# US 10,122,357 B2 · Sensorless temperature compensation for power switching devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,122,357 B2 - Document ID: US10122357B2 - Status: Granted - Kind: B2 - Application number: 15/350,278 - Filed: 2016-11-14 - Published: 2018-05-17 - Granted: 2018-11-06 - Earliest claimed: 2016-11-14 - Assignees: Ford Global Technologies, LLC - Applicants: Ford Global Technologies, LLC - Inventors: Xi Lu; Chingchi Chen; Michael W. Degner; Zhuxian Xu; Ke Zou - Web page: https://patentgrep.com/patent/US10122357B2 ## CPC - H03K 17/14: Modifications for compensating variations of physical values, e.g. of temperature - B60L 15/007: {Physical arrangements or structures of drive train converters specially adapted for the propulsion motors of electric vehicles} - B60L 50/51: characterised by AC-motors - H03K 17/567: Circuits characterised by the use of more than one type of semiconductor device, e.g. BIMOS, composite devices such as IGBT - H10W 72/50: Bond wires - H10W 90/00: Package configurations - H02P 27/08: with pulse width modulation - H10W 72/926: {Multiple bond pads having different sizes} - H10W 90/758: {between a chip and a stacked discrete passive device} - H10W 90/759: {between a chip and a laterally-adjacent discrete passive device} - Y02T 10/64: Electric machine technologies in electromobility - Y02T 10/70: Energy storage systems for electromobility, e.g. batteries - H03K: PULSE TECHNIQUE (measuring pulse characteristics G01R; modulating sinusoidal oscillations with pulses H03C; transmission of digital information H04L; discriminator circuits detecting phase difference between two signals by counting or integrating cycles of oscillation H03D3/04; automatic control, starting, synchronisation or stabilisation of generators of electronic oscillations or pulses where the type of generator is irrelevant or unspecified H03L; coding, decoding or code conversion, in general H03M) - B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES - H10W: GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10 - H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS - Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION ## Abstract An inverter for an electric vehicle drive has a bridge including a plurality of power switching devices having respective insulated gate terminals and emitter terminals. A PWM circuit determines switching commands for controlling the bridge. A plurality of gate drivers receive the switching commands and provide gate drive signals to respective gate terminals. A plurality of gate capacitors are each thermally coupled to a respective switching device and are electrically connected between the respective gate and emitter terminals. Each gate capacitor has a negative temperature coefficient adapted to counter changes in a switching speed of the switching devices over a predetermined range of temperature. As a result, a consistent switching speed is maintained so that power loss and switching device reliability are optimal across the full temperature range. ## Claims ### Claim 1 An inverter for an electric vehicle drive, comprising: a bridge including a plurality of power switching devices having respective insulated gate terminals and emitter terminals; a PWM circuit determining switching commands for controlling the bridge; a plurality of gate drivers receiving the switching commands and providing gate drive signals to respective gate terminals; and a plurality of discrete gate capacitors each thermally coupled to a respective switching device and electrically connected between the respective gate and emitter terminals, wherein each gate capacitor has a negative temperature coefficient adapted to counter changes in a switching speed of the switching devices over a predetermined range of temperature. ### Claim 2 (depends on 1) The inverter of claim 1 wherein the switching devices are comprised of a plurality of power semiconductor dies, and wherein each gate capacitor is comprised of a surface-mount device which is mounted on a respective power semiconductor die having the respective switching device. ### Claim 3 (depends on 1) The inverter of claim 1 wherein the switching devices are comprised of a plurality of power semiconductor dies, and wherein each gate capacitor is comprised of a non-surface mount component connected to a respective switching device via jumper wires soldered to a respective power semiconductor die. ### Claim 4 (depends on 1) The inverter of claim 1 wherein the gate capacitors are comprised of ceramic capacitors. ### Claim 5 (depends on 4) The inverter of claim 4 wherein the ceramic capacitors are multi-layer ceramic capacitors. ### Claim 6 (depends on 1) The inverter of claim 1 further comprising a plurality of gate resistors each providing a respective fixed resistance in series with a respective gate terminal, wherein the fixed resistance is configured to provide a predetermined switching time when the gate capacitors are at a highest temperature in the predetermined range of temperature. ### Claim 7 A power switching circuit for an inverter bridge, comprising: an insulated gate transistor with gate, collector, and emitter terminals and having a switching time varying over a predetermined range of temperature; and a discrete gate capacitor thermally coupled to the transistor and electrically connected between the gate and emitter terminals, wherein the gate capacitor has a negative temperature coefficient adapted to counter changes in the switching speed of the transistor over the predetermined range. ### Claim 8 (depends on 7) The circuit of claim 7 wherein the transistor is comprised of a power semiconductor die, and wherein the gate capacitor is comprised of a surface-mount device which is mounted on the power semiconductor die. ### Claim 9 (depends on 7) The circuit of claim 7 wherein the transistor is comprised of a power semiconductor die, and wherein the gate capacitor is comprised of a non-surface mount component connected to the transistor via jumper wires soldered to the power semiconductor die. ### Claim 10 (depends on 7) The circuit of claim 7 wherein the gate capacitor is comprised of a ceramic capacitor. ### Claim 11 (depends on 10) The circuit of claim 10 wherein the ceramic capacitor is a multi-layer ceramic capacitor. ### Claim 12 (depends on 7) The circuit of claim 7 further comprising a gate resistor providing a fixed resistance in series with the gate terminal, wherein the fixed resistance is configured to provide a predetermined switching time when the gate capacitor is at a highest temperature in the predetermined range of temperature.