PGH15016AM

PGH NIEC | Alldatasheet

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3-phase diode bridge plus thyristor PGH series Power Module S. Hashizume Dec., 2007 Rev.1.0 PGH308 30 800 E-15 PGH3016AM 30 1600 E-36 PGH508AM 50 800 E-36 PGH5016AM 50 1600 E-36 PGH758AM 75 800 E-36 PGH7516AM 75 1600 E-36 PGH1008AM 100 800 E-36 PGH10016AM 100 1600 E-36 PGH1508AM 150 800 E-43 PGH15016AM 150 1600 E-43 PGH2008AM 200 800 E-43 PGH20016AM 200 1600 E-43 Part Number IT(AV), IF(AV) (A) VDRM ,VRRM (V) Case Outline 75mm 34mm 41.5mm 97.5mm 108mm 62mm E-15 E-36 E-43 PGH series Packages PGH series PGH series power module includes 3-phase diode bridge and inrush current limiting thyristor in a package. This seri es are widely applied to rectification circuit in popular 3-phase inverters. This paper shows how to use PGH series, and also covers information on 3-phase rectification cir- cuit, driver circuit, and selection of heatsink. In addition, it provides designers, who are not very familiar with thyristor, with its basic application information. List of PGH series

Average current IdAVG 0.5 IdAVG 0.5 IdAVG 0.333 IdAVG RMS current 1.57 IdAVG 0.785 IdAVG 0.785 IdAVG 0.579 IdAVG Peak current 3.14 IdAVG 1.57 IdAVG 1.57 IdAVG 1.05 IdAVG Average current 0.5 IdAVG 0.5 IdAVG 0.333 IdAVG RMS current 0.707 IdAVG 0.707 IdAVG 0.578 IdAVG Peak current IdAVG IdAVG IdAVG Peak reverse voltage to Diode 1.41 eRMS 2.82 eRMS 1.41 eRMS 2.45 eRMS DC output voltage Peak /Average 3.14 1.57 1.57 1.05 2 1.73 AC input voltage Line voltage/Phase Voltage AC input voltage RMS / Average 2.22 1.11 1.11 0.428 e Id RMS AVG Id e e RMS RMS AVG e Id RMS AVG e e e Id RMS RMS RMS AVG Each diode Resistive load) Each diode Inductive load) Table 1 Constants of rectification circuits 200V RMS 200V RMS 200V RMS 28.2Ω Diode current 490V Diode voltage An example of diode current and voltage in three phase full-wave rectification circuit

follows. For AC200V line : VDRM and VRRM : 800V For AC400V line : VDRM and VRRM : 1,600V Between AC line and bridge rectifier, use appro- priate AC line filter. It reduces the noise entering into the equipment not so as to cause any unde- sired behaviors. Furthermore, it suppresses con- ducted emission from the equipment. As are ex- pected, external stresses on diode and thyristor, such as surge voltage and current, can be de- creased by such filter.

• Thyristor 1, What’s thyristor Thyristor is considered as a diode and a switch connected in serial. Same as bipolar transistor, thyristor is driven by current. With respect to bipolar transistor, when base current is applied, collector current of h FE times base current flows. In contrast, thyristor is switched on by gate current that is higher than a specific value (gate trigge r current). The follow- ing figure illustrates these relationships. You will see that collector current of bipolar transistor flows during the whole period when base current flows, but thyristor keep s anode current flowing even after the gate current is cut off. So, you need not supply thyristor with continuous gate current TDK 3-phase line filter and internal diagram Thyristor (SCR) i v E Anode Cathode Gate iG vT i E iG Bipolar transistor (NPN) Collector Emitter iC vCE E Base iB vCE(sat) iC E iB hFE×iB Anode Cathode Gate Thyristor

during all of the on-period. At present, major switching devices, such as MOSFET and IGBT, are driven by voltage, but thyristor is current- driven device. Please keep in mind this fact when you design gate firing circuit for thyristor. 2, Behaviors of Thyristor as a switch — Holding current, and Latching current 2-1, Holding current Once thyristor turns on, the on-state is main- tained as far as anode current is larger than a cer- tain value. In other words, thyristor turns off when anode current decreases to a certain value. The “certain current” is the holding current, and that of PGH308 (30A 800V) is 70mA typical at 25℃. ( Refer to individual datasheet.) Now, let's see the influence of holding current in an actual circuit. Supposing that pulse trigger current is applied only once. Thyristor is turned on, however, if the load is resistive and anode-cathode voltage goes to zero, anode current altogether decreases to below holding current. After that, positive voltage would be applied to anode, however, thyristor maintains off-state so far as gate current would be applied again. 2-2. Latching current Assume that, due to slow rise of anode current, the current doesn’t reach a certain level before gate current is terminated, thyristor turns off. It follows that, after removal of gate current, the minimum anode current which can maintain on- state is the latching current. For example, typical latching current of PGH308 (30A 800V) is 90mA （25℃). If thyristor cannot be turned on or on-state may not be able to maintain, increase gate pulse width or try multiple gate pulses. Both holding current and latching current are temperature-dependent, and they become larger at low temperature. Compared with at 25 ℃, they are about twice lar- ger at –40℃. Time Anode current decreases. Holding current ON OFF Thyristor turns off. Holding current e IT e IT Gate current Thyristor turns off when anode current be- comes below holding current. Time time Latching current Pulse gate current Anode current Thyristor turns off because of slow rise of anode current. Latching current Gate trigger current Gate current turns on Thyristor

3, Gate drive 3-1 How to achieve sure turn-on 3-1-1 Temperature dependence of gate char- acteristics In datasheet of PGH308, you will find a graph of gate characteristics like this. This graph shows required gate current and voltage to trigger all the PGH308 at -40℃, at 25℃ and 125℃. For example, we know that DC cur- rent of 100mA can turn on every PGH308 at 25℃, and accompanied gate voltage is less than 2.5V. Based on this graph, let us find out how large is the gate trigger current at a certain temperature, which comes from the lowest operating tempera- ture of the equipment in which the thyristor will be installed. Trigger currents at -40 ˆ, 25 ℃, and 125℃ are plotted on the graph like below, and we can estimate that trigger current at –20℃ is around 150mA. 3-1-2 Pulse width dependence of gate trigger current In case that pulse gate current is applied, and pulse width is shorter than 20µs, required gate current to turn on thyristor is large compared with DC. Furthermore, a remarkable increase in gate trigger current is needed when the pulse duration falls below 10 µs specifically. For example, pulse trigger current of 5µs width is twice larger than DC. Assuming that the minimum operating tem- perature is -20℃ and pulse width is 5µs, the esti- mated peak trigger current is 300mA (150mA × 2). Accordingly, combination of dependence in temperature and dependence in pulse width will give you how large is the required gate current to trigger. 3-2 Ratings of gate current, voltage, and power Rating is the limit where stress on device may spoil its reliability significantly or cause catastro- phic damage. As shown on the graph below, the three ratings - peak gate current, voltage, and power (gate current times gate voltage) - are de- fined. In addition, average gate power is also limited. For detailed information, refer to indi- vidual datasheet. To turns on thyristor firmly, gate current and gate voltage tend to become high. Be careful in average power for DC triggering, and in peak power for pulse triggering. 3-3 T o a v o i d tr i g g er b y n o i s e ( T o a v o i d ma l - function) The maximum gate voltage not to trigger is DRM）. This implies that more than 0.25V between gate and cathode may possibly turn on the thyristor. 5µs 2µs 10µs 20µs 50µs Pulse width Factor of pulse gate current Typical pulse trigger current Gate ratings Gate voltage : less than 10V Power:Less than 5W Gate current : less than 2A All triggered at-40℃ 200mA 100mA Junction temperature Trigger gate current Temperature dependence of gate current

In order to avoid unintended turn-on by noise (malfunction), such measur es are expected to be effective. *Connect cathode of trigger signal to the terminal ex- clusive for trigger. *Gate serial diode Noise as high as diode forward voltage (approximately 0.7 V) is cancelled. However, the drive signal is cut by the voltage, and, if necessary, it should be compensated.. *Gate parallel diode The diode may prevent an excessive gate reverse voltage. *Gate parallel capacitor （0.01～0.1µF） 3-4 Gate load line A gate load line is used to specify the power- supply voltage to gate trigger circuit, and current- limiting resistance (including power supply inter- nal resistance). Accordingly, considering mini- mum operating temperature and width of trigger- ing pulse, we can design gate driver that can turn- on every device, where drive current, voltage, and power are all well within the corresponding rat- ings. As shown in the figure below, at first, plot open- circuit power-supply voltage of the gate trigger circuit on the voltage axis (vertical axis), and plot short-circuit current at the current axis (horizontal axis). Then, link these two points by straight line. This gate load line should exceed area that all devices can be triggered, and should also satisfy all the ratings - gate current, gate voltage, and gate power. In this example, short-circuit current is 0.5A, and open voltage is 8V. Therefore, we know that the current-limiting resistance is 16 Ω. The load line is a classical way of thinking. At present, we can easily realize constant-voltage or constant-current drivers. IGBT and MOSFET are driven by voltage, however, thyristor is driven by current. Consequently, when designing gate driver for thyristor, apply constant-current basis design. Incidentally, reverse power loss of thyristor in- creases significantly in case of applying DC gate current while reverse voltage is applied to anode to cathode. Because reverse voltage isn't applied to PGH in standard applications, this fact is not meaningful. However, remember that it’s an im- portant nature of thyristor. ４, Thermal design (Choice of heatsink) Including PGH, base plate of power module is generally made of copper. However, unless combined with heatsink, temperature rise is so Terminals for trigger Measures to avoid gate malfunction Design example of gate load line Total16Ω 30A PGH508AM Gate to cathode voltage :less than 10V Power : less than 5W Gate current: less than 2A All triggered consider- ing operating tempera- ture and pulse width Gate load line

and 10ms. Here, the I is RMS current. Assuming that 1 pulse surge on-state current is 600A, I2t can be calculated as follows. This figure is useful when thyristor is protected by (cutting) fuse. There is a similar regulation in fuse, too, so we can choose a matched pair where thyristor doesn't fail but fuse is broken. Critical rate of rise of turn-on current di/dt de- fines how large is the destructive limit below 2ms. After gate current is applied, it takes about 100 µs before all the area of thyristor turns into on-state. In other words, if pulse width of current is very short, partial conduction occurs. As a result, small area owes the power, and power density in the area also becomes very high. It is the di/dt that, for such reason, prescribes the rating against sharp rising current pulse. These three current rating are represented on common time axis as follows. At present, we don’t worry whether major power switching devices, such as MOSFET or IGBT, would withstand starting-up current or not even if how fast it is. This is because very small unit-cells are accumulated in one chip, and their high frequency characteristics are remarkably excellent compared with thyristor. By contrast, general thyristor is made of single thyristor unit. Therefore, on-region begins from neighborhood area of gate, and it spreads to the whole chip with time. If critical rate-of-rise of on-state current di/dt is 100A/µs, for example, thyristor may fail when anode current reaches more than 100A at 1 µs, 200A at 2 µs, ･･･ after turn-on (after gate current begins to flow). The initial turned-on area de- pends on gate drive current. The faster and the larger on-gate is, the larger initial turn-on area is. For that reason, faster and larger gate current, such as i G=200mA and , diG/dt=0.2A/µs, is specified as standard condition for di/dt for a thyristor that has maximum trigger gate current of 50mA at 25 °C. When high di/dt is anticipated, additional reactor in the anode current loop is effective to suppress di/dt. Additionally, enough large and sharp on- gate current within gate ratings, is also valid to improve di/dt capability of thyristor itself. 5-2 Critical rate of rise of off-state voltage dv/ dt As explained, thyristor is normally turned on by gate current. However, it may be also turned on by high dv/dt of anode voltage. It is the critical rate of rise of off-state voltage dv/dt, which pre- scribes the limit of rising. Displacement current into inner capacitance of thyristor chip has similar effect to gate current. The dv/dt is a typical cause of thyristor mal- functions. Thyristor chips which have dv/dt ca- pability of 100V/µs or more have internal resis- tance that can bypass displacement current. Countermeasures against malfunction by dv/dt include application of thyristor that has higher dv/ dt capability, addition of RCD to gate circuit same as for noise, and controlling dv/dt itself by CR snubber. Excessive dv/dt is applied Thyristor turns on. 2ms 10ms di/dt I2t ITSM 50Hz Cathode Gate On-region spreads with time On-region spread of Thyristor chip