Current source inverter control system and method

Abstract

A motor control system includes: a d-q target module configured to determine a first target d-axis current and a first target q-axis current based on a target torque of an electric motor; an offset module configured to determine a d-axis current offset and a q-axis current offset based on capacitor currents through capacitors connected across each phase of the electric motor; an adder module configured to determine a second target d-axis current based on the sum of the first target d-axis current and the d-axis current offset, and to determine a second target q-axis current based on the sum of the first target q-axis current and the q-axis current offset; and a driver module configured to switch a current source inverter (CSI) module based on the second target d-axis current and the second target q-axis current, the CSI module being configured to apply power to a phase of the electric motor.

Description

[0001] introduction

[0002] The information provided in this section is intended to provide a general overview of the background of this disclosure. To the extent described in this section, the work of the currently named inventors, and aspects of the description that may not conform to the prior art at the time of filing, are neither explicitly nor implicitly considered to be prior art to this disclosure. Technical Field

[0003] This disclosure relates to inverters for vehicle motors, and more particularly to current source inverters and systems and methods for controlling current source inverters. Background Technology

[0004] Some types of vehicles consist solely of an internal combustion engine that generates propulsive torque. Electric vehicles may not include an internal combustion engine and may rely on one or more electric motors for propulsion.

[0005] Hybrid electric vehicles (HEVs) include both an internal combustion engine and one or more electric motors. Some types of HEVs utilize both electric motors and an internal combustion engine to strive for greater fuel efficiency than would be achieved using only the internal combustion engine. Other types of HEVs utilize both electric motors and an internal combustion engine to achieve greater torque output than an internal combustion engine alone could provide.

[0006] Some examples of hybrid vehicle types include parallel hybrid vehicles, series hybrid vehicles, and other types. In a parallel hybrid vehicle, the electric motor works in parallel with the engine to combine the power and range advantages of the engine with the efficiency and regenerative braking advantages of the electric motor. In a series hybrid vehicle, the engine drives a generator to produce electricity for the electric motor, and the electric motor drives the transmission. This allows the electric motor to take on some of the power responsibilities of the engine, which may allow for the use of a smaller and potentially more efficient engine. Summary of the Invention

[0007] In one embodiment, a motor control system includes: a dq target module configured to determine a first target d-axis current and a first target q-axis current of an electric motor based on a target torque of the electric motor; an offset module configured to determine a d-axis current offset and a q-axis current offset based on capacitor currents through capacitors connected across each phase of the electric motor; an adder module configured to determine a second target d-axis current based on the sum of the first target d-axis current and the d-axis current offset, and to determine a second target q-axis current based on the sum of the first target q-axis current and the q-axis current offset; and a driver module configured to switch a current source inverter (CSI) module based on the second target d-axis current and the second target q-axis current, the current source inverter (CSI) module being configured to apply power to the phases of the electric motor.

[0008] In a further feature, the capacitor current module is configured to determine the capacitor current based on at least one of (a) the current input to the CSI module, (b) the speed of the electric motor, and (c) the modulation index of the CSI module.

[0009] In a further feature, a current sensor is used to measure the capacitor current.

[0010] In a further feature, the dq target module is configured to further determine the first target d-axis current and the first target q-axis current based on the speed of the electric motor.

[0011] In a further feature, the driver module is configured to switch the CSI module on and off based on the d-axis current and q-axis current of the electric motor.

[0012] In a further feature, the driver module is configured to switch the CSI module on and off based on (a) the difference between the d-axis current of the electric motor and the second target d-axis current and (b) the difference between the q-axis current of the electric motor and the second target q-axis current.

[0013] In a further feature, the second driver module is configured to switch the voltage-to-current converter module based on a first target d-axis current and a first target q-axis current, the voltage-to-current converter module being configured to output current to the CSI module based on the voltage from the battery.

[0014] In a further feature: the CSI target module is configured to determine the target current output from the voltage-to-current converter module to the CSI module based on the first d-axis current and the first q-axis current; and the second driver module is configured to switch the voltage-to-current converter module based on the target current.

[0015] In a further feature, the second driver module is configured to switch the voltage-current converter module based on the current output from the voltage-current converter module to the CSI module.

[0016] In a further feature, the second driver module is configured to switch the voltage-current converter module based on the difference between (a) the current output from the voltage-current converter module to the CSI module and (b) the target current output from the voltage-current converter module to the CSI module.

[0017] In a further feature, the capacitor is connected in parallel with the battery, and the voltage-to-current converter module is configured to convert the voltage from the capacitor into current and output the current to the CSI module.

[0018] In one feature, the motor control method includes: determining a first target d-axis current and a first target q-axis current of the electric motor based on a target torque of the electric motor; determining a d-axis current offset and a q-axis current offset based on capacitor currents through capacitors connected across each phase of the electric motor; determining a second target d-axis current based on the sum of the first target d-axis current and the d-axis current offset; determining a second target q-axis current based on the sum of the first target q-axis current and the q-axis current offset; and switching a current source inverter (CSI) module, the current source inverter (CSI) module being configured to apply power to a phase of the electric motor, based on the second target d-axis current and the second target q-axis current.

[0019] In a further feature, the motor control method also includes determining the capacitor current based on at least one of (a) the current input to the CSI module, (b) the speed of the electric motor, and (c) the modulation index of the CSI module.

[0020] In a further feature, the motor control method also includes using a current sensor to measure the capacitor current.

[0021] In a further feature, determining the first target d-axis current and the first target q-axis current includes further determining the first target d-axis current and the first target q-axis current based on the speed of the electric motor.

[0022] In a further feature, the switching of the CSI module includes switching the CSI module based on the d-axis current and the q-axis current of the electric motor.

[0023] In a further feature, switching the CSI module includes switching the CSI module based on (a) the difference between the d-axis current of the electric motor and the second target d-axis current and (b) the difference between the q-axis current of the electric motor and the second target q-axis current.

[0024] In a further feature, the motor control method also includes switching a voltage-to-current converter module based on a first target d-axis current and a first target q-axis current, the voltage-to-current converter module being configured to output current to the CSI module based on voltage from the battery.

[0025] In a further feature, the motor control method also includes: determining a target current output from the voltage-to-current converter module to the CSI module based on the first d-axis current and the first q-axis current; and switching the voltage-to-current converter module on and off based on the target current.

[0026] In a further feature, the switching of the voltage-to-current converter module includes switching the voltage-to-current converter module based on the current output from the voltage-to-current converter module to the CSI module.

[0027] This invention provides the following technical solutions:

[0028] 1. A motor control system, comprising:

[0029] The dq target module is configured to determine the first target d-axis current and the first target q-axis current of the electric motor based on the target torque of the electric motor.

[0030] The offset module is configured to determine the d-axis current offset and the q-axis current offset based on the capacitor currents of capacitors connected across each phase of the electric motor.

[0031] An adder module is configured to determine a second target d-axis current based on the sum of a first target d-axis current and a d-axis current offset, and to determine a second target q-axis current based on the sum of a first target q-axis current and a q-axis current offset; and

[0032] A driver module is configured to switch a current source inverter (CSI) module based on a second target d-axis current and a second target q-axis current, the current source inverter (CSI) module being configured to apply power to a phase of an electric motor.

[0033] The motor control system according to technical solution claim 1 further includes a capacitor current module, which is configured to determine the capacitor current based on at least one of (a) the current input to the CSI module, (b) the speed of the electric motor, and (c) the modulation index of the CSI module.

[0034] According to the motor control system described in technical solution 1, a current sensor is used to measure the capacitor current.

[0035] According to the motor control system of technical solution 1, the dq target module is configured to further determine the first target d-axis current and the first target q-axis current based on the speed of the motor.

[0036] According to the motor control system of technical solution 1, the driver module is configured to further switch the CSI module based on the d-axis current and the q-axis current of the motor.

[0037] According to the motor control system of technical solution 1, the driver module is configured to switch the CSI module based on (a) the difference between the d-axis current of the motor and the second target d-axis current and (b) the difference between the q-axis current of the motor and the second target q-axis current.

[0038] According to the motor control system of technical solution 1, it further includes a second driver module, which is configured to switch the voltage-to-current converter module based on the first target d-axis current and the first target q-axis current. The voltage-to-current converter module is configured to output current to the CSI module based on the voltage from the battery.

[0039] The motor control system according to technical solution 1 further includes:

[0040] The CSI target module is configured to determine the target current output from the voltage-to-current converter module to the CSI module based on a first d-axis current and a first q-axis current; and

[0041] The second driver module is configured to switch the voltage-to-current converter module based on the target current.

[0042] According to the motor control system of technical solution 8, the second driver module is configured to further switch the voltage-current converter module based on the current output from the voltage-current converter module to the CSI module.

[0043] According to the motor control system of technical solution 9, the second driver module is configured to switch the voltage-current converter module based on (a) the difference between the current output from the voltage-current converter module to the CSI module and (b) the target current output from the voltage-current converter module to the CSI module.

[0044] The motor control system according to technical solution 1 further includes:

[0045] Electric motor;

[0046] Battery;

[0047] A capacitor connected in parallel with the battery;

[0048] A voltage-to-current converter module configured to convert the voltage from the capacitor into current and output the current to the CSI module; and

[0049] CSI module.

[0050] A motor control method, comprising:

[0051] Based on the target torque of the electric motor, determine the first target d-axis current and the first target q-axis current of the electric motor.

[0052] The d-axis current offset and q-axis current offset are determined based on the capacitor currents through the capacitors connected across each phase of the electric motor.

[0053] The second target d-axis current is determined based on the sum of the first target d-axis current and the d-axis current offset;

[0054] The second target q-axis current is determined based on the sum of the first target q-axis current and the q-axis current offset; and

[0055] Based on the second target d-axis current and the second target q-axis current, the switch of the current source inverter (CSI) module, which is configured to apply power to the phase of the electric motor, is switched.

[0056] The motor control method according to technical solution 12 further includes determining the capacitor current based on at least one of (a) the current input to the CSI module, (b) the speed of the electric motor, and (c) the modulation index of the CSI module.

[0057] The motor control method according to technical solution 12 further includes using a current sensor to measure the capacitor current.

[0058] According to the motor control method of technical solution 12, determining the first target d-axis current and the first target q-axis current includes further determining the first target d-axis current and the first target q-axis current based on the speed of the electric motor.

[0059] According to the motor control method described in technical solution 12, switching the CSI module includes further switching the CSI module based on the d-axis current and the q-axis current of the electric motor.

[0060] According to the motor control method of technical solution 12, switching the CSI module includes switching the CSI module based on (a) the difference between the d-axis current of the motor and the second target d-axis current and (b) the difference between the q-axis current of the motor and the second target q-axis current.

[0061] The motor control method according to technical solution 12 further includes switching the voltage-to-current converter module based on the first target d-axis current and the first target q-axis current, wherein the voltage-to-current converter module is configured to output current to the CSI module based on the voltage from the battery.

[0062] The motor control method according to technical solution 12 further includes:

[0063] Based on the first d-axis current and the first q-axis current, determine the target current output from the voltage-to-current converter module to the CSI module; and

[0064] Based on the target current, switch the voltage-to-current converter module.

[0065] According to the motor control method of technical solution 19, switching the voltage-current converter module includes further switching the voltage-current converter module based on the current output from the voltage-current converter module to the CSI module.

[0066] Other areas of application of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0067] This disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0068] Figure 1 This is a functional block diagram of an example vehicle system;

[0069] Figure 2 This is a functional block diagram of an example propulsion control system;

[0070] Figure 3 Includes schematic diagrams of example implementations of a power control system;

[0071] Figure 4 A schematic diagram of an example implementation including a voltage-to-current converter module;

[0072] Figure 5 A schematic diagram of an example implementation including a current source inverter module;

[0073] Figure 6 A functional block diagram of an example implementation of a motor control module; and

[0074] Figure 7 This is a flowchart depicting an example method for controlling a voltage-to-current converter module and a current source inverter module.

[0075] In the accompanying drawings, reference numerals may be used repeatedly to identify similar and / or identical elements. Detailed Implementation

[0076] An inverter module for a vehicle includes a switching branch that regulates (a) the current from the battery to the electric motor and (b) the current from the electric motor to the battery. A direct current (DC) bus capacitor may be connected between the inverter module and the battery.

[0077] This application relates to a voltage-to-current converter module and a current source inverter (CSI) module. The CSI module regulates the current supplied to an electric motor. A control module controls the switching of the voltage-to-current converter module based on achieving a target current to the CSI module. The control module also controls the switching of the CSI module based on commands to achieve target d-axis and q-axis currents.

[0078] Now for reference Figure 1 A functional block diagram of an example vehicle system is presented. While a vehicle system for hybrid vehicles is shown and described, this disclosure is also applicable to electric vehicles (including pure electric vehicles) that do not include an internal combustion engine, fuel cell vehicles, autonomous vehicles, semi-autonomous vehicles, non-autonomous vehicles, and other types of vehicles. Furthermore, although vehicle examples are provided, this application is also applicable to non-vehicle implementations.

[0079] Engine 102 can combust an air / fuel mixture to produce drive torque. Engine control module (ECM) 114 controls engine 102. For example, ECM 114 can control the actuation of engine actuators such as throttle valve, one or more spark plugs, one or more fuel injectors, valve actuators, camshaft phase shifters, exhaust gas recirculation (EGR) valves, one or more turbochargers, and other suitable engine actuators. In some types of vehicles (e.g., electric vehicles), engine 102 may be omitted.

[0080] Engine 102 can output torque to transmission 195. Transmission control module (TCM) 194 controls the operation of transmission 195. For example, TCM 194 can control gear selection within transmission 195 and one or more torque transmission devices (e.g., torque converter, one or more clutches, etc.).

[0081] The vehicle system includes one or more electric motors, such as electric motor 198. The electric motor can act as a generator or a motor at any given time. When acting as a generator, the electric motor converts mechanical energy into electrical energy. The electrical energy can be used, for example, to charge battery 199. When acting as an electric motor, the electric motor generates torque that can be used, for example, to propel the vehicle. While an example of an electric motor is provided, a vehicle may include more than one electric motor.

[0082] Motor control module 196 controls the power flow from battery 199 to electric motor 198 and from electric motor 198 to battery 199. Motor control module 196 applies electrical power from battery 199 to electric motor 198 to cause electric motor 198 to output positive torque, such as for vehicle propulsion. Battery 199 may include, for example, one or more cells and / or a battery pack.

[0083] The electric motor 198 can output torque, for example, to the input shaft of the transmission 195 or to the output shaft of the transmission 195. The clutch 200 can be engaged to connect the electric motor 198 to the transmission 195 and disengaged to disconnect the electric motor 198 from the transmission 195. One or more gear transmissions can be implemented between the output of the clutch 200 and the input of the transmission 195 to provide a predetermined ratio between the rotation of the electric motor 198 and the rotation of the input of the transmission 195.

[0084] The motor control module 196 can also selectively convert the vehicle's mechanical energy into electrical energy. More specifically, when the electric motor 198 is driven by the transmission 195 and the electric motor control module 196 is not applying power from the battery 199 to the electric motor 198, the electric motor 198 generates and outputs power via reverse EMF. The motor control module 196 can charge the battery 199 using the power output by the electric motor 198.

[0085] Now for reference Figure 2The diagram presents a functional block diagram of an example propulsion control system. The driver torque module 204 determines a driver torque request 208 based on driver input 212. Driver input 212 may include, for example, accelerator pedal position (APP), brake pedal position (BPP), cruise control input, and / or autonomous input. In various embodiments, the cruise control input may be provided by an adaptive cruise control system that attempts to maintain at least a predetermined distance between the vehicle and objects in its path. Autonomous input may be provided by an autonomous driving system that controls the vehicle's movement from one location to another while avoiding objects and other vehicles. The driver torque module 204 may determine the driver torque request 208 using one or more lookup tables or equations that associate the driver input with the driver torque request. APP and BPP may be measured using one or more APP sensors and BPP sensors, respectively.

[0086] Driver torque request 208 can be an axle torque request. Axle torque (including axle torque requests) refers to the torque at the wheels. As discussed further below, propulsion torque (including propulsion torque requests) differs from axle torque because propulsion torque can refer to the torque at the transmission input shaft.

[0087] The axle torque arbitration module 216 arbitrates between the driver torque request 208 and other axle torque requests 220. Axle torque (torque at the wheels) can be generated from various sources, including the engine 102 and / or one or more electric motors, such as electric motor 198. Examples of other axle torque requests 220 include, but are not limited to, a torque reduction request from the traction control system when positive wheel slippage is detected, a torque increase request to counteract negative wheel slippage, a brake management request to reduce axle torque to ensure that the axle torque does not exceed the vehicle's ability to hold the vehicle when it stops, and a vehicle overspeed torque request to reduce axle torque to prevent the vehicle from exceeding a predetermined speed. The axle torque arbitration module 216 outputs one or more axle torque requests 224 based on the arbitration result between the received axle torque requests 208 and 220.

[0088] In a hybrid vehicle, the hybrid module 228 can determine how many of the one or more axle torque requests 224 should be generated by the engine 102, and how many of the one or more axle torque requests 224 should be generated by the electric motor 198. For simplicity, the example of electric motor 198 will continue, but multiple electric motors can be used. The hybrid module 228 outputs one or more engine torque requests 232 to the propulsion torque arbitration module 236. The engine torque requests 232 indicate the requested torque output of engine 102.

[0089] The hybrid module 228 also outputs a motor torque request 234 to the motor control module 196. The motor torque request 234 indicates the requested torque output (positive or negative) of the electric motor 198. In vehicles where the engine 102 is omitted (e.g., electric vehicles) or not connected to output propulsion torque for the vehicle, the axle torque arbitration module 216 may output an axle torque request, and the motor torque request 234 may be equal to that axle torque request. In the example of an electric vehicle, the ECM 114 may be omitted, and the driver torque module 204 and the axle torque arbitration module 216 may be implemented within the motor control module 196.

[0090] In electric vehicles, the driver torque module 204 can input the driver torque request 208 to the motor control module 196, and components related to controlling the engine actuator can be omitted.

[0091] The propulsion torque arbitration module 236 converts the engine torque request 232 from the axle torque domain (torque at the wheels) into the propulsion torque domain (e.g., torque at the transmission input shaft). The propulsion torque arbitration module 236 arbitrates the converted torque request against other propulsion torque requests 240. Examples of other propulsion torque requests 240 include, but are not limited to, torque reduction for engine overspeed protection requests and torque increase for stall prevention requests. The propulsion torque arbitration module 236 may output one or more propulsion torque requests 244 as the result of the arbitration.

[0092] Actuator control module 248 controls actuators 252 of engine 102 based on propulsion torque request 244. For example, based on propulsion torque request 244, actuator control module 248 can control throttle opening, spark timing from spark plugs, fuel timing and quantity injected by fuel injectors, cylinder actuation / deactivation, intake and exhaust valve phasing, output of one or more boosting devices (e.g., turbochargers, superchargers, etc.), EGR valve opening, and / or one or more other engine actuators. In various embodiments, propulsion torque request 244 can be adjusted or modified before being used by actuator control module 248, such as to generate torque reserves.

[0093] The motor control module 196 controls the switching of the voltage-to-current (V / I) converter module and the current source inverter (CSI) module based on the motor torque request 234, as discussed further below. The switching of the V / I converter module controls the current to the CSI module. The switching of the CSI module controls the current to the electric motor 198. In this way, the switching of the CSI module controls the torque of the electric motor 198. The CSI module also converts the power generated by the electric motor 198 and outputs power for the battery 199 (e.g., to charge the battery 199).

[0094] The CSI module includes multiple switches. The motor control module toggles the switches to apply alternating current (AC) power to the electric motor 198 to drive it. For example, the CSI module may generate n-phase AC power and apply it to n stator windings of the electric motor 198 (e.g., a, b, and c, or u, v, and w). In various embodiments, n equals 3. The rotor of the electric motor 198 is driven by the magnetic flux generated by the current flowing through the stator windings. The rotor is connected to and drives the output shaft of the electric motor 198 to rotate. The output shaft of the electric motor 198 is connected to one or more wheels of the vehicle.

[0095] In various implementations, one or more filters (e.g., capacitors) may be electrically connected between the inverter module and the battery 199. These filters may be implemented, for example, to filter the power flow into and out of the battery 199. As an example, a filter comprising one or more capacitors and resistors may be electrically connected in parallel with the battery 199.

[0096] Figure 3 This includes a schematic diagram of an example implementation containing a power control system. As described above, battery 199 may also be referred to as or include a battery pack.

[0097] The high (positive, DC+) and low (negative, DC-) sides 304 and 308 are connected to the positive and negative terminals of the battery 199, respectively. One or more capacitors (such as capacitor 312) are connected in parallel with the battery 199 between the high side 304 and the low side 308. The capacitors filter the power flow into and out of the battery 199.

[0098] The voltage-to-current (V / I) converter module 316 converts the voltage from the high side 304 and the low side 308 into a current source inverter (CSI) current 320. The V / I converter module 316 supplies the CSI current 320 to the current source inverter (CSI) module 324 via the second high side 328 and the low side 332.

[0099] CSI module 324 includes three branches, one of which is connected to one phase of motor 198. CSI module 324 controls the current to the branch / phase of motor 198. Capacitors 336-1, 336-2, and 336-3 are connected between the corresponding one in the branch and the common node 340.

[0100] Figure 4 A schematic diagram of an example embodiment including V / I converter module 316. The cathode of the first diode 404 is connected to the high side 304, and the anode of the first diode 404 is connected to the first node 408. The first node 408 is connected to the second low side 332.

[0101] The first terminal of the first switch 412 is connected to the first node 408. The second terminal of the first switch 412 is connected to the low side 308. The second diode 416 is connected in anti-parallel to the first switch 412. In other words, the cathode of the second diode 416 is connected to the first terminal of the first switch 412, and the anode of the second diode 416 is connected to the second terminal of the first switch 412.

[0102] The first terminal of the second switch 420 is connected to the high side 304. The second terminal of the second switch 420 is connected to the second node 424. The third diode 428 is connected in anti-parallel to the second switch 420. In other words, the cathode of the third diode 428 is connected to the first terminal of the second switch 420, and the anode of the third diode 428 is connected to the second terminal of the second switch 420.

[0103] The cathode of the fourth diode 432 is connected to the second node 424, and the anode of the first diode 404 is connected to the low side 332. The first terminal of the inductor 436 is connected to the second node 424, and the second terminal of the inductor 436 is connected to the second high side 328. The V / I converter module 316 outputs the CSI voltage to the SiC module 324.

[0104] The control terminals of the first and second switches 412 and 420 are connected to the V / I switch signal 440. When the V / I switch signal 440 is in a first state, the first and second switches 412 and 420 are closed. When the V / I switch signal 440 is in a second state, the first and second switches 412 and 420 are open. The motor control module 196 generates the V / I switch signal 440, as discussed further below.

[0105] Each of the first and second switches 412 and 420 can be an insulated-gate bipolar transistor (IGBT), a field-effect transistor (FET) (such as a metal-oxide-semiconductor FET (MOSFET)), or another suitable type of switch. In the example of IGBT and FET, the control terminal is referred to as the gate.

[0106] Figure 5 This is a schematic diagram of an example implementation of CSI module 324. CSI module 324 includes three branches. One branch is connected to each phase of electric motor 198.

[0107] The first branch 512 includes first and second switches 516 and 520. Switches 516 and 520 each include a first terminal, a second terminal, and a control terminal. Each of switches 516 and 520 can be an insulated-gate bipolar transistor (IGBT), a field-effect transistor (FET) such as a metal-oxide-semiconductor FET (MOSFET), or another suitable type of switch. In the example of IGBTs and FETs, the control terminal is referred to as the gate.

[0108] The first terminal of the first switch 516 is connected to the second high side 328. The second terminal of the first switch 516 is connected to node 504 via diode 508. In various embodiments, a bidirectional or reverse voltage blocking switch can be used, and diode 508 can be omitted. The second terminal of the second switch 520 can be connected to the second low side 332. Node 504 is connected to the second terminal of the first switch 516, and the first terminal of the second switch 520 is connected to the first phase (e.g., a) of the electric motor 198.

[0109] The first branch 512 may include first and second diodes 524 and 528, respectively, connected in anti-parallel to switches 516 and 520. In other words, the anode of the first diode 524 may be connected to the second terminal of the first switch 516, and the cathode of the first diode 524 may be connected to the first terminal of the first switch 516. The anode of the second diode 528 may be connected to the second terminal of the second switch 520, and the cathode of the second diode 528 may be connected to the first terminal of the second switch 520. Diodes 524 and 528 form one phase of a three-phase rectifier. However, diodes 524 and 528 may be omitted. Diodes 524 and 528 may be included if they are included in the power module of the IGBT.

[0110] CSI module 324 also includes second and third branches 532 and 536. The second and third branches 532 and 536 may (in terms of circuitry) be similar to or identical to the first branch 512. In other words, the second and third branches 532 and 536 may each include corresponding switches and diodes, such as switches 516 and 520 and diodes 508, 524, and 528, which are connected in the same manner as the first branch 512. For example, the second branch 532 includes switches 540 and 544 and anti-parallel diodes 548 and 552. Node 542 connected to diode 543 and the first terminal of switch 544 are connected to the second stator winding of electric motor 198 (e.g., b). The third branch 536 includes switches 556 and 560, diode 562, and anti-parallel diodes 564 and 568. Node 570 connected to diode 562 and the first terminal of switch 560 are connected to the third stator winding of electric motor 198 (e.g., c). Similar to diodes 524 and 528, diodes 548, 552, 564, and 568 can be omitted. Diodes 543 and 562 can also be omitted.

[0111] Capacitors 336-1, 336-2, and 336-3 are connected as shown in the figure. Capacitor current 572 flows through capacitors 336-1, 336-2, and 336-3. As described below, a current sensor can measure or estimate the capacitor current 572.

[0112] The control terminals of the switches in CSI module 324 are connected to CSI switch signals 576 from motor control module 196. At any given time, at least one high-side switch of the branch and at least one low-side switch of the branch are on. Motor control module 196 determines when each switch is on and for how long, and generates CSI switch signals 576 accordingly.

[0113] Figure 6 This is a functional block diagram of an example implementation of the motor control module 196. The target torque module 604 determines a target torque 608 based on the motor torque request 234. For example, the target torque module 604 can determine the target torque 608 using either an equation or a lookup table that associates the torque request with the target torque.

[0114] The dq target module 612 determines the initial target d-axis current and initial target q-axis current (collectively represented by 616) of the electric motor 198 based on the target torque 608 and speed 618 (motor speed) of the electric motor 198. The speed 618 of the electric motor 198 can be measured using a sensor or estimated based on one or more parameters, such as the current to the phase of the electric motor 198. The dq target module 612 can determine the initial target d-axis and q-axis currents 616 using one or more equations or lookup tables that correlate the target torque and motor speed with the d-axis and q-axis currents.

[0115] The CSI target module 620 determines the target CSI current 624 based on the initial target d-axis and q-axis currents 616. The CSI target module 620 can determine the target CSI current 624 using one or more equations or lookup tables that associate the target d-axis and q-axis currents with the target CSI current. The target CSI current 624 is the target value of the CSI current 320.

[0116] Error module 628 determines error 632 based on the difference between target CSI current 624 and CSI current 320. Error module 628 can set error 632 based on or equal to target CSI current 624 minus CSI current 320 or based on or equal to CSI current 320 minus target CSI current 624.

[0117] Closed-loop module 636 adjusts the modulation index (MI) 644 of V / I converter module 316 based on error 632. For example, closed-loop module 636 can adjust MI 640 to bring error 632 toward or to zero. Closed-loop module 636 may include, for example, a proportional-integral (PI) control module or another suitable type of closed-loop control. Closed-loop module 636 can further adjust MI 640 based on the input voltage 644 to V / I converter module 316. Input voltage 644 is the voltage across high-side 304 and low-side 308.

[0118] The driver module 648 generates V / I switching signals 440 based on MI 640, such as to implement MI 640.

[0119] The capacitor current module 652 determines the capacitor current 656 based on the motor speed 618, the MI 660 of the CSI module 324, and the CSI current 320. The capacitor current module 652 can determine the capacitor current 656, for example, using one or more equations and / or lookup tables that correlate the motor speed, MI, and CSI current with the capacitor current. The capacitor current 656 is an estimate of the capacitor current 572. In various embodiments, the capacitor current module 652 may be omitted, and the capacitor current 572 may be measured and used instead of the capacitor current 656.

[0120] Offset module 664 determines the d-axis and q-axis current offsets 668 based on the capacitor current 656. Offset module 664 can determine the d-axis and q-axis current offsets 668 using equations or lookup tables that correlate the capacitor current with the d-axis and q-axis current offsets. The d-axis and q-axis current offsets 668 can be the same or different values.

[0121] Adder module 672 adds the d-axis and q-axis current offsets 668 to the initial target d-axis and q-axis currents 616 to determine the final target d-axis and q-axis currents 676 of motor 198, respectively. For example, adder module 672 can set the final target d-axis current to the initial target d-axis current plus the d-axis current offset. Adder module 672 can set the final target q-axis current to the initial target q-axis current plus the q-axis current offset. In other words, the d-axis and q-axis currents output by dq target module 612 plus the capacitor d-axis and q-axis currents equal the motor d-axis and q-axis currents.

[0122] Duty cycle module 680 generates duty cycles 684 for the branches of CSI module 324 based on the difference between the final target d-axis and q-axis currents 676 and the current d-axis and q-axis currents 686. Duty cycle module 680 can generate the duty cycle, for example, using an equation or lookup table that correlates the final d-axis and q-axis currents with the duty cycle. The current d-axis and q-axis currents 686 can be determined, for example, based on the phase currents to motor 198. The duty cycle for each branch may be the same. Duty cycle module 680 uses pulse width modulation (PWM) control to generate duty cycle 684.

[0123] The driver module 688 generates CSI switching signals 576 for the branch switches based on a duty cycle 684. As described above, the switches in each branch are controlled complementaryly, such that when one switch in a branch is closed, the other switch in the branch is open. However, both switches in each branch can be open simultaneously. However, the phase of each branch can be approximately 120 degrees apart, as set by the CSI switching signal 576.

[0124] Figure 7 This is a flowchart depicting an example method of controlling the V / I converter module 316 and the CSI module 324. Control begins at 704, where the torque target module 604 determines a target torque 608 based on the motor torque request 234. At 708, the dq target module 612 determines initial target d-axis and q-axis currents 616 based on the target torque 608.

[0125] At 712, the CSI target module 620 determines the target CSI current 624 input to the CSI module 324 based on the initial target d-axis and q-axis 616. At 716, the error module 628 determines the error 632 based on the target CSI current 624 and the CSI current 320. At 720, the closed-loop module 636 determines the MI 640 for the V / I converter module 316 based on the error 632, such as adjusting the error 632 towards or to zero.

[0126] At 724, capacitor current module 652 determines capacitor current 656 based on MI CSI 660 and CSI current 320, or measures capacitor current 656 using a current sensor. At 724, offset module 664 determines d-axis and q-axis capacitor current offsets 608 based on capacitor current 656. As mentioned above, capacitor current 656 can be measured using a sensor or estimated using capacitor current module 652. At 728, adder module 672 determines final target d-axis and q-axis currents 676 based on the sum of initial target d-axis and q-axis currents 628 and offset 608, respectively.

[0127] At 732, the duty cycle module 680 determines the duty cycle 684 of the CSI module 324's switch based on the final target d-axis and q-axis currents 676 and 686. At 736, the driver module 648 switches the V / I converter module 316 based on MI 640, and the driver module 688 switches the CSI module 324's switch based on the duty cycle 684. Although Figure 7 The example is shown as the end, but control can return to 704 for the next control loop.

[0128] The above description is illustrative in nature and is in no way intended to limit this disclosure, its application, or its use. The broad teachings of this disclosure can be implemented in many forms. Therefore, while this disclosure includes specific examples, its true scope should not be limited thereto, as other modifications will become apparent upon examination of the drawings, specification, and the following claims. It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, while each of the embodiments described above is described as having certain features, any one or more of those features described with respect to any embodiment of this disclosure may be implemented in and / or combined with features of any other embodiment, even if such combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitutions of one or more embodiments for each other remain within the scope of this disclosure.

[0129] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including “connection,” “joint,” “link,” “adjacent,” “close to,” “on top of,” “above,” “below,” and “set.” Unless explicitly described as “direct,” when describing a relationship between a first element and a second element in the above disclosure, the relationship can be a direct relationship in which no other intervening element exists between the first element and the second element, but it can also be an indirect relationship in which one or more intervening elements exist between the first element and the second element (whether spatially or functionally). As used herein, at least one of the phrases A, B, and C should be interpreted as meaning the use of the non-exclusive logic “OR” (A or B or C), and should not be interpreted as “at least one of A, at least one of B, and at least one of C.”

[0130] In a view, the direction of the arrows generally indicates the flow of information of interest, such as data or instructions. For example, when components A and B exchange various types of information, but the information transmitted from component A to component B is relevant to the illustration, the arrow may point from component A to component B. This unidirectional arrow does not imply the absence of other information transmitted from component B to component A. Furthermore, for information sent from component A to component B, component B may send a request for that information or an acknowledgment of receipt of that information to component A.

[0131] In this application, which includes the following definitions, the term "module" or "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include the following: application-specific integrated circuit (ASIC); digital, analog, or mixed analog / digital discrete circuit; digital, analog, or mixed analog / digital integrated circuit; combinational logic circuit; field-programmable gate array (FPGA); processor circuitry (shared, dedicated, or grouped) that executes code; memory circuitry (shared, dedicated, or grouped) that stores code executed by the processor circuitry; other suitable hardware components that provide the described functionality; or some or all of the above, such as in a system-on-a-chip.

[0132] A module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module in this disclosure may be distributed among multiple modules connected via interface circuits. For example, multiple modules may allow for load balancing. In a further example, a server (also known as a remote server or cloud server) module may perform certain functions on behalf of a client module.

[0133] As used above, the term "code" can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuitry" covers a single processor circuitry that executes some or all of the code from multiple modules. The term "grouped processor circuitry" covers processor circuitry that, in conjunction with additional processor circuitry, executes some or all of the code from one or more modules. The term "multiple processor circuitry" refers to multiple processor circuitry on a discrete die, multiple processor circuitry on a single die, multiple cores of a single processor circuitry, multiple threads of a single processor circuitry, or a combination of the above. The term "shared memory circuitry" covers a single memory circuitry that stores some or all of the code from multiple modules. The term "grouped memory circuitry" covers memory circuitry that, in conjunction with additional memory, stores some or all of the code from one or more modules.

[0134] The term memory circuit is a subset of the term computer-readable medium. As used herein, the term computer-readable medium does not cover transient electrical or electromagnetic signals propagating through a medium (such as on a carrier wave); the term computer-readable medium can therefore be considered tangible and non-transient. Non-limiting examples of non-transient tangible computer-readable media include: non-volatile memory circuits (such as flash memory circuits, erasable programmable read-only memory circuits, or masked read-only memory circuits), volatile memory circuits (such as static random access memory circuits or dynamic random access memory circuits), magnetic storage media (such as analog or digital magnetic tape or hard disk drives), and optical storage media (such as CDs, DVDs, or Blu-ray discs).

[0135] The apparatus and methods described in this application can be implemented, in part or in whole, by a dedicated computer created by configuring a general-purpose computer to perform one or more specific functions embodied in a computer program. The function blocks, flowchart components, and other elements described above serve as software specifications that can be translated into a computer program by the ordinary work of a person skilled in the art or a programmer.

[0136] A computer program includes processor-executable instructions stored on at least one non-transitory, tangible, computer-readable medium. A computer program may also include or depend on stored data. A computer program may encompass a basic input / output system (BIOS) that interacts with the hardware of a special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0137] Computer programs may include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Notation); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code for execution by an interpreter; and (v) source code for compilation and execution by a just-in-time (JIT) compiler, etc. As an example only, source code may be written using syntax from languages ​​including: C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, and Java. ® , Fortran, Perl, Pascal, Curl, OCaml, Javascript ® HTML5 (Hypertext Markup Language 5th Edition), Ada, ASP (Dynamic Server Web Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash ®, Visual Basic ® , Lua, MATLAB, SIMULINK, and Python ® .

Claims

1. A motor control system, comprising: The dq target module is configured to determine the first target d-axis current and the first target q-axis current of the electric motor based on the target torque of the electric motor. The offset module is configured to determine the d-axis current offset and the q-axis current offset based on the capacitor currents of capacitors connected across each phase of the electric motor. An adder module is configured to determine a second target d-axis current based on the sum of a first target d-axis current and a d-axis current offset, and to determine a second target q-axis current based on the sum of a first target q-axis current and a q-axis current offset. and A driver module is configured to switch a current source inverter module based on a second target d-axis current and a second target q-axis current, the current source inverter module being configured to apply power to a phase of an electric motor.

2. The motor control system of claim 1 further includes a capacitor current module configured to determine the capacitor current based on at least one of (a) the current input to the current source inverter module, (b) the speed of the electric motor, and (c) the modulation index of the current source inverter module.

3. The motor control system according to claim 1, wherein, Use a current sensor to measure the capacitor current.

4. The motor control system according to claim 1, wherein, The dq target module is configured to further determine the first target d-axis current and the first target q-axis current based on the speed of the electric motor.

5. The motor control system according to claim 1, wherein, The driver module is configured to further switch the current source inverter module based on the d-axis current and the q-axis current of the electric motor.

6. The motor control system according to claim 1, wherein, The driver module is configured to switch the current source inverter module on and off based on (a) the difference between the d-axis current of the electric motor and the second target d-axis current and (b) the difference between the q-axis current of the electric motor and the second target q-axis current.

7. The motor control system according to claim 1 further includes a second driver module, the second driver module being configured to switch the voltage-to-current converter module based on the first target d-axis current and the first target q-axis current, the voltage-to-current converter module being configured to output current to the current source inverter module based on the voltage from the battery.

8. The motor control system according to claim 1, further comprising: A current source inverter target module is configured to determine the target current output from the voltage-to-current converter module to the current source inverter module based on the first d-axis current and the first q-axis current. and The second driver module is configured to switch the voltage-to-current converter module based on the target current.

9. The motor control system according to claim 8, wherein, The second driver module is configured to further switch the voltage-current converter module based on the current output from the voltage-current converter module to the current source inverter module.

10. The motor control system according to claim 9, wherein, The second driver module is configured to switch the voltage-current converter module based on (a) the difference between the current output from the voltage-current converter module to the current source inverter module and (b) the target current output from the voltage-current converter module to the current source inverter module.

11. The motor control system according to claim 1, further comprising: Electric motor; Battery; A capacitor connected in parallel with the battery; A voltage-to-current converter module is configured to convert the voltage from the capacitor into current and output the current to the current source inverter module; and Current source inverter module.

12. A motor control method, comprising: Based on the target torque of the electric motor, determine the first target d-axis current and the first target q-axis current of the electric motor. The d-axis current offset and q-axis current offset are determined based on the capacitor currents through the capacitors connected across each phase of the electric motor. The second target d-axis current is determined based on the sum of the first target d-axis current and the d-axis current offset; The second target q-axis current is determined based on the sum of the first target q-axis current and the q-axis current offset; and Based on the second target d-axis current and the second target q-axis current, the switch of the current source inverter module configured to apply power to the phase of the electric motor is switched.

13. The motor control method of claim 12, further comprising determining the capacitor current based on at least one of (a) the current input to the current source inverter module, (b) the speed of the electric motor, and (c) the modulation index of the current source inverter module.

14. The motor control method according to claim 12 further includes using a current sensor to measure the capacitor current.

15. The motor control method according to claim 12, wherein, Determining the first target d-axis current and the first target q-axis current includes further determining the first target d-axis current and the first target q-axis current based on the speed of the electric motor.

16. The motor control method according to claim 12, wherein, Switching the current source inverter module includes further switching the current source inverter module based on the d-axis current and the q-axis current of the electric motor.

17. The motor control method according to claim 12, wherein, Switching the current source inverter module includes switching the current source inverter module based on (a) the difference between the d-axis current of the electric motor and the second target d-axis current and (b) the difference between the q-axis current of the electric motor and the second target q-axis current.

18. The motor control method according to claim 12 further includes switching a voltage-to-current converter module based on the first target d-axis current and the first target q-axis current, the voltage-to-current converter module being configured to output current to the current source inverter module based on the voltage from the battery.

19. The motor control method according to claim 12, further comprising: Based on the first d-axis current and the first q-axis current, the target current output from the voltage-to-current converter module to the current source inverter module is determined. and The voltage-to-current converter module is switched on and off based on the target current.

20. The motor control method according to claim 19, wherein, Switching the voltage-to-current converter module includes further switching the voltage-to-current converter module based on the current output from the voltage-to-current converter module to the current source inverter module.

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