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POWER ELECTRONICS crete packages or modules with low lead inductance. The voltage spike increases as load current is increased, therefore it can be mitigated by slightly over-rating the device or paralleling multiple devices. The Voltage spike can be finally reduced by increasing Rgoff, hence a split Rgon- Rgoff driver stage is preferred for the F version, keeping the Rgon as low as possible to meet the required EMI specs and increasing Rgoff the meet de-rating specification of normally 80% Vbrces. The HighSpeed 5 provides drastically improved performance compared to HighSpeed 3 across the whole range of electrical parameters: lower conduction Fig. 3: Electrical parameter comparison (left) and Trade-off Vcesat/Eoff (right) of the losses, higher blocking voltage, lower HighSpeed 5 in comparison to previous technologies HighSpeed 3 and TrenchStop. switching and capacitive losses, lower gate charge – see figure 4. This results in a drastically improved equivalent to 430 Million of kWh saving in one year, assuming a Vcesat-Eoff trade-off compared to previous 600V IGBT genera- utilization rate of 50%. tions as shown on figure 3. The device can work at relatively high switching frequency of 60 kHz, where normally 20kHz are used by conventional IGBTs. Tested in power factor correction This translates in the possibility to reduce the size of the PFC We verified the improvement of the new technology by ex- choke still keeping the same ripple current, and hence reduce tensive characterization and application test. Figure 4 shows an system cost. Even more interesting are the thermal results: efficiency test in a 1 kW CCM mode PFC test board, where the thanks to the reduced power dissipation, the HighSpeed 5 in HighSpeed 5 (H5) is compared to previous generation High- TO-220 package can reduce the case temperature compared Speed 3 (H3) and competitor’s IGBTs commonly found in these to previous IGBTs housed in the much bigger TO-247 pack- applications. Switching frequency is 60 kHz in this case. age (up to 30°C compared to the best competitors at 800W). The HighSpeed 5 shows an efficiency improvement of 0.5% This enables designers to save board space due to the smaller to the HighSpeed 3 and 1% to the best competitor. footprint, while reducing the cooling requirement and finally The PFC circuit is normally the AC/DC conversion stage reducing the overall solution cost. of motor drives to be found in modern air conditioning split systems above 1 kW. Assuming that the air conditioning is run- Tested in solar inverters ning on average at 50% load and an efficiency of 95% for the Before looking into the real application of a solar inverter, inverter stage, this would translate in 5W average power saving let’s firstly get a direct feeling of the power loss improvement of for each air conditioning unit sold with a HighSpeed 5 IGBT H5 against previous generation HighSpeed3. Based on a very on it. Considering that only the top 4 aircon suppliers in China simple condition of a 20A square wave with 50% duty cycle, produce approximately 25 Million inverted aircon units/years, junction temperature 100°C, the total power loss per IGBT vs this would result in a power saving of 100MW in China only, switching frequency is shown in figure 5. Fujitsu relays Fujitsu Relays Automotive, Power, Signal, High frequency, Solid state Fujitsu presents new developments at Electronica 2012 B5, 343 main emea.fujitsu.com/relays A6, A08 automotive www.electronics-eetimes.com Electronic Engineering TimesEurope November 2012 51


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