Abstract:
A method and apparatus for receiving a selection of a first device under test. Connecting the first device under test to a load based at least on a closed high-side driver relay and a closed low-side driver relay for a first switch, from a plurality of devices under test. Closing at a first rate a high-side driver relay of a first switch based at least on the received selection. Closing at a second rate a low-side driver relay of the first switch based at least on the received selection, wherein the first rate and second rate are different.

Description:
STATEMENT OF GOVERNMENT INTEREST 
       [0001]    The United States Government has rights in this invention pursuant to Contract No. DE-AC02-06CH11357 between the United States Government and the UChicago Argonne, LLC, representing Argonne National Laboratory. 
     
    
     FIELD OF THE INVENTION 
       [0002]    This invention relates to a method of multiplexing battery cycler hardware. More specifically, this invention relates to novel multiplexing strategies for improving utilization of battery cycler hardware. 
       BACKGROUND OF THE INVENTION 
       [0003]    This section is intended to provide a background or context to the invention that is, inter alia, recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section. 
         [0004]    Battery cycling hardware is expensive hardware that has long lead times. Because battery testing can lead to long wait times, there is a need to share battery cycler hardware channels across multiple test batteries. Existing methods for sharing battery cycler hardware include manual operation of the battery cycler hardware involving disconnecting one battery and connecting another. However, manual operation of the battery cycler requires operators to switch the batteries at specific times. 
       SUMMARY 
       [0005]    The present invention addresses these problems and provides processes for automating switching to different test channels. In some embodiments methods for receiving a selection of a first device under test are presented. Connecting the first device under test to a load based at least on a closed high-side driver relay and a closed low-side driver relay for a first switch, from a plurality of devices under test. Closing at a first rate a high-side driver relay of a first switch based at least on the received selection. Closing at a second rate a low-side driver relay of the first switch based at least on the received selection, wherein the first rate and second rate are different. The load and power supply be a cycler or be separate components. 
         [0006]    In other embodiments, apparatus comprising a power supply, a load, and a plurality of switches is presented. Each switch in the apparatus comprising a high-side driver and a low side-driver, wherein the load and plurality of switches are part of a plurality of circuits. A first switch in the plurality of switches corresponds to a first circuit in the plurality of circuits, wherein the first switch is closed when the high-side driver relay and the low-side driver relay of the first switch are closed, wherein the high-side driver relay of the first switch is closed at a first rate based at least on a selection of the first circuit, wherein the low-side driver relay of the first switch is closed at a second rate based at least on the selection of the first circuit, wherein the first and second rates are different. The first circuit is completed based at least on the first switch being closed. 
         [0007]    These and other advantages and features of the invention, together with the organization and manner of operation thereof, will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, wherein like elements have like numerals throughout the several drawings described below. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a schematic showing a single relay channel in an illustrative embodiment. 
           [0009]      FIG. 2  shows a three to one cell multiplexed relay channel in an illustrative embodiment. 
           [0010]      FIG. 3  is a control timing chart in an illustrative embodiment. 
           [0011]      FIG. 4  is a schematic of a dual drive relay in an illustrative embodiment. 
           [0012]      FIGS. 5A and 5B  are schematics of a slow-filter clock and a fast-filter clock in an illustrative embodiment. 
           [0013]      FIG. 6  is a schematic of input signals for controlling the operation of the multiplexed relay channel in an illustrative embodiment. 
           [0014]      FIG. 7  is a schematic of safety logic for controlling operation of the multiplexed relay channel in an illustrative embodiment. 
           [0015]      FIGS. 8A-8D  are schematics of drive controllers for controlling contactor switches to different DUTs. 
           [0016]      FIGS. 9A-9D  are schematics of drive controllers for controlling V sense  switches to different DUTs. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0017]    In certain embodiments, the present invention provides improved methods for a single cycler setup to control and monitor multiple devices under test (DUT) through manual or automated switching between DUTs. The disclosed cycler multiplexes cycler channels using automated hardware systems with hardware or software control so that only one DUT is connected to the cycler. Additionally, the cycler can include hardware safety logic to prevent DUTs from interfering with one another. For example, if multiple DUTs attempt to connect, the hardware safety logic can disconnect all DUTs from the cycler. A DUT can be any electronic device including, but not limited to a battery or transistor. 
         [0018]      FIG. 1  is a schematic showing a single channel relay configuration in an illustrative embodiment. The single channel relay  100  connects a load and a power supply  104  to a DUT  106 . Power is supplied to the DUT  106  by closing connector relay  112  and V sense  relay  108 . PSSR relay  110  can be operated to control a voltage sense connection to the power supply  104 . In another embodiment, the single channel relay  100  connects a cycler (not shown) functioning as both the load and the power supply to a DUT ( 106 ). 
         [0019]    The single channel relay  100  of  FIG. 1  can be expanded to a control multiple DUTs. With reference to  FIG. 2 , a three to one cell multiplexed relay channel is illustrated. Multiplexed relay channel  200  connects DUTs  202 ,  204 ,  206  to load  216  and power supply  104 . Each DUT is connected to load  216  via switches. For Example, DUT  202  can be connected by contactor switches (e.g., cont 1 +  208  and cont 1 −  210 ) and V sense  switches (e.g., V sense   1 +  212 , and V sense   1 −  214 ). The power to the multiplexed channel can be controlled by a pssr switch  218 . The multiplexed relay channel  200  can operate so that only a single DUT is receiving power at any given time. For example,  FIG. 3  illustrates a control timing chart for the multiplexed relay channel  200  where only one DUT is active at any given time. 
         [0020]    In an embodiment, each contactor switch can be controlled by a dual drive relay. Referring to  FIG. 4 , a schematic of a switch controlled by a dual drive relay is illustrated. Dual drive relay  400  includes a high-side driver  402  relay and a low-side driver  404  relay. Switch  406  can be closed when both the high-side driver  402  relay and the low-side driver  404  relay are closed. High-side driver  402  relay can operate at a slower speed than the low-side driver  404  relay. The open and close speed of each relay can be controlled based on a clock signal input. For example, high-side driver  402  can receive a clock signal from a slow-filter clock (see, for example, clock  500 A illustrated in  FIG. 5A ) and low-side driver  404  can receive a clock signal from a fast-filter clock (see, for example, clock  500 B illustrated in  FIG. 5B ). With reference to  FIG. 5A , slow-filter clock  500 A has a frequency of 0.68 Hz causing the high-side driver  402  to have an open/close time of one to two seconds. With reference to  FIG. 5B , fast-filter clock  500 B has a frequency of 6.80 Hz, causing the low-side driver  404  to have an open/close time of one hundred to two hundred milliseconds. It will be appreciated by one skilled in the art that different open/close times can be achieved for each driver by, for example, altering the frequency of each respective clock. 
         [0021]    The multiplexed relay channel  200  can be managed by controlling input signals to the multiplexed relay channel  200 .  FIG. 6  is a schematic of input signals for controlling the operation of the multiplexed relay channel  200 . In an embodiment, the multiplexed relay channel  200  can receive, as input, signals for selecting a DUT and for selecting a state of the multiplexed relay channel  200 . For example, the input signals  600  can include signals for selecting a DUT  602 B,  604 B,  606 B. Additional or fewer DUT selection signals can be received based on, for example, the number of DUTs that can be connected to the multiplexed relay channel  200 . The input signals  600  can further include signals for controlling the operation of the multiplexed relay channel  200 . For example, the input signals  600  can include signals to enable the multiplexed relay channel  200  (e.g., enable signal  608 B), enable contactor switches (e.g., contactor_on  610 B), enable V sense  switches (e.g., V sense     —   on  612 B), and control power (e.g., pssr_on  614 B) to the multiplexed relay channel  200 . The input signals can be turned on or off by closing or opening switches associated with each input signal. For example, switches  602 A,  604 A,  606 A,  608 A,  610 A,  612 A,  614 A each control one of the input signals illustrated in  FIG. 6 . Each input signal can have a default state (e.g., input switch  602 A can have a default state of open and input switch  608 A can have a default state of closed). Each individual switch can be manually or automatically toggled (not shown). For example, switch  602 A can be toggled when the number ‘1’ is pressed on a keyboard (not shown) in communication with switch  602 A. In a further example, switch  602 A can be toggled programmatically by execution of software by a processing system or by execution of hardware logic. In a further embodiment, inputs switches can be controlled by manual selection, automatic selection, or both. 
         [0022]    The multiplexed relay channel  200  can ensure that only one DUT is connected to load  216 . With reference to  FIG. 7 , a schematic of safety logic for controlling operation of the multiplexed relay channel is illustrated. The safety logic  700  can generate a not_clr signal  704  to disconnect all DUTs  202 ,  204 ,  206  from the load  216 . In an embodiment, the safety logic  700  receives, as input, DUT selection signals  602 B,  604 B,  606 B. The safety logic  700  can detect if more than one DUT selection signal  602 B,  604 B,  606 B is active. It will be appreciated by one skilled in the art that the safety selection logic  700  can be modified to support additional or fewer DUT selection signals. In a further embodiment, the safety selection logic  700  can receive an enable signal  608 B. The enable signal  608 B can disconnect all DUTs  202 ,  204 ,  206  from the load  216  without relying on DUT selection signals  602 B,  604 B,  606 B. 
         [0023]      FIG. 8A  is a schematic of a drive controller  800 A for controlling a high-side driver  402  relay of a positive side of multiple contactor switches. A flip-flop  802 A can be used as a trigger latch to open or close a high-side driver  402  relay for one or more contactor switches (e.g., positive side of contactor switch  208 ). In an embodiment, the flip-flop  802 A receives an input signal  804 A. The input signal  804 A can be based on, but not limited to, DUT selection signal  602 B and contactor_on signal  608 B. For example, the  804 A signal can be a high signal when both DUT selection signal  602 B and contactor_on signal  608 B are in a high state. The flip-flop can output a signal that can generate a cont 1 +_send signal  806 A. The flip-flop output signal can be updated, for example, with each positive-going pulse of clock signal  502 A. The flip-flop  802 A can also receive the not_clr signal  704 . In an embodiment, the not_clr signal  704  can cause all outputs (e.g., cont 1 +_send  806 A) to open the high-side driver  402  relay to which the signal is transmitted to. In a further embodiment, the flip-flop  802 A can control additional types of switches. For example, flip-flop  802 A receives as input the pssr_on signal  614 B and outputs a pssr_send  808 A signal, based on, but not limited to, the pssr_on signal  614 B, a psser_send  808 A signal. The pssr_send  808 A signal can be used to control, for example, but not limited to, the high-side driver  402  relay of the pssr switch  218 . 
         [0024]      FIG. 8B  is a schematic of a drive controller  800 A for controlling a low-side driver  404  relay of a negative side of multiple contactor switches. A flip-flop  802 B can be used as a trigger latch to open or close a low-side driver  404  relay for one or more contactor switches (e.g., negative side of contactor switch  208 ). In an embodiment, the flip-flop  802 B receives the input signal  804 A. The output signal  806 B can be updated, for example, with each positive-going pulse of clock signal  502 B. The flip-flop  802 B can also receive the not_clr signal  704 . In an embodiment, the not_clr signal  704  can cause all outputs (e.g., cont 1 +_rtn  806 B) to open the low-side driver  404  relay. In a further embodiment, the flip-flop  802 B can control additional types of switches. For example, flip-flop  802 B receives as input the pssr_on signal  614 B and outputs a pssr_rtn signal  808 B, based on, but not limited to, the pssr_on signal  614 B. The pssr_rtn  808 B signal can be used to control, for example, but not limited to, the low-side driver  404  relay of the pssr switch  218 . 
         [0025]    In an embodiment, the flip-flop  802 A is connected to slow-filter clock  500 A and flip-flop  802 B is connected to fast-filter clock  500 B. Thus, the high-side driver  400  relays that receive signals based on flip-flop  802 A can close more slowly than the low-side driver  404  relays that receive signals based on flip-flop  802 B. The difference in the speed of opening and closing can allow sufficient time for arc quenching and opening of other contactors on different cells. The frequency of clocks  500 A and  500 B can be adjusted to allow for faster or slower opening and closing times for high-side driver  402  relays and low-side driver  404  relays. For example, the difference in the respective speed of operation of the high-side driver  402  and low-side driver  404  can be reduced to decrease the time permitted for arc quenching. In another example, the difference in the respective speed of operation of the high-side driver  402  and low-side driver  404  can be increased to extend the time permitted for arc quenching. In a further example, the difference in the respective speed of operation of the high-side driver  402  and the low-side driver  404  can be adjusted based on the contactor switch used, the desired speed of switching, or both. 
         [0026]    In an embodiment, the multiplexed relay channel can include contactor switches on a return line from a DUT. For example, multiplexed relay channel  200  includes the cont 1 − switch  210  on the return line from DUT  202 . Referring to  FIGS. 8C and 8D , schematics of drive controllers  800 C and  800 D for controlling the high-side driver  402  and low-side driver  404  relays of contactor switches on a return line are illustrated. In a further embodiment, the multiplexed relay channel can include switches on the send and return V sense  lines (e.g., V sense   1 +  212  and V sense1 −  214 ). The V sense  switches can be controlled by a high-side driver  402  relay and a low-side driver  404  relay in the manner described above. Referring to  FIGS. 9A-9D , schematics of drive controllers  900 A,  900 B,  900 C, and  900 D for controlling the high-side driver  402  and low-side driver  404  relays of V sense  send line and V sense  return line switches are illustrated. 
         [0027]    The foregoing description of embodiments of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the present invention to the precise form disclosed, and modifications and variations are possible in light of the above teachings or may be acquired from practice of the present invention. The embodiments were chosen and described in order to explain the principles of the present invention and its practical application to enable one skilled in the art to utilize the present invention in various embodiments, and with various modifications, as are suited to the particular use contemplated.