阅读说明：本技术 用于在高电压范围内操控半导体功率开关的设备 (Device for actuating a semiconductor power switch in a high voltage range ) 是由 A·亨纳 H·雷西贝格尔 K·弗莱德 于 2020-05-06 设计创作，主要内容包括：本发明提供了一种用于借助于驱动电压来操控多个半导体功率开关(S12、S21)的设备,所述驱动电压用于多个负载(Last1、Last2)在高电压范围内的有时钟节拍的运行,其中,所述半导体功率开关的驱动电压(Uh-(1)、Uh-(2))能够通过变压器提供。根据本发明设置,用于所述半导体功率开关的驱动电压(Uh-(1)、Uh-(2))从所述变压器的唯一次级绕组的电压导出,其中,设置有电子电压电平转换器电路,以便从所述变压器的次级绕组中以所需大小获得所述驱动电压(Uh-(1)、Uh-(2))。(The invention relates to a device for controlling a plurality of semiconductor power switches (S12, S21) by means of a drive voltage for a clocked operation of a plurality of loads (Last1, Last2) in a high voltage range, wherein the drive voltage (Uh) of the semiconductor power switches 1 、Uh 2 ) Can be provided by a transformer. According to the invention, the driving voltage (Uh) for the semiconductor power switch 1 、Uh 2 ) Derived from the voltage of the only secondary winding of the transformer, wherein an electronic voltage level converter circuit is provided to obtain the drive voltage (Uh) from the secondary winding of the transformer in the required magnitude 1 、Uh 2 )。)

1. Device for the simultaneous actuation of a plurality of semiconductor power switches (S12, S21) in a high voltage range with pulsed loading (Last1, Last2), wherein the drive voltage (Uh) of the semiconductor power switches₁、Uh₂) Can be provided by a transformer, characterized in that a drive voltage (Uh) for the semiconductor power switch₁、Uh₂) Derived from the voltage of the only secondary winding of the transformer, wherein an electronic voltage level converter circuit is provided to obtain the drive voltage (Uh) from the secondary winding of the transformer in the required magnitude₁、Uh₂)。

2. The apparatus of claim 1, wherein the electronic voltage level translator circuit comprises a charge pump (C1, R1, D1; C2, R2, D2).

3. The device according to claim 2, wherein the clock ticks of the respective loads (Last1, Last2) are used for the clock ticks of the respective charge pumps.

4. The device according to claim 3, wherein the clock pulses of the device are each implemented by a switch (S1, S2) which is connected to the secondary winding of the transformer and which, in the closed state, charges the charge pump and, in the open state, charges the drive voltage (Uh) generated in the charge pump₁、Uh₂) To the respective semiconductor power switches.

Technical Field

The invention relates to a device for the simultaneous actuation of a plurality of semiconductor power switches in a high voltage range under pulsed loading.

Background

The actuation of a semiconductor power switch by means of a conventional device of the type mentioned at the outset is explained with the aid of fig. 1 and 2.

As shown in fig. 1, in order to actuate two semiconductor power switches (MOSFET, IGBT, bipolar transistor), the 15V voltage required for actuation at the control input (gate, base) always has a defined potential difference from the reference level when the switch is switched on. If this is not the case, the switch cannot be turned on. In the worst case, this can even lead to damage to the semiconductor power switch. The reference level can be, for example, 0V (circuit variant on the left in fig. 1) or 500V (circuit variant on the right in fig. 1) in the high-voltage application shown in fig. 1, and can even jump from 0V to 500V when the power switch is switched off or on (high-side problem).

For applications in the high-voltage range, which are shown by way of example in fig. 2, the drive voltages UL1, Uh are generated by means of a transformer having a plurality of output voltages₁And Uh₂These output voltages provide drive voltages at different reference levels in galvanic isolation. In particular, the first load Lastl and the second load Last2 are clocked with the zero potential HV-and the positive potential HV +, for example 500 volts, by a pair of electronic power switches S1, S12 and S2, S21, respectively. The drive voltage UL1 for operating the switch S1 is tapped from the first secondary winding of the transformer (in fig. 2 the lower secondary voltage of the transformer). Drive voltage Uh for actuating switch S12₁Is tapped from the second secondary winding of the transformer (the upper secondary voltage of the transformer in fig. 2). Drive voltage Uh for actuating switch S21₂Is tapped from the third secondary winding of the transformer (the upper secondary voltage of the transformer in fig. 2). With the switches S1, S12 and S2/S21 closed, a high voltage is applied to the respective loads Lastl and Last2 and with the switches open with the loads Lastl and Last2And (4) load separation.

Due to the compact winding structure, electromagnetic interference caused by the clock pulses of the power semiconductors is transmitted to the primary side of the transformer. Thus, in automotive applications, disturbances generated in the HV portion of the device are transmitted to the low voltage side. Furthermore, the generated interference may lead to voltage peaks on the further secondary winding of the transformer. These interferences have to be reduced relatively cost-effectively by means of EMV filter components. Another disadvantage of this approach is the use of a transformer with multiple secondary windings. These secondary windings are costly and expensive due to the required dielectric strength and the use of high quality and therefore expensive insulating materials.

Disclosure of Invention

The object of the present invention is to provide a device which can be optimized with respect to EMV and can be produced cost-effectively.

This object is achieved by the features of claim 1. Advantageous embodiments of the invention are defined in the dependent claims.

The invention therefore provides a device for actuating a plurality of semiconductor power switches by means of a drive voltage for clocked operation of a plurality of loads in a high voltage range. The drive voltage is provided by a transformer, wherein the drive voltage for the semiconductor power switch is derived by a single secondary winding of the transformer. A voltage level translator circuit is provided which extracts a drive voltage having a desired voltage level from the voltage generated in the secondary winding of the transformer.

Preferably, only one transformer with only one secondary winding is required. The drive voltages for any number of PWM controlled loads are preferably generated by simple electronic voltage level shifter circuits, respectively.

The device according to the invention is more compact and has less EMV interference than a device according to the prior art with multiple secondary windings.

The transformer and EMV filter components are less expensive and result in significant cost savings.

The electronic voltage level translator circuit is based on a charge pump scheme. The term "charge pump" includes a variety of different circuits that increase the value of a voltage or reverse the polarity of a dc voltage.

The charge pump acts as a voltage converter without requiring a large output current or without using suitable magnetic means, such as a coil.

The charge pump sets its voltage to different values through a time sequence between the charging of the capacitor and the cascade. This is achieved by periodic switching of the switch.

These processes are similar to reciprocating piston pumps. The charging of the capacitor corresponds to the filling of the cylinder and the cascading corresponds to the power increase of the cylinder. The diode, which is switched on by a potential difference into the blocking range or the conducting range and charges the capacitor or boosts its voltage, respectively, preferably acts as an electronic switch. The charge pump is capable of generating very high dc voltages in a multiple cascade fashion. Such a circuit is called a high voltage cascade.

Advantageously, the clock rate of the respective load is used for the clock rate of the respective charge pump, in particular the PWM pulses of the respective load are used for the clock rate of the charge pump. Thereby greatly simplifying its circuit design.

The clock pulses of the device are preferably each implemented by a switch, which is connected to the secondary winding of the transformer and which charges the charge pump in the closed state and which applies the drive voltage generated in the charge pump to the respective semiconductor power switch in the open state. The charge pump clock pulses are preferably implemented in each case by a power switch Sn of the PWM switch. Thus, in the closed state of S1, for example, capacitor C1 is charged to voltage UL1 through D1-R1. In the off state, C1 discharges to C12 through D12. Diode D1 turns off and the charged capacitor is adjusted to the reference level of power switch S12. The driver is supplied with the necessary voltage from S12 via Uh1 UL1 UL 15V.

Drawings

The invention is explained in detail below with the aid of the figures; shown in the attached drawings:

fig. 1 shows generally the operation of a semiconductor power switch (MOSFET, IGBT, bipolar transistor) according to the prior art,

fig. 2 shows the use of the actuation of fig. 1 in the high-voltage range by means of a transformer for the galvanic separation of the respective drive voltages for the circuit breakers, the drive voltages for the circuit breakers being galvanically separated by means of the secondary winding of the transformer, and

fig. 3 shows an embodiment of a device according to the invention for actuating a power switch by means of a transformer having a single secondary winding from which different drive voltages for the power switch are derived.

Detailed Description

Figures 1 and 2 are explained in the introductory part with respect to the prior art.

Fig. 3 shows an embodiment of the device according to the invention. This embodiment differs from the device shown in fig. 2 in that the drive voltage UL1 is supplied to the electronic load switches S1, S2 by using a transformer with a single secondary winding, in more detail the drive voltage UL1 is supplied to the two electronic load switches S1 and S2 by means of the lower secondary winding of the transformer with three zero potential HV-levels.

Drive voltage Uh for actuating electronic load switches S12 and S21₁And Uh₂The device of fig. 3 is not supplied via the other secondary winding of the transformer, but is derived from the only secondary voltage of the transformer by means of a charge pump.

For supplying a drive voltage Uh₁Comprises a capacitor C1 which is connected on the one hand to the side of the load Last1 which is connected to the switch S1 and on the other hand via a series resistor R1, the other end of which is connected to a diode D1 at the UL1 potential. The drive voltage Uh generated by the charge pump from the voltage UL1₁Is applied via a diode D12 to an electronic switch S12, which is bridged on the input side by a capacitor C12.

For supplying a drive voltage Uh₂Comprises a capacitor C2, the capacitanceThe latter is connected on the one hand to the side of the load Last2 which is connected to the switch S2, and on the other hand via a series resistor R2, the other end of the capacitor is connected to a diode D2 which is at the potential of UL 1. The drive voltage Uh generated by the charge pump from the voltage UL1₂Is applied via a diode D12 to an electronic switch S12, which is bridged on the input side by a capacitor C21.

When the switch S1 is closed, the capacitors C1, C2 are charged to the drive voltage potential UL through the series resistors R1, R2 and the blocking diodes D1, D2.

If the switches S1, S2 are open, the capacitors C12, C21 are charged with the charge of the capacitors C1, C2. This provides the potential Uh required for actuating the switches S12, S21₁(Uh₂) UL. This process is periodically repeated at the clock ticks of the switches S1, S2.

The device according to the invention has been explained in terms of an embodiment with two semiconductor power switches. However, the present invention is not limited thereto. Rather, more than two such switches can be considered for a device for actuating a semiconductor power switch.