Open Frame Module

Ultracapacitor module for energy storage systems.

Open Frame Module

AEP Hybrid Power offers a cost effective structure to mount the ultracapacitors in cubicles. The so called “Open Frame Modules” are frames which an advanced way of balance and monitored the ultracapacitors. This prevents dangerous situations and obtains the maximum lifetime from the ultracapacitors. Each module is able to support up to 48 Ultracapacitors and could be charged up to 120VDC. The balancing and monitoring structure is based on three levels: Individual cell level, unit level and system level. On all levels the voltage and temperature are measured as these are the most important parameter for the lifetime and performance of the Ultracaps. When required also a current sensor could be implemented.

Information about Monitoring, Controlling and Communication

Balancing Unit (BU)

The Balancing Unit consists of two identical circuits which provide measurement and balancing functionality for two cells:

  • detection of cell over temperature;
  • detection of cell overvoltage;
  • passive balancing of cells (permanent);
  • active balancing during overvoltage;
  • generation of status output (cell state);

Each BU has a status output (OK-bit) that indicates if the two cells are okay. All balan­cing units of one module are connected in series to the MMU providing a sum status regarding to the cell state. Since the BUs are supplied by the cell voltages there is no external supply voltage needed.

 Monitoring Measuring Unit (MMU)

Each Ultracap module has one MMU providing the following:

  • measurement of module voltage
  • measurement of module temperature
  • evaluate the okay status of all Bus
  • data transmit over RS485 on request
  • Flashing LED when module voltage above 5V additional terminals in the housing to measure the   module voltage or manually discharge.

All MMU’s are connected via RS485-bus to a master monitoring system (e.g. the MCU). The MMU is supplied by the module voltage. For RS485 communication, an external 12V supply is needed.

Monitoring Control Unit (MCU) – not part of the Open Frame Module

For full monitoring support, an additional control device is necessary. The MCU is the AEP Hybrid Power solution for monitoring and control several Open Frame Modules. It is the gateway between the internal (RS485) and the external fieldbus (CAN or RS232/ ProfiBus). The external data interface can also be used as a service interface. Following features are provided by the MCU:

  • collecting all system data (via RS485 interface)
  • measurement of Ultracap current
  • interpretation of system data
  • providing derived system data and status over CAN or RS232/ ProfiBus interface

The MCU request data from all MMUs periodically via RS485 bus and checks that all system parameters are in between the defined ranges. The collected and derived system data is transmitted via CAN (CANopen) or RS232 bus either to the Unigate ProfiBus converter or to an optional service tool.