bonitron M3460, Руководство для пользователей

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D_M3460_D_CMAN_vall_00a 4/17/2020
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process. A general estimate of needs must be used to build a capacitor bank and then
the actual values must be cross checked to make sure they are suitable.
There are several steps in the process. The capacitor bank will be comprised of
capacitors connected in series for voltage support, with one or more strings in parallel
to support the energy requirements.
However, an additional power supply, the ASM 3460PS is required when the total
voltage across the ultracapacitor bank is lower than the Precharge Complete Voltage
(PCC). See Table 6-3 for the minimum PCC voltage required to bring the Ride-Thru
into operation.
Since the extraction losses due to the electrostatic resistance (
𝐸𝑠𝑟
) of the capacitor
can be significant, they must be taken into account. If the
𝐸𝑠𝑟
losses get too high,
parallel capacitor strings can be used to reduce the current in each series string.
The steps to specify the string will include:
1. Determine the energy required for the outage.
2. Determine the minimum voltage acceptable for full power backup.
3. Determine the maximum current required to support the load at minimum
voltage.
4. Specify the capacitor to be evaluated.
5. Estimate the losses for each capacitor.
6. Determine the minimum number of capacitors per series string required for the
minimum voltage.
7. Add capacitors in series for outage energy.
8. Determine if parallel strings are required to provide outage energy.
These are the definitions of the variables we will use in the following equations:
𝐶
𝑒𝑜𝑙
- Capacitance at end of life
𝐶
𝑡𝑜𝑡
- Total capacitance of the entire cap bank
𝐸𝑠𝑟
𝑡𝑜𝑡
- Total equivalent ESR for the entire cap bank
𝐸𝑠𝑟
- Internal resistance at end of life
𝐼
𝑝𝑒𝑎𝑘
- Peak current into the M3460R during the discharge cycle
𝐽
𝐴𝑣𝑎𝑖𝑙𝑎𝑏𝑙𝑒
- Total energy in charged capacitor bank prior to discharge
𝐽
𝐿𝑜𝑠𝑠𝑇𝑜𝑡
- Total losses during discharge
𝐽
𝑜𝑢𝑡
- Energy required to hold up the system during the outage
𝑛
𝑠𝑒𝑟𝑖𝑒𝑠
- Number of capacitors in each series string
𝑃
𝑠𝑦𝑠
- System power in kilowatts
𝑇
𝑜𝑢𝑡
- Time outage in seconds
𝑉
𝐶ℎ𝑎𝑟𝑔𝑒
- Charge voltage at beginning of discharge
𝑉
𝐶𝑎𝑝𝐸𝑛𝑑
- The capacitor string voltage at the end of the discharge
𝑉
𝐶𝑎𝑝𝑀𝑎𝑥
- Maximum charge voltage for the capacitor
𝑉
𝑒𝑛𝑑
- Lowest voltage the capacitor bank can reach
𝑉
𝑇𝑒𝑟𝑚𝐸𝑛𝑑
- Terminal voltage of an individual capacitor during discharge