Detailed Description
The following disclosure provides many different embodiments, or examples, for implementing different features of the provided subject matter. To simplify the present disclosure, specific examples of components and arrangements are described below. These are, of course, merely examples and are not intended to be limiting. For example, formation of a first feature over or on a second feature in the description that follows may include embodiments in which the first and second features are formed in direct contact, and may also include embodiments in which additional features may be formed between the first and second features, i.e., the first and second features may not be in direct contact. Further, the present disclosure may repeat reference numerals and/or letter abbreviations in the various examples. This repetition is for the purpose of simplicity and clarity and does not in itself dictate a relationship between the various embodiments and/or configurations discussed.
The present disclosure describes exemplary rectification circuits (or Alternating Current (AC) to Direct Current (DC) converters) that use active switches for rectification, and describes exemplary DC power generation circuits that include these rectification circuits. In some cases, the active switches may be controlled by signal information relating to the AC voltage signals input to the rectifier circuits, whereby one output terminal of the exemplary rectifier circuit is coupled to one AC voltage signal through one active switch and the other output terminal of the exemplary rectifier circuit is coupled to the other AC voltage signal through the other active switch. In some cases, the AC voltage signal input to the exemplary rectification circuit is generated by the generator, and the active switches of the rectification circuit may be controlled according to the rotor position of the generator.
Fig. 1 is a schematic diagram illustrating an exemplary rectification circuit according to an embodiment of the present disclosure. The rectifier circuit 102 may be used for various applications, such as a vehicle drive system or other type of power system, and may include N input terminals IP1–IPNA pair of output terminals, N first active switches SW11–SWN1N second active switches SW12–SWN2And a control circuit 110, where N is a positive integer greater than 1. N input terminals IP1–IPNIs arranged to receive N AC voltage signals VI, respectively1–VINIn which N AC voltage signals VI1–VINWith different phases. In some cases, the AC voltage signal VI1–VINPossibly provided by a generator or an N-phase generator/alternator (not shown in fig. 1). In some cases, N AC voltage signals VI1–VINMay be the same, but the phase difference between successive phasesIs 360 DEG/N. However, those skilled in the art will appreciate that the N AC voltage signals VI may be used without departing from the spirit and scope of the present disclosure1–VINCan be provided by other types of power supplies, N AC voltage signals VI1–VINMay have different amplitudes and/or the phase difference between successive phases may also be different.
The pair of output terminals includes an output terminal OP1And an output terminal OP2Which is arranged to output a DC voltage signal VO. In some cases, the DC voltage signal VO may be used to charge the battery. In some cases, the DC voltage signal VO may be used as a source voltage to drive electronics and/or mechanical devices (e.g., a motor of a vehicle).
In the embodiment shown in fig. 1, N first active switches SW11–SWN1Configured to receive N control signals CS respectively11–CSN1And according to N control signals CS11–CSN1Will output terminal OP1Are selectively coupled to N input terminals IP respectively1–IPN. For example, a first active switch SW11Is configured to be dependent on the control signal CS11Will output terminal OP1Selectively coupled to input terminals at IP1First active switch SW12Is configured to be dependent on the control signal CS12Will output terminal OP1Selectively coupled to input terminals at IP2And so on. Similarly, N second active switches SW12–SWN2Configured to receive N control signals CS respectively12–CSN2And according to N control signals CS12–CSN2Will output terminal OP2Are selectively coupled to N input terminals IP respectively1–IPN. For example, a second active switch SW12Is configured to be dependent on the control signal CS12Will output terminal OP2Selectively coupled to input terminals IP1Second active switch SW22Is configured to be dependent on the control signal CS22Will output terminal OP2Selectively coupled to input terminals IP2And so on.
In some embodiments, N first active switches SW11–SWN1And N second active switches SW12–SWN2Is a transistor switch. For example, but not limited to, N first active switches SW11–SWN1And N second active switches SW12–SWN2At least one of which may be implemented by a field-effect transistor (FET), a metal-oxide-semiconductor field-effect transistor (MOSFET), an Insulated Gate Bipolar Transistor (IGBT), other types of transistors, or a combination thereof.
The control circuit 110 is coupled to the N first active switches SW11–SWN1And N second active switches SW12–SWN2And is configured to control the N first active switches SW11–SWN1And N second active switches SW12–SWN2The respective switch state. In the embodiment shown in fig. 1, the control circuit 110 is configured to derive the N AC voltage signals VI1–VINGenerating N control signals CS11–CSN1And N control signals CS12–CSN2. In some cases, the control circuit 110 may be configured to determine whether a signal level of the AC voltage signal received at the input terminal is greater than a first preset threshold, wherein when the signal level of the AC voltage signal is greater than the first preset threshold, the control circuit 110 may be configured to turn on a first active switch coupled to the input terminal such that the input terminal may be coupled to the output terminal OP1. For example, when AC voltage signal VI1May be greater than a first predetermined threshold, the control circuit 110 may turn on the first active switch SW11To input terminal IP1Coupled to the output terminal OP1。
Additionally, or alternatively, the control circuit 110 may be configured to determine whether a signal level of the AC voltage signal received at the input terminal is less than a second preset threshold, wherein when the signal level of the AC voltage signal is less than the second preset thresholdIn value, the control circuit 110 may be configured to turn on a second active switch coupled to the input terminal, such that the input terminal may be coupled to the output terminal OP2. For example, when AC voltage signal VI2May be less than a second predetermined threshold, the control circuit 110 may turn on the second active switch SW22To input terminal IP2Coupled to the output terminal OP2. In some embodiments, the second preset threshold may be less than the first preset threshold.
In some embodiments, the control circuit 110 may be configured to turn on the N first active switches SW simultaneously11–SWN1One of them and N second active switches SW12–SWN2One of which is arranged so that a pair of output terminals can be coupled to the N input terminals IP1–IPNThereby outputting a rectified voltage (DC voltage signal VO). Referring to fig. 2, fig. 2 is a schematic diagram illustrating an exemplary switching operation of the rectifier circuit shown in fig. 1 according to an embodiment of the present disclosure. As shown in fig. 2, a first active switch SW11According to a control signal CS11On, the second active switch SW22According to a control signal CS22Is turned on so that a current IOCan be switched on and off by the first active switch SW11Slave output terminal OP1Flows out to be coupled at an output terminal OP1And an output terminal OP2A load (e.g. a battery to be charged, not shown in fig. 2) in between, and through a second active switch SW22Flow to input terminal IP2. The rectified voltage (DC voltage signal VO) may be output from a pair of output terminals accordingly. For example, in some cases, when AC voltage signal VI1Is sufficiently high (e.g. greater than the above-mentioned first preset threshold) and the AC voltage signal VI2Is sufficiently low (e.g., less than the second predetermined threshold), the control circuit 110 may turn on the first active switch SW11And a second active switch SW22。
However, this is for illustrative purposes only and is not meant to limit the present disclosure. In some cases, the control circuit 110 may be configured to determine the N AC voltage signals VI1–VINWhether the signal level of the medium AC voltage signal is greater than N AC voltage signals VI1–VINAnd correspondingly simultaneously turns on the N first active switches SW11–SWN1One of them and N second active switches SW12–SWN2One of them. For example, when AC voltage signal VI1Signal level ratio of the AC voltage signal VI2When the signal level is higher than the preset threshold, the control circuit 110 may turn on the first active switch SW11Thereby inputting the terminal IP1Coupled to the output terminal OP1And turn on the second active switch SW22To input terminal IP2Coupled to the output terminal OP2. Additionally, or alternatively, when the AC voltage signal VI2Signal level ratio of the AC voltage signal VI1Is higher than the preset threshold, the control circuit 110 may turn on the first active switch SW21To input terminal IP2Coupled to the output terminal OP1And turn on the second active switch SW12To input terminal IP1Coupled to the output terminal OP2。
It should be noted that the control circuit 110 may be configured to detect the N AC voltage signals VI directly or indirectly by1–VINRespective signal levels for controlling the N first active switches SW11–SWN1And N second active switches SW12–SWN2The respective switch state. In some embodiments, the control circuit 110 may be configured to receive the N AC voltage signals VI1–VINTo directly detect their respective signal levels to control the N first active switches SW11–SWN1And N second active switches SW12–SWN2The respective switch state. In some embodiments, the control circuit 110 may be configured to receive the N AC voltage signals VI1–VINTo detect their respective phases and thereby determine the N AC voltage signals VI1–VINThe respective signal level. In some embodiments, control circuit 110 may be configured to detect operation of a power supply (not shown in FIG. 2) that provides powerN AC voltage signals VI1–VINThereby indirectly detecting the N AC voltage signals VI1–VINThe respective signal level. For example, but not limiting of, in some cases, N AC voltage signals VI1–VINProvided by a generator (e.g., an alternator), the control circuit 110 may be configured to detect a rotor position of the generator to determine the N AC voltage signals VI1–VINThe respective signal level (or the respective phase). Those skilled in the art will recognize that such equivalent constructions do not depart from the spirit and scope of the disclosure.
By using active switches in the power rectification rather than passive components (e.g., diodes), the rectifier circuit 100 may have high power efficiency. For example, in some cases, the rectifier circuit 100 is applied to a high power vehicle, and the generator of the high power vehicle has 1kW (12V, 83A) of power when the N first active switches SW11–SWN1And N second active switches SW12–SWN2When implemented using transistor switches with an on-state voltage drop of less than 0.1V, the associated power consumption is about 8W (i.e., a rectification efficiency of 99%). Power losses can be greatly reduced.
FIG. 3 is a schematic diagram illustrating an exemplary vehicle drive system according to an embodiment of the present disclosure. The vehicle drive system 300 may include, but is not limited to, a DC power generation circuit 301, a conversion circuit 306, and an engine 308. The DC power generation circuit 301 is configured to output a DC voltage signal VD to the conversion circuit 306, and the conversion circuit 306 is configured to convert the DC voltage signal VD into a plurality of AC voltage signals VM of different phases1–VM3. The motor 308 may be an electric motor or an engine, such as an internal combustion engine (not shown in FIG. 3), and is configured to operate according to the AC voltage signal VM1–VM3And (5) operating.
In the embodiment shown in fig. 3, the DC power generation circuit 301 may include a rectification circuit 302 and a generator 304. The rectifier circuit 302 may represent the exemplary embodiment of the rectifier circuit 102 shown in fig. 1 described above. Thus, a plurality of transistor switches T11–T31May represent the first active switch SW shown in fig. 1 described above11–SWN1In the exemplary embodiment of (i.e., N equals 3 in this embodiment), a plurality of transistor switches T12–T32May represent the second active switch SW shown in fig. 1 described above12–SWN2And control circuit 310 represents the exemplary embodiment of control circuit 110 shown in fig. 1 described above. The control circuit 310 may be configured to be dependent on a plurality of AC voltage signals VE1–VE3Generating a plurality of control signals CG11–CG31And a plurality of control signals CG12–CG32Thereby controlling the transistor switch T11–T31And a transistor switch T12–T32The respective switch state.
The generator 304 may be configured to generate an AC voltage signal VE1–VE3In which the AC voltage signal VE1–VE3The respective phases are different. In the embodiment shown in fig. 3, the generator 304 may be implemented as a three-phase permanent magnet brushless generator. However, those skilled in the art will appreciate that the generator 304 may be implemented by other types of alternators, generators, or brushless generators without departing from the spirit and scope of the present disclosure.
Refer to fig. 4 and 3. FIG. 4 illustrates the AC voltage signal VE shown in FIG. 3 according to an embodiment of the present disclosure1–VE3Control signal CG11–CG31And a control signal CG12–CG32Timing diagram of relative time. For illustrative purposes, in the present embodiment, the AC voltage signal VE1–VE3The phase difference between consecutive phases with the same amplitude is 120. This is not a limitation on the scope of the disclosure.
In the exemplary embodiment shown in fig. 4, when the AC voltage signal (AC voltage signal VE)1– VE3One of them), the control circuit 310 shown in fig. 3 may be configured to switch the transistor T on and off when the signal level of the transistor T is greater than the preset threshold VT111–T31One of them is turned on to connect the input terminal (input terminal IP)1–IP3A corresponding one of) is coupled to the output terminal OP1(ii) a When A is the C voltage signalIs less than a preset threshold VT2, the control circuit 310 shown in fig. 3 may be configured to switch the transistor T on and off12–T32One of which is turned on to couple the input terminal to the output terminal OP2。
For example, when the voltage signal VE1Is greater than a preset threshold VT1, is coupled to the input terminal IP1Transistor switch T of11According to the control signal CG11Turned on (at time point T8); when the voltage signal VE2Is greater than a preset threshold VT1, is coupled to the input terminal IP2Transistor switch T of21According to the control signal CG21Turned on (at time point T1); when the voltage signal VE3Is greater than a preset threshold VT1, is coupled to the input terminal IP3Transistor switch T of31According to the control signal CG31Is turned on (at time point T4). In addition, when the voltage signal VE1Is less than a preset threshold VT2, is coupled to the input terminal IP1Transistor switch T of12According to the control signal CG12Turned on (at time point T2); when the voltage signal VE2Is less than a preset threshold VT2, is coupled to the input terminal IP2Transistor switch T of22According to the control signal CG22Turned on (at time point T6); when the voltage signal VE3Is less than a preset threshold VT2, is coupled to the input terminal IP3Transistor switch T of32According to the control signal CG32Is turned on (at time point T10).
In some cases, when the AC voltage signal (AC voltage signal VE)1–VE3One of the above) is less than a preset threshold VT1, the control circuit 310 shown in fig. 3 may be configured to switch the corresponding transistor (transistor switch T)11–T31One of them) to disconnect the input terminal (input terminal IP)1–IP3Corresponding one) and the output terminal OP1Decoupling; when the signal level of the AC voltage signal is greater than the preset threshold VT2, the control circuit 310 shown in fig. 3 may be configured to switch the corresponding transistor (transistor switch T)12–T32One of them) to disconnect the input terminal from the output terminal OP2And (4) decoupling.
For example, when the voltage signal VE1Is less than a preset threshold VT1, is coupled to the input terminal IP1Transistor switch T of11According to the control signal CG11(at time point T11) open; when the voltage signal VE2Is less than a preset threshold VT1, is coupled to the input terminal IP2Transistor switch T of21According to the control signal CG21(at time point T3) open; when the voltage signal VE3Is less than a preset threshold VT1, is coupled to the input terminal IP3Transistor switch T of31According to the control signal CG31(at time point T7). In addition, when the voltage signal VE1Is greater than a preset threshold VT2, is coupled to the input terminal IP1Transistor switch T of12According to the control signal CG12(at time point T5) open; when the voltage signal VE2Is greater than a preset threshold VT2, is coupled to the input terminal IP2Transistor switch T of22According to the control signal CG22(at time point T9) open; when the voltage signal VE3Is greater than a preset threshold VT2, is coupled to the input terminal IP3Transistor switch T of32According to the control signal CG32(at time point T12).
In the exemplary embodiment shown in fig. 4, the respective sizes of the preset threshold VT1 and the preset threshold VT2 may be the same or substantially the same. However, those skilled in the art will appreciate that the magnitude of the preset threshold VT1 and the magnitude of the preset threshold VT2 may be set according to design requirements without departing from the spirit and scope of the present disclosure.
In some embodiments, the control circuit 310 shown in fig. 3 may be configured to determine the AC voltage signal VE1–VE3Whether the difference between two respective signal levels (and/or respective phases) thereof meets a turn-on criterion and controls the transistor switch T accordingly11–T31And a transistor switch T12–T32Each of which isA switch state. For example, but not limited to, when AC voltage signal VE1Signal level ratio AC voltage signal VE2Is higher than a preset threshold (e.g., between time point T7 and time point T9), the control circuit 310 may determine that the turn-on criterion is met, thus turning on the transistor switch T11To IP the input terminal1Coupled to the output terminal OP1And turning on the transistor switch T22To input terminal IP2Coupled to the output terminal OP2. Additionally, or alternatively, when said AC voltage signal VE2Is higher than the AC voltage signal VE1Is higher than the above-mentioned preset threshold (e.g., between time point T2 and time point T4), the control circuit 310 may determine that the turn-on criterion is fulfilled, and thus turn on the transistor switch T21To IP the input terminal2Coupled to the output terminal OP1And turning on the transistor switch T12To input terminal IP1Coupled to the output terminal OP2。
In some embodiments, the control circuit 310 may detect the phase of the AC voltage signal to determine whether a turn-on criterion is satisfied. For example, but not limited to, when AC voltage signal VE2Is within a first predetermined range (e.g., between time point T1 and time point T3), the control circuit 310 may determine that a turn-on criterion is satisfied, thereby turning on the transistor switch T21To IP the input terminal2Coupled to the output terminal OP1. Additionally, or alternatively, when the AC voltage signal VE2Is within a second predetermined range (e.g., between time T6 and time T9), the control circuit 310 may determine that the turn-on criterion is met, thereby turning on the transistor switch T22To IP the input terminal2Coupled to the output terminal OP2。
In other embodiments, the control circuit 310 may detect operation of the generator 304 as shown in FIG. 3 to determine whether the turn-on criterion is satisfied. Refer to fig. 5 and 3. Fig. 5 illustrates an exemplary implementation of the control circuit 310 shown in fig. 3 according to an embodiment of the present disclosure. In the embodiment shown in FIG. 5, control circuitry 310 may include, but is not limited to, position sensing circuitryA device 512 and a controller 514. Position sensing device 512 is coupled to generator 304 and is configured to detect a rotor position of generator 304 to produce a detection result DR, wherein the rotor position of generator 304 may be used to determine various AC voltage signals (such as AC voltage signal VE shown in FIG. 3) generated by generator 3041–VE3) The phase of (c).
In some cases, the position sensing device 512 may include a plurality of hall effect sensors to detect the rotor position of the generator 304. For example, and without limitation, in certain examples, when generator 304 is implemented as a three-phase brushless generator, position sensing device 512 may include three hall effect sensors, which may be disposed on a stator of the three-phase brushless generator. However, those skilled in the art will appreciate that other position sensing techniques/devices may be used to detect the rotor position of the generator 304 without departing from the spirit and scope of the present disclosure. For example, the control circuit 310 may be configured to measure a current level and a voltage level associated with an AC voltage signal to detect a phase angle of the AC voltage signal, wherein the position sensing device 512 may be omitted.
The controller 514 is coupled to the position sensing device 512 and configured to generate the control signal CG based on the detection result (detective result, DR)11–CG31And CG12–CG32. In some embodiments, the controller 514 may turn on the transistor switch T when the detection result DR indicates that the rotor position is within an angular range11-T31One of the input terminal and the output terminal OP1Coupling; when the detection result DR indicates that the rotor position is within another angular range, the controller 514 may turn on the transistor switch T12-T32The input terminal and the output terminal OP2And (4) coupling. For example, when the detection result DR indicates that the rotor position is within an angular range (e.g., between time T1 and time T3 shown in fig. 4), the controller 514 may turn on the transistor switch T21To input terminal IP2And an output terminal OP1Coupling; when the detection result DR indicates that the rotor position is within another angular range (e.g., between time T6 and time T9 shown in FIG. 4)) When so, the controller 514 may turn on the transistor switch T22To input terminal IP2And an output terminal OP2And (4) coupling.
In some embodiments, the controller 514 may be configured to simultaneously turn on the transistor switches T11-T31One of them and a transistor switch T12-T32One of them. For example, in some cases, the controller 514 may turn on the transistor switch T when the detection result DR indicates that the rotor position is within the first angular range11-T31One of them, to connect the first input terminal (input terminal IP)1–IP3One of them) is coupled to the output terminal OP1And turning on the transistor switch T12-T32One of them, to connect the second input terminal (input terminal IP)1–IP3The other of them) is coupled to an output terminal OP2. Additionally, or alternatively, the controller 514 may turn on the transistor switch T when the detection result DR indicates that the rotor position is within a second angular range different from the first angular range11-T31To couple the second input terminal to the output terminal OP1And turning on the transistor switch T12-T32To couple the first input terminal to the output terminal OP2. In some examples of these cases, IP is included for the input terminal1And IP2When the detection result DR indicates that the rotor position is within an angular range, the controller 514 may turn on the transistor switch T11To input terminal IP1And an output terminal OP1Coupling and turning on the transistor switch T22To input terminal IP2And an output terminal OP2Coupling; when the detection result DR indicates that the rotor position is within another angular range, the controller 514 may turn on the transistor switch T21To IP input terminal2And an output terminal OP1Coupling and turning on the transistor switch T12To input terminal IP1And an output terminal OP2And (4) coupling.
Referring again to FIG. 3, the engine 308 may be started by the control circuit 3And 10, controlling. For example, and without limitation, control circuit 310 may detect a rotor position of motor 308 to control conversion circuit 306 (e.g., using Pulse Width Modulation (PWM) control) to generate AC voltage signal VM1–VM3. After engine 308 (e.g., an internal combustion engine; not shown in FIG. 3) is started, engine 308 may be in an idle state. When the engine 308 is warm, the generator 304 may be loaded without active rectification. First, a current starts to flow to the output terminal OP coupled thereto1And OP2A battery in between. Active rectification may be initiated when the amount of current flowing reaches a predetermined amount. The control circuit 310 may immediately stop active rectification if the current decreases or the motor 308 stalls.
By using active switches in power rectification rather than passive components (e.g., diodes), the exemplary active rectification circuit and associated dc generation circuit can greatly reduce power losses and have high power efficiency. Further, the control of active commutation and engine start can be addressed within the control circuit/unit.
Some embodiments described herein may include a rectifier circuit having N input terminals, a pair of output terminals, N first active switches, N second active switches, and a control circuit. The N input terminals are respectively arranged to receive N Alternating Current (AC) voltage signals having different phases, where N is a positive integer greater than 1. A pair of output terminals having a first output terminal and a second output terminal is configured to output a Direct Current (DC) voltage signal. The N first active switches are configured to receive the N first control signals, respectively, and to selectively couple the first output terminals to the N input terminals, respectively, according to the N first control signals. The N second active switches are configured to receive the N second control signals, respectively, and to selectively couple the second output terminals to the N input terminals, respectively, according to the N second control signals. The control circuit is coupled with the N first active switches and the N second active switches and configured to generate N first control signals and N second control signals from the N AC voltage signals.
Some embodiments described herein may include a Direct Current (DC) power generation circuit having a generator and a rectification circuit. The generator is configured to provide N Alternating Current (AC) voltage signals, where N is a positive integer greater than 1, the N AC voltage signals each having a different phase. The rectification circuit is coupled with the generator and configured to convert the N AC voltage signals generated by the generator into DC voltage signals. The rectifier circuit includes N input terminals, a pair of output terminals, N first active switches, N second active switches, and a control circuit. The N input terminals are arranged to receive N AC voltage signals. The pair of output terminals has a first output terminal and a second output terminal, and is configured to output a DC voltage signal. The N first active switches are configured to receive the N first control signals, respectively, and selectively couple the first output terminals to the N input terminals, respectively, according to the N first control signals, and the N second active switches are configured to receive the N second control signals, respectively, and selectively couple the second output terminals to the N input terminals, respectively, according to the N second control signals. The control circuit is coupled with the N first active switches and the N second active switches and configured to generate N first control signals and N second control signals from the N AC voltage signals.
The foregoing outlines features of some embodiments so that those skilled in the art may better understand the aspects of the present disclosure. Those skilled in the art should appreciate that they may readily use the present disclosure as a basis for designing or modifying other processes and structures for carrying out the same purposes and/or achieving the same advantages of the embodiments introduced herein. Those skilled in the art should also realize that such equivalent constructions do not depart from the spirit and scope of the present disclosure, and that they may make various changes, substitutions, and alterations herein without departing from the spirit and scope of the present disclosure.