TWI802361B - Power conversion and drive system - Google Patents

Abstract

An electric energy conversion and driving system is applicable to an AC power source and a motor, and the motor can be operated in a state of a motor running by consuming electric energy, and a state of a generator generating electric energy by rotating. The electric energy conversion and driving system includes a rectifying unit suitable for being electrically connected with the AC power supply, a driving unit suitable for being electrically connected with the motor, and an energy storage unit electrically connected with the driving unit, and the energy storage unit is used for storing the electric energy generated when the motor is in the generator state, and outputting the electric energy to the drive unit simultaneously with the rectification unit when the motor is in the motor state and the speed increases, so that the rectification unit The power provided by the unit outputs an AC drive power to the motor.

Description

Power conversion and drive system

The present invention relates to an electric energy conversion and drive system, in particular to an electric energy conversion and drive system for driving a motor and capable of storing and reusing the regenerative electric energy generated by the motor.

In the prior art, some drive systems used to drive motors are equipped with energy storage elements (such as capacitors) to store the regenerative electric energy generated by the motor during deceleration, and how to properly use the stored regenerative electric energy to achieve better energy saving Effectiveness has become an issue worthy of study.

Therefore, the object of the present invention is to provide an electric energy conversion and drive system capable of effectively utilizing the regenerative electric energy generated by the motor.

The electric energy conversion and driving system of the present invention is suitable for being electrically connected between an AC power source and a motor, and the motor can operate in a state of a motor running by consuming electric energy, and a state of a generator generating electric energy by rotating. The two periods during which the motor operates in the motor state and the generator state are respectively regarded as a motor period period and a generator period, and the period during which the motor operates in the motor state and the rotation speed increases is regarded as an acceleration operation period included in the motor period. The electric energy conversion and driving system includes: a rectifying unit, a driving unit, an energy storage unit, and a control unit electrically connected to the rectifying unit and the driving unit. The rectifying unit is suitable for being electrically connected with the AC power source. The driving unit is electrically connected to the rectifying unit and is suitable for being electrically connected to the motor. The energy storage unit is electrically connected to the drive unit, and is used to store the electric energy generated by the motor during the generator period as a DC auxiliary electric energy, and discharge it at least during the acceleration operation interval of the motor period, so that the DC Auxiliary power is provided to the drive unit. The control unit is used to: control the rectification unit to generate and output a DC rectified power to the drive unit by using the power provided by the AC power supply during the acceleration operation period of the motor, and control the drive unit to input a DC power Converting into an AC driving electric energy and outputting the AC driving electric energy to the motor. Wherein, the DC input power includes both the DC rectification power and the DC auxiliary power in the acceleration operation range.

In some embodiments of the electric energy conversion and drive system of the present invention, the acceleration operation interval is the period during which the motor speed increases from an initial rotation speed to a target rotation speed during the motor period, and after the acceleration operation interval, The period during which the rotational speed of the motor is maintained within a predetermined rotational speed range covering the target rotational speed is regarded as a constant speed operation interval included in the period of the electric motor; the control unit is also used for: in the constant speed operation interval of the electric motor , the remaining charge in the energy storage unit is higher than a high In the case of the power threshold, the rectification unit is controlled not to output the DC rectified electric energy to the drive unit, so that the energy storage unit continues to discharge during the constant speed operation interval of the motor, and the drive unit only uses the DC Auxiliary electric energy is used as the DC input electric energy to generate the AC driving electric energy; during the constant-speed operation interval of the motor, when the remaining electric quantity of the energy storage unit is lower than a low electric quantity threshold less than the high electric quantity threshold Controlling the rectification unit to output the DC rectified power to the drive unit, so that the energy storage unit stops discharging, and makes the drive unit only use the DC rectified power as the DC input power to generate the AC drive power.

In some embodiments of the electric energy conversion and drive system of the present invention, the electric energy generated when the motor operates in the generator state is used as an AC regenerative electric energy; the control unit is also used for: during the generator period, control The drive unit receives the AC regenerative power, converts the AC regenerative power into a DC regenerative power, and outputs the DC regenerative power to the energy storage unit for the energy storage unit to store the DC regenerative power as the DC auxiliary electrical energy.

In some implementation aspects of the electric energy conversion and drive system of the present invention, the motor is periodically switched between the motor state and the generator state; the drive unit converts the DC input power into the AC drive power and outputs The operating state of the motor is regarded as a first operating state of the driving unit, and the operating state of the driving unit converting the AC regenerative electric energy into the DC regenerative electric energy output to the energy storage unit is regarded as a second operating state of the driving unit working status, and, the control unit is based on the The driving unit is controlled to switch periodically and repeatedly between the first working state and the second working state according to the respective time lengths of the motor period and the generator period.

The invention also provides another electric energy conversion and drive system.

Another electric energy conversion and driving system of the present invention is suitable for being electrically connected between an AC power source and a motor capable of operating in a state of a motor running by consuming electric energy, and a motor generating electric energy by rotating Generator status. The two periods during which the motor operates in the motor state and the generator state are respectively referred to as a motor period and a generator period, and the period during which the motor operates in the motor state and the speed rises is included as a period in the motor During the accelerated operation interval. The electric energy conversion and drive system includes a rectification unit, a drive unit, a switch unit, an energy storage unit, and a control unit electrically connected to the switch unit and the drive unit. The rectifying unit is suitable for being electrically connected with the AC power supply, and is used for generating and outputting a DC rectified electric energy using the electric energy provided by the AC power supply. The driving unit is electrically connected to the rectifying unit and is suitable for being electrically connected to the motor. The switch unit includes a first terminal electrically connected to the drive unit, and a second terminal. The energy storage unit is electrically connected to the second end of the switch unit, and is used for storing the electric energy generated by the motor during the generator period as a DC auxiliary electric energy, and discharging it at least during the acceleration operation interval of the electric motor , so that the DC auxiliary power is provided to the drive unit through the switch unit. The control unit is used for: controlling the first end and the second end of the switch unit to be electrically connected to each other during the acceleration operation interval of the electric motor so that the DC auxiliary power is transferred from the The energy storage unit is provided to the drive unit through the switch unit, and controls the drive unit to convert a DC input power into an AC drive power and output the AC drive power to the motor. Wherein, the DC input power includes both the DC rectification power and the DC auxiliary power in the acceleration operation range.

In some implementation forms of the electric energy conversion and drive system of the present invention, the acceleration operation interval is the period during which the motor speed increases from an initial speed to a target speed during the motor period, and during the acceleration After the running interval, the period during which the rotational speed of the motor is maintained within a predetermined rotational speed range covering the target rotational speed is regarded as a constant-speed operating interval included in the electric motor period. The control unit is also used for controlling the first terminal and the second terminal of the switch unit when the remaining power of the energy storage unit is higher than a high power threshold during the constant speed operation interval of the electric motor. Terminals continue to be electrically connected to each other, so that the DC auxiliary power continues to be supplied from the energy storage unit to the drive unit through the switch unit; during the constant speed operation period of the motor, the remaining power of the energy storage unit is lower than In the case of a low power threshold smaller than the high power threshold, the first end and the second end of the switch unit are controlled to be electrically disconnected, so that the energy storage unit stops outputting the DC auxiliary power.

In some embodiments of the other electric energy conversion and driving system of the present invention, the switch unit is a bidirectional voltage conversion unit, the first terminal is a high-voltage side connection terminal of the bidirectional voltage conversion unit, and the second The end is a low-voltage side connection end of the bidirectional voltage conversion unit. When the bidirectional voltage conversion unit operates in a boost working state , the first terminal and the second terminal of the switch unit are electrically connected to each other, and the bidirectional voltage conversion unit receives the DC auxiliary power from the energy storage unit through the low-voltage side connection terminal, and performs a step-up processing, and output the DC auxiliary power after the step-up processing to the drive unit through the high-voltage side connection end. During the acceleration operation interval of the electric motor, and in the constant speed operation interval of the electric motor and the remaining power of the energy storage unit is higher than a high power threshold, the control unit is to control the bidirectional voltage conversion unit operating in the boost working state.

In some implementation aspects of the electric energy conversion and driving system of the present invention, the electric energy generated when the motor operates in the generator state is used as an AC regenerative electric energy. The control unit is also used for: controlling the first end and the second end of the switch unit to be electrically connected to each other during the period of the generator, and controlling the drive unit to receive the AC regenerative power and convert the AC regenerative power into A DC regenerative electric energy, and output the DC regenerative electric energy to the energy storage unit through the switch unit, so that the energy storage unit can store the DC regenerative electric energy as the DC auxiliary electric energy.

In some embodiments of the other electric energy conversion and driving system of the present invention, the switch unit is a bidirectional voltage conversion unit, the first terminal is a high-voltage side connection terminal of the bidirectional voltage conversion unit, and the second The end is a low-voltage side connection end of the bidirectional voltage conversion unit. When the bidirectional voltage conversion unit operates in a step-down working state, the first terminal and the second terminal of the switch unit are electrically connected to each other, and the bidirectional voltage conversion unit receives power from the driving unit through the high voltage side connection terminal The DC regeneration The electric energy is subjected to a step-down process on the DC regenerative electric energy, and the DC regenerative electric energy subjected to the step-down processing is output to the energy storage unit through the low-voltage side connection terminal. During the generator period, the control unit controls the bidirectional voltage conversion unit to operate in the step-down working state.

The effect of the present invention is that the electric energy conversion and drive system can use the energy storage unit to store the AC regenerative electric energy generated when the motor is in the generator state as DC auxiliary electric energy, and then when the motor is in the electric motor state and the speed increases At the same time, the energy storage unit and the rectification unit respectively output DC auxiliary power and DC rectification power to drive the motor, so that the power conversion and drive system can not only effectively use the AC regenerative power generated by the motor to reduce the power The overall power consumption of the conversion and drive system can also reduce the current stress that the rectifier unit must bear when the motor speed increases and the power loss of the rectifier unit, so as to achieve better energy-saving benefits.

1: Electric energy conversion and drive system

11: rectifier unit

111: AC input connection terminal

112: DC output connection end

12: Drive unit

121: DC side connection terminal

122: AC side connection terminal

13: Energy storage unit

131: charging and discharging connection terminal

14: Control unit

15: Bidirectional voltage conversion unit

151: High voltage side connection end

152: Low-voltage side connection terminal

10: AC power

20: motor

V _{AC_IN} : AC input voltage

V _{DC_REC} : DC rectified voltage

V _{DC_IN} : DC input voltage

V _{AC_OUT} : AC drive voltage

V _{AC_GEN} : AC regenerative voltage

V _{DC_GEN} : DC regenerative voltage

I ₁ : first current

I ₂ : the second current

I ₃ : the third current

I _GEN : regenerative current

I ₄ : the fourth current

T: duty cycle

T1: Motor period

t11: Acceleration running interval

t12: constant speed operation interval

T2: during generator

S0: initial speed

S1: target speed

Other features and effects of the present invention will be clearly presented in the implementation manner with reference to the drawings, wherein: Fig. 1 is a schematic block diagram illustrating a first embodiment of the electric energy conversion and drive system of the present invention, and the system suitable for use with An AC power supply and a motor that the first embodiment cooperates in operation, and what Fig. 1 depicts is the operation situation when a drive unit included in the first embodiment is operated in a first working state; Fig. 2 is a schematic block diagram illustrating the operation of the first embodiment when the drive unit operates in a second working state; Fig. 3 is a schematic diagram illustrating the variation of the rotational speed of the motor in a working cycle ; Fig. 4 is a schematic block diagram illustrating a third embodiment of the electric energy conversion and drive system of the present invention, and an AC power supply and a motor suitable for cooperating with the third embodiment, and, shown in Fig. 4 is the operating situation of a driving unit included in the third embodiment when operating in the first working state; and FIG. 5 is a block diagram illustrating the third embodiment when the driving unit is operating in the second working state operating conditions at the time.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are denoted by the same numerals. If not specifically defined, the "electrical connection" mentioned in this patent specification generally refers to the "wired electrical connection" between multiple electronic devices/devices/components connected to each other through conductive materials, and the "wired electrical connection" through wireless communication technology. "Radio link" for one-way/two-way wireless signal transmission. On the other hand, the "electrical connection" mentioned in this patent specification also generally refers to the "direct electrical connection" formed by direct connection between multiple electronic equipment/devices/components, and the connection between multiple electronic equipment/devices/components. are also indirectly connected to each other through other electronic equipment/devices/components to form a Formed "indirect electrical connection".

Referring to Fig. 1, a first embodiment of the electric energy conversion and drive system 1 of the present invention is suitable for being electrically connected between an AC power source 10 and a motor 20, and the electric energy conversion and drive system 1 is suitable for utilizing the AC power source 10 The provided electric energy drives the motor 20 to operate.

For the convenience of description, the electric energy provided by the AC power supply 10 is regarded as an AC input electric energy in the application of this embodiment. More specifically, the AC power supply 10 in the application of this embodiment may be, for example, a commercial power supply capable of providing 220 volts of RMS voltage, and the AC input power provided by the AC power supply 10 may be, for example, a single-phase sine wave AC power . However, in different applications of this embodiment, the AC power source 10 can also be, for example, a commercial power supply capable of providing an effective voltage of 110 volts, or an AC power supply device, and the AC input power can also be, for example, a polyphase sine wave Alternating current (such as three-phase sine wave alternating current), and not limited to the application of this embodiment.

In the application environment of this embodiment, the motor 20 is, for example, a three-phase motor used to drive a working device (not shown), and the working device may be, for example, a stamping device, but it is not intended to be limit. Specifically, for example, the motor 20 may be used to drive a slider (not shown) included in the punching equipment to reciprocate up and down to realize the punching operation. Moreover, the motor 20 can operate in a motor state that rotates by consuming electric energy, and a generator state that rotates driven by inertia or other non-electric external force to generate regenerative power. for convenience For description, the regenerative electric energy generated when the motor 20 is in the generator state is used as an AC regenerative electric energy in the application of this embodiment. Moreover, it is added that in other application environments of this embodiment, the motor 20 can also be applied to other types of working equipment, such as lathes, drilling equipment, cutting equipment and lifting equipment, etc., instead of It is limited to the stamping equipment mentioned above.

The power conversion and drive system 1 includes a rectifier unit 11 suitable for electrical connection with the AC power source 10, a drive unit 12 suitable for electrical connection with the motor 20 and also electrically connected with the rectifier unit 11, a drive unit 12 electrically connected with the drive unit 12 and an energy storage unit 13 capable of storing electric energy, and a control unit 14 electrically connected to the rectification unit 11 and the drive unit 12 .

In this embodiment, the rectification unit 11 can be implemented, for example, as an AC/DC converter that uses a plurality of active power switching elements (such as thyristors or MOSFETs) to form a full-wave rectification architecture (such as bridge rectification). Moreover, the rectifying unit 11 includes, for example, two AC input terminals 111 suitable for being electrically connected to the AC power source 10 , and a DC output terminal 112 electrically connected to the driving unit 12 . In this embodiment, the rectifying unit 11 is used to receive the AC input power from the AC power source 10 through the two AC input terminals 111, and convert the AC input power into a DC rectified power, and the DC rectified power output to the driving unit 12 through the DC output connection end 112 . Moreover, in this embodiment, the rectification unit 11 may also be controlled by the control unit 14 not to output the DC rectified electric energy.

In more detail, the control unit 14 may, for example, output a plurality of trigger voltage signals or trigger current signals to the active power switching elements of the rectifier unit 11, thereby controlling the rectifier unit 11 to receive the AC power from the AC power source 10 The AC input power is converted into the DC rectified power, whereby the rectifier unit 11 can convert an AC input voltage V _{AC_IN} (for example: 220 volts) corresponding to the AC input power into a DC corresponding to the DC rectified power rectified voltage V _{DC_REC} . Wherein, the rectification unit 11 outputs the power of the DC rectified electric energy as a rectified output power in this embodiment, and the voltage value of the DC rectified voltage V _{DC_REC} is maintained at a rated DC voltage value (for example: 311 volts) Under ideal conditions, the rectified output power is directly proportional to a first current _I1 flowing out from the DC output connection terminal 112, in other words, the rectified output power varies with the magnitude of the first current _I1 .

It is added that, in other embodiments, the rectification unit 11 can also be realized by other rectification structures such as half-wave rectification or Vienna, and is not limited to the bridge rectification exemplified in this embodiment. On the other hand, if the AC input power provided by the AC power source 10 is a three-phase AC power, the number of AC input connection terminals 111 included in the rectification unit 11 is, for example, three, and is not limited to this embodiment. .

In this embodiment, the drive unit 12 is a bidirectional inverter (also known as Inverter) capable of bidirectional voltage AC-DC conversion, and the drive unit 12 includes, for example, a DC output terminal electrically connected to the rectifier unit 11 112 and the DC side connection end 121 of the energy storage unit 13, three AC side connections suitable for electrically connecting the motor 20 terminal 122 , and a three-phase rectifier bridge circuit (not shown) electrically connected between the DC side connection terminal 121 and the AC side connection terminals 122 . It should be added that the three-phase rectifier bridge circuit is implemented, for example, by a plurality of active power switching elements (such as thyristors or MOSFETs). On the other hand, if the motor 20 is a single-phase motor, the AC side connections The number of ends 122 can be two, but not limited to this embodiment.

The drive unit 12 can be switched between a first working state and a second working state, wherein the first working state is used to convert the DC power received through the DC side connection terminal 121 into AC power and then transmit the The AC side connection terminals 122 are output, and the second working state is used to convert the AC power received through the AC side connection terminals 122 into DC power and then output through the DC side connection terminal 121 .

In more detail, when the drive unit 12 operates in the first working state, the drive unit 12 receives a DC from at least one of the rectifier unit 11 and the energy storage unit 13 through the DC side connection terminal 121 Input electric energy, and convert the DC input electric energy into an AC driving electric energy under the control of the control unit 14, and output the AC driving electric energy to the motor 20 through the AC side connection terminals 122, thereby driving the motor 20 Operates in this motor state. In more detail, as shown in FIG. 1, when the driving unit 12 operates in the first working state, the control unit 14 controls the driving unit 14, for example, by using pulse-width modulation (Pulse-width modulation, PWM for short). The unit 12 converts a received DC input voltage V _{DC_IN} corresponding to the DC input power into an AC driving voltage V _{AC_OUT} corresponding to the AC driving power, thereby converting the DC input power into the AC driving power. Wherein, the AC driving voltage V _{AC_OUT} is, for example, an equivalent three-phase sinusoidal voltage formed by many high-frequency pulse square waves. In addition, the driving unit 12 outputs the power of the AC driving electric energy as a driving output power in this embodiment, and the control unit 14 changes the amplitude and/or of the AC driving voltage V _{AC_OUT} by controlling the driving unit 12, for example. Or sine wave frequency to adjust the size of the driving output power to meet the power requirement of the motor 20 . It should be added that the way the control unit 14 controls the drive unit 12 to convert the DC input power into the AC drive power and the way to adjust the drive output power are achieved using existing technologies and are not the focus of this patent specification, so Its details are not described here.

When the drive unit 12 operates in the second working state and the motor 20 is in the generator state, the drive unit 12 is controlled by the control unit 14 to receive the power from the motor 20 through the AC side connection terminals 122 The AC regenerative power is then converted into a DC regenerative power, and the DC regenerative power is output to the energy storage unit 13 through the DC side connection end 121 . In more detail, as shown in FIG. 2, when the drive unit 12 operates in the second working state, and the motor 20 is in the generator state, the drive unit 12 will use the three-phase rectifier bridge circuit to convert it to A received AC regenerative voltage V _{AC_GEN} corresponding to the AC regenerative power is converted into a pair of DC regenerative voltage V _{DC_GEN} corresponding to the DC regenerative power, thereby converting the AC regenerative power into the DC regenerative power.

The energy storage unit 13 includes, for example, a charge-discharge connection terminal 131 electrically connected to the DC-side connection terminal 121 of the drive unit 12, and a plurality of supercapacitors (not shown) whose positive poles are electrically connected to the charge-discharge connection terminal 131, Moreover, the electric energy stored by the energy storage unit 13 is used as a DC auxiliary electric energy in this embodiment. Wherein, the supercapacitor may also be called an electric double layer capacitor, EDLC for short, and the rated capacitance of each supercapacitor may be, for example, 2.65 farads, but it is not limited thereto. It is added that, in other embodiments, according to the energy storage unit 13’s energy storage requirements and the specifications of the supercapacitors, the number of supercapacitors included in the energy storage unit 13 can also be a single, instead of This example is limited.

For the energy storage unit 13, when the drive unit 12 is operating in the second working state and the motor 20 is in the generator state, as shown in FIG. 2, the energy storage unit 13 can receive the drive unit 12 through the DC regenerative electric energy output by the DC side connection end 121, so that a regenerative current I _GEN flows from the DC side connection end 121 of the driving unit 12 into the charging and discharging connection end 131 of the energy storage unit 13, thereby, The energy storage unit 13 stores the received DC regenerative power as the DC auxiliary power. On the other hand, when the drive unit 12 operates in the first working state and the motor 20 is in the motor state, as shown in FIG. 1 , the energy storage unit 13 can discharge a second current _I2 from the The charge and discharge connection end 131 of the energy storage unit 13 flows into the DC side connection end 121 of the drive unit 12, whereby the DC auxiliary power stored in the energy storage unit 13 is provided to the drive unit 12, so that the drive unit 12 The DC auxiliary power output by the energy storage unit 13 is used as at least a part of the DC input power.

In particular, in this embodiment, when the drive unit 12 is operating in the first working state, the DC input power received by the drive unit 12 is composed of the DC rectified power from the rectifier unit 11 and At least one of the DC auxiliary power from the energy storage unit 13 is formed. More specifically, as shown in FIG. 1, if the rectifying unit 11 is outputting the DC rectified electric energy (that is, the first current _I1 is greater than 0 ampere), and the energy storage unit 13 is also discharging and outputting the DC auxiliary power (that is, the second current I ₂ is greater than 0 ampere), the drive unit 12 will use the DC rectified power received through the DC side connection terminal 121 and the DC auxiliary power together as the DC input power. , the current magnitude of a third current _I3 flowing into the driving unit 12 through the DC side connection terminal 121 is the sum of the first current _I1 and the second current _I2 . On the other hand, if the drive unit 12 does not output the DC rectified power, but the energy storage unit 13 is discharging and outputs the DC auxiliary power, then the drive unit 12 will only use the DC auxiliary power as the DC input power , at this moment, the first current _I1 is substantially 0 ampere, and the magnitude of the third current _I3 is equal to the second current _I2 . On the other hand, if the drive unit 12 is outputting the DC rectified electric energy, but the energy storage unit 13 is not discharging, then the drive unit 12 will only use the DC rectified electric energy as the DC input electric energy. At this time, the The second current I ₂ is substantially 0 ampere, and the magnitude of the third current I ₃ is equal to that of the first current I ₁ .

Referring to Fig. 3, the application of the motor 20 in this embodiment will be described below with Fig. 3 How it works in .

In the application of this embodiment, the rotational speed of the motor 20 is automatically controlled by a programmable motor controller (not shown in the figure), and changes repeatedly with a plurality of working cycles T. FIG. 3 only shows one complete working cycle T, and the working cycle T shown in FIG. 3 is used to illustrate the changing manner of the rotational speed of the motor 20 .

In the duty cycle T of FIG. 3 , the period during which the motor 20 operates in the motor state is referred to as a motor period T1 , and the period during which the motor 20 operates in the generator state is referred to as a generator period T2 . More specifically, in the application of this embodiment, the duty cycle T includes the motor period T1 as shown in FIG. 3 , and the generator period T2 following the motor period T1. It is particularly noted that, in the application of this embodiment, the time lengths of the motor period T1 and the generator period T2 are preset fixed values. Specifically, for example, the time length of the motor period T1 can be, for example, is 3 seconds, and the duration of the generator period T2 can be, for example, 1 second, but it is not limited thereto. Therefore, the motor 20 is equivalent to periodically and repeatedly switching between the motor state and the generator state along with the duty cycles T.

Further, in the motor period T1, the period during which the rotation speed of the motor 20 rises from an initial rotation speed S0 to a target rotation speed S1 is regarded as an acceleration operation interval t11 shown in FIG. 3 , and the rotation speed of the motor 20 reaches the target The period during which the rotational speed S1 is maintained within a predetermined rotational speed range is defined as a constant speed operation interval t12 shown in FIG. 3 . More specifically, the motor period T1 includes the acceleration operation section as shown in FIG. 3 t11, and the constant speed operation interval t12 following the acceleration operation interval t11. Wherein, the initial rotational speed S0, the target rotational speed S1 and the predetermined rotational speed range are all preset. For example, the initial rotational speed S0 may be 0 RPM, the target rotational speed S1 may be 1200 RPM, and the predetermined rotational speed The range can be, for example, a range within plus or minus 5% of the target speed S1 to cover the target speed S1 , but it is not limited thereto.

Then, after the constant-speed operation interval t12 ends, the rotation speed of the motor 20 will drop from the predetermined rotation speed range to the initial rotation speed S0 during the generator period T2, for example, and in the acceleration operation interval t11 of the next duty cycle T It rises from the initial speed S0 to the target speed S1 again. In other words, the speed of the motor 20 changes back and forth between the initial speed S0 and the target speed S1 periodically during the working periods T. In addition, in the application of this embodiment, the time lengths of the acceleration operation interval t11 and the constant speed operation interval t12 are also preset fixed values. Specifically, for example, the time length of the acceleration operation interval t11 may be, for example, 1 second, and the time length of the constant speed operation interval t12 may be, for example, 2 seconds, but it is not limited thereto.

Referring to FIG. 1 and FIG. 3 at the same time, the operation mode of the electric energy conversion and driving system 1 in the working cycle T of FIG. 3 will be described below. Moreover, it is assumed here that the energy storage unit 13 has pre-stored DC auxiliary power when the working cycle T starts.

In this embodiment, the drive unit 12 is in the first working state and the second working state according to the respective time lengths of the motor period T1 and the generator period T2. Switch between working states periodically. More specifically, the driving unit 12 operates in the first working state during the motor period T1, and operates in the second working state during the generator period T2.

First, in the acceleration operation interval t11 of the motor period T1, the control unit 14 controls the rectification unit 11 to continuously convert the AC input power from the AC power source 10 into the DC rectified power, and pass the DC rectified power through the The DC output terminal 112 is output to the driving unit 12 . At the same time, the driving unit 12 continues to operate in the first working state, so as to continuously receive the DC input power through the DC side connection terminal 121, convert the DC input power into the AC driving power, and transmit the AC driving power through the The AC-side connecting terminal 122 is output to the motor 20 .

It is particularly noted that when the rotational speed of the motor 20 increases rapidly, the power it consumes also increases rapidly. Therefore, in the acceleration operation interval t11, the drive output power of the drive unit 12 outputting the AC drive electric energy will increase accordingly. As the rotation speed of the motor 20 increases, a maximum driving output power (for example: 15KW, but not limited thereto) is reached. Furthermore, when the driving output power of the driving unit 12 outputting the AC driving electric energy rises, in transient changes, the third current _I3 will rise with the rising of the driving output power, and the DC side connecting terminal 121 The voltage (that is, the DC input voltage V _{DC_IN} ) will decrease with the increase of the driving output power, and is lower than the voltage of the charging and discharging connection terminal 131 of the energy storage unit 13. In this case, except for the rectifying unit 11 outputs the DC rectified electric energy to the outside of the driving unit 12 , and the energy storage unit 13 also discharges the driving unit 12 through the charging and discharging connection terminal 131 to form the second current I ₂ . Thereby, the DC auxiliary electric energy stored in the energy storage unit 13 will be at least partially provided to the drive unit 12 in the acceleration operation interval t11, so that the energy storage percentage of the energy storage unit 13 itself is within the acceleration operation interval Decline within t11.

Therefore, in the acceleration operation interval t11, the drive unit 12 uses the DC rectified power output by the rectifier unit 11 and the DC auxiliary power output by the energy storage unit 13 as the DC input power to generate and output the AC drive. electrical energy. In other words, in the acceleration operation interval t11, the DC input power received by the drive unit 12 is composed of the DC rectified power and the DC auxiliary power. By virtue of the rectification unit 11 and the energy storage unit 13 respectively outputting the DC rectified electric energy and the DC auxiliary electric energy to the drive unit 12 in the acceleration operation interval t11, the drive unit 12 can output the electric energy in the acceleration operation interval t11 The AC driving electric energy is enough to increase the rotation speed of the motor 20 to the target rotation speed S1 until the acceleration operation interval t11 ends.

After the acceleration operation interval t11 ends, in the constant speed operation interval t12 of the motor period T1, the drive unit 12 continues to operate in the first operation mode, and continues to receive the DC input power through the DC side connection terminal 121, The DC input power is converted into the AC driving power, and the AC driving power is output to the motor 20 through the AC side connection terminals 122 , so that the speed of the motor 20 can be maintained within the predetermined speed range.

On the other hand, in the constant speed operation interval t12, the control unit 14 For example, the remaining power of the energy storage unit 13 is continuously compared with a preset high power threshold and a low power threshold smaller than the high power threshold to determine whether to control the rectifier unit 11 to output the DC rectified electrical energy. Wherein, the control unit 14, for example, obtains the current remaining power of the energy storage unit 13 by using the coulometric method, but can also obtain the current remaining power of the energy storage unit 13 by detecting the terminal voltage of the energy storage unit 13 , and, the high battery threshold value and the low battery threshold value can be implemented as two battery state (State of charge) percentages respectively, and can be implemented as 75% and 25% respectively, but they are not regarded as limit.

More specifically, in the constant speed operation interval t12 of this embodiment, when the control unit 14 determines that the remaining power of the energy storage unit 13 is higher than the high power threshold, the control unit 14 controls the rectifier The unit 11 does not output the DC rectified electric energy to the drive unit 12 (that is, the first current _I1 is 0 ampere), so that the energy storage unit 13 continues to discharge the drive unit 12, and the energy storage unit 13 The energy storage percentage continues to decrease. In this case, the drive unit 12 only uses the DC auxiliary power as the DC input power to generate and output the AC drive power.

Then, until the control unit 14 determines that the remaining power of the energy storage unit 13 is lower than the low power threshold, the control unit 14 controls the rectification unit 11 to start outputting the DC rectified power to the drive unit 12, so that The energy storage unit 13 stops discharging. In this case, the drive unit 12 only uses the DC rectified power as the DC input power to generate the AC drive power until the constant speed operation interval t12 ends (corresponds to the end of the motor period T1).

It is supplemented that, since the average power consumed by the motor 20 in the constant speed operation interval t12 is much lower than the average power consumed in the acceleration operation interval t11, the rectification unit 11 and the energy storage unit 13 In the constant speed operation interval t12 , it is not necessary to output electric energy to the driving unit 12 at the same time, and it is sufficient to meet the power requirement of the motor 20 . In addition, in other implementations, the control unit 14 may also directly control the drive unit 12 to suspend the output of the DC rectified electric energy for a fixed period of time, for example, when entering the constant speed operation interval t12 from the acceleration operation interval t11, For example, the DC rectified power is not output until a specific time point in the constant speed operation interval t12 is reached, and the DC rectified power is output only when the specific time point is reached. Therefore, the control unit 14 The manner of controlling the driving unit 12 in the interval t12 is not limited by this embodiment.

After the constant speed operation interval t12 ends (that is, the motor period T1 ends), in the generator period T2, the control unit 14 controls the rectifier unit 11 not to output the DC rectified electric energy, and the drive unit 12 operates in The second working state is to continuously receive the AC regenerative power from the motor 20 through the AC side connection terminals 122, convert the AC regenerative power into the DC regenerative power, and connect the DC regenerative power through the DC side. The terminal 121 outputs to the energy storage unit 13, so that the energy storage unit 13 stores all the DC regenerative power received through the charge-discharge connection terminal 131 as DC auxiliary power during the generator period T2. Also, the energy storage unit The DC auxiliary energy stored by the unit 13 during the generator period T2 is used to be supplied to the drive unit 12 again in the acceleration operation interval t11 of the next working cycle T to drive the motor 20 .

It is worth noting that since the change of the rotational speed of the motor 20 is periodic in the application environment of this embodiment, the actual amount of the AC regenerative power generated by the motor 20 during each generator period T2 can be calculated by And/or measurement obtained, and has predictability, therefore, by properly planning the low battery threshold and the discharge time of the energy storage unit 13 in the motor period T1, the energy storage unit 13 can be used in the motor period T1 Pre-discharge to the energy storage percentage corresponding to the low power threshold, thereby ensuring that it has sufficient energy storage capacity during the generator period T2 to store all the AC regenerative power generated by the motor 20 as DC auxiliary power, In this way, this embodiment can avoid excessive enlargement of the total energy storage capacity of the energy storage unit 13 , and can achieve a high utilization rate of the total energy storage capacity of the energy storage unit 13 . On the other hand, by making the rectification unit 11 and the energy storage unit 13 respectively output the DC rectification power and the DC auxiliary power to the drive unit 12 during the acceleration operation interval t11 of the motor period T1, the present embodiment can When the speed of the motor 20 increases and the power consumption increases, the AC regenerative electric energy generated by the motor 20 during the generator period T2 of the previous working cycle T is used (that is, the energy storage unit 13 is used during the previous generator period T2 stored DC auxiliary electric energy) to drive the motor 20, thereby, this embodiment can not only effectively recover and reuse the AC regenerative electric energy generated when the motor 20 is decelerated, but also reduce the rectification unit 11 in the acceleration operation interval t11 The first current I ₁ that needs to be output in the rectifier unit 11, thereby reducing the current stress that the power components (such as various power switches) in the rectifier unit 11 need to bear, helps to reduce the cost of the rectifier unit 11. In addition, by reducing The first current I ₁ required to be output by the rectifier unit 11 in the acceleration operation interval t11 also helps to reduce the power loss of the rectification unit 11 in the acceleration operation interval t11 .

The above is an illustration of the first embodiment of the present invention.

The present invention also provides a second embodiment of the electric energy conversion and drive system 1 .

In the application of the second embodiment, different from the first embodiment, the rotational speed of the motor 20 is changed according to the user's manual operation of the working equipment, instead of periodically changing as shown in FIG. 3 , Therefore, there is no duty cycle T with a fixed time length. More specifically, in the application of the second embodiment, the rotation speed of the motor 20 does not have regularity and cannot be predicted. In the application of the example, it changes randomly. On the other hand, in the application of the second embodiment, as long as the rotation speed of the motor 20 is increased, it belongs to the acceleration operation section, regardless of the initial rotation speed S0 and the target rotation speed S1 .

In the second embodiment, the control unit 14 also detects through the charging and discharging connection terminal 131 of the energy storage unit 13, the DC output connection terminal 112 of the rectification unit 11, or the DC side connection terminal 121 of the drive unit 12. The variation of the voltage value of the DC rectified voltage V _{DC_REC} .

Specifically, in the case that the rectification unit 11 does not output the DC rectified electric energy (that is, the first current _I1 is 0 ampere), when the control unit 14 judges that the voltage value of the DC rectified voltage V _{DC_REC} is within a period When the drop exceeds a voltage change threshold value within a predetermined period of time (equivalent to the drop slope of the DC rectified voltage V _{DC_REC} exceeding a drop slope threshold value), it means that the drive unit 12 is operating in the first working state and the DC input The demand for electric energy increases rapidly (that is, the rotation speed of the motor 20 is increasing rapidly and the power consumption thereof increases rapidly), which causes the DC rectified voltage V _{DC_REC} to decrease rapidly. In this case, the control unit 14 controls the rectification unit 11 to start outputting the DC rectification power, so that the drive unit 12 can simultaneously receive enough DC input power from the rectification unit 11 and the energy storage unit 13, and output Sufficient AC drive power to drive the motor 20 . Wherein, the predetermined time length and the voltage change threshold can be freely set and adjusted according to the power characteristics of the motor 20 during accelerated operation, so there is no special limitation in this embodiment.

On the other hand, when the rectification unit 11 is outputting the DC rectified power (that is, the first current _I1 is greater than 0 ampere), when the control unit 14 judges that the voltage value of the DC rectification voltage V _{DC_REC} exceeds a high When the rated DC voltage is at the voltage threshold, it means that the drive unit 12 is operating in the second working state and outputting the DC regenerative power through the DC side connection terminal 121 (that is, it means that the motor 20 is generating AC regenerative power ), which causes the voltage of the DC regenerative voltage V _{DC_GEN} (shown in FIG. 2 ) to rise, and jointly causes the voltage value of the DC rectified voltage V _{DC_REC} (shown in FIG. 2 ) to rise. In this case, the control unit 14 controls the rectification unit 11 to stop outputting the DC rectified power, so that the energy storage unit 13 can receive the DC regenerative power outputted by the driving unit 12 and store it as auxiliary DC power.

In this way, even if the rotation speed of the motor 20 in the second embodiment is unpredictable, the electric energy conversion and driving system 1 of the second embodiment can still utilize the energy storage unit 13 when the motor 20 is in the generator state The AC regenerative power generated by the motor 20 is stored as DC auxiliary power, and then the motor 20 is driven by the DC auxiliary power stored in the energy storage unit 13 when the motor 20 is in the motor state and the speed increases.

The above is an illustration of the second embodiment of the present invention.

Referring to FIG. 4 , the present invention also provides a third embodiment of the electric energy conversion and drive system 1 .

In the third embodiment, besides including the rectification unit 11, the drive unit 12, the energy storage unit 13 and the control unit 14, the electric energy conversion and drive system 1 further includes a and the bidirectional voltage conversion unit 15 between the energy storage unit 13 and used as a switch unit. Moreover, different from the first embodiment, the control unit 14 is electrically connected to the bidirectional voltage converting unit 15 and the driving unit 12 in the third embodiment, but not electrically connected to the rectifying unit 11 .

The bidirectional voltage conversion unit 15 can be implemented, for example, as a bidirectional buck-boost Bidirectional buck-boost converter, or other existing topologies that can realize bidirectional DC voltage conversion. Wherein, the bidirectional voltage conversion unit 15 includes a first terminal electrically connected to the DC side connection terminal 121 of the driving unit 12 , and a second terminal electrically connected to the charging and discharging connection terminal 131 of the energy storage unit 13 . Moreover, in this embodiment, the first terminal is used as a high-voltage side connection terminal 151 included in the bidirectional voltage conversion unit 15, and the second terminal is used as a low-voltage side connection terminal included in the bidirectional voltage conversion unit 15. Connection terminal 152 .

The bidirectional voltage conversion unit 15 can be switched between a boost working state, a buck working state and an off state under the control of the control unit 14 .

Specifically, when the bidirectional voltage conversion unit 15 operates in the boost working state, the high voltage side connection terminal 151 and the low voltage side connection terminal 152 are electrically connected to each other, in this case, the bidirectional voltage conversion unit 15 Electric energy is allowed to be transmitted from the low-voltage side connection end 152 to the high-voltage side connection end 151 . Moreover, when the bidirectional voltage conversion unit 15 operates in the boosting working state, the bidirectional voltage conversion unit 15 will perform a boosting process on the electric energy received through the low-voltage side connection terminal 152, and then convert the boosted The processed power is output through the high-voltage side connection terminal 151 , so that the voltage output by the bidirectional voltage conversion unit 15 through the high-voltage side connection terminal 151 is higher than the voltage received by the low-voltage side connection terminal 152 . For example, the bidirectional voltage conversion unit 15 can boost the DC voltage received by the low-voltage side connection terminal 152 to 311 volts and then pass through the high-voltage side connection terminal according to the pulse width modulation control of the control unit 14 151 output, but not limited thereto.

On the other hand, when the bidirectional voltage conversion unit 15 operates in the step-down working state, the high voltage side connection terminal 151 and the low voltage side connection terminal 152 are electrically connected to each other, in this case, the bidirectional voltage conversion unit 15 Electric energy is allowed to be transmitted from the high-voltage side connection end 151 to the low-voltage side connection end 152 . Moreover, when the bidirectional voltage conversion unit 15 operates in the step-down working state, the bidirectional voltage conversion unit 15 will perform a step-down process on the electric energy received through the high-voltage side connection terminal 151, and then convert the power received through the step-down The processed power is output through the low-voltage side connection 152 , so that the voltage output by the bidirectional voltage conversion unit 15 through the low-voltage side connection 152 is lower than the voltage received by the high-voltage side connection 151 . For example, the bidirectional voltage conversion unit 15 can step down the DC voltage received by the high-voltage side connection terminal 151 to 100 volts through the low-voltage side connection terminal, for example, according to the pulse width modulation control of the control unit 14 152 output, but not limited thereto.

On the other hand, when the bidirectional voltage conversion unit 15 operates in the off state, the high-voltage side connection terminal 151 and the low-voltage side connection terminal 152 are not electrically connected (that is, they are not conductive to each other). In other words, when the bidirectional voltage conversion unit 15 operates in the off state, the bidirectional voltage conversion unit 15 does not allow power transmission between the high voltage side connection terminal 151 and the low voltage side connection terminal 152 .

In the application environment of the third embodiment, the operation of the motor 20 is the same as that described in the first embodiment. In other words, the rotation speed of the motor 20 in the third embodiment The speed changes as shown in Figure 3, for example, and will not be repeated here.

Referring to FIG. 3 to FIG. 5 at the same time, the operation mode of the electric energy conversion and drive system 1 in the third embodiment in the working cycle T of FIG. 3 will be described below. Likewise, it is assumed here that the energy storage unit 13 has pre-stored DC auxiliary power when the working cycle T starts.

In the third embodiment, the same as the first embodiment, the drive unit 12 is also between the first working state and the second working state according to the respective time lengths of the motor period T1 and the generator period T2. Periodically switch repeatedly, that is, operate in the first working state in the motor period T1, and operate in the second working state in the generator period T2.

First, in the acceleration operation interval t11 of the motor period T1, the rectification unit 11 receives the AC input power from the AC power source 10 through the two AC input terminals 111, converts the AC input power into the DC rectified power, and The DC rectified power is output to the driving unit 12 through the DC output terminal 112 . On the other hand, the control unit 14 controls the bidirectional voltage conversion unit 15 to operate in the boost working state. Therefore, in the acceleration operation interval t11, when the bidirectional voltage conversion unit 15 receives a signal from the low-voltage side connection terminal 152 When the DC auxiliary power of the energy storage unit 13 is used, the bidirectional voltage conversion unit 15 is controlled by the control unit 14 to perform a step-up process on the DC auxiliary power, and then passes the boosted DC auxiliary power through the The high-voltage side connection terminal 151 is output to the driving unit 12 , so that a fourth current I ₄ flowing out from the high-voltage side connection terminal 151 is formed. In other words, in the acceleration operation interval t11 , the DC auxiliary power stored in the energy storage unit 13 is at least partially provided to the driving unit 12 via the bidirectional voltage conversion unit 15 . On the other hand, the drive unit 12 continues to operate in the first working state in the acceleration operation interval t11 of the motor period T1, whereby the drive unit 12 continues to receive the DC input power through the DC side connection terminal 121, and will The DC input power is converted into the AC driving power, and the AC driving power is output to the motor 20 through the AC side connection terminals 122, wherein, as shown in FIG. The DC input voltage V _{DC_IN} of the input power is converted into the AC driving voltage V _{AC_OUT} corresponding to the AC driving power, so as to convert the DC input power into the AC driving power. Similar to the first embodiment, the drive unit 12 uses the DC rectified power and the DC auxiliary power together as the DC input power in the acceleration operation interval t11 to generate and output enough to increase the speed of the motor 20 to the The AC driving electric energy of the target speed S1 is used until the end of the acceleration operation interval t11, at this time, the magnitude of the third current _I3 is the sum of the first current _I1 and the fourth current _I4 .

After the acceleration operation interval t11 ends, in the constant speed operation interval t12 of the motor period T1, the drive unit 12 continues to operate in the first operation mode to continue to receive the DC input power through the DC side connection terminal 121, Converting the DC input power into the AC driving power, and outputting the AC driving power to the motor 20 through the AC side connection terminals 122, so that the rotation speed of the motor 20 can be maintained at the within the predetermined speed range.

On the other hand, in the constant speed operation interval t12, the control unit 14, for example, continuously compares the remaining power of the energy storage unit 13 with the preset high power threshold and the low power threshold to determine Whether to control the bidirectional voltage conversion unit 15 to continue to operate in the boost working state. More specifically, in the constant speed operation interval t12, when the remaining power of the energy storage unit 13 is higher than the high power threshold, the control unit 14 controls the bidirectional voltage conversion unit 15 to continue to operate at the rising power level. Voltage working state, so that the DC auxiliary power continues to be provided from the energy storage unit 13 to the drive unit 12 through the bidirectional voltage conversion unit 15, at this time, the current magnitude of the third current _I3 is still the first current The sum of I ₁ and the fourth current I ₄ . Then, until the remaining power of the energy storage unit 13 drops below the low power threshold, the control unit 14 controls the bidirectional voltage conversion unit 15 to switch to the off state, so that the energy storage unit 13 stops outputting the DC Auxiliary power, and make the drive unit 12 only use the DC rectified power output by the rectifier unit 11 as the DC input power to generate the AC drive power until the constant speed operation interval t12 ends (equivalent to the end of the motor period T1) , at this moment, the fourth current I ₄ is substantially 0 ampere, and the magnitude of the third current I ₃ is equal to the first current I ₁ .

It is added that, in other implementations, the control unit 14 may also control the bidirectional voltage conversion unit 15 to continue to operate in the boosting operation when entering the constant speed operation interval t12 from the acceleration operation interval t11, for example. state, and at this constant speed When the specific time point of the operation interval t12 arrives, the bidirectional voltage conversion unit 15 is controlled to switch to the off state. Alternatively, the control unit 14 may also, for example, control the bidirectional voltage conversion unit 15 to operate in the boosting working state before the end of the constant speed operation interval t12. Therefore, the control unit 14 controls in the constant speed operation interval t12. The operation mode of the bidirectional voltage conversion unit 15 is not limited by this embodiment.

After the constant speed operation interval t12 ends (that is, the motor period T1 ends), during the generator period T2, the drive unit 12 operates in the second working state, whereby the drive unit 12 continues to pass through the AC The side connection terminal 122 receives the AC regenerative power from the motor 20, converts the AC regenerative power into the DC regenerative power, and outputs the DC regenerative power to the bidirectional voltage conversion unit 15 through the DC side connection 121, wherein , as shown in FIG. 5 , the drive unit 12 converts the AC regenerative power into the DC by converting the AC regenerative voltage V _{AC_GEN} corresponding to the AC regenerative power into the DC regenerative voltage V _{DC_GEN} corresponding to the DC regenerative power Regenerative power. On the other hand, when the generator period T2 starts, the control unit 14 controls the bidirectional voltage conversion unit 15 to switch to the step-down working state, so that a regenerative current I _GEN flows from the DC side connection terminal 121 of the drive unit 12 flow into the high-voltage side connection terminal 151 of the bidirectional voltage conversion unit 15, so during the generator period T2, when the bidirectional voltage conversion unit 15 receives the DC regenerative power from the drive unit 12 through the high-voltage side connection terminal 151 , the bidirectional voltage conversion unit 15 is controlled by the control unit 14 to perform the step-down process on the DC regenerative power, and then outputs the DC regenerative power that has undergone the step-down process to the energy storage through the low-voltage side connection terminal 152 unit 13, so that the energy storage unit 13 stores all the DC regenerative power received through the bidirectional voltage conversion unit 15 during the generator period T2 as DC auxiliary power. Moreover, the DC auxiliary energy stored by the energy storage unit 13 during the generator period T2 is used to be provided to the driving unit 12 again in the acceleration operation interval t11 of the next working cycle T to drive the motor 20 .

The electric energy conversion and drive system 1 of the third embodiment can also use the regenerative electric energy generated by the motor 20 in the previous working cycle T to drive the motor 20 when the speed of the motor 20 increases and the power consumption increases, thereby reducing The current stress that the power components in the driving unit 12 need to bear in the acceleration operation interval t11 can also reduce the power loss of the rectification unit 11 in the acceleration operation interval t11, and realize the overall performance of the energy storage unit 13. High utilization of energy storage capacity. In addition, the bidirectional voltage conversion unit 15 in the third embodiment also helps to reduce the voltage stress on the energy storage unit 13, so that the energy storage unit 13 can be realized with a supercapacitor with a lower withstand voltage specification, so This helps to reduce the cost of the energy storage unit 13 .

The above is an illustration of the third embodiment of the present invention.

The present invention also provides a fourth embodiment of the electric energy conversion and drive system 1 .

In the application of the fourth embodiment, as in the application of the second embodiment, the change of the rotational speed of the motor 20 is irregular and cannot be predicted.

In the fourth embodiment, the control unit 14 detects the change of the current value of the first current I ₁ , for example, through the DC output connection terminal 112 of the rectification unit 11 .

Specifically, when the bidirectional voltage conversion unit 15 is operating in the step-down working state or in the off state, when the control unit 14 determines that the current value of the first current _I1 rises more than When a current change threshold value (equivalent to the rising slope of the first current _I1 exceeds a rising slope threshold value), it means that the driving unit 12 is operating in the first working state and the demand for the DC input power increases rapidly ( That is to say, the rotational speed of the motor 20 is increasing rapidly, resulting in a rapid increase in its power consumption). In this case, the control unit 14 controls the bidirectional voltage conversion unit 15 to switch to the boost working state, so as to facilitate the energy storage unit 13 to discharge the driving unit 12 through the bidirectional voltage conversion unit 15, so that the storage unit The stored DC regenerative power can be provided to the drive unit 12 through the bidirectional voltage conversion unit 15, whereby the drive unit 12 can simultaneously receive sufficient DC input from the rectification unit 11 and the bidirectional voltage conversion unit 15 Electric energy, and output enough AC driving electric energy to drive the motor 20. Wherein, the predetermined time length and the current change threshold value can be freely set and adjusted according to the power characteristic of the motor 20 during acceleration operation, so this embodiment does not make any special limitation thereon.

On the other hand, when the bidirectional voltage conversion unit 15 is operating in the boost working state or the off state, when the control unit 14 determines that the voltage value of the DC rectified voltage V _{DC_REC} exceeds a value higher than the rated DC voltage value of the voltage threshold, it means that the drive unit 12 is operating in the second working state and outputting the DC regenerative power through the DC side connection terminal 121 (that is, it means that the motor 20 is generating AC regenerative power), resulting in the The voltage value of the DC rectified voltage V _{DC_REC} rises. In this case, the control unit 14 controls the bidirectional voltage conversion unit 15 to switch to the step-down working state, so that the energy storage unit 13 receives the DC regenerative power outputted by the drive unit 12 through the bidirectional voltage conversion unit 15, And store it all as auxiliary DC power.

In this way, even if the change of the rotational speed of the motor 20 in the fourth embodiment is unpredictable, the electric energy conversion and driving system 1 of the fourth embodiment can still utilize the energy storage unit when the motor 20 is in the generator state 13 Store the AC regenerative power generated by the motor 20 as DC auxiliary power through the bidirectional voltage conversion unit 15, and then use the DC auxiliary power stored in the energy storage unit 13 when the motor 20 is in the motor state and the speed increases. Drive the motor 20 to operate.

It is supplemented that, in a similar implementation of the fourth embodiment, when the bidirectional voltage conversion unit 15 operates in the step-down working state or in the off state, the control unit 14 can also, for example, through the drive The DC side connection terminal 121 of the unit 12 detects the change of the current value of the third current _I3 , and determines whether to control the bidirectional voltage conversion unit 15 to switch to the step-up operation according to the slope change of the third current _I3 . state.

The above is an illustration of the fourth embodiment of the present invention.

To sum up, the electric energy conversion and driving system 1 can use the energy storage unit 13 to store the AC regenerative electric energy generated when the motor 20 is in the generator state as DC auxiliary electric energy, and then when the motor 20 is in the motor state And when the rotation speed increases, the energy storage unit 13 and the rectification unit 11 simultaneously output DC auxiliary power and DC rectification power to drive the motor, thereby, the power conversion and drive system 1 can not only effectively utilize the power generated by the motor 20 The AC regenerative electric energy can reduce the overall power consumption of the electric energy conversion and drive system 1, and can also reduce the current stress that the rectifier unit 11 needs to bear when the speed of the motor 20 rises and the power loss of the rectifier unit 11, so as to achieve more Good energy-saving benefit, so really can reach the purpose of the present invention.

But what is described above is only an embodiment of the present invention, and should not limit the scope of the present invention. All simple equivalent changes and modifications made according to the patent scope of the present invention and the content of the patent specification are still within the scope of the present invention. Within the scope covered by the patent of the present invention.

1: Electric energy conversion and drive system

11: rectifier unit

111: AC input connection terminal

112: DC output connection terminal

12: Drive unit

121: DC side connection terminal

122: AC side connection terminal

13: Energy storage unit

131: charging and discharging connection terminal

14: Control unit

10: AC power

20: motor

V _{AC_IN} : AC input voltage

V _{DC_REC} : DC rectified voltage

V _{DC_IN} : DC input voltage

V _{AC_OUT} : AC drive voltage

I ₁ : first current

I ₂ : the second current

I ₃ : the third current

Claims (9)

An electrical energy conversion and drive system adapted to be electrically connected between an AC power source and a motor operable in a motor state that operates by consuming electric energy, and a generator state that generates electric energy by rotating, The two periods during which the motor operates in the motor state and the generator state are respectively referred to as a motor period and a generator period, and the period during which the motor operates in the motor state and the speed rises is included as a period in the motor During the acceleration operation interval; the electric energy conversion and drive system includes: a rectifier unit, suitable for electrical connection with the AC power supply; a drive unit, electrically connected with the rectifier unit, and suitable for electrical connection with the motor; an energy storage unit , electrically connected to the drive unit, and used to store the electric energy generated by the motor during the generator period as a DC auxiliary power, and discharge it at least during the acceleration operation interval of the motor, so that the DC auxiliary power is Provided to the drive unit; and a control unit electrically connected to the rectifier unit and the drive unit, the control unit is used to: control the rectifier unit to use the electric energy provided by the AC power supply to generate And output a DC rectified power to the drive unit, and control the drive unit to convert a DC input power into an AC drive power and output the AC drive power to the motor, wherein the DC input power is simultaneously within the acceleration operation range Including the DC rectified power and the DC auxiliary power. The electric energy conversion and drive system as described in Claim 1, wherein the acceleration The operation interval is the period during which the rotation speed of the motor rises from an initial rotation speed to a target rotation speed during the motor period, and after the acceleration operation interval, the rotation speed of the motor is maintained within a predetermined rotation speed range covering the target rotation speed The period is regarded as a constant speed operation interval included in the motor period; the control unit is also used for: in the constant speed operation interval of the motor period, when the remaining power of the energy storage unit is higher than a high power threshold value In this case, the rectification unit is controlled not to output the DC rectified electric energy to the drive unit, so that the energy storage unit continues to discharge during the constant speed operation interval of the motor, and the drive unit only uses the DC auxiliary electric energy as the DC input electric energy to generate the AC driving electric energy; and during the constant speed operation interval of the electric motor, when the remaining power of the energy storage unit is lower than a low power threshold less than the high power threshold, controlling the The rectifying unit outputs the DC rectified power to the driving unit, so that the energy storage unit stops discharging, and the driving unit only uses the DC rectified power as the DC input power to generate the AC driving power. The electric energy conversion and driving system as described in claim 1, wherein, the electric energy generated when the motor operates in the generator state is used as an AC regenerative electric energy; the control unit is also used for: during the period of the generator, control The drive unit receives the AC regenerative power, converts the AC regenerative power into a DC regenerative power, and outputs the DC regenerative power to the energy storage unit for the energy storage unit to store the DC regenerative power as the DC auxiliary electrical energy. The electric energy conversion and drive system as described in claim 3, wherein the motor is periodically switched between the motor state and the generator state; the drive unit converts the DC input electric energy into the AC drive electric energy and outputs The operating state of the motor is regarded as a first operating state of the driving unit, and the operating state of the driving unit converting the AC regenerative electric energy into the DC regenerative electric energy output to the energy storage unit is regarded as a second operating state of the driving unit working state, and the control unit controls the drive unit to switch periodically and repeatedly between the first working state and the second working state according to the respective time lengths of the motor period and the generator period. An electrical energy conversion and drive system adapted to be electrically connected between an AC power source and a motor operable in a motor state that operates by consuming electric energy, and a generator state that generates electric energy by rotating, The two periods during which the motor operates in the motor state and the generator state are respectively referred to as a motor period and a generator period, and the period during which the motor operates in the motor state and the speed rises is included as a period in the motor During the acceleration operation interval; the electric energy conversion and drive system includes: a rectifier unit, suitable for electrical connection with the AC power supply, and for generating and outputting a DC rectified electric energy by using the electric energy provided by the AC power supply; a drive unit, Electrically connected to the rectifier unit, and suitable for electrical connection with the motor; a switch unit, including a first end electrically connected to the drive unit, and a second end; an energy storage unit, electrically connected to the second end of the switch unit two-terminal, and for storing the electrical energy generated by the motor during the generator period as a DC auxiliary electrical energy, and discharging it at least during the acceleration operation period of the motor, so that the DC auxiliary electrical energy is provided to the drive unit through the switch unit; and a control unit, electrically connected to the switch unit and the drive unit, the control unit is used to: control the first end and the second end of the switch unit to be electrically connected to each other during the acceleration operation interval of the motor, so that The DC auxiliary power is provided from the energy storage unit to the drive unit through the switch unit, and the drive unit is controlled to convert a DC input power into an AC drive power and output the AC drive power to the motor, wherein the DC The input electric energy includes the DC rectification electric energy and the DC auxiliary electric energy at the same time in the acceleration operation range. The electric energy conversion and drive system according to claim 5, wherein the acceleration operation interval is a period during which the motor speed increases from an initial rotation speed to a target rotation speed during the motor period, and after the acceleration operation interval, The period during which the rotational speed of the motor is maintained within a predetermined rotational speed range covering the target rotational speed is regarded as a constant speed operation interval included in the period of the electric motor; the control unit is also used for: in the constant speed operation interval of the electric motor , when the remaining power of the energy storage unit is higher than a high power threshold value, the first end and the second end of the switch unit are controlled to continue to be electrically connected to each other, so that the DC auxiliary power continues to be transferred from the energy storage unit is supplied to the drive unit through the switch unit; and during the constant speed operation interval of the motor, in the energy storage unit When the remaining power is lower than a low power threshold less than the high power threshold, control the first end and the second end of the switch unit to be electrically disconnected from each other, so that the energy storage unit stops outputting the DC auxiliary power. electrical energy. The electric energy conversion and driving system as described in claim 6, wherein: the switch unit is a bidirectional voltage conversion unit, the first terminal is a high-voltage side connection terminal of the bidirectional voltage conversion unit, and the second terminal is the bidirectional voltage conversion unit. A low-voltage side connection terminal of the voltage conversion unit; when the bidirectional voltage conversion unit operates in a boost working state, the first terminal and the second terminal of the switch unit are electrically connected to each other, and the bidirectional voltage conversion unit passes through the The low-voltage side connection end receives the DC auxiliary power from the energy storage unit, performs a step-up process on the DC auxiliary power, and outputs the boosted DC auxiliary power to the drive unit through the high-voltage side connection end ; and in the period of acceleration operation of the motor, and in the period of constant speed operation of the motor and the remaining power of the energy storage unit is higher than a high power threshold, the control unit is to control the bidirectional voltage The conversion unit operates in the boost working state. The electric energy conversion and drive system as described in claim 5, wherein, the electric energy generated when the motor operates in the generator state is used as an AC regenerative electric energy; the control unit is also used for: during the generator period, control The first end and the second end of the switch unit are electrically connected to each other, and the drive unit is controlled to receive the AC regenerative power, convert the AC regenerative power into a DC regenerative power, and pass the DC regenerative power through the switch unit output to the energy storage unit for the energy storage unit to store the DC regenerative energy as The DC auxiliary power. The electric energy conversion and drive system according to claim 8, wherein: the switch unit is a bidirectional voltage conversion unit, the first terminal is a high-voltage side connection terminal of the bidirectional voltage conversion unit, and the second terminal is the bidirectional voltage conversion unit. A low-voltage side connection end of the voltage conversion unit; when the bidirectional voltage conversion unit operates in a step-down working state, the first end and the second end of the switch unit are electrically connected to each other, and the bidirectional voltage conversion unit passes through the The high-voltage side connection end receives the DC regenerative power from the drive unit, performs a step-down process on the DC regenerative power, and outputs the DC regenerative power after the step-down processing to the energy storage unit through the low-voltage side connection end ; and during the period of the generator, the control unit controls the bidirectional voltage conversion unit to operate in the step-down working state.

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