Control of active commutation in wireless power systems

Abstract

To provide control of active commutation in a preferred wireless power system. [Solution] Described herein are active rectification methods and systems for a rectifier in a wireless power system. An example method can include detecting one or more zero crossings of a current at an input of the rectifier with a zero crossing detector and determining a first delay time based on at least one wireless power system parameter and the zero crossings. The method can also include generating first and second control signals for a first and second switch of the rectifier, respectively, based on the first delay time, inserting a first dead time between the first and second control signals, and providing the first and second control signals to the first and second switches, respectively.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to and the benefit of U.S. Provisional Patent Application No. 62 / 891,959, entitled “CONTROL OF ACTIVE RECTIFIER SWITCHES IN WIRELESS POWER SYSTEMS,” filed August 26, 2019, which is hereby incorporated by reference in its entirety.

[0002] The following disclosure relates to active rectification methods and systems for wireless power systems, and more particularly to control of active rectification methods and systems for wireless power receivers. [Background technology]

[0003] Wireless power systems are configured to transmit power to a load (e.g., a battery of an electrical device) without mechanical contact between the transmitter and receiver. The wireless power receiver of such a system generally includes a rectifier to convert vibrational energy to DC for delivery to a load (e.g., a battery) coupled to the receiver. It can be beneficial for the rectifier to operate with high efficiency. Summary of the Invention [Problem to be solved by the invention]

[0004] Disclosed herein is a control method for active commutation for wireless power systems. [Means for solving the problem]

[0005] In one aspect, the disclosure features an active rectification method for a rectifier of a wireless power system. The method may include detecting one or more zero crossings of a current at an input of the rectifier by a zero crossing detector and determining a first delay time based on at least one wireless power system parameter and the zero crossing. The method may further include generating first and second control signals for a first and second switch of the rectifier, respectively, based on the first delay time, inserting a first dead time between the first and second control signals, and providing the first and second control signals to the first and second switches, respectively.

[0006] Various embodiments of the active rectification method may include one or more of the following features. The method may include determining a second delay time based on a wireless power system parameter and a zero crossing, generating a third control signal and a fourth control signal for a third switch and a fourth switch of the rectifier, respectively, based on the second delay time, inserting a second dead time between the third control signal and the fourth control signal, and providing the third control signal and the fourth control signal to the third rectifier switch and the fourth rectifier switch, respectively. The third switch and the fourth switch may be coupled to the first switch and the second switch in a full-bridge configuration. The rectifier may be part of a wireless power receiver. The rectifier may be part of a wireless power transmitter.

[0007] The rectifier may include two diodes coupled in a full-bridge rectifier configuration with a first switch and a second switch. The first switch and the second switch may be low-side switches of the rectifier. The first switch and the second switch may be coupled to a first rectifier input, and the two diodes are coupled to a second rectifier input. The first delay time may be determined by a delay block operably coupled to the zero-crossing detector. The zero-crossing may include a first zero-crossing corresponding to a rising edge of the current and a second zero-crossing corresponding to a falling edge of the current. The value of the at least one wireless power system parameter may be based on at least one of (i) an impedance of the rectifier, (ii) a power level delivered to a load coupled to the wireless power system, or (iii) a coil current of a wireless power receiver including the rectifier.

[0008] In another aspect, the disclosure features an active rectification system for a wireless power system. The system may include a first switch and a second switch coupled between an oscillating current source of the wireless power system and a battery, and a control system coupled to each of the first switch and the second switch. The control system may be configured to detect one or more zero crossings of the oscillating current at an input of the rectifier and determine a first delay time based on at least one wireless power system parameter and the zero crossing. The control system may be further configured to generate a first control signal and a second control signal for the first switch and the second switch of the rectifier, respectively, based on the first delay time, insert a first dead time between the first control signal and the second control signal, and provide the first control signal and the second control signal to the first switch and the second switch, respectively.

[0009] Various embodiments of the active rectification system may include one or more of the following features. The system may include a third switch and a fourth switch coupled between an oscillating current source of the wireless power system and a battery. The control system may be further configured to determine a second delay time based on the wireless power system parameters and the zero crossings, and generate third and fourth control signals for the third and fourth switches of the rectifier, respectively, based on the second delay time. The control system may be further configured to insert a second dead time between the third and fourth control signals, and provide the third and fourth control signals to the third and fourth rectifier switches, respectively. The third and fourth switches may be coupled to the first and second switches and are in a full-bridge configuration.

[0010] The rectifier may be part of the wireless power receiver. The rectifier may be part of the wireless power transmitter. The rectifier may include two diodes coupled in a full-bridge rectifier configuration with a first switch and a second switch. The first switch and the second switch may be low-side switches of the rectifier. The value of the at least one wireless power system parameter may be based on at least one of (i) an impedance of the rectifier, (ii) a power level transferred to a battery coupled to the wireless power system, or (iii) a coil current of a wireless power receiver including the rectifier.

[0011] In another aspect, this disclosure features an active rectification method for a wireless power system. The method can include detecting one or more zero crossings of a current at an input of a rectifier with a zero crossing detector, generating a phase-locked loop (PLL) signal based on a rising zero crossing and a falling zero crossing, determining a first delay time based on at least one wireless power system parameter and the zero crossing, generating first and second control signals for a first and second switch of the rectifier, respectively, based on the first delay time and the PLL signal, inserting a first dead time between the first and second control signals, and providing the first and second control signals to the first and second switches, respectively.

[0012] In another aspect, this disclosure features an active rectification method for a wireless power system. The method can include receiving and / or filtering a current at an input of a rectifier, detecting one or more zero crossings of the current at the input of the rectifier with a zero crossing detector, determining a first delay time based on at least one wireless power system parameter and the zero crossings, generating first and second control signals for a first and second switch of the rectifier, respectively, based on the first delay time, inserting a first dead time between the first and second control signals, and providing the first and second control signals to the first and second switches, respectively.

[0013] In another aspect, this disclosure features an active rectification method for a wireless power system. The method can include detecting one or more zero crossings of a current at an input of a rectifier by a zero crossing detector, generating a phase-locked loop (PLL) signal based on a rising zero crossing and a falling zero crossing, determining a first voltage signal based on one or more wireless power system parameters, generating first and second control signals for a first and second switch of the rectifier, respectively, based on the PLL signal and the first voltage signal, inserting a first dead time between the first and second control signals, and providing the first and second control signals to the first and second switches, respectively. The present specification also provides, for example, the following items: (Item 1) 1. An active rectification method for a rectifier in a wireless power system, comprising: detecting one or more zero crossings of a current at an input of the rectifier with a zero crossing detector; determining a first delay time based on at least one wireless power system parameter and the zero crossing; generating a first control signal and a second control signal for a first switch and a second switch of the rectifier, respectively, based on the first delay time; Inserting a first dead time between the first control signal and the second control signal; providing the first control signal and the second control signal to the first switch and the second switch, respectively; The active commutation method includes: (Item 2) determining a second delay time based on the wireless power system parameters and the zero crossings; generating third and fourth control signals for a third and fourth switch of the rectifier, respectively, based on the second delay time; Inserting a second dead time between the third control signal and the fourth control signal; providing the third control signal and the fourth control signal to the third rectifier switch and the fourth rectifier switch, respectively; The method of claim 1, further comprising: (Item 3) 3. The method of claim 2, wherein the third switch and the fourth switch are coupled to the first switch and the second switch in a full-bridge configuration. (Item 4) 2. The method of claim 1, wherein the rectifier is part of a wireless power receiver. (Item 5) Item 10. The method of item 1, wherein the rectifier is part of a wireless power transmitter. (Item 6) 2. The method of claim 1, wherein the rectifier includes two diodes coupled in a full-bridge rectifier configuration with the first switch and the second switch. (Item 7) 7. The method of claim 6, wherein the first switch and the second switch are low-side switches of the rectifier. (Item 8) 7. The method of claim 6, wherein the first switch and the second switch are coupled to a first rectifier input, and the two diodes are coupled to a second rectifier input. (Item 9) 2. The method of claim 1, wherein the first delay time is determined by a delay block operatively coupled to the zero-crossing detector. (Item 10) 2. The method of claim 1, wherein the zero crossings include a first zero crossing corresponding to a rising edge of the current and a second zero crossing corresponding to a falling edge of the current. (Item 11) The value of the at least one wireless power system parameter is: (i) the impedance of the rectifier; (ii) the power level delivered to a load coupled to the wireless power system; or (iii) a coil current of a wireless power receiver having the rectifier The method according to item 1, wherein the method is based on at least one of the following: (Item 13) 1. An active rectification system for a wireless power system, the system comprising: a first switch and a second switch coupled between an oscillating current source and a battery of the wireless power system; a control system coupled to each of the first switch and the second switch; The control system comprises: detecting one or more zero crossings of the oscillating current at an input of the rectifier; determining a first delay time based on at least one wireless power system parameter and the zero crossing; generating a first control signal and a second control signal for the first switch and the second switch of the rectifier, respectively, based on the first delay time; inserting a first dead time between the first control signal and the second control signal; providing the first control signal and the second control signal to the first switch and the second switch, respectively; The active rectification system is configured as follows: (Item 14) a third switch and a fourth switch coupled between the oscillating current source and the battery of the wireless power system; The control system includes: determining a second delay time based on the wireless power system parameters and the zero crossing; generating third and fourth control signals for a third and fourth switch of the rectifier based on the second delay time; A second dead time is inserted between the third control signal and the fourth control signal; providing the third control signal and the fourth control signal to the third rectifier switch and the fourth rectifier switch, respectively; Item 14. The system of item 13, further configured as follows: (Item 15) Item 15. The system of item 14, wherein the third switch and the fourth switch are coupled to the first switch and the second switch in a full-bridge configuration. (Item 16) Item 14. The system of item 13, wherein the rectifier is part of a wireless power receiver. (Item 17) Item 14. The system of item 13, wherein the rectifier is part of a wireless power transmitter. (Item 18) Item 14. The system of item 13, wherein the rectifier includes two diodes coupled in a full-bridge rectifier configuration with the first switch and the second switch. (Item 19) 20. The system of claim 18, wherein the first switch and the second switch are low-side switches of the rectifier. (Item 20) The value of the at least one wireless power system parameter is: (i) the impedance of the rectifier; (ii) the level of power delivered to the battery coupled to the wireless power system; or (iii) a coil current of a wireless power receiver having the rectifier Item 14. The system according to item 13, based on at least one of the following: [Brief description of the drawings]

[0014] [Figure 1] 1 is a block diagram of an example wireless power system. [Figure 2A] 1 is a schematic diagram of an example wireless power system employing active rectification. [Figure 2B] 2B-2C are schematic diagrams of an exemplary wireless power receiver employing active rectification. [Figure 2C] 2B-2C are schematic diagrams of an exemplary wireless power receiver employing active rectification. [Figure 3A] 1 is a schematic diagram of an example wireless power system employing active rectification. [Figure 3B] FIG. 1 illustrates an example workflow for determining control signals for rectifier switches based on input current. [Figure 3C] 1 is a set of plots showing various signals in the generation of a control signal as a function of time. [Figure 3D] 4 is a flowchart of an example method for rectifier switch control in a wireless power system. [Figure 4A] 1 illustrates an example workflow for determining control signals for rectifier switches based on input current. [Figure 4B] 1 is a set of plots showing various signals in the generation of a control signal as a function of time. [Figure 4C] 4 is a flowchart of an example method for rectifier switch control in a wireless power system. [Figure 5A] FIG. 1 illustrates an example workflow for generating control signals for rectifier switches based on input current. [Figure 5B] 1 is a set of plots showing various signals in the generation of a control signal as a function of time. [Figure 5C] 4 is a flowchart of an example method for rectifier switch control in a wireless power system. [Figure 6A] FIG. 1 illustrates an example workflow for determining control signals for rectifier switches based on input current and input voltage. [Figure 6B] 1 is a set of plots showing various signals in the generation of a control signal as a function of time. [Figure 6C] 4 is a flowchart of an example method for rectifier switch control in a wireless power system. [Figure 6D] No description [Figure 7]1 is a schematic diagram of an exemplary bidirectional wireless power transmission system. [Figure 8] 1 is a flow chart of an exemplary interactive control process. [Figure 9] 1 is a schematic diagram of an example inverter rectifier and a timing diagram illustrating the operation of the inverter rectifier in an inverter mode of operation. [Figure 10] 2A-2C are schematic diagrams of an example inverter rectifier and timing diagrams illustrating operation of the inverter rectifier in a rectifier mode of operation. [Figure 11] FIG. 1 is a block diagram of an example computer system that may be used in implementing the active rectification systems and methods described herein. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] Disclosed herein are exemplary embodiments of active rectification systems and methods in wireless power systems. In particular, active rectification may be used in wireless power receivers. Active rectification employs actively controlled switches coupled to form a rectifier. The switches may include transistors (e.g., FETs, MOSFETs, BJTs, IGBTs, etc.). In an exemplary wireless power system, the active rectifier may be used to convert an oscillating current (AC) received at a wireless power receiver to a direct current (DC), which may be used to ultimately transfer energy to a load, as further described below. Details of the exemplary embodiments are discussed below.

[0016] Overview of Wireless Power Systems FIG. 1 is a block diagram of an exemplary wireless power system 100. The system 100 includes a wireless power transmitter 102 and a wireless power receiver 104. In the transmitter 104, a power source (e.g., AC mains, a battery, etc.) provides power to an inverter 108. Additional components may include a power factor correction (PFC) circuit 106 before the inverter stage 108. The inverter 108 drives a transmitter resonator coil and a capacitive component 112 ("resonator") through an impedance matching network 110 (comprising fixed and / or adjustable network elements). The transmitter resonator 112 generates an oscillating magnetic field that induces a voltage and / or current in a receiver resonator 114. The received energy is provided to a rectifier 118 through an impedance matching network 116 (comprising fixed and / or adjustable network elements). Finally, the rectified power is provided to a load 120 (e.g., one or more batteries of an electric or hybrid vehicle). In some embodiments, the battery voltage level may affect various parameters (e.g., impedance) of the wireless power system 100. Thus, the battery voltage level may be received, determined, or measured to be provided as an input to other portions of the wireless power system 100. For example, typical battery voltage ranges for electric vehicles include 200-280V, 200-350V, 200-420V, etc.

[0017] In some embodiments, one or more components of the transmitter 102 may be coupled to a controller 122, which may include a communications module (e.g., Wi-Fi, radio, Bluetooth, in-band signaling mechanisms, etc.) configured to communicate with a communications module of the receiver 104. In some embodiments, one or more components of the transmitter 102 may be coupled to one or more sensors 124 (e.g., current sensors, voltage sensors, power sensors, temperature sensors, fault sensors, etc.). The controller 122 and the sensors 124 may be operatively coupled to control portions of the transmitter 102 based on feedback signals from the sensors 124 and / or 128.

[0018] In some embodiments, one or more components of the receiver 104 may be coupled to a controller 126, which may include a communications module (e.g., Wi-Fi, radio, Bluetooth, in-band signaling mechanisms, etc.) configured to communicate with a communications module of the transmitter 102. In some embodiments, one or more components of the transmitter 104 may be coupled to one or more sensors 128 (e.g., current sensors, voltage sensors, power sensors, temperature sensors, fault sensors, etc.). The controller 126 and the sensors 128 may be operatively coupled to control portions of the transmitter 102 based on feedback signals from the sensors 128 and / or the sensors 124.

[0019] Examples of wireless power systems can be found in U.S. Patent Application Publication No. 2010 / 0141042, published on June 10, 2010, and entitled "Wireless energy transfer systems," and U.S. Patent Application Publication No. 2012 / 0112535, published on May 10, 2012, and entitled "Wireless energy transfer for vehicles," both of which are incorporated by reference in their entireties herein.

[0020] The exemplary systems and methods disclosed herein may be described with respect to vehicle applications, but may also be applied to any system or device powered by electricity, such as robots, industrial machines, electrical appliances, household appliances, etc. The high-power wireless power transmitter may be configured to transmit wireless power in applications such as powering and / or charging batteries of vehicles, industrial machines, robots, or electronic devices that rely on high power. For illustrative purposes, the following disclosure focuses on vehicular wireless power transmission. However, it will be understood that any one or more of the embodiments described herein may be applied to other applications in which wireless power may be utilized.

[0021] As used herein, a "capacitor," or a symbol thereof, may refer to one or more electrical components having a capacitance (e.g., in Farads) and / or a capacitive reactance (e.g., in Ohms). For example, a capacitor may refer to one or more capacitors (e.g., in a "bank" of capacitors), which may be tens or hundreds of discrete capacitors. Two or more capacitors may be coupled in series or parallel to achieve a desired capacitance and / or a desired capacitive reactance. It should be noted that capacitive reactance may be represented herein as a negative value. However, one skilled in the art will recognize that in some conventions, capacitive reactance may also be represented as a positive value.

[0022] As used herein, "inductor," or its symbol, may refer to one or more electrical components having an inductance (e.g., in Henry) and / or an inductive reactance (e.g., in Ohms). For example, an inductor may refer to one or more separate inductors or coils. Two or more inductors may be coupled in series or parallel to achieve a desired inductance and / or a desired inductive reactance. Note that inductive reactance may be represented herein as a positive value.

[0023] While this disclosure, including the drawings, may provide example values ​​for various electrical components, it will be understood that the component values ​​may be customized for a particular application. For example, the values ​​of the various electronic components may depend on whether the wireless power transmitter is used to transmit power to charge a vehicle battery (on the order of several thousand watts) or a cell phone battery (typically less than 5 watts).

[0024] Active rectification in radio receivers In some embodiments, active rectification can enable greater control over power transfer to the output of the receiver 104 and / or the load 120. In some embodiments, active rectification can enable more efficient power transfer to the output of the receiver 104 and / or the load 120. In some embodiments, by employing active rectification in a wireless power receiver, tunable impedance matching components in the receiver 104 and / or the transmitter 102 can be eliminated. This has the advantage of reducing size, weight, and / or cost associated with wireless power systems.

[0025] 2A is a schematic diagram of an example wireless power system 200 utilizing active rectification. The example system 200 includes a wireless power transmitter 202. The example transmitter 202 includes an inverter 206 (e.g., a half-bridge inverter, a full-bridge inverter, etc.) coupled to a filter circuit 207 (e.g., which may include one or more inductive components L3sA, L3sB, one or more capacitive components, etc.). The inverter 206 may include two or more switches (e.g., transistors Q1, Q2, Q3, and Q4). The switches Q1, Q2, Q3, Q4 may be controlled via respective control signals PWM1, PWM2, PWM3, PWM4. The filter 207 may further be coupled to a transmit resonator and / or matching circuit 208 (including capacitors C2s, C1sA, C1sB, and inductor L1s), as described above.

[0026] In the exemplary system 200, the inductor L1s of the circuit 208 may be inductively coupled to the inductor L1d of the receiver resonator and / or the matching circuit 210 (including the capacitors C1dA, C1dB, C2d, and the inductor L1d) to wirelessly transfer power from the transmitter 202 to the receiver 204a. Note that the transmitter coil L1s generates an oscillating magnetic field that can induce an oscillating current in the receiver coil L1d. This current may have a frequency of, for example, 85 kHz. In many cases, the current I3d may include harmonics due to the inverter 206. In some embodiments, the characteristics of the current I3d (e.g., phase, amplitude, shape, harmonic content, etc.) may be further influenced (e.g., shaped, distorted, etc.) by one or more components of the receiver 204a. For example, the circuits 210 and 212 may include inductive and / or capacitive components that can change the phase or shape of the current I3d. In some cases, as described further below, distortion of current I3d can create challenges in the operation of the rectifier switches.

[0027] The exemplary receiver 204a may include a filter circuit 212 (e.g., including one or more inductive components L3dA, L3dB, one or more capacitive components, etc.) coupled to the receive resonator and / or matching circuit 210. The filter circuit 212 may be configured to modify a characteristic of the current I3d (e.g., to reduce distortion).

[0028] The filter circuit 212 may be coupled to a rectifier 214a (e.g., a half-bridge inverter, a full-bridge inverter, etc.) that may include two or more switches (e.g., transistors Q5, Q6, Q7, and Q8). The exemplary rectifier 214a may be directly or indirectly coupled to a load 216 (e.g., a battery). In some embodiments, a current sensor 218 may determine (e.g., measure, sense, etc.) a characteristic of the current I3d. The current sensor 218 may be coupled at an output of the filter 212 and / or at an input of the rectifier 214. For example, the current sensor 218 may determine a phase of the current I3d at the input of the rectifier 214. The sensor signal may be provided to a processor and / or controller (e.g., controller 126) for processing. In some embodiments, the processor and / or controller may generate a control signal (e.g., a PWM signal) to control one or more switches of the rectifier 214 based on the current sensor 218 signal. The processor and / or controller may provide control signals (e.g., PWM5, PWM6, PWM7, PWM8) to one or more switches (e.g., Q5, Q6, Q7, Q8, respectively) of the rectifier 214. In some embodiments, the current sensor 218 may include a zero-crossing detector configured to detect zero crossings by the current I3d, as described in further detail below. The detector signal may be provided to the controller to determine a control signal for the switch.

[0029] In some embodiments, the control signal may operate the rectifier switches in various modes. The modes may include hard switching and / or soft switching (e.g., zero voltage switching). In some embodiments, the rectifier switches may operate in one mode during a first period of time and in another mode during a second period of time. In some cases, the switches may alternate or transition between the two modes during a given period of time.

[0030] Reference is made herein to the following non-limiting exemplary specifications for the wireless power system 200: - The transmitter coil L1s may be disposed on a single or multiple layers of ferrite. ● The system 200 is configured to supply approximately 11.3 kW of power to the load 216. ● The receiver coil L1d may have 15 turns or less, 20 turns or less, 25 turns or less, etc. (eg, about 16 turns). ●Matching can be configured for the voltage range Vbus=300-900V (e.g., 640-840V).

[0031] 2B illustrates an alternative embodiment of a wireless power receiver 204b that includes an active rectifier 214b. The receiver 204b includes the same or similar components as described herein with respect to the receiver 204a. However, the rectifier 214b is a full-bridge active rectifier with diodes D5, D6 in the high-side position and switches Q7, Q8 in the low-side position.

[0032] 2C illustrates another alternative embodiment of a wireless power receiver 204c including an active rectifier 214c. The receiver 204c includes the same or similar components as described herein with respect to the receiver 204a. However, the rectifier 214c is a full-bridge active rectifier having (i) diodes D6, D8 coupled between the input node 220 and the output of the rectifier 214c, and (ii) switches Q5, Q7 coupled between the input node 222 and the output of the rectifier 214c. In an alternative embodiment, the active rectifier may be a full-bridge active rectifier having (i) switches Q6, Q8 (replacing the diodes D6, D8 of FIG. 2C) coupled between the input node 220 and the output of the rectifier, and (ii) diodes D5, D7 (replacing the switches Q5, Q7 illustrated in FIG. 2C) coupled between the input node 222 and the output of the rectifier. It should be noted that one or more of the following methods can be used to control the switches of rectifiers 214a, 214b, or 214c.

[0033] First Exemplary Method—Resistive Input Impedance 3A is a schematic diagram of an example wireless power system 300 utilizing active rectification. It should be noted that system 300 may include components of system 200 discussed above (e.g., rectifiers 214a, 214b, or 214c). In some embodiments, system 300 may include a receiver 303 having one or more capacitors C3dA coupled between an inductor L3dA of rectifier 214a and a first input 301a, and one or more capacitors C3dB coupled between an inductor L3dB of rectifier 214a and a second input 301b.

[0034] FIG. 3B illustrates an example workflow 302 corresponding to an example method for determining control signals (e.g., PWM5, PWM6, PWM7, PWM8, respectively) for rectifier switches (e.g., Q5, Q6, Q7, Q8) based on an input current I3d. FIG. 3C is a set of plots illustrating various signals in the generation of the control signals as a function of time. FIG. 3D illustrates an example method 304 for determining control signals for active rectification in a rectifier that presents a resistive impedance to one or more portions of a wireless power system (e.g., transmitter 202, components between Vbus and arrow 305, etc.). For clarity and brevity, FIGS. 3A-3D are discussed together herein.

[0035] With reference to FIG. 3B, the current I3d may be input to a zero-crossing detector 306 (e.g., of the control system 322). An example current I3d is provided in FIG. 3C(i). In step 308 of the example active rectification method 304, the detector 306 is configured to detect zero crossings of the input current I3d. With reference to FIG. 3C(ii), the detector 306 may output a zero-crossing detection signal Vzcd indicative of zero crossings of the current signal I3d. For example, the current I3d has a rising zero crossing at time t0 and a falling zero crossing at time t5. As shown in FIG. 3C(iii) and FIG. 3C(v), the zero-crossing information may be used to synchronize the switching patterns of the switches Q5, Q6, Q7, and / or Q8 to the I3d current zero crossings. In particular, the rising edge 310a (at time t0) and the falling edge 310b (at time t5) of the signal Vzcd may be used to synchronize the switching patterns of the switching signals PWM pdt5 and PWM pdt7 and the switching signal PWM (shown in FIG. 3C(v)). pdt6 and PWM pdt8 You can coordinate the timing with.

[0036] The signal having the zero-crossing information (e.g., the voltage Vzcd) may be provided to a delay block 312 (e.g., of the control system 322). In step 314, the delay block 312 determines a first delay time T based on a system parameter (e.g., β, which is further described below). del1 and the second delay time T del2 The example delay block 312 may be configured to provide one or more time delays according to the following relationship: Time Delay 1:T del1 =(270-β) / 360×T period Time Delay 2:T del2 =(90+β) / 360×T period -T dead In the formula, 0≦β≦90°, and T periodis a single time period of the input signal I3d, and time T dead is a fixed amount (e.g., on the order of a few hundred nanoseconds) based on the specifications of the transistors and / or gate drivers used. dead can be made large enough so that no shoot-through condition occurs during the phase delay and one transistor of a pair of transistors conducts at a given time. For example, switch Q5 should not be turned on at the same time as its counterpart, switch Q7. As described below, these time delays can be used to delay control signals (e.g., PWM pdt5 , PWM pdt6 , PWM pdt7 , PWM pdt8 ) may be generated. The delay control signal may be provided to a dead-time compensation block 306.

[0037] The parameter β may be determined by the controller depending on the desired system optimization. In some embodiments, the controller may be configured to create an equivalent impedance of the rectifier 214 and thus select β to achieve that impedance. In some embodiments, the controller may be configured to maintain the impedance of the rectifier regardless of changes in the battery voltage (at the load 216) and thus select β to achieve maintenance. In some embodiments, the controller may be configured to maintain the power provided to the load 216 within a certain range and thus select β to achieve power maintenance. In some embodiments, β may be selected to maintain a desired coil current (e.g., of L1d) at the receiver side.

[0038] In some embodiments, T del1 is the period (T period ) 0.5~period (T period In some embodiments, T del2 is the period (T period ) 0.25~period (T period ) can be 0.5. The delay time T del1may be used for the control signals of the switches Q5 and Q7. del2 may be used as the control signal for the switches Q6 and Q8. Note that the switches Q5 and Q7 form the soft switching leg, and the switches Q6 and Q8 form the hard switching leg. In the example shown in FIG. 3C, the delay time T del1 corresponds to the difference between times t0 and t6, and the delay time T del2 corresponds to the difference between t0 and t3.

[0039] In step 316, the control system 322 (e.g., a controller 318 and / or a processor 320 coupled to the switch) determines a first delay time T del1 based on the first "pre-dead time" control signal PWM pdt5 and the second "before dead time" control signal PWM pdt7 For example, a rising edge 310a and a falling edge 310b of the signal Vzcd can be used to generate the signal PWM pdt5 and PWM pdt7 The edges 324a and 324b are generated.

[0040] In step 326, the control system 322 determines a second delay time T del2 and a third "before-dead-time" control signal PWM for the third rectifier switch Q6 and the fourth rectifier switch Q8, respectively, based on pdt6 and the fourth "before dead time" control signal PWM pdt8 For example, a rising edge 310a and a falling edge 310b of the signal Vzcd can be used to generate the signal PWM pdt6 and PWM pdt8 The edges 328a and 328b are generated.

[0041] In step 328, the dead time insertion block 330 respectively receives a first pre-dead time control signal and a second pre-dead time control signal, a PWMpdt5 and PWM pdt7 There is a dead time T dead It is possible to insert a PWM signal. pdt5 and PWM pdt7 In FIG. 3C(iv), arrows 332a and 332b indicate the time lag between the respective edges of signals PWM5, PWM7 (e.g., T dead = t7-t6 and T dead = t12-t11) dead Shows.

[0042] In step 334, the dead time insertion block 330 respectively generates a third pre-dead time control signal and a fourth pre-dead time control signal, a PWM pdt6 and PWM pdt8 There is a dead time T dead It is possible to insert a PWM signal. pdt6 and PWM pdt8 In FIG. 3C(vi), arrows 336a and 336b indicate the time lag between the edges of the signals PWM6 and PWM8 (e.g., T dead = t4-t3 and T dead = t9-t8) dead Shows.

[0043] At step 338, the control system 322 can provide control signals to the respective rectifier switches. In an example of a full-bridge rectifier having four switches (such as rectifier 214a), a control signal PWM5 is generated for switch Q5, a control signal PWM6 is generated for switch Q6, a control signal PWM7 is generated for switch Q7, and a control signal PWM8 is generated for switch Q8. In another example for a rectifier having two high-side diodes and two low-side switches Q7 and Q8 (such as rectifier 214b), only the control signals PWM7 and PWM8 are provided to the respective switches Q7 and Q8. In yet another example for rectifier 214c, the control signals PWM5 and PWM7 are provided to the respective switches Q5 and Q8.

[0044] For an example receiver 303 of system 300 having the specifications presented above and utilizing workflow 302, the value of the filter inductor L3dA in system 300 may be approximately 35 μH. A series compensation capacitor can be used to maintain the same impedance at 85 kHz as a 7 uH inductor.

[0045] Second Exemplary Method—Resistive Input Impedance FIG. 4A illustrates a workflow 400 of an example method for generating a control signal for a rectifier switch based on an input current I3d. FIG. 4B is a set of plots illustrating various signals in the generation of the control signal as a function of time. FIG. 4C illustrates an example method 402 for generating a control signal for a rectifier that presents a resistive impedance to one or more portions of a wireless power system (e.g., the transmitter 202, the components between Vbus and the arrow 305, etc.). For clarity and brevity, FIGS. 4A-4C are considered together herein.

[0046] 4A, the current I3d may be provided to a zero-crossing detector 406 (e.g., of the processor 320). An exemplary current I3d is provided in FIG. 4B(i). At step 404 of the exemplary method 402, the zero-crossing detector 406 may detect a rising zero crossing at time t0 of the rising input current signal I3d and a falling zero crossing at time t5 of the falling input current signal I3d. The zero-crossing detector 406 may output a voltage signal Vzcd having zero-crossing information of the current signal I3d.

[0047] In step 408, a phase delay lock (PLL) block 410 can generate a PLL signal based on the rising and falling zero crossings of the current I3d. The block 410 outputs a PLL signal "SYNC" as shown in FIG. 4B(iii), which is a signal "synchronized" to the zero crossing signal Vzcd such that the signal SYNC is in phase with the signal Vzcd. In some embodiments, the SYNC signal may be a copy of the voltage signal Vzcd. In some embodiments, the SYNC signal may have the same phase and / or frequency of the signal Vzcd with a different magnitude than the voltage signal Vzcd. For example, the rising edge of Vzcd corresponds to the rising edge of SYNC at time t0 (indicated by arrow 412a), and the falling edge of Vzcd corresponds to the falling edge of SYNC at time t5 (indicated by arrow 412b).

[0048] In step 413, a delay block 414 determines a first delay time T based on system parameters (e.g., β, which is further described below). del1 and the second delay time T del2 The delay block 414 may generate one or more time delays according to the following relationship: Time Delay 1:T del1 =(270-β) / 360×T period Time Delay 2:T del2 =(90+β) / 360×T period -T dead In the formula, 0≦β≦90°, and T period is a single time period of the input signal I3d, and time T dead is a fixed quantity based on the transistor and / or gate driver specifications. dead can be made large enough so that no shoot-through condition occurs during the phase delay and one transistor of a pair of transistors conducts at a given time. For example, switch Q5 is not turned on at the same time as its paired switch Q7. The delay signal can be provided to a dead-time compensation block 428.

[0049] The parameter β may be determined by the controller depending on the desired system optimization. In some embodiments, the controller may be configured to generate an equivalent impedance of the rectifier 214 and thus select β to achieve that impedance. In some embodiments, the controller may be configured to maintain the impedance of the rectifier regardless of changes in the battery voltage (at the load 216) and thus select β to achieve maintenance. In some embodiments, the controller may be configured to maintain the power provided to the load 216 within a certain range and thus select β to achieve maintenance of power. In the example provided in FIG. 4B, the parameter β is selected to be 47 degrees.

[0050] In some embodiments, T del1 is the period (T period ) 0.5~period (T period In some embodiments, T del2 is the period (T period ) 0.25~period (T period ) can be 0.5. The delay time T del1 may be used for the control signals of the switches Q5 and Q7. del2may be used as the control signal for the switches Q6 and Q8. Note that the switches Q5 and Q7 form the soft switching leg, and the switches Q6 and Q8 form the hard switching leg. In the example shown in FIG. 4B, the delay time T del1 corresponds to the difference between times t0 and t6, and the delay time T del2 corresponds to the difference between t0 and t3.

[0051] In step 416, the delay block 414 receives the PLL signal SYNC and the first delay time T del1 Based on the first and second "before dead time" control signals, PWM pdt5 and PWM pdt7 For example, the rising edge 420a and the falling edge 420b of the signal SYNC can be used to generate the signal PWM pdt5 and PWM pdt7 The edges 420a and 420b are generated.

[0052] In step 422, the delay block 414 receives the PLL signal SYNC and a second delay time T del2 based on a third “before dead time” control signal and a fourth “before dead time” control signal for the third rectifier switch Q6 and the fourth rectifier switch Q8, respectively, pdt6 and PWM pdt8 For example, the rising edge 412a and the falling edge 412b of the signal SYNC can be used to generate the signal PWM pdt6 and PWM pdt8 The edges 424a and 424b are generated.

[0053] In step 426, a dead-time compensation block 428 respectively generates a first "before-dead-time" control signal and a second "before-dead-time" control signal, a PWM pdt5 and PWM pdt7 There is a dead time T dead4B(v) illustrates dead time insertion. By inserting dead time between time t6 and time t7, the control system 322 generates the control signals PWM5, PWM7 for the respective rectifier switches Q5, Q7. In FIG. 4B(v), arrows 430a, 430b indicate the time lag (e.g., T dead = t7-t6 and T dead = t11-t12) dead Shows.

[0054] In step 432, block 428 generates a third "before dead time" control signal and a fourth "before dead time" control signal, respectively, PWM pdt6 and PWM pdt8 There is a dead time T dead FIG. 4B(vii) illustrates dead time insertion. By inserting dead time between times t3 and t4, the control system generates control signals PWM6, PWM8 for the respective rectifier switches Q6, Q8. In FIG. 4B(vii), arrows 434a, 434b indicate the time lag (e.g., T) between respective edges of signals PWM6, PWM8. dead = t4-t3 and T dead = t9-t8) dead Shows.

[0055] At step 434, the control system 322 can provide control signals (e.g., PWM5, PWM6, PWM7, and PWM8) to the respective rectifier switches (e.g., Q5, Q6, Q7, and Q8, respectively). In an example of a full-bridge rectifier (e.g., rectifier 214a) having four switches, a control signal PWM5 is generated for switch Q5, a control signal PWM6 is generated for switch Q6, a control signal PWM7 is generated for switch Q7, and a control signal PWM8 is generated for switch Q8. In another example for a rectifier (e.g., rectifier 214b) having two high-side diodes and two low-side switches Q7 and Q8, only the control signals PWM7 and PWM8 are provided to the respective switches Q7 and Q8. In yet another example for rectifier 214c, the control signals PWM5 and PWM7 are provided to the respective switches Q5 and Q8.

[0056] The value of the filter inductors L3sA, L3sB in the method 402 for the example receiver 204 of the system 200 having the specifications presented above may be about 14 μH. Note that the value of the filter inductors L3sA, L3sB in the method 402 is about one-fifth the value of the filter inductors L3sA, L3sB in the method 304. This may result in a reduced footprint (e.g., size, volume, etc.) and / or cost of a system employing the method 402.

[0057] Third Exemplary Method—Capacitive Input Impedance FIG. 5A illustrates a workflow 500 corresponding to an example method for generating a control signal for a rectifier switch based on an input current I3d. FIG. 5B is a set of plots illustrating various signals in the generation of the control signal as a function of time. FIG. 5C illustrates an example active rectification method 502 in a rectifier that presents a capacitive impedance to one or more portions of a wireless power system (e.g., the transmitter 202, components between Vbus and the arrow 305, etc.). For clarity and brevity, FIGS. 5A-5C are discussed together herein.

[0058] At step 504, a sensor 506 may receive an input current I3d. In some embodiments, the sensor 506 may include a filter (e.g., a bandpass filter, a lowpass filter, a highpass filter, etc.). In a preferred embodiment, the exemplary sensor 506 includes a bandpass filter characterized by the following transfer function:

number

[0059] In step 510, the zero crossing detector 508 can detect the rising zero crossing of the filtered current signal I3dmf and the falling zero crossing of the filtered current signal I3dmf. The detector 508 can generate an output signal ZCD (e.g., voltage Vzcd and / or current Izcd) having zero crossing information. For example, as shown in FIG. 5B(iii), edge 512a of the signal ZCD corresponds to the rising zero crossing (at time t0) of the signal I3dmf, and edge 512b of the signal ZCD corresponds to the falling zero crossing (at time t4) of the signal I3dmf.

[0060] In step 514, a delay block 516 determines a delay time T based on system parameters (e.g., β, which is further described below). del1 The delay block 516 may generate one or more time delays according to the following relationship: Time Delay: T del1 =(270-β) / 360×T period In the formula, 0≦β≦90°, and T period is a single time period of the input signal ZCD, and time T deadis a fixed quantity based on the transistor and / or gate driver specifications. dead can be made large enough so that no shoot-through condition occurs during the phase delay and one transistor of a pair will conduct at a given time. For example, switch Q5 will not be on at the same time as its paired switch Q7. The delayed signal PWM pdt5 , PWM pdt7 may be provided to the dead time compensation block 518.

[0061] The parameter β may be determined by the controller depending on the desired system optimization. In some embodiments, the controller may be configured to generate an equivalent impedance of the rectifier 214 and thus select β to achieve that impedance. In some embodiments, the controller may be configured to select β to maintain the impedance of the rectifier constant regardless of changes in the battery voltage (at the load 216) and thus achieve maintenance. In some embodiments, the controller may be configured to maintain the power provided to the load 216 within a certain range and thus select β to achieve power maintenance. In the example provided in FIG. 5B, the parameter β was selected to be 75 degrees.

[0062] In step 520, the delay block 516 generates a delay time T del1 based on first and second "before-dead-time" control signals PWM for the first and second rectifier switches, Q5 and Q7, respectively. pdt5 and PWM pdt7 In the example shown in FIG. 5B, the delay time T del1 corresponds to the difference between times t0 and t5. For example, rising edge 512a and falling edge 512b of signal ZCD are used to pdt5 and PWM pdt7 The edges 522a and 522b are generated.

[0063] In step 524, a dead time insertion block 526 inserts a dead time T between the first “before dead time” signal control signal and the second “before dead time” control signal. dead By inserting a dead time between times t5 and t6, the control system 322 generates control signals PWM pdt5 and PWM pdt7 In particular, in plot FIG. 5B(v), arrows 528a, 528b indicate the dead time T between edges of signals PWM5, PWM7. dead The commutation of the diode half bridge (e.g., diodes D6 and D8) is t7-t3=T period Note that this occurs between times t3 and t7, such that t = 1 / 2.

[0064] At step 530, the control system 322 may provide control signals PWM5, PWM7 to respective rectifier switches Q5, Q7 (eg, of rectifier 214c).

[0065] One advantage is that the example method 502 may enable the use of smaller inductors in the filter inductors L3sA, L3sB, thereby reducing the physical volume of the receiver 204. The example method 502 may also achieve higher efficiency compared to methods that include active control of the four switches (e.g., Q5, Q6, Q7, and Q8) of the rectifier 214.

[0066] Fourth Exemplary Method—Phase Shift Control Figure 6A shows the input current I3d and the input voltage V AC6A-6D show a workflow 600 of an example method for generating control signals for rectifier switches by controlling the relative phase shift between the rectifier switch and the rectifier output (Vacd). FIGS. 6B-6C are a set of plots illustrating generation of control signals as a function of time according to the workflow 600. FIG. 6D shows a method 602 for generating control signals according to the workflow 600. Note that the control scheme of the method 602 may be implemented in mixed-signal or digital domains. For clarity and brevity, FIGS. 6A-6D are considered together herein.

[0067] With reference to FIG. 6A, the current I3d may be input to a zero-crossing detector 604 (e.g., of the control system 322). An example current I3d is provided in FIG. 6B(v). In step 606, the detector 604 is configured to detect zero crossings of the input current I3d. With reference to FIG. 6B(i), the detector 604 may output a zero-crossing detection signal Vzcd indicative of the zero crossings of the current signal I3d. As described herein for other methods, the zero-crossing information may be used to synchronize the switching patterns of the switches Q5, Q6, Q7, and / or Q8 to the zero crossings of the current.

[0068] In step 608, a phase delay lock (PLL) block 610 can generate a PLL signal based on the rising and falling zero crossings of the current I3d. The block 610 outputs a PLL signal "SYNC" as shown in FIG. 6B(ii), which is a signal "synchronized" to the zero crossing signal Vzcd such that the signal SYNC is in phase with the signal Vzcd. In some embodiments, the SYNC signal can have a frequency at least twice the frequency of the voltage signal Vzcd. In some embodiments, the SYNC signal can have a different magnitude than the voltage signal Vzcd. For example, a rising edge of Vzcd corresponds to a falling edge of SYNC (indicated by arrow 612a), and a falling edge of Vzcd corresponds to a rising edge of SYNC (indicated by arrow 612b) such that one period of the signal Vzcd corresponds to two periods of the signal SYNC.

[0069] In step 614, a ramp generation block 616 (e.g., of the control system 322) can generate at least one ramp signal Vramp based on the output PLL signal. The ramp signal Vramp can be used to generate a PWM signal with the help of Vdc1 and Vdc2 defined by the following relationship:

number

[0070] In step 618, a PWM generator 620 (e.g., control 622) generates a pre-dead-time PWM signal PWM for switches Q5, Q6, Q7, and Q8 based on signals Vdc1 and Vdc2. pdt5 , PWM pdt6, PWM pdt7 , PWM pdt8 In some embodiments, a control system (e.g., a modulator of system 322) can modulate signals Vdc1 and Vdc2 to form a control signal (e.g., a dead-time PWM signal).

[0071] In frequency division block 622, the frequency of the pre-dead-time PWM signal is divided. In some embodiments, the frequency is divided by a factor of 2. In some embodiments, the frequency is divided by a factor greater than 2 (e.g., 2.5, 3, 4, etc.).

[0072] In step 624, a dead time compensation block 626 calculates the dead time T dead The first dead time before control signal PWM pdt5 and the second pre-dead-time control signal PWM pdt7 By inserting dead time, the control system 322 generates the control signals PWM5, PWM7 for the respective rectifier switches Q5, Q7.

[0073] In step 628, block 626 determines the dead time T dead , the third dead time before control signal PWM pdt6 and the fourth "before dead time" control signal PWM pdt8 By inserting a dead time, the control system generates control signals PWM6, PWM8 for the respective rectifier switches Q6, Q8.

[0074] At step 630, the control system 322 can provide control signals (e.g., PWM5, PWM6, PWM7, and PWM8) to the respective rectifier switches (e.g., Q5, Q6, Q7, and Q8, respectively). In an example of a full-bridge rectifier (e.g., rectifier 214a) having four switches, a control signal PWM5 is generated for switch Q5, a control signal PWM6 is generated for switch Q6, a control signal PWM7 is generated for switch Q7, and a control signal PWM8 is generated for switch Q8. In another example for a rectifier (e.g., rectifier 214b) having two high-side diodes and two low-side switches Q7 and Q8, only the control signals PWM7 and PWM8 are provided to the respective switches Q7 and Q8. In yet another example for rectifier 214c, the control signals PWM5 and PWM7 are provided to the respective switches Q5 and Q8.

[0075] Application to bidirectional wireless power transmission In various embodiments, the active rectification systems and methods described herein may be employed in a bidirectional wireless power system. For example, the wireless power system may be configured such that wireless power is transmitted from a transmitter to a receiver (also referred to as "unidirectional"). In some cases, the wireless power system may be configured such that wireless power is transmitted from a first device to a second device (e.g., from a transmitter to a receiver) and / or from a second device to a first device (e.g., from a receiver to a transmitter). Examples of bidirectional wireless power systems and methods can be found in U.S. Patent Application Publication No. 2019 / 0006836, published on January 3, 2019, entitled "Protection and control of wireless power systems," and U.S. Patent Application Publication No. 2020 / 0094696, published on March 26, 2020, entitled "Wireless power transmission in electric vehicles."

[0076] FIG. 7 shows a schematic diagram of an exemplary bidirectional wireless power system 700. The schematic diagram illustrates both a transmitter (Tx) side wireless power device 700a and a receiver (Rx) side wireless power device 700b. As described above, the Tx side wireless power device 700a generally operates as a wireless power transmitter in the case of a similar unidirectional wireless power system (e.g., system 200 or 300). The Tx side device 700a may also be referred to as a grounding assembly (GA) or a GA side device when used in the context of a wireless power device coupled to an electric vehicle or other mobile vehicle. However, as discussed below, the Tx side in a bidirectional system generally refers to a wireless power device that is coupled or configured to be coupled to a static power source or load, such as a power grid, an AC generator, etc. Furthermore, the Tx side system generally can handle higher power, voltage, or current transients than the Rx side wireless power device 700b. Meanwhile, the Rx-side wireless power device 700b generally operates as a wireless power receiver in a similar unidirectional wireless power transmission system (e.g., system 200 or 300). However, as discussed below, in a bidirectional system, the Rx-side generally refers to a wireless power device that is coupled or configured to be coupled to a mobile (or generally more limited) power source or load, such as a battery or battery-powered device (e.g., a computing device or electric vehicle). The Rx-side wireless power device 700b may also be referred to as a vehicle assembly (VA) or VA-side device when used in the context of a wireless power device coupled to an electric vehicle or other mobile vehicle.

[0077] In the exemplary bidirectional system 700, both the Tx side device 700a and the Rx side device 700b include an inverter rectifier 702. The inverter rectifier 702 may include a bridge configuration of switching elements and / or diodes. For example, the inverter rectifier 702 may include active switching elements, such as MOSFETs, that allow the inverter rectifier 702 to operate as either an inverter or a rectifier in a bidirectional system. As discussed in more detail below, the operating mode (also referred to herein as "operation personality") of the inverter rectifier 702 may be controlled based on a pattern of PWM control signals provided to the switching elements. In some embodiments, the inverter rectifier 702 may operate according to one or more active rectification methods (e.g., methods 304, 402, 502, and / or 602) described herein.

[0078] The system 700 can supply power to a load, such as a vehicle battery, in a first direction (e.g., normal power flow direction from transmitter 700a to receiver 700b) from power input to the transmitter 700a. Alternatively, the system 700 can supply power in a second direction (e.g., reverse power flow direction), such as supplying power from a battery in an electric vehicle coupled to the Rx side device 700b to a power grid coupled to the Tx side device 700a. As another example, the bidirectional system 700 can be used to supply power to a house during a power outage from a battery in an electric vehicle parked in a garage.

[0079] In cases where single components including resistors, inductors, and capacitors are shown, banks of components including series and / or parallel may be utilized. In cases where adjustable components are shown, fixed components may be included in series and / or parallel with the adjustable components. In some implementations, the controllers 122a and 122b may be combined within a single controller 720. Similarly, in some implementations, the controllers 126a and 126b may be combined within a single controller 740.

[0080] In some implementations, the controllers 720 and 740 include a bidirectional manager. The bidirectional manager coordinates the configuration of the wireless power device (e.g., either 700a or 700b) of different hardware and software components depending on the direction of power flow indicated by the operation personality assigned to the device. For example, an operation personality of INV indicates that the inverter rectifier is operating as an inverter and thus the wireless power device 700a / 700b is operating as a transmitter. Similarly, for example, an operation personality of REC indicates that the inverter rectifier is operating as a rectifier and thus the wireless power device 700a / 700b is operating as a receiver. The bidirectional manager also coordinates the transition from one direction of power flow to the opposite direction of power flow. For example, the bidirectional manager of the Rx side device 700b can communicate with the bidirectional manager of the Rx side device 700a via a wireless communication link 750 (e.g., a Wi-Fi link) to coordinate the power reversal. The interactive manager may be implemented as a separate controller within each device 700a / 700b or in software.

[0081] More specifically, various hardware and software components of the system may have different operating settings, modes and / or ranges depending on the direction of power flow, and by extension, the operating personality of the wireless power device 700a / 700b. The various operating settings, modes and / or ranges may be stored in memory or hardware. Each component of the system (e.g., inverter rectifier 702, tunable matching network (TMN) 703, and other components), including various controllers, filters, communication systems, and / or protection systems, may assume a different "operating personality" depending on the direction of power flow.

[0082] The bidirectional manager of the wireless power device can assign an appropriate personality at system startup and / or during power flow transitions based on the expected direction of power flow as a whole through the wireless power system 700. For example, upon receiving a command to switch from one operating mode of the system to another (e.g., by an operator interface and / or by a user interface connected to any or all of the controllers on one or both sides of the system or to a controller outside the system such as a network, grid, or mobile device), the bidirectional manager can assign respective operating personalities to the various component controllers (e.g., 122a, 122b, 126a, and 126b). Each controller can use the assigned operating personality to identify and load the appropriate operating process or software code for controlling the associated components of the wireless power transmitting device 700a / 700b. For example, if the inverter rectifier controller is assigned an inverter operating personality (e.g., INV), the controller loads software code for generating a PWM control signal pattern to operate the inverter rectifier switching elements to generate an AC output signal from a DC input signal. On the other hand, if the inverter rectifier controller is assigned a rectifier operating personality (e.g., REC), the controller loads software code to generate PWM control signal patterns to operate the inverter rectifier switching elements to rectify the AC input signal into a DC output signal.

[0083] Additionally, the bidirectional manager can provide power demand, direction of power flow, select appropriate software code blocks, and assign personalities to sub-controllers or other controllers. The bidirectional manager can identify recoverable or non-recoverable errors depending on the side of the system the controller is located on and the operational personality for which the controller is responsible for the components of the system. The operational personality can be assigned based on the expected direction of power flow, e.g., vehicle-to-grid (V2G) power flow, or grid-to-vehicle (G2V) power flow. Additionally, the bidirectional manager can determine the time and / or mode for recovery of these errors and / or clear the errors when they are recovered, so that no user intervention is required. The bidirectional manager can communicate with the user, the controller on the other side of the system (e.g., the bidirectional manager on the other side of the system).

[0084] The bidirectional manager can receive notification of an error from a component of the wireless power system, and an error message can be assigned to other components of the wireless power system either directly by the bidirectional manager or following a callback request from the component.

[0085] The bidirectional manager can receive communications from components of the wireless power system (e.g., via Wi-Fi from components from the other side of the system). The bidirectional manager can fulfill callback requests from components for messages related to the components or assign messages to the associated components. The bidirectional manager can control, including dynamic control, the authority of the components of the wireless power system to send and receive error and communication messages. The bidirectional manager can be responsible for controlling the components of the wireless power system during transition phases, including handling any error conduction resulting from changes in power transfer direction (both V2G and G2V transitions). For example, the bidirectional manager can oversee the disconnection of power supplies, ensure that power supplies are fully or partially turned off, and sequence the components of the system to turn them on (while assigning personalities to the components).

[0086] As an example, a bidirectional manager on a transmitter controller may receive a command to power on from idle, and the bidirectional manager may assign G2V personalities to the various controllers and hardware in the system. Upon receiving a communication to change the power transmission direction, the bidirectional manager communicates between the transmitter and receiver to change the power transmission direction. The bidirectional manager may be responsible for handling any errors resulting from the change in power transmission direction, including during power down of the first direction and power up of the second direction. Once the errors are cleared, the bidirectional manager may assign personalities to the controllers, for example, by selecting a subset of instructions from a non-transitory computer readable medium or by having the controller select a subset of instructions.

[0087] In some implementations, each controller in the system (e.g., a dedicated inverter rectifier processor, or a dedicated TMN processor, or a dedicated transmitter or receiver processor) may include a bidirectional manager. The bidirectional manager can act as a top-level manager.

[0088] In general, assigning personalities to components / controllers can allow for modularity, non-redundant parts, code, and memory, enabling faster and on-the-fly switching from G2V (grid-vehicle power flow) to V2G (vehicle-to-grid power flow) and vice versa.

[0089] FIG. 8 illustrates a flowchart of an example bidirectional control process 800 that may be performed according to an embodiment of the present disclosure. The example process 800 may be implemented, for example, by the example wireless power system disclosed herein. For example, the process 800 may be performed between a bidirectional manager of the transmitter wireless power device 700a and a bidirectional manager of the receiver wireless power device 700b. The process 800 shows a split primary side operation 802 and a secondary side operation 804. In general, the primary side operation 802 is performed by the receiver wireless power device 700b, and the secondary side operation 704 is performed by the transmitter wireless power device 700a. For example, the receiver (or device side) wireless power device 700b may be coupled to a smaller capacity or more limited power source or load in general. Implementing the receiver wireless power device 700b as a primary device may provide more precise control of the bidirectional control process 800 to prevent exceeding the possible lower limit operation of the Rx side system or its load / power source. In some examples, the exemplary process 800 may be provided by one or more computer-executable programs executed using one or more computing devices, processors, or microcontrollers. For example, the exemplary process 800, or portions thereof, may be provided by one or more programs executed by control circuitry of the wireless power devices 700a, 700b.

[0090] The primary device initiates a power flow transition within the wireless power system. Initiation may be prompted by a user input or, in some implementations, by an automatic power transition decision performed by the primary device (806). For example, the primary device may decide to shift the power flow based on various criteria, including, but not limited to, the battery's state of charge, the time of day, and the availability and / or demand of grid power. For example, the Rx-side wireless power device 700b may be configured to initiate a power flow reversal process when a connected battery exceeds a threshold charge level and a loss of grid power occurs. As another example, the Rx-side wireless power device 700b may be configured to initiate a power flow reversal process when a connected battery exceeds a threshold charge level and during a pre-set time of day. For example, the Rx-side wireless power device 700b may be configured for power flow reversal to provide additional power to a home during peak load periods of the power grid (e.g., periods of high demand and / or high energy prices such as early evenings). In some implementations, the secondary device may determine when to initiate a power flow transition, but may perform additional steps to request the primary device to initiate the power flow transition.

[0091] The primary device sends a command to the secondary device to reverse the direction of power flow (808). In response to the command, the secondary device reconfigures (810) to operate in a power flow direction opposite to its current operation. For example, if the secondary device was operating as a transmitter, it reconfigures to operate as a receiver. If the secondary device was operating as a receiver, it reconfigures to operate as a transmitter. For example, the bidirectional manager of the secondary device can coordinate controller operation in the secondary device to shut down the current direction of power flow, for example, by ensuring operation of an inverter rectifier, shifting switches to disconnect loads / sources (if necessary), toggling bypass switches to dissipate residual current in the secondary device, or a combination thereof.

[0092] The secondary device assigns new operating personalities according to the new power flow direction (812). For example, the bidirectional manager of the secondary device assigns new operating personalities to each controller in the secondary device appropriately for the new direction of power flow. The bidirectional power manager can assign the new operating personalities by toggling a flag bit (e.g., TMN_SIDE, discussed in more detail below) to indicate operation as a transmitter / inverter or as a receiver / rectifier.

[0093] In response to the assignment of the new operating personality, the various secondary device controllers can reconfigure their respective operations. For example, the controllers can load control algorithms (e.g., software code blocks) to implement operation with the new power flow direction. For example, the TMN controller can reset the TMN and load control codes to generate appropriate TMN control signals for operation with the new power flow direction. The TMN may need to adjust setpoints (e.g., impedance values, impedance adjustment step sizes, and / or protection schemes) to accommodate power transfer in the new direction, or to prepare for increased power in the new direction, or both. For example, the power flow in V2G mode may generally be lower than the power flow in G2V mode, e.g., due to asymmetry between the GA-side resonator coils and the VA-side resonator coils and / or battery discharge constraints. As a result, the TMN and / or inverter rectifier setpoints may differ for operation in V2G mode and G2V mode.

[0094] The secondary device (e.g., the inverter controller of the secondary device) may control the inverter rectifier operation according to the new operating personality (814). For example, the inverter rectifier controller may be loaded with an appropriate algorithm to generate PWM control signals to operate as an inverter when the secondary device is a transmitter and as a rectifier when the secondary device is a receiver. The specific inverter and rectifier operations are described in more detail below with reference to Figures 9 and 10.

[0095] The secondary device sends a response to the primary device indicating the reconfiguration status of the secondary device (816). If the secondary device indicates that the reconfiguration of the secondary device is still in progress or has stopped, the primary device waits and / or resends the instruction 808. By waiting for confirmation that the secondary device has completed updating the secondary device's operating personality, the process 800 may provide safer and more robust operation. For example, this may prevent power flow from starting or reversing with incompatible personalities assigned to either the secondary or primary device. Once the secondary device indicates that the reconfiguration of the secondary device is complete, the primary device reconfigures (818) to operate in a power flow direction opposite its current operation. For example, if the primary device was operating as a transmitter, it reconfigures to operate as a receiver. If the primary device was operating as a receiver, it reconfigures to operate as a transmitter. For example, the bidirectional manager of the primary device can coordinate controller action in the secondary device to shut down the current direction of power flow, such as by ensuring operation of an inverter rectifier, shifting switches to disconnect loads / sources (if necessary), toggling bypass switches to dissipate residual current in the secondary device, or a combination thereof.

[0096] The primary device assigns new operating personalities according to the new power flow direction (820). For example, the bidirectional manager of the primary device assigns new operating personalities to each controller in the primary device appropriately for the new direction of power flow. The bidirectional (power) manager can assign new operating personalities by toggling a flag bit (e.g., TMN_SIDE, discussed in more detail below) to indicate operation as a transmitter / inverter or as a receiver / rectifier.

[0097] In response to the assignment of the new operational personality, the various primary device controllers can reconfigure their respective operations. For example, the controllers can load control algorithms (e.g., software code blocks) to implement operation with the new power flow direction. For example, the TMN controller can reset the TMN and load control codes to generate appropriate TMN control signals for operation with the new power flow direction. The TMN may need to adjust setpoints (e.g., impedance values ​​and / or protection schemes) to accommodate power transfer in the new direction, or to prepare for increased power in the new direction, or both.

[0098] The primary device (e.g., the inverter controller of the primary device) can control the inverter rectifier operation according to the new operating personality (822). For example, the inverter rectifier controller can be loaded with an appropriate algorithm to generate a PWM control signal to operate as an inverter when the secondary device is a transmitter and as a rectifier when the secondary device is a receiver. In some implementations, the TMN controller in the primary device can control the TMN according to the new operating personality. For example, the TMN controller on the primary device can be loaded with an appropriate control algorithm to generate a TMN regulation signal to operate as a load coupled to the TMN in a first direction or as a power source coupled to the TMN in a second direction.

[0099] 9 shows a schematic diagram 900 of an example inverter rectifier 902 and a timing diagram 902 illustrating the operation of the inverter rectifier in an inverter mode of operation. The schematic diagram 1800 shows a phase-shifted full-bridge inverter. The inverter bridge circuit uses active switching elements Q1, Q2, Q3, and Q4, which may be, for example, MOSFETs, transistors, FETs, IGBTs, etc.

[0100] Timing diagram 902 shows the drive signal pattern for switches Q1, Q2, Q3, and Q4. The switches are grouped into two legs: leg A (Q1, Q3) and leg B (Q2, Q4). The corresponding switches in each leg are alternately turned on and off by respective PWM control signals. The on-time and off-time of each gate drive signal G1, G2, G3, and G4 are shown. A dead time td is shown when both gate drives of the same leg are off. The off-time may be greater than the on-time of each drive signal of duration Ts.

[0101] The delay time tps between leg A (Q1 and Q3) and leg B (Q2 and Q4), when expressed in degrees, is known as the phase shift angle and is a means of adjusting the overall power delivered by the inverter rectifier when operating as an inverter. At start-up, the output power VAB(t) from the inverter rectifier terminals VA and VB may have an 11% duty cycle (leg phase shift angle θps = 20 degrees). At maximum power, VAB(t) may be a 100% duty cycle (leg phase θps = 180 degrees). The total power output is controlled by adjusting the delay time tPS between the leg A PWM signal and the leg B PWM signal.

[0102] In some embodiments, the inverter rectifier 900 may operate according to one or more active rectification methods described herein (e.g., methods 304, 402, 502, and / or 602). Although a full-bridge inverter is shown, in some implementations, the inverter rectifier switches may be arranged in a half-bridge configuration. In some implementations, the inverter rectifier may implement zero-voltage switching operation to ensure that the switches operate when the voltage across them is zero or near zero.

[0103] FIG. 10 shows an example inverter rectifier schematic 1000 and a timing diagram 1902 showing the operation of the inverter rectifier 702 in a rectifier operating mode. FIG. 10 illustrates a synchronous rectifier operation utilizing the same switches as shown in FIG. 9. The gate drive signals (G1, G2, G3, G4) corresponding to each switch (Q1, Q2, Q3, Q4) are shown in the timing diagram 1902. Although zero current switching operation is shown, zero voltage switching (ZVS) necessarily follows this operation and may be used in some implementations. However, ZVS switching in active rectification mode is not shown in the drawings.

[0104] The synchronous rectifier can receive the zero crossings of the I3s current (shown as I3d or I3s in FIG. 7) and create the timing of synchronous rectification (zero current switching) as shown in timing diagram 1002. In rectifier mode, the inverter rectifier 702 rectifies the AC input signal to a DC output signal by alternately turning on the corresponding switch pairs (Q1 / Q4 and Q2 / Q3). For example, the inverter rectifier controller (e.g., inverter / protection and control circuit) can receive I3d or I3s current and / or phase measurements from a current sensor or phase sensor (e.g., sensor 218). The switches Q1, Q2, Q3, and Q4 can be turned off at zero current (or near zero current) at the input to the inverter rectifier 702, and the next switch pair (e.g., Q1 and Q4, or Q2 and Q3) can be operated after an appropriate time delay td has elapsed. This can prevent power loss in the switches. In some implementations, the time delay can be adjusted by the system as needed.

[0105] In some implementations, during start-up, the inverter rectifier does not begin switching until the measured input power exceeds a threshold that ensures continuous conduction of the I3d current. The threshold may be, for example, 2 kW to 4 kW, and / or 20 to 40% of the target power. During low power operation below the threshold input power value, the input AC signal may be noisy, resulting in inaccurate zero-crossing detection and possibly large transients for inaccurate switching. For example, the I3d current used to generate the PWM synchronization may be discontinuous and noisy, which may result in inaccurate zero-crossing detection and possibly large transients, or even destructive shorting of the power stage. Instead, rectification may be performed passively when the power falls below the threshold by conduction through the body diodes of the switches. In such implementations, switching operations performed above the threshold input power value may be considered an active rectification mode, and body diode conduction below the threshold input power value may be considered a passive rectification mode.

[0106] In some embodiments, the inverter rectifier 1000 may operate according to one or more of the active rectification methods described herein (eg, methods 304, 402, 502, and / or 602).

[0107] Hardware and Software Implementation In some examples, some or all of the above-mentioned processing may be performed on one or more centralized computing devices. In some examples, some types of processing occur on one device and other types of processing occur on another device. In some examples, some or all of the above-mentioned data may be stored in data storage hosted on one or more centralized computing devices or via cloud-based storage. In some examples, some data is stored in one location and other data is stored in another location. In some examples, quantum computing may be used. In some examples, functional programming languages ​​may be used. In some examples, electrical memory, such as flash-based memory, may be used.

[0108] FIG. 11 is a block diagram of an exemplary computer system 1100 that may be used to implement the techniques described in this document. A general purpose computer, a network appliance, a mobile device, or other electronic system may also include at least a portion of the system 1100. The system 1100 includes a processor 1110, a memory 1120, a storage device 1130, and an input / output device 1140. Each of the components 1110, 1120, 1130, and 1140 may be interconnected using, for example, a system bus 1150. The processor 1110 may process instructions for execution within the system 1100. In some implementations, the processor 1110 is a single-threaded processor. In some implementations, the processor 1110 is a multi-threaded processor. The processor 1110 may process instructions stored in the memory 1120 or on the storage device 1130.

[0109] The memory 1120 stores information within the system 1100. In some implementations, the memory 1120 is a non-transitory computer-readable medium. In some implementations, the memory 1120 is a volatile memory unit. In some implementations, the memory 1120 is a non-volatile memory unit.

[0110] The storage device 1130 can provide mass storage for the system 1100. In some implementations, the storage device 1130 is a non-transitory computer-readable medium. In various different implementations, the storage device 1130 may include, for example, a hard disk device, an optical disk device, a solid-state drive, a flash drive, or some other mass storage device. For example, the storage device may store long-term data (e.g., database data, file system data, etc.). The input / output device 1140 provides input / output operations for the system 1100. In some implementations, the input / output device 1140 may include one or more of a network interface device, e.g., an Ethernet card, a serial communication device, e.g., an RS-232 port, and / or a wireless interface device, e.g., an 802.11 card, a 3G wireless modem, or a 4G wireless modem. In some implementations, the input / output device may include a driver device configured to receive input data and send output data to other input / output devices, e.g., a keyboard, a printer, and a display device 1160. In some examples, mobile computing devices, mobile communication devices, and other devices may be used.

[0111] In some implementations, at least a portion of the above-described approaches may be realized by instructions that, when executed, cause one or more processing devices to perform the processes and functions described above. Such instructions may include, for example, script instructions, or interpreted instructions such as executable code, or other instructions stored on a non-transitory computer-readable medium. The storage device 1130 may be implemented in a distributed manner across a network, such as a server farm or a widely distributed set of servers, or may be implemented in a single computing device.

[0112] Although an exemplary processing system is described in FIG. 11, the embodiments, functional operations and processes of the subject matter described herein may be implemented in other types of digital electronic circuitry, tangibly embodied computer software or firmware, computer hardware, or one or more combinations thereof, including the structures disclosed herein and their structural equivalents. The embodiments of the subject matter described herein may be implemented as one or more computer programs, i.e., one or more modules of computer program instructions encoded on a tangible non-volatile program carrier for execution by or control of the operation of a data processing apparatus. Alternatively or additionally, the program instructions may be encoded in an artificially generated propagated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal generated to encode information for transmission to a receiving device suitable for execution by a data processing apparatus. The computer storage medium may be a machine-readable storage device, a machine-readable storage substrate, a random or serial access memory device, or one or more combinations thereof.

[0113] The term "system" may encompass any kind of apparatus, device, and machine for processing data, including, by way of example, a programmable processor, a computer, or multiple processors or computers. A processing system may include application-specific logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application-specific integrated circuit). In addition to hardware, a processing system may include code that creates an execution environment for the computer program in question, such as code that constitutes processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of these.

[0114] A computer program (which may also be referred to or described as a program, software, software application, module, software module, script, or code) may be written in any form of programming language, including compiled or interpreted languages, or declarative or procedural languages, and the computer program may be deployed in any form, including as a stand-alone program or as a module, component, subroutine, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program may be stored in the form of a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), a single file dedicated to the program in question, or multiple interlocking files (e.g., a file that stores one or more modules, subprograms, or portions of code). A computer program may be deployed to run on one computer or multiple computers that are located at one location or distributed across multiple locations and interconnected by a communications network.

[0115] The processes and logic flows described herein may be performed by one or more programmable computers executing one or more computer programs to perform functions by operating on inputting data and generating output. The processes and logic flows may also be performed by, and an apparatus may be implemented as, special purpose logic circuitry, such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0116] A computer suitable for executing a computer program may include, by way of example, a general-purpose or special-purpose microprocessor or both, or any other type of central processing unit. Typically, the central processing unit receives instructions and data from a read-only memory or a random access memory or both. A computer typically includes a central processing unit for implementing or executing instructions, and one or more memory devices for storing instructions and data. Typically, a computer includes or is operatively coupled to one or more mass storage devices, such as magnetic disks, magneto-optical disks, or optical disks, for storing data, and receives data from or transmits data to them, or both. However, a computer need not have such devices.

[0117] Computer-readable media suitable for storing computer program instructions and data include all forms of non-volatile memory, media, and memory devices, including, by way of example, semiconductor memory devices, such as EPROM, EEPROM, and flash memory devices, magnetic disks, such as internal hard disks or removable disks, magneto-optical disks, and CD-ROM and DVD-ROM disks. The processor and memory may be supplemented by, or incorporated in, special purpose logic circuitry.

[0118] An embodiment of the subject matter described herein can be implemented in a computing system that includes a back-end component, e.g., a data server, or includes a middleware component, e.g., an application server, or includes a front-end component, e.g., a client computer having a graphical user interface or web browser that allows a user to interact with an implementation of the subject matter described herein, or includes any combination of one or more such back-end, middleware, or front-end components. The components of the system can be interconnected by any form or medium of digital data communication, e.g., a communication network. Examples of communication networks include local area networks ("LANs") and wide area networks ("WANs"), e.g., the Internet.

[0119] A computing system may include clients and servers. Clients and servers are generally remote from each other and typically interact through a communication network. The relationship of client and server arises by virtue of computer programs running on the respective computers and having a client-server relationship to each other.

[0120] Although this specification contains many specific implementation details, these should not be interpreted as limitations on the scope that may be claimed, but rather as descriptions of features that may be specific to a particular embodiment. Certain features described in this specification in the context of separate embodiments may be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination. Furthermore, even if features are described above as acting in a particular combination and initially claimed as such, one or more features from the claimed combination may in some cases be excluded from the combination, and the claimed combination may be directed to a subcombination or a variation of the subcombination.

[0121] Similarly, although operations are shown in the figures in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown or in a sequential order to achieve desirable results, or that all of the illustrated operations be performed. In certain situations, multitasking and parallel processing may be advantageous. Furthermore, the separation of various system components in the above-described embodiments should not be understood as requiring such separation in all embodiments, and it should be understood that the described program components and the described systems may generally be integrated together in a single software product or packaged in multiple software products.

[0122] Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the appended claims. For example, the actions recited in the claims may be performed in a different order and still achieve desirable results. As an example, the processes illustrated in the accompanying drawings do not necessarily require the particular order shown or sequential order to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous. Other steps or stages may be provided, or steps or stages may be eliminated, from the processes described. Accordingly, other implementations are within the scope of the appended claims.

[0123] term The phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting.

[0124] The term "approximately," the phrase "approximately equal," and other similar phrases used in the specification and claims (e.g., "X has a value of approximately Y" or "X is approximately equal to Y") should be understood to mean that one value (X) is within a given range of another value (Y). The given range may be plus or minus 20%, 10%, 5%, 3%, 1%, 0.1%, or less than 0.1%, unless otherwise indicated.

[0125] The indefinite articles "a" and "an" as used herein and in the claims should be understood to mean "at least one" unless clearly indicated to the contrary. The phrase "and / or" as used herein and in the claims should be understood to mean "either or both" of the elements so conjoined, i.e., elements that are conjunctively present in some cases and disjunctively present in other cases. Multiple elements listed with "and / or" should be interpreted in the same manner, i.e., "one or more" of the elements so conjoined. Other elements other than the elements specifically identified by the "and / or" clause may optionally be present, whether or not related to those elements specifically identified. Thus, as a non-limiting example, a reference to "A and / or B", when used in conjunction with open-ended language such as "comprises", may refer in one embodiment to only A (optionally including elements other than B), in another embodiment to only B (optionally including elements other than A), in yet another embodiment to both A and B (optionally including other elements), and so forth.

[0126] As used herein and in the claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items within a list, "or" or "and / or" should be interpreted as inclusive, i.e., including at least one of, but also including more than one, and optionally including additional items not listed. Only terms expressly indicated to the contrary, such as "only one of," or "exactly one of," or "consisting of," when used in the claims, refer to the inclusion of exactly one element of, or a list of elements. In general, the term "or" as used shall be interpreted as indicating exclusive alternatives (i.e., "one or the other, but not both") only when preceded by an exclusive term, such as "either," "one of," "only one of," or "exactly one of." When used in the claims, "consisting essentially of" shall have its ordinary meaning as used in the field of patent law.

[0127] As used herein and in the claims, the phrase "at least one" in reference to a list of one or more elements should be understood to mean at least one element selected from any one or more of the elements in the list of elements, but not necessarily including at least one of each and every element specifically listed in the list of elements, and not excluding any combination of elements in the list of elements. This definition also allows for the optional presence of elements other than those specifically identified in the list of elements to which the phrase "at least one" refers, whether or not related to those specifically identified elements. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B" or, equivalently, "at least one of A and / or B") can refer in one embodiment to including at least one A, optionally more than one A, in the absence of B (and optionally including elements other than B), in another embodiment to including at least one B, optionally more than one B, in the absence of A (and optionally including elements other than A), and in yet another embodiment to including at least one A, optionally more than one A, and at least one B, optionally more than one B (and optionally including other elements).

[0128] The use of "including," "comprising," "having," "containing," "involving," and variations thereof are meant to encompass the items listed before it as well as additional items.

[0129] The use of ordinal terms such as "first," "second," "third," etc. to modify claim elements in the claims does not, by itself, imply any importance, priority, or order of one claim element relative to another claim element, or the temporal order in which method operations are performed. For purposes of distinguishing claim elements, the ordinal terms are used merely as labels to distinguish one claim element having a particular name from another claim element having the same name (absent the use of the ordinal terms).

Claims

1. 1. A method for operating an inverter rectifier of a bidirectional wireless power transmitter, the method comprising: determining a power flow direction of the bidirectional wireless power transmitter; in response to determining that the power flow direction is a first power flow direction, controlling the inverter rectifier to operate in a rectifier mode; generating, during the rectifier mode, a zero-crossing signal representative of one or more zero crossings of a current at an input of the inverter rectifier, a rising edge of the zero-crossing signal indicating a zero crossing corresponding to a rising edge in the current and a falling edge of the zero-crossing signal indicating a zero crossing corresponding to a falling edge in the current; determining a first delay time during the rectifier mode based on at least one bidirectional wireless power transmitter parameter and the zero-crossing signal, the at least one bidirectional wireless power transmitter parameter being determined based on at least one of: (i) an impedance of the inverter rectifier; and (ii) a power level delivered to a load coupled to the bidirectional wireless power transmitter; generating first and second control signals for a first switch and a second switch of the inverter rectifier, respectively, based on the first delay time and the rising and falling edges of the zero-crossing signal during the rectifier mode; providing the first control signal and the second control signal to the first switch and the second switch, respectively, during the rectifier mode; A method comprising:

2. 2. The method of claim 1, further comprising inserting a first dead time between the first control signal and the second control signal during the rectifier mode.

3. determining a second delay time based on the at least one bidirectional wireless power transmitter parameter and the zero-crossing signal; generating third and fourth control signals for a third and fourth switch of the inverter rectifier based on the second delay time and the rising and falling edges of the zero-crossing signal, respectively; providing the third control signal and the fourth control signal to the third switch and the fourth switch, respectively; The method of claim 1 further comprising:

4. The method of claim 3 , further comprising inserting a second dead time between the third control signal and the fourth control signal during the rectifier mode.

5. The method of claim 3 , wherein the third switch and the fourth switch are coupled to the first switch and the second switch in a full-bridge configuration.

6. 2. The method of claim 1 , wherein the first switch and the second switch are operated during the rectifier mode to provide DC power to a voltage bus of the bidirectional wireless power transmitter, the voltage bus being configured to provide received DC power to one of a power source or a load.

7. 2. The method of claim 1, further comprising: in response to determining that the power flow direction is a second power flow direction, controlling the inverter rectifier to operate in an inverter mode.

8. 8. The method of claim 7, wherein the first switch and the second switch are operated to provide AC power to at least one coil of the bidirectional wireless power transmitter during the inverter mode.

9. The method of claim 1 , wherein determining the power flow direction of the bidirectional wireless power transmitter comprises receiving an indication of the power flow direction from a controller of the bidirectional wireless power transmitter.

10. The method of claim 1 , wherein determining the power flow direction of the bidirectional wireless power transmitter comprises receiving an indication of the power flow direction from a wireless power receiver.

11. An inverter rectifier for a bidirectional wireless power transmitter, comprising: a first switch and a second switch coupled to at least one coil of the bidirectional wireless power transmitter; a control system coupled to each of the first switch and the second switch; Equipped with The control system includes: determining a power flow direction of the bidirectional wireless power transmitter; in response to determining that the power flow direction is a first power flow direction, controlling the inverter rectifier to operate in a rectifier mode; generating, during the rectifier mode, a zero-crossing signal representative of one or more zero crossings of a current at an input of the inverter rectifier, a rising edge of the zero-crossing signal indicating a zero crossing corresponding to a rising edge in the current and a falling edge of the zero-crossing signal indicating a zero crossing corresponding to a falling edge in the current; determining a first delay time during the rectifier mode based on at least one bidirectional wireless power transmitter parameter and the zero-crossing signal, the at least one bidirectional wireless power transmitter parameter being determined based on at least one of: (i) an impedance of the inverter rectifier; and (ii) a power level delivered to a load coupled to the bidirectional wireless power transmitter; generating first and second control signals for a first switch and a second switch of the inverter rectifier, respectively, based on the first delay time and the rising and falling edges of the zero-crossing signal during the rectifier mode; providing the first control signal and the second control signal to the first switch and the second switch, respectively, during the rectifier mode; The inverter rectifier is configured to:

12. The control system includes: The inverter rectifier of claim 11 , further configured to insert a first dead time between the first control signal and the second control signal during the rectifier mode.

13. The control system includes: determining a second delay time based on the at least one bidirectional wireless power transmitter parameter and the zero-crossing signal; generating third and fourth control signals for a third and fourth switch of the inverter rectifier based on the second delay time and the rising and falling edges of the zero-crossing signal, respectively; providing the third control signal and the fourth control signal to the third switch and the fourth switch, respectively; The inverter rectifier of claim 11 further configured to:

14. The control system includes: The inverter rectifier of claim 13 , further configured to insert a second dead time between the third control signal and the fourth control signal during the rectifier mode.

15. The inverter rectifier of claim 13 , wherein the third switch and the fourth switch are coupled to the first switch and the second switch in a full-bridge configuration.

16. 12. The inverter rectifier of claim 11, wherein the first switch and the second switch are operated during the rectifier mode to provide DC power to a voltage bus of the bidirectional wireless power transmitter, the voltage bus being configured to provide received DC power to one of a power source or a load.

17. The inverter rectifier of claim 11 , further comprising: in response to determining that the power flow direction is a second power flow direction, controlling the inverter rectifier to operate in an inverter mode.

18. The inverter rectifier of claim 17 , wherein the first switch and the second switch are operated to provide AC power to the at least one coil during the inverter mode.

19. 12. The inverter rectifier of claim 11, wherein determining the power flow direction of the bidirectional wireless power transmitter includes receiving an indication of the power flow direction from a controller external to the control system of the inverter rectifier.

20. The inverter rectifier of claim 11 , wherein determining the power flow direction of the bidirectional wireless power transmitter comprises receiving an indication of the power flow direction from a wireless power receiver.

Images