TW202341637A - Electric energy conversion and drive system can effectively utilize the regenerative electric energy generated by the motor - Google Patents

Abstract

An electric energy conversion and drive system is suitable for an AC power supply and a motor. The motor is operable in a motor state for operating by consuming electric energy, and a generator state for generating electric energy by rotating. The electric energy conversion and drive system includes a rectifier 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 to the driving unit. The energy storage unit is configured to store the electric energy generated when the motor is in the generator state, and to output the electric energy to the driving unit at the same time as the rectifier unit when the motor is in the motor state and the rotating speed increases, so that the rectifier unit outputs AC driving electric energy to the motor according to the electric energy provided by the energy storage unit and the rectifier unit.

Description

Electric energy conversion and drive system

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

In the existing technology, some driving systems used to drive motors are equipped with energy storage components (such as capacitors) to store the regenerated electrical energy generated by the motor during deceleration. How to properly utilize the stored regenerative electrical energy to achieve better energy saving? Effectiveness has become an issue worthy of study.

Therefore, an object of the present invention is to provide an electric energy conversion and driving system that can effectively utilize the regenerated electric energy generated by the motor.

The electric energy conversion and driving system of the present invention is suitable for electrical connection between an AC power source and a motor. The motor can operate in a motor state that consumes electric energy and a generator state that generates electric energy by rotating. The two periods in which the motor operates in the motor state and the generator state are regarded as a motor period and a generator period respectively, and the period in which the motor operates in the motor state and the rotational speed increases is regarded as a period included in the motor. acceleration operation range during this period. The electric energy conversion and drive system includes: a rectifier unit, a drive unit, an energy storage unit, and a control unit electrically connected to the rectifier unit and the drive unit. The rectifier unit is adapted to be electrically connected to the AC power supply. The drive unit is electrically connected to the rectifier unit and is suitable for electrical connection with the motor. The energy storage unit is electrically connected to the driving unit, and is used to store the electric energy generated by the motor during the generator period as DC auxiliary electric energy, and to discharge it at least in the acceleration operation interval of the motor period, so that the DC Auxiliary electrical energy is provided to the drive unit. The control unit is used to: during the acceleration operation period of the motor, control the rectifier unit to use the electric energy provided by the AC power supply to generate and output DC rectified electric energy to the drive unit, and control the drive unit to input DC electric energy. Convert into an AC driving power and output the AC driving power to the motor. Wherein, the DC input power includes both the DC rectified power and the DC auxiliary power within the acceleration operation interval.

In some implementations of the electric energy conversion and driving system of the present invention, the acceleration operation interval is a 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 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 to: within the constant-speed operation interval of the electric motor period , when the remaining power of the energy storage unit is higher than a high power threshold, the rectifier unit is controlled not to output the DC rectified power to the drive unit, so that the energy storage unit operates at a constant speed during the motor period. Continue to discharge within the period, and make the drive unit only use the DC auxiliary power as the DC input power to generate the AC drive power; during the constant speed operation range of the motor, the remaining power of the energy storage unit is less than less than In the case of a low battery threshold between a high battery threshold and a low battery threshold, the rectifier unit is controlled to output the DC rectified electric energy to the driving unit, so that the energy storage unit stops discharging, and the driving unit only uses the DC rectified electric energy as the DC input power is used to generate the AC driving power.

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

In some implementations of the electric energy conversion and drive system of the present invention, the motor periodically switches 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 converts the AC regenerated electrical energy into the DC regenerated electrical energy and outputs it to the energy storage unit is regarded as a second operating state of the driving unit. working state, and the control unit controls the driving unit to periodically and repeatedly switch 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 driving system.

Another electric energy conversion and driving system of the present invention is suitable for electrical connection between an AC power supply and a motor. The motor can operate in a state of a motor that operates by consuming electric energy, and a motor that generates electric energy by rotating. Generator status. The two periods in which the motor operates in the motor state and the generator state are regarded as a motor period and a generator period respectively, and the period in which the motor operates in the motor state and the rotational speed increases is regarded as a period included in the motor. acceleration operation range during this period. The electric energy conversion and driving system includes a rectifier unit, a driving unit, a switching unit, an energy storage unit, and a control unit electrically connected to the switching unit and the driving unit. The rectifier unit is adapted to be electrically connected to the AC power source, and is used to generate and output DC rectified power using the power provided by the AC power source. The drive unit is electrically connected to the rectifier unit and is suitable for electrical connection with the motor. The switch unit includes a first end electrically connected to the driving unit, and a second end. The energy storage unit is electrically connected to the second end of the switch unit, and is used to store the electric energy generated by the motor during the generator period as DC auxiliary electric energy, and to discharge it at least during the acceleration operation interval of the motor period. , so that the DC auxiliary power is provided to the driving unit through the switch 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 so that the DC auxiliary power is provided from the energy storage unit through the switch unit during the acceleration operation period of the motor. to the driving unit, and controlling the driving unit to convert DC input power into AC driving power and output the AC driving power to the motor. Wherein, the DC input power includes both the DC rectified power and the DC auxiliary power within the acceleration operation interval.

In some implementations of the electric energy conversion and driving system of the present invention, the acceleration operation interval is a 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 during the acceleration After the operation interval, the period during which the rotation speed of the motor is maintained within a predetermined rotation speed range covering the target rotation speed is regarded as a constant speed operation interval included in the motor period. The control unit is also used to control the first end and the second end 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 range of the motor. The terminals continue to be electrically connected to each other, so that the DC auxiliary power continues to be provided from the energy storage unit to the driving unit through the switch unit; during the constant speed operation range of the motor, the remaining power of the energy storage unit is less than When the low power threshold is less than the high power threshold, the first end and the second end of the switch unit are controlled to be non-electrically connected to each other, so that the energy storage unit stops outputting the DC auxiliary power.

In some implementations of the 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 terminal is a low-voltage side connection terminal of the bidirectional voltage conversion unit. When the bidirectional voltage conversion unit operates in a boost operating 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 data from the energy storage unit through the low-voltage side connection terminal. The DC auxiliary power is boosted, and the boosted DC auxiliary power is output to the drive unit through the high-voltage side connection terminal. The control unit controls the bidirectional voltage conversion unit when the electric motor is in the acceleration operation range and the electric motor is in the constant speed operation period and the remaining power of the energy storage unit is higher than a high power threshold. Operate in this boosted working state.

In some implementations 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 AC regenerative electric energy. The control unit is also used to: during the generator period, control the first end and the second end of the switch unit to be electrically connected to each other, and control the driving unit to receive the AC regenerated electrical energy and convert the AC regenerated electrical energy into DC regenerated electric energy is output to the energy storage unit through the switch unit, so that the energy storage unit stores the DC regenerated electric energy as the DC auxiliary electric energy.

In some implementations of the 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 terminal is a low-voltage side connection terminal of the bidirectional voltage conversion unit. When the bidirectional voltage conversion unit operates in a buck operating state, the first end and the second end of the switch unit are electrically connected to each other, and the bidirectional voltage conversion unit receives the signal from the driving unit through the high-voltage side connection terminal. The DC regenerated electric energy is subjected to a voltage reduction process, and the DC regenerated electric energy that has undergone the voltage reduction process 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 buck operating state.

The effect of the present invention is that the electric energy conversion and driving system can use the energy storage unit to store the AC regenerated electric energy generated when the motor is in the generator state as DC auxiliary electric energy, and then when the motor is in the motor state and the rotation speed increases The energy storage unit and the rectifier unit simultaneously output DC auxiliary power and DC rectifier power to drive the motor. In this way, 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 needs to withstand when the motor speed increases and the power loss of the rectifier unit to achieve better energy saving benefits.

Before the present invention is described in detail, it should be noted that in the following description, similar elements are represented by the same numbers. If not specifically defined, the "electrical connection" described in this patent specification generally refers to the "wired electrical connection" achieved by connecting multiple electronic devices/devices/components to each other through conductive materials, as well as through wireless communication technology. "Radio connection" for one/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 multiple electronic devices/devices/components being directly connected to each other, as well as the "direct electrical connection" between multiple electronic devices/devices/components. They are also indirectly connected to each other through other electronic equipment/devices/components to form an "indirect electrical connection".

Referring to FIG. 1 , a first embodiment of the electric energy conversion and driving system 1 of the present invention is suitable for electrical connection between an AC power supply 10 and a motor 20 , and the electric energy conversion and driving system 1 is suitable for utilizing the AC power supply 10 The provided electric energy drives the motor 20 to operate.

For convenience of description, the electric energy provided by the AC power supply 10 is used as an AC input electric energy in the application of this embodiment. To be more specific, in the application of this embodiment, the AC power supply 10 can be, for example, a commercial power supply that can provide an effective voltage of 220 volts, and the AC input power provided by the AC power supply 10 can be, for example, a single-phase sine wave AC power. . However, in different applications of this embodiment, the AC power supply 10 can also be, for example, a commercial power supply that can provide an effective voltage of 110 volts, or an AC power supply equipment, and the AC input power can also be, for example, a polyphase sine wave. Alternating current (such as three-phase sine wave alternating current) is 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 equipment (not shown), and the working equipment can be, for example, a stamping equipment, but this is not intended to be used as an example. limit. For example, the motor 20 may be used to drive a slider (not shown) included in the stamping equipment to reciprocate up and down to implement the stamping operation. Moreover, the motor 20 can be operated in a motor state that rotates by consuming electrical energy, and a generator state that is driven by inertia or other non-electric external forces to rotate and thereby generate regenerative power. For the convenience of description, the regenerative electric energy generated when the motor 20 is in the generator state is regarded as an AC regenerative electric energy in the application of this embodiment. Moreover, it should be added that in other application environments of this embodiment, the motor 20 may also be applied to other types of working equipment, such as lathes, drilling equipment, cutting equipment, lifting equipment, etc., instead of This is limited to the stamping equipment exemplified above.

The electric energy conversion and drive system 1 includes a rectifier unit 11 adapted to be electrically connected to the AC power supply 10, a drive unit 12 adapted to be electrically connected to the motor 20 and also electrically connected to the rectifier unit 11, and a drive unit 12 electrically connected to the drive unit 11. The unit 12 is an energy storage unit 13 capable of storing electrical energy, and a control unit 14 electrically connected to the rectifier unit 11 and the driving unit 12 .

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

In more detail, the control unit 14 can, for example, control the rectification unit 11 to convert the power from the AC power supply 10 by outputting a plurality of trigger voltage signals or trigger current signals to the active power switching elements of the rectifier unit 11 . 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} . The power of the DC rectified electric energy output by the rectifier unit 11 is used as the 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 I ₁ flowing out from the DC output connection terminal 112. In other words, the rectified output power changes as the magnitude of the first current I ₁ changes. .

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

In this embodiment, the driving unit 12 is a bidirectional inverter (also called an Inverter) that can realize bidirectional voltage AC to DC conversion, and the driving unit 12 includes, for example, a DC output connection end electrically connected to the rectifying unit 11 112 and the DC side connection terminal 121 of the energy storage unit 13, three AC side connection terminals 122 suitable for electrical connection to the motor 20, and one electrically connected to the DC side connection terminal 121 and the AC side connection terminals 122. three-phase rectifier bridge circuit (not shown). It should be added that the three-phase rectifier bridge circuit is, for example, implemented with 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 terminals 122 may be two, but is not limited to this embodiment.

The driving unit 12 can switch between a first working state and a second working state. The first working state is used to convert the DC power received through the DC side connection end 121 into AC power and then transmit it through The AC side connection terminals 122 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 it through the DC side connection terminal 121.

In more detail, when the driving unit 12 operates in the first working state, the driving unit 12 receives a DC from at least one of the rectifying unit 11 and the energy storage unit 13 through the DC side connection terminal 121 . Input electric energy, and be controlled by the control unit 14 to convert the DC input electric energy into an AC driving electric energy, and output the AC driving electric energy to the motor 20 through the AC side connection terminals 122, thereby driving the motor 20 Operate in this motor state. More specifically, as shown in FIG. 1 , when the driving unit 12 operates in the first working state, the control unit 14 uses pulse-width modulation (PWM) to control the driving. 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. 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 power of the AC driving power output by the driving unit 12 is regarded as a driving output power in this embodiment, and the control unit 14 changes the amplitude and/or amplitude of the AC driving voltage V _{AC_OUT} by controlling the driving unit 12, for example. or sine wave frequency to adjust the drive output power to meet the power requirement of the motor 20 . It should be added that the way in which the control unit 14 controls the driving unit 12 to convert the DC input power into the AC driving power and the way in which the driving output power is adjusted are achieved using existing technologies and are not the focus of this patent specification. Therefore, The details will not be elaborated here.

When the driving unit 12 operates in the second working state and the motor 20 is in the generator state, the driving unit 12 is controlled by the control unit 14 to receive the AC side connection terminals 122 from the motor 20 . AC regenerated electric energy is then converted into DC regenerated electric energy, and the DC regenerated electric energy is output to the energy storage unit 13 through the DC side connection end 121 . More specifically, as shown in FIG. 2 , when the driving unit 12 operates in the second working state and the motor 20 is in the generator state, the driving unit 12 uses the three-phase rectifier bridge circuit to convert the motor 20 into the generator state. The received AC regenerative voltage V _{AC_GEN} corresponding to the AC regenerated electric energy is converted into a DC regenerative voltage V _{DC_GEN} corresponding to the DC regenerated electric energy, whereby the AC regenerated electric energy is converted into the DC regenerative electric energy.

The energy storage unit 13 includes, for example, a charge and discharge connection terminal 131 electrically connected to the DC side connection terminal 121 of the driving unit 12, and a plurality of supercapacitors (not shown) with positive electrodes electrically connected to the charge and discharge connection terminal 131. Moreover, the electric energy stored in the energy storage unit 13 is used as DC auxiliary electric energy in this embodiment. The supercapacitor may also be called an electric double layer capacitor, or EDLC for short, and the rated capacitance value of each supercapacitor may be, for example, 2.65 Farads, but is not limited thereto. It should be added that in other embodiments, depending on the power storage requirements of the energy storage unit 13 and the specifications of the supercapacitors, the number of supercapacitors included in the energy storage unit 13 may also be a single one. It is limited to this embodiment.

Further explanation of the energy storage unit 13 is that when the driving unit 12 operates 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 driving unit. 12 Through the DC regenerative energy output by the DC side connection terminal 121, a regeneration current I _GEN flows from the DC side connection terminal 121 of the driving unit 12 into the charge and discharge connection terminal 131 of the energy storage unit 13, thereby, The energy storage unit 13 stores the received DC regenerated electric energy as the DC auxiliary electric energy. On the other hand, when the driving 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 cause a second current I ₂ to flow from the The charging and discharging connection end 131 of the energy storage unit 13 flows into the DC side connection end 121 of the driving unit 12 , whereby the DC auxiliary power stored in the energy storage unit 13 is provided to the driving unit 12 so that the driving 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.

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

Referring to FIG. 3 , the operation mode of the motor 20 in the application of this embodiment will be described below with FIG. 3 .

In the application of this embodiment, the rotation speed of the motor 20 is, for example, automatically controlled by a programmable motor controller (not shown) and changes repeatedly with multiple working cycles T. FIG. 3 only shows one complete working cycle T, and the working cycle T shown in FIG. 3 is used to describe the rotation speed change mode of the motor 20 below.

In the working period T in FIG. 3 , the period during which the motor 20 operates in the motor state is regarded as a motor period T1 , and the period during which the motor 20 operates in the generator state is regarded as a generator period T2 . More specifically, in the application of this embodiment, the working period T includes the motor period T1 and the generator period T2 following the motor period T1 as shown in FIG. 3 . 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. For example, the time length of the motor period T1 can be, for example, is 3 seconds, and the time length of the generator period T2 can be, for example, 1 second, but is not limited to this. Therefore, the motor 20 is equivalent to periodically switching between the motor state and the generator state along with the working periods 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 rotation speed S1 is maintained within a predetermined rotation speed range is regarded as a constant speed operation interval t12 shown in FIG. 3 . More specifically, the motor period T1 includes the acceleration operation section t11 and the constant speed operation section t12 following the acceleration operation section t11 as shown in FIG. 3 . The initial rotation speed S0, the target rotation speed S1 and the predetermined rotation speed range are all preset. For example, the initial rotation speed S0 can be, for example, 0 RPM, the target rotation speed S1 can be, for example, 1200 RPM, and the predetermined rotation speed The range may be, for example, a range within plus or minus five percent of the target rotation speed S1 to cover the target rotation speed S1, but is not limited to this.

Then, after the constant speed operation interval t12 ends, the rotation speed of the motor 20 will, for example, drop from the predetermined rotation speed range to the initial rotation speed S0 during the generator period T2, and in the acceleration operation interval t11 of the next working cycle T It rises from the initial rotation speed S0 to the target rotation speed S1 again. In other words, the rotation speed of the motor 20 periodically changes back and forth between the initial rotation speed S0 and the target rotation speed S1 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. 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 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 of this embodiment in the duty 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 at the beginning of the working period T.

In this embodiment, the driving unit 12 periodically and repeatedly switches 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. 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, during the acceleration operation interval t11 of the motor period T1, the control unit 14 controls the rectifier unit 11 to continuously convert the AC input power from the AC power supply 10 into DC rectified power, and to pass the DC rectified power through the The DC output connection 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 to continue to receive the DC input power through the DC side connection terminal 121, convert the DC input power into the AC driving power, and convert the AC driving power through the The AC side connection terminal 122 is output to the motor 20 .

In particular, when the rotation speed of the motor 20 rises rapidly, the power consumed by the motor 20 will also rise rapidly. Therefore, in the acceleration operation interval t11, the driving output power of the driving unit 12 outputting the AC driving power will increase accordingly. As the rotation speed of the motor 20 increases to reach a maximum driving output power (for example: 15KW, but not limited to this). Further, when the driving output power of the driving unit 12 outputting the AC driving power increases, in the transient change, the third current I ₃ will increase with the increase of the driving output power, and the DC side connection end 121 The voltage (that is, the DC input voltage V _{DC_IN} ) will decrease as the drive output power increases, and is lower than the voltage of the charge and discharge connection terminal 131 of the energy storage unit 13 . In this case, in addition to the rectifier unit 11 outputs the DC rectified power to the outside of the driving unit 12, and the energy storage unit 13 will also discharge the driving unit 12 through the charging and discharging connection terminal 131 to form the second current _I2 . Thereby, the DC auxiliary electric energy stored in the energy storage unit 13 will be at least partially provided to the driving 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 t11. Decline within t11.

Therefore, in the acceleration operation interval t11, the driving unit 12 uses the DC rectified electric energy output by the rectifying unit 11 and the DC auxiliary electric energy output by the energy storage unit 13 as the DC input electric energy 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 the rectifier 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 accelerated operation interval t11, the drive unit 12 can output in the accelerated operation interval t11. The AC driving electric energy is sufficient to increase the rotation speed of the motor 20 to the target rotation speed S1 until the end of the acceleration operation interval t11.

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

On the other hand, during the constant speed operation interval t12, the control unit 14, for example, continues to compare the remaining power of the energy storage unit 13 with a preset high power threshold and a low power threshold that is less than the high power threshold. The values are compared to determine whether to control the rectifier unit 11 to output the DC rectified power. The control unit 14 obtains the current remaining power of the energy storage unit 13 by, for example, using the Coulomb measurement method. However, the control unit 14 may 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 and the low battery threshold can be implemented as two state of charge (State of charge) percentages, for example, and can be implemented as 75% and 25% respectively, but this is not the case. 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 rectification The unit 11 does not output the DC rectified power to the driving unit 12 (that is, even if the first current I ₁ is 0 amps), so that the energy storage unit 13 continues to discharge the driving unit 12 and causes the energy storage unit 13 to The energy storage percentage continues to decrease. In this case, the driving unit 12 only uses the DC auxiliary power as the DC input power to generate and output the AC driving power.

Then, until the control unit 14 determines that the remaining power of the energy storage unit 13 drops below the low power threshold, the control unit 14 controls the rectifier unit 11 to start outputting the DC rectified power to the driving unit 12 so that The energy storage unit 13 stops discharging. In this case, the driving unit 12 only uses the DC rectified electric energy as the DC input electric energy to generate the AC driving electric energy until the end of the constant speed operation interval t12 (equivalent to the motor period T1 end).

It should be added 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, which is sufficient to meet the power demand of the motor 20 . In addition, in other embodiments, the control unit 14 may also directly control the drive unit 12 to suspend output of the DC rectified power for a fixed period of time when entering the constant speed operation interval t12 from the acceleration operation interval t11 . For example, the DC rectified power will not be output until a specific time point in the constant speed operation interval t12 is reached, and the DC rectified power will be output only when the specific time point is reached. Therefore, the control unit 14 will not output the DC rectified power during the constant speed operation period. The method of controlling the driving unit 12 in the interval t12 is not limited to this embodiment.

After the constant speed operation interval t12 ends (that is, the motor period T1 ends), during the generator period T2, the control unit 14 controls the rectifier unit 11 not to output the DC rectified power, and the drive unit 12 operates in The second working state is to continue to receive the AC regenerative energy from the motor 20 through the AC side connection terminals 122, convert the AC regenerative energy into DC regenerative energy, and convert the DC regenerative energy through the DC side connection. The terminal 121 is output to the energy storage unit 13, so that the energy storage unit 13 stores all the DC regenerative electric energy received through the charge and discharge connection terminal 131 as DC auxiliary electric energy during the generator period T2. Moreover, the DC auxiliary electric 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 period T to drive the motor 20 .

It is worth noting that since the rotation speed of the motor 20 changes periodically in the application environment of this embodiment, the actual amount of AC regenerated electric energy generated by the motor 20 in each generator period T2 can be calculated by and/or measured, and is predictable. Therefore, by appropriately planning the low battery threshold and the discharge time of the energy storage unit 13 during the motor period T1, the energy storage unit 13 can be used during the motor period T1. Pre-discharge to the energy storage percentage corresponding to the low battery threshold, thereby ensuring that it has sufficient energy storage capacity during the generator period T2 to store all the AC regenerative energy generated by the motor 20 as DC auxiliary energy, In this way, this embodiment can avoid over-amplifying the total energy storage capacity of the energy storage unit 13 and achieve high utilization of the total energy storage capacity of the energy storage unit 13 . On the other hand, by causing the rectifier unit 11 and the energy storage unit 13 to simultaneously output the DC rectified power and the DC auxiliary power to the drive unit 12 respectively during the acceleration operation interval t11 of the motor period T1, this embodiment can When the speed of the motor 20 increases and the power consumption increases, the AC regenerative energy generated by the motor 20 during the generator period T2 of the previous working cycle T is utilized (that is, the energy storage unit 13 generates electricity during the previous generator period T2 The stored DC auxiliary electric energy) is used to drive the motor 20. Therefore, this embodiment can not only effectively recycle and reuse the AC regenerated electric energy generated when the motor 20 decelerates, but also reduce the operating time of the rectifier unit 11 in the acceleration operation interval t11. The first current I ₁ required to be output in the rectifier unit 11 thereby reduces the current stress that the power components (such as various power switches) in the rectifier unit 11 need to withstand, which helps to reduce the cost of the rectifier unit 11 . In addition, by reducing The first current I ₁ that the rectifier unit 11 needs to output 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 driving system 1 .

In the application of the second embodiment, what is different from the first embodiment is that the rotation speed of the motor 20 changes, for example, according to the user's manual operation of the working equipment, rather than changing periodically as shown in Figure 3. Therefore, there is no working period T with a fixed length of time. To be more clear, in the application of the second embodiment, the rotation speed of the motor 20 changes with no regularity and cannot be predicted. In other words, the respective time lengths of the motor period T1 and the generator period T2 are different in the second embodiment. In the example application, it changes randomly. On the other hand, in the application of the second embodiment, as long as the rotation speed of the motor 20 increases, it belongs to the acceleration operation zone, 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 charge and discharge 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 driving unit 12 Changes in the voltage value of the DC rectified voltage V _{DC_REC} .

Specifically, when the rectifier unit 11 does not output the DC rectified power (that is, the first current I ₁ is 0 amps), when the control unit 14 determines that the voltage value of the DC rectified voltage V _{DC_REC} is within a period When the voltage drop exceeds a voltage change threshold within a predetermined period of time (equivalent to a falling slope of the DC rectified voltage V _{DC_REC} exceeding a falling slope threshold), it means that the driving unit 12 is operating in the first working state and is responding to the DC input. The demand for electric energy increases rapidly (that is, the rotation speed of the motor 20 is rising rapidly, resulting in a rapid increase in power consumption), which causes the DC rectified voltage V _{DC_REC} to rapidly decrease. In this case, the control unit 14 controls the rectifier unit 11 to start outputting the DC rectified power, so that the driving unit 12 can receive sufficient DC input power from the rectifier unit 11 and the energy storage unit 13 at the same time, and output Sufficient AC driving power is provided to drive the motor 20 . The predetermined time length and the voltage change threshold can be freely set and adjusted according to the power characteristics of the motor 20 when accelerating, so this embodiment is not particularly limited in this regard.

On the other hand, when the rectifier unit 11 outputs the DC rectified power (that is, the first current I ₁ is greater than 0 amps), when the control unit 14 determines that the voltage value of the DC rectified voltage V _{DC_REC} exceeds a high At the voltage threshold of the rated DC voltage value, it means that the drive unit 12 is operating in the second working state and outputs the DC regenerative energy through the DC side connection terminal 121 (that is, it means that the motor 20 is generating AC regenerative energy. ), causing the voltage of the DC regenerative voltage V _{DC_GEN} (shown in Figure 2) to rise, and also causing the voltage value of the DC rectified voltage V _{DC_REC} (shown in Figure 2) to rise. In this case, the control unit 14 controls the rectifier unit 11 to stop outputting the DC rectified power, so that the energy storage unit 13 receives the DC regenerative power output by the driving unit 12 and stores all of it as auxiliary DC power.

In this way, even if the speed change 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 rebound electric energy generated by the motor 20 is stored as DC auxiliary electric energy, and then when the motor 20 is in the motor state and the rotation speed increases, the DC auxiliary electric energy stored in the energy storage unit 13 is used to drive the motor 20 to operate.

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 driving system 1 .

In the third embodiment, in addition to the rectifier 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 an electrically connected drive unit 12 and the bidirectional voltage conversion unit 15 which is used as a switching unit between the energy storage unit 13 and the energy storage unit 13 . Moreover, different from the first embodiment, the control unit 14 in the third embodiment is electrically connected to the bidirectional voltage conversion unit 15 and the driving unit 12 , but is not electrically connected to the rectifying unit 11 .

The bidirectional voltage conversion unit 15 may, for example, be implemented as a bidirectional buck-boost converter, or other existing topologies that can achieve bidirectional DC voltage conversion. The bidirectional voltage conversion unit 15 includes a first end electrically connected to the DC side connection end 121 of the driving unit 12 , and a second end electrically connected to the charge and discharge connection end 131 of the energy storage unit 13 . Moreover, in this embodiment, the first terminal serves as a high-voltage side connection terminal 151 included in the bidirectional voltage conversion unit 15 , and the second terminal serves as a low-voltage side connection terminal included in the bidirectional voltage conversion unit 15 . Connector 152.

The bidirectional voltage conversion unit 15 can switch between a boost operating state, a buck operating state and a shutdown state under the control of the control unit 14 .

Specifically, when the bidirectional voltage conversion unit 15 operates in the boosting operating 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 Electrical energy is allowed to be transmitted from the low-voltage side connection terminal 152 to the high-voltage side connection terminal 151 . Moreover, when the bidirectional voltage conversion unit 15 operates in the boosting working state, the bidirectional voltage conversion unit 15 will perform a boost process on the electric energy received through the low-voltage side connection terminal 152, and then use the boosted power to 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 step up the DC voltage received by the low-voltage side connection terminal 152 to 311 volts according to the pulse width modulation control of the control unit 14 and then transmit it through the high-voltage side connection terminal. 151 output, but is not limited to this.

On the other hand, when the bidirectional voltage conversion unit 15 operates in the buck operating 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 Electrical energy is allowed to be transmitted from the high-voltage side connection terminal 151 to the low-voltage side connection terminal 152 . Moreover, when the bidirectional voltage conversion unit 15 operates in the buck operating state, the bidirectional voltage conversion unit 15 performs a voltage reduction process on the electric energy received through the high-voltage side connection terminal 151, and then converts the voltage through the voltage reduction process. The processed power is output through the low-voltage side connection terminal 152 , so that the voltage output by the bidirectional voltage conversion unit 15 through the low-voltage side connection terminal 152 is lower than the voltage received by the high-voltage side connection terminal 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 according to the pulse width modulation control of the control unit 14 and then transmit it through the low-voltage side connection terminal. 152 output, but not limited to this.

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 to be transmitted 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 mode 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 changes as shown in FIG. 3 , which will not be repeated here.

Referring to FIGS. 3 to 5 simultaneously, the operation mode of the electric energy conversion and driving system 1 of the third embodiment in the duty cycle T of FIG. 3 will be described below. Similarly, it is assumed here that the energy storage unit 13 has pre-stored DC auxiliary power at the beginning of the working period T.

In the third embodiment, the same as the first embodiment, the driving unit 12 is also 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. Periodically and repeatedly switching between periods, that is, operating in the first working state during the motor period T1 and operating in the second working state during the generator period T2.

First, during the acceleration operation interval t11 of the motor period T1, the rectifier unit 11 receives the AC input power from the AC power supply 10 through the two AC input connection 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 connection terminal 112 . On the other hand, the control unit 14 controls the bidirectional voltage conversion unit 15 to operate in the boost operating 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 energy storage unit 13 supplies the DC auxiliary power, the bidirectional voltage conversion unit 15 is controlled by the control unit 14 to perform a boosting 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, during 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 during 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 end 121, and The DC input power is converted into AC driving power, and the AC driving power is output to the motor 20 through the AC side connection terminals 122. As shown in FIG. 4, the driving unit 12 is configured by corresponding to the DC The DC input voltage V _{DC_IN} of the input electric energy is converted into the AC driving voltage V _{AC_OUT} corresponding to the AC driving electric energy, so that the DC input electric energy is converted into the AC driving electric energy. Similar to the first embodiment, the driving unit 12 uses the DC rectified power and the DC auxiliary power 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 speed of the motor 20 . The AC driving electric energy at the target speed S1 is until the end of the acceleration operation interval t11. At this time, the current 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, during the constant speed operation interval t12 of the motor period T1, the drive unit 12 continues to operate in the first operating mode to continue to receive the DC input power through the DC side connection end 121. The DC input electric energy is converted into AC driving electric energy, and the AC driving electric energy is output to the motor 20 through the AC side connection terminals 122, so that the rotation speed of the motor 20 can be maintained within the predetermined rotation speed range.

On the other hand, during the constant speed operation interval t12, the control unit 14, for example, continues to compare 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 operating in the boosting operating 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 operating in the rising state. voltage working state, so that the DC auxiliary power continues to be provided from the energy storage unit 13 to the driving unit 12 through the bidirectional voltage conversion unit 15. At this time, the current magnitude of the third current I ₃ 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 electric energy, and the driving unit 12 only uses the DC rectified electric energy output by the rectifier unit 11 as the DC input electric energy to generate the AC driving electric energy until the end of the constant speed operation interval t12 (equivalent to the end of the motor period T1) , at this time, the fourth current I ₄ is substantially 0 ampere, and the current magnitude of the third current I ₃ is equal to the first current I ₁ .

It should be added that in other implementations, the control unit 14 may also control the bidirectional voltage conversion unit 15 to continue operating in the boosting operation when entering the constant speed operation interval t12 from the acceleration operation interval t11 . state, and when the specific time point of the constant speed operation interval t12 is reached, the bidirectional voltage conversion unit 15 is controlled to switch to the off state. Alternatively, the control unit 14 may, for example, control the bidirectional voltage conversion unit 15 to operate in the boosting operating state before the end of the constant speed operation interval t12. Therefore, the control unit 14 controls the voltage conversion unit 15 in the constant speed operation interval t12. The operation mode of the bidirectional voltage conversion unit 15 is not limited to 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 use the AC The side connection terminal 122 receives the AC regenerated electric energy from the motor 20, converts the AC regenerated electric energy into the DC regenerated electric energy, and outputs the DC regenerated electric energy to the bidirectional voltage conversion unit 15 through the DC side connection terminal 121, wherein , as shown in FIG. 5 , the driving unit 12 converts the AC regenerated electric energy into the DC regenerated electric energy by converting the AC regenerated electric energy V _{AC_GEN} into the DC regenerated voltage V _{DC_GEN} corresponding to the DC regenerated electric energy. Regenerate electrical energy. On the other hand, when the generator period T2 begins, the control unit 14 controls the bidirectional voltage conversion unit 15 to switch to the buck operating state, so that a regenerative current I _GEN flows from the DC side connection end 121 of the drive unit 12 flows into the high-voltage side connection terminal 151 of the bidirectional voltage conversion unit 15. Therefore, during the generator period T2, when the bidirectional voltage conversion unit 15 receives the DC regenerative energy from the driving unit 12 through the high-voltage side connection terminal 151 At this time, the bidirectional voltage conversion unit 15 is controlled by the control unit 14 to perform the step-down processing on the DC regenerated electric energy, and then outputs the step-down processed DC regenerated electric energy to the energy storage through the low-voltage side connection end 152 unit 13, so that the energy storage unit 13 stores all the DC regenerative electric energy received through the bidirectional voltage conversion unit 15 during the generator period T2 as DC auxiliary electric energy. Moreover, the DC auxiliary electric 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 period T to drive the motor 20 .

The electric energy conversion and driving system 1 of the third embodiment can also use the regenerated 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 The power components in the drive unit 12 need to withstand the current stress in the accelerated operation interval t11, and can also reduce the power loss of the rectifier unit 11 in the accelerated operation interval t11, and achieve 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 endured by the energy storage unit 13, so that the energy storage unit 13 can be implemented with a supercapacitor with lower voltage resistance specifications, 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 driving system 1 .

In the application of the fourth embodiment, just like the application of the second embodiment, the rotation speed of the motor 20 changes irregularly and cannot be predicted.

In the fourth embodiment, the control unit 14 detects changes in the current value of the first current I ₁ through, for example, the DC output connection end 112 of the rectifier unit 11 .

Specifically, when the bidirectional voltage conversion unit 15 operates in the buck operating state or the off state, when the control unit 14 determines that the current value of the first current I ₁ rises above When a current changes threshold value (equivalent to the rising slope of the first current I ₁ exceeding 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 ( This means that the rotational speed of the motor 20 is rising rapidly, resulting in a rapid increase in power consumption). In this case, the control unit 14 controls the bidirectional voltage conversion unit 15 to switch to the boost operating state, so that the energy storage unit 13 discharges the driving unit 12 through the bidirectional voltage conversion unit 15, so that the storage unit The stored DC regenerative energy can be provided to the driving unit 12 through the bidirectional voltage conversion unit 15, whereby the driving unit 12 can receive sufficient DC input from the rectifier unit 11 and the bidirectional voltage conversion unit 15 at the same time. electric energy, and outputs sufficient AC driving electric energy to drive the motor 20 . The predetermined time length and the current change threshold can be freely set and adjusted according to the power characteristics of the motor 20 when accelerating, so this embodiment is not particularly limited in this regard.

On the other hand, when the bidirectional voltage conversion unit 15 operates in the boost operating 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. When the voltage threshold value is reached, it means that the drive unit 12 is operating in the second working state and outputs the DC regenerative energy through the DC side connection terminal 121 (that is, it means that the motor 20 is generating AC regenerative energy), resulting in the The voltage value of the DC rectified voltage V _{DC_REC} increases. In this case, the control unit 14 controls the bidirectional voltage conversion unit 15 to switch to the buck operating state, so that the energy storage unit 13 receives the DC regenerative energy output by the driving unit 12 through the bidirectional voltage conversion unit 15, And store all of it as auxiliary DC power.

In this way, even if the rotation 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. The AC rebound electric energy generated by the motor 20 is stored as DC auxiliary electric energy through the bidirectional voltage conversion unit 15, and then the DC auxiliary electric energy stored in the energy storage unit 13 is used when the motor 20 is in the motor state and the speed increases. The motor 20 is driven to operate.

It is supplementary to note that in a similar implementation of the fourth embodiment, when the bidirectional voltage conversion unit 15 operates in the buck operating state or the off state, the control unit 14 can also, for example, through the driver The DC side connection end 121 of the unit 12 detects changes in the current value of the third current I ₃ and determines whether to control the bidirectional voltage conversion unit 15 to switch to the boosting operation according to the slope change of the third current I ₃ condition.

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 regenerated 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 rotational speed increases, the energy storage unit 13 and the rectifier unit 11 simultaneously output DC auxiliary power and DC rectifier power to drive the motor, whereby the power conversion and drive system 1 can not only effectively utilize the energy generated by the motor 20 AC regenerates electric energy to reduce the overall power consumption of the electric energy conversion and drive system 1, and also reduces the current stress that the rectifier unit 11 needs to withstand when the speed of the motor 20 increases and the power loss of the rectifier unit 11 to achieve better results. It has the best energy-saving efficiency, so it can indeed achieve the purpose of the present invention.

However, the above are only examples of the present invention, and should not be used to limit the scope of the present invention. All simple equivalent changes and modifications made based on 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 this invention.

1: Electric energy conversion and drive system 11: Rectifier unit 111: AC input connection terminal 112: DC input connection terminal 12: Drive unit 121: DC side connection terminal 122: AC side connection terminal 13: Energy storage unit 131: Charge and discharge connection terminal 14: Control unit 15: Bidirectional voltage conversion unit 151: High-voltage side connection terminal 152: Low-voltage side connection terminal 10: AC power supply 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 : second current I ₃ : third current I _GEN : regenerative current I ₄ : fourth current T: working cycle T1: motor Period t11: Acceleration operation interval t12: Constant speed operation interval T2: Generator period S0: Initial speed S1: Target speed

Other features and effects of the present invention will be clearly presented in the embodiments with reference to the drawings, in which: Figure 1 is a block diagram illustrating a first embodiment of the power conversion and drive system of the present invention, as well as an AC power supply and a motor suitable for operating in conjunction with the first embodiment. Moreover, what is shown in Figure 1 is The operation of a driving unit included in the first embodiment when operating in a first working state; Figure 2 is a block diagram illustrating the operation of the first embodiment when the driving unit operates in a second working state; Figure 3 is a schematic diagram used to represent the change in rotation speed of the motor during a working cycle; Figure 4 is a block diagram illustrating a third embodiment of the power conversion and drive system of the present invention, as well as an AC power supply and a motor suitable for operating in conjunction with the third embodiment, and what is shown in Figure 4 is The operation 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 operation of the third embodiment when the driving unit operates in the second working state.

1: Electric energy conversion and drive system

11: Rectifier unit

111: AC input connection terminal

112: DC input connection terminal

12: Drive unit

121: DC side connection terminal

122: AC side connection terminal

13: Energy storage unit

131: Charge and discharge connection terminal

14:Control unit

10:AC power supply

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 : second current

I ₃ : third current

Claims (9)

An electric energy conversion and drive system suitable for electrical connection between an AC power source and a motor. The motor can operate in a motor state that operates by consuming electrical energy, and a generator state that generates electrical energy by rotating. The two periods in which the motor operates in the motor state and the generator state are regarded as a motor period and a generator period respectively, and the period in which the motor operates in the motor state and the rotational speed increases is regarded as a period included in the motor. During the acceleration operation range; 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 to the rectifier unit and suitable for electrical connection with the motor; An energy storage unit is electrically connected to the driving unit and is used to store the electric energy generated by the motor during the generator period as DC auxiliary electric energy, and to discharge it at least during the acceleration operation interval of the electric 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: during the acceleration operation interval of the motor, control the rectifier unit to use the electric energy provided by the AC power supply to generate and output DC rectified electric energy to The drive unit controls the drive unit to convert DC input power into AC drive power and output the AC drive power to the motor, wherein the DC input power includes both the DC rectified power and the DC rectified power in the acceleration operation range. DC auxiliary power. The electric energy conversion and drive system as claimed in claim 1, wherein the acceleration operation interval is a 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 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 to: During the constant speed operation range of the motor, when the remaining power of the energy storage unit is higher than a high power threshold, the rectifier unit is controlled not to output the DC rectified power to the drive unit, so that the energy storage unit The unit continues to discharge during the constant speed operation range of the motor, and causes the drive unit to only use the DC auxiliary power as the DC input power to generate the AC drive power; and During the constant speed operation period of the motor, when the remaining power of the energy storage unit is lower than the low power threshold that is less than the high power threshold, the rectifier unit is controlled to output 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 drive 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 to: during the period of the generator, control The driving unit receives the AC regenerated electric energy, converts the AC regenerated electric energy into DC regenerated electric energy, and outputs the DC regenerated electric energy to the energy storage unit for the energy storage unit to store the DC regenerated electric energy as the DC auxiliary electrical energy. The power conversion and drive system as described in claim 1, wherein the motor periodically switches 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 converts the AC regenerated electrical energy into the DC regenerated electrical energy and outputs it to the energy storage unit is regarded as a second operating state of the driving unit. working state, and the control unit controls the driving unit to periodically and repeatedly switch 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 electric energy conversion and drive system suitable for electrical connection between an AC power source and a motor. The motor can operate in a motor state that operates by consuming electrical energy, and a generator state that generates electrical energy by rotating. The two periods in which the motor operates in the motor state and the generator state are regarded as a motor period and a generator period respectively, and the period in which the motor operates in the motor state and the rotational speed increases is regarded as a period included in the motor. During the acceleration operation range; the electric energy conversion and drive system includes: A rectifier unit is adapted to be electrically connected to the AC power supply, and is used to generate and output DC rectified power using the power 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 includes a first end electrically connected to the driving unit, and a second end; An energy storage unit, electrically connected to the second end of the switch unit, and used to store the electric energy generated by the motor during the generator period as DC auxiliary electric energy, and at least during the acceleration operation interval of the motor period Discharge, so that the DC auxiliary power is provided to the driving unit through the switching 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 the DC input power into an AC drive power and output the AC drive power to the motor, wherein the DC input The electric energy in the accelerated operation interval includes both the DC rectified electric energy and the DC auxiliary electric energy. The electric energy conversion and drive system as claimed in claim 5, wherein the acceleration operation interval is a 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 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 to: During the constant speed operation range of the motor, when the remaining power of the energy storage unit is higher than a high power threshold, the first end and the second end of the switch unit are controlled to continue to be electrically connected to each other, and Allowing the DC auxiliary power to continue to be provided from the energy storage unit to the driving unit through the switching unit; and During the constant speed operation interval of the motor, when the remaining power of the energy storage unit is lower than the low power threshold that is less than the high power threshold, the first end and the second end of the switch unit are controlled. The terminals are not electrically connected to each other, so that the energy storage unit stops outputting the DC auxiliary power. The electric energy conversion and drive 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 a low-voltage side connection terminal of the bidirectional voltage conversion unit; When the bidirectional voltage conversion unit operates in a boost operating 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 data from the energy storage unit through the low-voltage side connection terminal. of the DC auxiliary electric energy, perform a boosting process on the DC auxiliary electric energy, and output the boosted DC auxiliary electric energy to the drive unit through the high-voltage side connection terminal; and The control unit controls the bidirectional voltage conversion unit when the electric motor is in the acceleration operation range and the electric motor is in the constant speed operation period and the remaining power of the energy storage unit is higher than a high power threshold. Operate in this boosted 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 to: control during the generator period The first end and the second end of the switch unit are electrically connected to each other, and the driving unit is controlled to receive the AC regenerated electric energy, convert the AC regenerated electric energy into DC regenerated electric energy, and pass the DC regenerated electric energy through the switch unit Output to the energy storage unit for the energy storage unit to store the DC regenerated electric energy as the DC auxiliary electric energy. The electric energy conversion and drive system as described in 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 a low-voltage side connection terminal of the bidirectional voltage conversion unit; When the bidirectional voltage conversion unit operates in a buck operating state, the first end and the second end of the switch unit are electrically connected to each other, and the bidirectional voltage conversion unit receives the signal from the driving unit through the high-voltage side connection terminal. The DC regenerated electric energy is subjected to a voltage reduction process, and the DC regenerated electric energy that has undergone the voltage reduction process is output to the energy storage unit through the low-voltage side connection terminal; and During the generator period, the control unit controls the bidirectional voltage conversion unit to operate in the buck operating state.

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