電氣自動(dòng)化外文及翻譯-電氣類(lèi)(文件)
【正文】 gration of pulsecharging into large scale applications has high potential and should yield the same benefits. Charging of a highvoltage battery pack can be done in two ways. The first is to apply charge to the entire battery pack by one charger. However, most high capacity batteries are usually broken into smaller sections to output desired voltage (., an HEV may want to draw a small voltage for its electronics along with another higher voltage for the electric motor). This characteristic leads to the ability to partition the battery into smaller capacity sections. Therefore, a second way to charge a high capacity battery is to have a series of smaller chargers working on charging small sections at the same time – this is the basic idea behind the proposed charging method. High Capacity Battery Charged as Single Pack A high capacity battery pack consists of either many small battery cells, or larger cells (but fewer in number). As mentioned earlier, pulsecharge’s advantage lies in its ability to allow the battery to rest between pulse cycles to achieve a uniform charge (chemical reaction has time to take place uniformly). In case of a larger battery cell, it is only intuitive that the battery charge cycle must be extended in order to achieve the same effect. An equation for calculating the optimal charge cycle of a battery can then be determined by: restondaryedischrestinitialechT_secarg_argττττ +++= Where T is the total charge cycle time, τ charge is charge pulse duration, τ initial_rest is the initial rest duration, τ discharge is the discharge pulse duration, and τ secondary_rest is the rest time after discharge. Battery evaluation is also performed during the rest time after the discharge. The relationship between the battery capacity and charge time is proposed to have a logarithmic correlation. This relationship is shown below in Figure 2. Figure 2. Charge Cycle Time and Battery Capacity Relationship Charge cycle time can then be calculated as follows: 2)_(log_10?=mAinTCapacityBatteryC Where CT = chargecycle time. Individual time slices within the charge cycle can be calculated using: srestondarysedischsrestinitialsechCCCC4_sec3arg2_1argατατατατ ==== Where ∝ 1 = , ∝ 2 = , ∝ 3 = , ∝ 4 = Therefore, a 1000 mA capacity battery has cycle time of 1 second, τ charge= 980μ s, τinitial rest= 5μ s, τ discharge= 5μ s, τ secondary rest= 10μ s. A 10,000 mA battery will have twice as long charge cycle time and time slices. The Divide and Conquer Approach to Charging a HighCapacity Battery Pack Our proposed method for implementing pulsecharge in highcapacity batteries is to partition the battery pack into smaller sections (possibly already done to acmodate by the electronic requirement variations). This is shown in Figure 3. Figure 3. The Divide and Conquer Method to Charge a HighCapacity Battery Pack. A series of pulsechargers is then applied to charge these sections individually. The reasoning behind this method is that if a battery pack is prised of individual cells, the cells’ characteristics are not identical hence may not charge/discharge at a uniform rate as the pack is in used. Therefore, breaking the pack into smaller sections and charged individually with an intelligent charger allows them to be conditioned correctly and more uniformly. Charging individual sections as shown above is proposed as the better method to charge a high capacity battery pack. However, implementation of this method is more plicated and expensive than charging the pack as a whole. Additional control logic needs to be implemented to keep the chargers’ inputs and multiple load outputs to maintain efficiency. 5. Conclusion Advances in advanced battery charging technology have been numerous, including the development of the battery conditio
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