components are in series between the variable power source and the electrolyser. 
     
     
         16 . The device of  claim 13 , wherein the passive components are in parallel between the variable power source and the electrolyser. 
     
     
         17 . The device of  claim 9 , wherein the change comprises a voltage-controlled change. 
     
     
         18 . The device of  claim 9 , wherein the change comprises a current-controlled change. 
     
     
         19 . The device of  claim 9 , wherein the change, at least in part, follows at least part of a linear function, a parabolic function, a circular function, an elliptical function, a sigmoidal function, a logistical function, a hyperbolic function, an exponential function, a spline function, a polynomial function, or a quadratic function. 
     
     
         20 . The device of  claim 9 , wherein the change comprises steps, wherein the steps are determined by a digital to analog converter and an amplification circuit of a power converter, wherein the device comprises the digital to analog converter, the amplification circuit, and the power converter.